1

A RESEARCH PROPOSAL ON

THE KINETICS OF DEGRADATION OF SODIUM

LAUROYLSARCOSINATE IN THE PRESENCE OF FENTON’S

REAGENT

BY

OLORUNYOMI JOSEPH FUNSO

SUPERVISOR: DR. O. OWOYOMI

SEPTEMBER, 2012

2

TABLE OF CONTENT

CONTENT PAGE

TITLE 1

ABSTRACTS 3

INTRODUCTION AND LITERATURE REVIEW 4

EXPERIMENTAL SECTION AND PROPOSED METHOD OF RESULT ANALYSIS 8

REFERENCES 18

3

ABSTRACTS

This work will be carried out in order to study the kinetics of degradation of sodium

lauroylsarcosinate in the presence of Fenton’s reagent at low pH and a temperature of 250C in

aqueous medium at predetermined times. Studies have revealed that the rate of

biodegradation of surfactants largely depends on whether the condition is aerobic or anaerobic

as some tend to be persistent under anaerobic conditions, also with the possibility of toxic by-

products being involved. However with advanced oxidation processes such Fenton’s reaction,

there is a complete oxidation of the surfactant to stable inorganic compounds. In this study, the

Fenton’s reagents will be used in varying concentrations but which are much higher than the

initial concentrations of the surfactant. To follow-up the rate of degradation, the surfactant’s

concentrations will be determined spectrophotometrically using methylene blue (a cationic

dye). The surfactant-dye interaction would have been previously studied using the methods of

continuous variation and conductometry in the premicellar regions of the surfactant in order to

determine the stoichiometry of the interaction. However, the rate law will be determined from

the degradation studies.

4

INTRODUCTION AND LITERATURE REVIEW

Surfactants have been defined as a diverse group of compounds that are designed to have

cleaning or solubilization properties (Guang-Guo, 2005; Mousavi et. al., 2011). They generally

consist of a polar head group (which may or may not be charged but is well solvated in water),

and a nonpolar hydrocarbon tail (which is not easily dissolved in water). A simple classification

of surfactants is based on the nature of the polar head. The main classes have been identified

as ionic, nonionic, amphoteric and Germini surfactants (Tadros, 2005).

All surfactants exhibit the tendency to self-associate in order to produce an aggregation

polymer called micelle at the surfactant concentration known as Critical Micelle Concentration

(CMC). For this reason, surfactants have been used to perform various functions in some

processes or products, in contrast to other organic chemicals that may be used to produce

another chemical or product (Rosen, 2004). For instance, the catalytic ability of surfactants for

some reactions has been well established (Olanrewaju et. al., 2007; Samiey and Ashoori, 2011),

surfactants are used in dispersing dyes of low solubility in the textile and printing industry

(Sabina and Span, 2000; Petra, 2004; Halide and Kartal, 2007) and the possible use of

surfactants to effect and accelerate the degradation of the toxic pollutant, Polycyclic Aromatic

Hydrocarbon has been reported (Li and Chen, 2009).

BIODEGRADATION OF SURFACTANTS

Since surfactants are used on a large-scale basis from everyday household use to industrial

cleaning and textile manufacturing, there are concerns regarding their effects, particularly their

biodegradability in the environment and their toxicity to marine organisms. The different types

of surfactants that are now in use are of different rate of biodegradation in the environment.

5

Guang-Guo (2006) noticed that while most classes of surfactants readily biodegrade under

aerobic conditions, some are persistent under anaerobic conditions. Tadros (2004) drew

attentions to the factors upon which the rate of biodegradation depends: surfactant

concentration, the pH of the environment, temperature, solubility of the surfactant in water (as

the soluble ones are more readily biodegradable than the less soluble ones which accumulate in

the lipid compartment of the organism) and the degree of branching of the alkyl chain in the

hydrophobic part of the surfactant (since extensive branching tends to reduce the rate of

biodegradation due to steric hindrance, preventing the surfactant molecule from getting close

to the active site of the enzyme).

EFFECTS OF SURFACTANTS AND THEIR BIODEGRADATION PRODUCTS ON LIVING ORGANISMS

It is a known fact that surfactants pose threat to the aquatic environment (Mehrvar and

Venhuis, 2004; Guang-Guo, 2005). Even at low concentrations, they reduce the surface tension

of water, and therefore may increase the adsorption of organic compounds such as pesticides

and phenols on the skin and membranes of aquatic animals and humans (Othman et. al., 2012).

Lee et. al., (2000) opined that in addition to the toxicity and aesthetic problems that they cause;

they also bring about the obstruction of air transportation from air to water.

Surfactants become more dangerous to aquatic lives when they biodegrade to produce harmful

intermediates and by-products. For instance, alkylphenols (nonylphenol and octylphenols)

which are degradation products of alkylphenol polyethoxylates- a class of widely used nonionic

surfactant-have been reported to have estrogenic effects and also possess the ability to

bioaccumulate in aquatic organisms in anaerobic environments(Guang-Guo, 2005). The

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eventual conversion of a surfactant into stable inorganic compounds will generally involve

several successive transformations which would depend on the conditions of the environment.

ADVANCED OXIDATION PROCESSES

The numerous factors upon which complete biodegradation of surfactants depend have led to

people to use the advanced oxidation processes which convert any organic compound to stable

inorganic compounds. Mehrvar and Venhuis (2004) discussed some advanced oxidation

techniques as follows:

a. Photocatalytic Degradation of Surfactants: This method uses a catalyst that is chemically

and biologically inert, easily recovered and reusable in the presence of ultra-violet

radiation to oxidize organic pollutants, most especially surfactants. A compound that is

normally used for this purpose is titanium (IV) oxide, TiO2. The rate of reaction is found

to be dependent on the adsorption of the surfactant on the surface of the catalyst in

addition to other optimum conditions (pH and temperature). The process has been

found to be successful in mineralization of surfactants except for the fact that takes a

long time (5 hours to degrade 80% of initial linear alkylbenzene sulphonate at

a���� =254nm). A more efficient technique is the use of hydrogen peroxide instead of

titanium (IV) oxide to oxidize surfactant.

b. Wet Air Oxidation of Surfactants: This degradation technique is suitable for the

treatment of organic or inorganic pollutants dissolved in water. It is dependent on high

temperatures and pressures operating in the range of 174–3200C and 2.17–20.7 MPa,

respectively. At high enough temperatures and pressures, the solubility of oxygen

increases and provides the driving force for oxidation. The source of oxygen is either

7

compressed air or pure oxygen. The high pressures are required to keep the water in a

liquid state. Wet Air Oxidation provides the same oxidative ability as flame combustion

but at much lower temperatures.

c. Sonochemical Oxidation of Surfactants: This technique uses high-frequency sound wave

at high temperatures and pressure to cause homolysis of water to produce radicals (H.

and OH.). The attack of the surfactant molecules by the radicals and thermal

decomposition are the main oxidation pathways. The rates of degradation depend on

the surfactant’s initial concentration.

d. Fenton’s Treatment of Surfactant: The Fenton’s system used in treating a wide variety of

organic pollutants consist of Fe2+

combined with hydrogen peroxide H2O2 under acidic

condition. It has been efficiently used as a chemical process for wastewater treatment

(Hassan et. al., 2008).The Fenton’s reagent can generate a huge amount of hydroxyl

radical with powerful oxidizing ability which attacks the organic substrate. It is highly

efficient but this depends mainly on the hydrogen peroxide concentration, Fe2+

/H2O2

ratio, pH and reaction time. When compared with other advanced oxidation methods, it

is better because its raw materials are cheaper, it does not require expensive

instrumentation and it generates a greater amount of oxidants. The widely accepted

mechanism for the reaction is as follows:

�� + � → ��� + �. + ��

�. + �� → �� + ���

�. + ������� → �������� (Hassan et. al., 2008)

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THE SCOPE OF THIS WORK

The surfactant that will be used in this study is Sodium lauroylsarcosinate (which would

thereafter be referred to as SNa)

Na+N

O

O-

O

N-lauroylsarcosine, Sodium salt

Sodium lauroylsarcosinate is a surfactant used in a wide range of personal care products such

as in the making of toothpaste and in the cosmetic industry. However, like other surfactants, it

has some environmental effects. Anwal et. al. (1983) reported its disruptive effect on the outer

membrane of Pseudomonas cepacia by altering the fluidity of the outer membrane of the

organism. The degradation of the surfactant will be carried out in the presence of Fenton’s

reagents (Fe (II)/H2O2 system) under specific conditions of pH, temperature and at

predetermined times. To monitor the rate of degradation, the surfactant concentration will be

determined spectrophometrically as earlier described by Smith (1963) and then later by Koga

et.al. (1995) and Kotchi et.al. (2010).

AIM OF THE STUDY

This work will be aimed at studying the kinetics of degradation of sodium lauroylsarcosinate in

the presence of Fenton’s reagent.

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OBJECTIVES

1. The method of continuous variation will be used to study the interaction between

methylene blue, a cationic dye with the surfactant.

2. Conductometric technique will also be used to study the surfactant-dye interaction and

this technique will be compared with the first one in order to assess the interaction.

3. Fenton’s oxidation of the surfactant will be studied and the rate law for the process will

be derived.

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EXPERIMENTAL SECTION AND PROPOSED METHOD OF RESULT ANALYSIS

In wastewater analysis and anionic surfactant degradation studies, several techniques such as

microbial sensor, amperometric biosensor, ion-pair formation with insitu flow injection analysis

using dynamic surface tension detection and chromatography have been used to determine the

surfactant content of a given reaction mixture (Pal et. al, 2005; Hassan et. al, 2008), but these

require expensive instrumentation. A simplified spectrophotometric method using

methylthioninium chloride also known as methylene blue (MBCl), a cationic dye, will be used in

the extraction and determination of residual surfactant content in the reaction mixture. This

method relies on the understanding that any surfactant molecule present forms an ion-pair

with the cationic dye and this can be extracted in a suitable organic solvent (Koga et. al., 1995;

Kotchi et. al., 2010).

NS+

N

N

Cl-

Methylthioninium chloride

Reagents: FeSO4.7H2O, H2O2 ,Methylene Blue, Sodium N-Lauroylsarcosine, Chloroform, H2SO4

and NaOH (to control the pH of the Fentons reaction)

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The Interaction between Methylene Blue (MBCl) and Sodium lauroylsarcosinate (SNa)

Two methods will be employed in studying the interaction between MBCl and SNa in order to

determine their stoichiometric composition in the ion-pair and ion-pair formation constant (Kf).

These are Job’s method of continuous variation and Conductometric technique.

Job’s Method of Continuous variation: This method was initially used to study and determine

the formula and the formation constants of transition metal complexes in solution. It was

originally described by Ostromisslenski in 1911; the principles were outlined by Denison in

1912, but the method was named after Paul Job who in 1928 published a detailed application

of the technique to study a wide range of coordination compounds. This method has been used

by researchers to study the dye-surfactant interaction in recent time (Petra and Span, 1999;

Sinem and Melda, 2003; Petra, 2004). Where only one complex is important and the measured

experimental property depends linearly on concentration, the method is capable of yielding

both the stoichiometric composition and the association constant of the complex. (Petra and

Span, 1999)

Preparation of Solutions for the Determination of Stoichiometry of the Ion-Pair: Equimolar

stock solutions of MBCl and SNa of concentrations �� and �! respectively would be prepared

in the premicellar regions of SNa such that �� = �! = 1.0 × 10�%&�'�&��,3.0 ×

10�%&�'�&��,5.0 × 10�%&�'�&��, 7.0 × 10�%&�'�&��,and 9.0 × 10�%&�'�&��.

The Critical Micelle Concentration (CMC) of SNa is 1.457 × 10�&�'�&�� (Venkataraman

and Subrahmanyam, 1985). The temperature of 250C would be maintained throughout this

study. The absorbance of the solutions of the dye would be taken in order to determine its

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molar extinction coefficient(Ɛ�). Both solutions of MBCl and SNa would be mixed in a 10 ml

flask in varying volume ratios such that 0 unit volume of SNa is added to(1 − 0) unit volume of

MBCl solution. A series of ten mixed solutions are prepared from each pair of MBCl and SNa

stock solutions. The absorbance A of the mixtures would be taken and recorded.

Determination of Stoichiometric ratio of MBCl and SNa in the Ion-Pair Formed: The

stoichiometry is determined by plotting the corrected absorbance ΔA of particular mixtures

against the volume ratio0 of the surfactant. ΔA represents the difference between the

measured absorbance Aexp and the theoretical absorbance Athe:

34 = 45�6 − 4785 (1)

The theoretical absorbance is the absorbance of the mixture if no reaction has occurred in the

solution, so that:

4785 = Ɛ9:9;(1 − <) + Ɛ=:=;< (2)

Where Ɛd and Ɛs are the molar extinction coefficients of the dye and surfactant respectively, ��

and �! are the stock concentration of the dye and surfactant respectively and 0 is the volume

ratio of the surfactant in the mixture. >?0@ represents the sum of absorbances of all species

existing in the solution.

45�6 = Ɛ9:9 + Ɛ=:= + Ɛ9=:9= (3)

Where Ɛds is the molar extinction coefficient of the dye-surfactant complex (the ion-pair) and

Cds is the concentration of the ion-pair; �! and �� are the concentrations of the free surfactant

and dye molecules respectively.

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If the absorbances are measured in the visible region of the electromagnetic spectrum where

the surfactant would show no absorption, then we could calculate the corrected absorbance as:

34 = 45�6 − Ɛ9:9;(1 − <) (4)

Studies have revealed that the plot of corrected absorbance, A> against the volume fraction of

the surfactant 0 is a curve with a maximum or minimum at 0 = 0B corresponding to the

combining ratio of the dye and surfactant in the complex (Petra and Span, 1999; Sinem and

Melda, 2003; Petra, 2004).

Determination of Equilibrium Constant of the Ion-Pair: Schaeppi-Treadwell’s Method

Schaeppi-Treadwell’s Method is a derivative of Job’s method of continuous various which will

be used in determining the ion-pair formation constant. It is a suitable method when only one

stable complex is formed; however the method depends on the stoichiometric composition of

the complex (Petra, 2004). Supposing there is a 1:1 formation of ion-pair between the cationic

dye and the anionic surfactant; then the equilibrium constant is:

CD + E� CD − E (5)

The Kf can be obtained from the plot of corrected absorbance, A> against the volume fraction

of the surfactant 0. The measured A> at 0 = 0B is compared to theoretical A>0 which is

derived by extrapolation of the linear parts of the curve to their intersection. The ratio of A> to

A>0 represents the degree of association, (1-β).

FG

FGH= (1 − I) (6)

Kf

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Where β is the degree of unassociated ions; since the dye and the surfactant are of equal

concentration, then �� = �! =� , then the equilibrium constant expression can now be written

as:

KL =[NO�P]

[NOR][PS]=

(T�U)

(VWXH)UW

=(T�U)

XHUW (7)

T

:; is the concentration of the dye and surfactant in a 1:1 ratio.

Conductometric Approach to Studying Dye-Surfactant Interaction: In order to study the ion-

pair formation between MBCl and SNa, the conductivity measurement would be done at the

premicellar concentrations of the surfactant and at low concentration of the dye. The specific

conductivities of the surfactant and the dye in the absence of the surfactant would be taken for

about thirty different concentrations. The specific conductivity of the dye-surfactant system as

a function of the surfactant concentration would be taken. To obtain the dye-surfactant system,

a solution of the dye would be used to prepare the concentrated stock solution of the

surfactant. All measurement would be taken at 250C.

Determination of Equilibrium Constant: If we assume a 1:1 ion-pair formation, then the

equilibrium reaction would be:

CD + E� CD − E (8)

In order to determine concentration of free and bound surfactant and dye ions as well as the

value of the equilibrium constant, the measured conductivity which is the sum of the

contribution of all free ions in the solution cannot be solely depended upon. A theoretical

K

15

model which describes the condition within the solution must be applied. This model has been

previously used by Bracko and Span (2001), Halide and Kartal (2005), Sibel and Duman (2006)

and more recently Nora (2012) to study various surfactant-dye interaction conductometrically.

The model assumes that the cationic dye MB+ and the anionic surfactant S

- form a non-

conducting ion-pair in the solution.

Based on Kohlrausch’s law, we know that:

ɅNOXZ; = �NOR

; + �XZS; (9a)

and ɅP[�; = �PS

; + �[�R;

(9b)

Where ɅNOXZ; and ɅP[�

; are the equivalence conductances of the dye and surfactant

respectively at infinite dilution; �NOR; , �PS

; , �[�R;

and �XZS; are the equivalent ionic conductances

at infinite dilution. Ʌ values can be determined experimentally from the specific conductivities

of the surfactant and the dye by converting them to equivalent conductance using:

Ʌ =T;S\]

X (10)

Where C is the molar concentration; the values of Ʌ; can be determined by plotting Ʌ

against√:. The intercept of the plot on the Ʌ-axis is the Ʌ;. Using the values of �[�R;

and �XZS;

from the literature, one can write:

�NOR; +�PS

; = ɅNOXZ; + ɅP[�

; − (�[�R; + �XZS

; ) (11)

Then the equilibrium constant can be expressed as:

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K =[NO�P]

[NOR]`[PS]` (12)

Where[CD − E], [CD]Land [E�]L are the concentrations of ion-pair, free dye and surfactant

ions respectively.

The concentrations of the free ions cannot be easily determined and so, they are expressed in

terms of [CD]7 and[E�]7, the total dye and surfactant concentrations respectively, so that

[E�]7 = [E�]L + [CD − E] and (13a)

[CD]7 = [CD]L +[CD − E] (13b)

The observed specific conductivity abc= can be expressed as sum of specific conductivity of

surfactant a= and the specific conductivity of the dye a9 if there were no surfactant-dye

interaction.

abc= = a= +a9 (14)

This means that before the ion-pair formation, the surfactant-dye interaction is negligible, and

then;

10��abc= = �PS[E�]7 + �[�R[d�]7 + �NOR[CD

]7 + �XZS[:'�]7 (15)

But with the formation of ion-pair, a decrease in the concentration of free ions occur and so

equation (14) can be written in terms of the concentration of the conducting species, free ions.

10��abc= = �PS[E�]L + �[�R[d�]7 + �NOR[CD

]L + �XZS[:'�]7 (16)

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Since the ion-pair is a non-conducting specie, then equations (13a) and (13b) can be rearranged

to give the concentration of the free ions in terms of the total concentration of the dye and the

ion-pair.

[E�]L = [E�]7 − [CD − E] and (17a)

[CD]L = [CD]7 −[CD − E] (17b)

Equations (17a) and (17b) can be inserted into equation (16) in order to obtain:

10��abc= = �PS([E�]7 − [CD − E]) + �[�R[d�

]7 + �NOR([CD]7 −[CD − E]) + �XZS[:'

�]7

(18)

Subtracting equation (18) from (15) cancels out the total concentration terms and yields the

‘specific conductivity’ of the ion pair:

10��3a = [CD − E](�NOR + �PS) (19)

So that 3a is the difference between the theoretical and measured specific conductivities at a

givien surfactant concentration. Kohlrausch’s law for infinite dilute solution of an electrolyte

can be applied to equation (19) to obtain:

10��3a ≈ [CD − E](�NOR; +�PS

; ) = [CD − E]Ʌ;NO�P (20)

Where Ʌ;NO�P is the equivalent conductance of the ion-pair at infinite dilution, Ʌ;NO�P value

would be determined experimentally by measuring the specific conductivities of the dye and

surfactants.

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The equilibrium constant can be calculated by inserting equations (17a) and (17b) into equation

(12):

K =[NO�P]

([PS]f�[NO�P])([NOR]f�[NO�P]) (21)

The Gibbs free energy for the ion-pair formation at 250C can be calculated as:

∆h; = −ij'�K (22)

THE FENTON’S REACTION

The degradation studies of Sodium lauroylsarcosinate will be done at relatively lower

concentration of the surfactant than the oxidant concentrations in order to be able to monitor

the reaction rate. The initial concentrations will be at proportions [H2O2]0=100[SNa]0=2[Fe2+

]0 at

a constant temperature of 250C and a pH of 3.

Procedure: An acidified water (pH=3) is used to prepare the surfactant at very low

concentration (below its CMC) and the Iron (II) tetraoxosulphate (VI) salt. Hydrogen peroxide is

freshly prepared in an amber bottle before the start of any experiment. The reaction takes

place in 500 ml vessels that are opaque to light. A calculated volume of Fe2+

solution prepared

is added to the solution of the surfactant and the mixture is then agitated with the aid of

magnetic stirrer. 25 ml of this mixture is taken before the H2O2 is added. This corresponds to

the concentration of the surfactant at time t=0. A known volume of H2O2 is then added to the

remainder. To monitor the reaction progress, 25 ml of the sample after the H2O2 has been

added is taken at various times (t= 1, 5, 15, 30, 45, 60, 90, 120 minutes). The H2O2 is only added

at the beginning of the reaction. Each sample is neutralized by a known amount of sodium

19

hydroxide to stop the reaction at the predetermined time. All samples are brought back to the

working temperature for analysis. The reaction can be repeated at varying concentrations of

the H2O2 and Fe2+

but at constant [SNa]0 in order study the effect of varying Fenton's reagent

concentration on the oxidation of the surfactant.

Analysis of the Samples: Alkaline solutions of chloroform and methylene blue would be added

to each sample. The biphasic solution formed is then shaken thoroughly to ensure the

distribution of the components throughout the organic and aqueous phases. The dye molecules

should form ion-pairs with the residual surfactant molecules in the solution. It has been shown

in an equilibrium studies of anionic surfactants (AS) with methylene blue, and their associated

ion-pair AS-MB in water and chloroform phases, that both AS and MBCl molecules alone are

never transferred to the chloroform phase but are rather associated forming an ion-pair AS-MB

(Koga et. al., 1999). On this basis, the absorbance of the solution (in the chloroform phase) is

then measured at a ����.

Determination of Surfactant concentration in the Samples: The absorbance of the chloroform

phase is related to the surfactant concentration. This relationship can be determined by

drawing a calibration profile. To obtain this, different standard solutions of surfactants are

prepared and each is added to a chloroform- MBCl system. The mixture is agitated; the ion-pair

extracted into the organic phase and the absorbance measurement is made. A plot of

absorbance against the varying concentration of the surfactant gives the relationship between

the measured absorbance and the concentration of the surfactant.

20

Determination of Rate Law: the data obtained would be used to determine the rate law of the

reaction.

21

REFERENCES

Anjali Pal, Asok Adak and Manas Bandyopadhyay (2005): Spectrophotometric Determination of

Anionic Surfactant in Wastewater Using Acridine Orange. Indian Journal of Chemical

Technology, Vol. 12, March 2005, pp. 145-148.

Anwar H., Brown M.R., Britten A.Z. and Lambert P.A. (1983): Disruptive effects of tris and

sodium lauroyl sarcosinate on the outer membrane of Pseudomonas cepacia shown

by fluorescent probes. J. Gen. Microbiol. 129(7), 2017-2020

Babak Samiey and Fatemeh Ashoori (2010): Kinetics of Crystal Violet Fading in the Presence of

TX-100, DTAB and SDS. Acta Chim. Slov. 2011, 58, 223-232.

Djedjess Essoh Jules-Cesar Meledje, Kouadio Pierre Kotchi, Loukou Kouakou and Boko A.K.A

(2010): Kinetic Study of Catalytic Oxidation of Sodium Dodecylsulphate by Fenton’s

reagent in Aqueous Solution. Australian Journal of Basic and Applied Sciences, 4(6):

1203-1214, 2010.

Guang-Guo Ying (2006): Fate, Behavior and Effects of Surfactants and their Degradation

Products in the Environment. Environment International 32 (2006) 417-431.

Halide Akbas and Cigdem Kartal (2007): Conductometric Studies of the Interaction of C.I.

Reactive Orange 16 with cationic Alkyltrimethylammonium bromide Surfactants. Dyes

and Pigments 72 (2007) 383-386

22

Hilal Nora M. (2012): Association Behavior of Anionic Azo Dye (AR88) With Surfactants As

Seen By Electrical Conductivity Measurements. International Journal of Research in

Chemistry and Environment, Vol.2 Issue 1 January 2012 (236-241).

Hwan Lee, Youn Lee, Hea-tae Kim, and Sang-ho Nam (2000): Chemodegradability of Linear

Alkylbenzene sulfonates by Chemical Oxidants. Environ. Eng. Res. Vol. 5, No. 1, pp. 41-

46. Korean Society of Environmental Engineers

Jing-Liang Li and Bing-Hung Chen (2009): Surfactant-mediated Biodegradation of Polycyclic

Aromatic Hydrocarbons. Materials, 2, 76-94 ISSN 1996-1944

Masaaki Koga, Yasushi Yamamichi, Yasuyo Nomoto, Maki Irie, Toshifumi Tanimura and

Tetsutaro Yoshinaga (1999): Rapid Determination of Anionic Surfactant by Improved

Spectrophotometic Method Using Methylene Blue. Analytical Sciences, June 1999, Vol.

15. The Japan Society for Analytical Chemistry

Mohd Ariffin Abu Hassan, Rozilawati Yusof and Siti Hajar Anaziah Muhamad (2008): Fentons

Degradation of Linear Alkylbenezene Sulphonates (LAS). Journal of Chemical and

Natural Resources Engineering, 2:22-30

Norfazrin Mohd Hanif, Siti Nurul Nadiah Adnan, Mohd Talib Latif, Zuriat Zakaria, Md. Pauzi

Abdullahand and Mohd Rozali Othman (2012): The Composition of Surfactants in River

Water and Its Influence to the Amount of Surfactants in Drinking Water. World Applied

Sciences Journal 17(8): 970-975, 2012

23

Owoyomi Olanrewaju, Jide Ige, Oladega Soriyan, Ogunlusi Grace, Olaseni Segun Esan and

Oladimeji Olanrewaju (2007): Kinetics and Mechanism of the Alkaline Fading of

Brilliant Green in Aqueous Solutions of a Double-tailed and Some Single-tailed

Cationic Surfactants. Acta Chim. Slov. 2007, 54, 370-374.

Petra Forte Tavcer (2004): Interaction between Some Anionic Dyes and Cationic Surfactants

with Different Alkyl Chain Length Studied by the Method of Continuous Variation.

Dyes and Pigment 63 (2004) 181-189

Petra Forte Tavcer and Joze Span (1999): Dye-Surfactant Interactions Studied Using Job’s

Method. Textile Res. J. 69(4), 278-284(1999)

Rosen, Milton. J. (2004): Surfactant and Interfacial Phenomena. A John Wiley & Sons, Inc.,

Publication,pp. 31-33.

S. Javadian , F. Hooshmand and A. Asadzadeh Shahir (2012): Aggregation of an Anionic Azo Dye

with Conventional Cationic Surfactants in Premicellar Region. Progress in Color,

Colorant and Coatings 4(2011), 121-128.

S.A.R. Mousavi, A.H. Mahvi, S. Nasseri, and Sh. Ghafari (2011): Effect of Fenton Process

(H2O2/Fe2+

) on Removal of Linear Alkylbenze Sulphonate Using Central Composite.

Iran. J. Environ. Health. Sci. Eng. 2011, Vol.8, No. 2, pp.129-138

Sabina Bracko and Joze Span (2000): Conductometric Investigation of Dye-Surfactant Ion Pair

Formation in Aqueous Solution. Dyes and pigments 45(2000) 97-102

24

Sabina Bracko and Joze Span (2001): Anionic Dye-cationic Surfactant Interactions in Water-

Ethanol Mixed Solvent. Dye and Pigments 50 (2001) 77-84

Sarah Hatfield Venhuis and Mehrab Mehrvar (2004): Health Effects, Environmental Impacts,

and Photochemical Degradation of Selected Surfactants in Water. International Journal

of Photoenergy, Vol.6 (2004) 115-125.

Sibel Tunc and Osman Duman (2006): Investigation of Interactions between Some Anionic

Dyes and Cationic Surfactants by Conductometric Method. Fluid Phase Equilibria 251

(2007) 1-7

Sinem Gokturk and Melda Tuncay (2003): Dye-Surfactant Interaction in the Premicellar Region.

Journal of Surfactants and Detergents, Vol.6, No. 4, pp. 325-330

Tharwat F. Tadros (2005): Applied Surfactants: principle and Application. WILEY-VCH Verlag

GmbH & Co. KGaA, WeinHeim, pp. 19-32

Venkataraman, N.I. and Subrahmanyam, V.V.R (1985): Effect of Structure on Substance of

Sodium salts of N-acylamino Acids in Aqueous Solutions. J. Indian Chem. Soc., 62, 507-

512.

W.B Smith (1963): The Analysis of Synthetic Detergent. A Lecture Delivered Before the Society

on 15th May, 1963. Journal of the Society of Cosmetic Chemists, pp.513-527