γ-Al2O3催化臭氧氧化水中嗅味物质机理探讨

以γ-Al₂O₃粉末为催化剂,研究催化臭氧氧化去除水体中典型嗅味物质2-甲基异茨醇（MIB）的效能与机理.结果表明,γ-Al₂O₃能够明显促进臭氧氧化去除MIB,表现出很好的催化活性,叔丁醇对γ-Al₂O₃催化氧化去除MIB过程具有明显的抑制作用.在催化臭氧氧化去除MIB过程中,γ-Al₂O₃表面电荷状态及表面羟基的带电性质与溶液的pH值有关.当溶液pH值与γ-Al₂O₃ 的pH_zpc接近时,γ-Al₂O₃的催化作用最为明显.γ-Al₂O₃催化臭氧氧化过程中自由基的相对量值R_ct比单独臭氧氧化过程高出近1个数量级,这进一步表明γ-Al₂O₃能明显促进臭氧分解产生更多的羟基自由基.最后还考察了不同摩尔比例的臭氧分解促进剂与抑制剂对γ-Al₂O₃催化臭氧分解的影响.

Mechanism discussion of gamma-alumina catalyzed ozonation for 2-methylisoborneol removal

The efficiency and mechanism in degradation of 2-methylisoborneol (MIB) as taste and odor compound in drinking water were studied under the condition where gamma-alumina catalyzed ozonation. As a result, gamma-alumina can behave distinct activity in enhancing the efficiency of ozonation MIB. Tert-butyl alcohol had a remarkable restrain effect on removal efficiency of catalytic ozonation MIB by gamma-alumina. The surface charge status and surface hydroxyl groups status of gamma-alumina and pH values of the solution can be linked together. When the pH value of solution was near the pH(zpc) of gamma-Al2O3, there was a most observable activity in catalyzed ozonation process. R(ct), which denoted the relative concentration of hydroxyl radical (*OH), was much higher in catalyzed ozonation process than in ozonation process. This result further illuminated that gamma-Al2O3 can promote ozone decomposition to produce *OH. Finally, it was investigated that the effect of r(P/I) on catalyzed ozone decomposition and ozone decomposition.