汾河临汾段污灌区土壤重金属污染评价

摘要

为全面了解汾河临汾段污灌区土壤重金属污染状况，对该区土壤 Zn、Cu、Ni、Pb、Cd、Cr、Hg、As含量进行检测，并采用地累积指数法和潜在生态危害指数法对土壤重金属污染进行评价。结果表明，汾河临汾段污灌区土壤Zn、Cu、Pb、Cd、Hg、As 平均含量均超过了山西省土壤背景值；各重金属平均含量均未超过国家土壤环境质量标准二级标准值，仅 Ni、Pb、As 分别有5％、37％、1％的采样点超过了国家土壤环境质量标准二级标准值，但所有样点均未超过国家土壤环境质量标准三级标准值。汾河临汾段污灌区土壤各重金属地累积指数表现为 Hg＞Cd＞Pb＞Cu＞Zn＞As＞Ni＞Cr，各重金属潜在生态危害系数表现为 Hg＞Cd＞Pb＞As＞Cu＞Ni＞Cr＞Zn，土壤环境总体处于无至中－强度污染水平，存在强度危害风险。污染较严重的重金属元素不仅受灌溉水质影响，还与灌溉次数、农业施肥、交通运输、工矿企业生产、日常生活和生产活动密切相关。%In order to determine the pollution condition of heavy metal in the soil of sevage irrigation region of Fen River in Linfen area,the contents of Zn,Cu,Ni,Pb,Cd,Cr,Hg and As in this area were analyzed,and the potential ecological risk index and geoaccumulation index were used to evaluate the degree of heavy metal contamination in soil.The results indicated that the average contents of Zn,Cu,Pb,Cd,Hg and As were higher than the background values of that in Shanxi soil;the average contents of Zn,Cu,Ni,Pb,Cd,Cr,Hg and As were lower than the second class limit value of that in the nation standard for soil environment quality,except the content of Ni in 5% sampling points,the content of Pb in 3 7% sampling points and the content of As in 1%sampling points;the average contents of Zn,Cu,Ni,Pb,Cd,Cr,Hg and As were lower than the third class limit value of that in the nation standard for soil environment quality in all sampling points.The geoaccumulation index order was Hg>Cd>Pb>Cu>Zn>As>Ni>Cr,the potential ecological risk index order was Hg>Cd>Pb>As>Cu>Ni>Cr>Zn,the pollution level was no to moderate-strong pollution level,the risk intensity was strong.Heavy metals with high levels of pollution were affected not only by the quality of irrigation water,but also by the irrigation times,agricultural fertilization,transportation,industrial and mining enterprises,daily life and production activities were closely related.