摘要:
利用Cu作为催化金属与微米铁制成双金属体系处理主要污染物为六六六(HCH)和滴滴涕(DDT)的某污染场地土壤,探讨了不同表面活性剂(鼠李糖脂与Triton X-100(TX-100))对微米Fe/Cu双金属体系降解土壤中有机氯农药的影响。结果表明:相对于空白和只添加零价铁与微米Fe/Cu的三组的稳定,添加了两种表面活性剂的Fe/Cu双金属体系,35 d后土壤氧化还原电位(ORP)随时间呈缓慢上升趋势, Fe/Cu+TX-100至55 d时ORP由–400 mV升高到–300 mV;除Fe/Cu+鼠李糖脂组外,0~25 d内各组土壤pH随时间逐渐升高,从初始的5.0左右提高到6.5~7.2;微米Fe/Cu对污染物的降解效果相比零价铁有提高,鼠李糖脂与TX-100的投加能强化微米Fe/Cu对土壤中HCH和DDT的降解, TX-100的增强效果更为显著。当Fe投加量5%, Cu负载1%, TX-100浓度5 mmoL/L,初始pH 4.5时,处理55d后,α-HCH、γ-HCH、P, P’-DDD和P, P’-DDT的降解去除率达到100%、92.2%、95.7%和85.4%,总污染物去除率为90.0%。
Abstract:
The polluted soil with main pollutants as hexachlorocyclohexane (HCH) and dichloro-diphenyl-trichloroethane (DDT) was dechlorinated using the bimetallic system made of micron iron powder and Cu. And the effects of micron Fe/Cu with surface active agents (rhamnolipid and Triton X-100 (TX-100)) on dechlorination efficiency of polluted soil containing organic-chlorine pesticide were analyzed. The results showed that Oxidation-Reduction Potential(ORP)of polluted soil increased slowly with time 35 d after the addition of micron Fe/Cu, with both surface active agents comparing with micron Fe/Cu only and control experiment. ORP was raised from –400 mV to –300 mV 55 d after the addition of micron Fe/Cu with TX-100; pH increased with time during the first 25 d from 5.0 to 6.5~7.2 except for the addition of micron Fe/Cu with rhamnolipid; the bimetallic system made of micron Fe/Cu had more efficient dechlorination effect relative to zero-valent iron, and both surface active agents, especially TX-100, improved the dechlorination efficiency of micron Fe/Cu in polluted soil. The pollutants removal rate was 90.0% and the removal rates ofα-HCH,γ-HCH, P, P’-DDD & P, P’-DDT were 100%, 92.2%, 95.7% and 85.4%, respectively, 55 d after the addition of micron Fe (5%), Cu (1%) and TX-100 (5 mmoL/L) with initial pH at 4.5.
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