title: Heterogeneous photo-catalysis system for the degradation of azo dye Reactive Black 5 (RB5).
abstract: This study investigated a heterogeneous photo-catalysis system by introducing a novel brick supported iron oxide (denoted as B1) for the heterogeneous photoassisted degradation of Reactive Black 5 (RB5) at pH value from 3 to 7 in a three-phase (gas-liquid-solid) fluidized bed reactor (3P-FBR). Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD) and N(2) adsorption/desorption were used to characterize the B1 catalyst. The in situ formation of hydrogen peroxide and the depletion of oxalic acid by photochemical cycle of Fe(III)-oxalate complex under UVA light (λ = 365 nm) were studied. The effects of the solution pH and the concentration of oxalic acid on the degradation of RB5 are elucidated. About 90% decolourization was measured and 80% of the total organic carbon (TOC) was eliminated at pH 5.0 after 120 min for 20 mg/L RB5 in presence of 10 g/L B1 catalyst, 30 mg/L oxalic acid under 15 W UVA light. A mechanism for the photocatalytic degradation of RB5 over B1 catalyst is proposed.
authors.affiliation: Department of Chemical Engineering, National Cheng Kung University, Tainan City, Taiwan. yhhuang@mail.ncku.edu.tw
authors.forename: Yao-Hui
authors.initials: YH
authors.lastname: Huang
authors.forename: Hau-Cheng
authors.initials: HC
authors.lastname: Wei
authors.forename: Hung-Ta
authors.initials: HT
authors.lastname: Chen
mesh_terms: D002384:Catalysis; D004396:Coloring Agents / Q000737:chemistry* / Q000528:radiation effects; D005290:Ferric Compounds / Q000737:chemistry*; D009282:Naphthalenesulfonates / Q000737:chemistry* / Q000528:radiation effects; D019815:Oxalic Acid / Q000737:chemistry*; D010782:Photolysis; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000528:radiation effects; D018508:Water Purification / Q000379:methods
chemical_list: D004396:Coloring Agents; D005290:Ferric Compounds; D009282:Naphthalenesulfonates; D014874:Water Pollutants, Chemical; C000499:ferric oxide; D019815:Oxalic Acid; C063421:Remazol black B