Pesticide production wastewater treatment by Electro-Fenton using Taguchi experimental design

In this study, the electro - Fenton (EF) method was applied to remove total organic carbon (TOC) from the pesticide production wastewater containing tricyclazole (TC). Statistical Taguchi method was used to optimize the treatment performance. Analysis of variance (ANOVA) indicated that the polynomial regression model fitted experimental data with R-2 of 0.969. The optimal conditions for eliminating 75.4% TOC and 93.7% TC, were 0.2 mM of Fe2+, 990 mg/L of Na2SO4, 180 min of reaction time at pH 3 with 2.22 mA/cm(2) of current density. The removal of TC present in the wastewater followed the first-order reaction kinetic model (R-2 = 0.993); while that was the second-order kinetic model in the case of the TOC removal (R-2 = 0.903). In addition, the experimental results and theory approaches (density functional theory and natural bond orbital calculations) also showed that the C-N bond breaking and nitrate ions cleavage ammonia. Acute toxicity of the pesticide wastewater after treatment (PWAT) on microcrustacean showed that the treated wastewater still exhibited high toxicity against D. magna, with LC50 values of 3.84%, 2.68%, 2.05%, and 1.78% at 24 h, 48 h, 72 h, and 96 h, respectively.