矿物催化臭氧氧化乙硫氨酯的效率和矿化行为研究

浮选废水中残留固体悬浮物具有催化臭氧氧化作用，考察了四种硫化矿（黄铁矿、黄铜矿、方铅矿及闪锌矿）和四种非金属矿（石英、方解石、高岭土及蒙脱土）对臭氧氧化乙硫氨酯效率的影响及矿化行为。结果表明，矿物强化臭氧氧化乙硫氨酯降解效率高低顺序为方铅矿>黄铁矿>闪锌矿>黄铜矿（硫化矿）和高岭土>蒙脱土>方解石>石英（非金属矿），投加0.5 g/L方铅矿和高岭土后，乙硫氨酯降解速率常数分别提高了1.57倍和0.82倍，明显促进乙硫氨酯降解和中间产物的分解；降解后溶液pH值从10.0降至约8.0，氧化还原电位从-23 mV上升到约200 mV。矿物颗粒促进臭氧分解，生成更多强氧化性物种，提高降解效率，浮选废水中残留矿物颗粒是天然臭氧分解催化剂，可构成催化臭氧氧化体系。 

Removal Efficiency and Mineralization in Catalytic Ozonation of O-isopropyl-N-ethyl Thionocarbamate by Minerals in Flotation Wastewaters

Residual minerals in flotation wastewaters can promote the degradation of pollutants by the catalytic ozonation. In this work, the catalytic ozonation of O-isopropyl-N-ethyl thionocarbamate (Z-200) was investigated by sulfide minerals (pyrite, chalcopyrite, galena and sphalerite) and nonmetallic minerals (quartz, calcite, kaoline and montmorillonite), respectively. The results indicated that the dosage of minerals could increase the decomposition efficiency of Z-200 collector with an enhancement order of galena > pyrite > sphalerite > chalcopyrite (sulfide minerals) and kaoline > montmorillonite > calcite > quartz (nonmetallic minerals). In particular, the decomposition rate constant of Z-200 increased by 1.57 and 0.82 folds for the dosage of 0.5 g/L galena and kaoline into O₃ system, respectively. The O₃/mineral systems could enhance the decomposition of both Z-200 and its byproducts compared to O₃-alone. After the decomposition of Z-200, solution pH reduced from 10.0 to about 8.0 and the redox potential increased from -23 to about 200 mV. The mineral particles can promote the decomposition of O₃ molecules, generating much higher amounts of oxidative species. Mineral particles in flotation wastewaters are natural catalysts to form the catalytic ozonation systems in the removal of flotation reagents.