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Advanced Treatment of Pesticide-Containing Wastewater Using Fenton Reagent Enhanced by Microwave Electrodeless Ultraviolet.

Cheng G, Lin J, Lu J, Zhao X, Cai Z, Fu J - Biomed Res Int (2015)

Bottom Line: Under the optimal conditions, the reaction exhibited high mineralization degrees of organics, where COD and dissolved organic carbon (DOC) concentration decreased from 183.2 mg/L to 36.9 mg/L and 43.5 mg/L to 27.8 mg/L, respectively.Three main pesticides in the wastewater, as Dimethoate, Triazophos, and Malathion, were completely removed by the MWEUV/Fenton process within 120 min.The high degree of pesticides decomposition and mineralization was proved by the detected inorganic anions.

View Article: PubMed Central - PubMed

Affiliation: Shenzhen Academy of Environmental Sciences, Shenzhen 518001, China.

ABSTRACT
The photo-Fenton reaction is a promising method to treat organic contaminants in water. In this paper, a Fenton reagent enhanced by microwave electrodeless ultraviolet (MWEUV/Fenton) method was proposed for advanced treatment of nonbiodegradable organic substance in pesticide-containing biotreated wastewater. MWEUV lamp was found to be more effective for chemical oxygen demand (COD) removal than commercial mercury lamps in the Fenton process. The pseudo-first order kinetic model can well describe COD removal from pesticide-containing wastewater by MWEUV/Fenton, and the apparent rate constant (k) was 0.0125 min(-1). The optimal conditions for MWEUV/Fenton process were determined as initial pH of 5, Fe(2+) dosage of 0.8 mmol/L, and H2O2 dosage of 100 mmol/L. Under the optimal conditions, the reaction exhibited high mineralization degrees of organics, where COD and dissolved organic carbon (DOC) concentration decreased from 183.2 mg/L to 36.9 mg/L and 43.5 mg/L to 27.8 mg/L, respectively. Three main pesticides in the wastewater, as Dimethoate, Triazophos, and Malathion, were completely removed by the MWEUV/Fenton process within 120 min. The high degree of pesticides decomposition and mineralization was proved by the detected inorganic anions.

No MeSH data available.


Evolution of inorganic anions in MWEUV/Fenton. Experimental parameters: initial pH value of 5, H2O2 dosage of 100 mmol/L, and Fe2+ dosage of 0.8 mmol/L.
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Related In: Results  -  Collection


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fig8: Evolution of inorganic anions in MWEUV/Fenton. Experimental parameters: initial pH value of 5, H2O2 dosage of 100 mmol/L, and Fe2+ dosage of 0.8 mmol/L.

Mentions: The concentration profiles of Dimethoate, Triazophos, and Malathion during the MWEUV/Fenton process are shown in Figure 7. They displayed similar profiles, a rapid increase in pesticides concentration at the initial stage of MWEUV/Fenton process, and Dimethoate and Malathion were completely removed within 240 min. Figure 8 exhibits the concentration changes of inorganic anions (NO3−, SO42−, and PO43−) in the reaction. The increases of SO42− and PO43− concentration in wastewater were mainly attributed to the breakage of chemical bonds such as S=P, P-O, and S-P. The results also suggested a deep decomposition and mineralization of pesticide molecules occurring under the attack of hydroxyl radicals.


Advanced Treatment of Pesticide-Containing Wastewater Using Fenton Reagent Enhanced by Microwave Electrodeless Ultraviolet.

Cheng G, Lin J, Lu J, Zhao X, Cai Z, Fu J - Biomed Res Int (2015)

Evolution of inorganic anions in MWEUV/Fenton. Experimental parameters: initial pH value of 5, H2O2 dosage of 100 mmol/L, and Fe2+ dosage of 0.8 mmol/L.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4548131&req=5

fig8: Evolution of inorganic anions in MWEUV/Fenton. Experimental parameters: initial pH value of 5, H2O2 dosage of 100 mmol/L, and Fe2+ dosage of 0.8 mmol/L.
Mentions: The concentration profiles of Dimethoate, Triazophos, and Malathion during the MWEUV/Fenton process are shown in Figure 7. They displayed similar profiles, a rapid increase in pesticides concentration at the initial stage of MWEUV/Fenton process, and Dimethoate and Malathion were completely removed within 240 min. Figure 8 exhibits the concentration changes of inorganic anions (NO3−, SO42−, and PO43−) in the reaction. The increases of SO42− and PO43− concentration in wastewater were mainly attributed to the breakage of chemical bonds such as S=P, P-O, and S-P. The results also suggested a deep decomposition and mineralization of pesticide molecules occurring under the attack of hydroxyl radicals.

Bottom Line: Under the optimal conditions, the reaction exhibited high mineralization degrees of organics, where COD and dissolved organic carbon (DOC) concentration decreased from 183.2 mg/L to 36.9 mg/L and 43.5 mg/L to 27.8 mg/L, respectively.Three main pesticides in the wastewater, as Dimethoate, Triazophos, and Malathion, were completely removed by the MWEUV/Fenton process within 120 min.The high degree of pesticides decomposition and mineralization was proved by the detected inorganic anions.

View Article: PubMed Central - PubMed

Affiliation: Shenzhen Academy of Environmental Sciences, Shenzhen 518001, China.

ABSTRACT
The photo-Fenton reaction is a promising method to treat organic contaminants in water. In this paper, a Fenton reagent enhanced by microwave electrodeless ultraviolet (MWEUV/Fenton) method was proposed for advanced treatment of nonbiodegradable organic substance in pesticide-containing biotreated wastewater. MWEUV lamp was found to be more effective for chemical oxygen demand (COD) removal than commercial mercury lamps in the Fenton process. The pseudo-first order kinetic model can well describe COD removal from pesticide-containing wastewater by MWEUV/Fenton, and the apparent rate constant (k) was 0.0125 min(-1). The optimal conditions for MWEUV/Fenton process were determined as initial pH of 5, Fe(2+) dosage of 0.8 mmol/L, and H2O2 dosage of 100 mmol/L. Under the optimal conditions, the reaction exhibited high mineralization degrees of organics, where COD and dissolved organic carbon (DOC) concentration decreased from 183.2 mg/L to 36.9 mg/L and 43.5 mg/L to 27.8 mg/L, respectively. Three main pesticides in the wastewater, as Dimethoate, Triazophos, and Malathion, were completely removed by the MWEUV/Fenton process within 120 min. The high degree of pesticides decomposition and mineralization was proved by the detected inorganic anions.

No MeSH data available.