O3/H2O2与O3/Mn氧化工艺去除水中难降解有机污染物的对比研究

以硝基苯为代表性有机污染物,对比研究了O₃/H₂O₂与O₃/Mn氧化工艺去除水中难降解有机污染物的效能与机理结果发现,2种催化氧化工艺均可以提高不易被单独臭氧氧化的硝基苯的去除效果,并且催化剂H₂O₂和Mn(Ⅱ)存在着最佳投量从已知的O₃/H₂O₂工艺反应机理,并根据硝基苯的化学性质和水中剩余臭氧动态监测结果推断,O₃/Mn降解硝基苯可能同样遵循自由基反应机理.向反应系统中投加H₂O₂和Mn(Ⅱ)还提高了臭氧的传质效果和有效利用率.对2种催化氧化工艺的特点和在实际水处理中应用进行了分析和探讨.

Comparative Study on O3/H2O2 and O3/Mn Processes for Removal of Refractory Organics in Water

A comparative study of O3/H2O2 and O3/Mn was made to evaluate their respective effectiveness and mechanism for removal of refractory organics from water with nitrobenzene as the model pollutant. It was found that both processes enhanced the degradation of nitrobenzene that can be hardly degraded by ozonation and had respective optimum dosage of H2O2 and Mn(II) under the experimental conditions. By comparing the mechanism of O3/H2O2 process and considering the chemical character of nitrobenzene and variation of residual aqueous ozone, it is speculated that the degradation of nitrobenzene by O3/Mn might follow a radical pathway. As shown by the experimental result, the addition of H2O2 and Mn(II) both improved the mass transfer efficiency of ozone and thus more ozone was consumed for degradation of nitrobenzene, which is also an indication of the radical type reaction mechanism. The characteristic of O3/H2O2 and O3/Mn processes and their application in the drinking water treatment were finally discussed.