title: Photodegradation of Pb-3,4-dihydroxybenzoic acid complex under UV light illumination.
abstract: The degradation of 3,4-dihydroxybenzoic acid (3,4-DHBA) in the presence and absence of Pb(2+) under UV illumination was studied. Addition of Pb(2+) caused the formation of precipitate during photoreaction when the solution pH was higher than 6. The presence of Pb(2+) remarkably inhibited the degradation of 3,4-DHBA and its photodegradation intermediates, while complexation of 3,4-DHBA and its photodegradation intermediates with Pb(2+) decreased the free Pb(2+) in aqueous solutions. Molecular oxygen played an important role in photodegradation of 3,4-DHBA in the presence of Pb(2+). UV-Vis spectroscopy was used to investigate the interaction between Pb(2+) and 3,4-DHBA at different pH conditions, and FT-IR was used to characterize the precipitate formed during photoreaction. The mineralization of 3,4-DHBA was investigate by total organic carbon analysis.
authors.affiliation: Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China. xfhu@yic.ac.cn
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Hu
authors.forename: Wei
authors.initials: W
authors.lastname: Qin
mesh_terms: D002244:Carbon / Q000032:analysis; D006863:Hydrogen-Ion Concentration / Q000528:radiation effects; D062385:Hydroxybenzoates / Q000737:chemistry* / Q000528:radiation effects*; D007854:Lead / Q000737:chemistry* / Q000528:radiation effects*; D009566:Nitrates / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D010782:Photolysis / Q000528:radiation effects*; D012995:Solubility / Q000528:radiation effects; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D014466:Ultraviolet Rays
chemical_list: D062385:Hydroxybenzoates; D009566:Nitrates; D012996:Solutions; D007854:Lead; C009091:protocatechuic acid; D002244:Carbon; C031618:sodium nitrate; D010100:Oxygen