再生铝企业周边农田土壤与农作物重金属含量特征分析

为探究再生铝企业群周边农田土壤及作物的污染状况,通过现场采样及室内测试,对企业周边土壤及农作物中7种重金属元素的含量进行分析,应用空间插值法对土壤重金属的空间分布特征进行研究。结果表明,研究区域土壤中Cd含量相对较高,含量范围为0.11~1.86 mg·kg^-1,其平均值超过了我国土壤污染风险筛选值标准,Cu、Cr、Zn、Pb、Cd、Ni和As 7种元素的平均值分别达到河北省背景值的1.9、1.1、1.4、1.5、4.1、0.91倍和0.39倍,Cd元素存在强生态风险。从空间分布特征来看,土壤中Cd、Pb、Cu、Zn 4种元素均表现出以企业为中心向四周逐渐递减的分布趋势,且高值分布范围相对其他金属较广。小麦籽粒中Cu、Zn、Cd、Cr和Pb 5种元素存在不同程度的超标现象,最严重的为元素Pb,其含量范围为0.02~1.06 mg·kg^-1,与食品安全国家标准相比,最大超标倍数达到5.3倍,其高值样品分布在研究区北部。玉米籽粒也发现Cr、Zn、Ni超标的现象,Cr超标较其他重金属严重,其含量范围为0.16~1.32 mg·kg^-1。研究表明,再生铝企业活动对周边农田土壤和农作物造成多种重金属污染威胁,需要引起重视。

Analysis on characteristics of heavy metals content in farmland soils and crops around recycled aluminum enterprises

To explore the pollution status of agricultural soils and crops around a recycled aluminum enterprise group, the concentration of seven heavy metal elements in the soils and crops around such an enterprise were analyzed through sampling and laboratory tests. Furthermore, the spatial distribution characteristics of soil heavy metals were studied by spatial interpolation. The results showed that the concentration of Cd in the soil of the study area was relatively high and the concentration ranged from 0.11 to 1.86 mg·kg^-1. The average concentration of Cd was higher than the screening value of soil pollution risk in China. The average concentrations of Cu, Cr, Zn, Pb, Cd, Ni, and As were 1.9, 1.1, 1.4, 1.5, 4.1, 0.91, and 0.39 times of the background values of Hebei Province, respectively; the Cd concentration presented a strong ecological risk. From the distribution characteristics, the Cd, Pb, Cu, and Zn in the soil gradually decreased from the enterprise to the periphery and the distribution range is wider than the other metals. Moreover, Cu, Zn, Cd, Cr, and Pb in wheat grains were higher than the standard values. The Pb concentration was relatively high and the concentration range was 0.02 to 1.06 mg·kg^-1. Compared with the National Food Safety Standards, the maximum concentration of Pb was 5.3 times of the standard value; the high concentration samples were distributed in the northern part of the study area. In corn kernels, the concentrations of Cr, Zn, and Ni were also higher than the standard values. The Cr concentration was higher than other heavy metals, ranging from 0.16 to 1.32 mg·kg^-1. The research results showed that the activities of recycled aluminum enterprises have caused a variety of heavy metals pollution in the surrounding agricultural soils and crops. This situation needs to be taken seriously considering the effects of this pollution.