Pesticide Industry Wastewater Treatment with Photo-Fenton Process

Abstract

Pesticides are agricultural drugs used to combat weeds, plants, and insects that are harmful to the product and affect the efficiency during the cultivation of plants. However, pesticides are highly toxic, carcinogenic, and mutagenic, even at low concentrations and pesticides persist in nature for a long period. Pesticide manufacturing industry wastewater causes pollution problems due to the toxic components, high chemical oxygen demand (COD), biochemical oxygen demand (BOD), high total dissolved solids (TDS) and intensive color, disgusting odor, and generally low pH values. Since adequate treatment efficiency cannot be obtained with biological treatment in these wastewaters, chemical processes based on advanced oxidation methods are needed for the removal of toxicity and organic load caused by pesticide wastewater. Advanced oxidation methods are based on the formation of hydroxyl radicals (OH●) and provide the conversion of toxic organic substances into harmless products. The major objective of this study was to investigate the oxidation of raw pesticide wastewater using the photo-Fenton process by using a Box-Behnken statistical experimental design and surface response methodology. In the photo-Fenton experiments, the effects of different oxidant and catalyst concentrations for COD removal at different reaction times were investigated using Box-Behnken statistical design. Because of the studies, the most appropriate reaction conditions according to COD removal are: H2O2 concentration of 1000 mg/L, Fe+2 concentration of 325 mg/L, reaction time of 35 min, and COD yield of 70%.