Treatment of OBM Drill Cuttings Soil by Elimination of Biodegradation Limiting Factors using Bio-augmented Landfarming 

S. M. Afifi, Director of Environmental Division, United Environmental, Inc. (Middle East Division), 35 Salah Salem, Cairo, Egypt, Tel: 0020-2-4044189, Fax: 0020-2-4048366, Email: united@unitedenv.com
J. W. Warner, Professor of Civil Engineering, Colorado State University, Ft. Collins, CO 80523, Tel: 970-491 8655

During the drilling of oil wells at the Egyptian western desert, oil based drill cuttings have been produced.  Though the quantity of drill cuttings produced per well is not large, collectively, through out the oil and gas industry, the quantity of these drill cuttings is very significant and represents a major disposal problem for the oil and gas industry world wide. These drill cuttings are in the range of 40 to 70 percent by volume petroleum hydrocarbons in the diesel range (C12-C18). The drill cuttings have the physical appearance of being pitch black, sticky with a clayey texture.  These drill cuttings are completely saturated with petroleum hydrocarbons and liquid oil readily drains from the cuttings.

Bioremediation is commonly accepted as the most efficient, environmentally safe and cost effective method for treatment of the drill cuttings. This paper discusses the conducted project for treating the petroleum hydrocarbons based drill cuttings utilizing landfarming enhanced by bioaugmentation and biostimulation additives.  The rate of bioremediation of petroleum hydrocarbons was sensitive to many factors such as the chemical composition of the petroleum hydrocarbons, presence of suitable microbes, soil moisture conditions, water quality, availability of suitable electron acceptors, nutrients (NPK), enzymes, temperature etc.

The soil was analyzed for the presence of indigenous microbes and soil nutrients (NPK).  Both were lacking at the western desert site and the bioremediation process has been bioaugmented and biostimulated by the addition of hydrocarbon consuming microbes and with NPK.  A proprietary mixture of bio-enhancers has also been used.  This paper presents the taken steps to eliminate the biodegradation limiting factors.  Charts of TPH concentration with time are presented. Over approximately 1 year of operation the overall degradation rate has been 524 mg/kg/day.  In comparison with biodegradation rates reported in the literature for other sites, this is an excellent rate for biodegradation.

Co-Composting of Creosote-Contaminated Soil with Cattle Manure and Vegetable Waste for the Biodegradation of Creosote in Soil

Harrison I. Atagana, School of Earth Sciences, Mangosuthu Technikon, P.O. Box 12363, Jacobs, Durban 4026, South Africa, Tel. +27 31 907 7477, Fax. +27 31 907 2892, Email: atagana@yahoo.com
RJ Haynes, School of Applied Environmental Sciences, University of Natal, Pietermaritzburg 3209, South Africa, Tel. +27 33 260 5111
FM Wallis, School of Applied Environmental Sciences, University of Natal, Pietermaritzburg 3209, South Africa, Tel. +27 33 260 5111

Co-composting of mispah form (FAO: Lithosol) soil contaminated with >380 000mg kg^-1  was carried out separately with cattle manure and mixed vegetable waste for a period of 19 months. The soil was mixed in a ratio of 1:1 (v/v) with wood chips to improve aeration. The soil-wood chips mixture was then mixed in a ratio of 4 soil-wood chips mixture : 1 compost material (cattle manure or mixed vegetable waste). Duplicate compost heaps were set up on wood palettes overlaid with double layers of nylon straw bags. Moisture, temperature, pH, ash content, C:N ratio of the compost and the creosote concentration of the soil was monitored monthly. The concentration of selected creosote components in the soil was also determined at the end of the incubation period. Temperature was observed to rise to about 40^OC in the cattle manure within two months of incubation while temperature in the control and vegetable waste remained below 30^OC until the fourth month. Creosote concentration in the control was reduced by 17% at the end of the incubation period while concentration of creosote in the cattle manure and vegetable waste compost was reduced by 98% and 97% respectively. The percentage rate of creosote reduction in the mixed vegetable compost was initially lower than observed in the cattle manure compost. However, the reduction rate became similar in the third month. The difference in the rate of reduction in the subsequent months became smaller until the end of the incubation. The concentrations of selected creosote components were reduced by between 96% and 100% within the same period. There was no significant difference between the level of reduction in creosote concentration in the cattle manure and the vegetable waste compost at p 0.05. Microbial respiration experiments and plate counts of microorganisms show that as microbial population and respiration increased or decreased, percentage reduction in creosote concentration increased or decreased.  

Bioremediation of Polyaromatic Hydrocarbons Using a Groundwater Recirculating Treatment System

Peter J. Cagnetta, Science Applications International Corporation, 6310 Allentown Boulevard, Harrisburg, PA  17112, Tel: 717-901-8841, Email: peter.j.cagnetta@saic.com
Daniel B. Lewis, Spotts, Stevens, and McCoy, Inc., 345 North Wyomissing Boulevard, P.O. Box 6307, Reading, PA  19610, Tel: 610-376-6581, Email: dan.lewis@ssmgtroup.com

Releases from a No. 2 fuel oil UST and a motor oil UST resulted in the groundwater being impacted with fluorene, phenanthrene, and pyrene at a site in Reading, Pennsylvania.  The groundwater is presently at approximately 11 feet  below grade and occurs within the interbedded limestone and dolomite underlying the site. 

A remedial options assessment (ROA) identified that natural biodegradation of the hydrocarbons was occurring.  In order to maximize the biodegradation rate, a treatment system was designed and constructed which included one extraction well in the former UST area and four injection wells located along the downgradient and side-gradient edges of the plume.  Water was extracted from the well at 5 gpm and treated with granular-activated carbon, amended with atmospheric oxygen, and amended with ammonium phosphate fertilizer.  The amended water was then injected into 4 injection wells at 1.25 gpm per well.  The closed loop recirculation approach ensured the maximum mixing of contaminants, amendments, and indigenous bacteria. 

Throughout the first 80 days of operation, the concentrations of fluorene in well MW‑3 declined from 466 micrograms per liter (mg/l) to <10 mg/l.  During the same time period, the pyrene concentration declined from 78 mg/l to <10 mg/l.  The concentration of phenanthrene in well MW‑3 declined from 1,232 mg/l to <10 mg/l after 238 days.  The decay rates were calculated at 5.69, 1.09, and 0.07 mg/l per day for fluorene, pyrene, and phenanthrene, respectively. 

Prior to the start-up of the treatment system, the groundwater at well MW‑3 contained a fluorene‑degrading microbial population and a pyrene‑degrading population of 1,414 MPN/ml and 1,000 MPN/ml respectively.  After 78 days of operation, each population increased to over 20,000 MPN/ml and, subsequently after 160 days operation, declined to <500 MPN/ml.  The contaminant-degrading populations were stimulated by the addition of the amendments and then subsequently declined as the concentrations of contaminants or growth substrate declined.

The concentration of dissolved oxygen throughout the plume prior to the start-up of the treatment system was <2  mg/l.  After start-up and operation of the system, the dissolved oxygen ranged from 6 to 10 mg/l throughout the 12 months of operation.

Stimulation of Environment-Polluting Oil Residues Degradation by Microbial Associations

Anca Voicu, Institute of Biology of Romanian Academy, Spl. Independentei 296, CP 56-53, sector 6, 79651 Bucharest, Romania, Tel: 401-2239072, Fax: 401-2219071, Email: avoic@ibiol.ro
Smaranda  Dobrota, Institute of Biology of Romanian Academy, Spl. Independentei 296, CP 56-53, sector 6, 79651 Bucharest, Romania, Tel: 401-2239072, Fax: 401-2219071, Email: sdobr@ibiol.ro
Ioana G. Petrisor, University of Southern California, Dept of Civil and Environmental Engineering, 3620 S. Vermont Ave., KAP 210 – MC 2531, Los Angeles, CA 90089-2531, Tel: 213-740-0594, Fax: 213-744-1426, Email: petrisor@usc.edu
Mugur Stefanescu, Institute of Biology of Romanian Academy, Spl. Independentei 296, CP 56-53, sector 6, 79651 Bucharest, Romania, Tel: 401-2239072, Fax: 401-2219071, Email: mstef@ibiol.ro
Mihaela Lazaroaie, Institute of Biology of Romanian Academy, Spl. Independentei 296, CP 56-53, sector 6, 79651 Bucharest, Romania, Tel: 401-2239072, Fax: 401-2219071, Email: mlaza@ibiol.ro
Ioan I. Lazar, Institute of Biology of Romanian Academy, Spl. Independentei 296, CP 56-53, sector 6, 79651 Bucharest, Romania, Tel: 401-2239072, Fax: 401-2219071, Email: petad@fx.ro
J. Michael Kuperberg, Institute for International Cooperative Environmental Research, Florida State University, 226 Morgan Building, 2035 East Paul Dirac Drive, Tallahassee, FL 32310-3700, Tel: 850-644-5524, Fax: 850-574-6704, Email: mkupe@mailer.fsu.edu

Oil production and processing activities have generated complex pollution problems all over the world. Romania, a country with long history of oil industry is faced today with severe hydrocarbon pollution, affecting both surface and underground environments. This paper presents investigations on crude oil degradation efficiency of 23 hydrocarbon-oxidant microorganisms, isolated from terrestrial and aquatic environments contaminated by oil residues, from a Romanian oil field. The hydrocarbon-oxidant microorganisms under study were represented by 3 yeast strains and 20 microbial strains belonging to the genera: Bacillus, Pseudomonas, Arthrobacter, Corynebacterium, Serratia, Micrococcus. These microorganisms were used individually, in pure culture, as well as in different associations. It was studied and put in evidence the capacity of the 23 isolated microorganisms to produce biosurfactants and biosolvents, as well as to emulsify monoaromatic hydrocarbons and waxy-paraffinic crude oil. The best results concerning all studied parameters, including crude oil degradation, were obtained for several microbial associations, selected for field bioremediation deployments.

Stimulating Simultaneous Anaerobic Oxidation of BTEX and Reductive Dechlorination of Chloroethenes in Groundwater

Pawan K. Sharma, Camp Dresser & McKee Inc., 100 Pringle Avenue, Suite 300, Walnut Creek, CA  94596, Tel: 925-296-8054, Fax: 925-933-4174, Email: sharmapk@cdm.com    
Dalia Hildebrand, Camp Dresser & McKee Inc., 100 Pringle Avenue, Suite 300, Walnut Creek, CA  94596, Tel: 925-296-8053, Fax: 925-933-4174, Email: hildebrandds@cdm.com  

This presentation documents the results of a field application in which sodium lactate was injected into a mixed organic groundwater plume.  The intent of the sodium lactate injections was to produce dissolved molecular hydrogen in groundwater.  The hydrogen would serve as the electron donor in microbially facilitated reduction-oxidation (redox) reactions.  The microbes would preferentially reduce the concentrations of nitrate, manganese, iron, sulfate, and other completing electron acceptors, with respect to chloroethenes.  With chloroethenes as the favored electron acceptors and the consumption of the injected lactate, the benzene, toluene, ethyl benzene, and xylenes (BTEX) compounds would serve as the electron donor in the redox reactions.  Within six weeks after the lactate injections, groundwater nitrate, manganese, iron, sulfate levels were reduced to levels that allowed the chloroethenes to be favored electron acceptors.  Eight months after the injections, total BTEX concentrations have decreased from 11,310 to 2,028 ug/L.  In the last sampling event all individual BTEX compound concentrations were below State of California Maximum Contaminant Levels (MCLs). During this eight month period, trichloroethene (TCE) concentration has decreased from 6,200 to 2,000 ug/L and cis-1,2-dichloroethene (DCE) concentration increased from 3,700 to 4,200 and as ultimately decreased to 2,300 ug/L.  During this same time, trans-1,2-DCE concentration also increased from 1,800 to 2,600 and then decreased to 1,000 ug/L.  Vinyl chloride has not been detected.  Anaerobic oxidization of DCE is being evaluated as a possible pathway for the DCE concentration decreases.  With the consumption of the injected lactate in the groundwater and the continued low competing electron acceptor concentrations, it is expected that microbes will continue to biodegrade the BTEX compounds through anaerobic oxidation with chloroethenes and carbon dioxide serving as the favored electron acceptors.

Microbial Degradation of Detoxification Products from Chemical Warfare Agents Destruction and Organophosphorus Herbicides

Ivan I. Starovoitov and Inna T. Ermakova, G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms RAS, 142290 Pushchino, Moscow region, Russia
Gennady A. Zharikov, Research Centre for Toxicology and Hygienic Regulations of Biopreparations, 142253 Serpukhov, Moscow region, Russia

In keeping with  the 1993 Paris Chemical Weapons Convention, methods are being developed  to create technologies for Chemical Warfare (CW) agents destruction. The main problem of CW agents destruction is providing environmental safety. Biotechnological approach for destruction of xenobiotics is considered as the most promissing to provide environmental safety.

In course of joint studies with scientists of Texas A&M University (USA)  an integrated chemical/biotechnological method has been developed to create an environmental safe technology for destruction of the detoxification products of mustard-lewisite mixture (MLM). This method includes three sequential steps: (1) detoxification of MLM by alkaline hydrolysis, (2) electrochemical treatment of detoxification products including electrolysis for converting all organic substances to bioutilized   compounds and electrocoagulation for removing arsenic salts, and (3) bioutilization of the electrochemical products by microorganisms.

Another approach was developed for destruction of thiodiglycol (TDG), the main product of “mustard gas” (HD) detoxification. Microbial cultures Alcaligenes xylosoxydans subsp. denitrificans, possessing the degrading activity against TDG was isolated from the soil samples contaminated by the products of HD detoxification and the most active strain A. xylosoxydans TD2  was selected. The effect of  different cultivation  conditions on the efficiency of TDG biodegradation was determined. The scheme for TDG metabolism by A. xylosoxydans TD2  was suggested.

For biodegradation of alkylphosphonic  acids, the end products of chemical hydrolysis of neurotoxic CW agents,  bacterial strains were isolated and selected. These strains are able to biodegrade alkylphosphonates in concentration up to 25 mM during 72 hrs. Dynamics of the growth  of  these strains in the medium with alkylphosphonates was studied. Some of these strains are able to biodegrade organophosphorus herbicide, glyphosate, in concentration up to 20 mM during 120 hrs. Such strains may be useful for development of technology for bioremediation of soils and water, polluted by  organophosphorus compounds.

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