Advanced Treatment of Pesticide-Containing Wastewater Using Fenton Reagent Enhanced by Microwave Electrodeless Ultraviolet.
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.
Shenzhen Academy of Environmental Sciences, Shenzhen 518001, China.
Gong
G
Cheng
Shenzhen Academy of Environmental Sciences, Shenzhen 518001, China.
Jing
J
Lin
Shenzhen Academy of Environmental Sciences, Shenzhen 518001, China.
Jian
J
Lu
Shenzhen Academy of Environmental Sciences, Shenzhen 518001, China.
Xi
X
Zhao
Environmental Engineering Program, Department of Civil Engineering, Auburn University, Auburn, AL 36849, USA.
Zhengqing
Z
Cai
School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Jie
J
Fu
D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008872:Microwaves; D010575:Pesticides / Q000737:chemistry*; D014466:Ultraviolet Rays; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
D006861:Hydrogen Peroxide; D007501:Iron; D010575:Pesticides; D062065:Wastewater; C045076:Fenton's reagent