Promoted Dissipation and Detoxification of Atrazine by Graphene Oxide Coexisting in Water

Abstract

Abstract Herbicide atrazine (ATZ) has a detrimental effect on health of aquatic ecosystems, and has become a global concern in recent years. but understanding of its persistence and potential toxicity under combined pollution, especially in the coexistence of other emerging pollutants, remains limited. In this work, the dissipation and transformation of ATZ in combination with graphene oxide (GO) in water were investigated. Results showed that dissipation rates of ATZ dramatically increased by 15%-95% with half-lives shortened by 15%-40% depending on initial concentrations of ATZ, the products were mainly toxic chloro-dealkylated intermediates (deethylatrazine (DEA) and deisopropylatrazine (DIA)), but their contents were significantly lower under coexistence of GO compared to ATZ alone. In the presence of GO, the nontoxic dechlorinated metabolite hydroxyatrazine (HYA) was detected earlier than 2-9 days, and ATZ transformation into HYA was increased by 6%-18% during 21-day incubation periods. This study indicated that the coexistence of GO enhanced the dissipation and detoxification of ATZ. From a remediation standpoint, GO-induced hydrolytic dechlorination of ATZ can reduce its ecological toxicity. But the environmental risks of ATZ for aquatic ecosystem under the coexistence of GO should still be given necessary prominence due to potential hazard of ATZ adsorbed on GO and predominant degradation products (DEA and DIA).