摘要
【目的】为研究重庆市主城区土壤中的重金属总量及其形态分布特征。【方法】采集了64个表层土壤样品,利用Tessier顺序提取法对重金属进行形态分析,并采用潜在生态风险指数法和风险评价编码法(RAC)评价其生态风险程度。【结果】研究结果表明该区重金属除Pb、Cu外,其他各重金属平均值均超过了重庆市土壤背景值;形态分析表明,除Cd外,Hg、Pb、Cr、Cu、Zn、Ni以残渣态为主,而重金属Cd的形态中铁锰氧化物结合态(22%)、残渣态(21%)、可交换态(27%)的所占比例都非常接近。相关性分析结果表明,Cd和Hg、Pb、Cr以及Cu存在强烈的正相关性,仅Ni没有与其他重金属存在明显的相关性;潜在生态危害指数法显示这7种重金属的生态风险大小排序为:Cd>Hg>Cr>Ni>Pb>Cu>Zn,综合生态危害指数RI表明研究区处于强生态风险(317.408);RAC评价结果表明研究区土壤中重金属Cd已达到高生态风险;【结论】综合以上分析可得,重庆市主城区土壤中受到严重的Cd污染以及可能存在的Hg、Cd复合污染,应经常监测表层土壤中Cd和Hg的含量和形态特征,采取相应的措施来治理和控制。
【Objective】In order to study the total amount and speciation distribution characteristics of heavy metals in the soil of the main ur-ban area of Chongqing.【Method】64 surface soil samples were collected,and Tessier sequential extraction method was used to analyze the speciation of heavy metals,and potential ecological risk index method and risk assessment coding method(RAC)were used to evaluate the degree of ecological risk.【Result】The research results showed that the average value of heavy metals in this area exceeded the soil back-ground value of Chongqing,except for Pb and Cu.The speciation analysis showed that Hg,Pb,Cr,Cu,Zn and Ni were mainly in residual state,except for Cd,while the proportions of iron manganese oxide combined state(22%),residual state(21%)and exchangeable state(27%)of heavy metal CD were very close.The results of correlation analysis showed that Cd had a strong positive correlation with Hg,Pb,Cr and Cu,while Ni had no significant correlation with other heavy metals.The potential ecological hazard index method showed that the ec-ological risk of these 7 heavy metals ranked as:Cd>Hg>Cr>Ni>Pb>Cu>Zn and Comprehensive Ecological Hazard Index RI indi-cated that the study area was at high ecological risk(317.408).RAC evaluation results indicated that the heavy metal Cd in the soil of the study area had reached a high ecological risk.【Conclusion】Based on the above analysis,it can be concluded that the soil in the main urban area of Chongqing is seriously polluted by Cd and the possible Hg and Cd compound pollution.The content and speciation characteristics of Cd and Hg in the surface soil should be monitored frequently,and the corresponding measures should be taken to manage and control.
作者
姚文文
陈文德
黄钟宣
嬴乔楚
YAO Wen-wen;CHEN Wen-de;HUANG Zhong-xuan;YING Qiao-chu(School of Tourism and Urban and Rural Planning,Chengdu University of Technology,Sichuan Chengdu 610059,China)
出处
《西南农业学报》
CSCD
北大核心
2021年第1期159-164,共6页
Southwest China Journal of Agricultural Sciences
基金
重庆都市经济圈生态地球化学评价(GITR20050101)。
关键词
重庆市
重金属
顺序萃取法
潜在生态危害指数法
风险评估编码法
Chongqing
Heavy metals
Sequential extraction method
Potential ecological hazard index method
Risk assessment coding
