AD-A25 2 359

SCR 92.004

June 1992

An Investigation Conducted byMick F. Arthur, G. Kelly O'Brien,

Sarah S. Marsh, and Thomas C. Zwick

Contract Report BATTELLEColumbus Division

EVALUATION OF INNOVATIVEAPPROACHES TO STIMULATE

DEGRADATION OF JET FUELS INDr 'o,• SUBSOILS AND GROUNDWATERELECTE !ý-I"JUL 07 li92

A Abstract The objective of this study was to evaluate the feasibility of surfactant-enhanced biodegradation of JP-5 in soil from Patuxtent Naval Air Test Center(NATC) under simulated conditions of soil venting. Surfactants and emulsifierswere screened for microbial toxicity and for their capacity to solubilize jet fuel fromsoil Three surfactants were subsequently evaluated in 60-day flask aerobic biode-gradation experiments. One surfactant was tested in soil columns under simulatedsoil venting conditions for 47 days. The results of the soil column study showedthat the surfactant plus soil venting failed to enhance biodegradation of JP-5 com-pared to soil venting alone. Soil venting appears to overcome oxygen limitations inunsaturated soil and should be considered for enhanced biodegradation and soilbioremediation at NATC.

92-17527

NAVAL CIVIL ENGINEERING LABORATORY PORT HUENEME CALIFORNIA 93043-5003

Approved for public release; distribution is unlimited.

92 7 0P ~

ii 0

11 -le. • 00e! - Nslj0 J 0-

9 ; ; 4

1L I" Pll° "'I" I1 Lo a ' 2' Ic z

I'-o I 's11 1'7 I's H 1'4 12 2 V th3

Al ;:I .

).i i-ii - i

a aN

REPORT DOCUMENTATION PAGE

-l I om ,ti, I9 , m - • ~ i • Is Wgdm e I * &ow pr m SWOOMn. 0bcU.e W Ikrm woo•ad wi R .,oM 1215 .M4et wao Nis e.Sof 1204. AMwvkK VA 22202-4=02 mi Io "~ Offie *I M4 mumw &Wd 8,KVG Pouiwa A .a. Pi. (070401681 WM*iNo'i. DC20603

1. AGIM'f Un ONLY 11.01bfit* 1, REPOoft I"'lrM . 100ow TM "a DATIN OOV1

June 1992 F'nal; June 1988 - August 1989

"• Aw"" EVALUATION OF INNOVATIVE IL II

APPROACHES TO STIMULATE DEGRADATON PR - 71-033OF JET FUELS IN SUBSOILS AND GROUNDWATER C - DAAL03-86-D-O001

a •mWU - DN668034

Mick F. Arthur, G. Kelly O'Briea, Sarah S. Marsh.and Thomas C. Zwick

BATTELLE r- I IColumnhu Division CR 91004505 King AvenueColombos. Ohio 43210-2693

IL 01080011111 aU-QA9M IAMI APOS A00081S itaUOUr~Oh~fN

Naval Facilities Engineering Command I Naval Civil EngineeringChesapeake Division LaboratoryWashington Navy Yard Code L71Washington, DC 20374-2121 Form Hueneme, CA 93043

f =11. I IMNT n100

talt 01• mfiOWUI~qV•dLamTYKI 3TrAlMUSl [tlb INfl~lllt1•cOU OO

Approved for public release; distribution is unlimited.

I1 mmAci (MaMm " W"

The objective of this study was to evaluate the feasibility of surfactant-enhanced biodegradation of JP-5 in soil iromPatuxtent Naval Air Test Center (NATC) uAae simulated conditions of soil venting. Surfactants and emulsifiers weresceened for microbial toxicity and for their capacity to solubilize jet fuel from soil. Three surfactants were subse.quently evaluated in 60-day flask aerobic biodegradation experiments One surfactant was tested in soil columns undersimulated soil venting conditions for 47 days. The results of the soil column study showed that the surfactant plus soilventing failed to enhance biodegradation of JP-5 compared to soil venting alone. Soil venting appean to overcomeoxygen limitations in unsaturated soil and should be considered for enhanced biodegradation and soil bioremediation atNATC.

Surfactants, enuisifiers, bioremediation. soil, water, fuels, soil venting 2414L 10"M coot

1?. 1111UITIMCLAIICATMiO I&. SECA'J11 CLAS.AIiCAIO "•tWN•M SNTY CASOAMC•TO 2M LMTATM OF A&STIPAcTOP 1PONYT O TM PA" OF ARIOTPAC

Unclassifle.i Unclassified Unclassified UL

N 754041-290-6Mlo Stmed Fami 21 (PA,. 24911 "0 ANSI SK 23e-1

2W1•,02

pI

This report is a work prepared for the United States byBattelle. In no event shall either the United States orBattelle have any responsibility or liability for anyconsequences of any use, misuse, inability to use, orreliance upon the information contained herein, nor doeseither warrant or otherwise represent in any way theaccuracy, adequacy, efficacy, or applicability of thecontents hereof.

Acceio,,Fo F7•i-

rrTIS CRAV&IlH 1C AE?

U. a 1:1o0111,'.ed "

J -"i.ii;C:tiO,.1 ...............

By ...............................

AvailaCiiity COde-l

" " = ' • vai i jii I ior

Dit Sptecial

TABLE OF CONTENTS

INTRODUCTION . 1

SCOPE AND OBJECTIVES ................ ... 2

MATERIALS AND METHODS. ... ............... .............. .SOIL ..... 3SURFACTANT SELECTION .................. 4PRELIMINARY FLASK STUDIES .......... .... ............... 5SOIL COLUMN DESIGN AND TREATMENT SYSTEM . . . .... .... 7

RESULTS AND DISCUSSION. .................. .................. 8SURFACTANT SELECTION ................. .................. 8PRELIMINARY FLASK STUDIES ..................... 12SOIL COLUMN STUDIES .............. 17

CONCLUSIONS ........................ ......................... 21

LITERATURE CITED ................. ..................... 24

INTRODUCTION ............... ...................... ..... 1

SCOPE AND OBJECTIVES ................... .................... 2

MATERIALS AND METHODS .............. ..................... 3SOIL ......•...•... . ............... ........... ... .3SURFACTANT SELECTION................................... ..... 4PRELIMINARY FLASK STUDIES.............................. .SOIL COLUMN DESIGN AND TREATMENT SYSTEM........ ........ 7

RESULTS AND DISCUSSION ................. ................ 8SURFACTANT SELECTION ............. ................. 8PRELIMINARY FLASK STUDIES .......... ............... 12SOIL COLUMN STUDIES .............. .................. 17

CONCLUSIONS .................. ......................... 21

LITERATURE CITED ................. ..................... 24

ii

2

LIST OF TABLES

TABLE 1. SURFACTANTS AND EMULSIFIERS EVALUATED FOR THEIRUTILITY IN SOIL BIODEGRADATION EXPERIMENTS . ... 10

LIST OF FIGURES

FIGURE, CUMULATVE CO EVOLUTION THROUGH 60 DAYS FROMNATC SOIL 24 IMENDED WITH SURFACTANTS 21, 39,

AND 49- SQUARE, 21 LOW; PLUS, 21 HIGH; DIAMOND,39 LOW; TRIANGLE, 39 HIGH; X, 49 LOW; ANDINVERTED TRIANGLE, 49 HIGH .... ........... .. 13

FIGURE 2. JP-5 EXTRACTED FROM NATC SURFACTANT-AMENDEV SOIL24 USING WATER FOLLOWED BY ACETONE. A. DAY 0;B. DAY 32; C. DAY 60 ...... .............. 15

FIGURE 4. CUMULATIVE CO EVOLUTION THROUGH 47 DAYS FROMSOIL COLUMNS kdMENDED WITH SURFACTANT 21: SQUARE,21 HIGH; PLUS, 21 HIGH STERILE; DIAMOND, 21 LOW;TRIANGLE, 21 LOW STERILE; Z, NO SURFACTANT . . . 19

FIGURE 5. RECOVERY OF JP-5 FROM SOIL COLUMNS AFTER 47 DAYSOF AEROBIC INCUBATION WITH OR WITHOUT SURFACTANT21 ................... ................... 20

FIGURE 6. NICRCBIAL ENUMERATION ON NUTRIENT AGAR ANDMINERAL SALTS AGAR OF SOIL FROM SOIL COLUMNSAFTER 47 DAYS OF AEROBIC INCUBATION ......... .. 22

liii

FINAL REPORT

on

EVALUATION OF INNOVATIVE APPROACHESTO STIMULATE DEGRADATION OF JET FUELS

IN SUBSOILS AND GROUNDWATER

to

NAVAL CIVIL ENGINEERING LABORATORYCode L71

Port Hueneme, California 93043-2693

from

BATTELLEColumbus Division

August 25, 1989

INTRODUCTION

The Naval Civil Engineering Laboratory (NCEL) iscoordinating the decontamination of soils at the fuel farm ofPatuxent Naval Air Test Center (NATC), Patuxent River, Maryland.The soils at the fuel farm were contaminated with jet fuel (JP-5)in the winter of 1976-1977 when a pipeline connecting undergroundstorage tanks ruptured. Since that time, the fuel has movedthrough the sandy soils at the site. Currently, several acres ofsoil to a depth of approximately 20 to 30 feet, as well assurface waters, are contaminated with jet fuel. Concern isincreasing over the extent of fuel contamination and theprotection of groundwater in the area. Other hydrocarbons, such

as JP-4, also exist at the site.

NCEL is investigating options to cost-effectivelydecontaminate the vadose (unsaturated) zone in situ. Bydecontaminating the site, NCEL hopes to prevent futurecontamination of surface and groundwater. A potentially cost-effective method for in situ soil decontamination is themicrobially-mediated biodegradation of fuel hydrocarbons, thatis, bioremediation. This process is an attempt to stimulate the

2

microorganisms that are indigenous to the soil to metabolize fuel

hydrocarbons in situ. While most soils contain microorganisms:that are capable of degrading hydrocarbons in situ, the factorsthat limit the bioremediation process need to be overcome. Thesefactors may include restricted bioavailability of the

contaminant, nutrient limitations, potential toxicity of fuelhydrocarbons and associated contaminants, inadequate

reduction/oxidation (redox) potential, inadequate or excessive

moisture,' acidic or basic conditions, and oxygen deficiency.

SCOPE AND OBJETWVES

The objective of this research was to evaluateinnovative approaches for stimulating the degradation of jetfuels. in soils and potentially groundwater. The innovativeapproaches evaluated included the use of selected surfactants andemulsifiers to enhance the bioavailability of and thus thebiodegradation of jet fuels in contaminated soil collected fromthe vadose zone of the NATC fuel farm. Aerobic biodegradationexperiments with surfactant -amended soils were conducted in thelaboratory using both flask and soil column systems. Sterilecontrols were included to attempt to differentiate betweenbiological and physical-chemical degradation of jet fuel in thesoils.

A secondary experiment was conducted to determine theefficiency of air-stripping for the removal of volatile fuelcontaminants from groundwater samples collected from NATC. Theresults of the air-stripping experiment were reported previously;the previous report is included in the current report as AppendixA.

The results of this project should be applicable tofuture NC=L plans to implement in situ remediation at NATC,either through the use of biodegradation, physical (air-

3

stripping) removal of volatiles, or a combination of biological

and physical techniques.

MATERIALS AND METHODS

SOIL

The soil used in these experiments was collected from

NATC fuel farm wells 24 and 25 by personnel from IT Corporation.

Cuttings from the drilling of wells 24 and 25 were placed in

plastic-lined drums that were transported to Battelle's West

Jefferson Laboratory and stored at 40C. Field-moist soil sampleswere analyzed for microbial enumeration by dilution plating on

nutrient agar.Representative samples of soil 24 and 25 also were

analyzed for fuel hydrocarbon content as follows. Thirty grams

of soil were placed in a 250 ml flask and extracted with 100 ml

of acetone by orbital shaking for 30 minutes. The supernatant

was removed from the soil and 30 ml of the supernatant were

diluted to 100 ml with distilled water. The final volume (100

ml) was passed through a preconditioned C1 8 prep-sep column under

vacuum. The prep-sep columns were preconditioned with 1 to 2 ml

of methanol and distilled water. After the acetone-water soil

extracts were passed through the prep-sep columns, the columns

were eluted with 2 ml of methylene chloride. One microliter of

the methylene chloride eluates was then analyzed on a Varian 3700

gas chromatograph (GC) equipped with a flame-ionization detector

(FID) using JP-4 as standards. The GC conditions were as

follows:

Column: 6 ft. x 2 mm I.D. 3% OV 101

Gas flow rate: 20 ml/minute N2

Injector temperature: 600C

Detector temperature: 300"C

4

Column temperature: 40*C for 4 minutes, increasing

at 10OC/minute up to a final

temperature of 2500C, and held

at the final temperature for 4

minutes.Peaks were integrated with a Varian 4270 integrator and compared

to standards of jet fuel.

SMRPACTANT SELECTION

The objective of this task was to identify surfactants

and emulsifiers that effectively solubilized jet fuel when added

to soil at microbially non-toxic concentrations. Fifty-three

different surfactants and emulsifiers were tested for their use

in enhancing biodegradation of jet fuel in soil. The surfactantsand emulsifiers initially were identified based on

recommendations from major manufacturers and through thesurfactant/emulsifier literature. The surfactants andemulsifiers then were screened for their toxicity tomicroorganisms (using a Microtox bioassay system). Non-

inhibitory materials then were screened fon their ability toemulsify and release jet fuel from soil at microbially non-toxic

concentrations as follows.

To screen each surfactant or emulsifier, its ability toextract jet fuel from soil was compared to both water and

acetone. For water extractions, 10 g of soil 24 (which proved to

be the most contaminated soil based on the GC analysis describedabove) were combined with 20 ml of distilled water in a 40-ml

test tube. The soil and water were vortexed for 5 minutes andthe supernatant was separated from the soil by filtration through

#1 Whatman filter paper. The supernatant was diluted to 100 mlwith distilled water and then passed through a Cis prep-sep

column (conditioned with methanol and water). The column was

then eluted with 2 ml of methylene chloride for FID-GC analysis.

A l I I- | m

Acetone extractions were done similarly to the water

extractions. Twenty millilitezs of acetone were added to 10 g of

soil 24 and vortexed for 5 minutes. The slurry was then

filtered, the filtrate was diluted as before to 100 ml withdistilled water, passed over a preconditioned C1 8 prep-sep

column, and eluted with 2 ml of methylene chloride for FID-GC

analysis.

Finally, the surfactant and emulsifier extractions ofsoil 24 were done similarly. Twenty milliliters of theappropriate concentration of each surfactant or emulsifier werevortexed for 5 minutes with 10 g of soil 24, filtered orcentrifuged, diluted to volume with distilled water, passedthrough a prep-sep column, extracted with methylene chloride, andanalyzed for hydrocarbons by FID-GC.

Thus, the capacity of non-toxic concentrations of each3urfactant or emulsifier to extract jet fuel from soil 24 wascompared to extractions with both water (presumably little or noextracting capacity) and acetone (presumably nearly 100 peruentextracting capacity). The assumption was that the ability tosolubilize jet fuel from soil is related to enhancing thebioavailability of the jet fuel to soil microorganisms. As a

result of this screening, three surfactants were selected forpreliminary flask studies of jet fuel biodegradation in soil 24,as described below.

PRELZMIIARY FLASK STUDIES

A flask study was setup to preliminarily evaluate theutility of three surfactants--numbers 21, 39, and 49--to enhancejet fuel biodegradation in contaminated soil 24. Surfactants 21,39, and 49 were GAY Emulphor ON-870, Thompson/Hayward T-Det N-95,

and Texaco Surforic N-95, respectively. The factorialexperimental design included two concentrations of each of thethree surfactants (in triplicate replication) in 250-mI biometer

6

flasks containing 100 g (on a dry-weight basis) of T A ' 24.Each biomete= flask was equipped with a side-arm tu.e c aining10 ml of 0.6 N NaOH to trap evolved C02. The surfa-t. tconcentrations included 0.5 and 1.0 percent (v/w,surfactant/soil). The soil in all flasks was amended withRestore 375 at the recommended rate of 2 g/100 g soil. Themoisture content of the soils was maintained at 60 percent offield capacity and the flasks were incubated aerobically in thedark at 230C. A sterile control (one replicate) was included foreach surfactant. The sterile controls were obtained by theaddition of 500 pg/g Cd (as CdCl 2 ) and 500 pg/g Hg (as HgCl 2 ) tobiometer flasks containing nutrient-amended soil 24 andsurfactant. Moisture was maintained at approximately 60 percentof field capacity in all flasks by the weekly addition of water(sterilized water for the sterile controls), if necessary.

Bicdegradation was monitored by measuring the cumulativeevolution of CO2 from each flask over a 60-day incubation period.Also, at days 0, 30, and 60, appropriate flasks were sacrificedand the soils were analyzed for fuel hydrocarbon concentrationsand microbial enumeration. Cumulative CO2 was measured by weeklysampling and recharging NaOH traps. The NaOH removed from thebiometer flask at each sampling was combined with 5 ml of 1.3 NBaC 2 to precipitate absorbed CO2 as BaCO3 . Evolved CO2 wasdetermined by titration of unreacted NaOH against standardizedHCI, using a Fisher Automatic Titrator-ZI.

The jet fuel concentration in flask at days 0, 30, and60 was determined by a dual extraction of 10-g aliquots of eachsoil, using water followed by acetone. The extraction and FID-GCprocedures were as described previously, except that a Hewlett-Packard 5890 gas chromatograph with FID was used. Microbialenumeration by the soil dilution plating technique was carriedout on both mineral salts agar containing a JP-4-saturated filterpaper taped to the petri dish lid, and nutrient agar.

7

The results of the preliminary flask study led to the

identification of surfactant number 21 as a likely candidate forscale-up to soil column studies. Thus, soil columns containing

fuel-dosed soil 24 dosed with surfactant 21 were setup, asdescribed below.

SOIL COLUMi DESIGN AND TREATMENT SYSTEM

"Soil 24 was amended with Restore 375 (2 g/100 gsoil) and JP-5 to obtain a final fuel concentration of 150 Aglg.Fifteen, 12 inch x 1.5 inch glass columns containing 250 g (dryweight basis) of fuel-dosed soil 24, and three empty (methodblank) columns, were placed vertically in a specially designedwooden rack. The ends of each column were sealed with one-holerubber stoppers. The bottom stopper (air inlet) contained afritted glass tube to aid in gas dispersion; the fritted tube waspacked 2 to 3 inches deep with glass wool to prevent breakage orplugging. The bottom stopper of each tube was connected to amanifold that delivered CO2 -free air. That is, incoming room airpassed through an activated carbon filter, then through abackflush trap, then through a solution of 1 N NaOH (tc removebackground C02 ), and finally into a stainless steel manifold withan independent connection to each soil column. The top stopper(air outlet) of each column was connected via tubing to a C02 -trap (1 N NaOH, to capture microbially evolved CO2 from the soilcolumns), which in turn was connected to two in-line Orbo tubes(Supelco) for trapping organic volatiles, and finally to a multi-channel peristaltic pump. Thus, each column was independentlyaerated at a controlled rate, and evolved C02 and organicvolatiles were trapped from each column.

The experimental design included two concentrations ofsurfactant 21--0.5 and 0.2 percent (w/w, surfactant/soil)--intriplicate. Control columns included three 0-dose soils (thatis, no surfactant), and triplicate sterile controls for each

8\

surfactant concentration. The sterile controls were obtained bydosing the soils with 500 #g/g Cd (as CdCI 2 ) and 500 pg/g Hg (asHgCI 2 ). Moisture was gravimetrically maintained at approximately50 percent of field capacity in by the addition of water

(sterilized water for the sterile controls), if necessary.

The cumulative evolution of CO2 from each column wasdete-mined over a 47-day incubation period. Cumulative C02 wasmeasured by weekly sampling and recharging NaOH traps, as

described previously. At day 0, the soils were analyzed for fuel

hydroca..bon determination and microbial enumeration as described

earlier. At day 47, the columns were sacrificed and the soilswere again analyzed for fuel hydrocarbon concentrations andmicrobial enumeration.

RESULTS AND DISCUSSION

SURFACLANT SELECTION

One of the factors that appears to limit thebiodegradation process in soils is that the target compound maybe inaccessible (not bioavailable) due to adsorption or is coatedwith impenetrable materials (Hill, 1978; Knezovich et al., 1987).

Surfactants and emulsifiers have been used with mixed success toat'impt to enhance the bioavailability of recalcitrant compounds(Urano and Saito, 1985). Thus, the objective of the surfactantscreening task was to identify surfactants and emulsifiers thatwould enhance the bioavailability of fuel hydrocarbons in soil,yet would not inhibit soil microbial activity. Theidentification of a cost-effective method for improving thebioavailability of fuel hydrocarbons in soil could then be scaledup and evaluated in flask, column, and eventually field studiesfor in situ bioremediation.

The surfactant screening revealed that most of thesurfactants and emulsifiers examined were either microbially

9

toxic or ineffective at solubilizing fuel hydrocarbons from soil.

A number of surfactants and emulsifiers were evaluated for their

microbial toxicity (Table 1). Those exhibiting relatively low

toxicity in the Microtox Bioassay system were screened further

for their ability to solubilize JP-5 from soil, relative to

acetone.

Based on the initial screening, three surfactants or

emulsifiers were chosen for flask..studies. These included

surfactants/emulsifiers numbers 21, 39, and 49. These three

surfactants were chosen because of their combined low or non-

toxic nature as determined by the Microtox bioassay, and their

ability to solubilize fuel hydrocarbons from soil. The gamma

values in Table 1 are relative values of toxicity to

Photobacterium 2hosghoreum of the Microtox bioassay; the higher

the value, the more toxic the test material. The gamma value for

surfactant 21, 39, and 49 when tested at concentrations of 0.45

percent (v/v) were 0.04, 0, and 0, respectively. On the other

hand, some materials, such as surfactants 22 and 53 at the same

test concentrations, were highly toxic and gave gamma values of

14.2 and 31.1, respectively.Materials 21, 39, and 49 also proved to be relatively

effective at solubilizing JP-5 in soil. Surfactant 49, an

alkylphenol et1hgxy-laze, at a 1 percent (v/w) concentration was

the most effective surfactant tested for extracting jet fuel from

soil; its value relative to acetone (i.e., 100 percent) was 137

percent. Surtactant 49 at a 0.5 percent (v/w) concentration also

was relatively effective at solubilizing jet fuel from soil; its

value relative to acetone was 108 percent. Surfactan: 39 was a

Snonylpheno. ethoxLate and at 0.5 and 1 percent (v/w) yielded

values of 108 and 93 percent, respectively, relative to acetone.Finally, surfactant 21, a polyoxyethl4ated oleyl alcohol, at 0.5

and 1 percent (v/w) concentrations was 97 and 81 percent,

respectively, as effective as acetone.

10

TABLE 1. SURFACTANTS AND EMULSIFIERS EVALUATEDFOR THEIR UTILITY IN SOIL BIODEGRADATIONEXPERIMENTS.

SolubilityCapacityRelative toAcetone(Percent)

ConcentrationNumber Surfactant GammaM1 ) 0.5% 1.0%

1 Shell Neodol 23-6.5T 1.63 nd ( 2 ) nd2 Shell Neodol 23-6.5 7.91 nd nd3 Shell Neodol 25-9 3 nd rd4 Shell Neodol 91-2.5 -Ji) nd nd5 Shell Neodol 91-6 nd nd6 Shell Neodol 91-8 -- nd nd7 Milliken SynFac 222 0.18 59.3 97.38 Milliken SynFac 334 0.16 33.6 89.59 Milliken SynFac 334-13 0 9.9 9.910 Milliken SynFac 8210 0.48 29.9 131.011 Milliken SynFac 8216 0 63.9 71.312 Henkel Nopalcol 2-OL 16.12 nd nd13 Henkel Nopalcol 4-L 1.23 nd nd14 Henkel Nopalcol 6-L -- nd nd15 ICI Ahcowet RS -- nd nd16 XCI Tween 20 8.73 nd nd17 ICI Tween 80 1.12 nd nd18 AET Land Reclaimer -- 27.4 46.619 NL Aktaflo-E 2.87 nd nd20 Norman Fox Norfox -- nd nd

,Q--, GAF Emulphor 0N-870 0.04 114.0 97.522 GAF Emulphogene BC 420 14.22 nd nd23 GAP Igepal CO-520 0.08 15.9 85.024 GAP Peganat. L-20 3.22 nd nd25 Witco Witcomul 4143 -- nd nd26 Witco Witcomul 4144 -- nd nd27 Witco Witconate P-1059 8.73 nd nd28 Witco Witconate AOS 4.82 nd nd29 Mazer Chem Mazon 1086 1.54 nd nd30 Mazer Chem S-Haz 20 -- nd nd31 Mazer Chem S-Maz 80 -- nd nd32 Mazer Chem S-Maz 85 2.87 nd nd33 Mazer Chem T-Maz 20 2.14 nd nd34 Mazer Chem T-Maz 10 1.18 nd nd35 Mazer Chem T-Maz 85 1.37 nd nd36 Mazer Chem Mazawet 77 -- nd nd37 Thompson-Hayward T-Det N6 0 48.8 93.9

11

TABLE 1 (CONTINUED)

3.4 Thompson-Hayward T-Det N8 0 18.4 52.9a19) Thompson-Hayward T-Det N9.5 0 127.6 109.640 Henkel Agrimul JI 0.82 nd nd41 Henkel Agrimul 26-B 0.71 26.7 29.342 Henkel Agrimul Nopalco 4-0 2.19 nd nd43 Henkel Agrimul Nopalco 6-0 3.60 nd nd44 Lipo Chem Lipocol L-4 -- nd nd45 Lipo Chem Lipocol L-12 4.89 nd nd46 Lipo Chem Lipocol L-23 0.56 31.6 26.947 Lipo Chem Lipocol TD-12 1.57 nd nd,j• Texaco Surfonic N-40 -- nd ndI Texaco Surfonic N-95 0 122.5 153.4

Rohm and Haas Triton N-60 0.09 39.5 77.751 Rohm and Haas Triton N-57 0.25 42.0 70.152 Rohm and Haas Triton N-35 -- nd nd53 Rohm and Haas Triton N-45 31.13 nd nd

(1) Gamma is a rvilative toxicity value indicating the inhibitionof light outp;z by the test bacterium, PhotobacteriumPhosphoretim; the higher the value, the greater the toxicity.

(2) nd - not determined because of the relatively high toxicityof the material.

(3) -- - not determined because of solubility problems.

12

Therefore, materials 21, 39, and 49 were tested in flaskstudies to further ecreen for their microbial toxicity and theirability to solubilize fuel hydrocarbons in soil.

PNEL fKIXARY FLASK STUDIES

The objective of the flask studies was to test thematerials identified in the surfactant screening task for theirutility in biodegradation experiments with fuel-contaminated soilfzom NATC. Three endpoints were evaluated to assess theusefulness of surfactants 21, 39, and 49: cumulative evolution ofC02 from surf actant-amended contaminated soil through 60 days ofincubation; changes in JP-5 concentrations in the surfactant-amended soils through the incubation period; and changes innumbers of total heterotrophic and hydrocarbon-degrading bacteriain the surfactant-amended soils. Based on the results of theflask studies, one surfactant would be used in subsequent soilcolumn experiments.

Two concentrations for each of the three surfactantswere tested in the CO2 evolution experiments. High and lowconcentrations were 1.0 and 0.5 percent (v/w), respectively. Thehigh concentration of surfactant 21 resulted in the greatestevolution of C02 -C, 47 mg, among all treatments over the 60-dayaerobic incubation (Figure 1). This was followed in order by

surfactant 49 high (20 mg C02 -C evolved); surfactant 49 low (18mg C02 -C evolved); surfactant 39 high (15 mg C02 -C evolved); andsurfactants 39 high and 21 low (15 mg C02 -C evolution). Sterileand 0-dose controls were included for all treatments and evolvedapproximately 10 mg of'C02 -C over the 60-day aerobic incubation.

These results indicate either that surfactant 21enhanced the bioavailability_and biodeqLradation of fuelhydrocarbons in soil, or that it was itself biodegaded.to CO2 -C.Thus, at days 0, 30, and 60 during the 60-day aerobic incubation,soil samples from the flask experiment were extracted with both

13

//

!0/

40 n.2

Sn=oo

ýmm2

10 n,2

0 -q0 20 40 so

OAYS

FIGURE 1. CUMULATIVE CO EVOLUTICAN THROUGH 60 DAYS FROM NATCSOIL 24 AMENDED WITH SURFACTANTS 21, 39, AND 49:SQUARE, 21 LOW; PLUS, 21 HIGH; DIAMOND, 39 LOW;TRIANGLE, 39 HIGH; X, 49 LOW; AND INVERTED TRIANGLE,49 HIGH.

14

water and acetone and the extracts analyzed for JP-5. The

results (Figure 2) include the amount of JP-5 extracted from each

soil using both water and acetone, as described in the Materials

and Methods section. The results indicate a loss of hydrocarbons

through time in the high surfactant treatments compared to the

low surfactant treatments and no-surfactant controls. However,

decreases in JP-5 concentrations occurred in sterile soils with'high surfactant concentrations as well as microbially active

soils (Figure 2.c). The sterility of these soils was confirmed

by plating soil samples for microbial enumeration. Thus, the

loss in JP-5 from microbially active and sterile soils receiving

high concentrations of surfactants may have been due tovolatilization or some other physical or chemical process,

instead of biodegradation.

The soils from the CO2 evolution flask experiment were

enumerated on both nutrient agar and mineral salts agar in which

jet fuel was the only carbon source. The results for the

nutrient agar plating (Figure 3.a) show a general increase in

microorganisms from day 0 through the 30- and 60-day samplings.

The greatest increase in microbial numbers occurred with the high

concentration of surfactant 21; at days 30 and 60, 9.51x10 7 and

7.28x10 7 colony forming units per gram of soil (CYU/g),respectively, were enumerated on nutrient agar. All other

enumeration results for days 30 and 60 were an order of magnitude

less than for the high dose of surfactant 21. Similar resultswere obtained soil plating on mineral salt agar plus jet fuel

(Figure 3.b).

These enumeration results correlate with the evolution

of CO2 in the flask studies (see Figure 1). Thus, the increased

CO2 evolution from soil treated with surfactant 21 appears to be

the result of increased numbers and metabolic activity of

microorganisms. However, since the loss of JP-5 was comparable

in all soils treated with high surfactant concentrations (see

Figure 2), then the enhanced microbial activity in soil

/

cm II]N~N.15

'a,

II

7 7 -

G- d FAd 21. N T. U

X,

71

a .. 0 "awda - - - *.3 .43.4 t4

.USING WATER FOLLOWED BY ACETONE. A. DAY 0; S. DAY32; C. DAY 60.

16

28/

22.

a ,

RIHT THASRPEETSRFCAT 1HG,2

d ::

LOW 39 HIH 9LW 9LW N 9HG.B

RERSN 1HG ," 21LW §HG, 39 OW 4 HGH

tA

S ,

0ERSN !HG,2 LOW 39UG,3 O,4 IHAND 4904OW

I 2Z S i

17

containing the high concentration of surfactant 21 may not haveled to increased JP-5 biodegradation. This was unexpected sinceincreased microbial activity theoretically should result in fuelhydrocarbon degradation by cometabolism if not by directmetabolism. Therefore, to attempt to evaluate further thepotential use of surfactant 21 in enhanced biodegradation, it wasapplied to NATC fuel-contaminated soil in aerobically incubatedsoil columns.

SOIL COLUMN STUDIES

The soil column experiment was designed to simulate whatshould occur in the field under a soil venting situation. Thatis, in situ fuel biodegradation in subsurface soils tends to belimited by the supply of oxygen (API, 1987) and one mechanism tosupply oxygen is through soil venting. Thus, the soil columnexperiment combined aeration through soil venting with theaddition of a surfactant to enhance the solubility of fuelhydrocarbons in soil. Under these conditions, any loss of fuelhydrocarbons could be due to enhanced volatilization and/orenhanced biodegradation.

Cumulative evolution of C02 -C was determined over 47days of aerobic incubation of the soil columns containingnutrient-amended, JP-5-contaminated soil plus high (1.0 percent,v/w) and low (0.5 percent, v/w) concentrations of surfactant 21.Sterile controls were included that initially were sterilizedwith Cd and Hg as described in the Materials and Methods section.However, the sterile controls became contaminated during theincubation and thus were autoclaved. As a result, the sterilecontrols were useful for the CO2 evolution experiment but not forthe determination of residual fuel hydrocarbons by extraction ofthe soils because of the potential loss of JP-5 by volatilizationduring the autoclaving process.

19

Unexpectedly, soil columns containing both high and lowconcentrations of surfactant 21 evolved nearly the same amount of

C02 -C as the no-surfactant control soil columns (Figure 4). That

is, after 47 days of aerobic incubation, the amount of C02 -Cevolved from the no-surfactant control, surfactant 21-high, and

surfactant 21-low soil columns wa. 19.9 t 1.26, 21.4 * 6.16, and

20.4 * 5.18 mg C02 -C, respectively. In comparison, the

surfactant 21-high and 21-low sterile control columns evolved

7.99 * 2.86 and 10.7 * 5.97 mg C02 -C, respectively. Thus, unlike

in the flask experiment discussed in tho previous section, the

addition of surfactant 21 to nutrient-amended, fuel-contaminated

soil did not appear to stimulate microbial activity compared to

the no-surfactant control soil.To evaluate further the actions of surfactant 21 in the

soil columns, soil samples from each column were extracted at theconclusion of the 47-day aerobic incubation, as described in theMaterials and Methods section. The mean recovery of JP-5 from

the triplicate soil columns containing the high and lowconcentrations of surfactant 21 was 138 * 9.7 and 113 t 27 #g/g,respectively (Figure 5). In comparison, the no-surfactantcontrol soil columns contained 21 t 4.9 gg/g of JP-5 after the 47days of soil venting.

The interpretation of these results is not clear because

of the similar amounts of C02 -C evolved from the surfactant and

no-surfactant soil columns, as discussed above. That is, if the

loss of JP-5 from the no-surfactant control soil columns hadcorrelated with increased CO2 evolution relative to thesurfactant-treated soils, then a conclusion might be thatsurfactant 21 actually inhibited the biodegradation of JP-5.

Another possible interpretation of the results is that surfactant21 did indeed inhibit the biodegradation of JP-5 in the soil byserving as a preferred (or more bioavailable) carbon source. iftrue, then the evolution of CO2 from surfactant-treated soil

columns could be the result of the biodegradation of the

1 W1.1.17.74 'In .NWIII

19

20

18

15-

€) 14 -

4.

01 6:

OAY

FIGURE 4. CUMULATIVE CO EVOLUTION THROUGH 47 DAYS FROM SOILCOLUMNS AMENDED WITH SURFACTANT 21: SQUARE, 21 HIGH;PLUS, 21 HIGH STERILE; DIAMOND, 21 LOW; TRIANGLE, 21LOW STERILE; X, NO SURFACTANT.

20

140

130

120 -'

110

100

N 90

80

70

50

40

30

20

10

0- ____

21 HIGH 21 LOW 0 OOSED DAY 0

SOIL TREATMENTS

FIGURE 5. RECOVERY OF JP-5 FROM SOIL COLUMN~S AFTER 47 DAYS OFAEROBIC INCUBATION WITH OR WITHOUT SURFACTAN" 21.

21

surfactant itself, while C02 from the no-surfactant controlcolumns resulted from JP-5 biodegradation.

The interpretation of the 102 evolution and soil JP-5data is complicated further by the results of microbialenumeration in the soil columns. As in the flask study,surfactant 21 appeared to stimulate numbers of microorganisms onboth nutrient agar and mineral salts agar (Figure 6). Forexample, the numbers of nutrient ;.jar platable bacteria in thepresence of high and low concentrations of surfactant 21 were11.8x10 6 * 3.33x10 6 and 10.1x106 t 2.09x10 6 CTU/g, respectively.The no-surfactant control, on the other hand, yielded 2.79x10 6 _

3.18x10 6 CFU/g. 0imilarly, the numbers of organisms recoveredfrom soil dosed with high and low concentrations of surfactant 21and plated on mineral salts agar plus JP-5 were 3.69xl06_1.08x106 and 2.48x10 6 * 0.81x106 CFU/g, respectively. In thecase of mineral salts agar, the no-surfactant control yielded0.86x106 t 0.69x10 6 CFU/g. However, the increased numbers oforganisms in the presence of surfactant 21 did not lead toincreased evolution of CO2 (see Figure 4) or to increased loss ofJP-5 (see Figure 5).

CONCLUSIONS

The objective of this study was to evaluate thefeasibility of surfactant-enhanced biodegradation of JP-5 in soilunder simulated conditions of soil venting. One of the criteriafor demonstrating biodegradation is the simultaneous loss ofparent material and increase in cell biomass (Healy and Daughton,1986). While increases in microbial numbers were obtained in thepresence of surfactant 21 in the soil column experiment, no lossof parent material (JP-5) was observed. Thus, surfactant 21 didnot appear to enhance the biodegradation of JP-5 in soil columnstudies. This was unexpected based on the flask studies and thesurfactant/emulsifier screening conducted prior to the soil

22

72 .

o 5/

44

0AY 0 0D0SE 21 LOW 2.1 LOW ST 21 HIGH 21 HIGHST

NUTRIENCT AG.&R MINERAL SALTS AC-AR

FIGURE 6. MICROBIAL ENUMERATION ON NUTRIENT AGAR AND MINERALSALTS AGAR OF SOIL FROM SOIL COLUM-S AFTER 47 DAYS

OF AEROBIC INCUBATION.

23

colunu studies. The reason that surfactant 21 failed tostimulate 3P-5 biodegradation is not clear from the results of

the study. However, the possibility exists that surfactant 21.provided an alternative and preferred carbon source for microbialmetabolism, and thus inhibited the biodegradation of JP-5. Evenunder these conditions, however, decreases in JP-5 due tocometabolism should have occurred. The results of this study

suggest that surfactant-enhanced biodegradation may not be afeasible option for in situ bioremediation, or that a moreintensive screening process should be used to identifyappropriate nurfactants.

Nevertheless, the results suggest that soil venting--theprocess of aerating soils by pumping air through the soilprofile--offers an effective means for enhancing fuelbiodegradation in the vadose zone. This conclusion is based onthe decrease of JP-5 in no-surfactant control soil columns fromapproximately 150 pg/g on day 0 to approximately 20 jsg/g after 47days of soil venting. These results agree with conclusions ofothers (e.g., API, 1987) that oxygen (or some other electronacceptor) is the limiting factcr for in situ biodegradation.

24

LITERATURE CITED

API. 1987. Field study of enhanced subsurface b iodegradation ofhydrocarbons using hydrogen peroxide as an oxygen source. APIPublication No. 4448, Health and Environmental SciencesDepartment. American Petroleum Institute, Washington, D.C.

Healy, J. B. and C. G. Daughton. 1986. Issues relevant tobiodegradation of energy-related compounds in ground water.UCB/SEEHRL 86-10. U. S. Department of Energy, Bartlesville,Oklahoma. 42 pp.

Kill, I. R. 1978. Microbial transformations of pesticides, pp.137-202. In: I. R. Hill and S. J. L. Wright (ed.). PesticideMicrobiology. Academic Press, London.

Knezovich, J. P., F. L. Harrison, and R. G. Wilhelm. 1987. Thebioavailability of sediment-sorbed organic chemicals: a review.Water Air Soil Pollut. 32:233-245.

Urano, K. and M. Saito. 1985. Biodegradability of surfactantsand inhibition of surfactants to biodegradation of otherpollutants. Chemosphere 14: 1333-1342.

DISTRIBUTION r.T.Tr

AFESC / RDVS (HATHAWAY), TYNDALL AFB, FT,API / BAUMAN, WASHINGTON, DCARMY / ASST CH OF ENGRS, DAEN-ZCF, WASHINGTON, DCARMY BELVOIR R&D CEN / STRBE-AALO, FORT RETVOTR, VAARMY CERL / CERL-EN, CHAMPAIGN, ILARMY ERA / DIR, ENV QUAL, ABERDEEN PROVTNG CROUND, MDCHINFO / 01-50D, WASHINGTON, DCCORNELL UNIV / LIB, ITHACA, NYU1rRCEN / CODE 522, ANNAPOLIS, MDEPA / REG I LIE, BOSTON, MAEPA /REG II LIB, NEW YORK, NYEPA / REG III LIE, PHILADELPHIA, PAHSC/YAQE / MILLER, BROOKS AFB, TXLAWRENCE LIVERMORE NATL LAB / PLANT ENGRG LIB (L-654), LIVERMORE, CALIBRARY OF CONGRESS / SCI & TECH DIV, WASHTNCTON, DCNAS / CODE 8, PATUXENT RIVER, MIDNAS / PWO, DALLAS, TXNAS FALLON / CODE 186, FALLON, NVNAVAIRTESTCEN / PWO, PATUXENT RIVER, MDNAVFACENGCOM / CODE 09M124 (LIB), ALEXANDRIA, VANAVFACENGCOM CHESDIV / FPO-IPL, WASHINGTON, D.NAVFACENGCOM LANTDIV / LIB, NORFOLK, VANAVFACENGCOM NORTHDIV / TECH LIB, PHILADELPHTA. PANAVFACENGCOM PACDIV / LIB, PEARL HARBOR, HINAVFACENGCOM SOUTHDIV / LIB, CHARLESTON, SCNAVFACENGCOM SOUTHWESTDIV / CODE 181, SAN DIEGO, CANAVFACENGCOM WESTDIV / CODE 04A2.2 LIB, SAN BRUNO. CANAVWEAPSTAT / CODE 0923, SEAL BEACH, CANTIS / LEHMANN, SPRINGFIELD, VAOCNR / CODE 1113, ARLINGTON, VAOFFICE OF SEC OF DEFENSE / ODDR&E, WASHTNGTnN. DCPWC / CODE 134 LIB, PEARL HARBOR, HISTANFORD / MCCARTY, STANFORD, CAUNIV OF SO CALIFORNIA / HANCOCK LIB, LOS ANrFr,.S, CAUNIV OF WASH / FERGUSON, SEATTLE, WAUS EPA / GLASER, CINCINNATI, OHUSEPA / WILSON, ADA, OK

DISTRIBUTION QUESTIONNAIREThe Naval CMI Engineering Laboratory ii revising Its primary distrIbution list:.

SUBJECT CATEGORIES

1 SNORE FACILITIES 30 Atemate energy source (geothermal power, photovoftaiclA Construction methods and matenals (Including corrosion power systems, solar systems, wind systems, energy

control, coatings) storage systems)18 Waterfront structures (maintenance/detenoratlon control) 3E Sit, data and systems Integration (energy resource data.IC UtIlities (Including power condItioning) integrating energy systems)ID Explostvss safety SF EMOS design1 E Aviation EngIneering Test FacilIties 4 ENVIRONMENTAL PROTECTIONIF Fbe prevention and control dA Solid waste management1 G Antenna technology 48 Hazardous/toxic materials management114 Structural analysis and design (Including numerical and AC Waterwaste management and sanitary engineering

computer techn�ues) 40 OIl pollution remuval and recovery1J ProtectIve construction (Including hardened shelters, shock 4E Ah' pollution

and vtratlon studIes) AF Noise abatement1K SoWrock mechanics 5 OCEAN ENGINEERINGIL Akilelds and pavements SA Seafloor soils and foundationsiM Physical security SB Seafloor construction systems and operations (Including2 ADVANCED BASE AND AMPI4IEIOUS FACILITIES diver and man�ulator tools)2A Base facilIties (including shelters, power generation, water SC Undersea structures and materials

supplies) SD Anchors and moorings28 Expedient roadslairfleldsibridges 5E Undersea power systems, electromechanical cables, and20 Over-the-beach operations (including breakwaters, wave connectors

forces) SF Pressure vessel facilltles20 POL storage, transfer, and distribution SG Physical envkonment (Including sIte surveying)2E Polar engineering SN Ocean-based con�ete structures3 ENERGY/POWER GENERATiON SJ Ilyperbaric chambers3A Thermal conservation (thermal engineering of buildings. 5K Undersea cable dynamics

HVAC systems, energy loss measurement, power ARMY PEAPgeneration) BOG Shore FacilitIes

38 Controls and electrical conservation (electrical systems, NRG Energyenergy monitoring and control systems) ENV EnvronmentaldNatural Responses

3C Fuel flexibilIty (liquid fuels, coal utilization, energy from solid MGT Managementwaste) PRR PavementsRaik'oads

TYPES OP DOCUMENTS

D - Techdata Sheets; R - Technical Reports and Technical Notes; 0- NCEL. Guides and Abstracts; I - Index to TDS� U - UserGuides; 0 None - remove my name

Old Address: New Address:

relephone No.: Telephone No.:

INSTRUCTIONS

The Naval Civil Engineering Laboratory has revised its primary distribution lists. To help us verifyour records and update our data base, please do the following:

0 Add - circle number on list

* Remove my name from af your lists - check box on list

* Chango my address - add telephone number

* Number of copies should be entered after the title of the subject categoriesyou select.

0 Are we sending you the correct y of document? If not, circle the type(s) ofdocument(s) you want to receive listed on the back of this card.

Foldan fie, stape, nddrop inimM.

DEPARM84T OF THE NAVY 111Naval Cil Engrwwig LiuoryPont 1,'...*nem., CA 23043-5=00

Offioaj Swesar, e NO POS=AGIoentyloat &tvA~$uo.S NECESSARVPenalty for Pnvateo Use, S =0 IF M ARIO,.E

I iTH"

BUSINESS REPLY CARDFIRST CLASS PERMIT NO. 12503 WASH D.C.

POSTAGE WILL BE PAID BY ADDRESSEE

CODE L34 (J LEDERER)COMMANDING OFFICERNAVAL CIVIL ENGINEERING LABORATORYPORT HUENEME CA 93043-5003

NCEL DOCUMENT EVALUATION

You are number one with us; how do we rate with you?

We at NCEL want to provide you our customer the best possible reports but we need your help. Therefore, I ask youto please take the time from your busy schedule to fill out this questionnaire. Your response will assist us in providingthe best reports possible for our users. I wish to thank you in advance for your assistance. I assure you that theinformation you provide will help us to be more responsive to your future needs.

R. N. STORER. Pb.D, P.E.Technical Director

DOCUMENT NO. TITLE OF DOCUMENT_.

Date: Respondent Organization :

Name: .... ._Activity Code:Phone: Grade/Rank:

Category (pleas check)

Spoor a- User__ Proponent _ Other (Specii) ..)

Please answer on your behalf only-, not on your organization's. Please check (use an X) only the block that most closelydescribes your attitude or feeling toward that statement

SA Strongly Agree A Agree 0 Neutral D Disagree SD Strongly Disagree

SA A N D SD SA A N D SD

1. The technical quality of the report () ( ) C) ( ) () 6. The conclusions and recommenda- ( ) C) ( ) () C)is comparable to most of my other tions are clear and directly sup.sources of technical information. ported by the contents of the

report.2. The report will make significant () ( ) () () ()

improvements in the cost and or 7. The graphics, tables, and photo- ( ) C ) ( ) (performance of my operation. graphs are well done.

3. The report acknowledges related ( ) () C) () (work accomplished by others. Do you wish to continue getting r IINCEI. reports? YES NO!

4. The report is well formatted. ) () (r) YE) N)

Please add any comments (e.g.. in what ways can we5. The report is clearly written. ( ] ( ) ( ) ( ) () improve the quality of our reports?) on the back of this

form.

Comments-

Pbm Ia*1on fr. alsid .

DEPARTMENT OF THE NAVY 111Navl CMI Etmwq LabratoryPon l4ueemm. CA 93043-S003

Offloia susk"SesPwnWy for Pttate Ue S300

Code L03BNAVAL CIVIL ENGINEERING LABORATORY

PORT HUENEME, CA 93043-5003