Unexpected Role of Nitrite in Promoting Transformation of Sulfonamide Antibiotics by Peracetic Acid: Reactive Nitrogen Species Contribution and Harmful Disinfection Byproduct Formation Potential

• DOI: 10.1021/acs.est.1c06026
• Publication Date: 2021-12-29T19:13:56Z
• Authors: Tongcai Liu; Jiabin Chen; Nan Li; Shaoze Xiao; Ching-Hua Huang; Longlong Zhang; Yao Xu; Yalei Zhang; Xuefei Zhou
• Keywords: Disinfection; Sulfonamides; Peracetic Acid; Reactive Nitrogen Species; 01 natural sciences; Nitrites; 6. Clean water; Anti-Bacterial Agents; Water Purification; 0105 earth and related environmental sciences

Peracetic acid (PAA) is an emerging oxidant and disinfectant for wastewater (WW) treatment due to limited harmful disinfection byproduct (DBP) formation. Nitrite (NO2-) is a ubiquitous anion in water, but the impact of NO2- on PAA oxidation and disinfection has been largely overlooked. This work found for the first time that NO2- could significantly promote the oxidation of sulfonamide antibiotics (SAs) by PAA. Unexpectedly, the reactive nitrogen species (RNS), for example, peroxynitrite (ONOO-), rather than conventional organic radicals (R-O•) or reactive oxygen species (ROS), played major roles in SAs degradation. A kinetic model based on first-principles was developed to elucidate the reaction mechanism and simulate reaction kinetics of the PAA/NO2- process. Structural activity assessment and quantum chemical calculations showed that RNS tended to react with an aromatic amine group, resulting in more conversion of NO2--N to organic-N. The formation of nitrated and nitrosated byproducts and the enhancement of trichloronitromethane formation potential might be a prevalent problem in the PAA/NO2- process. This study provides new insights into the reaction of PAA with NO2- and sheds light on the potential risks of PAA in WW treatment in the presence of NO2-.