Investigation of the Fate ofInvestigation of the Fate of Dispersed Oil in Aquatic Systems

James BonnerJames BonnerMichael Sterling

Cheryl PageCheryl PageChris Fuller

Texas A&M UniversityC ll St ti TX USACollege Station, TX, USA

Early Oil Spill Research

• Emphasized fundamental “basic” science and hypothesis testingscience and hypothesis testing

• Advocated surface science principles “colloidal” applied to oil spill research

• His work led to other investigators winning Nobel Prize

• Advocated in situ oil spill monitoring• Advocated in situ oil spill monitoring to gain insight to behavior and understanding

• Advocated Intentional Release of Oil & Scaled experiments

• Could not get a U S permit soBen Franklin -- 1st U. S. Oil Spill ResearcherCould not get a U.S. permit, so

conducted research in Englandp

Presentation ObjectivesDiscussion points & results involving:

• experiments with crude oil dispersions at multiple scales including laboratory, mesocosm, controlled field and full field scale;

• ‘scaling’ as a primary experimental design criterion;

• theoretical hypothesis testing involving mathematical modeling approaches;

• Understanding of key environmental processes is critical to the understanding, prediction, and management of dispersed oil fateunderstanding, prediction, and management of dispersed oil fate in aqueous systems.

PhD Pipeline ProjectHistorical OverviewHistorical Overview

(1993-current)• Funded by Texas General Land Office (TGLO,

API, MSRC, NSF, ONR, COE, TCEQ, NYSRF. ExxonMobil, ARO, DOD, DOE, CODAR, FI…….. Others

• Long-term collaboration for better understanding of oil spill remediation technology

• Multi-disciplinary research team

Comprehensive and Fully Integrated Research Program

Full-Scale Fieldty

Research Program

Controlled Field

App

licab

ilit

Mesocosm

Laboratory

cale

and

Acr

easi

ng S

Inc

Increasing Experimental Control

“Solubility” Aqueous phaseLaboratory Studies

Bi fBiosurfactants

Rh d H 13ARhodococcus H-13A

Biodegradation kinetics

Toxicity Analysis

Dispersed Oil & N hth l T i itNaphthalene Toxicity

Environmental Science & Technology 31(2), 556-561, 1997

Environmental Toxicology and Chemistry, 23(12), 2941-2949, 2004.

Biosurfactant-Enhanced Aqueous Concentration of Methyl-Substituted Naphthalene

Environmental Science & Technology 31(2), 556-561, 1997

CDO Properties and Aggregation

CDO Dynamic Size Distribution

Clay-Oil Aggregate Formation over Time(initial clay-oil ratio 1:3 Gm = 20s-1)

3 00E+04

3.50E+04

4.00E+04

4.50E+04

5.00E+04

( m

3 /cm

3 )

(initial clay-oil ratio 1:3 Gm = 20s-1)

5.00E+03

1.00E+04

1.50E+04

2.00E+04

2.50E+04

3.00E+04

Volu

me

Frac

tion

(

0.00E+000 15 30

Time (min)

CDO Biodegradation RatesAt these ese

Rates in

3 Days

95%

Reduction

At these Rates in30 Daysy95%Reduction

Real-time In situ Sensor Development

Sensor Results

Observed30354045

ter

(m

)Modeled 0

510152025

Mea

n D

iam

et0 2

Time (hr)

CoulterFlowCAM ESDLISSTFlowCAM Fmax

Time (hr)

Robotic In Situ Sensors Results

37.3

37.4

37.5level 1level2level3level4level5

5000

6000

(ul/l

)

level 1level2level3level4level5

36 9

37

37.1

37.2

Sal

inity

(psu

)

level5

2000

3000

4000

Tota

l Par

ticle

Vol

ume

Conc

.(

0 5 10 15 20 2536.7

36.8

36.9

Time(hr)

0 5 10 15 20 250

1000

Time(hr)

T

Meso-scale (SERF)(SERF)

(Shoreline Environmental

Research F ili )Facility)

Wave Tank Scaling• Testbed = Corpus Christi Bay ---- Frtestbed• Model system = SERF wave tank -Fr model• Scaling factor

– Fr=[inertial force]/[gravity force]0.5 = V/(g* L)0.5

where g gravity, L is the wave length, V is the velocity or wavewhere g gravity, L is the wave length, V is the velocity or wave celerity

• Wave length for linear waves 2

2gTL

2 gTgTL• Wave velocity • Shear rate

i i i

22gT

TgT

TLV

5.0

PG• Power Dissipation

V

PGm

3

22 ),1(,,

skgmmCECEVGP crestwidthgareagaream

s

SERF: Dispersant Study (toxicity effects)

O tOyster deployment in

tanks

Crab cages on the beach

Oiled snails on the beach

Chamber for Sheepshead Minnow study

SERF: Dispersant Study (oil mass balance)(oil mass balance)

Water Research 34(9): 2507-2516, 2000

Oiled Control CDO

5

6

7

PH) 5

6

7

H)

Initial TPH mass = 5.15 kgInitial TPH mass = 5.65 kg

2

3

4

Mas

s (kg

of

TP

2

3

4

Mas

s (kg

of

TPH

0

1

12 24 96 240

M

0

1

2

12 24 96 240

M

Time (hr)

sediment water cumulative effluent Free-phase oil

-112 24 96 240

Time (hr)

SERF: Dispersant Effectiveness ExperimentsExperiments

iDispersant Application

( lib t d(calibrated delivery rate)

SERF: Dispersant Effectiveness E i tExperiments

Wave In-Situ sensorsDissipator

In Situ sensors

Controlled-Field StudiesSan Jacinto

Wetland ResearchResearch Facility,

(SJWRF)(SJW )

• Controlled application of oil: to evaluate the behavior and effects of chemically-dispersed oil (CDO) in a wetland setting • Monitored sediment petroleum pchemistry; toxicity; microbial numbers; nutrients………..

Controlled Application of Oil

Soil sample processingSoil sampling

120140160

g-ho

pane

)Dispersed Oil in

Wetlands

6080

100

Con

c (n

g/ng

(Total Target Saturates)

Wetlands

Control 02040

0 20 40 60 80 100ControlControlHigh-CDOHigh-CDOLow-CDO

0 20 40 60 80 100Time (days)

4045

ane)

Low-CDO

25303540

(ng/

ng-h

opa

101520

Con

c.

(Total Target Aromatics)

05

0 20 40 60 80 100Time (days)

Full-Field Studies: Texas Coastal Waters

AT 502

Fluorescein dyeFluorescein dye

Rhodamine dyeRhodamine dye

Both dyes apparent

Model Simulation Results with Passive Tracer (over

three tidal cycles)

t = 12 hrs t = 24 hrs t = 36 hrs

t = 48 hrs t = 60 hrs t = 84 hrs

Figure 1. Evolution of diffusing conservative material over three tidal cycles; run #1. The arrows representing the current vectors are colored for relative strength from blue to red on a scale of 0-150 cm/s.

Color scale: from blue to red (0 to 150 cm/s)

Conclusions

• Chemically-dispersed oil y p– Behaves like particle ‘colloid’ (10-100um)

Biodegrades– Biodegrades– Aggregates w/ ambient particles– Aggregates w/ oil particles– Accumulates Less on surfaces ‘beaches,

shorelines, & wetlands– Is transported like other environmental particlesIs transported like other environmental particles