title: Degradation of organic dyes via bismuth silver oxide initiated direct oxidation coupled with sodium bismuthate based visible light photocatalysis.
abstract: Organic dye degradation was achieved via direct oxidation by bismuth silver oxide coupled with visible light photocatalysis by sodium bismuthate. Crystal violet dye decomposition by each reagent proceeded via two distinct pathways, each involving different active oxygen species. A comparison of each treatment method alone and in combination demonstrated that using the combined methods in sequence achieved a higher degree of degradation, and especially mineralization, than that obtained using either method alone. In the combined process direct oxidation acts as a pretreatment to rapidly bleach the dye solution which substantially facilitates subsequent visible light photocatalytic processes. The integrated sequential direct oxidation and visible light photocatalysis are complementary manifesting a > 100% increase in TOC removal, compared to either isolated method. The combined process is proposed as a novel and effective technology based on one primary material, sodium bismuthate, for treating wastewaters contaminated by high concentrations of organic dyes.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, PR China.
authors.forename: Kai
authors.initials: K
authors.lastname: Yu
authors.forename: Shaogui
authors.initials: S
authors.lastname: Yang
authors.forename: Cun
authors.initials: C
authors.lastname: Liu
authors.forename: Hongzhe
authors.initials: H
authors.lastname: Chen
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Cheng
authors.initials: C
authors.lastname: Sun
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Boyd
mesh_terms: D001729:Bismuth / Q000737:chemistry*; D002384:Catalysis; D004396:Coloring Agents / Q000737:chemistry / Q000302:isolation & purification*; D008401:Gas Chromatography-Mass Spectrometry; D008027:Light; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D010782:Photolysis; D018030:Silver Compounds / Q000737:chemistry*; D053719:Tandem Mass Spectrometry; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D004396:Coloring Agents; D010087:Oxides; D018030:Silver Compounds; D014874:Water Pollutants, Chemical; C040225:disilver oxide; D001729:Bismuth