Accelerated TiO₂ photocatalytic degradation of Acid Orange 7 under visible light mediated by peroxymonosulfate

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• 作者：Xiaoyang Chen ^{xiaoyangchen@yahoo.cn} ; Weiping Wang ; Hua Xiao ; Chunlai Hong ; Fengxiang Zhu ; Yanlai Yao ; Zhiyong Xue ; ^{zhiyongxue@yahoo.cn}
• 关键词：Wastewater ; Azo dye ; Sulfate radicals ; Dye sensitization ; Photocatalysis ; Peroxymonosulfate
• 刊名：Chemical Engineering Journal
• 出版年：2012
• 出版时间：15 June, 2012
• 年：2012
• 卷：193-194
• 期：Complete
• 页码：290-295
• 全文大小：675 K

文摘

In this study, a system involving visible light TiO₂ photocatalysis (Vis/TiO₂) coupled with -based advanced oxidation technologies (AOTs) through the addition of the oxidant peroxymonosulfate (PMS, ) has been developed to oxidize the target pollutant Acid Orange 7 (AO7) in aqueous solutions. There existed a remarkable synergistic effect in the combined Vis/TiO₂/PMS system, and the performance of this combined system was better than that of a system to which persulfate (PS, ) or hydrogen peroxide (H₂O₂) was added. The influence of humic acids (HAs) and inorganic anions ( and ) on the degradation rates in the Vis/TiO₂/PMS system was also investigated. The obtained results revealed that HAs had a positive effect on the AO7 degradation efficiency in the Vis/TiO₂/PMS system. When added to the Vis/TiO₂ system, PMS can abrogate the adverse interference of anions in this system, such that the Vis/TiO₂/PMS system exhibits much better degradation rates. The primary degradation intermediates of AO7 identified by GC/MS were phthalic acid, 2,4,6-trichlorophenol, coumarin and two chlorinated aromatic compounds (7-chloro-2-naphthalenol and 2,4-dichloro-1-naphthalenol). A possible pathway was proposed based on the analysis of the degradation products.