The photodegradation of bisphenol A （BPA） in aqueous solution containing metal ions and ascorbic acid （AsA） was investigated. After strong irradiation, the aqueous solution containing AsA and Cu^2＋ could produce hydroxyl radicals that induced the photodegradation of BPA. The photodegradation efficiency of BPA in the solution containing 70 μmol·L^1 Cu^2＋ and 15 mg·L^1 AsA reached 59% at pH 6.0 after 4 hours irradiation with high pressure mercury lamp. The photodegradation efficiency of BPA reached 10% after 4 hours irradiation with daylight lamp in the presence of 70 μmol·L^1 Cu^2＋ and 15 mg·L^1 ascorbic acid. BPA was not degraded in the aqueous solution only containing AsA or Cu^2＋. The BPA photodegradation in aqueous solution containing AsA and Fe^3＋ was weaker than in aqueous solution that containing AsA and Cu^2＋ at the same concentration. This work showed a new route of the BPA photodegradation in aqueous environment.
PENG Zhang＇e ZHANG Xu YANG Liu WU Feng DENG Nansheng
Effects of algae Nitzschia hantzschiana, Fe（Ⅲ） ions, humic acid, and pH on the photochemical reduction of Hg（Ⅱ） using the irradiation of metal halide lamps （λ〉 365 nm, 250 W） were investigated. The photoreduction rate of Hg（Ⅱ） was found to increase with increasing concentrations of algae, Fe（Ⅲ） ions, and humic acid. Alteration of pH value affected the photoreduction of Hg（Ⅱ） in aqueous solution with or without algae. The photoreduction rate of Hg（Ⅱ） decreased with increasing initial Hg（Ⅱ） concentration in aqueous solution in the presence of algae. The photochemical kinetics of initial Hg（Ⅱ） and algae concentrations on the photoreduction of Hg（Ⅱ） were studied at pH 7.0. The study on the total Hg mass balance in terms of photochemical process revealed that more than 42% of Hg（Ⅱ） from the algal suspension was reduced to volatile metallic Hg under the conditions investigated.
