H_2O_2氧化法修复柴油污染土壤

用20mLH2O2氧化处理柴油重度污染土壤，研究了土壤含水量过饱和状态下pH值对反应的影响。结果表明，24h之内，5％初始含油量污土，pH值为5—8时，去油率在96％以上，即pH值近中性的土壤介质，在含水量过饱和情况下，处理条件相同时，其氧化去除效果差别不大；反应后溶液pH值由7．34、6．74、5．78降至7．02、6．58、5．49，这主要是由于一些酸性基团如CO2、H^＋、羧基、β-酮酸等的产生所致；反应溶液中H2O2量下降明显．1h时由初始浓度0．05mol／L降至0．0003mol／L左右，测出值趋近于0；表层油含量变化不稳定，但总趋势下降，下层油含量变化则呈明显下降趋势，说明整个氧化过程中柴油组分经历了分解、挥发和自下而上的迁移。

Diesel oil infiltration in soils with selected antecedent water content and bulk density

The effects of soil texture, initial water content and bulk density on diesel oil infiltration in fine sand and silty clay loam materials were evaluated. Three physical and two empirical equations express diesel oil infiltration through soils with time, with coefficients of determination greater than 0.99. Diesel oil infiltrates more quickly in the fine sand than in the silty clay loam material. Diesel oil infiltration rates are found to decrease with increasing initial water content and bulk density for the silty clay loam material. The infiltration rate of diesel oil in the fine sand material increases slightly with increasing initial water content. The diesel oil saturated conductivity(Kdiesel) decreases with increasing bulk density for the silty clay loam column. Diesel oil sorptivity(S) decreases linearly with increased initial water content and bulk density of the silty clay loam material. Changes in empirical parameters relative to initial water content and bulk density are similar to the parameter S.