【摘要】 用20 mL H2O2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,24 h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,1 h时由初始浓度0.05 mol/L降至0.000 3 mol/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。更多还原

【Abstract】 Heavily diesel-contaminated soil was oxidized with hydrogen peroxide.The effect of pH value of the soil with super-saturated water on the reaction were investigated.The results show that more than 96% of the diesel was degraded within 24 h when pH was about 5~8 for the soil with 5% initial oil content.The pH of the soil solutions reduced from 7.34,6.74,5.78 to 7.02,6.58,5.49 respectively throughout the reaction,which could be attributed mainly to the generation of acid species such as CO2,H+,carboxylic,and β-keto acids.The H2O2 concentration in the soil solution decreased greatly from 0.05 mol/L to close to 0 after 1 h.The diesel content in the surface layer varied but decreased in general,while the diesel content in the underlayer declined greatly,showing that the decomposition,volatilization and movement from bottom to top of diesel components occurred during the oxidation reaction.更多还原