Mechanism, kinetics and DBPs formation of UV/NH2Cl process on sulfathiazole removal in aqueous solution

In this paper, UV/NH 2 Cl process was used to research the degradation of sulfathiazole (STZ) and the formation of disinfection by-products (DBPs) after disinfection were detected. UV and NH 2 Cl process showed a synergistic effect on the removal of STZ. Natural organic matter and CO 3 2− inhibited the STZ degradation, NO 3 − promoted the degradation of STZ, whereas NH 2 Cl concentration, HCO 3 − and Cl − had dual effects on the removal of STZ. The removal of STZ by UV/NH 2 Cl was slightly influenced by pH. The contribution of reactive chlorine species and reactive nitrogen species to STZ degradation was significantly higher than that of HO · . Possible STZ degradation pathways were presented by analyzing intermediate products. In addition, the pretreatment of UV/NH 2 Cl significantly reduced the formation of DBPs during NH 2 Cl or NaClO disinfection. In conclusion, UV/NH 2 Cl process is an effective water treatment technology and can be well applied for practical purposes.