ABSTRACT
UV-A (near-UV), UV-C (short-UV) and visible-light assisted Fenton-like treatment of Bisphenol A (BPA) was investigated in pure water and raw freshwater samples spiked with BPA. Treatment performances were evaluated in terms of BPA degradation, dissolved organic carbon (DOC) removal and H2O2 consumption rates. Complete BPA degradation accompanied with significant DOC removal was achieved for all studied processes. Increasing the initial solution pH only exhibited a negative effect on treatment efficiencies when bicarbonate alkalinity was used for pH adjustment, whereas the raw freshwater matrix and irradiation type also influenced oxidation rates appreciably. Acute toxicity analysis employing Vibrio fischeri revealed that the inhibitory effect of BPA decreased significantly during the course of Photo-Fenton-like treatment. Several transformation products could be identified via HPLC and GC-MS analyses including hydroxylated phenolic compounds (hydroquinone; 2-methoxy, 1-4-benzenediol; 4-isopropenylphenol; 4'-hydroxy-acetophenone; 1-(4-cyclohexylphenyl) ethanone; 4-isopropylenecatechol; 4-4'-dihydroxybenzophenone; 4-ethyl,1,3-benzenediol), as well as the ring opening products hexanoic acid methyl ester, fumaric, succinic and oxalic acids. A reaction pathway featuring hydroxylation, dimerization and ring opening steps is proposed.
Subject(s)
Benzhydryl Compounds/chemistry , Benzhydryl Compounds/toxicity , Phenols/chemistry , Phenols/toxicity , Aliivibrio fischeri/drug effects , Chromatography, High Pressure Liquid , Fresh Water/chemistry , Gas Chromatography-Mass Spectrometry , Hydrogen Peroxide/chemistry , Phenols/analysis , Photochemistry/methods , Toxicity Tests/methods , Ultraviolet Rays , WaterABSTRACT
The present work investigates the impacts and mechanisms associated with natural organic matter (NOM) in the Fe0 treatment system of Cu2+ and Zn2+ under roof runoff conditions. The NOM in runoff waters was characterized using XAD-4/8 adsorption resins, copper complexation, acidic capacity and liquid chromatography with online carbon detection. Batch kinetic experiments and flow-through configurations were performed and the results of metal removal were elucidated taking into account the characteristics of NOM. Based on the findings, it is shown that NOM influences the removal of metals through several complex pathways. At an un-favored condition for adsorption of metals, i.e., on iron corrosion products, at pH<Subject(s)
Iron/chemistry
, Metals/chemistry
, Organic Chemicals/chemistry
, Chromatography, Liquid
, Kinetics
, Solubility
