Electrocatalytic Oxidation for Removal of COD from Chlorpyrifos Contaminated Wastewater: Optimization and Performance

Maryam  Dolatabadi; Jafar  Ahmadi; Saeid  Ahmadzadeh

doi:10.18502/jehsd.v10i4.20655

Maryam Dolatabadi Environmental Health Engineering Research Center, Kerman University of Medical Sciences, Kerman, Iran.
Jafar Ahmadi Department of Toxicology and Pharmacology, Kerman University of Medical Sciences, Kerman, Iran.
Saeid Ahmadzadeh Pharmaceutics Research Center, Institute of Pharmaceutical Sciences, Kerman University of Medical Sciences, Kerman, Iran.

DOI: https://doi.org/10.18502/jehsd.v10i4.20655

Keywords: Advanced Oxidation Process; Chemical Oxygen Demand; Chlorpyrifos; Degradation; Removal.

Abstract

Introduction: The removal of chemical oxygen demand (COD) associated with the pesticide chlorpyrifos (CPS) is critical for protecting aquatic ecosystems and public health. Additionally, incomplete degradation of CPS can yield recalcitrant or more toxic transformation products, thereby increasing ecological and human health risks. Therefore, it is essential to removal the COD contributions attributable to CPS from polluted water.

Materials and Methods: In this study, response surface methodology (RSM) was applied as an effective approach to optimize COD removal during anodic oxidation (AO). The effects of the operational parameters, namely CPS concentration, current density, and reaction time, were assessed and subsequently optimized.

Results: The model’s predicted COD removal closely matched experimental observations, exhibiting an R² of 0.9915. ANOVA confirmed the significance of the fitted quadratic model, a high F valuee (324.7), and regression coefficients approaching unity at the 95% confidence level. The lack-of-fit p-value (0.6071) indicates that the lack of fit is not significant. Under optimized conditions, with an CPS concentration of 17.0 mg L⁻¹, current density of 35 mA cm⁻², and a reaction time of 75 min, the maximum COD removal eeficiency reached 70.2%, with an electrical energy consumption of 0.218 kWh m^-3.

Conclusion: ^•OH was the predominant oxidizing species mediating the removal of COD associated with CPS during the AO process. The AO process, recognized for its environmental compatibility, was successfully applied for COD removal. The AO process is an effective treatment for pesticide-contaminated wastewater.