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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: MWEUV lamp was found to be more effective for chemical oxygen demand (COD) removal than commercial mercury lamps in the Fenton process.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.


Related in: MedlinePlus

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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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
Related In: Results  -  Collection

License
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: MWEUV lamp was found to be more effective for chemical oxygen demand (COD) removal than commercial mercury lamps in the Fenton process.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.


Related in: MedlinePlus