Removal of triazophos pesticide from wastewater with Fenton reagent

Abstract

The catalytic oxidation of triazophos pesticide from wastewater using Fenton reagent was investigated at bench-scale in this study. Synthesized wastewater and actual industrial triazophos pesticide wastewater taken from a pesticide company were examined sequentially. The COD values of the synthesized and actual industrial triazophos pesticide wastewater samples were 3242 and 3418 mg/L, respectively, and the triazophos concentration in these wastewater samples was 0.06% by weight. The effects of reaction conditions including the dosages of FeSO 4·7H 2O and H 2O 2, the pH value of the environment, and the stirring time on COD removal from the synthesized wastewater were evaluated, and COD removal efficiency of 96.3% with a corresponding effluent COD value of 120 mg/L was achieved under optimal reaction conditions of a pH value of 4, a dosage of 2.5 g/L of FeSO 4·7H 2O and 100 mL/L of 30% H 2O 2 solution, and a stirring time of 90 min. Results also showed that 71.2% of nitrogen and 68.5% of phosphorous in the synthesized triazophos wastewater were converted to NO 3 − and PO 4 3−, respectively, at the optimal reaction condition. When the actual industrial wastewater was treated at a pH value of 4, COD removal efficiency of 85.4% with a corresponding effluent COD value of 499 mg/L were reached at optimal condition of a dosage of 5.0 g/L of FeSO 4·7H 2O and 75 mL/L of 30% H 2O 2 solution, and a stirring time of 90 min. The results of this study can be referred for the design of a treatment process for the actual industrial triazophos wastewater.