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Treatment of pesticide wastewater by moving-bed biofilm reactor combined with Fenton-coagulation pretreatment.
J Hazard Mater. 2007 Jun 01; 144(1-2):577-84.JH

Abstract

In order to treat pesticide wastewater having high chemical oxygen demand (COD) value and poor biodegradability, Fenton-coagulation process was first used to reduce COD and improve biodegradability and then was followed by biological treatment. Optimal experimental conditions for the Fenton process were determined to be Fe(2+) concentration of 40 mmol/L and H(2)O(2) dose of 97 mmol/L at initial pH 3. The interaction mechanism of organophosphorous pesticide and hydroxyl radicals was suggested to be the breakage of the P=S double bond and formation of sulfate ions and various organic intermediates, followed by formation of phosphate and consequent oxidation of intermediates. For the subsequent biological treatment, 3.2g/L Ca(OH)(2) was added to adjust the pH and further coagulate the pollutants. The COD value could be evidently decreased from 33,700 to 9300 mg/L and the ratio of biological oxygen demand (BOD(5)) to COD of the wastewater was enhanced to over 0.47 by Fenton oxidation and coagulation. The pre-treated wastewater was then subjected to biological oxidation by using moving-bed biofilm reactor (MBBR) inside which tube chip type bio-carriers were fluidized upon air bubbling. Higher than 85% of COD removal efficiency could be achieved when the bio-carrier volume fraction was kept more than 20% by feeding the pretreated wastewater containing 3000 mg/L of inlet COD at one day of hydraulic retention time (HRT), but a noticeable decrease in the COD removal efficiency when the carrier volume was decreased down to 10%, only 72% was observed. With the improvement of biodegradability by using Fenton pretreatment, also due to the high concentration of biomass and high biofilm activity using the fluidizing bio-carriers, high removal efficiency and stable operation could be achieved in the biological process even at a high COD loading of 37.5 gCOD/(m(2)carrierday).

Authors+Show Affiliations

School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin 150090, PR China. hitchensheng@126.comNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

17141410

Citation

Chen, Sheng, et al. "Treatment of Pesticide Wastewater By Moving-bed Biofilm Reactor Combined With Fenton-coagulation Pretreatment." Journal of Hazardous Materials, vol. 144, no. 1-2, 2007, pp. 577-84.
Chen S, Sun D, Chung JS. Treatment of pesticide wastewater by moving-bed biofilm reactor combined with Fenton-coagulation pretreatment. J Hazard Mater. 2007;144(1-2):577-84.
Chen, S., Sun, D., & Chung, J. S. (2007). Treatment of pesticide wastewater by moving-bed biofilm reactor combined with Fenton-coagulation pretreatment. Journal of Hazardous Materials, 144(1-2), 577-84.
Chen S, Sun D, Chung JS. Treatment of Pesticide Wastewater By Moving-bed Biofilm Reactor Combined With Fenton-coagulation Pretreatment. J Hazard Mater. 2007 Jun 1;144(1-2):577-84. PubMed PMID: 17141410.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Treatment of pesticide wastewater by moving-bed biofilm reactor combined with Fenton-coagulation pretreatment. AU - Chen,Sheng, AU - Sun,Dezhi, AU - Chung,Jong-Shik, Y1 - 2006/10/28/ PY - 2005/11/29/received PY - 2006/09/06/revised PY - 2006/10/25/accepted PY - 2006/12/5/pubmed PY - 2007/8/31/medline PY - 2006/12/5/entrez SP - 577 EP - 84 JF - Journal of hazardous materials JO - J Hazard Mater VL - 144 IS - 1-2 N2 - In order to treat pesticide wastewater having high chemical oxygen demand (COD) value and poor biodegradability, Fenton-coagulation process was first used to reduce COD and improve biodegradability and then was followed by biological treatment. Optimal experimental conditions for the Fenton process were determined to be Fe(2+) concentration of 40 mmol/L and H(2)O(2) dose of 97 mmol/L at initial pH 3. The interaction mechanism of organophosphorous pesticide and hydroxyl radicals was suggested to be the breakage of the P=S double bond and formation of sulfate ions and various organic intermediates, followed by formation of phosphate and consequent oxidation of intermediates. For the subsequent biological treatment, 3.2g/L Ca(OH)(2) was added to adjust the pH and further coagulate the pollutants. The COD value could be evidently decreased from 33,700 to 9300 mg/L and the ratio of biological oxygen demand (BOD(5)) to COD of the wastewater was enhanced to over 0.47 by Fenton oxidation and coagulation. The pre-treated wastewater was then subjected to biological oxidation by using moving-bed biofilm reactor (MBBR) inside which tube chip type bio-carriers were fluidized upon air bubbling. Higher than 85% of COD removal efficiency could be achieved when the bio-carrier volume fraction was kept more than 20% by feeding the pretreated wastewater containing 3000 mg/L of inlet COD at one day of hydraulic retention time (HRT), but a noticeable decrease in the COD removal efficiency when the carrier volume was decreased down to 10%, only 72% was observed. With the improvement of biodegradability by using Fenton pretreatment, also due to the high concentration of biomass and high biofilm activity using the fluidizing bio-carriers, high removal efficiency and stable operation could be achieved in the biological process even at a high COD loading of 37.5 gCOD/(m(2)carrierday). SN - 0304-3894 UR - https://www.unboundmedicine.com/medline/citation/17141410/Treatment_of_pesticide_wastewater_by_moving_bed_biofilm_reactor_combined_with_Fenton_coagulation_pretreatment_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0304-3894(06)01299-4 DB - PRIME DP - Unbound Medicine ER -