title: Degradation of Acid Orange 7 in aqueous solution by dioxygen activation in a pyrite/H₂O/O₂ system.
abstract: Increasing attention has been paid to pyrite due to its ability to generate hydroxyl radicals in air-saturated solutions. In this study, the mineral pyrite was studied as a catalyst to activate molecular oxygen to degrade Acid Orange 7 (AO7) in aqueous solution. A complete set of control experiments were conducted to optimize the reaction conditions, including the dosage of pyrite, the AO7 concentration, as well as the initial pH value. The role of reactive oxygen species (ROS) generated by pyrite in the process was elucidated by free radical quenching reactions. Furthermore, the concentrations of Fe(II) and total Fe formed were also measured. The mechanism for the production of ROS in the pyrite/H2O/O2 system was that H2O2 was formed by hydrogen ion and superoxide anion (O2(·-)) which was produced by the reaction of pyrite activating O2 and then reacted with Fe(II) dissolved from pyrite to produce (·)OH through Fenton reaction. The findings suggest that pyrite/H2O/O2 system is potentially practical in pollution treatment. Moreover, the results provide a new insight into the understanding of the mechanism for degradation of organic pollutants by pyrite.
authors: University of Jinan, Jinan, China.
authors: Feifei
authors: F
authors: Hao
authors: Weilin
authors: W
authors: Guo
authors: Xin
authors: X
authors: Lin
authors: Yanqiu
authors: Y
authors: Leng
authors: Anqi
authors: A
authors: Wang
authors: Xinxin
authors: X
authors: Yue
authors: Liangguo
authors: L
authors: Yan
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D001557:Benzenesulfonates / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008956:Models, Chemical; D010100:Oxygen / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry*; D013481:Superoxides / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; D001557:Benzenesulfonates; D017382:Reactive Oxygen Species; D013440:Sulfides; D014874:Water Pollutants, Chemical; D013481:Superoxides; C011342:pyrite; D017665:Hydroxyl Radical; D006861:Hydrogen Peroxide; D007501:Iron; C014722:2-naphthol orange; D010100:Oxygen