title: Reuse of sewage sludge as a catalyst in ozonation--efficiency for the removal of oxalic acid and the control of bromate formation.
abstract: Sewage derived sludge is produced with an annual amount increase of 2% all over the world and it is an urgent issue to be addressed by human being. In the present study, sludge was converted into sludge-based catalyst (SBC) with ZnCl2 as activation agent and characterized by several methods (e.g., scanning electron microscope, X-ray photoelectron spectroscope and Fourier transform infrared spectroscope). Then it was used as a catalyst to enhance the removal of refractory organic matter, oxalic acid, and to control the formation of bromate (BrO3-) in bench semi-continuous ozonation experiments. The effects of various operating parameters on the control of BrO3- formation were investigated. Furthermore, the mechanism for the enhancement of organic matter removal and the control of BrO3- formation was discussed as well. Results indicate that the combination of SBC with ozone shows a strong synergistic effect, resulting in a notable improvement on oxalic acid removal. A crucial surface reaction mechanism for the enhancement of organic matter removal is proposed on the basis of negative effect of higher pH and no inhibition effect of tert-butanol. The control for BrO3- formation was demonstrated and the reason for its control in the process of O3/SBC is the combined effect of SBC reductive properties, ozone exposure decrease and hydrogen peroxide concentration increase.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China.
authors.forename: Gang
authors.initials: G
authors.lastname: Wen
authors.forename: Zhi-Hui
authors.initials: ZH
authors.lastname: Pan
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
authors.forename: Zheng-Qian
authors.initials: ZQ
authors.lastname: Liu
authors.forename: Lei
authors.initials: L
authors.lastname: Zhao
authors.forename: Jun-Jing
authors.initials: JJ
authors.lastname: Li
mesh_terms: D001959:Bromates / Q000737:chemistry; D002384:Catalysis; D002712:Chlorides / Q000737:chemistry; D019815:Oxalic Acid / Q000737:chemistry*; D016877:Oxidants / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*; D059027:Recycling / Q000379:methods*; D012722:Sewage / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D001959:Bromates; D002712:Chlorides; D016877:Oxidants; D012722:Sewage; D014874:Water Pollutants, Chemical; D017967:Zinc Compounds; D010126:Ozone; C016837:zinc chloride; D019815:Oxalic Acid