溶液吸收结合铁碳微电解法降解模拟废气中二氯甲烷

Degradation of dichloromethane by absorption combined with iron-active carbon micro-electrolysis

采用管式反应器,以铁屑和活性炭为填料,溶液吸收结合铁碳微电解反应处理废气中二氯甲烷(DCM)。实验对比了采用铁屑、活性炭和铁屑-活性炭(Fe-C)混合填料3种条件下对DCM的去除效果,表明采用Fe-C混合填料的DCM去除率要高于单独采用铁屑或活性炭作为填料的情况,同时发现Fe-C体系组成的溶液的氧化还原电位(ORP)从反应开始急剧下降,与其他两种条件下有明显的区别;降低溶液初始pH能提高Fe-C体系DCM的脱氯和降解效果,在pH=1.5的条件下,Cl-生成率达最大为2.85%。通过气相色谱仪对反应进出口气体的分析,发现反应后产物主要为甲烷。

The removal of dichloromethane by absorption combined with iron-active carbon micro-electrolysis in a tube reactor filled respectively with iron mash, activate carbon particle and combined iron-active carbon （Fe-C）, was investigated. The result shows that removal of DCM is higher for Fe-C mixed packing than for iron mash or activate carbon one. Oxidation Reduction Potential（ORP） of solution in the reactor filled with Fe-C mixed packing rapidly drops, which can create a more reducing environment at around 180 mV, while for other two fillers there is significant difference. It was also found that removal and dechlorination of DCM can be enhanced when pH of aqueous solution decreases. After 300 min the C1- concentration in solution is about 4 times higher at pH 1.5 than at pH 5, and the maximum rate of C1- generation is 2.85%. The gaseous product from dechlorination of dichloromethane by Fe-C is mainly methane.