摘要
在研究区域采集45个表层土壤样品,对其含有的镉、铅、铬、铜、锌和镍6种重金属进行了全量测定和3种形态(可交换态、碳酸盐结合态、铁锰氧化物结合态)分布、组成特点分析,运用相关性分析法对各形态与全量、土壤化学指标的关系进行探讨。采用单因子污染指数法和内梅罗污染综合指数法对土壤中重金属污染进行综合评价。依据《土壤环境质量农用地土壤污染风险管控标准(试行)》表1农用地土壤污染风险筛选值判定,45个土壤样品中铅和镉的单因子污染指数较高,质量分数超标率均为6.67%,最大超标值分别是风险筛选值的2.03倍、1.58倍。6种重金属内梅罗综合污染指数为1.26,土壤呈现轻度污染水平。镉的3种形态质量占全量比例最大,为39.58%,锌、铅、铜、镍、铬的3种形态质量占比均低于21.51%。统计分析结果显示,镉和锌各形态与全量、有机质、阳离子交换量的相关程度较高,呈显著相关关系;6种重金属3个形态与土壤p H值呈负相关关系。交换态镉质量分数较高,具有较高的潜在生态风险,应加强监测。
A total of 45 soil samples were collected from the farmland of research area. Six kinds of heavy metals(Cd, Pb, Cr, Cu, Zn, Ni) were chosen to be analyzed in order to obtain the amount and the spatial distributions of their three states including exchange state, carbonate combination state and iron-manganese oxide state. Based on correlation analysis, the correlation between all forms of six heavy metals and their total content, soil properties such as pH, organic matter and CEC was discussed. A comprehensive evaluation for the heavy metal pollution in soil was made by the single factor pollution index and Nemero integrated pollution index. Some main conclusions were drawn as follows: According to the risk screening values in table 1 from the standard named Soil environmental quality Risk control standard for soil contamination of agricultural land, Pb and Cd had higher single pollution index and both the standard exceeding ratios of 6.67%. The highest contents of Pb and Cd in soil were 2.03 and 1.58 times higher that of the risk screening values. The comprehensive pollution index of Cd, Pb, Cr, Cu, Zn, and Ni in the soil was 1.26, and the soil was mild pollution;the exchange state, carbonate combination state and iron-manganese oxide state of Cd(39.58%) were the largest proportion in the concentration of total heavy metal. Whereas the proportions of Zn, Pb, Cu, Ni and Cr were lower than 21.51%;The results of statistical analysis indicated that various states of Cd and Zn had obvious correlation with the total content of heavy metal, organic matter and CEC, and three states of those six heavy metals showed negative correlation with soil p H. The exchange state of Cd had higher mass fraction, showing a potential risk of ecological pollution. So the monitoring of Cd should be strengthened.
作者
孙秀敏
陈琼
张键
张洋瑜
方植彬
SUN Xiu-min;CHEN Qiong;ZHANG Jian;ZHANG Yang-yu;FANG Zhi-bin(The 5th Electronics Research Institute of the Ministry of Industry and Information Technology,CEPREI Environmental Assessment and Monitoring Center,Guangzhou 510610,China)
出处
《当代化工》
CAS
2021年第2期293-297,共5页
Contemporary Chemical Industry
基金
广东省科技计划项目(项目编号:2016A040403039)。
关键词
农田土壤
重金属
特征分析
潜在生态风险分析
Agricultural soil
Heavy metals
Feature analysis
Assessment of potential ecological risk
