Ramezanzadeh Shiva, Esmaeilzadeh Feridun, Mowla Dariush, Elhambakhsh Abbas, Kanani Mansour
Department of Chemical and Petroleum Engineering, School of Chemical and Petroleum Engineering, Enhanced Oil and Gas Recovery Institute, Advanced Research Group for Gas Condensate Recovery, Shiraz University, Shiraz, Iran.
Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz, Iran.
Environ Technol. 2023 Nov;44(27):4113-4122. doi: 10.1080/09593330.2022.2080000. Epub 2022 Jun 6.
Dichlorvos or 2,2-dichlorovinyl dimethyl phosphate (DDVP) is a chlorinated organophosphorus pesticide, which is frequently detected in agricultural wastewater. Herein, a batch reactor was used to carry out the supercritical water oxidation (SCWO) of a synthetic wastewater containing dichlorvos as a very hazardous agricultural pollutant. To do so, the impact of four operating parameters including dichlorvos concentration (100-500 ppm), oxidant coefficient (0.7-2), temperature (300-500°C) and time (0-100 s) on dichlorvos removal was optimized by the response surface method (RSM). According to the obtained results, at optimal conditions (i.e. initial concentration of dichlorvos 107.5 ppm, oxidation ratio 1.9234, temperature 419.9°C and time 79.94 s), as an index for dichlorvos removal, the chemical oxygen demand (COD) was found to be about 96.34%. Also, the results of high-performance liquid chromatography test showed that dichloroacetaldehyde (CCLHO) and dichloroacetic acid (CCLHO) were created as intermediate substances during the dichlorvos degradation. Further, the molecular dynamics simulation was performed using ReaxFF force field to show the reaction path and products obtained in each step of the dichlorvos removal. Finally, as an indication, the simulation results indicated a good coordination with the experimental results.
