臭氧氧化分解饮用水中嗅味物质2-甲基异莰醇

比较了几种常见氧化剂对饮用水中嗅味物质2-甲基异莰醇(2-methylisoborneol,MIB)的氧化去除效果.结果表明,KMnO₄、NaClO、H₂O₂等氧化剂的氧化作用对水中MIB的去除效果均较差,而臭氧却能有效地将其氧化;考察了pH对臭氧化去除MIB的影响规律,发现pH在7.0～10.0条件下,随着pH值增加MIB去除率增加,但当pH达到10.0左右时,MIB的去除率反而下降;MIB的臭氧化去除效果随着自由基捕获剂(重碳酸盐和叔丁醇)的浓度增加而明显地降低,说明臭氧化去除水中MIB主要遵循自由基作用机理;以松花江江水为本底进行试验和与蒸馏水进行试验的结果相差不大,原因可能是由于松花江水体中碳酸盐浓度较低(小于50 mg/L),对自由基捕获能力较小,同时江水中的部分腐殖质(NOM)对臭氧去除MIB的过程起到了促进作用.

Removal of 2-Methylisoborneol in Drinking Water by Ozonation

The removal efficiencies of 2-methylisoborneol(MIB) by KMnO4, NaClO, H2O2, O3 were compared, and it was found that ozone was the most effective oxidant for MIB removal. By investigating the factors of the removal of MIB by ozone, it was found that the removal of MIB increased with pH increase. And MIB was removed more than 90 % after 20min when pH was 7.0- 10.0. But MIB removal efficiency decreased when pH reached 10.0. However, it decreased in the presence of bicarbonate and tert-butanol that scavenge *OH in water. It indicated that MIB degradation mainly followed radical mechanism. The removal efficiency of MIB in Songhua River was almost the same as the results obtained in distilled water. One possible reason is that the carbonate concentration is low(less than 50 mg/L), in that way, OH may be less scavenged. Also, NOM may promote the removal of MIB by ozone in Songhua River.