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Baczynski T.P.,Cracow University of Technology | Pleissner D.,International Graduate School IHI
Journal of Environmental Science and Health - Part B Pesticides, Food Contaminants, and Agricultural Wastes | Year: 2010

Methanogenic granular sludge and wastewater fermented sludge were used as inocula for batch tests of anaerobic bioremediation of chlorinated pesticide contaminated soil. Results obtained for both types of biomass were similar: 80 to over 90% of γ-hexachlorocyclohexane (γ-HCH), 1,1,1-trichloro-2,2-bis-(4-methoxyphenyl)ethane (methoxychlor) and 1,1,1-trichloro-2,2-bis-(4-chlorophenyl)ethane (DDT) removed in 4-6 weeks. Residual fractions of these pesticides persisted till the end of the 16-week experiment. DDT was degraded through 1,1-dichloro-2,2-bis-(4-chlorophenyl)ethane (DDD). Accumulation of this product corresponded stoichiometrically only to 34-53% of removed DDT, supposedly due to its further transformations, finally resulting in formation of detected 4,4′-dichlorobenzophenone (DBP). Addition of 0.5 mM Tween 80 nonionic surfactant resulted in about a twofold decrease of γ-HCH and methoxychlor residual concentrations, as well as considerably lower DDD accumulation (7-29%) and higher DBP production. However, 1.25 mM dose of this surfactant applied together with granular sludge brought DDD levels back to that observed for treatments with the sludge alone, also impairing DBP formation. © Taylor & Francis Group, LLC.

Baczynski T.P.,Cracow University of Technology | Pleissner D.,International Graduate School IHI | Grotenhuis T.,Wageningen University
Chemosphere | Year: 2010

Anaerobic biodegradation of the pesticides: γ-hexachlorocyclohexane, methoxychlor, o,p′- and p,p′-DDT in field polluted soil was tested at 12, 22 and 30 °C, using methanogenic granular sludge as inoculum. The contaminants were removed quite effectively at all temperatures and their removal rates increased 1.2-1.7 times with the increase in temperature. In most cases pesticide concentrations after an initial substantial decline remained almost constant until the end of experiment. These residual concentrations were also temperature dependent and they were 1.4-8.2 times higher at 12 °C than at 30 °C. DDT was degraded via DDD and accumulation of this metabolite was lower (19-64%) than the corresponding amount of removed DDT, especially at higher temperatures. Further transformation of DDD was confirmed by formation of p,p′-dichlorobenzophenone. Additional experiment demonstrated that removal was limited to readily desorbing fractions of pesticides, while their desorption-resistant fractions persisted in the soil. However, DDD metabolite was only partially removed despite its good desorbability. © 2009 Elsevier Ltd. All rights reserved.

Baczynski T.P.,Cracow University of Technology | Pleissner D.,International Graduate School IHI | Pleissner D.,University of Southern Denmark | Krylow M.,Cracow University of Technology
Clean - Soil, Air, Water | Year: 2012

Bioremediation is intensively studied today as a treatment method for soil contaminated with chlorinated pesticides, chemicals counted among persistent organic pollutants. In the presented work, results of desorption kinetics study using consecutive Tenax TA solid phase extraction (SPE) were tested as predictors of 3-wk anaerobic soil bioremediation effectiveness for chlorinated pesticides γ-HCH, DDT, and methoxychlor. Field-contaminated samples were used in these experiments, and conditions of bioremediation tests were based on previous research. Amounts of pesticides removed during bioremediation (43-98% of initial concentrations) were in most cases much larger (average ratio 1.37) than rapidly desorbing fractions estimated in SPE using two-compartment model of desorption kinetics. The scatter of results was also considerable (standard deviation 0.45). However, there was a statistically significant correlation between amounts removed and rapidly desorbing fractions (R 2=0.64), indicating a relationship between degradability and desorbability. Nonetheless, determination of rapidly desorbing fractions was considered rather a poor indicator of soil bioremediation efficiency for chlorinated pesticides. The total amounts of pesticides desorbed by Tenax in 72h performed better in this respect (R 2=0.73, fraction removed/desorbed=1.10±0.20, average±standard deviation). Disappearance of DDT during bioremediation was accompanied by DDD formation but this was considerably lower than results expected from stoichiometry. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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