title: Photocatalytic oxidation of humic acid and its effect on haloacetic acid formation potential: a fluorescence spectrometry study.
abstract: By fluorescence spectrometry method, molecular conformation changes of humic acid (HA) during the photocatalytic oxidation process were studied. Haloacetic acids formation potential (HAAFP) changes during the oxidation process were also measured. The results indicated that aromatic rings of HA decreased and conjugated double bonds were destroyed at the beginning of the process. Meanwhile, organic matter with large molecular weight decomposed into intermediates with smaller molecular weight, such as tryptophan and tyrosine. HA can be degraded almost completely, but not be mineralized thoroughly. Structures of the intermediates were changing during the oxidation process. Molecular structure transformation of HA led to the fluctuation tendency of the HAAFP changes during the photocatalytic oxidation process. HAAFP increased to 1.22 times that in raw water after 30 min of ultraviolet (UV) radiation, and decreased to 0.66 times that in raw water after 60 min of photocatalytic oxidation.
authors.affiliation: College of Hydrology and Water Resources, Hohai University, Nanjing, China. wshyxj@126.com
authors.forename: Yan
authors.initials: Y
authors.lastname: Xiaoju
authors.forename: Bao
authors.initials: B
authors.lastname: Ruiling
authors.forename: Yu
authors.initials: Y
authors.lastname: Shuili
authors.forename: Li
authors.initials: L
authors.lastname: Qiongfang
authors.forename: Chen
authors.initials: C
authors.lastname: Wei
mesh_terms: D000085:Acetates / Q000737:chemistry*; D000327:Adsorption; D002384:Catalysis; D006812:Humic Substances / Q000032:analysis*; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D013050:Spectrometry, Fluorescence / Q000379:methods*; D018508:Water Purification
chemical_list: D000085:Acetates; D006812:Humic Substances