模拟酸雨对工业污染场地表层土壤中多环芳烃释放的影响

通过工业污染场地表层土壤的模拟酸雨浸泡试验,分析了不同酸度的模拟酸雨浸泡前后土壤中有机质、EPA优先控制的16种多环芳烃含量和矿物质组成的变化.研究结果表明,酸雨浸泡前后土壤矿物相组成相似,主要以石英为主,只是在矿物组成的量上存在差别,浸泡后土壤中赤铁矿和粘土矿物的含量较浸泡前有所减少.模拟酸雨浸泡后土壤中有机质和多环芳烃均有不同程度的释放,酸雨pH值越小,释放量越大,且多环芳烃可能是随着有机质一起释放的;酸雨对土壤中不同性质多环芳烃释放的影响不同,对低环多环芳烃（环数≤3）释放的影响较大,对高环多环芳烃（环数≥4）影响较小.研究结果为理解在酸雨作用下工业污染场地土壤中多环芳烃的释放规律及土壤中多环芳烃稳定性研究提供一些科学依据.

Effects of simulated acid rain on the release of polycyclic aromatic hydrocarbons from topsoils of an industrially contaminated site

A laboratory soaking experiment on topsoils from an industry contaminated site was carried out using simulated acid rain,in which change of soil organic matter(SOM),concentration of polycyclic aromatic hydrocarbons(PAHs) and mineral composition before and after soaking by simulated acid rain were analyzed.The results showed that the soil mineral was found to exhibit similar composition before and after soaking.The main component was quartz.However,the percentage of each mineral component was different,and the hematite and clay mineral decreased after soaking when compared to the original soil.Soil organic matter and polycyclic aromatic hydrocarbons were released from the soil soaked by simulated acid rain,and the release quantity increased with the decrease of acid rain pH.PAHs associated with SOM were released from topsoils under simulated acid rain.The effect of acid rain on the release of different PAHs from topsoils was different.And acid rain had greater influence on the release of low-aromatic ring PAHs(≤3),while its influence was less for high-aromatic ring PAHs(>4).The results may help to understand the release pattern of PAHs from topsoils in an industrially contaminated site under acid rain and provide the scientific support for research of PAHs stability in soil under acid rain.