title: Photodegradation of organic matter in fresh garbage leachate using immobilized nano-sized TiO2 as catalysts.
abstract: Two immobilized nano-sized TiO2 catalysts, TiO2/activated carbon (TiO2/AC) and TiO2/silica gel (SG) (TiO2/SG), were prepared by the sol-gel method, and their use in the photocatalytic degradation of organic matter in fresh garbage leachate under UV irradiation was investigated. The influences of the catalyst dosage, the initial solution pH, H2O2 addition and the reuse of the catalysts were evaluated. The degradation of organic matter was assessed based on the decrease of the chemical oxygen demand (COD) in the leachate. The results indicated that the degradation of the COD obeyed first-order kinetics in the presence of both photocatalysts. The degradation rate of COD was found to increase with increasing catalyst dosage up to 9 g/L for TiO2/AC and 6 g/L for TiO2/SG, above which the degradation began to attenuate. Furthermore, the degradation rate first increased and then decreased as the solution pH increased from 2 to 14, and the degradation rate increased as the amount of H2O2 increased to 2.93 mM, after which it remained constant. No obvious decrease in the rate of COD degradation was observed during the first four repeated uses of the photocatalysts, indicating that the catalysts could be recovered and reused. Compared with TiO2/AC, TiO2/SG exhibited higher efficiency in photocatalyzing the degradation of COD in garbage leachate.
authors.affiliation: College of Resources and Environment, Southwest University, The Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Chongqing 400715, China E-mail: zxl@swu.edu.cn and The Key Laboratory of Agricultural Resources and Environment of Chongqing, Chongqing 400716, China.
authors.forename: C
authors.initials: C
authors.lastname: Chen
authors.affiliation: College of Resources and Environment, Southwest University, The Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Chongqing 400715, China E-mail: zxl@swu.edu.cn and The Key Laboratory of Agricultural Resources and Environment of Chongqing, Chongqing 400716, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Xie
authors.affiliation: College of Resources and Environment, Southwest University, The Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Chongqing 400715, China E-mail: zxl@swu.edu.cn and The Key Laboratory of Agricultural Resources and Environment of Chongqing, Chongqing 400716, China.
authors.forename: B Q
authors.initials: BQ
authors.lastname: Hu
authors.affiliation: College of Resources and Environment, Southwest University, The Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, Chongqing 400715, China E-mail: zxl@swu.edu.cn and The Key Laboratory of Agricultural Resources and Environment of Chongqing, Chongqing 400716, China.
authors.forename: X L
authors.initials: XL
authors.lastname: Zhao
mesh_terms: D057919:Biological Oxygen Demand Analysis; D002384:Catalysis; D002606:Charcoal / Q000737:chemistry; D005735:Garbage; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry* / Q000528:radiation effects; D010782:Photolysis; D058428:Silica Gel / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*
chemical_list: D009930:Organic Chemicals; C009495:titanium dioxide; D002606:Charcoal; D058428:Silica Gel; D006861:Hydrogen Peroxide; D014025:Titanium