基于受体模型和地统计学相结合的土壤镉污染源解析

Source apportionment of soil heavy metal Cd based on the combination of receptor model and geostatistics

研究了武汉市东湖高新技术开发区约150km2范围内土壤重金属Cd元素的含量分布和潜在来源情况.并利用主成份分析/绝对主成分分数(PCA/APCS)受体模型定量解析了土壤中Cd的来源,结果表明土壤中Cd的来源以源1为主(来源分担率为:源167%、源28%、源316%,其他源9%).同时利用该受体模型得到了在每个采样点的源贡献量,并用地统计学方法插值了Cd的源贡献量的空间分布状况.结果显示,Cd各个源贡献量具有不同的空间分布状况,其中最大源1的高贡献值主要集中在研究区中部.结合PCA分析和源贡献量空间分布状况,初步推断源1可能为电子工业源,源2为城市大气沉降,源3应为成土母质.研究结果表明,将PCA/APCS受体模型和地统计学方法相结合可以有效地对土壤重金属隐性污染源进行定性识别及定量解析.

The principal component analysis/absolute principal component scores （PCA/APCS） receptor model and the ordinary kriging interpolation method were combined to identify and apportion the pollution sources of soil Cd in an area of about 150 km2 in the Wuhan Donglau High-tech Development Park. Four sources and their contribution rates, obtained using the receptor model, were as follows： source I （67%）, source II （8%）, source IIl （16%） and other sources （9%）. Source contributions at each sampling site were further quantified using the receptor model, and the spatial distribution patterns of the contributions of different sources to soil Cd were mapped using ordinary kriging interpolation. Results show that every Cd source had its unique spatial pattern and high contributions from the largest Cd source （source I） mainly concentrated in the central region of the study area. Based on PCA analysis and the spatial distribution patterns of the source contributions, source I may originate from the electronic industry, source II may come from urban atmospheric deposition, particularly vehicle gas emission, and source III should be soil parent materials. This study indicates that combining the PCA/APCS receptor model and geostatistics is an effective method for apportioning heavy metal pollution sources.