Electrochemical removal of diazinon insecticide in aqueous solution by Pb/β‐PbO₂ anode. Effect of parameters and optimization using response surface methodology

Abstract

Abstract Diazinon is one of the most extensively used organophosphorus pesticides that is used against a variety of agricultural pests and disease vectors and is resistant to biodegradation; its release into the environment is a severe environmental concern due to their widespread use. The aim of this study was to investigate the electrochemical removal of diazinon insecticides from aqueous solutions and to optimize the process by response surface methodology (RSM). This is an experimental study that was performed on a laboratory scale and in a batch mood. scanning electron microscopy, energy dispersive X‐ray, and X‐ray diffraction analyses were performed to accurately evaluate and characterize the coated electrode. The central composite design (CCD) was used to investigate the influence of pH, electrolysis time, diazinon concentration, and current density, as well as the effect of their interaction on the removal of diazinon during the electrochemical process. The results showed that by increasing electrolysis time and current density and decreasing diazinon pH and concentration, diazinon removal efficiency increased. According to the results, Na 2 SO 4 was selected as the supporting electrolyte with the highest degradation efficiency (97.88%) compared to the other two compounds (NaCl and NaNO 3 ). The linear regression coefficient ( R 2 ) between experiments and different response values ​​in the model was .99. The results showed that the amount of AOS in the effluent of the three‐dimensional electrochemical process was increased from 0.06 to 1.22 and the COD/TOC ratio decreased from 2.62 to 1.85, respectively; this indicates the biodegradability of the diazinon insecticide through the electrochemical system. The removal efficiency of COD and TOC in optimum condition was 85.78% and 79.86%, respectively. In general, the electrochemical process using Pb/β‐PbO 2 electrode compared to other methods can be used as a suitable and reliable method for the treatment of effluents containing chemical toxins such as diazinon. Practitioner Points Electrochemical degradation of diazinon insecticide using Pb/β‐PbO 2 anode. Effect of operating parameters on electrodegradation diazinon insecticide in electrochemical processes using Pb/β‐PbO 2 anode. Biodegradability study of diazinon insecticide electrodegradation using Pb/β‐PbO 2 anode. Optimization operating parameters using central composite design (CCD).