Influence of Ultraviolet Light Coupled with Hydrogen Peroxide Treatment on Organic Nitrogen and Carbon Precursors and Disinfection By-Product Formation

摘要

This study examined the relationships between organic matter composition and disinfection by-product formationnpotential (DBPFP) following water chlorination. Laboratory synthetic water with various compositions of organicncarbon and nitrogen were treated with ultraviolet light, coupled with hydrogen peroxide (UV=H2O2), to assess theneffects of UV=H2O2 on their DBPFPs. Biologically treated wastewater effluent and histamine dihydrochloride werenspiked in the tested solutions to represent complex organic matter compositions and nitrogenated aromatic structure.nItwas found that carbon-containing precursorswere relatively easier to mineralize byUV=H2O2 treatment thannthe nitrogen-containing compounds. UV=H2O2 processes successfully reduced the precursors of trihalomethanesnand haloacetic acids (HAAs); however, the treatment efficiency was lower for N-nitrosodimethylamine (NDMA)nprecursors. It was also observed that the degree of precursor removal was reduced when raw water was contaminatednby domestic wastewater effluents. In comparison to untreated water, UV=H2O2-treated water produced anhigher ratio of HAAs than trihalomethanes after chlorination. This suggests that a higher fraction of hydrophilicncompounds was obtained after UV=H2O2 treatment. Raw water impaired by wastewater effluent also altered thenformation and species distribution of DBPs, because higher ratio of HAAs and brominated DBPs were observed.