Study on the effective removal of chlorpyrifos from water by dielectric barrier discharge (DBD) plasma: The influence of reactive species and different water components

Chlorpyrifos is a widely used organophosphorus pesticide with a significant impact on water. Although non-thermal plasma is a promising technology for removing organic pollutants from water, there is still a limited understanding of how plasma degradation of pesticides works as well as the influence of various water components on pesticide degradation. In this paper, the effects of different influencing factors (different power, different initial concentration of chlorpyrifos, different environmental components) on the degradation of chlorpyrifos in water were investigated, and the relevant mechanism of plasma for the degradation of chlorpyrifos was explored. The experimental results show that the plasma power is 22.2 W and treatment for 10 min, 20 mg/L chlorpyrifos is almost completely degraded and its toxicity is greatly reduced. it was found that Cl− can effectively promote the degradation of chlorpyrifos, while CO32–, HCO3– and HA can inhibit the degradation of chlorpyrifos, SO42− and NO3– have no obvious effect on the removal efficiency of chlorpyrifos. ESR and quenching experiments confirmed that O2–, OH, and 1O2 were effective reactive species in the degradation of chlorpyrifos, and the effect of O2– was more obvious. The long-lived reactive species H2O2, O3 also have a certain promoting effect in the degradation process. The intermediate degradation production and possible degradation path of chlorpyrifos were inferred by UPLC-MS.