title: Photodegradation mechanism of sulfadiazine catalyzed by Fe(III), oxalate and algae under UV irradiation.
abstract: Photodegradation mechanism of sulfadiazine (SD) in a solution containing Fe(III), oxalate and algae were investigated in this study. The results indicated that the degradation of SD was slow in a solution containing Fe(III) or oxalate, whereas it was markedly enhanced when Fe(III) and oxalate coexisted. The optimal pH for formation of *OH was 4; a higher or lower pH resulted in a decrease in formation of OH. A moderate increase of oxalate concentration was beneficial to the formation of *OH and the degradation of SD, and the algae enhanced the degradation rate of SD in a solution containing Fe(III) and oxalate. Also, the degradation rate of SD rapidly decreased at low initial concentrations but slowly decreased at high initial concentrations, and pseudo-first order kinetics described the degradation process of SD well. A possible reaction mechanism in solution containing Fe(III), oxalate and algae was proposed, and attack by *OH was the main pathway of SD degradation in the photocatalytic reaction.
authors.affiliation: The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, China. zjwseu@126.com
authors.forename: Junwei
authors.initials: J
authors.lastname: Zhang
authors.forename: Li
authors.initials: L
authors.lastname: Ma
mesh_terms: D001673:Biodegradation, Environmental / Q000528:radiation effects; D048408:Chlorella vulgaris / Q000737:chemistry / Q000378:metabolism; D005290:Ferric Compounds / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry; D010070:Oxalates / Q000737:chemistry; D010782:Photolysis; D013411:Sulfadiazine / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D014466:Ultraviolet Rays; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D018508:Water Purification / Q000379:methods*
chemical_list: D005290:Ferric Compounds; D017665:Hydroxyl Radical; D010070:Oxalates; D013411:Sulfadiazine; D062065:Wastewater; D014874:Water Pollutants, Chemical