Sara Cuadros-Orellana, Instituto de Tecnologia e Pesquisa, Universidade Tiradentes, Aracaju – SE, Brazil
Metchild Pohlschröder, Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA, USA
Maricy Bonfá and Lucia R. Durrant, Departamento de Ciência de Alimentos, FEA, Universidade Estadual de Campinas, Campinas, SP, Brazil

Produced water is salty wastewater that is produced in conjunction with oil or natural gas. For every barrel of oil produced, approximately 10 barrels of brackish or saline water is generated. Presently over 5 billion gallons a day of produced water is generated in the US. The saline content is high and the organic composition is very complex, varying widely in concentration, these constituents include salt (1,000 to 250,000 ppm), hydrocarbons, and, in some cases, heavy metals and trace elements. Thus, the treatment and disposal of produced waters is a challenging task, since the impact and toxicity on soils, vegetation, surface water and shallow ground water is high. The goal of this work was the isolation of halophilic archaea able to degrade hydrocarbons to be used in the treatment of produced water. Six hypersaline sites were tested for the presence of halophilic archaea able to metabolize aromatic compounds: the Uyuni Salt Marsh (Bolivia), the sabkhas in the Persian Gulf (Saudi Arabia), the Dead Sea (Israel and Jordan), and the crystallizer ponds in Cahuil (Chile), in Cabo Rojo (Puerto Rico), and in Segipe (Brazil).The strategy used for the enrichment and isolation of halophilic archaea able to grow in aromatic compounds was successful. Twelve strains able to grow in 1,2-benzoantracene  (2 mM) and 44 strains able to  grow  in p-hydroxybenzoic acid  (10 mM) as the sole carbon and energy source were isolated. Strain MM17, isolated from a Dead Sea water sample, showed the best growth and was able to degrade benzoic (10 mM) and p-hydroxybenzoic (10 mM) acids after 200 h of cultivation. Biochemical and genetic analyses of the isolates, together with the analysis of polar lipid profiles, indicate that the strains belong to at least two different genera: Haloferax and Halobacterium. These strains are now being used on biodegradation studies of hydrocarbons in produced waters.

Acknowledgements: We thank FAPESP (Brazil), (CAPES, Brazil) and NSF (USA) for financial support.

Degradation of Hydrocarbons by Bacteria Isolated from Oil-Contaminated Sites

R Lima, FB Dias and LR Durrant, Departamento de Ciências de Alimentos – Faculdade de Engenharia de Alimentos (FEA), Universidade Estadual de Campinas (UNICAMP) Cx. Postal: 6121, CEP: 13083-862 Phone: +55 19 37882172, Email: durrant@fea.unicamp.br

Crude oil contains mutagenic, carcinogenic, growth inhibitory compounds, which can cause severe damage to aquatic and terrestrial environment.  It is estimated that 0.08–0.46% of the total oil production is wasted to the environment, eventually causing pollution to waters and shores. Several petroleum aliphatic and polycyclic aromatic hydrocarbons (PAHs) can act as source of carbon and energy for the growth of microorganisms. (PAHs) are relatively resistant to biodegradation and can therefore accumulate to substantial levels in the environment. Since some of the larger species are carcinogenic, they can present a significant health hazard. Bacterial strains were isolated from soil samples contaminated with petroleum derivatives collected near Paulinia's petroleum refinery in Campinas (SP, Brazil). They were cultivated for 12 days at 30º C and 150 rpm, in a medium containing minerals and 0.05% (final concentration) of one of the following hydrocarbons: tridecane, tetradecane, pristine, hexadecane, phenyldecane, phenanthrene, naphthalene, pyrene and benzo[a]pyrene.  The production of biosurfactants, via the determination of emulsification activities and reduction of surface tension, toxicity of the supernatants and also degradation of the hydrocarbons via gas chromatography were determined following growth of the bacteria. A Bacillus sp degraded up to 90% of the hydrocarbons present in the medium and toxicity (CE ₅₀= 4.90%), which was the second lowest among all the strains tested. It was also able to reduce the surface tension and produce some emulsification activity. A  Enterobacter aerogenes strain degraded up to 83% of all the hydrocarbons present in growth medium and produced the lowest toxicity (CE ₅₀= 13.10%), and was also able to reduce the surface tension of the culture medium. The ability to produce surface active agents, which help the uptake of insoluble substrates, to degrade various aliphatic and aromatic hydrocarbons, suggest that these strains have potential to be applied in bioremediation of petroleum contaminated sites.

We acknowledge financial support from FAPESP-SP, BRAZIL.

Degradation of Low and High Molecular Weight PAHs by Soil Fungi under Microaerophilic and Anaerobic Conditions

IS Silva and LR Durrant, Departamento de Ciências de Alimentos – Faculdade de Engenharia de Alimentos (FEA), Universidade Estadual de Campinas (UNICAMP) Cx. Postal: 6121, CEP: 13083-862 Phone: +55-19-37882172, Email: durrant@fea.unicamp.br

Polycyclic aromatic hydrocarbons (PAHs) are pollutants originated from incomplete combustion of organic matter and fossil fuels or accidental spills during petroleum transportation. These recalcitrant compounds can be carcinogenic and constitute risk for human health. Ligninolytic fungi are natural degraders of lignin, and can also degrade structurally related compounds such as PAHs and other aromatic compounds due to the action of unspecific enzymatic system composed of peroxidases and phenoloxidases, such as Lignin-Peroxidase (LiP), Manganese–Peroxidase (MnP), Laccase (Lac) and Tyrosinase (Tyr). Degradation of PAHs by microorganisms is hindered under low oxygen levels or anaerobic conditions since the absence of oxygen inhibits primary cleavages of the aromatic compounds. In this work the ability of five ligninolytic soil fungi to degrade various molecular weight PAHs (by HPLC), was determined during a 30-day period under microaerophilic and anaerobic conditions. The ligninolytic enzymes produced were also investigated. Naphthalene and phenanthrene (0.5%wt/vol), crysene, perylene, naphtol [2,3-a] pyrene and decacyclene (0.05%wt/vol) were used as carbon sources in a medium containing minerals, vitamins and an oxygen-reducing system (L-cysteine-hydrochloride and resazurin). The inoculated Erlenmeyer flasks were placed into hermetic jars containing MicroaerobacÒ or AnaerobacÒ plates and incubated at 30°C. Under microaerophilic conditions, laccase activities were more frequent in the medium containing naphthalene and phenanthrene; and LiP activities on decacyclene. The highest values of MnP (11 - 28 U/L.min^-1) were detected on perylene. Aspergillus sp was able to degrade all the PAHs used (25 - 46.5%). Achremonium sp was the best degrader of the low molecular weight  (LMW) PAHs: naphthalene (32%) and phenanthrene (20%). Verticillum sp showed the greatest degradation of the HMW PAHs: crysene (30%), perylene (25%), naphtol [2,3-a] pyrene (40.5%), and decacyclene (37%). Under anaerobic conditions, maximal laccase activities (0.16 - 0.54 U/L.min^-1),  were detected on the 30^th day for the HMW PAHs. Trichocladium canadensis was capable to degrade all PAHs (10 - 22.1%). Strain H2 (an unidentified basidiomycete strain), showed best degradation for naphthalene (19.7%), perylene (17.9%) and naphtol [2,3-a] pyrene (12.4%). These results indicate that ligninolytic soil fungi can degrade PAHs under low oxygenation conditions or in the absence of oxygen, and that their ligninolytic enzymes are produced under such conditions and may be involved in the degradation of PAHs.

Acknowledgment: We thank CNPq (Brazil) for financial support.

Initial Site Assessment for Dehalococcoides using PCR and Ethene Concentrations: Comparison with Microcosm Results

Samuel Fogel, Bioremediation Consulting Inc., 39 Clarendon Street, Watertown, MA 02472, Tel: 617-923-0976, Fax 617-923-0959, Email: sfogel@bciLabs.com
Margaret Findlay, Bioremediation Consulting Inc., 39 Clarendon Street, Watertown, MA 02472, Tel: 617-923-0976, Fax 617-923-0959, Email: mfindlay@bciLabs.com
Donna Smoler, Bioremediation Consulting Inc., 39 Clarendon Street, Watertown, MA 02472, Tel: 617-923-0976, Fax 617-923-0959, Email: dsmoler@bciLabs.com
Sami Fam, Innovative Engineering Solutions Inc., 89 Access Rd, Suite 28A, Norwood, MA 02062, Tel: 781-255-0796, Fax 781-255-7421, Email: s.fam@iesionline.com

The initial evaluation of the bioremediation potential of twenty sites contaminated with chlorinated ethenes and ethanes are being conducted by evaluating the results (for several wells from each site) for three sources of information; (1) the ethene concentration in groundwater samples, (2) the presence of DNA from Dehalococcoides ethenogenes by genetic testing using PCR, and (3) microcosm tests with added electron donor, conducted to measure dechlorination of the site contaminants in site groundwater.  The sites tested were contaminated by historic releases of industrial chemicals including PCE (tetrachloroethene) and its daughter products, as well as other chlorinated compounds.

Results indicate a strong, but not absolute, correlation between negative PCR results for a well and lack of ethene in the groundwater from that well.  For 25 PCR-negative wells from 13 sites, 23 had ethene concentrations less than 0.3 ppb, and 2 had ethene between 6 and 18 ppb.  In cases which may arise in which PCR results are positive and microcosm results are negative, it would be concluded that the PCR test is reporting non-viable DNA, indicating that the organisms were previously active, but that changing site conditions have reduced their viability.

For sites having some locations without native dechlorinators, and other locations with native dechlorinators, additional microcosm tests have been useful in designing strategies for intra-site bioaugmentation.  For those sites having all wells negative for both microcosm and PCR, additional detailed microcosm tests have been employed to design the strategy for site modification and bioaugmentation with laboratory-grown dechlorinating cultures.  

Use of Chitosan as an Alternative Material for Immobilization of Microorganism

Chih Huang and Shuman Lin, Sinotech Engineering Consultants, Inc., 3F, No. 248, An-Kang Rd., Nei-Hu, Taipei, TAIWAN, R.O.C., Tel: 886-2-27918858, Fax: 886-2-27941354, Email: chih@sinotech.org.tw
Tsair-Fuh Lin and Yen-Min Chen, National Cheng-Kung University, No. 1 Da-Shue Rd., Tainan, TAIWAN, R.O.C., Tel: 886-6-2364455, Email: tflin@mail.ncku.edu.tw
Jui-Che Lin and Fong-Ming Shieh, National Cheng-Kung University, No. 1 Da-Shue Rd., Tainan, TAIWAN, R.O.C., Tel: 886-6-2757575 Ext. 62665, Email: jclin@mail.ncku.edu.tw

Immobilization of organism technique has been used in wastewater treatment for decades to achieve high biomass level, which results in high rate of contaminant degradation. Recently, a similar approach has been proposed for groundwater remediation. The proposed biological permeable barrier uses biocarrier as the reactive material instead of zero valent iron to degrade organic contaminants. While the technique is widely used for environmental issues, traditional materials (e.g., PVA and PEG) are non-biodegradable and require post treatment or disposal after replacement.  In particular, replacing the reactive material in permeable barriers is costive and time consuming. Thus, developing an alternative biocarrier, which can be biodegraded and

refilled instead of replaced, would be vital to environmental applications, especially for permeable barriers. In this study, pseudomonas putida was encapsulated or immobilized with chitosan which is a naturally existing polymer and the efficiency in degrading phenol and cometabolizing trichloroethene (TCE) were tested. The mechanical strength of the chitosan beads was modified by choosing different crosslinking agents and by adjusting several parameters during the making process.  The chitosan beads can sustain for months in column tests without obvious structural breakdown. In batch tests, the acclaimed chitosan beads can remove 99% of phenol at phenol initial concentrations ranging from 100 to 1000 mg/L.  Similar tests for cometabolism of trichloroethene showed 50 to 80% removal at TCE initial concentrations ranging from 100 to 1000 mg/L. However, the pH value of the batch systems was found to be critical to the effectiveness of biodegradation. Presumably, the influence of pH is due to the neutralization of surface charge of the beads. A sequential acclaiming procedure is being investigated to further improve the effectiveness and a pilot site is being setup for testing the applicability to the permeable barrier.

Accelerated Bioremediation with Oxygen Release Compound-Advanced (ORC-Advanced^TM):  Evolution of Time-Release Electron Acceptors

Stephen S. Koenigsberg, Regenesis, 1011 Calle Sombra, San Clemente, CA  92673; Tel: 949-366-8000, Fax: 949-366-8090, Email: skoenigsberg@regenesis.com
Anna Willett, Regenesis, 1011 Calle Sombra, San Clemente, CA  92673; Tel: 949-366-8000, Fax: 949-366-8090, Email: awillett@regenesis.com
Michelle Von Arb, Regenesis, 1011 Calle Sombra, San Clemente, CA  92673; Tel: 949-366-8000, Fax: 949-366-8090, Email: mvonarb@regenesis.com

Oxygen is typically the limiting substrate for microbes capable of aerobically biodegrading contaminants, such as petroleum hydrocarbons, gasoline oxygenates, and certain chlorinated solvent daughter products.  Without adequate oxygen, contaminant degradation will either cease or will proceed by a much slower anaerobic rate.  Oxygen Release Compound-Advanced (ORC-Advanced^TM) is a state-of-the-art solid oxygen source for stimulating in situ aerobic bioremediation.  ORC-Advanced is white powder composed of a proprietary, high oxygen-yielding calcium oxyhydroxide compound.  When hydrated, ORC-Advanced is designed to release its full amount of oxygen (17% by weight) consistently over a 12 month period.  This process enables aerobic microbes to significantly accelerate rates of bioremediation over longer periods of time. 

ORC-Advanced is a proprietary formulation of calcium oxyhydroxide, and, as shown next, releases oxygen and forms simple calcium hydroxide as a by product.

CaO(OH)² + H₂O à ½ O₂ + Ca(OH)^{2 +} H₂O

ORC-Advanced has been engineered with Controlled Release Technology (CRTTM), which retards the hydration of the calcium oxyhydroxide crystal and slows the formation oxygen in and its release from the crystal structure.  The CRT chemistry prevents premature and rapid release of oxygen that can lead to uncontrolled bubbling and oxygen waste via “blow off” prior to injection into a contaminated aquifer.  CRT involves the intercalation (permeation) of phosphate into the crystalline structure of calcium oxyhydroxide.

ORC-Advanced has been tested in the laboratory for oxygen release characteristics and has been injected for aerobic bioremediation at several field sites.  This presentation will discuss the chemistry of ORC-Advanced and show laboratory and field results.

Applications of Hydrogen Release Compound (HRC^®) for Accelerated Bioremediation

Stephen S. Koenigsberg, Regenesis, 1011 Calle Sombra, San Clemente, CA  92673, Tel: 949-366-8000, Fax: (949) 366-8090, Email: skoenigsberg@regenesis.com
Anna Willett, Regenesis, 1011 Calle Sombra, San Clemente, CA  92673, Tel: (949) 366-8000, Fax: (949) 366-8090, Email: awillett@regenesis.com

Hydrogen Release Compound (HRC^â) is a food-grade, polylactate ester that, upon being deposited into an aquifer, slowly releases lactic acid for 12 to 18 months, creating the anaerobic conditions necessary for biodegradation of chlorinated solvents and many other contaminants.  Fermentation of lactic acid from HRC by native bacteria produces a series of organic acids and results in the production of molecular hydrogen.  Molecular hydrogen is an extremely efficient electron donor for a wide range of reductive biodegradation processes.  The material is applied to the aquifer by push-point injection or backfill-auguring and can be applied in grid, barrier, or excavation formats.  HRC is typically recommended for treatment of chlorinated solvent contamination found in the dissolved phase or sorbed to saturated soil.  However, bioremediation can facilitate removal of residual source or DNAPL material at some sites.  In addition to chlorinated solvent biodegradation, HRC has been used for bioremediation of explosives, perchlorate, chlorinated pesticides, and nitrate.  HRC has been applied over 600 times since 1997, making it the most widely-used electron donor for accelerating bioremediation.  This presentation will give case histories and discussions of lessons learned.

Microbial Dechlorination of Polychlorinated Dibenzo-p-dioxin/furan Congeners by a Dehalococcoides Containing Culture

Fang Liu, Department of Environmental Sciences, Rutgers University, New Brunswick, NJ, 08854, Tel: 732-932-4961, Fax: 732-932-8644, Email: fangliu@eden.rutgers.edu
Donna E. Fennell, Department of Environmental Sciences, Rutgers University, New Brunswick, NJ, 08854, Tel: 732-932-8750, Fax: 732-932-8644, Email: fennell@envsci.rutgers.edu

Dehalococcoides ethenogenes strain 195 dechlorinates chloroethenes and a variety of chlorinated aromatic compounds, including 1,2,3,4-tetrachlorodibenzo-p-dioxin (1,2,3,4-TeCDD). The ability of D. ethenogenes strain 195 to dechlorinate different polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) congeners was investigated.  Dechlorination of 1,2,3,4-TeCDD, octachlorodibenzo-p-dioxin (OCDD) and 1,2,3,4,7,8-hexachlorodibenzofuran (1,2,3,4,7,8-HxCDF) was examined in a  mixed culture containing D. ethenogenes strain 195. An individual PCDD/F congener served as a sole electron acceptor in one triplicate bottle set while tetrachloroethene (PCE) and 1,2,3,4-tetrachlorobenzene (TeCB) were added as growth co-substrates along with the PCDD/F congener in another two sets of triplicate bottles. 1,2,3,4-TeCDD was added at 31µM. OCDD and 1,2,3,4,7,8-HxCDF were added at 5 µM. PCE and TeCB were added at 25 µM. Butyrate (0.1 mM) was added as an electron donor periodically.  The mixed culture dechlorinated 1,2,3,4-TeCDD at similar rates both with and without the addition of PCE in original fully-grown cultures and in the first generation transfer bottles which received 10 % v/v inoculum.  A pentachlorodibenzofuran congener was detected in all three sets of HxCDF-amended cultures within 1 month. Cultures with TeCB as co-substrate exhibited the most extensive HxCDF dechlorination with production of a tetrachlorodibenzofuran congener within 2 months. No dechlorination products were observed from OCDD within the same time period.  The results suggest that PCE co-amendment is not needed to sustain 1,2,3,4-TeCDD dechlorination.  Furthermore, D. ethenogenes strain 195 could dechlorinate a PCDF congener containing chlorines on both rings.  This suggests that this strain may have utility in dechlorinating environmentally relevant PCDD/F congeners. 

Microbial Degradation and Utilization of Sugar Industry Wastes

S. Sridharan, Center for Research and P.G. Dept. of Botany, Thiagarajar College, Madurai, Tamilnadu, India

The major purpose of this project work was to analyze and assess the microbial degradation of sugar industry wastes and to solve the problem of waste disposal. The sugar industry wastes contained organic pollutants with high molecular weights and complex structures that were not easily hydrolyzed. In the present study it was found that there is feasibility to treat sugar industry wastes with fungi and bacteria. Spores of three fungal species Phanerochaete crysosporium, Trichoderma viride and that of Aspergillus fumigatus isolated from sugar industry effluent were used for inoculation. The amount of suspended solids, COD, BOD, starch and reducing sugars were measured. Colour of the fermented sugar wastes decreased gradually in all the trials, with Trichoderma viride showing maximum colour removal on the eighth day. Suspended solids marginally increased in A.fumigatus. T.viride was the most efficient in COD removal. The BOD of the sample increased in all the experiments. It was also found that it is possible to treat sugar industry wastes with anaerobic bacteria. The sugar wastes when treated with bacteria after acclimation and with careful pH monitoring increased the degradation. It was found to remove 62% with an influent COD of 7200 mg/l and a volumetric loading of 2.1Kg COD m³/d. The efficiency was seen to increased when large amount of activated sludge was maintained. The present study clearly brought out the efficiency of microbes in waste degradation and utilization.

Efficacy of Bioremediation with Hydrogen Release Compound (HRC®) as a Replacement for a Pump and Treat System

Michelle Von Arb, Regenesis, 1011 Calle Sombra, San Clemente, CA  92673; Tel: 949-366-8000, Fax: 949-366-8090, Email: mvonarb@regenesis.com
Anna Willett, Regenesis, 1011 Calle Sombra, San Clemente, CA  92673; Tel: 949-366-8000, Fax: 949-366-8090, Email: awillett@regenesis.com
Stephen S. Koenigsberg, Regenesis, 1011 Calle Sombra, San Clemente, CA  92673; Tel: 949-366-8000, Fax: 949-366-8090, Email: skoenigsberg@regenesis.com

A pump and treat system was installed in 1985 at a chlorinated ethene contaminated industrial site in California. However, after eleven years of operation, the removal of chlorinated ethenes from groundwater was no longer cost effective.  Bioremediation with Hydrogen Release Compound (HRCÒ) was chosen to replace the pump and treat system, with the intent of cost-effectively accelerating the natural attenuation of the remaining chlorinated ethene contamination. 

HRC is a polylactate ester that, upon hydration or microbial cleavage of its ester bonds, slowly releases lactate.  Lactate serves as an electron donor and carbon source for microbial reductive biodegradation.  HRC is a viscous, amber-colored liquid that is typically injected into a contaminated aquifer using direct push technology or backfill injection via a hollow stem auger.  Once in place, HRC creates a plume of lactate and its fermentation products (dissolved hydrogen and other organic acids) downgradient of the injection area and serves to accelerate the anaerobic bioremediation processes that transform chlorinated ethenes to innocuous daughter products, like ethene. 

At the California site, tetrachloroethene (PCE) and trichloroethene (TCE) concentrations were reduced by over 97% and 98% respectively in the HRC impacted wells. In a well located in the HRC injection grid, contaminants included TCE, cis-1,2-DCE (dichloroethene), and VC (vinyl chloride). Following the cessation of pumping, concentrations of chlorinated ethenes spiked to elevated levels in this well; however, the subsequent HRC application resulted in the reduction of all chlorinated species.  For example, TCE was reduced from 480 ug/L to 4.4 ug/L, which is below the federal TCE MCL of 5 ug/L.  Complete reductive dechlorination was achieved, with production of 280 ug/L of ethene.  Replacement of the pump and treat system with bioremediation not only resulted in the reduction of contaminant concentrations, but a 75% decrease in annual remediation costs.  This presentation will give a detailed site analysis, including product performance results and costs.

Rapid Biological Treatment of Residual DNAPL with Slow Release Electron Donor HRC-X^®

Anna Willett; Regenesis, 1011 Calle Sombra, San Clemente, CA  92673; Tel: (949) 366-8000, Fax: (949) 366-8090, Email: awillett@regenesis.com
Stephen S. Koenigsberg, Regenesis, 1011 Calle Sombra, San Clemente, CA  92673; Tel: (949) 366-8000, Fax: (949) 366-8090, Email: skoenigsberg@regenesis.com

The use of in situ bioremediation to stimulate the rapid dissolution, desorption, and biodegradation of residual DNAPL has been demonstrated in the laboratory and in well-documented field studies.  Biodegradation of dissolved-phase contaminants increases the partitioning and subsequent biodegradation of residual DNAPL to the aqueous phase by (1) increasing the concentration gradient and driving force for dissolution and desorption and (2) increasing the overall solubility of the DNAPL by production of hydrophilic daughter products. 

Specifically, the application of the slow release electron donor substrate, Hydrogen Release Compound-Extended Release (HRC-X®), has been successful in remediating high concentrations (>100 mg/L) of chlorinated ethenes, like PCE and TCE in residual DNAPL environments.  In situ bioremediation with HRC-X is a low-cost method for residual DNAPL removal and avoids the costly and lengthy assessment associated with defining the exact location of the dispersed residual DNAPL.

HRC-X is a highly concentrated electron donor for bioremediation and has a field longevity of at least 3 years, as verified by field measurements of lactate and its derivative organic acids.  Injection of HRC-X directly into the general residual DNAPL area of a contaminated aquifer results in the continuous release of lactic acid and fermentation of the lactic acid to hydrogen in and downgradient of the injection area.  Hydrogen from HRC-X is used as an electron donor for reductive dechlorination, which results in dissolution of residual DNAPL and desorption of sorbed contaminants. 

This presentation includes a description of HRC-X, as well as the mechanisms by which chlorinated ethene contaminants are dissolved, desorbed, and degraded.  Laboratory studies showing the effect of biodegradation on DNAPL longevity and case histories describing successful field applications of HRC-X, including total project costs, will also be presented.

Bioremediation of Nitrogenous Toxicants from shrimp farm wastewater using Agricultural Waste Materials

Kishore K. Krishnani, B.P.Gupta, V.Parimala and Mathew Abraham, Central Institute of Brackishwater Aquaculture, 75, Santhome High Road, R.A.Puram, Chennai, 600028, India, Tel: 91-44-24618817, Fax: 91-44-24610311, Email: bioremediationk@yahoo.co.in

Nitrogenous toxicants such as ammonia and nitrite are commonly found in shrimp farm culture water / wastewater. The aim of the present study was to investigate five different agricultural waste materials such as bagasse, coconut husk, rice husk, wheat corns and paddy straw for the removal of these toxicants from shrimp farm wastewater in laboratory condition. The experimental results have shown that toxicants removal are effective with the dose of 1-3 g/ℓ of the materials. Effect of these materials on other water quality parameters such as pH, salinity, alkalinity, dissolved oxygen and phosphates was also studied. The very low cost of these lignocellulosic materials are real advantage that renders it a suitable alternative for the remediation of nitrogenous toxicants from aquaculture water.

Top