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UNIVERSITY OF CINCINNATI
Date: April 24, 2007
I, Niranjan Deshpande ,
hereby submit this work as part of the requirements for the degree of:
Master of Science
in:
Environmental Engineering
It is entitled:
Dispersant Effectiveness on Oil Spills:
Impact of Environmental Factors
This work and its defense approved by:
Chair: Dr. George A. Sorial
Dr. Makram T. Suidan
Dr. Margaret J. Kupferle
DISPERSANT EFFECTIVENESS ON OIL SPILLS: Impact of Environmental Factors
A thesis submitted to the
Division of Research and Advanced Studies of the University of Cincinnati
In partial fulfillment of the requirements for the degree of
MASTER OF SCIENCE
In the department of Civil and Environmental Engineering Of the college of Engineering at the University of Cincinnati
2007
by
Niranjan Deshpande B.E. Civil Engineering, Pune University, 2004
Committee chair: Dr. George Sorial
i
ABSTRACT
When a dispersant is applied to an oil slick, its effectiveness in dispersing the
spilled oil depends on various factors such as oil properties, wave mixing energy,
temperature of both oil and water, and salinity of the water. Estuaries represent water
with varying salinities. In this study, three salinity values in the range of 10-34 ppt were
investigated, representing potential salinity concentrations found in typical estuaries.
Three oils were chosen to represent light refined oil, light crude oil and medium crude
oil. Each of the oils was tested at three weathering levels to represent maximum, medium
and zero weathering. Two dispersants were chosen for evaluation. A modified
trypsinizing flask termed the ‘Baffled Flask’ was used for conducting the experimental
runs. A full factorial experiment was conducted for each oil to investigate the effect of
salinity on three environmental factors: temperature (2 levels), oil weathering (3 levels)
and mixing energy (150,200 and 250 rpm). Each experiment was replicated four times in
order to evaluate the accuracy of the test. Evaluations were conducted to study the effect
of different variables like salinity, weathering, mixing speed and temperature on
dispersant effectiveness. Statistical analysis of the data was performed separately on each
of the nine oil-dispersant combinations, which revealed the significant factors for each of
the combinations. A linear regression model was fit to the experimental data collected.
Keywords: Baffled Flask, dispersant effectiveness, salinity, mixing speed, temperature.
ii
iii
ACKNOWLEDGEMENTS
I would to thank first and foremost my family for all the motivation and support they
provided to me, especially my brother Nikhil, for the support and encouragement.
I would like to thank my advisor Dr. George Sorial for always being there for me when I
needed him, and for keeping an eye on me, and more importantly, being a very nice
person to work with. I cannot forget my group partners Qiuli Lu, Daekeun Kim, Hao
Zhang, Zhangli Cai (Charlie) Ashraf Hosni, Rangesh Srinivasan, and Rachel Rhodes for
all their help, support and friendship. They have really made the environmental chemistry
lab feel like home.
I would also like to thank Dr. Makram Suidan and Dr. Margaret Kupferle for serving on
my committee. I would also like to thank the EPA for the funding received during these
two years under USEPA Task Order 70.
A special thanks to Yogesh Kandlur, for all his help with statistics, and Pamela Heckel,
for proofreading my thesis. I really appreciate the time, effort and suggestions they have
given.
Of course I need to thank all my lab mates for helping me out, I wouldn’t have been able
to manage without any of you. In alphabetical order: Shirish Agarwal, Maria Antoniou,
iv
Ahmed Hosni, Gina Lamendella, Ian Laseke, Alicia Mansour, Ashok Matta, Marc-Andre
Philibert, Aditya Rastogi, Bhargavi Subramanian, and Jiefei Yu.
And finally I would like to mention the following people for giving me their friendship
and making my time in Cincinnati invaluable (also in alphabetical order): Ezgi Akpinar,
Maria Antoniou, Tejas Arurkar and the members of the UC cricket team, Emina
Atikovic, David Bailey and the members of my soccer team, Elif Bengu, Abhijeet
Deshpande, Hélène Deval, Yann Ferrand, Ines Ivicic, Gina Lamendella, Ian Laseke,
Chris Luedekar, Sujit Mahajan, Alicia Mansour, Amol Padmawar, Aniruddha Palsule,
Marc-Andre Philibert, Bhargavi Subramanian , Jiefei Yu, Rachel Zerkle, and YueChen
Zhao.
v
TABLE OF CONTENTS
ABSTRACT……………………………………………………………………………….i
ACKNOWLEDGEMENTS……………………………………………………………... iii
INDEX…………………………………………………………………………………….v
LIST OF TABLES……………………………………………………………………….vii
LIST OF FIGURES………………………………………………………………………ix
Chapter 1 Introduction
1.1 Introduction............................................................................................................... 1
1.2 Purpose of Study....................................................................................................... 2
1.3 Literature review....................................................................................................... 3
1.4 Research Objectives................................................................................................ 10
1.5 References............................................................................................................... 12
Chapter 2 Experimental Materials and Methods .......................................................... 16
2.1 Materials ................................................................................................................. 17
2.1.1 Analytical Instruments .................................................................................. 17
2.1.2 Reagents........................................................................................................ 18
2.2 Methods................................................................................................................... 21
2.2.1 Weathering of oils......................................................................................... 21
2.2.2 Oil Standards Procedure: .............................................................................. 21
2.2.3 Dispersant Effectiveness procedure:............................................................. 23
2.2.4 Sample Analysis............................................................................................ 23
2.2.5 QA/QC Checks ............................................................................................. 24
vi
2.2.6 Calculation Procedures for Experimental Samples....................................... 25
2.2.7 Viscosity measurements................................................................................ 26
Chapter 3 Dispersant Effectiveness at 10˚C................................................................... 28
3.1 Introduction............................................................................................................. 29
3.2 Dispersant Effectiveness procedure........................................................................ 29
3.3 Sample Analysis...................................................................................................... 30
3.4 Discussion ............................................................................................................... 30
Chapter 4 Dispersant Effectiveness at 16 ˚C.................................................................. 45
4.1 Introduction............................................................................................................. 46
4.2 Dispersant Effectiveness procedure........................................................................ 46
4.3 Sample Analysis...................................................................................................... 47
4.4 Discussion ............................................................................................................... 47
Chapter 5 Viscosity Determination of the Test Oils..................................................... 62
5.1 Abstract ................................................................................................................... 63
5.2 Introduction............................................................................................................. 63
5.3 Materials and Methods............................................................................................ 64
5.4 Experimental Results .............................................................................................. 65
5.5 Regression............................................................................................................... 66
5.6 References............................................................................................................... 73
Chapter 6 Statistical Analysis of Experimental Data .................................................... 74
6.1 Introduction............................................................................................................. 75
6.2 Factorial Experimental Design ............................................................................... 75
6.3 Analysis of Variance (ANOVA)............................................................................. 76
vii
6.4 Empirical Relationship............................................................................................ 77
6.5 Comparison with Previous study ............................................................................ 84
6.6 Correlation of Dispersant effectiveness to Oil viscosity......................................... 89
6.7 References............................................................................................................... 98
Chapter 7 Conclusions and Recommendations ............................................................ 99
7.1 Conclusions........................................................................................................... 100
7.2 Recommendations................................................................................................. 101
Appendix A1 Experimental Data.................................................................................. 103
Appendix A2 Results of ANOVA ................................................................................. 158
Appendix A3 Compositions and Physical properties of Oils ..................................... 164
Appendix A4 Results of ANOVA for Viscosity Correlation ....................................... 167
viii
LIST OF TABLES
Table 2.1 Major Ion Composition of “Instant Ocean” Synthetic Sea Salt........................ 20
Table 2.2: Six point calibration curve for three oils ......................................................... 22
Table 5.1 Calibration constants for Viscometers .............................................................. 66
Table 5.2 Viscosity measurements of oils at various temperatures .................................. 66
Table 5.3 Parameters obtained for the three test oils ........................................................ 67
Table 5.4 Comparison for South Louisiana Crude Oil (SLC) .......................................... 68
Table 5.5 Comparison for Prudhoe Bay Crude Oil (PBC) ............................................... 69
Table 5.6 Comparison for No.2 Fuel Oil (2FO) ............................................................... 70
Table 5.7 Comparison of Model with Reported Viscosities............................................. 71
Table 6.1 Significant Factors for Various Oil-Dispersant Combinations for 2
Temperatures (10&16 ˚C)................................................................................................. 77
Table 6.2 Coefficients of Regression equations ............................................................... 79
Table 6.3 Coefficients of Regression equations ............................................................... 91
ix
LIST OF FIGURES
Figure 2.1 Baffled Flask Test Apparatus .......................................................................... 19
Figure 2.2 Cannon-Fenske Viscometer............................................................................. 27
Figure 3.1 Effect of Salinity and Weathering of SLC for dispersant ‘A’ ......................... 36
Figure 3.2 Effect of Salinity and Weathering of SLC for dispersant ‘B’ ......................... 37
Figure 3.3 Effect of Salinity and Weathering of SLC for dispersant ‘C’ ......................... 38
Figure 3.4 Effect of Salinity and Weathering of PBC for dispersant ‘A’......................... 39
Figure 3.5 Effect of Salinity and Weathering of PBC for dispersant ‘B’ ......................... 40
Figure 3.6 Effect of Salinity and Weathering of PBC for dispersant ‘C’ ......................... 41
Figure 3.7 Effect of Salinity and Weathering of 2FO for dispersant ‘A’ ......................... 42
Figure 3.8 Effect of Salinity and Weathering of 2FO for dispersant ‘B’ ......................... 43
Figure 3.9 Effect of Salinity and Weathering of 2FO for dispersant ‘C’ ......................... 44
Figure 4.1 Effect of Salinity and Weathering of SLC for dispersant ‘A’ ......................... 53
Figure 4.2 Effect of Salinity and Weathering of SLC for dispersant ‘B’ ......................... 54
Figure 4.3 Effect of Salinity and Weathering of SLC for dispersant ‘C’ ......................... 55
Figure 4.4 Effect of Salinity and Weathering of PBC for dispersant ‘A’......................... 56
Figure 4.5 Effect of Salinity and Weathering of PBC for dispersant ‘B’ ......................... 57
Figure 4.6 Effect of Salinity and Weathering of PBC for dispersant ‘C’ ......................... 58
Figure 4.7 Effect of Salinity and Weathering of 2FO for dispersant ‘A’ ......................... 59
Figure 4.8 Effect of Salinity and Weathering of 2FO for dispersant ‘B’ ......................... 60
Figure 4.9 Effect of Salinity and Weathering of 2FO for dispersant ‘C’ ......................... 61
Figure 5.1 Comparisons of Viscosities of the Test Oils ................................................... 72
Figure 6.1 Comparison of Estimated & Experimental Dispersant Effectiveness-SLC .... 81
x
Figure 6.2 Comparison of Estimated & Experimental Dispersant Effectiveness-PBC.... 82
Figure 6.3 Comparison of Estimated & Experimental Dispersant Effectiveness-2FO .... 83
Figure 6.4 Comparison for No.2 Fuel Oil......................................................................... 86
Figure 6.5 Comparison for Prudhoe Bay Crude Oil ......................................................... 87
Figure 6.6 Comparison for South Louisiana Crude Oil .................................................... 88
Figure 6.7 Comparison of Estimated & Experimental dispersant effectiveness-2FO ...... 92
Figure 6.8 Comparison of Estimated & Experimental dispersant effectiveness-PBC...... 93
Figure 6.9 Comparison of Estimated & Experimental dispersant effectiveness-SLC...... 94
Figure 6.10 Comparison for No.2 Fuel Oil....................................................................... 95
Figure 6.11 Comparison for Prudhoe Bay Crude Oil ....................................................... 96
Figure 6.12 Comparison for South Louisiana Crude Oil…………………………….......97
Chapter 1
Introduction
1
1.1 Introduction
Transportation of petroleum products and offshore drilling around the world are
the most significant causes for oil spills in the environment. These spills can be results of
equipment malfunction, human carelessness, or natural causes. Oil spills at sea can affect
the water column, sediments and shorelines; oil spilled on water can harm organisms that
live on or around the water surface and also those that live under the water surface.
Effects depend in large part on the ultimate location of the oil as well as its
chemical composition at the time of interaction with the biota. Oil slicks usually spread
very rapidly to a large area due to the action of gravitational and viscous forces, and
require a quick response(Hoult 1972). Four cleanup strategies typically considered are (1)
mechanical cleanup or recovery, (2) burning, (3) bioremediation, and (4) treatment with
chemical dispersants (NRC 1989a; NRC 1989b).
The use of chemical dispersants to counter the effects of an oil spill has many
benefits when compared to other response options. Dispersants do not eliminate the
problem of an oil spill but reduce the overall impact of the spill on the environment.
Chemical dispersants are made up of surfactants, solvents, and additives, which are
usually sprayed onto the slick to remove the oil from the surface and disperse it into the
water column at very low concentrations. This accelerates the natural degradation of oils
and significantly reduces the impact on the shorelines and the aquatic habitat. The
essential components in dispersant formulations are surfactant, which contain both oil-
compatible (lipophilic) and water-compatible (hydrophilic) groups. Following successful
application of a chemical dispersant formulation to an oil slick, the surfactant molecules
will reside at oil-water interfaces and reduce the oil-water interfacial surface tension. The
2
presence of minimal mixing energy provided by wave or wind action disperses the oil as
small droplets into the underlying water column. Such dispersion leads to dilution of the
oil in the water and increased oil-water interfacial surface area, which favors microbial
degradation of the oil. The purpose is to remove oil from the water surface and dilute and
degrade it to non-problematic concentrations in an underlying water column.
Dispersant effectiveness is the ratio of oil that the chemical will disperse into the
water column compared to the amount of oil that remains on the surface. This is what
determines the selection and usage of dispersants. The National Contingency Plan (NCP)
Product schedule lists dispersants which are at least 45% effective (50 ± 5%) in
dispersing Prudhoe Bay and South Louisiana crude oils in the laboratory (Sorial et al.
2004c). Many factors influence dispersant effectiveness, including oil composition,
mixing energy, oil weathering, dispersant type and amount applied, temperature, and
salinity of water.
Salinity of the sea is considered to be constant between 34-35 ppt; however, the
salinity of water in estuaries varies due to the mixing of fresh water. To take into account
these differences, two other salinities (viz: 20 ppt and 10 ppt) were also considered.
1.2 Purpose of Study
To assess the impacts of dispersant usage on oil spills, the US EPA is developing
a simulation model called the EPA Research Object-Oriented Oil Spill (ERO3S) Model.
This model simulates a portion of the oil slick behavior. Due to physical and chemical
interactions between the oil and the sea, this behavior has to be based on empirical data.
3
Therefore the main aim of the project is to create a set of empirical data to serve as an
input to the ERO3S model. The first two phases of the project looked at the effectiveness
of the dispersion caused by changes in temperature, oil composition, oil weathering,
dispersant type, rotational speed of the Baffled Flask, and salinity. The results obtained
indicated the need for obtaining data that will more strongly establish the temperature
behavior (Chandrasekar 2004).
1.3 Literature review
The concept of applying chemical dispersants to combat oil spills has been around
for decades. Oil spill dispersants have been used to enhance the rate of natural dispersion
of oil spills at sea. Dispersants break up the oil slick from the water surface and dilute the
oil into small droplets into the water column. The large increase in the oil water interface
due to droplet formation increases the biodegradation of the oil by naturally occurring
micro-organisms. In 1973 (Canevari 1973)worked on developing “The Next Generation”
chemical dispersants. The idea was to develop dispersants requiring little or no mixing
energy, which approached spontaneous emulsification. Canevari identified mixing as the
limiting step rather than application. Thus came the era of self-mixing dispersants.
In 1989, the National Research Council (NRC) conducted a comprehensive
review of various laboratory, meso-scale, and field tests that have been used to assess
dispersant effectiveness (NRC 1989b). The report pointed out a wide range of conditions
of oil-dispersant mixing, turbulence, droplet size distribution, and droplet coalescence
and resurfacing. The review also noted that understanding the interactions among these
phenomena is fundamental to determining why dispersants work or do not work.
4
Furthermore, it was also noted that the relative complexity of a large scale apparatus
means that performance of multiple testing events in short periods of time is not possible.
A variety of factors influence the ability of dispersants to disperse oil into water.
Both crude and petroleum products are complex mixtures of hydrocarbon compounds.
(Bobra and Callaghan 1990) defined the five major compounds of any oil composition as
aliphatics, aromatics, asphaltenes, resins, and waxes. Interactions between aliphatics,
aromatics, asphaltenes, resins, and waxes in complex oil mixtures allow the compounds
to be maintained in a liquid-oil state.(Bobra 1991; Buist et al. 1989)
Brandvik and Daling (1998) found that the traditional blending rules based on the
hydrophilic-lipophilic-balance (HLB), which states that a dispersant should have a HLB
between 9 and 11, is not a useful tool in dispersant optimization. The concept fails to take
into account the strong molecular interactions between the surfactants, which are not
explained by this univariate concept.
Oil that is released onto the water surface will undergo rapid, dynamic changes in
both chemical composition and physical properties due to natural weathering processes.
(Payne et al. 1983). Lower molecular weight compounds (aromatics, aliphatics) that are
necessary for solvency interactions are lost due to evaporation and dissolution during
natural weathering processes. Water is rapidly incorporated into many oils to form stable
water in oil emulsions (mousse), which are characterized by substantially higher
viscosities (Payne et al. 1983). Studies by Buist and Ross (1986) and Daling (1988) have
shown that viscous mousse is more resistant to chemical dispersion than its less viscous
parent oil. Water in oil emulsions are formed rapidly in the field, making them important
for consideration in chemical dispersion. Therefore, the period of time or window of
5
opportunity during which chemical dispersants may be effectively used for an oil spill
may be relatively short.
Canevari (1982) noted that there may be two mechanisms to stabilize water in oil
emulsions: (1) actions of natural surfactants such as those addressed by Bridie et al.
(1980) and NRC (1985) and (2) the presence of bi-wetted solid particles (partly water
wetted and partly oil wetted) at oil- water interfaces that prevent emulsified water
droplets in oil from coalescing with each other.
Three mechanisms have been used for dispersant applications in lab tests: (1)
premixing of a dispersant with an oil before the test begins, (2) premixing of a dispersant
with the water before the oil is introduced into the system (Rewick et al. 2005; Rewick et
al. 1984), and (3) mixing of the dispersant with oil at the oil-air interface as a part of the
testing procedure itself. This situation is most representative of the situation likely to be
encountered at sea and ensures that dilution of a dispersant into oil is more gradual.
Fingas et al. (2005a) examined the natural dispersibility of 15 different types of
oil in the laboratory using the labofina rotating flask test and the Mackay-Nadeau-
Steelman test (MNS). Both of these tests impart substantial turbulence to test solutions.
Results show that the different oils were characterized by varying degrees of natural
dispersibility that are a function of the testing procedure. The ability of chemical
dispersants to disperse petroleum products will vary as a function of the chemical and
physical properties of oil. Oils characterized by higher viscosities will usually exhibit
lower capacities for chemical dispersion. Increasing viscosity appears to reduce
dispersion of oil droplets in two ways: first, migration of dispersant into oil-water
6
interface is retarded, and second, the energy required to shear off oil droplets from the
slick is increased (Clayton et al. 1993).
Fingas et al. (2005a) conducted studies on relationships between dispersant
effectiveness and mixing energy. The effect of dispersant type and oil type was also
considered. They found that each oil dispersant combination had a unique threshold or
onset of dispersion. The effectiveness increased linearly with mixing energy, expressed
as rotation speed. It was observed that effectiveness rises rapidly to 80 to 90 percent with
increasing energy for light oils treated with chemical dispersants, heavier oils dispersed
too, but to lesser effectiveness values.
Clayton et al. (1993) has shown that the salinity of receiving waters can impact
dispersion of oil. The specific intent of dispersant formulations for marine applications is
to provide maximum dispersion at normal seawater salinity.
Lower water temperatures increase the viscosity of both the oil and the dispersant.
A higher water temperature usually increases the solubility of dispersants in water, and
also affects the spilled oil temperature. Hence an increase in temperature reduces oil
viscosity and increases dispersion. Studies by Mackay and Szeto (1981), Byford et al.
(1983), and Fingas et al. (2005b) indicated an increase in dispersion efficiency with
temperature.
There have been conflicting results in the trends of dispersant effectiveness with
both increasing and decreasing water temperature. The results of the studies performed
by Byford et al. (1983) differed from those performed by Fingas (1991).
The swirling flask Test (SFT) was introduced by the US EPA to accept dispersant
products for use as an oil spill countermeasure in 1993. It was included in the final EPA
7
regulation in September 1994. In further testing, it was seen that the test gave widely
variable results among different labs (IT corporation, 1995). The errors were attributed to
the design of the flask, which led to partial remixing when the sample was being
extracted.
Blondina et al. (1999) studied the influence of salinity on dispersant effectiveness
using a modified version of the swirling flask. The flask was modified by placing a
stopcock at the bottom of the flask to facilitate the removal of the sample without
introducing mixing in the samples. The data demonstrated that the interaction between
receiving water salinity and the ability of dispersants to enhance dispersion into the water
column can be both oil and dispersant specific.
Venosa et al. (2005) identified the various factors that lead to the variance of the
SFT, and based on that information, designed a new test to give more realistic and
reproducible results. This study also showed that for the analyses of the crude oils, the
spectrophotometer and diode array demonstrated better instrument repeatability than the
GC at low concentrations (Sorial et al. 2001). The revised protocol, known as the Baffled
Flask Test (BFT), has a 150 ml trypsinizing flask with baffles, modified by placing a
stopcock at the bottom of the flask to facilitate the removal of the sample without
disturbance. The new design provides a different type of mixing regime that is more
analogous to the mixing provided by wave action in the open sea. A round robin testing
conducted by the EPA and eight international testing labs found that the BFT
performance was significantly improved over that of the SFT with regard to
reproducibility and repeatability (Sorial et al. 2004b).
8
Toxicity tests conducted on Corexit® dispersants (Clark and Ares 2000) revealed that
toxicity estimates were significantly affected by the test variables (species, life stage,
exposure duration, and temperature). The apparently greater toxicity of the oil dispersant
combination was due to the greater exposure of aquatic organisms to the dissolved and
dispersed components of the oil. The study concluded that the toxicity of the dispersant
did not add to the toxicity of the spilled oil, and asserted that it is more important to
consider the toxicity of the oil. This study alleviated any concerns over the use of
chemical dispersants for oil spill remediation.
Sorial et al. (2004a) studied the impact of operational variables (rotational speed,
mixing time, settling time, and oil to dispersant ratio) on dispersant effectiveness. It was
found that the effectiveness of the dispersant was strongly dependent on the type of oil
and type of flask. It was observed that it was difficult to differentiate between dispersants
at higher rotation speeds. (There was no significant difference in the amount of dispersion
between 200 rpm and 250 rpm). The effect of settling time was more pronounced at 150
rpm than at any other rotation speed studied. The rotation speeds above 200 rpm and
settling times above 10 minutes did not result in any further enhancement in dispersion.
The results indicated that for the Baffled Flask, the coefficient of variation for operator
repeatability was always less than ten percent. The factors most important for dispersion
were identified as rotational speed and dispersant to oil ratio. Mixing time and settling
time were found to have minor influences on the dispersion. A revised protocol with the
following operational variables was formed:
1. Rotational speed of 200 rpm
2. Mixing time of 10 min
9
3. Settling time of 10 min
4. Dispersant: oil ratio of 1:25
Sorial et al. (2004d) conducted further experiments to test the performance of the new
protocol. Experiments were run by three operators on 18 dispersants, by both the EPA
SFT and the BFT methods. The performance of the BFT was found to surpass that of the
SFT. The results further confirmed the reproducibility of the BFT as was previously
reported. Chandrasekar (2004) studied the dispersant effectiveness on three oils under
various simulated environmental conditions, viz: temperature, weathering, salinity, and
rotation speed. It was found that for light crude oil (SLC), temperature and mixing energy
were significant factors; for medium crude oil (PBC), temperature, mixing energy and
weathering were significant; and finally, for light refined oil (2FO), only temperature was
a significant factor. Statistical analyses of the experimental data (performed separately)
revealed that certain two way interactions exist between the factors. The percent
dispersion was found to increase as flask rotational speed increased from 150 to 250 rpm.
The percent dispersion was seen to decrease as the degree of weathering of the oil
increased. The impact of weathering was most pronounced in the case of PBC. When the
temperature was increased from 5 to 22C, dispersion increased in most cases. When the
temperature was increased from 22 to 35C, dispersion declined in most cases. It was
noted that temperature played a dual role: decreasing the viscosity, which increases the
dispersion; and increasing the weathering, which decreases the dispersion. A quadratic
regression model was fit to the experimental data obtained. The terms in the relationship
10
were chosen to include both linear and parabolic effects of each variable and all the
possible two and three factor interactions.
The temperature range studied was wide enough not to depict a clear picture (5, 22,
and 35 °C). Studying the dispersion at intermediate temperatures will help better
understand the impact of temperature on dispersion. Therefore, the main purpose of the
current study is to clearly establish the temperature behavior, to determine the
relationship of viscosity with dispersion at a different temperature and to provide a
comprehensive equation that will be able to predict oil dispersal.
1.4 Research Objectives
The overall objective of this research was to develop a set of empirical data on
three oils and two dispersants to serve as an input to the ERO3S model based on variation
in dispersant effectiveness caused by changes in temperature, oil type, oil weathering,
dispersant type, rotation speed of BFT, and salinity of sea water.
The specific objectives of the project were:
• To conduct a factorial experimental design in order to determine which of the
factors such as temperature, oil type, salinity, weathering, and flask speed are
related to the effectiveness of a dispersant used in oil remediation; the main
intention is to more strongly establish temperature behavior at intermediate
temperatures within the range studied previously by Chandrasekar (2004)
• Temperatures of 10 and 16 °C will be considered.
• To determine how the viscosity of the oil and weathered oil changes over the
temperature range
• To predict dispersion values using empirical relationships
11
• To draw a correlation between the trends observed in dispersant effectiveness to
the viscosity of the oils studied under simulated conditions (temperature and
weathering).
12
1.5 References
1. Blondina, G. J., Singer, M. M., Lee, I., Ouano, M. T., Hodgins, M., Tjeerdema, R.
S., and Sowby, M. L. (1999). "Influence of Salinity on Petroleum
Accommodation by Dispersants." Spill Science & Technology Bulletin 5(2), 127-
134.
2. Bobra, M. (1991)"Water in Oil Emulsification: A physicochemical Study." In
proceedings of International Oil Spill Conference, San Diego,CA, 483-488.
3. Bobra, M., and Callaghan, S. (1990). "A Catalogue of Crude Oil and Oil Product
Properties." Environment Canada, EE-125, 542.
4. Brandvik, P., and Daling, S. (1998). "Optimisation of oil spill dispersant
composition by mixture design and response surface methods." Chemometrics
and Intellegent Laboratory systems, 42, 63-72.
5. Bridie, A. L., Wanders, T. H., Zegveld, W., and van der Heijde, H. B. (1980).
"Formation, prevention and breaking of sea water in crude oil emulsions
`chocolate mousses'." Marine Pollution Bulletin, 11(12), 343-348.
6. Buist, I., S, P., D, M., and M, C. (1989)"Laboratory Studies on the Behaviour and
Cleanup of Waxy Crude Oil Spills." In proceedings of Oil Spill Conference,
Washington, D.C, 105-113.
7. Byford, D. C., Green, P. J., and Lewis, A. (1983) "Factors Influencing the
Performance and Selection of Low-Temperature Dispersants." In proceedings of
6th Arctic Marine Oilspill Program, Edmonton, Alberta, Canada, 140-150.
13
8. Canevari, G. P. (1973). "Development of the 'next generation' chemical
dispersants." In proceedings of Joint Conference on Prevention and Control of
Oil Spills, 231-240.
9. Canevari, G. P. (1982). "The formulation of an effective demulsifier for oil spill
emulsions." Marine Pollution Bulletin, 13(2), 49-54.
10. Chandrasekar, S. (2004). "Dispersant effectiveness data for a suite of
environmental conditions," MS Thesis University of Cincinnati, Cincinnati.
11. Chandrasekar, S., Sorial, G., and Weaver, J. (2005). "Dispersant effectiveness on
three oils under various simulated environmental conditions." Environmental
Engineering Science, 22(3), 324-336.
12. Clark, J., and Ares, G. (2000). "Aquatic toxicity of two Corexit dispersants."
Chemosphere, 40, 897-906.
13. Clayton, J. R., Payne, J., and Farlow, J. (1993). Oil Spill Dispersants Mechanisms
of Action and Laboratory Tests, C.K. Smoley, Boca Raton, FL.
14. Cormack, D. B., Lynch, W. J., and Dowsett, B. D. (1986/87). "Evaluation of
Dispersant effectiveness." Oil and Chemical Pollution, 3, 87-103.
15. Daling, S. (1988). "A Study of Chemical Dispersibility of Fresh and Weathered
Crude oil." In proceedings of 11th Artic Marine Oil Spill Program, 481-499.
16. Fingas, M. F., Kyle, D. A., Holmes, J. B., and Tennyson, E. J. "The effectiveness
of dispersants: Variation with energy." 2005 International Oil Spill Conference,
2273.
14
17. Fingas, M. F., Munn, D. L., White, B., Stoodley, R. G., and Crerar, I. D.
"Laboratory testing of dispersant effectiveness: The importance of oil-to-water
ratio and settling time." 2005 International Oil Spill Conference, 4257.
18. Hoult, D. P. (1972). "Oil Spreading on the Sea." Annu. Rev. Fluid Mech., 4, 341-
368.
19. Mackay, D., and Szeto, F (1981) "The Laboratory Determination of Dispersant
Effectiveness, Method Development and Results." In proceedings of Oil Spill
Conference, 11-17.
20. Mackay, D., and Wells, P. G. (1983) "Effectiveness, behavior, and toxicity of (Oil
Spill) dispersants." In Proceedings of Oil Spill Conference, San Antonio, TX, 65-
71.
21. Nes, H. (1984). "Effectiveness of Oil dispersants: Laboratory experiments."
NTNF, Oslo, Norway.
22. NRC. (1985). "Oil in the Sea: Inputs, Fates and Effects." National Research
Council, Washington, D.C.
23. NRC. (1989a). "Using Oil Spill Dispersants on the Sea." Report of the Committee
on Effectiveness of Oil Spill Dispersants, National Academy Press, Washington,
D.C.
24. NRC. (1989b). "Using Oil Spill Dispersants on the Sea." National Research
Council, National Academy Press, Washington, D.C.
25. Payne, J., Kirstein, B. E., G.D McNabb, J., and Lambach, J. L. "Multivariate
Analysis of Petroleum Hydrocarbon Weathering in the Subartic Marine
15
Environment." In Proceedings of Oil Spill Conference, San Antonio, TX, 423-
434.
26. Rewick, R. T., Sabo, K. A., Gates, J., Smith, J. H., and McCarthy Jr, L. T. "An
evaluation of oil spill dispersant testing requirements." 2005 International Oil
Spill Conference, 2765.
27. Rewick, R. T., Sabo, K. A., and Smith, J. H. "The Drop-weight Interfacial
Tension Method for Predicting Dispersant Performance in: Oil Spill Chemical
Dispersants, Research Experience and Recommendations, ASTM STP 840."
ASTM Special Technical Publication, 94-107.
28. Sorial, G., Koran, K., and Venosa, A. "Development of a rational oill spill
dispersant effectiveness protocol." International oil Spill conference, 471-478.
29. Sorial, G., Venosa, A., and Koran, K. (2004a). "Oil spill dispersant effectiveness
protocol I: Impact of operational variables." Journal of Environmental
Engineering, 130(10), 1073-1085.
30. Sorial, G., Venosa, A., and Koran, K. (2004b). "Oil spill dispersant effectiveness
protocol II: Performance of Revised protocol." Journal of Environmental
Engineering, 130(10), 1085-1093.
31. Venosa, A. D., Sorial, G. A., Uraizee, F., Richardson, T. L., and Suidan, M. T.
"Research leading to revisions in EPA's dispersant effectiveness protocol." 2005
International Oil Spill Conference, 6987.
32. Weaver, J. (2004). "Characteristics of Spilled Oils, Fuels, and Petroleum
Products: 3a. Simulation of Oil Spills and Dispersants Under Conditions of
Uncertainty." EPA 600/R-04/120, US. EPA, Raleigh, NC.
16
Chapter 2
Experimental Materials and Methods
17
2 EXPERIMENTAL MATERIALS AND METHODS
2.1 Materials
Modified 150 mL glass baffled trypsinizing flasks with screw caps at the top and Teflon
Stopcocks placed near the bottom were used in all the experiments (see Figure 1). An
orbital shaker (Lab-Line Instruments Inc, Melrose Park, IL) with a variable speed control
unit (40-400 rpm) and an orbital diameter of 0.75 inches (2 cm) was used in order to
provide turbulence to solutions in test flasks. The shaker has a control speed dial to
provide an rpm reading on a meter within the instrument. The accuracy is within ±10%.
A Brinkmann Eppendorf repeater plus pipettor (Fisher Scientific, Pittsburgh, PA) capable
of dispensing 4 μL of dispersant and 100 μL of oil with an accuracy of 0.3% and a
precision of 0.25% was used with 100 μL and 5mL syringe tip attachments. Glassware
consisting of graduated cylinders, 125 mL separatory funnels with Teflon stopcocks,
pipettes, 50 mL crimp style amber glass vials and 50, 100 and 1000 μL gas-tight syringes
were also used.
2.1.1 Analytical Instruments
A UVmini-1240 UV-VIS Spectrophotometer (UV-VIS spec) (Shimadzu Scientific
Instruments, Inc, Wood Dale, IL) capable of measuring absorbance at 340, 370 and 400
nm was used in all the experiments to measure the dispersed oil concentration after
extraction.
18
2.1.2 Reagents
The synthetic sea water “Instant Ocean” (Aquarium Systems, Mentor, OH) was used for
all the experiments at a concentration (salinity) of 34, 20, and 10 ppt, based on an ion
composition shown in table 2.1. Three types of oil samples provided by US EPA-SLC,
PBC, and 2FO were used in the study. The dispersants used for testing of test oils were
C9500, and SPC1000.
The hydrocarbon composition and physical characteristics of the test oils can be
found in Appendix A3.
19
Figure 2.1 Baffled Flask Test Apparatus
20
Table 2.1 Major Ion Composition of “Instant Ocean” Synthetic Sea Salt
Major Ion % Total Weight Ionic Concentration at
34 ppt salinity, mg/L
Chloride 47.5 18,700
Sodium 26.3 10,400
Sulfate 6.6 2,600
Magnesium 3.2 1,200
Calcium 1.0 400
Potassium 1.0 400
Bicarbonate 0.5 200
Boron 0.015 6
Strontium 0.001 8
Solids Total 86.1 34,000
Water 13.9
Total 100.0
21
2.2 Methods
2.2.1 Weathering of oils
The three oils Prudhoe Bay Crude Oil, South Louisiana Crude Oil and Number 2 Fuel
Oil were used in the study at three levels of volatilization (weathering). The weathering
of the oil was performed by bubbling air up through 1-L graduated cylinder filled with
oil. The volume of the oil remaining in the measuring cylinder was recorded with time.
The evaporative loss was then expressed as a volume percent.
%oilvolatilizedInitial volume Final volume
Initial volume = − ×100 …… (2.1)
Prudhoe Bay and South Louisiana Crude oil were weathered at 0%, 10%, and 20%
whereas Number 2 Fuel Oil was weathered at 0%, 3.8%, and 7.6%.
2.2.2 Oil Standards Procedure:
Standard solutions of oil for calibrating the UV-visible spectrophotometer were
prepared with the specific reference oils and dispersant used for a particular set of
experimental test runs.
For control treatments with no dispersant, i.e., oil control experiments, only oil was used
to make the standard solution. Initially, Oil Alone Stock Standard was prepared. The
density of the specific reference oil (2 mL) with 18 mL DCM added was measured by
using a 1 mL gas tight syringe and the concentration of the oil solution determined.
Specific volumes of Prudhoe Bay Crude Oil-DCM stock or South Louisiana Crude Oil-
DCM stock or Number 2 Fuel Oil-DCM stock were added to 30 mL of synthetic sea
22
water in a separatory funnel and extracted thrice with DCM. The volumes that were
added are given in table 2. The final DCM volume for the combined extracts was
adjusted to 20 mL with DCM. The extracts were then transferred to a 50 mL crimp style
glass vial with a Teflon/aluminum seal. The contents of the sealed vial were mixed by
inverting several times. The vials were stored at 4 ± 2 0C until time of analysis. Prior to
any analysis, the spectrophotometer ultraviolet lamp was turned on and allowed a 30-
minute warm-up period. For treatments with oil plus dispersant, Oil plus Dispersant
Stock Standard were first prepared. The density of 2 mL specific reference oil, 80 μL of
the dispersant and 18 mL DCM was measured using a 1 mL gas tight syringe and the
concentration determined. These stock solutions were used to prepare standard solutions
as mentioned above.
Table 2.2: Six point calibration curve for three oils
Calibration points
Oil 1 2 3 4 5 6
PBC 11 20 50 100 125 150
SLC 20 50 100 150 200 300
2FO 150 200 400 600 800 1000
* All numbers indicate volume of the stock solution in µL
23
2.2.3 Dispersant Effectiveness procedure:
The experimental procedure for each of the flask test runs was as follows:
120 mL of synthetic seawater equilibrated at the desired temperature was first added to
the modified trypsinizing flask (Baffled Flask), followed sequentially by addition of oil
and dispersant. A volume of 100 μL of oil was dispensed directly onto the surface of the
synthetic sea water using an Eppendorf repeater pipettor with a 5 mL syringe tip
attachment. The dispersant was then dispensed onto the center of the oil slick by using a
100 μL syringe tip attachment set to dispense 4 μL, giving a ratio of dispersant-to-oil of
1:25. The flask was then placed on the orbital shaker and mixed for 10 minutes at the
desired rotation speed. At the end of the shaking period, the flask was removed from the
shaker and allowed to remain stationary on the bench top for 10 minutes. At the end of
the settling time, the first 2 mL of sample are drained from the stopcock and discarded;
30 mL of sample are then collected in a 50 mL measuring cylinder. The 30 mL sample
was then transferred to a 125 mL separatory funnel and extracted 3 times with fresh 5 mL
DCM. The extract was then adjusted to a final volume of 20 mL and transferred to a 50
mL crimp style glass vial with an aluminum/Teflon seal. The vials were then stored at
4±2� C until the time of analysis.
2.2.4 Sample Analysis
The experimental samples extracts and the standard solutions prepared were removed
from the cold room and allowed to equilibrate at the laboratory temperature. First, a blank
solution (DCM) was introduced. Then the standard solutions were introduced in the order
24
of increasing concentrations and the absorbance values were noted at wavelengths of 340,
370, and 400 nm. After this, the experimental samples were introduced. For the samples
that exceeded the highest calibration standard point, dilution was done. This was mostly
done in case of Prudhoe Bay Crude oil which was diluted 10 times. The sequence of
analysis was thus:
1 Solvent Blank
2 Six calibration standards for the specific test oils plus dispersant and
3 Experimental samples.
2.2.5 QA/QC Checks
Precision: Instrument precision objectives for the conducted dispersant effectiveness
tests were based on analyzing 5% of all spectrophotometric measurements in duplicate.
The acceptance criterion is based upon agreement of the four replicate samples within α
5% of their mean value. The operator precision objectives are determined by using the
relative standard deviation (RSD) for percent dispersant effectiveness based on four
replicate flasks. In case of viscosity determination, the RSD is based on three replicates
of time of travel for viscosity measurements. The acceptance criterion is based upon
RSD less than 15%
100*essEffectivenAverage
DeviationdardStanRSD = …… (2.2)
25
Accuracy:
The accuracy is determined by using a mid-point standard calibration check after every 5
experimental samples analyzed (4 experimental samples or 4 replicates + method blank)
or 4 experimental samples if a method blank is not analyzed. The acceptance criterion is
based on a percent recovery of 90-110%.
Method Detection Limit: The reporting limits (RLs) by UV-Spectrophotometer for
Alaska North Crude Oil, South Louisiana Crude Oil, and Number 2 Fuel Oil are 0.04,
0.05, and 0.09 mg/L, respectively. The RLs are the low end of the calibration curves for
the analytes. The analysis of all these oils will be measured within the calibration
concentration range. If the measured concentration of any of these oils is above the
range, the sample will be diluted, and will be again analyzed to quantify that particular oil
in the calibrated concentration range. If the measured concentration of any of these oils
is below the calibrated concentration range, the data will be reported as below detection
limits.
2.2.6 Calculation Procedures for Experimental Samples
The area under the absorbance vs. wavelength curve for the standards and experimental
samples between wavelengths 340 and 400 nm was calculated using the trapezoidal rule,
according to the following equation:
2
30)AbsAbs(
2
30)AbsAbs(Area 400370370340 +
++
= …. (2.3)
Where Abs340, Abs370, and Abs400 are the absorbance measured at wavelengths of
340, 370, and 400 nm, respectively.
26
The dispersant performance (i.e, percent of oil dispersed, or Effectiveness) based on the
ratio of oil dispersed in the test system to the total oil added to the system was determined
by:
100*Voil * oil
Dispersed Oil Total % Eff
ρ= ….. (2.4)
Where:
Total Oil Dispersed = Mass of Oil x ml30
ml120 …. (2.5)
Mass of Oil, g = Concentration of Oil x VDCM …. (2.6)
where ρoil is the density of the test oil (g/1), Voil is the volume of oil added, and VDCM is
the final volume of the DCM-extract of water sample (20 ml), and the concentration of
oil (g/l) is the area determined by
Concentration of the Oil, g/L = curven calibratio theof Slope
2.3equation by determined as Area …. (2.7)
2.2.7 Viscosity measurements
A Cannon-Fenske viscometer will be used in the study for viscosity measurements. The
sample whose viscosity is to be measured is introduced into the viscometer and the time
required for the liquid front to travel between the two timing marks on the viscometer=s
capillary tube, is noted. This procedure is repeated and a second time measurement taken
for accuracy in the reading. Then the kinematic viscosity of the test oil is calculated in
mm2/s according to the following equation:
27
Kinematic Viscosity mm2/s, = C*t .... (2.8)
Where:
C = Calibration constant of the viscometer (cSt/s),
t = Measured flow time, s.
(The calibration constant can be calculated using a liquid of known viscosity and
determining t)
Figure 2.2 Cannon-Fenske Viscometer
28
Chapter 3
Dispersant Effectiveness at 10˚C
29
3.1 Introduction In this chapter, the effect of rotation speed, weathering, and salinity on percent
dispersion of the three test oils, viz: SLC, PBC, and 2FO at a temperature of 10 ± 1 °C
has been studied. The parameters and the different levels considered are as follows:
1. Temperature – 1 Level (10 ± 1 °C)
2. Salinity – 3 Levels. (34, 20, and 10 ppt)
3. Weathering – 3 Levels. (0%, 10%, and 20% weathering)
4. Mixing speed – 3 Levels. (150, 200, and 250 rpm)
5. Dispersant – 3 Levels. (Dispersant ‘A’, ‘B’, and control ‘C’)
3.2 Dispersant Effectiveness procedure
The experimental procedure for each of the flask test runs is as follows:
120 mL of synthetic seawater equilibrated at the desired temperature was first added to
the modified trypsinizing flask (Baffled Flask), followed sequentially by addition of oil
and dispersant. A volume of 100 μL of oil was dispensed directly onto the surface of the
synthetic sea water using an Eppendorf repeater pipettor with a 5 mL syringe tip
attachment. The dispersant was then dispensed onto the center of the oil slick by using a
100 μL syringe tip attachment set to dispense 4 μL, giving a ratio of dispersant-to-oil of
1:25. The flask was then placed on the orbital shaker and mixed for 10 minutes at the
desired rotation speed. At the end of the shaking period, the flask was removed from the
shaker and allowed to remain stationary on the bench top for 10 minutes. At the end of
the settling time, the first 2 mL of sample was drained from the stopcock and discarded;
30 mL of sample was then collected in a 50 mL measuring cylinder. The 30 mL sample
was then transferred to a 125 mL separatory funnel and extracted 3 times with fresh 5 mL
30
DCM. Next, the extract was adjusted to a final volume of 20 mL and transferred to a 50
mL crimp style glass vial with an aluminum/Teflon seal. Finally, the vials were stored at
4±2� C until the time of analysis.
3.3 Sample Analysis
The experimental sample extracts and the standard solutions prepared were removed
from the cold room and allowed to equilibrate at the laboratory temperature. First, a blank
solution (DCM) was introduced. Then the standard solutions were introduced in order of
increasing concentrations and the absorbance values were noted at wavelengths of 340,
370, and 400 nm. After this, the experimental samples were introduced. For the samples
that exceeded the highest calibration standard point, dilution was performed. This was
primarily in the case of Prudhoe Bay Crude oil, which was diluted 10 times. The
sequence of analysis was thus:
1. Solvent Blank
2. Six calibration standards for the specific test oils plus dispersant and
3. Experimental samples.
3.4 Discussion
All of the data collected for dispersant effectiveness at a temperature of 10 ± 1 °C
are plotted to provide a better understanding of the effect of mixing speed, salinity, and
weathering on dispersion at this temperature. It is seen that percent dispersion increased
with increasing mixing speed in all of the cases. The effects of salinity and weathering on
the test oils (SLC, PBC, and 2FO) are shown in figures 3.1 through 3.9
31
Figure 3.1 shows the effect of salinity and weathering on the dispersion of SLC
and dispersant ‘A’ at the three salinities tested. It is seen that percent dispersion increased
from 10 ppt to 20 ppt for 0% weathered oil for the higher rotation speeds (200, 250 rpm),
but salinity did not affect dispersion significantly when it increased from 20 ppt to 34 ppt.
For SLC, the RSD values for dispersant effectiveness among the three salinities at the
three weathering levels studied at this temperature were 3.99, 4.88, and 2.60 at 150, 200,
and 250 rpm, respectively. Since our acceptance criteria for the four replicates is based on
RSD <15%, hence it can be deduced that the impact of salinity is nearly the same at the
three mixing speeds.
Figure 3.2 shows the effect of salinity and weathering on the dispersion of SLC
and dispersant ‘B’ at the three salinities tested. The results clearly demonstrated that
salinity affected dispersion at 0% weathering and 150 rpm; however, the effect of salinity
was not very significant for the other rotation speeds (200, 250 rpm). The RSD values for
dispersant effectiveness among the three salinities at the three weathering levels studied
at this temperature were 19.54, 5.46, and 3.98 at 150, 200, and 250 rpm, respectively.
Comparing the RSD of 19.54 with the other values could indicate a significant impact of
salinity at a mixing speed of 150 rpm.
Figure 3.3 shows the effect of salinity and weathering on the dispersion of SLC
and dispersant ‘C’ at the three salinities tested. The percent dispersion is very low for this
combination (control samples). Dispersion values were less than 1%; consequently, no
conclusions can be made based on the observations.
Figure 3.4 shows the effect of salinity and weathering on the dispersion of PBC
and dispersant ‘A’ at the three salinities tested. It is observed that for 0% weathered PBC
32
at 34 and 20 ppt and 150 rpm, dispersion was almost the same, but there was a drop as
the salinity reduced to 10 ppt. Also it is seen that dispersion increased as salinity
increased from 10 ppt to 34 ppt for higher rotation speeds (200, 250 rpm) at 0%
weathering. For 10% weathered PBC at higher rotation speeds (200, 250 rpm),
dispersion increased with salinity from 10 ppt to 20 ppt, whereas this increase is not
significant when salinity increased from 20 ppt to 34 ppt. For 20% weathered PBC at 150
rpm, dispersion remained the same at 10 and 20 ppt, but is higher at 34 ppt. At the higher
rotation speeds (200, 250 rpm), dispersion increased with salinity through the entire range
of 10 to 34 ppt. The RSD values for dispersant effectiveness among the three salinities at
the three weathering levels studied at this temperature were 38.15, 12.81, and 9.20 at 150,
200, and 250 rpm, respectively. Comparing the RSD of 38.15 with the other values
indicates a significant impact of salinity at a mixing speed of 150 rpm.
Figure 3.5 shows the effect of salinity and weathering on the dispersion of PBC
and dispersant ‘B’ at the three salinities tested. It is observed for 0% weathered PBC at
150 rpm that the dispersion decreased with salinity; however, at the higher rotation
speeds (200, 250 rpm), the dispersion is almost the same at 10 ppt and 20 ppt, but
increased for 34 ppt. For 10% weathered PBC, dispersion is almost the same at 10 ppt
and 20 ppt, but increased at 34 ppt for all three rotation speeds (150, 200, and 250 rpm).
For 20% weathered PBC, increased salinity (from 10 ppt to 34 ppt) caused a steady,
significant increase in dispersion. . The RSD values for dispersant effectiveness among
the three salinities at the three weathering levels studied at this temperature were 33.21,
8.04, and 7.43 at 150, 200, and 250 rpm, respectively. Comparing the RSD of 33.21 with
the other values indicates a significant impact of salinity at a mixing speed of 150 rpm.
33
Figure 3.6 shows the effect of salinity and weathering on the dispersion of PBC
and dispersant ‘C’ on the three salinities tested. The percent dispersion is very low for
this combination (control samples), less than 10%; because of this, no conclusions can be
drawn regarding weathering.
Figure 3.7 shows the effect of salinity and weathering on the dispersion of 2FO
and dispersant ‘A’ at the three salinities tested. For 0% weathered 2FO at 150 rpm, it is
seen that dispersion was nearly the same at 10 ppt and 20 ppt, but increased at 34 ppt;
however, at the higher rotation speeds (200, 250 rpm), the dispersion remained almost the
same for all three salinities. For 3.8% weathered 2FO at 250 rpm, dispersion remained
almost the same for 10 ppt and 20 ppt, but increased for 34 ppt. Overall, there is a
general decrease in dispersion with an increase in percent weathering. The RSD values
for dispersant effectiveness among the three salinities at the three weathering levels
studied at this temperature were 16.70, 14.15, and 12.41 at 150, 200, and 250 rpm,
respectively. Comparing the RSD of 16.70 with the other values could a significant
impact of salinity at a mixing speed of 150 rpm. However, since the RSD was very close
to 15% (our acceptance criteria) hence, no significant impact can be confirmed.
Figure 3.8 shows the effect of salinity and weathering on the dispersion of 2FO
and dispersant ‘B’ at the three salinities tested. For 0% weathered 2FO, it is seen that the
dispersion remained almost the same at the three salinities except for 150 rpm. For 3.8%
weathered 2FO, it is seen that dispersion remained the same at 150rpm for the three
salinities, but at the higher rotation speeds (200, 250 rpm), dispersion is almost the same
for 10 ppt and 20 ppt but showed an increase at 34 ppt. For 7.6% weathered 2FO, it is
seen that at the higher rotation speeds (200, 250 rpm), the dispersion is lower overall than
34
that observed for 0% and 3.8% weathered 2FO. It is also observed for 7.6% weathering
at 150 rpm that there is an increase in dispersion from 10 ppt to 20 ppt, with little or no
change between 20 and 34 ppt. At the higher rotation speeds (200, 250 rpm), the
dispersion is similar at 10 ppt and 20 ppt as compared to a more marked increase at 34
ppt. The RSD values for dispersant effectiveness among the three salinities at the three
weathering levels studied at this temperature were 16.61, 14.15, and 12.41 at 150, 200,
and 250 rpm respectively. Since the RSD at 150 rpm is very close to 15% (our
acceptance criteria), one can conclude that no significant impact of salinity is observed.
Figure 3.9 shows the effect of salinity and weathering on the dispersion of 2FO
and dispersant ‘C’ at the three salinities tested. The percent dispersion is low for this
combination (control samples). Salinity showed no impact for the different weathering
conditions and rotation speeds.
From the above discussion and plots, the following observations can be made:
1. Dispersant effectiveness is directly proportional to the mixing speed. As the
mixing speed increased, percent dispersion increased. The increase was very
significant when the speed increased from 150 rpm to 200 rpm, but less
significant when the speed increased from 200 rpm to 250 rpm.
2. In most of the combinations, percent dispersion decreased with an increase in
weathering.
3. Viscosity of the oil played a major role in dispersion. Light crude oil (SLC) and
refined oil (2FO) were dispersed more than the medium crude (PBC).
4. The RSD values for dispersant effectiveness among the three salinities at the three
weathering levels studied at this temperature indicate that the impact of salinity is
35
significant in most cases at 150 rpm. However it should be noted that at 150rpm,
the mixing speed does not impart enough energy to the oil to cause dispersion.
36
Dispersant Effectiveness for SLC Dispersant 'A' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
10 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
20 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 3.1 Effect of Salinity and Weathering of SLC for dispersant ‘A’
37
Dispersant Effectiveness for SLC Dispersant 'B' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
10 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
20 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 3.2 Effect of Salinity and Weathering of SLC for dispersant ‘B’
38
Dispersant Effectiveness for SLC Dispersant 'C' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
10 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
20 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 3.3 Effect of Salinity and Weathering of SLC for dispersant ‘C’
39
Dispersant Effectiveness for PBC Dispersant 'A' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
10 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
20 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 3.4 Effect of Salinity and Weathering of PBC for dispersant ‘A’
40
Dispersant Effectiveness for PBC Dispersant 'B' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
10 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
20 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 3.5 Effect of Salinity and Weathering of PBC for dispersant ‘B’
41
Dispersant Effectiveness for PBC Dispersant 'C' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
10 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
20 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 3.6 Effect of Salinity and Weathering of PBC for dispersant ‘C’
42
Dispersant Effectiveness for 2FO Dispersant 'A' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
3.8 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
7.6 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 3.7 Effect of Salinity and Weathering of 2FO for dispersant ‘A’
43
Dispersant Effectiveness for 2FO Dispersant 'B' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
3.8 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
7.6 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 3.8 Effect of Salinity and Weathering of 2FO for dispersant ‘B’
44
Dispersant Effectiveness for 2FO Dispersant 'C' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
3.8 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
7.6 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 3.9 Effect of Salinity and Weathering of 2FO for dispersant ‘C’
45
Chapter 4
Dispersant Effectiveness at 16 ˚C
46
4.1 Introduction In this chapter, the effect of rotation speed, weathering, and salinity on percent
dispersion of the three test oils viz: SLC, PBC, and 2FO at a temperature of 16 ± 1 °C
has been studied. The parameters and the different levels considered were as follows:
6. Temperature – 1 Level (16 ± 1 °C)
7. Salinity – 3 Levels. (34, 20, and 10 ppt)
8. Weathering – 3 Levels. (0%, 10%, and 20% weathering)
9. Mixing speed – 3 Levels. (150, 200, and 250 rpm)
10. Dispersant – 3 Levels. (Dispersant ‘A’, ‘B’, and control ‘C’)
4.2 Dispersant Effectiveness procedure
The experimental procedure for each of the flask test runs is as follows:
120 mL of synthetic seawater equilibrated at the desired temperature is first added to the
modified trypsinizing flask (Baffled Flask), followed sequentially by addition of oil and
dispersant. A volume of 100 μL of oil is dispensed directly onto the surface of the
synthetic sea water using an Eppendorf repeater pipettor with a 5 mL syringe tip
attachment. The dispersant is then dispensed onto the center of the oil slick by using a
100 μL syringe tip attachment set to dispense 4 μL, giving a ratio of dispersant-to-oil of
1:25. The flask is then placed on the orbital shaker and mixed for 10 minutes at the
desired rotation speed. At the end of the shaking period, the flask is removed from the
shaker and allowed to remain stationary on the bench top for 10 minutes. At the end of
the settling time, the first 2 mL of sample are drained from the stopcock and discarded;
30 mL of sample are then collected in a 50 mL measuring cylinder. The 30 mL sample is
transferred to a 125 mL separatory funnel and extracted 3 times with fresh 5 mL DCM.
47
Next, the extract is adjusted to a final volume of 20 mL and transferred to a 50 mL crimp
style glass vial with an aluminum/Teflon seal. Finally, the vials are stored at 4±2�C until
the time of analysis.
4.3 Sample Analysis
The experimental samples extracts and the standard solutions prepared were removed
from the cold room and allowed to equilibrate at the laboratory temperature. First, a blank
solution (DCM) was introduced. Then the standard solutions were introduced in the order
of increasing concentrations and the absorbance values were noted at wavelengths of 340,
370, and 400 nm. After this, the experimental samples were introduced. For the samples
that exceeded the highest calibration standard point, dilution was performed. This was
primarily done in case of Prudhoe Bay Crude oil which was diluted 10 times. The
sequence of analysis was thus:
1. Solvent Blank
2. Six calibration standards for the specific test oils plus dispersant and
3. Experimental samples.
4.4 Discussion
All of the data collected for dispersant effectiveness at a temperature of 16 ± 1 °C
are plotted to provide a better understanding of the effect of mixing speed, salinity, and
weathering on dispersion at this temperature. It is seen that percent dispersion increased
with increasing mixing speed in all the cases. The results and effects of salinity and
weathering on the test oils (SLC, PBC, and 2FO) are shown in figures 4.1 through 4.9.
48
Figure 4.1 shows the effect of salinity and weathering on the dispersion of SLC
and dispersant ‘A’ at the three salinities tested. It is seen that for 0% weathered SLC at
150 rpm, dispersion increased with salinity from 10 ppt to 34 ppt. For higher rotation
speeds (200, & 250 rpm) dispersion was almost the same at 10ppt and 20ppt, but it
increased at 34ppt. For 10% and 20% weathered SLC at 150 rpm, it is observed that
dispersion decreased from 34 ppt to 20 ppt, and increased from 20 ppt to 10 ppt. It is also
observed that dispersion decreased with increased level of weathering. The decrease was
more significant at a speed of 150 rpm, when the weathering was increased from 10% to
20%. The RSD values for dispersant effectiveness among the three salinities at the three
weathering levels studied at this temperature were 39.95, 6.66, and 3.53 at 150, 200, and
250 rpm, respectively. Since our acceptance criteria for the four replicates is based on
RSD <15%, comparing the RSD of 39.95 with the other values indicates a significant
impact of salinity at a mixing speed of 150 rpm.
Figure 4.2 shows the effect of salinity and weathering on dispersion of SLC and
dispersant ‘B’ at the three salinities tested. It is seen that for 0% weathered SLC,
dispersion was similar at 10 ppt and 20 ppt, but increased at 34 ppt for all of the three
mixing speeds tested. With higher percentages of weathering, it is seen that dispersion
increased from 34 ppt to 20 ppt and decreased from 20 ppt to 10 ppt at speeds of 150 and
200 rpm. At 250 rpm dispersion remained almost the same. It is observed that in case of
34 ppt salinity at 150 rpm, dispersion decreased significantly with increasing weathering.
At 10 ppt salinity and 150 rpm, it is seen that dispersion at 10 and 20% weathered SLC
was lower than dispersion for 0% weathered SLC. The RSD values for dispersant
effectiveness among the three salinities at the three weathering levels studied at this
49
temperature were 35.38, 6.44, and 3.91 at 150, 200, and 250 rpm, respectively.
Comparing the RSD of 35.38 with the other values indicates a significant impact of
salinity at a mixing speed of 150 rpm.
Figure 4.3 shows the effect of salinity and weathering on the dispersion of SLC
and dispersant ‘C’ at the three salinities tested. The dispersion is very low for this
combination (control samples). It is observed that the dispersion decreased slightly with
increasing weathering. No specific trend is observed with salinity.
Figure 4.4 shows the effect of salinity and weathering on the dispersion of PBC
and dispersant ‘A’ at the three salinities tested. It is seen that for 0% weathered PBC,
dispersion was almost the same at 34 and 20 ppt, but decreased at 10 ppt, for 150 and 200
rpm. For the 10% weathered PBC at 150 and 200 rpm, there was a marked increase in
dispersion at 20 ppt as compared to dispersion at both 34 and 10 ppt; however, at 250
rpm, the dispersion remained the same at all of the three salinities tested. For 20%
weathered PBC, dispersion is higher at 20 ppt than at 34 or 10 ppt for all rotation speeds.
The RSD values for dispersant effectiveness among the three salinities at the three
weathering levels studied at this temperature were 31.75, 8.56, and 4.93 at 150, 200, and
250 rpm, respectively. Comparing the RSD of 31.75 with the other values indicates a
significant impact of salinity at a mixing speed of 150 rpm.
Figure 4.5 shows the effect of salinity and weathering on the dispersion of PBC
and dispersant ‘B’ at the three salinities tested. The dispersion for 150 rpm followed a
similar trend to that which was noted for dispersant ‘A’. That is, dispersion increased
from 34 ppt to 20 ppt then decreased from 20 ppt to 10 ppt, except in the case of 20%
weathered PBC at 10 ppt, which showed a remarkable increase. For 10% weathered PBC
50
at 200 and 250 rpm, dispersion decreased from 34 ppt to 20 ppt and then increased from
20 ppt to 10 ppt. For 20% weathered PBC at 150 and 250 rpm, the dispersion was similar
at 34 and 20 ppt, and increased only at 10 ppt. On the other hand, at 200 rpm, dispersion
increased with salinity from 34 to 10 ppt. The RSD values for dispersant effectiveness
among the three salinities at the three weathering levels studied at this temperature were
44.96, 8.18, and 6.79 at 150, 200, and 250 rpm, respectively. Comparing the RSD of
44.96 with the other values indicates a significant impact of salinity at a mixing speed of
150 rpm.
Figure 4.6 shows the effect of salinity and weathering on dispersion of PBC and
dispersant ‘C’ at the three salinities tested. The dispersion was very low for this
combination (control samples). It is seen that percent dispersion remained very low at all
salinities tested; thus, the impact of salinity cannot be verified.
Figure 4.7 shows the effect of salinity and weathering on dispersion of 2FO and
dispersant ‘A’ at the three salinities tested. For 0% weathered 2FO at 150 rpm, it is seen
that dispersion increased from 10 ppt to 20 ppt and decreased at 34 ppt. At 200 rpm for
the same percent weathering, it is seen that dispersion increased with salinity from 34 ppt
to 10 ppt, and at 250 rpm, dispersion was almost the same at all three salinities. For 3.8%
weathered 2FO, dispersion was almost the same for 10 and 20 ppt with an increase at 34
ppt, with the exception of 20 ppt at 200 rpm. For 7.6% weathered 2FO at 150 rpm,
dispersion increased from 10 ppt to 20 ppt, and almost remains the same at 34 ppt. At the
higher rotation speeds (200, & 250 rpm) dispersion increased with salinity from 10 ppt to
20 ppt to 34 ppt, also at these speeds weathering seems to have an impact on dispersion.
The RSD values for dispersant effectiveness among the three salinities at the three
51
weathering levels studied at this temperature were 18.92, 13.44, and 12.18 at 150, 200,
and 250 rpm, respectively. Comparing the RSD of 18.92 with the other values indicates a
significant impact of salinity at a mixing speed of 150 rpm.
Figure 4.8 shows the effect of salinity and weathering on dispersion of 2FO and
dispersant ‘B’ at the three salinities tested. For 0% weathered 2FO at 150 rpm, it is seen
that dispersion was similar at 10 and 20 ppt but increased at 34 ppt; at 200 rpm, the
significant increase is between 20 and 34 ppt (18%); and at 250 rpm, dispersion remained
almost the same at the three salinities. For 3.8% weathered 2FO at 150 and 200 rpm,
there were no significant variations in dispersion at any of the three salinities; and at 250
rpm, dispersion is almost the same at 10 and 20 ppt but increased at 34 ppt. For 7.6%
weathered 2FO at 150 rpm, dispersion was almost the same at 10 and 20 ppt but
increased at 34 ppt; there is slightly less variation at higher rotation speeds (200, & 250
rpm). In general, dispersion for 7.6% weathered 2FO is lower than dispersion at 3.8%
2FO. The RSD values for dispersant effectiveness among the three salinities at the three
weathering levels studied at this temperature were 13.84, 13.54, and 14.35 at 150, 200,
and 250 rpm respectively. As the RSD values are less than 15% (our acceptance criteria),
it is concluded that salinity played no significant role.
Figure 4.9 shows the effect of salinity and weathering on the dispersion of 2FO
and dispersant ‘C’ at the three salinities tested. The dispersion is very low for this
combination (control samples), and no trends can be seen in the data. No specific trends
can be observed with salinity and weathering.
From the above discussion and plots the following observations can be made
52
1. Dispersant effectiveness is directly proportional to the mixing speed. As the
mixing speed increased, percent dispersion increased. The increase is very
significant when the speed increased from 150 rpm to 200 rpm, but less
significant when the speed increased from 200 rpm to 250 rpm.
2. Weathering is also an important factor in dispersion. In most of the combinations
it is observed that percent dispersion decreased with an increase in weathering.
3. Viscosity of the oil played a major role in dispersion. Light crude oil (SLC) and
refined oil (2FO) were dispersed more than the medium crude (PBC).
4. The RSD values for dispersant effectiveness among the three salinities at the three
weathering levels studied at this temperature indicate that the impact of salinity is
significant in most cases at 150 rpm. However it should be noted that at 150rpm,
the mixing speed does not impart enough energy to the oil to cause dispersion.
53
Dispersant Effectiveness for SLC Dispersant 'A' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
10 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
20 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 4.1 Effect of Salinity and Weathering of SLC for dispersant ‘A’
54
Dispersant Effectiveness for SLC Dispersant 'B' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
10 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
20 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 4.2 Effect of Salinity and Weathering of SLC for dispersant ‘B’
55
Dispersant Effectiveness for SLC Dispersant 'C' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
10 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
20 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 4.3 Effect of Salinity and Weathering of SLC for dispersant ‘C’
56
Dispersant Effectiveness for PBC Dispersant 'A' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
10 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
20 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 4.4 Effect of Salinity and Weathering of PBC for dispersant ‘A’
57
Dispersant Effectiveness for PBC Dispersant 'B' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
10 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
20 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 4.5 Effect of Salinity and Weathering of PBC for dispersant ‘B’
58
Dispersant Effectiveness for PBC Dispersant 'C' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
10 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
20 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 4.6 Effect of Salinity and Weathering of PBC for dispersant ‘C’
59
Dispersant Effectiveness for 2FO Dispersant 'A' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
3.8 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
7.6 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 4.7 Effect of Salinity and Weathering of 2FO for dispersant ‘A’
60
Dispersant Effectiveness for 2FO Dispersant 'B' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
3.8 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
7.6 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 4.8 Effect of Salinity and Weathering of 2FO for dispersant ‘B’
61
Dispersant Effectiveness for 2FO Dispersant 'C' 0% weathering
Rotation Speed rpm150 200 250
% Dis pers ion
0
20
40
60
80
100
34 ppt20 ppt10 ppt
3.8 % weathering
Rotation Speed rpm150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
7.6 % weathering
Rotation Speed rpm
150 200 250
% D
ispe
rsio
n
0
20
40
60
80
100
34 ppt20 ppt10 ppt
% D
ispe
rsio
n
Figure 4.9 Effect of Salinity and Weathering of 2FO for dispersant ‘C’
62
Chapter 5
Viscosity Determination of the Test Oils
63
5.1 Abstract
When oil is exposed to the atmosphere, it undergoes a number of physical and
chemical changes, collectively referred to as weathering. Weathering is essentially the
loss of lower weight molecular compounds, (viz: aromatics and aliphatics) due to
evaporation and dissolution. Weathering, along with temperature, tends to alter the oil
viscosity and interfere with effective dispersion of the oil. The effect of temperature and
weathering on viscosity has been studied and a correlation has been drawn for the same.
5.2 Introduction
The ability of a particular refined or crude petroleum product to be dispersed is a
function of the physical and chemical properties of that oil. Oils characterized by higher
viscosities usually exhibit lower abilities for chemical dispersion. Increasing viscosity
appears to reduce the dispersion of oil droplets in two ways (1) migration of dispersant
into oil-water interface is retarded, and (2) the energy required to shear off oil droplets
from the slick is increased (Clayton et al. 1993). Mackay and Wells (1983) noted that
there may be certain ranges of absolute viscosity (approximately 100 cP) where an
increase in viscosity may actually improve retention of dispersants by oil resulting in
enhanced dispersant performance. (Absolute viscosity in cP = kinematic viscosity in cSt
X density at that temperature). It is generally accepted that dispersants perform better for
oils with viscosities less than 2000 cSt, and essentially no dispersion will occur at
viscosities greater than 10,000 cSt. (Cormack et al.1986/87). Oil water interfacial surface
tension provides the principal resistive force to droplet formulation. Typically the surface
tension ranges from 20-30 dynes/cm for fresh oils. Oil spill dispersants may reduce this
64
value to 0.01 dyne/cm or less (Nes 1984), which facilitates the natural process of droplet
formulation. Sufficient mixing energy must be provided to deform the oil, deform the
water, and create a new surface area for the oil. For low viscosity oils, most of the mixing
energy is consumed in creating new surface area in the oil. For higher viscosity oils, a
relatively greater portion of the mixing energy is utilized in deforming the oil, meaning
less energy available for forming new surface area that result in dispersed oil droplets.
Higher oil viscosities will inhibit penetration and mixing of chemical dispersant into the
oil, leading to lower dispersion. To summarize, new surface area of oil will be higher (i.e.
resulting in more and smaller oil droplets) for low viscosity oils compared to more
viscous oils.(Clayton et al. 1993)
The main objective of this chapter was to measure the viscosity of the three oils
viz: SLC, PBC and 2FO at the three weathering conditions (0%, 10%, and 20% for SLC
and PBC, 0%, 3.8%, and 7.6% for 2FO) and the six temperatures (5, 10, 16, 22, 27, 35
°C) using a Cannon-Fenske viscometer, for studying the impact of oil viscosity on
dispersant effectiveness.
5.3 Materials and Methods A Cannon-Fenske viscometer (Fisher Scientific, Pittsburg, PA) was used in the
study for viscosity measurements. Five viscometer sizes, viz: 25, 100, 150, 300 and 400
units conforming to ASTM were used. The sample, for which viscosity was to be
measured was introduced into the viscometer, and the time required for the liquid front to
travel between the two timing marks on the viscometer’s capillary tube was noted. This
procedure was repeated and a second time measurement taken for accuracy in the
65
reading. The kinematic viscosity of the test oil was then calculated in mm2/s according to
the following equation:
Kinematic Viscosity mm2/s, = C*t .... (5.1)
Where:
C = Calibration constant of the viscometer (cSt/s) = mm2/s
t = Measured flow time, s.
(The calibration constant can be calculated using a liquid of known viscosity and
determining t)
5.4 Experimental Results The five viscometer sizes viz: 25, 100, 150, 300 and 400 units used are capable
of measuring viscosities in the range of 0.5-2, 3-15, 7-35, 50-250, and 240-1200
respectively. The calibration constants for the viscometers were calculated using a liquid
of known viscosity such as water, or oil in case of very viscous oils. The calibration
constants determined for the viscometers are listed in Table 5.1. These constants were
then used in the measurements of oil viscosities according to the above equation. The
viscosity of the 9 oils (3 test oils * 3 levels of weathering) were calculated at 6 different
temperatures (Viz: 5, 10, 16, 22, 27, and 35 °C). The data collected is listed in Table 5.2.
66
Table 5.1 Calibration constants for Viscometers Viscometer
Size Range Approx. Constant, cSt/s
units cSt
5°C 10°C 16°C 22°C 27°C 35°C
25 0.5-2 2.242* 10-3 NA 1.843*10-3 NA NA 1.918*10-3
100 3.0-15 0.01759 0.01591 0.01516 0.01512 0.01348 0.01532
150 7.0-35 0.03928 0.03023 0.03285 0.03174 0.02861 0.03064
300 50-250 0.25315 0.27502 0.18613 NA 0.21281 NA
400 240-1200 1.46645 1.28323 0.99897 1.28479 1.20480 1.04414
NA – At this temperature the viscometer was not used, hence not calibrated
Table 5.2 Viscosity measurements of oils at various temperatures Oil Viscosity (cSt) at temperature (°C)
5°C 10°C 16°C 22°C 27°C 35°C
SLC 0% 9.140 8.526 7.084 5.445 4.540 3.932
SLC 10% 19.117 12.920 11.048 8.691 6.381 5.055
SLC 20% 24.983 20.105 19.358 13.756 10.043 7.721
PBC 0% 108.517 96.166 36.296 32.548 24.969 15.717
PBC 10% 597.821 192.057 107.833 91.649 61.147 34.805
PBC 20% NA NA 325.998 248.394 144.174 66.825
2FO 0% 5.255 4.408 3.982 3.580 2.795 2.533
2FO 3.8% 5.847 5.357 4.396 3.781 3.020 2.717
2FO 7.6% 6.117 5.596 4.558 3.917 3.218 2.854
NA – At these temperatures the oils were so viscous that viscosity measurement
was not possible
5.5 Regression A correlation was established between the temperature, viscosity and weathering
to determine the effect of temperature and weathering on the viscosity of the three test
67
oils. We used Minitab R14 (2003) for obtaining the correlation. The equation takes the
form:
cb wta ∗∗= η …… (5.2)
In the logarithmic form
)log()log()log( wctba ++=η …… (5.3)
Where: η = Viscosity of the test oils,
w = % weathering of the test oils,
t = Temperature °C
Table 5.3 Parameters obtained for the three test oils Parameters
Oil Const Log W level Log temp R2 Durbin -Watson
SLC 1.47 -3.93 -0.565 93.4 1.045
PBC 3.15 -8.65 -1.26 94.2 1.665
2FO 1.04 -1.84 -0.394 91.5 1.279
Tables 5.4 through 5.6 contain data comparing the experimental values and
predicted values of viscosity as obtained from the regression. It is seen that the
correlation provides very close estimates of viscosity for all three oils (see the RPD
values in Tables 5.4-5.6). Figure 5.1 compares the experimental values to the predicted
values of viscosity for the three oils as obtained from the correlation.
68
Table 5.4 Comparison for South Louisiana Crude Oil (SLC)
Oil Weathering Temperature Viscosity
Estimated
Viscosity
%
RPD‡
SLC 0%† 5 9.1390 11.9536 23.546
SLC 0% 10 8.5251 8.0816 5.487
SLC 0% 16 7.0843 6.1987 14.288
SLC 0% 22 5.4450 5.1785 5.148
SLC 0% 27 4.5405 4.6132 1.576
SLC 0% 35 3.9319 3.9838 1.304
SLC 10%† 5 19.1161 18.0801 5.730
SLC 10% 10 12.9181 12.2236 5.682
SLC 10% 16 11.0484 9.3756 17.842
SLC 10% 22 8.6916 7.8325 10.969
SLC 10% 27 6.3812 6.9775 8.547
SLC 10% 35 5.0548 6.0256 16.112
SLC 20%† 5 24.9804 28.7144 13.004
SLC 20% 10 20.1048 19.4133 3.562
SLC 20% 16 19.3598 14.8902 30.017
SLC 20% 22 13.7562 12.4394 10.586
SLC 20% 27 10.0438 11.0815 9.364
SLC 20% 35 7.7215 9.5697 19.314
†- The weathering levels have been referred to in the model as 1, 0.9, 0.8 for 0%, 10%, 20% weathering respectively.
‡ - Relative Percent Difference (RPD) = Value Estimated
Value alExperimentValue Estimated −
69
Table 5.5 Comparison for Prudhoe Bay Crude Oil (PBC)
Oil Weathering Temperature Viscosity
Estimated
Viscosity
%
RPD
PBC 0%† 5 108.5176 185.7804 41.588
PBC 0% 10 96.1612 77.4997 24.079
PBC 0% 16 36.2994 42.8450 15.277
PBC 0% 22 32.5462 28.6748 13.501
PBC 0% 27 24.9689 22.1462 12.746
PBC 0% 35 15.7181 15.9661 1.554
PBC 10%† 5 597.8607 462.2746 29.330
PBC 10% 10 192.0437 192.8413 0.414
PBC 10% 16 107.8450 106.6105 1.158
PBC 10% 22 91.6431 71.3510 28.440
PBC 10% 27 61.1505 55.1061 10.969
PBC 10% 35 34.8017 39.7283 12.401
PBC 20%† 5 NA* 1280.8551 NA
PBC 20% 10 NA* 534.3182 NA
PBC 20% 16 325.9868 295.3929 10.357
PBC 20% 22 248.3705 197.6970 25.632
PBC 20% 27 144.1783 152.6863 5.572
PBC 20% 35 66.8190 110.0779 39.298
* NA – At these temperatures the oils were so viscous that viscosity measurement
was not possible.
†- The weathering levels have been referred to in the model as 1, 0.9, 0.8 for 0%,
10%, 20% weathering respectively.
70
Table 5.6 Comparison for No.2 Fuel Oil (2FO)
Oil Weathering Temperature Viscosity
Estimated
Viscosity
%
RPD
2FO 0%† 5 5.2546 5.8135 9.614
2FO 0% 10 4.4077 4.4247 0.384
2FO 0% 16 3.9821 3.6769 8.300
2FO 0% 22 3.5800 3.2435 10.375
2FO 0% 27 2.7954 2.9921 6.574
2FO 0% 35 2.5327 2.7014 6.244
2FO 3.8%† 5 5.8468 6.2437 6.356
2FO 3.8% 10 5.3571 4.7519 12.735
2FO 3.8% 16 4.3964 3.9489 11.332
2FO 3.8% 22 3.7810 3.4835 8.543
2FO 3.8% 27 3.0202 3.2135 6.017
2FO 3.8% 35 2.7166 2.9013 6.367
2FO 7.6%† 5 6.1166 6.7248 9.044
2FO 7.6% 10 5.5958 5.1182 9.330
2FO 7.6% 16 4.5582 4.2533 7.167
2FO 7.6% 22 3.9171 3.7520 4.402
2FO 7.6% 27 3.2179 3.4612 7.031
2FO 7.6% 35 2.8544 3.1249 8.656
†- The weathering levels have been referred to in the model as 1, 0.962, 0.934 for
0%, 3.8%, 7.6 % weathering respectively.
71
Table 5.7 shows a comparison of the viscosities estimated by the regression model for
0% weathered PBC and SLC at a temperature of 40 °C as reported in Appendix C of the
EPA Swirling Flask Test (SFT) protocol.
Table 5.7 Comparison of Model with Reported Viscosities
Oil Weathering Temperature °C Kinematic Viscosity Reported Viscosity % RPD
cSt(eqn 5.1) cSt (EPA, SFT Appendix C)
PBC 0% 40 13.5333 14.09 3.95087
SLC 0% 40 3.6714 3.582 2.43603
It can be observed that the model estimated within 4% accuracy the viscosity at 40 °C,
indicating the versatility of the model.
72
South Louisiana Crude Oil
Log (Experimental Data)
0.4 0.6 0.8 1.0 1.2 1.4 1.6
Log
( F
it D
ata)
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Log SLC Exp vs Log SLC Fit
Prudhoe Bay Crude Oil
Log (Experimental Data)1.0 1.5 2.0 2.5 3.0
Log
(Fit
Dat
a)
1.0
1.5
2.0
2.5
3.0
Log PBC Exp vs Log PBC Fit
No.2 Fuel Oil
Log(Experimental Data)
0.4 0.6 0.8 1.0
Log
(Fit
Dat
a)
0.4
0.6
0.8
1.0
Log 2FO Exp vs Log 2FO Fit
Figure 5.1 Comparisons of Viscosities of the Test Oils
73
5.6 References
1. Clayton, J. R., Payne, J., and Farlow, J. (1993). Oil Spill Dispersants
Mechanisms of Action and Laboratory Tests, C.K. Smoley, Boca Raton, FL.
2. Cormack, D. B., Lynch, W. J., and Dowsett, B. D. (1986/87). "Evaluation of
Dispersant effectiveness." Oil and Chemical Pollution, 3, 87-103.
3. Mackay, D., and Wells, P. G. (1983) "Effectiveness, behavior, and toxicity of (Oil
Spill) dispersants." In Proceedings of Oil Spill Conference, San Antonio, TX. 65-
71.
4. Nes, H. (1984). "Effectiveness of Oil dispersants: Laboratory experiments."
NTNF, Oslo, Norway.
5. Minitab. (2003). "Meet Minitab Release14." Minitab Inc., User Manual.
74
Chapter 6
Statistical Analysis of Experimental Data
75
6.1 Introduction
Data for regression can be collected in two ways, viz: observationally (where the
values of independent variables are uncontrolled) and experimentally (where the values
of the variables are controlled). It is important to note that with observational data, a
statistically significant relationship between a response and a predictor does not imply a
cause and effect relationship. It is critical to have good data, but it is essential to
minimize the number of experimental runs at the same time. To achieve this, a solid
experimental design is required. This chapter deals with the statistical analysis of the data
collected in chapters 3 and 4.
6.2 Factorial Experimental Design
The response variable for the experiments conducted was the percent
effectiveness of the dispersant. The factors and levels of each of the factors were as
follows: weathering (0, 10 and 20% for SLC and PBC; 0, 3.8 and 7.6% for 2FO),
dispersant (Corexit 9500 ('A'), SPC 1000 ('B'), and oil control (‘C’)), temperature (10,
and 16°C), flask speed (150, 200 and 250 rpm) and salinity (10, 20 and 34 ppt). Using
these levels for each of the factors, a complete factorial experiment of 2 x 3 4 runs (where
the base stands for number of levels, and the exponent stands for the number of factors;
i.e., in this study the factors are temperature at two levels, weathering, dispersant, salinity
and speed at three levels), was replicated four times for the three different oils requiring a
total of 1944 experimental runs.
76
6.3 Analysis of Variance (ANOVA)
Statistical analysis was performed separately on each of the nine oil-dispersant
combinations, i.e., three oils, with dispersants (‘A’ or ‘B’) and the oils alone. The
response of percent dispersant effectiveness to the following five factors was observed:
• Temperature
• Oil Weathering
• Salinity
• Mixing Speed
• Dispersant type
The results were subjected to analysis of variance (ANOVA) in order to quantify the
main and interaction effects of the factors considered in the study using statistical
analysis software. The response (percent dispersion) was set at 95% confidence limit. The
probability, P, is compared with α=0.05 (95% confidence limit) to evaluate the main
effects and interaction effects of factors on percent dispersion. If the P value is less than
0.05, it can be concluded that the effect is significant at 95% confidence. We used the
SAS (Statistical Analysis System, version 9.1.3) for all statistical analysis. The results of
the ANOVA revealed the number of significant factors for each oil and dispersant
combination and are listed in Table 6.1. The results of the ANOVA conducted for each
oil dispersant combination can be found in Appendix A2.
77
Table 6.1 Significant Factors for Various Oil-Dispersant Combinations for 2 Temperatures (10&16 ˚C)
Oil Oil control
Experiments
Oil + dispersant ‘A’
Experiments
Oil + dispersant
‘B’ Experiments
SLC Temperature, Rotation
speed, Weathering,
Salinity by temperature
Rotation speed, Weathering,
Temperature by Weathering
Rotation speed,
Weathering
PBC Salinity, Rotation speed,
Weathering, Salinity by
Rotation speed,
Temperature by Rotation
speed
Salinity, Temperature, Rotation
speed, Weathering, Salinity by
Temperature, Temperature by
Weathering, Temperature by
Rotation speed
Rotation speed,
Weathering
2FO Rotation speed ,
weathering
Salinity, temperature, Rotation
speed, weathering
Salinity, Rotation
speed, Weathering
6.4 Empirical Relationship
A linear regression model was fit to the experimental data collected, for each of
the nine oil-dispersant combinations. All of the factors and their interactions were
considered for the model, regardless of their significance. The model takes the following
form:
iiRiTTRiWiTTWiRiSSRiTiSST
iWWiRRiSSiWWiRRiTTisSoi
xxxxxxxx
xxxxxxxy
εββββ
ββββββββ
+++++
+++++++=
)()()()()()()()(
)()()()()()()( 222222
..(6.1)
For i= 1,…n
78
Where yi is the effectiveness value at the corresponding levels of the factors (x), β0 is the
intercept, βS is the salinity effect, βT is the temperature effect, βR is the speed effect, βW
is the oil weathering effect, βS2 is the effect of second order interaction of salinity, βR
2 is
the effect of second order interaction of rotation speed, βW2 is the effect of second order
interaction of weathering, βST is the effect of temperature by salinity interaction, βSR is the
effect of speed by salinity interaction, βTW is the effect of the weathering by temperature
interaction, and βTR is the effect of temperature by speed interaction. The factors were
entered into the equation in the following form: Salinity as 10, 20, and 34 ppt,
Temperature as 10 and 16 °C, Mixing speed as 150, 200, and 250 rpm, and Weathering
as 0, 10, and 20 for SLC and PBC and 0, 3.8, and 7.6 for 2FO. The equation contains all
main effects and second order interactions for all factors. The various β parameters for
the various oil-dispersant combinations are given in Table 6.2 together with R2 values
which indicate the linearity of the model. With the exception of oil control experiments
for SLC and 2FO, all the R2 values were very close to or more than 90%.
79
Table 6.2 Coefficients of Regression equations
No. 2 Fuel Oil South Louisiana Crude Prudhoe Bay Crude
Factor Control Dispersant A
Dispersant B Control
Dispersant A
Dispersant B Control
Dispersant A
Dispersant B
Intercept 4.026 -231.87 -279.53 -33.049 -255.46 -258.26 -16.743 -280.96 -295.77 Salinity -0.8547 -0.6296 -1.043 0.456 -0.3124 1.4288 -0.0957 1.9786 0.2292 Temperature -1.1808 0.8115 1.1074 0.7631 -1.3249 0.4411 -0.1152 -1.8738 -2.1491 Rotation speed 0.2081 2.6556 3.1858 0.2078 3.0536 2.8216 0.1603 2.8901 3.3117 Weathering -0.5994 -3.3016 -3.2888 -0.0658 1.2092 1.108 0.0491 -2.149 -1.0854 Salinity2 0.013 0.0051 0.0225 -0.0007 -0.0039 -0.0281 0.0033 -0.0233 0.0108 Rotation speed2 -0.0004 -0.0053 -0.0066 -0.0003 -0.0068 -0.0059 -0.0002 -0.0063 -0.0073 Weathering2 -0.0824 0.0006 0.1586 0.0019 -0.0143 -0.0699 0.0002 0.0351 -0.0125 Salinity* Temperature 0.0184 0.0408 -0.0247 -0.0226 0.0151 -0.0196 0.0009 -0.0591 -0.07 Salinity* Rotation 0.0003 0.0007 0.0028 0.0007 0.0021 0.0008 -0.0005 0.0007 0.0015 Temperature* Weathering 0.0722 0.1194 0.0359 -0.0031 -0.0944 0.0044 -0.0018 0.096 0.0744 Temperature* Rotation 0.0031 -0.0007 -0.0066 -0.0003 0.0076 -0.0003 0.0003 0.0141 0.0129 R2 ANOVA 0.652 0.9008 0.8993 0.8386 0.9078 0.8924 0.9457 0.943 0.9324 R2 Regression 0.6354 0.8832 0.8957 0.8184 0.9021 0.8766 0.9169 0.9383 0.9321
80
Figures 6.1 through 6.3 show a comparison of measured and estimated values of
dispersant effectiveness for the three oils.
The correlations for SLC and PBC oils provided good estimates for dispersion,
and this can be seen from the clutter of points along the 1:1 line. It is seen that for SLC
with oil control the correlation estimated slightly higher dispersion values for the higher
salinities (34 and 20 ppt) and very good estimates at the lower salinity (10 ppt).
It is observed that for 2FO with dispersant ‘A’, the values predicted by the
correlation were slightly higher than those obtained experimentally for both temperatures
studied. In the case of 2FO with dispersant ‘B’, the values are closely matched, which
was evident by the clutter of points along the 1:1 line. It is interesting to note that for 2FO
with oil control, the correlation provided a satisfactory estimate of dispersion as was
determined by the clutter of points along the 1:1 line; this correlation had the lowest R2 of
63.54%.
81
SLC 34 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
SLC 20 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
SLC 10 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
Figure 6.1 Comparison of Estimated and Experimental Dispersant Effectiveness for SLC
82
PBC 34 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
PBC 20 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
PBC 10 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
Figure 6.2 Comparison of Estimated and Experimental Dispersant Effectiveness for PBC
83
2 FO 34 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
2 FO 20 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
2 FO 10 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
Figure 6.3 Comparison of Estimated and Experimental Dispersant Effectiveness for 2FO
84
6.5 Comparison with Previous Study In this section a comparison is made with previously conducted studies on
dispersant effectiveness. The linear regression model created by Chandrasekar et al.
(2004) is used for sake of comparison. The previous study looked at dispersant
effectiveness on oil spills under various simulated conditions at three temperatures, viz: 5
°C, 22 °C and 35°C.
In the previous study a linear regression model was fit to the experimental data
obtained for each of the oil-dispersant combinations. All factor terms and their
interactions were included in the model regardless of their significance. The model takes
the following form:
iiSSiWWiTTiRRiWiSSWiSiRRSiSiTTS
iRiTTRiRiWWRiTiWWTiSSiRRiTTiWWi
xxxxxxxxxx
xxxxxxxxxxy
εβββββββββββββββ
++++++++
+++++++=
22222222 )()()()()()()()()()(
)()()()()()()()()()(0
…(6.2)
for i=1,....n
Where yi is the effectiveness value at the corresponding levels of the factors (x), β0 is the
intercept, βW is the oil weathering effect, βT is the temperature effect, βR is the speed
effect, βS is the salinity effect, βWT is the effect of the weathering by temperature
interaction, βWR is the effect of the weathering by speed interaction, βTR is the effect of
temperature by speed interaction, βTS is the effect of temperature by salinity interaction,
βRS is the effect of speed by salinity interaction, βSW is the effect of salinity by weathering
interaction, βR2
is the effect of second order interaction of speed, βT2
is the effect of
second order interaction of temperature, βW2 is the effect of second order interaction of
weathering and βS2 is the effect of second order interaction of salinity. The factors were
85
entered into the equation in the following form: Salinity as 10, 20, and 34 ppt,
Temperature as 5, 10, 16, 22, and 35 °C, Mixing speed as 150, 200, and 250 rpm, and
Weathering as 0, 10, and 20 for SLC and PBC and 0, 3.8, and 7.6 for 2FO. The equation
contains all main effects and second order interactions for all factors.
In the current study, the two temperatures studied were in between those studied
by Chandrasekhar et al. (2004) viz: 10°C, and 16 °C. The model created by
Chandrasekhar et al. was used to estimate dispersant effectiveness at the two
temperatures for this study. These estimates were compared with the experimentally
collected data in order to verify the universality of the model.
Figures 6.4 through 6.6 illustrate the comparison between experimental and
predicted values of dispersion for both studies. The comparison was made by means of
95% confidence lines on both sides of the 1:1 line. It is observed that a sizeable chunk of
data lie outside the 95% confidence line on the lower side. Subsequently, 90% confidence
lines were included for the comparison. It is seen that there are still certain outliers
beyond the 90% confidence line. In the case of SLC, it is observed that most of the
estimated data for higher rotation speeds for the current study lie just outside the 90%
confidence line. Except for PBC at 20 ppt salinity, the model gives very good estimates
for the lower mixing speed. However the model was under predicting data for higher
rotation speeds, especially 200 rpm.
In this model the authors have included all of the terms irrespective of their
significance. Although this increases the R2 for the model and reduces the errors in the
estimates, it tends to tailor the model to the particular data set and gives erroneous results
for other conditions.
86
2FO 34 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Effe
ctiv
enes
s, %
0
20
40
60
80
100
120Current StudyPrevious data(Chandrashekhar, 2004)95% Conficence90% Confidence
2FO 20ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Effe
ctiv
enes
s, %
0
20
40
60
80
100
120
Current StudyPreviousdata(Chandrashekhar, 2004)95% Confidence90% Confidence
2FO 10ppt
Experimental Dispersal Effectiveness, %0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Effe
ctiv
enes
s, %
0
20
40
60
80
100
120Current studyPrevious Data (Chandrashekar,2004)95% Confidence90% Confidence
Figure 6.4 Comparison for No.2 Fuel Oil
87
PBC 34 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Current StudyPrevious Data(Chandrashekar,2004)95% Confidence90% Confidence
PBC 20ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Current StudyPrevious Data(Chandrashekar,2004)95% Confidence90% Confidence
PBC 10ppt
Experimental Dispersal Effectiveness, %0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Current StudyPrevious Data (Chandrashekar,2004)95% Confidence90% Confidence
Figure 6.5 Comparison for Prudhoe Bay Crude Oil
88
SLC 34 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Current StudyPrevious Data (Chandrashekhar,2004)95% Confidence90% Confidence
SLC 20ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Current StudyPrevious Data (Chandrashekar,2004)95% Confidence90% Confidence
SLC 10ppt
Experimental Dispersal Effectiveness, %0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Current StudyPrevious Data, (Chandrashekar,2004)95% Confidence90% Confidence
Figure 6.6 Comparison for South Louisiana Crude Oil
89
6.6 Correlation of Dispersant Effectiveness to Oil Viscosity This section draws a correlation between dispersant effectiveness and oil viscosity
as determined by the regression model discussed in chapter 5 (equation 5.3). This
correlation uses viscosity as the dependent variable and temperature and oil weathering as
the independent variables. The correlation obtained in chapter 5 (equation 5.3) was
inserted into the regression equation discussed in section 6.4 (equation 6.1); in order to
simplify and generalize it. The main motive was to develop a correlation that was a more
general form of the equation obtained in section 6.4.
The two linear regression equations were solved simultaneously and a linear
regression model was fit to the experimental data obtained, for each of the oil-dispersant
combinations. An ANOVA analysis revealed that all the factor terms and their
interactions were significant and included in the model. The results of the ANOVA can
be found in Appendix A4. The model takes the following form:
iiRiVVRiViSSViRiSSR
iVViRRiSSiVViRRisSoi
xxxxxx
xxxxxxy
εβββ
βββββββ
++++
++++++=
)()()()()()(
)()()()()()( 222222
… (6.3)
for i=1,....n
Where yi is the effectiveness value at the corresponding levels of the factors (x), β0 is the
intercept, βS is the salinity effect, βV is the oil viscosity effect, βR is the speed effect, βS2
is the effect of second order interaction of salinity, βV2 is the effect of second order
interaction of viscosity, βR2 is the effect of second order interaction of rotation speed. βSR
is the effect of salinity by speed interaction, βSV is the effect of viscosity by salinity
90
interaction, and βVR is the effect of viscosity by rotation speed. The factors were entered
into the equation in the following form: Salinity as 10, 20, and 34 ppt, mixing speed as
150, 200, and 250 rpm, and Viscosity as estimated by equation 5.3. The equation contains
all main effects and second order interactions for all factors. The various β parameters
for the various oil-dispersant combinations are given in Table 6.3 together with R2 values
which indicate the linearity of the model. If the R2 values are compared to the R2 values
for the previous correlations (6.1), it is observed that the values dropped significantly for
the oil-control combinations; (SLC about 16%, PBC about 19% and 2FO about 6%). In
the other combinations the reduction in R2 values was not very significant (less than 5%).
The model was used to estimate dispersant effectiveness and a comparison was
made between estimated and experimentally obtained dispersion values. Figures 6.7
through 6.9 show a comparison of measured and estimated values of dispersant
effectiveness for the three oils. It is observed that the model provided very good estimates
for dispersant effectiveness.
The model was then used to estimate dispersion for the temperatures studied by
Chandrasekhar et al. (2004) viz: 5°C, 22°C, and 35 °C. These estimates were compared
with the experimentally collected data to give us an idea as to how universal is the model.
Figures 6.10 through 6.12 show the comparison of experimental and predicted values of
dispersion for both studies. The comparison was made by means of 95% confidence and
90% confidence lines on both sides of the 1:1 line. It is observed that the model was able
to estimate dispersion within 90% confidence for most of the data collected.
91
Table 6.3 Coefficients of Regression equations
No. 2 Fuel Oil South Louisiana Crude Prudhoe Bay Crude
Factor Control
Dispersant
A
Dispersant
B Control
Dispersant
A
Dispersant
B Control
Dispersant
A
Dispersant
B
Intercept -76.345 -136.25 -179.54 -10.392 -165.37 -130.67 -10.517 -206.39 -103.3
Salinity -0.2314 0.016 -1.1401 -0.411 -0.014 -0.1395 -0.0332 0.2658 -0.9119
Rotation speed 0.1216 1.3243 1.895 0.2088 2.1383 1.7582 0.0949 2.2375 1.3837
Predicted Viscosity 31.887 18.249 15.114 -0.7008 -1.4865 -0.3374 -0.0012 -0.0359 -0.0662
Salinity2 0.0081 -0.0005 0.0061 0.0004 0.0006 -0.0183 0.0022 -0.0049 0.0053
Rotation speed2 -0.0001 -0.0027 -0.0034 -0.0004 -0.0046 -0.0037 -4.37E-05 -0.0044 -0.0025
Predicted Viscosity2 -3.2699 -3.5807 -2.3226 0.0082 0.0107 -0.0235 1.20E-06 1.70E-05 1.98E-05
Rotation * Predicted
Viscosity -0.0048 0.0408 -0.0157 -0.0005 0.004 0.0019 -2.43E-05 -2.76E-05 0.0001
Salinity* Rotation 0.0009 0.0017 0.0015 0.001 0.0023 0.0045 -0.0006 0.0011 0.0041
Salinity * Predicted
Viscosity -0.0408 -0.0176 0.1635 0.0129 -0.0094 0.0107 0.0001 0.0001 0.0003
R2 ANOVA 0.9611 0.9686 0.9655 0.9661 0.9746 0.945 0.9529 0.9694 0.9753
R2 Regression 0.5792 0.8353 0.8681 0.6539 0.8027 0.8145 0.7245 0.842 0.8114
92
2 FO 34 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
2 FO 20 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
2 FO 10 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
Figure 6.7 Comparison of Estimated and Experimental dispersant effectiveness for 2FO
93
PBC 34 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
PBC 20 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
PBC 10 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
Figure 6.8 Comparison of Estimated and Experimental dispersant effectiveness for PBC
94
SLC 34 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
SLC 20 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
SLC 10 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Exp vs pred
Figure 6.9 Comparison of Estimated and Experimental dispersant effectiveness for SLC
95
2FO 34 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Effe
ctiv
enes
s, %
0
20
40
60
80
100
120Current StudyPrevious data(Chandrashekhar, 2004)95% Conficence90% Confidence
2FO 20ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Effe
ctiv
enes
s, %
0
20
40
60
80
100
120
Current StudyPreviousdata(Chandrashekhar, 2004)95% Confidence90% Confidence
2FO 10ppt
Experimental Dispersal Effectiveness, %0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Effe
ctiv
enes
s, %
0
20
40
60
80
100
120Current studyPrevious Data (Chandrashekar,2004)95% Confidence90% Confidence
Figure 6.10 Comparison for No.2 Fuel Oil
96
PBC 34 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Current StudyPrevious Data(Chandrashekar,2004)95% Confidence90% Confidence
PBC 20ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Current StudyPrevious Data(Chandrashekar,2004)95% Confidence90% Confidence
PBC 10ppt
Experimental Dispersal Effectiveness, %0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Current StudyPrevious Data (Chandrashekar,2004)95% Confidence90% Confidence
Figure 6.11 Comparison for Prudhoe Bay Crude Oil
97
SLC 34 ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Current StudyPrevious Data (Chandrashekhar,2004)95% Confidence90% Confidence
SLC 20ppt
Experimental Dispersal Effectiveness, %
0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Current StudyPrevious Data (Chandrashekar,2004)95% Confidence90% Confidence
SLC 10ppt
Experimental Dispersal Effectiveness, %0 20 40 60 80 100 120
Pre
dict
ed D
ispe
rsal
Eff
ectiv
enes
s, %
0
20
40
60
80
100
120
Current StudyPrevious Data, (Chandrashekar,2004)95% Confidence90% Confidence
Figure 6.12 Comparison for South Louisiana Crude Oil
98
6.7 References
1. Statistical Analysis System, version 9.1.3 Cary, NC, SAS Institute, 2005
2. Chandrasekar, S. (2004) “Dispersant Effectiveness Data for a Suite of
Environmental Conditions”. MS Thesis. University of Cincinnati.
99
Chapter 7
Conclusions and Recommendations
100
7.1 Conclusions In the above chapters, we looked at the effectiveness of two dispersants on three oils
under different simulated environmental conditions. A full factorial experimental design
was studied to determine the impact of salinity, temperature, mixing speed, oil type, and
oil weathering on the effectiveness of the two dispersants. All the experiments were
analyzed with analysis of variance with α = 0.05. The REG procedure was used to
perform regression analysis on the experimental data collected during the study. An
empirical relationship was drawn between oil viscosity, temperature and weathering for
the test oils. The experimental data collected in this study was verified using the
dispersion model prepared in a previous study. The correlation between oil weathering
and temperature was combined with the correlation for dispersion and simplified, in
terms of input parameters. The model was used to verify data collected in a previous
study. The experimental results obtained from this study reveal the following
1. Dispersant effectiveness is not dependent on one or two factors alone, but it also
depends on certain interactions between the factors. These interactions need not
be the same for each oil dispersant combination.
2. Dispersant effectiveness is directly proportional to the mixing speed with no
exceptions.
3. Salinity has a significant impact on dispersion at a rotation speed of 150 rpm.
However it should be noted that at a mixing speed of 150 rpm does not impart
enough energy to the oil to be dispersed.
4. Oil weathering has a significant effect on dispersion in all the oil dispersant
combinations. Percent dispersion decreases with an increase in oil weathering.
101
5. Temperature has a significant impact on dispersion for oil + dispersant ‘A’
experiments, and was not significant for most of the other oil dispersant
combinations.
6. Overall the significance of the factors can be ranked in the decreasing order as:
Mixing speed, weathering, temperature and salinity.
7. Temperature and weathering have a significant role in determining the viscosity
of the oil. The correlation developed predicted within a good accuracy the
viscosity of the oil.
8. The empirical correlation developed for the experimental data for dispersant
effectiveness predicted with good accuracy the dispersant effectiveness.
9. The model developed by Chandrasekhar (2004) estimated data collected in this
study at a little less than 90% confidence.
10. The model developed in this study, for accounting oil viscosity estimated data
collected by Chandrasekhar (2004) between 90 – 95 % confidence limits.
11. This study has successfully collected empirical data and developed correlations
which have the potential to serve as input for the ERO3S model.
7.2 Recommendations
The effect of various environmental factors such as mixing energy, weathering,
temperature and salinity on the effectiveness of two dispersants has been studied in detail
in this project. In all the experiments conducted, all these factors were studied at three
varying levels. In order to better predict the behavior of dispersants, more levels in each
102
of these factors could be considered and incorporated in the factorial experimental
design.
Experiments need to be conducted at temperature of 27 ˚C in order to have a
better understanding of the temperature dependence of dispersant effectiveness between
22˚C and 35 ˚C since it was noted that there was a drop in dispersant effectiveness at 35
˚C.
It is worthwhile to conduct a study for estimating the dispersibility of a synthetic
mixture of the crude oil that contains a mixture of selected alkanes, and polyaromatic
hydrocarbons (PAH’s) that are common in the three oils studied. This will help to
determine if the dispersibility of the synthetic oil can be predicted from the dispersibility
of its different components.
103
Appendix A1
Experimental Data
104
Table A1-1 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 0% A 150 32.07 35.03 34.64 37.82 34.89 6.75
2FO 0% A 200 92.21 98.95 80.29 92.58 91.18 8.58 2FO 0% A 250 79.06 96.10 95.43 95.43 91.50 9.07
2FO 0% B 150 39.11 39.48 48.71 48.71 44.00 12.35
2FO 0% B 200 96.75 95.29 89.52 84.66 91.56 6.067
2FO 0% B 250 92.44 96.32 95.35 97.90 95.50 2.40
2FO 0% C 150 9.34 9.22 9.45 11.65 9.92 11.73
2FO 0% C 200 15.95 14.55 18.38 19.54 17.10 13.25
2FO 0% C 250 22.73 19.48 18.73 22.73 20.92 10.11
105
Table A1-2 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 0% A 150 32.07 35.03 34.64 37.82 34.89 6.75
2FO 0% A 200 89.06 83.36 90.06 90.79 88.32 3.82
2FO 0% A 250 99.67 92.75 91.96 94.09 94.62 3.68
2FO 0% B 150 32.19 40.75 29.09 37.41 34.86 14.96
2FO 0% B 200 78.95 93.29 87.94 94.14 88.58 7.87
2FO 0% B 250 89.22 97.54 96.02 99.60 95.60 4.70
2FO 0% C 150 12.00 10.03 10.32 10.90 10.81 8.05
2FO 0% C 200 19.42 18.79 19.13 16.87 18.55 6.20
2FO 0% C 250 18.61 20.47 18.96 17.97 19.00 5.56
106
Table A1-3 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 0% A 150 37.32 48.55 49.39 49.72 46.25 12.91
2FO 0% A 200 90.45 86.04 88.56 92.02 89.27 2.88
2FO 0% A 250 98.33 99.39 99.45 95.15 98.08 2.06
2FO 0% B 150 36.68 39.9 42.76 38.08 39.36 6.66 2FO 0% B 200
96.26 94.99 95.23 95.35 95.46 0.58 2FO 0% B 250 99.48 95.05 92.33 95.34 95.55 8.22 2FO 0% C 150 12.29 10.90 8.70 10.90 10.70 13.89
2FO 0% C 200 21.86 17.28 20.06 16.00 18.80 14.10
2FO 0% C 250 19.08 19.95 23.37 22.38 21.19 9.50
107
Table A1-4 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 3.8% A 150 47.18 34.65 38.29 35.38 38.87 14.80
2FO 3.8% A 200 68.51 69.57 75.23 74.64 71.99 4.77
2FO 3.8% A 250 97.49 77.86 77.12 77.63 82.53 12.09
2FO 3.8% B 150 30.32 37.34 36.15 40.53 36.19 11.90
2FO 3.8% B 200 75.98 92.42 83.45 87.54 84.85 8.19
2FO 3.8% B 250 84.20 91.37 95.80 95.70 91.77 5.94
2FO 3.8% C 150 11.60 15.73 14.74 16.13 14.56 14.05
2FO 3.8% C 200 16.33 20.55 18.56 16.08 17.88 11.74
2FO 3.8% C 250 19.70 19.21 20.85 21.94 20.42 5.97
108
Table A1-5 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 3.8% A 150 27.87 22.16 22.81 21.84 23.67 11.96
2FO 3.8% A 200 67.45 70.12 68.14 69.75 68.87 1.85
2FO 3.8% A 250 78.28 82.70 82.10 77.35 80.11 3.35
2FO 3.8% B 150 28.83 30.43 36.90 34.85 32.75 11.47
2FO 3.8% B 200 66.12 65.43 62.04 82.56 69.04 13.3
2FO 3.8% B 250 82.95 87.19 83.95 85.05 84.78 2.14
2FO 3.8% C 150 10.67 7.79 10.17 10.77 9.85 14.18
2FO 3.8% C 200 12.16 14.10 15.09 12.16 13.38 10.92
2FO 3.8% C 250 22.19 20.95 18.02 19.06 20.05 9.32
109
Table A1-6 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 3.8% A 150 41.56 39.02 40.59 40.36 40.38 2.58
2FO 3.8% A 200 80.21 75.37 77.26 77.63 77.62 2.56
2FO 3.8% A 250 84.82 98.13 94.68 87.77 91.35 6.70
2FO 3.8% B 150 32.07 33.31 34.36 32.46 33.05 3.06
2FO 3.8% B 200 92.96 84.45 90.17 88.23 88.95 4.02
2FO 3.8% B 250 96.00 95.45 99.69 93.16 96.08 2.81
2FO 3.8% C 150 11.22 13.65 12.06 12.06 12.25 8.29
2FO 3.8% C 200 18.91 19.51 18.76 16.93 18.53 6.01
2FO 3.8% C 250 21.89 22.53 19.75 20.05 21.06 6.47
110
Table A1- 7 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 7.6% A 150 32.40 39.63 36.35 30.41 34.70 11.85
2FO 7.6% A 200 68.83 67.74 68.13 62.85 66.89 4.07
2FO 7.6% A 250 67.89 67.74 69.14 70.04 68.70 1.58
2FO 7.6% B 150 29.31 37.37 28.03 32.14 31.71 13.07
2FO 7.6% B 200 74.86 59.89 54.98 65.12 63.71 13.35
2FO 7.6% B 250 76.74 72.63 70.75 72.63 73.19 3.45
2FO 7.6% C 150 9.34 9.75 11.61 9.22 9.98 11.10
2FO 7.6% C 200 15.33 17.44 13.59 15.70 15.51 10.15
2FO 7.6% C 250 16.75 18.37 15.90 15.53 16.64 7.57
111
Table A1-8 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 7.6% A 150 35.29 40.22 33.42 40.18 37.28 9.28
2FO 7.6% A 200 61.44 67.54 62.15 62.34 63.37 4.43
2FO 7.6% A 250 77.94 80.20 70.32 76.26 76.18 5.55
2FO 7.6% B 150 36.42 40.52 36.42 48.03 40.35 13.56
2FO 7.6% B 200 68.67 71.77 54.32 72.31 66.74 12.63
2FO 7.6% B 250 78.69 74.39 78.93 82.62 78.65 4.30
2FO 7.6% C 150 7.93 9.34 7.32 8.25 8.21 10.2
2FO 7.6% C 200 15.33 14.81 14.85 14.24 14.81 3.01
2FO 7.6% C 250 15.21 14.97 15.01 16.16 15.34 3.64
112
Table A1- 9 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 7.6% A 150 29.78 39.16 30.64 35.57 33.79 13.01
2FO 7.6% A 200 74.11 71.10 70.47 73.44 72.28 2.44
2FO 7.6% A 250 73.21 73.17 72.31 70.86 72.39 1.51
2FO 7.6% B 150 37.77 39.09 40.48 41.71 39.76 4.28
2FO 7.6% B 200 55.51 56.26 72.05 55.43 59.81 13.65
2FO 7.6% B 250 88.39 94.95 86.68 88.55 89.65 4.05
2FO 7.6% C 150 9.02 12.22 10.60 9.59 10.36 13.53
2FO 7.6% C 200 9.63 11.37 11.69 9.99 10.67 9.48
2FO 7.6% C 250 11.41 11.41 10.88 10.56 11.06 3.78
113
Table A1-10 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 0% A 150 53.06 41.28 45.44 54.78 48.64 13.08
SLC 0% A 200 73.59 73.06 86.92 73.93 78.87 8.72
SLC 0% A 250 96.32 91.31 83.82 93.19 91.16 5.82
SLC 0% B 150 27.65 28.32 34.08 33.31 30.84 10.77
SLC 0% B 200 88.86 88.93 85.88 86.59 87.56 1.78
SLC 0% B 250 95.64 92.66 95.35 94.19 94.46 1.43
SLC 0% C 150 0.67 0.62 0.55 0.73 0.64 12.13
SLC 0% C 200 7.40 6.41 6.71 8.47 7.25 12.58
SLC 0% C 250 10.08 9.78 9.57 11.51 10.24 8.57
114
Table A1-11 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 0% A 150 53.59 53.90 52.71 42.13 50.58 11.18
SLC 0% A 200 87.68 89.09 94.26 91.66 90.67 3.2
SLC 0% A 250 98.55 97.72 99.35 97.63 98.31 0.82
SLC 0% B 150 58.60 54.35 51.57 48.49 53.25 8.06
SLC 0% B 200 93.75 86.80 90.89 90.03 90.37 3.16
SLC 0% B 250 99.84 92.85 93.63 92.95 94.82 3.54
SLC 0% C 150 0.22 0.18 0.21 0.18 0.20 11.35
SLC 0% C 200 6.48 7.08 6.89 8.95 7.35 14.9
SLC 0% C 250 13.63 10.54 11.56 11.81 11.89 10.81
115
Table A1-12 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 0% A 150 50.34 50.79 47.81 50.43 49.84 2.75
SLC 0% A 200 87.98 89.11 91.35 92.37 90.20 2.23
SLC 0% A 250 93.12 96.68 97.19 98.89 96.47 2.51
SLC 0% B 150 62.84 62.81 68.15 60.97 63.69 4.86
SLC 0% B 200 77.29 80.85 83.80 82.11 81.01 3.41
SLC 0% B 250 96.29 94.72 99.62 98.50 97.28 2.26
SLC 0% C 150 2.10 1.78 1.60 1.52 1.75 14.78
SLC 0% C 200 7.66 5.43 6.74 7.36 6.80 14.54
SLC 0% C 250 8.82 11.21 12.16 10.14 10.58 13.57
116
Table A1-13 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 10% A 150 55.38 57.51 47.79 50.51 52.80 8.41
SLC 10% A 200 90.12 87.13 87.85 85.79 87.72 2.07
SLC 10% A 250 96.67 94.05 96.29 95.11 95.53 1.24
SLC 10% B 150 60.78 57.11 56.29 48.75 55.73 9.06
SLC 10% B 200 87.43 91.75 90.42 89.61 89.80 2.02
SLC 10% B 250 96.15 97.25 94.42 96.19 96.00 1.22
SLC 10% C 150 0.56 0.66 0.63 0.52 0.59 10.64
SLC 10% C 200 6.37 5.30 6.91 5.12 5.92 14.52
SLC 10% C 250 8.31 7.96 7.08 7.53 7.72 6.88
117
Table A1-14 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 10% A 150 43.67 51.25 46.38 46.45 46.94 6.71
SLC 10% A 200 88.58 84.28 90.03 88.23 87.78 2.80
SLC 10% A 250 95.47 95.64 95.49 91.52 94.53 2.12
SLC 10% B 150 53.70 54.70 46.41 55.26 52.52 7.85
SLC 10% B 200 90.89 89.94 91.37 94.19 91.60 1.99
SLC 10% B 250 98.75 98.80 99.43 99.67 99.16 0.46
SLC 10% C 150 0.60 0.50 0.51 0.52 0.53 9.38
SLC 10% C 200 9.29 7.12 7.20 7.64 7.81 12.96
SLC 10% C 250 14.63 14.62 12.70 12.31 13.57 9.09
118
Table A1-15 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 10% A 150 45.34 50.92 57.02 49.67 50.74 9.51
SLC 10% A 200 88.90 92.25 85.56 83.43 87.53 4.42
SLC 10% A 250 94.67 94.22 94.93 96.55 95.09 1.07
SLC 10% B 150 52.93 51.47 48.46 44.42 49.32 7.63
SLC 10% B 200 96.48 96.95 90.75 92.04 94.06 3.32
SLC 10% B 250 99.69 99.41 98.73 93.60 97.84 2.92
SLC 10% C 150 0.49 0.37 0.43 0.40 0.42 11.57
SLC 10% C 200 6.78 8.58 6.38 7.16 7.23 13.25
SLC 10% C 250 10.14 10.37 12.07 13.06 11.41 12.21
119
Table A1-16 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 20% A 150 39.87 50.74 49.19 50.53 47.58 10.90
SLC 20% A 200 84.64 87.01 87.91 91.55 87.78 3.27
SLC 20% A 250 93.85 90.65 93.28 91.24 92.25 1.68
SLC 20% B 150 44.57 37.56 43.03 49.76 43.73 11.48
SLC 20% B 200 84.55 76.32 88.75 82.82 83.11 6.21
SLC 20% B 250 92.18 85.10 92.22 92.25 90.43 3.93
SLC 20% C 150 0.30 0.32 0.25 0.25 0.28 12.80
SLC 20% C 200 6.77 4.93 6.13 5.23 5.76 14.60
SLC 20% C 250 6.99 7.21 7.13 7.72 7.26 4.39
120
Table A1-17 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 20% A 150 52.48 48.99 52.34 44.95 49.69 7.14
SLC 20% A 200 91.43 92.02 92.97 86.85 90.82 2.99
SLC 20% A 250 89.98 90.85 91.76 91.31 90.98 0.83
SLC 20% B 150 41.25 44.90 39.05 43.34 42.14 6.03
SLC 20% B 200 85.61 82.28 79.87 78.83 81.80 3.75
SLC 20% B 250 88.27 86.96 86.41 84.89 86.63 1.62
SLC 20% C 150 0.77 0.74 0.95 0.71 0.79 13.52
SLC 20% C 200 4.75 6.42 5.54 5.87 5.64 12.38
SLC 20% C 250 7.87 5.81 6.86 6.05 6.65 13.99
121
Table A1-18 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 20% A 150 52.31 45.58 42.36 47.45 46.92 8.87
SLC 20% A 200 90.54 86.17 91.35 86.92 88.75 2.91
SLC 20% A 250 96.19 90.98 95.12 94.77 94.26 2.41
SLC 20% B 150 43.27 44.79 42.64 46.41 44.28 3.80
SLC 20% B 200 85.77 83.60 85.19 79.41 83.49 3.44
SLC 20% B 250 93.26 96.08 91.86 93.27 93.62 1.89
SLC 20% C 150 0.32 0.40 0.39 0.30 0.35 14.22
SLC 20% C 200 8.95 8.65 7.97 8.18 8.44 5.29
SLC 20% C 250 9.29 11.89 10.25 12.18 10.90 12.55
122
Table A1-19 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 0% A 150 31.08 25.61 30.36 35.18 30.56 12.84
PBC 0% A 200 62.93 62.89 61.39 63.30 62.63 1.35
PBC 0% A 250 78.63 73.91 69.02 73.86 73.85 5.30
PBC 0% B 150 37.67 46.14 48.36 46.24 44.60 10.60
PBC 0% B 200 77.84 77.54 65.70 79.53 75.15 8.46
PBC 0% B 250 73.40 84.92 86.65 87.73 83.18 7.96
PBC 0% C 150 0.14 0.14 0.17 0.16 0.15 9.06
PBC 0% C 200 5.16 5.71 5.85 5.63 5.59 5.34
PBC 0% C 250 7.18 6.47 6.44 7.50 6.90 7.65
123
Table A1-20 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 0% A 150 43.66 34.87 38.14 42.80 39.87 10.34
PBC 0% A 200 70.22 70.31 70.83 69.78 70.28 0.61
PBC 0% A 250 87.40 79.97 80.93 82.84 82.78 3.98
PBC 0% B 150 40.67 32.74 39.39 37.07 37.47 9.30
PBC 0% B 200 80.30 64.64 82.56 81.68 77.30 10.98
PBC 0% B 250 86.69 87.42 85.75 85.93 86.44 0.88
PBC 0% C 150 0.13 0.14 0.11 0.12 0.12 12.37
PBC 0% C 200 5.75 5.19 4.22 5.33 5.12 12.63
PBC 0% C 250 4.99 5.41 5.72 5.99 5.53 7.75
124
Table A1- 21 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 0% A 150 41.31 46.62 37.90 34.10 39.98 13.29
PBC 0% A 200 73.37 79.99 79.22 77.51 77.52 3.8
PBC 0% A 250 85.80 88.01 82.26 87.99 86.02 3.14
PBC 0% B 150 29.86 30.00 36.18 36.38 33.11 11.08
PBC 0% B 200 80.71 82.49 90.26 84.25 84.43 4.91
PBC 0% B 250 87.86 98.81 89.62 94.69 92.74 5.36
PBC 0% C 150 0.23 0.25 0.29 0.24 0.25 10.53
PBC 0% C 200 3.37 4.17 3.59 3.14 3.57 12.34
PBC 0% C 250 5.47 5.81 7.30 5.44 6.01 14.69
125
Table A1-22 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 10% A 150 23.47 30.29 28.53 24.43 26.68 12.2
PBC 10% A 200 48.45 55.29 61.67 50.21 53.85 10.85
PBC 10% A 250 67.72 67.26 68.00 66.89 67.47 0.72
PBC 10% B 150 25.02 23.95 25.00 24.87 24.71 2.05
PBC 10% B 200 74.27 78.96 77.42 73.34 76.00 3.47
PBC 10% B 250 93.49 83.67 87.05 84.80 87.25 5.03
PBC 10% C 150 0.19 0.21 0.19 0.18 0.19 6.61
PBC 10% C 200 4.90 6.02 4.65 4.54 5.03 13.45
PBC 10% C 250 8.19 9.01 8.41 7.21 8.21 9.11
126
Table A1-23 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 10% A 150 15.52 17.95 16.64 15.94 16.44 7.05
PBC 10% A 200 54.38 68.44 58.98 70.38 63.04 12.10
PBC 10% A 250 78.12 79.60 80.40 83.23 80.41 2.53
PBC 10% B 150 25.79 22.08 25.90 18.98 23.19 14.31
PBC 10% B 200 78.24 72.75 73.31 74.11 74.60 3.33
PBC 10% B 250 84.24 89.63 84.60 84.70 85.80 2.99
PBC 10% C 150 0.25 0.27 0.19 0.24 0.24 14.76
PBC 10% C 200 4.35 4.47 4.75 4.50 4.52 3.71
PBC 10% C 250 5.96 5.56 4.50 5.27 5.32 11.56
127
Table A1- 24 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 10% A 150 22.82 20.61 18.85 18.59 20.22 9.65
PBC 10% A 200 67.33 65.36 67.90 63.14 65.93 3.26
PBC 10% A 250 81.94 82.99 82.82 77.37 81.28 3.26
PBC 10% B 150 32.91 28.66 31.55 37.08 32.55 10.75
PBC 10% B 200 83.55 76.88 75.19 78.03 78.24 4.76
PBC 10% B 250 91.68 87.86 93.39 87.97 90.23 3.05
PBC 10% C 150 0.15 0.19 0.18 0.14 0.16 12.99
PBC 10% C 200 4.27 4.15 4.42 4.23 4.27 2.65
PBC 10% C 250 6.14 5.78 5.83 5.87 5.91 2.72
128
Table A1- 25 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 20% A 150 16.69 14.98 15.65 16.53 15.96 4.99
PBC 20% A 200 54.85 54.82 54.19 55.35 54.80 0.87
PBC 20% A 250 65.61 63.39 69.99 61.12 65.03 5.82
PBC 20% B 150 12.54 10.12 10.37 12.28 11.33 11.13
PBC 20% B 200 70.04 64.95 51.75 67.63 63.59 12.84
PBC 20% B 250 69.50 71.17 74.37 75.02 72.51 3.62
PBC 20% C 150 0.38 0.36 0.38 0.34 0.36 5.00
PBC 20% C 200 7.19 5.53 5.26 5.55 5.88 14.98
PBC 20% C 250 8.00 9.06 7.11 6.75 7.73 13.36
129
Table A1- 26 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 20% A 150 13.35 13.39 15.64 15.12 14.38 8.21
PBC 20% A 200 58.66 59.21 71.27 57.15 61.57 10.60
PBC 20% A 250 73.84 84.55 75.96 71.94 76.57 7.27
PBC 20% B 150 20.47 21.56 27.99 25.14 23.79 14.46
PBC 20% B 200 60.86 80.45 66.32 63.31 67.73 12.94
PBC 20% B 250 76.78 80.30 78.50 74.07 77.41 3.42
PBC 20% C 150 0.18 0.18 0.22 0.24 0.21 14.85
PBC 20% C 200 4.95 4.40 4.36 4.84 4.64 6.50
PBC 20% C 250 6.56 6.95 8.24 8.40 7.54 12.17
130
Table A1- 27 Dispersant Effectiveness Test (Temperature = 10 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 20% A 150 29.84 32.88 29.34 31.42 30.87 5.19
PBC 20% A 200 64.87 79.50 81.21 78.48 76.02 9.88
PBC 20% A 250 85.40 91.47 80.07 66.29 80.81 13.29
PBC 20% B 150 34.35 38.57 36.65 31.19 35.19 9.02
PBC 20% B 200 71.98 71.70 69.55 82.96 74.05 8.16
PBC 20% B 250 84.40 79.00 89.37 76.06 82.21 7.16
PBC 20% C 150 0.22 0.21 0.22 0.22 0.22 2.65
PBC 20% C 200 5.89 4.68 5.02 4.85 5.11 10.51
PBC 20% C 250 6.94 7.52 7.57 8.62 7.66 9.11
131
Table A1-28 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 0% A 150 76.26 76.65 76.82 65.93 73.92 7.21
2FO 0% A 200 82.13 86.38 90.12 87.44 86.52 3.83
2FO 0% A 250 91.57 96.94 89.56 90.06 92.03 3.67
2FO 0% B 150 50.71 43.97 59.46 49.92 51.02 12.5 2FO 0% B 200 86.91 90.49 89.04 86.61 88.26 2.08 2FO 0% B 250 94.26 96.39 90.98 96.20 94.46 2.65
2FO 0% C 150 8.58 10.49 11.77 10.61 10.36 12.7
2FO 0% C 200 15.89 19.08 15.71 17.28 16.99 9.17
2FO 0% C 250 20.87 18.26 20.18 19.54 19.71 5.63
132
Table A1-29 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 0% A 150 48.22 53.64 54.03 60.34 54.05 9.17
2FO 0% A 200 89.62 98.61 90.96 96.38 93.89 4.57
2FO 0% A 250 96.49 99.90 96.32 89.45 95.54 4.58
2FO 0% B 150 29.88 34.56 29.33 31.82 31.40 7.52
2FO 0% B 200 84.66 81.99 88.85 79.44 83.74 4.8
2FO 0% B 250 98.75 96.45 99.67 99.85 98.68 1.58 2FO 0% C 150 12.52 12.41 12.12 14.50 12.89 8.43
2FO 0% C 200 19.42 20.76 19.13 22.44 20.44 7.38
2FO 0% C 250 22.85 21.05 21.34 26.38 22.90 10.7
133
Table A1-30 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 0% A 150 53.97 45.03 49.72 45.59 48.58 8.56
2FO 0% A 200 76.21 63.52 85.54 65.37 72.66 14.10
2FO 0% A 250 93.30 88.61 94.64 99.51 94.02 4.76
2FO 0% B 150 44.76 39.90 48.59 42.64 43.97 8.33
2FO 0% B 200 60.37 61.4 61.16 60.73 60.92 0.75
2FO 0% B 250 98.94 94.36 97.66 90.08 95.26 4.15
2FO 0% C 150 8.12 8.70 7.83 8.12 8.19 4.45
2FO 0% C 200 14.44 13.22 13.22 17.92 14.70 15.1
2FO 0% C 250 18.38 17.28 18.21 14.38 17.06 10.9
134
Table A1-31 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 3.8% A 150 44.46 46.35 35.75 42.62 42.29 10.9
2FO 3.8% A 200 88.50 86.71 85.42 82.47 85.77 2.96
2FO 3.8% A 250 86.80 87.17 85.00 85.05 86 1.33
2FO 3.8% B 150 43.27 38.34 31.32 43.57 39.12 14.64 2FO 3.8% B 200 68.56 77.38 66.32 70.76 70.76 6.74
2FO 3.8% B 250 78.12 72.60 69.96 84.60 76.32 8.49
2FO 3.8% C 150 13.30 12.66 12.36 14.24 13.14 6.35
2FO 3.8% C 200 17.27 14.74 17.67 14.34 16.01 10.7
2FO 3.8% C 250 24.77 24.57 26.90 21.09 24.33 9.88
135
Table A1-32 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 3.8% A 150 43.81 36.95 37.80 35.92 41.42 7.66 2FO 3.8% A 200 69.52 75.46 69.15 70.12 71.07 4.16 2FO 3.8% A 250 86.98 89.61 85.92 83.57 86.52 2.89
2FO 3.8% B 150 39.14 31.32 33.46 33.81 34.43 9.66
2FO 3.8% B 200 71.85 77.33 77.73 70.46 74.34 5.01
2FO 3.8% B 250 80.27 78.22 81.36 75.68 78.88 3.16
2FO 3.8% C 150 9.73 8.34 8.09 8.88 8.76 8.28
2FO 3.8% C 200 12.46 11.47 12.71 11.71 12.09 4.89
2FO 3.8% C 250 13.40 14.99 13.30 15.29 14.24 7.3
136
Table A1-33 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 3.8% A 150 54.41 42.66 41.97 43.35 45.60 12.9
2FO 3.8% A 200 95.74 92.28 91.50 88.96 92.12 3.04
2FO 3.8% A 250 92.19 98.04 93.76 98.59 95.64 3.3 2FO 3.8% B 150 36.10 26.59 31.32 30.27 31.07 12.67
2FO 3.8% B 200 70.41 76.38 75.93 76.38 74.78 3.9
2FO 3.8% B 250 90.57 98.09 87.24 84.75 90.16 6.43
2FO 3.8% C 150 8.39 8.34 9.23 8.19 8.54 5.52
2FO 3.8% C 200 22.19 15.73 21.64 20.95 20.13 14.8
2FO 3.8% C 250 25.07 29.68 27.35 25.36 26.86 7.94
137
Table A1-34 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 7.6% A 150 29.82 29.43 24.98 23.92 27.04 11.2
2FO 7.6% A 200 65.23 61.68 59.37 60.39 61.67 4.15
2FO 7.6% A 250 61.76 63.87 61.56 60.31 61.87 2.38
2FO 7.6% B 150 28.71 28.27 30.98 25.23 28.30 8.35
2FO 7.6% B 200 68.64 68.68 63.60 70.59 67.88 4.41
2FO 7.6% B 250 79.86 71.07 67.52 64.88 70.83 9.22
2FO 7.6% C 150 12.30 10.36 10.80 10.64 11.02 7.88
2FO 7.6% C 200 13.67 15.70 13.15 10.96 13.37 14.5
2FO 7.6% C 250 15.82 18.69 18.81 19.42 18.18 8.85
138
Table A1-35 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 7.6% A 150 53.86 47.76 55.42 42.76 49.95 11.7
2FO 7.6% A 200 65.08 66.13 63.44 64.76 64.85 1.71
2FO 7.6% A 250 75.08 94.12 77.35 82.43 82.25 10.3
2FO 7.6% B 150 42.51 41.71 39.56 30.82 38.65 13.9
2FO 7.6% B 200 73.12 58.17 57.54 60.28 62.28 11.8
2FO 7.6% B 250 74.79 60.48 60.92 60.08 64.07 11.2
2FO 7.6% C 150 7.24 7.16 7.28 6.92 7.15 2.28
2FO 7.6% C 200 10.88 11.41 13.51 11.93 11.93 9.52
2FO 7.6% C 250 15.37 16.18 15.25 13.84 15.16 6.43
139
Table A1-36 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
2FO 7.6% A 150 54.80 56.95 41.82 48.47 50.51 13.5
2FO 7.6% A 200 73.64 77.12 75.75 78.44 76.24 2.69
2FO 7.6% A 250 97.99 93.06 87.71 91.66 92.60 4.58
2FO 7.6% B 150 43.06 32.96 39.17 34.91 37.53 12
2FO 7.6% B 200 79.09 87.40 77.34 77.70 80.38 5.9
2FO 7.6% B 250 73.00 96.94 82.47 74.99 81.85 13.3
2FO 7.6% C 150 16.83 16.02 17.96 18.28 17.27 6.04
2FO 7.6% C 200 22.69 16.95 20.83 17.72 19.55 13.7
2FO 7.6% C 250 25.40 28.56 24.56 20.83 24.84 12.8
140
Table A1-37 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 0% A 150 52.74 53.57 50.89 55.01 53.05 3.24
SLC 0% A 200 84.69 81.08 83.41 81.18 82.59 2.14
SLC 0% A 250 94.55 92.20 93.78 94.26 93.7 1.12
SLC 0% B 150 58.37 58.00 58.25 57.95 58.14 0.35
SLC 0% B 200 74.7 74.77 75.41 75.07 74.99 0.43
SLC 0% B 250 89.20 87.35 89.41 88.61 88.64 1.04
SLC 0% C 150 7.08 6.43 7.30 6.91 6.93 5.32
SLC 0% C 200 9.92 10.80 10.25 9.99 10.24 3.91
SLC 0% C 250 12.67 11.91 11.19 12.60 12.09 5.71
141
Table A1-38 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 0% A 150 60.51 58.05 58.59 59.06 59.05 1.79
SLC 0% A 200 83.70 79.95 87.01 79.88 82.63 4.14
SLC 0% A 250 93.28 91.45 95.74 89.42 92.47 2.91
SLC 0% B 150 60.84 61.09 61.37 60.97 61.07 0.37
SLC 0% B 200 77.87 78.12 86.58 77.44 80.0 5.49
SLC 0% B 250 90.85 90.63 90.61 90.36 90.61 0.23
SLC 0% C 150 8.54 8.07 8.75 8.76 8.53 3.78
SLC 0% C 200 10.58 10.90 10.64 11.19 10.83 2.57
SLC 0% C 250 11.30 10.74 11.07 11.03 11.03 2.08
142
Table A1-39 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 0% A 150 47.54 36.10 42.69 50.96 44.32 14.54 SLC 0% A 200 85.84 95.20 90.55 93.90 91.37 4.57 SLC 0% A 250 98.06 99.32 98.84 99.98 99.05 0.82
SLC 0% B 150 47.54 36.10 42.69 50.96 44.32 14.54
SLC 0% B 200 86.09 92.44 86.36 92.91 89.45 4.17 SLC 0% B 250 99.48 97.99 96.91 98.99 98.34 1.16 SLC 0% C 150 1.05 0.96 1.32 1.10 1.11 1.16 SLC 0% C 200 5.21 6.06 4.65 5.29 5.30 10.91
SLC 0% C 250 9.32 8.28 8.20 7.37 8.29 9.65
143
Table A1-40 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 10% A 150 57.32 56.83 54.09 61.67 57.48 5.45
SLC 10% A 200 82.15 72.38 75.74 69.33 74.90 7.34
SLC 10% A 250 87.96 83.08 87.63 87.46 93.91 1.81
SLC 10% B 150 56.06 53.76 57.73 55.08 55.66 3.0
SLC 10% B 200 94.00 95.51 95.80 95.76 96.63 1.73
SLC 10% B 250 97.64 98.15 98.96 96.96 97.93 0.86 SLC 10% C 150
1.11 1.11 1.26 1.13 1.15 6.19 SLC 10% C 200 8.97 7.84 7.29 8.26 8.09 8.78 SLC 10% C 250
20.92 21.72 21.17 20.02 20.96 3.39
144
Table A1-41 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 10% A 150 48.38 44.58 43.07 52.51 47.14 8.96 SLC 10% A 200 90.15 90.63 93.82 91.21 91.45 1.79 SLC 10% A 250 92.04 93.40 94.15 89.93 92.38 2.01
SLC 10% B 150 60.42 65.80 66.16 57.23 62.41 6.95 SLC 10% B 200 89.51 97.04 96.63 87.93 92.85 5.19 SLC 10% B 250 99.07 99.16 97.32 95.76 97.83 1.65 SLC 10% C 150 2.31 2.89 2.53 3.15 2.72 13.72
SLC 10% C 200 11.23 10.72 13.80 11.26 11.75 11.78
SLC 10% C 250 11.76 11.58 13.29 11.52 12.04 7.00
145
Table A1-42 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 10% A 150 58.71 56.08 68.57 64.51 61.97 9.10
SLC 10% A 200 89.61 86.91 90.26 88.87 88.92 1.63 SLC 10% A 250
90.13 88.10 90.91 94.11 90.81 2.75 SLC 10% B 150 64.67 51.45 66.97 50.25 58.93 14.93 SLC 10% B 200
90.77 79.87 84.76 93.67 87.27 7.08 SLC 10% B 250
94.40 99.51 94.17 98.99 96.76 2.97 SLC 10% C 150 0.51 0.54 0.50 0.39 0.48 13.48 SLC 10% C 200 3.87 4.18 4.21 4.63 4.22 7.35 SLC 10% C 250
12.58 11.85 12.92 12.01 12.34 4.01
146
Table A1-43 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 20% A 150 27.87 28.11 28.05 27.47 27.88 1.03
SLC 20% A 200 87.80 85.06 85.30 83.73 85.47 1.99
SLC 20% A 250 91.66 92.23 90.91 93.35 92.04 1.12
SLC 20% B 150 16.82 18.21 21.59 21.48 19.52 12.24
SLC 20% B 200 86.59 87.37 87.59 86.87 87.11 0.52
SLC 20% B 250 89.72 90.48 92.24 91.46 90.98 1.21
SLC 20% C 150 0.88 0.91 1.20 0.92 0.98 15.21
SLC 20% C 200 6.15 5.34 6.20 7.21 6.23 12.27
SLC 20% C 250 15.01 15.15 15.70 15.42 15.32 1.99
147
Table A1-44 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 20% A 150 17.83 20.44 16.05 15.31 17.41 13.10
SLC 20% A 200 91.42 88.56 88.82 87.18 89.00 1.99 SLC 20% A 250
91.66 92.23 90.91 93.35 92.04 1.12 SLC 20% B 150
61.33 63.70 65.99 55.87 61.72 7.03 SLC 20% B 200 88.54 89.34 89.56 88.83 89.07 0.52 SLC 20% B 250
96.81 93.37 96.81 96.96 95.99 1.82 SLC 20% C 150 0.91 0.94 1.24 0.95 1.01 15.21 SLC 20% C 200 4.85 3.64 4.20 4.87 4.39 13.37 SLC 20% C 250
12.69 12.93 13.15 12.74 12.88 1.62
148
Table A1-45 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
SLC 20% A 150 20.77 19.32 21.28 18.88 20.07 5.70
SLC 20% A 200 85.90 92.29 92.63 89.09 89.98 3.50
SLC 20% A 250 95.85 93.25 95.62 96.00 95.18 1.36
SLC 20% B 150 22.72 17.40 21.59 19.83 20.38 11.38
SLC 20% B 200 84.34 81.07 85.60 85.23 84.06 2.45
SLC 20% B 250 96.04 96.93 97.31 97.28 96.89 0.61
SLC 20% C 150 0.89 0.98 0.88 1.05 0.95 8.40
SLC 20% C 200 5.24 4.50 4.19 5.53 4.86 12.85
SLC 20% C 250 12.31 13.49 12.26 13.03 12.77 4.64
149
Table A1-46 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 0% A 150 10.60 10.65 10.62 11.20 10.77 2.67
PBC 0% A 200 77.62 64.22 71.34 63.22 69.10 9.74
PBC 0% A 250 84.55 78.91 84.39 79.67 81.88 3.67
PBC 0% B 150 9.04 11.34 9.53 9.41 9.83 10.44 PBC 0% B 200 81.11 79.92 75.07 86.05 80.54 5.60
PBC 0% B 250 92.94 89.47 87.81 89.01 89.63 2.09
PBC 0% C 150 0.15 0.18 0.17 0.18 0.17 7.57
PBC 0% C 200 3.37 2.53 3.18 2.80 2.97 12.69
PBC 0% C 250 6.95 7.79 7.13 7.15 7.26 5.053
150
Table A1-47 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 0% A 150 20.57 21.44 23.70 20.80 21.63 6.60
PBC 0% A 200 85.35 80.21 82.58 78.56 81.68 3.61
PBC 0% A 250 87.78 85.75 81.78 86.61 85.48 3.04
PBC 0% B 150 19.10 19.68 15.09 14.93 17.20 14.77
PBC 0% B 200 81.07 68.49 84.67 74.56 77.19 9.26
PBC 0% B 250 89.85 92.40 95.22 90.14 91.90 2.70
PBC 0% C 150 0.29 0.36 0.37 0.28 0.33 14.373
PBC 0% C 200 3.15 3.36 3.34 3.14 3.25 3.60
PBC 0% C 250 6.69 5.88 4.98 5.35 5.73 12.94
151
Table A1-48 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 0% A 150 16.72 20.82 23.7 20.80 20.51 13.99
PBC 0% A 200 75.85 79.59 77.94 77.66 77.76 1.96
PBC 0% A 250 81.41 93.35 92.31 87.78 88.71 6.12
PBC 0% B 150 15.20 11.89 15.09 14.22 14.10 10.9
PBC 0% B 200 73.72 86.72 77.83 89.68 81.99 9.10
PBC 0% B 250 94.11 95.29 94.49 93.52 94.35 0.78
PBC 0% C 150 0.49 0.42 0.54 0.41 0.46 13.04
PBC 0% C 200 2.87 2.74 3.35 2.52 2.87 12.23
PBC 0% C 250 6.30 5.84 7.31 7.15 6.65 10.51
152
Table A1-49 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 10% A 150 17.72 23.27 23.59 23.85 22.13 13.31
PBC 10% A 200 60.75 56.51 67.45 74.16 64.72 11.95
PBC 10% A 250 77.72 78.66 75.49 79.15 77.75 2.08
PBC 10% B 150 30.75 23.43 29.21 30.92 28.58 12.30
PBC 10% B 200 65.03 76.36 61.68 74.40 69.37 10.26
PBC 10% B 250 90.78 88.65 84.37 80.31 86.03 5.40
PBC 10% C 150 0.4 0.36 0.34 0.32 0.35 9.55
PBC 10% C 200 2.93 3.38 2.46 2.80 2.89 13.15
PBC 10% C 250 8.53 10.55 8.69 11.06 9.71 13.27
153
Table A1-50 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 10% A 150 44.30 35.93 35.11 36.99 38.08 11.06 PBC 10% A 200 72.70 68.37 72.01 73.97 71.76 3.34 PBC 10% A 250 78.43 80.48 80.71 78.78 79.60 1.41
PBC 10% B 150 42.13 30.75 36.10 39.43 37.10 13.20 PBC 10% B 200 66.90 67.95 67.31 68.25 67.60 0.90
PBC 10% B 250 77.96 74.79 80.38 82.09 78.81 4.01
PBC 10% C 150 0.35 0.29 0.29 0.30 0.31 9.65
PBC 10% C 200 3.08 3.76 3.17 3.99 3.5 12.73
PBC 10% C 250 5.71 6.23 7.86 7.15 6.74 14.21
154
Table A1-51 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 10% A 150 31.33 31.99 36.97 25.95 31.56 14.28
PBC 10% A 200 72.76 57.68 64.44 53.03 61.98 13.84
PBC 10% A 250 84.17 86.64 72.88 73.25 79.23 9.08
PBC 10% B 150 32.34 31.42 25.61 28.50 29.47 10.34 PBC 10% B 200 72.49 79.11 67.05 64.27 70.73 9.25 PBC 10% B 250 83.38 86.69 90.37 87.86 87.08 3.33
PBC 10% C 150 0.51 0.54 0.50 0.39 0.48 13.48
PBC 10% C 200 3.22 2.52 2.53 2.48 2.69 13.32
PBC 10% C 250 7.31 8.38 6.52 6.68 7.22 11.65
155
Table A1-52 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 10 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 20% A 150 25.50 20.99 18.55 21.84 21.72 13.27 PBC 20% A 200 76.43 65.79 79.35 69.56 72.78 8.53 PBC 20% A 250 87.56 89.64 78.59 85.40 85.30 5.62
PBC 20% B 150 38.54 37.65 35.66 44.54 39.10 9.77
PBC 20% B 200 83.60 83.15 67.86 73.99 77.89 10.89
PBC 20% B 250 84.64 94.68 78.70 84.56 85.64 7.74
PBC 20% C 150 0.26 0.28 0.25 0.28 0.27 5.26
PBC 20% C 200 4.98 5.58 6.15 6.10 5.70 9.629
PBC 20% C 250 6.84 7.63 7.35 7.47 7.32 4.67
156
Table A1-53 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 20 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 20% A 150 28.27 27.67 27.25 26.36 27.39 2.93
PBC 20% A 200 65.56 72.69 82.38 81.01 75.66 9.81
PBC 20% A 250 85.77 88.44 91.12 90.34 88.92 2.67
PBC 20% B 150 19.75 19.46 19.09 14.66 18.24 13.173
PBC 20% B 200 72.25 70.58 74.94 71.01 72.19 2.71
PBC 20% B 250 79.64 68.44 83.27 80.66 78.00 8.40
PBC 20% C 150 0.28 0.25 0.24 0.30 0.27 10.24
PBC 20% C 200 4.19 3.48 3.55 3.30 3.63 10.77 PBC 20% C 250 5.18 6.94 6.56 5.66 6.08 13.32
157
Table A1-54 Dispersant Effectiveness Test (Temperature = 16 ± 1 °C, Salinity 34 ppt)
Oil Dispersant Flask
Speed
% Effectiveness of replicate samples
R1 R2 R3 R4
Average
Effectiveness
RSD
PBC 20% A 150 23.34 23.04 23.22 23.31 23.23 0.59
PBC 20% A 200 65.74 56.31 72.95 79.77 68.69 14.62
PBC 20% A 250 87.03 86.19 82.40 85.66 85.32 2.37
PBC 20% B 150 16.51 15.07 15.63 18.71 16.48 9.72
PBC 20% B 200 68.61 57.87 69.36 61.72 64.39 8.60
PBC 20% B 250 78.26 81.35 74.77 85.31 79.92 5.61
PBC 20% C 150 0.42 0.34 0.43 0.46 0.41 12.64
PBC 20% C 200 3.77 2.85 3.27 3.35 3.31 11.37
PBC 20% C 250 6.87 6.77 7.25 6.30 6.80 5.73
158
Appendix A2
Results of ANOVA
159
Table A2-1 ANOVA Results No.2 Fuel Oil and Oil Control
Source DF Type I SS Mean
Square F
value Pr>F Salinity 2 168.232675 84.116337 9.07 0.0002
Temperature 1 24.759245 24.759245 2.67 0.1039 Rotation 2 2724.251203 1362.125601 146.88 <.0001
Weathering Levels 2 238.577908 119.288954 12.86 <.0001 Salinity*Temperature 2 92.405173 46.202587 4.98 0.0077
Salinity*Rotation 4 16.904139 4.226035 0.46 0.7682 Temperature*W_Levels 2 130.758679 65.379339 7.05 0.0011 Temperature*Rotation 2 44.304456 22.152228 2.39 0.0944
Table A2-2 ANOVA Results No.2 Fuel Oil and dispersant ‘A’
Source DF Type I SS Mean
Square F
Value Pr>F Salinity 2 1667.51797 833.75899 15.74 <.0001
Temperature 1 978.47997 978.47997 18.47 <.0001 Rotation 2 83056.7286 41528.3643 784.01 <.0001
Weathering Levels 2 6333.90826 3166.95413 59.79 <.0001 Salinity*Temperature 2 492.42051 246.21026 4.65 0.0106
Salinity*Rotation 4 823.10486 205.77621 3.88 0.0046 Temperature*W_Levels 2 877.00038 438.50019 8.28 0.0004 Temperature*Rotation 2 355.75183 177.87591 3.36 0.0368
160
Table A2-3 ANOVA Results No.2 Fuel Oil and dispersant ‘B’
Source DF Type I SS Mean
Square F
Value Pr>F Salinity 2 1314.6856 657.3428 10.37 <.0001
Temperature 1 728.4587 728.4587 11.49 0.0008 Rotation 2 103400.2842 51700.1421 815.52 <.0001
Weathering Levels 2 5689.0891 2844.5446 44.87 <.0001 Salinity*Temperature 2 325.2255 162.6127 2.57 0.0795
Salinity*Rotation 4 339.3323 84.8331 1.34 0.2571 Temperature*W_Levels 2 53.9118 26.9559 0.43 0.6542 Temperature*Rotation 2 292.0502 146.0251 2.3 0.1026
Table A2-4 ANOVA Results South Louisiana Crude oil and Oil Control
Source DF Type I SS Mean
Square F
Value Pr>F Salinity 2 47.540062 23.770031 6.88 0.0013
Temperature 1 76.362338 76.362338 22.09 <.0001 Rotation 2 3163.18229 1581.591145 457.52 <.0001
Weathering Levels 2 68.503401 34.2517 9.91 <.0001 Salinity*Temperature 2 114.063303 57.031651 16.5 <.0001
Salinity*Rotation 4 24.634888 6.158722 1.78 0.134 Temperature*W_Levels 2 24.517558 12.258779 3.55 0.0307 Temperature*Rotation 2 38.002119 19.00106 5.5 0.0048
161
Table A2-5 ANOVA Results South Louisiana Crude oil and dispersant ‘A’
Source DF Type I SS Mean
Square F
Value Pr>F Salinity 2 364.38851 182.19426 3.6 0.029
Temperature 1 346.68668 346.68668 6.86 0.0095 Rotation 2 94367.98336 47183.99168 933.16 <.0001
Weathering Levels 2 1427.83236 713.91618 14.12 <.0001 Salinity*Temperature 2 70.7767 35.38835 0.7 0.4979
Salinity*Rotation 4 662.99488 165.74872 3.28 0.0125 Temperature*W_Levels 2 1170.17456 585.08728 11.57 <.0001 Temperature*Rotation 2 264.24253 132.12126 2.61 0.0758
Table A2-6 ANOVA Results South Louisiana Crude oil and dispersant ‘B’
Source DF Type I SS Mean
Square F
Value Pr>F Salinity 2 898.16611 449.08305 8.01 0.0005
Temperature 1 0.4704 0.4704 0.01 0.9271 Rotation 2 86371.61543 43185.80771 770.09 <.0001
Weathering Levels 2 3113.94111 1556.97055 27.76 <.0001 Salinity*Temperature 2 564.18637 282.09318 5.03 0.0074
Salinity*Rotation 4 1090.69487 272.67372 4.86 0.0009 Temperature*W_Levels 2 53.17734 26.58867 0.47 0.6231 Temperature*Rotation 2 27.38851 13.69425 0.24 0.7836
162
Table A2-7 ANOVA Results Prudhoe Bay Crude oil and Oil Control
Source DF Type I SS Mean
Square F
Value Pr>F Salinity 2 25.640559 12.82028 26.04 <.0001
Temperature 1 6.076912 6.076912 12.34 0.0005 Rotation 2 1596.63325 798.316625 1621.74 <.0001
Weathering Levels 2 11.635201 5.8176 11.82 <.0001 Salinity*Temperature 2 0.195937 0.097969 0.2 0.8197
Salinity*Rotation 4 23.508107 5.877027 11.94 <.0001 Temperature*W_Levels 2 3.591284 1.795642 3.65 0.0278 Temperature*Rotation 2 32.882534 16.441267 33.4 <.0001
Table A2-8 ANOVA Results Prudhoe Bay Crude oil and dispersant ‘A’
Source DF Type I SS Mean
Square F
Value Pr>F Salinity 2 2609.647 1304.8235 32.98 <.0001
Temperature 1 789.5948 789.5948 19.96 <.0001 Rotation 2 121942.652 60971.3259 1541.17 <.0001
Weathering Levels 2 1156.6174 578.3087 14.62 <.0001 Salinity*Temperature 2 888.3369 444.1685 11.23 <.0001
Salinity*Rotation 4 62.9993 15.7498 0.4 0.8099 Temperature*W_Levels 2 1292.5284 646.2642 16.34 <.0001 Temperature*Rotation 2 916.5409 458.2705 11.58 <.0001
163
Table A2-9 ANOVA Results Prudhoe Bay Crude oil and dispersant ‘B’
Source DF Type I SS Mean
Square F
Value Pr>F Salinity 2 294.8593 147.4296 2.8 0.0635
Temperature 1 206.5067 206.5067 3.92 0.0492 Rotation 2 139266.564 69633.282 1320.28 <.0001
Weathering Levels 2 2036.3668 1018.1834 19.31 <.0001 Salinity*Temperature 2 924.4896 462.2448 8.76 0.0002
Salinity*Rotation 4 110.6241 27.656 0.52 0.7179 Temperature*W_Levels 2 717.4496 358.7248 6.8 0.0014 Temperature*Rotation 2 552.1076 276.0538 5.23 0.0061
164
Appendix A3
Compositions and Physical properties of Oils
165
Table A3-1 Oil Composition – Prudhoe Bay Crude
Concentration % weight Component Weathering 0% 10% 22.50% Saturates 75 72.1 69.2 Aromatics 15 16 16.5 Resins 6.1 7.4 8.9 Asphaltenes 4 4.4 5.4 Waxes 2.6 2.9 3.3
Table A3-2 Oil Composition – South Louisiana Crude
Concentration % weight Component Weathering 0% 11% 19.70% Saturates 80.8 80.4 78.4 Aromatics 12.6 12.3 12.5 Resins 5.9 6.4 8.0 Asphaltenes 0.8 0.9 1.1 Waxes 1.7 1.8 2.0
Table A3-3 Oil Composition – No. 2 Fuel Oil
Concentration % weight Component Weathering 0% 7% 14.20% Saturates 88.2 86.1 86.1 Aromatics 10.2 11.9 11.7 Resins 1.7 2.0 2.2 Asphaltenes 0.0 0.0 0.0 Waxes 1.7 1.8 2.0
*Source- (Weaver 2004)
166
Table A3-4 Properties of test oils- SLC and PBC
Characteristic Prudhoe Bay
Crude South Louisiana
Crude
Specific Gravity* 0.894 kg/l 0.840 kg/l
API Gravity* 26.8 degrees 37.0 degrees Sulfur 1.03 % wt 0.23 % wt
Nitrogen 0.20 % wt 0.031 % wt Vanadium 21 mg/l 0.95 mg/l
Nickel 11 mg/l 1.1 mg/l Pour point 25° F 0 ° F Viscosity at 40 C 1409 cSt 3.582 cSt at 100 C 4.059 cSt 1.568 cSt
Index 210 **
* At 15 C ** Not calculable when viscosity at 100 C is less than 2.0
Table A3-5 Properties of test oil- 2FO
2FO Characteristic Maximum Minimum
API Gravity 32.1
degrees 42.8
degrees Kinematic Viscosity 100
°F 2.35 cSt 3.00 cSt Flash Point ° F -- 0 Cloud Point ° F -- 10
Sulfur % wt -- 0.35 Aniline point ° F 125 180
Carbon residue % wt -- 0.16 Aromatics % vol. 10 15
*Source - http://www.setonresourcecenter.com/cfr/40CFR/P300_090.HTM
167
Appendix A4
Results of ANOVA for Viscosity Correlation
168
Table A4-1 ANOVA Results No. 2 Fuel oil and oil control
Source DF Type I SS Mean
Square F
Value Pr > F Salinity 2 1876.28941 938.1447 443.99 <.0001 Rotation 2 2654.61641 1327.3082 628.17 <.0001
Pred Viscosity 14 13209.04705 943.50336 446.53 <.0001 Salinity* Pred Viscosity 28 1322.13728 47.21919 22.35 <.0001
Salinity*Rotation 4 65.47105 16.36776 7.75 <.0001 Rotation* Pred Viscosity 28 758.97461 27.10624 12.83 <.0001
Table A4-2 ANOVA Results No. 2 Fuel oil and dispersant ‘A’
Source DF Type I SS Mean
Square F Value Pr > F Salinity 2 6142.5106 3071.2553 157.77 <.0001 Rotation 2 156070.8083 78035.4042 4008.74 <.0001
Pred Viscosity 14 50610.5914 3615.0422 185.71 <.0001 Salinity* Pred Viscosity 28 8195.2531 292.6876 15.04 <.0001
Salinity*Rotation 4 842.0891 210.5223 10.81 <.0001 Rotation*Pred Viscosity 28 13242.8346 472.9584 24.3 <.0001
169
Table A4-3 ANOVA Results No. 2 Fuel oil and dispersant ‘B’
Source DF Type I SS Mean Square F Value Pr > F Salinity 2 2792.9025 1396.4512 60.48 <.0001 Rotation 2 194048.5526 97024.2763 4201.99 <.0001
Pred Viscosity 14 40130.1646 2866.4403 124.14 <.0001 Salinity*Pred Viscosity 28 4193.666 149.7738 6.49 <.0001
Salinity*Rotation 4 460.593 115.1482 4.99 0.0006 Rotation*Pred Viscosity 28 11992.4301 428.3011 18.55 <.0001
Table A4-4 ANOVA Results Prudhoe Bay Crude Oil and oil control
Source DF Type I SS Mean Square F Value Pr > F Salinity 2 63.848446 31.924223 60 <.0001 Rotation 2 2681.202225 1340.601113 2519.74 <.0001
Pred Viscosity 14 796.089345 56.863525 106.88 <.0001 Salinity*Pred Viscosity 28 204.604759 7.307313 13.73 <.0001
Salinity*Rotation 4 48.592904 12.148226 22.83 <.0001 Rotation*Pred Viscosity 28 297.653071 10.630467 19.98 <.0001
170
Table A4-5 ANOVA Results Prudhoe Bay Crude oil and dispersant ‘A’
Source DF Type I SS Mean
Square F Value Pr > F Salinity 2 5705.7234 2852.8617 136.67 <.0001 Rotation 2 206618.7377 103309.3688 4949.08 <.0001
Pred Viscosity 14 33924.6521 2423.1894 116.08 <.0001 Salinity*Pred Viscosity 28 6662.2386 237.9371 11.4 <.0001
Salinity*Rotation 4 895.7677 223.9419 10.73 <.0001 Rotation*Pred Viscosity 28 10184.617 363.7363 17.42 <.0001
Table A4-6 ANOVA Results Prudhoe Bay Crude oil and dispersant ‘B’
Source DF Type I SS Mean Square F Value Pr > F Salinity 2 2903.6871 1451.8436 95.92 <.0001 Rotation 2 175457.1652 87728.5826 5796.22 <.0001
Pred Viscosity 14 24409.19 1743.5136 115.19 <.0001 Salinity*Pred Viscosity 27 3091.628 114.5047 7.57 <.0001
Salinity*Rotation 4 2284.2809 571.0702 37.73 <.0001 Rotation*Pred Viscosity 28 28583.9564 1020.8556 67.45 <.0001
171
Table A4-7 ANOVA Results South Louisiana Crude Oil and oil control
Source DF Type I SS Mean
Square F Value Pr > F Salinity 2 67.537883 33.768941 42.27 <.0001 Rotation 2 3760.361543 1880.180771 2353.53 <.0001
Pred Viscosity 14 3191.722483 227.980177 285.38 <.0001 Salinity*Pred Viscosity 28 867.45972 30.980704 38.78 <.0001
Salinity*Rotation 4 88.543407 22.135852 27.71 <.0001 Rotation*Pred Viscosity 28 682.98288 24.392246 30.53 <.0001
Table A4-9 ANOVA Results South Louisiana Crude oil and dispersant ‘A’
Source DF Type I SS Mean Square F Value Pr > F Salinity 2 6807.4155 3403.7078 283.75 <.0001 Rotation 2 137595.1268 68797.5634 5735.25 <.0001
Pred Viscosity 14 19025.4116 1358.958 113.29 <.0001 Salinity*Pred Viscosity 28 3660.5897 130.7353 10.9 <.0001
Salinity*Rotation 4 760.8641 190.216 15.86 <.0001 Rotation*Pred Viscosity 28 15050.7729 537.5276 44.81 <.0001
172
Table A4-9 ANOVA Results South Louisiana Crude oil and dispersant ‘B’
Source DF Type I SS Mean Square F Value Pr > F Salinity 2 1117.5886 558.7943 23.88 <.0001 Rotation 2 129856.4301 64928.215 2775.07 <.0001
Pred Viscosity 14 13959.7332 997.1238 42.62 <.0001 Salinity*Pred Viscosity 28 3233.1394 115.4693 4.94 <.0001
Salinity*Rotation 4 3736.8032 934.2008 39.93 <.0001 Rotation*Pred Viscosity 28 7420.7199 265.0257 11.33 <.0001