山东省临沭县北部农用地土壤重金属分布特征及生态风险评价

Distribution Characteristics and Ecological Risk Assessment of Heavy Metals in Agricultural Soil in Northern Linshu County in Shandong Province

摘要:

本文以山东省东南部的临沭县北部农用地表层土壤为研究对象，分析了土壤中8种重金属元素含量及其分布特征，采用地积累指数法和潜在生态风险指数法评价了研究区农用地土壤重金属生态风险。结果表明：8种重金属中除Pb元素略高于临沂市表层土壤背景值外其余7种元素都低于背景值，研究区表层土壤中金属累积程度整体上相对较轻，土壤中重金属地积累程度由强到弱顺序为Hg＞As＞Zn＞Cd＞Cu＞Ni＞Cr＞Pb，Hg元素有0.30%的样品属于中度累积以上级别，是累积程度最严重的元素，在局部可能存在一定程度的严重污染状况。Cr、Cu、Ni、Pb、Zn这5种元素的单因子潜在生态风险较小，Hg和Cd为单因子潜在生态风险评价重危害程度最严重的2种元素，综合潜在生态风险指数有72件样品达到了中度风险等级以上，这种现象主要受Hg和Cd这2种元素的影响。该研究成果可为该地区农产品产地安全管理和农业可持续发展提供重要科学依据。

Abstract:

In this paper, taking agricultural surface soil in the northern part of Linshu county in southeastern Shandong province as the research object, the content and distribution characteristics of 8 heavy metal elements in the soil have been analyzed, and the ecological risk of heavy metal in the agricultural soil in the study area have been evaluated by using land accumulation index method and the potential ecological risk index method. As showed by the results, among 8 heavy metals, except for Pb element, which is slightly higher than the background value of the surface soil in Linyi city, the remaining 7 elements are all lower than the background value. The overall accumulation of metals in the surface soil of the study area is relatively light, and the order of heavy metal accumulation in the soil from strong to weak is Hg>As>Zn>Cd>Cu>Ni>Cr>Pb. 0.30% of the samples with Hg element belong to the level of moderate accumulation or above, making them the most severely accumulated elements. There may be a certain degree of severe pollution locally. The single factor potential ecological risk of five elements, such as Cr, Cu, Ni, Pb, and Zn is relatively small. Hg and Cd are the two elements with the most severe degree of harm in the single factor potential ecological risk assessment. The comprehensive potential ecological risk index shows that 72 samples have reached a moderate risk level or above, which is mainly influenced by the two elements Hg and Cd. The research results can provide important scientific basis for the safety management of agricultural product production areas and sustainable agricultural development in the region.