Yang Liyuan, Wang Longfeng, Wang Yunqian, Zhang Wei
Department of Resources and Environment, University of Jinan, Jinan, 250022, China,
Environ Monit Assess. 2015 May;187(5):261. doi: 10.1007/s10661-015-4480-z. Epub 2015 Apr 17.
Sixteen surface sediment samples were collected from Nansi Lake to analyze geochemical speciation of heavy metals including Cd, As, Pb, Cr, and Zn, assess their pollution level, and determine the spatial distribution of the non-residual fraction. Results showed that Cd had higher concentrations in water-soluble and exchangeable fractions. As and Pb were mainly observed as humic acid and reducible fractions among the non-residual fractions, while Cr and Zn were mostly locked up in a residual fraction. The mean pollution index (P i) values revealed that the lower lake generally had a higher enrichment degree than the upper lake. Cd (2.73) and As (2.05) were in moderate level of pollution, while the pollution of Pb (1.80), Cr (1.27), and Zn (1.02) appeared at low-level pollution. The calculated pollution load index (PLI) suggested the upper lake suffered from borderline moderate pollution, while the lower lake showed moderate to heavy pollution. Spatial principle component analysis showed that the first principal component (PC1) including Cd, As, and Pb could explain 56.18 % of the non-residual fraction. High values of PC1 were observed mostly in the southern part of Weishan Lake, which indicated greater bioavailability and toxicity of Cd, As, and Pb in this area.
从南四湖采集了16个表层沉积物样本，以分析镉、砷、铅、铬和锌等重金属的地球化学形态，评估其污染水平，并确定非残留部分的空间分布。结果表明，镉在水溶性和可交换态部分的浓度较高。在非残留部分中，砷和铅主要以腐殖酸态和可还原态存在，而铬和锌大多以残留态存在。平均污染指数（Pi）值表明，较低湖区的富集程度总体上高于较高湖区。镉（2.73）和砷（2.05）处于中度污染水平，而铅（1.80）、铬（1.27）和锌（1.02）的污染处于低污染水平。计算得出的污染负荷指数（PLI）表明，较高湖区处于边缘中度污染，而较低湖区显示为中度至重度污染。空间主成分分析表明，包括镉、砷和铅的第一主成分（PC1）可以解释非残留部分的56.18%。PC1的高值大多出现在微山湖的南部，这表明该区域镉、砷和铅的生物有效性和毒性更高。
