Liu Shuo, Wu Quan-yuan, Cao Xue-jiang, Wang Ji-ning, Zhang Long-long, Cai Dong-quan, Zhou Li-yuan, Liu Na
Huan Jing Ke Xue. 2016 Jan 15;37(1):270-9.
The present paper takes the coal mining area of Longkou City as the research area. Thirty-six topsoil (0-20 cm) samples were collected and the contents of 5 kinds of heavy metals were determined, including Cd, As, Ni, Ph, Cr. Geo-statistics analysis was used to analyze the spatial distribution of heavy metals. Principal component analysis (PCA) was used to explore the pollution sources of heavy metals and the degree of heavy metals pollution was evaluated by weighted average comprehensive pollution evaluation method. The results showed that enrichment phenomenon was significant for the 5 kinds of heavy metals. Taking secondary standard of National Environment Quality Standard for Soil as the background value, their exceed standard rates were 72.22%, 100%, 100%, 91.67%, 100%, respectively. Average contents of heavy metals in the soil samples were all over the national standard level two and were 1.53, 11.86, 2.40, 1.31, 4.09 times of the background value. In addition, the average contents were much higher than the background value of the topsoil in the eastern part of Shandong Province and were 9.85, 39.98, 8.85, 4.29, 12.71 times of the background value. According to the semivariogram model, we obtained the nugget-effects of 5 kinds of heavy metals and their values were in the order of As (0.644) > Cd (0.627) > Cr (0.538) > Ni (0.411) > Pb (0.294), all belonging to moderate spatial correlation. On the whole, the central part of the Sangyuan Coal Mine and its surrounding areas were the most seriously polluted, while the pollution of heavy metals in the east and west of the study area was relatively light. Principal component analysis suggested that the enrichment of Cd, As, Ni, Cr was due to irrigation of wastewater, the discharge of industry and enterprise, and the industrial activity. Automobile exhaust and coal combustion were the main pollution sources of Pb. The single-factor assessment of heavy metals pollution showed that the degree of different heavy metals pollution was in the order of As > Cr > Ni > Cd > Pb. Simultaneously, comprehensive pollution evaluation showed that the degree of heavy metals pollution in the study area was very serious, with comprehensive pollution index ranging from 2.17 to 4.66, among which, the numbers of moderate and heavy pollution samples were 10 and 26, respectively. Areas with heavy pollution were mainly distributed in the Sangyuan Coal Mine, Beizao Coal Mine, Liuhai Coal Mine; and the areas with moderate pollution covered Wali Coal Mine, Liangjia Coal Mine, and other regions. The results of this paper will provide data reference and theoretical support for the study of ecological risk assessment in the study area.
本文以龙口市煤矿区为研究区域。采集了36份表层土壤（0 - 20厘米）样本，测定了其中镉（Cd）、砷（As）、镍（Ni）、铅（Pb）、铬（Cr）5种重金属的含量。采用地统计学分析方法分析重金属的空间分布情况。运用主成分分析（PCA）探究重金属的污染源，并采用加权平均综合污染评价法对重金属污染程度进行评价。结果表明，5种重金属均存在显著的富集现象。以《土壤环境质量标准》二级标准作为背景值，其超标率分别为72.22%、100%、100%、91.67%、100%。土壤样本中重金属的平均含量均超过国家二级标准水平，分别是背景值的1.53倍、11.86倍、2.40倍、1.31倍、4.09倍。此外，这些平均含量远高于山东省东部地区表层土壤的背景值，分别是背景值的9.85倍、39.98倍、8.85倍、4.29倍、12.71倍。根据半变异函数模型，得出5种重金属的块金效应，其大小顺序为砷（As，0.644）＞镉（Cd，0.627）＞铬（Cr，0.538）＞镍（Ni，0.411）＞铅（Pb，0.294），均属于中等空间相关性。总体而言，三元煤矿中部及其周边区域污染最为严重，而研究区域东部和西部的重金属污染相对较轻。主成分分析表明，镉、砷、镍、铬的富集是由于废水灌溉、工业企业排放以及工业活动所致。汽车尾气排放和煤炭燃烧是铅的主要污染源。重金属污染的单因子评价表明不同重金属污染程度顺序为砷＞铬＞镍＞镉＞铅。同时，综合污染评价表明研究区域重金属污染程度非常严重，综合污染指数在2.17至4.66之间，其中，中度污染和重度污染样本数量分别为10个和26个。重度污染区域主要分布在三元煤矿、北皂煤矿、刘海煤矿；中度污染区域包括洼里煤矿、梁家煤矿等地区。本文研究结果将为研究区域的生态风险评估提供数据参考和理论支持。
