Reinvestigation on the ozonation of N-nitrosodimethylamine: Influencing factors and degradation mechanism.

摘要: N-nitrosodimethylamine (NDMA), as a new disinfection byproduct, is potential carcinogen. In this study, we focused on the role of ozone in NDMA degradation. We characterized removal efficiency, influencing factors and degradation mechanism. Our results demonstrated that ozonation was an efficient process for The efficiency affected by initial concentration; higher dosing required utilization. oxidation favored at high dosage pH. under various pH well hydroxyl radical (OH) inhibition experiments verified OH generated from dominated oxidation. main products were methylamine (MA), dimethylamine (DMA), nitromethane (NM) ammonium (AM). Their yields changed with amount provided. A mechanism proposed. It suggested induced attacking through any four pathways, oxygen involving process. MA generation due to amine nitrogen methyl group. DMA formation related nitrosyl via parallel pathway. speculate supersaturated dissolved decomposition responsible NM further DMA. AM may be exposure.