As the use of pesticides in crop production increases, chances for introducing pesticides in the environment dramatically rise. As known, pesticides are harmful substances to different species even in trace amounts, and most of them cause adverse effects such as heart disease and shortness of breath. Carbaryl is a carbamate-based chemical, mainly used as an insecticide. Due to its high toxicity, the United States Environmental Protection Agency has classified carbaryl as a possible human carcinogen. Also, the California Department of Pesticides Regulations has banned its sale in markets since carbaryl could cause different diseases. Moreover, carbaryl is regulated as drinking water contaminants in Korea since people are easily exposed to small amounts of carbaryl through food and drinking water. However, its removal from water is a challenge in drinking water and wastewater treatment facilities, and therefore, there is a need to develop a reliable technology for the treatment of carbaryl.
Advanced Oxidation is a reaction of contaminants and reactive oxygen species such as hydroxyl radical, sulfate radical, and chlorine radical. Advanced oxidation processes (AOPs) mainly employ the reaction to decompose recalcitrant pollutants in water. UV/H₂O₂ has been widely used among AOPs for removing different refractory contaminants in water. However, due to its selectivity of hydroxyl radicals for contaminants, UV/Cl has gained much attention to improve pollutants removal efficiency compared to UV/H₂O₂.
In this study, we tried to investigate whether carbaryl could be effectively decomposed through the UV/Cl process. For carbaryl removal, different operating parameters such as solution pHs, initial concentrations of NaOCl, and UV dosages were investigated to optimize the UV/Cl process. During the degradation of carbaryl, reaction intermediates were determined and also, degradation pathways of carbaryl were investigated.
In this presentation, the results of carbaryl degradation at different experimental conditions will be provided and discussed in detail. Also, the reaction pathways and mechanisms will be suggested and discussed in detail.

Sanghyeon Kim

Appearances