工业区周边农田重金属污染评价及来源分析

Heavy Metal Pollution Assessment and Source Analysis on Farmland Soil around an Industrial Area

以新疆北疆某工业区周边农田土壤为研究对象,采集0~20 cm土壤样品254个,测定了Cr、Ni、Cu、Zn、As、Hg、Pb、Cd共8种重金属含量。运用相关性分析和主成分分析探讨工业区周边农田土壤重金属的来源,运用GS+进行数据拟合,选取最佳模型,再进行克里格插值分析重金属的空间分布格局。结果表明,Cr、Ni、Cu、Zn、As、Hg、Pb和Cd的含量分别为45.00、28.53、55.66、73.57、13.39、2.17、15.38和0.50 mg kg^(-1)。测量的金属除Cr之外均超过土壤的背景值,只有Hg处于中度污染,其余元素都处于非污染,而研究区综合潜在生态风险程度为严重型。重金属空间分布表明,Ni、Zn、As、Hg和Pb在东部和南部含量较高。来源分析表明,Hg来源受研究区内工业活动的影响;Cr、Ni、Zn和Cd主要来自于化肥、农药和地膜等农业活动和土壤母质的共同作用;As、Hg和Pb主要来源是受研究区内工业活动的影响。

Farmland soil around an industrial area in the north of Xinjiang was studied. A total of 254 soil samples were taken from the 0 - 20 cm layers, and the contents of Cr, Ni, Cu, Zn, As, Hg, Pb and Cd were tested, respectively. The correlation analysis and principal component analysis were used to identify the sources of these heavy metals in soils. Data fitted and best model selected by GS＋. Spatial distribution of heavy metals in the study area analyzed by ArcGIS10.1. The results showed that the contents of Cr, Ni, Cu, Zn, As, Hg, Pb and Cd in the study area were 45.00, 28.53, 55.66, 73.57, 13.39, 2.17, 15.38 and 0.50 mg kg^-1, respectively. Heavy metals, except Cr, exceeded their background values. Soil was polluted by Hg in middle level, and not polluted by other heavy metals. But the comprehensive potential ecological risk in the study area was serious. The spatial distribution of heavy metals showed that Ni, Zn, As, Hg and Pb were obviously enriched in the east and south of Xinjiang. Source analysis showed that the source of Hg might be influenced by the industrial activity. The source of Cr, Ni, Zn and Cd may be affected by agricultural activities and soil parent material together. The source of As, Hg and Pb might be mainly related to industrial activities.