焦化厂污染场地表层土壤有机-矿质复合体中多环芳烃的分布  

Distribution of polycyclic aromatic hydrocarbons in organo-mineral aggregates of topsoil from a coking plant contaminated site

作　　者：赵芳妮[1,2] 田文杰[2,3,4] 汪群慧[1] 李发生[2] 

机构地区：[1]北京科技大学土木与环境工程学院,北京100083 [2]中国环境科学研究院环境基准与风险评估国家重点实验室,北京100012 [3]洛阳理工学院环境工程与化学系,洛阳470123 [4]中国矿业大学(北京)化学与环境工程学院,北京100083

出　　处：《环境化学》2012年第8期1195-1200,共6页Environmental Chemistry

基　　金：国家自然科学基金项目(20977088)资助

摘　　要：采用湿法物理分级方法将湖南省某焦化厂遗留场地表层土壤分成4种粒级的有机-矿质复合体组分,即粘粒(<2μm)、粉粒(2—20μm)、细砂(20—200μm)和粗砂(>200μm),并研究了美国EPA优先控制的16种多环芳烃(PAHs)在其中的分布特征及土壤不同有机-矿质复合体组分中有机质和矿物质组成的差异对PAHs赋存分布的影响.研究结果表明,不同粒级有机-矿质复合体中PAHs的含量顺序为粗砂>粉粒>细砂>粘粒,低环PAHs(环数≤3)在粘粒中的含量较高,达到56.3%,而高环PAHs(环数≥4)在粉粒、细砂和粗砂中的分布较高含量分别是79.37%、72.7%和71.63%,各粒级矿质复合体中PAHs含量与土壤有机碳有较好的相关性.通过对有机-矿质复合体进行X射线衍射分析发现,场地土壤粘粒和粉粒中粘土矿物含量较高,这也在一定程度上影响了污染物质在其中的分布.In this paper,four different soil particle-size fractions from the topsoil in a coking plant contaminated site,i.e.,clay（2 μm）,silt（2—20 μm）,fine sand（20—200 μm） and coarse sand（200 μm）,were separated by wet physical classification method.And the distribution of 16 polycyclic aromatic hydrocarbons（PAHs） in US EPA priority list was analyzed to investigate the effect of soil organic matter and mineral composition on the difference of PAHs distribution.The results showed that the concentrations of PAHs increased in the order of coarse sand siltfine sandclay.The content of PAHs with less than 3 aromatic rings was higher in clay,while PAHs with more than 4 rings had higher contents in the other fractions.Strong positive correlation between total PAHs concentration and TOC was observed.The analysis on X-ray diffraction of organo-mineral aggregates demonstrated that the contents of the clay mineral in clay and silt aggregates were higher than in the other fractions.PAHs distribution in organo-mineral aggregates was related to the difference in the content and composition of the clay minerals.

关 键 词：焦化厂 污染场地 表层土壤 有机-矿质复合体 多环芳烃 

分 类 号：X833[环境科学与工程—环境工程]