黄山景区土壤重金属分布特征及其潜在生态风险评价

选取黄山风景区6条主要游览步道,采集70个土壤样品,用等离子发射光谱法测定其Zn、Cu、Pb、Cr、As和Ni的含量并分析其分布特征,应用潜在生态风险指数法对黄山风景区土壤重金属污染进行分析和评价。结果表明,黄山风景区土壤Zn、Cu、Pb、Cr、As、Ni的平均含量分别为157.02,19.73,46.44,41.46,29.47,10.26mg/kg,除Ni外,所有元素均超出土壤背景值。结合土壤重金属在不同景区的分布和样带上的横向分布规律以及相关性分析,得出Cu、Pb主要来源于汽车尾气排放物的沉降,在云谷景区和玉屏景区相对较高;Ni、Cr来源于地壳源,在样带的横向分布上呈逐渐增加的趋势;Zn在北海景区含量最高,受游客的旅游活动干扰最大;As可能由于农药的喷洒导致整个景区均存在一定程度的污染。黄山风景区土壤重金属整体处于轻微生态风险,各种重金属的潜在生态危害由强至弱依次为:As>Pb>Cu>Zn>Cr>Ni,其中,As是黄山景区土壤最主要的潜在生态风险因子。

Distribution Characteristics and Potential Ecological Risk Assessment of Heavy Metals in Soils of Huangshan Scenic

Selected 6 main tour trails in Huangshan scenic and collected 70 soil samples.Concentrations of Zn,Cu,Pb,Cr,As and Ni in the samples were determined using ICP-AES(Inductively Coupled Plasma-Atomic Emission Spectrometry).Distribution characteristics were analyzed and the potential ecological risk index was used to evaluate the pollution degree of heavy metals in Huangshan scenic.The results indicated that average content of Zn,Cu,Pb,Cr,As,Ni in soil in Huangshan scenic were 157.02,19.73,46.44,41.46,29.47,10.26 mg/kg.In addition to Ni,all the elements were beyond soil background value in Huangshan scenic.Combined with distribution rule in different area,transverse distribution rule of belt transect and correlation analysis of soil heavy metal,Cu and Pb were related to settlement of car exhaust emissions,Heavy metal concentrations of Baiyun scenic and Yupin scenic were higher than those in other scenics;Ni and Cr derived from earth crust,transverse distribution of belt transect presented the increasing trend.Maximum content of Zn appeared in Baihai scenic,mainly affected by tourism activities.As displayed certain degree of pollution in the whole scenic due to pesticide spraying.Heavy metals in the soils in Huangshan scenic are in a light potential ecological risk,the potential ecological risk was characterized by the order of As >Pb >Cu >Zn >Cr >Ni,and As was the predominant potential ecological risk factor.