为了解长江下游某化工园区公共区域表层土壤中的重金属分布特征、污染现状及污染来源, 在某化工园区公共区域共采集了514个表层土壤样品, 检测了11种元素浓度. 基于GIS (Geographic Information Systems)进行重金属浓度分布平面表征, 采用单因子指数、潜在生态风险指数、主成分分析 (principal component analysis, PCA) 和绝对主成分得分多元线性回归受体模型 (absolute principal component score multiple linear regression receptor model, APCS-MLR) 进行了研究分析. 研究结果表明: 化工园区公共区域表层土壤中除Cr(Ⅵ)低于检出限外, 其他10种重金属均有检出, 且均存在超背景值区域, 占比分别为Cu (86%) > Cd (71%) > Co (53%) > Ni (50%) > Be (45%) > As (42%) > Sb (40%) > Pb (23%) > V (16%) > Hg (4%) , 主要位于火力发电厂和垃圾焚烧厂周边. 研究区域表层土壤中Cd元素和Sb元素的生态风险指数较高, 且均存在极强 (Cd占比1.7%、Sb占比1.5%) 和很强 (Cd占比1.0%、Sb占比0.2%) 生态风险等级的区域, 均位于园区西北侧大型化工企业附近. 表层土壤中重金属复合生态风险指数属于中等生态危害, 存在着一定的生态危害风险. 研究区域表层土壤中的重金属污染来源主要包括化工源和燃烧源、自然源、交通源, 载荷量分别为27.2%、17.0%、11.0%.

This study investigated the heavy metal distribution characteristics, assess the pollution status, and identify potential pollution sources. A total of 514 topsoil samples were collected in the public area of the industrial park, and 11 element concentrations were tested. The concentration distribution of heavy metals was characterized on the plane using Geographic Information Systems (GIS). Our research involved the application of various analytical methods, including single factor index analysis, potential ecological risk index assessment, and principal component analysis-absolute principal component scores-multiple linear regression (PCA-APCS-MLR). The results revealed that all 10 heavy metals, except for Cr (Ⅵ) which was below the detection limit, were detected in concentrations surpassing the background values. The regional proportion were Cu (86%) > Cd (71%) > Co (53%) > Ni (50%) > Be (45%) > As (42%) > Sb (40%) > Pb (23%) > V (16%) > Hg (4%), and the concentrations of all major elements were relatively high. Moreover, there were areas with extremely strong (Cd element proportion was 1.7%, Sb element proportion was 1.5%) and very strong (Cd element proportion is 1.0%, Sb element proportion is 0.2%) ecological risk levels. They were all located near large chemical enterprises on the northwest side of the park. The composite ecological risk index of heavy metals in surface soil belonged to moderate ecological hazards, and there was a certain degree of ecological hazard risk. The main heavy metal pollution sources in the surface soil of the study area included chemical and combustion sources, natural sources, and transportation sources, accounting for 27.2%, 17.0%, and 11.0% of the pollution load, respectively.