摘要
【目的】了解焦化场地土壤中重金属的赋存形态及生物有效性。【方法】采集某退役焦化厂土壤样品,采用BCR连续提取法结合ICP-OES测定土壤中7种重金属的总量及赋存形态,利用风险评价编码法和次生相与原生相比值法对重金属的生物有效性进行评价。【结果】参比江西省土壤背景值,土壤中7种重金属均存在不同程度的富集现象,砷(As)、镉(Cd)、铬(Cr)、铜(Cu)、镍(Ni)、铅(Pb)和锌(Zn)平均含量分别是背景值的3.15、18.60、2.70、1.93、2.13、0.96和1.87倍,各重金属含量的变异程度属于中等到强变异。7种重金属的主要形态均为残渣态,As、Cd、Cr、Cu、Ni、Pb和Zn占比分别是79.25%、41.10%、87.37%、59.00%、67.92%、51.02%和61.10%,可还原态和可氧化态次之,可交换态最小。Cd的有效形态占比最高,达到58.90%,具有较大的生态风险。土壤pH、有机质(SOM)与7种重金属各形态间相关性不显著,各重金属赋存形态主要受其相对应的总量影响。风险评价编码法评价结果表明,Cd为中等风险,As、Cu、Ni、Pb、Zn为低风险,Cr为无风险。次生相与原生相比值法评价结果表明,Cd为重度污染,Pb为轻度污染,As、Cr、Cu、Ni、Zn为无污染。【结论】研究区土壤中7种重金属中Cd的生物有效性和迁移性最强,是主要风险因子,其它重金属生物有效性和生态危害程度较低。
Objective The aim was to investigate the species and bioavailability of heavy metals in the soil of a coking plant.Method Soil samples were collected from a decommissioned coking plant.A BCR sequential extraction procedure combined with ICP-OES was used to determine the total contents and different forms of seven heavy metals in the soils.The methods of risk assessment coding and ratio of secondary phase and primary phase were used to evaluate their bioavailability.Result As,Cd,Cr,Cu,Ni,Pb and Zn were enriched in different degrees in the studied soils,with average contents of 3.15,18.60,2.70,1.93,2.13,0.96,and 1.87 times of the background values in Jiangxi Province,respectively.All heavy metal contents were moderately to highly variable.Residual form was the highest form for As,Cd,Cr,Cu,Pb,Ni,and Zn,accounting for 79.25%,41.10%,87.37%,59.00%,67.92%,51.02%,and 61.10%of the total contents,respectively,followed by the reducible and oxidizable forms.The exchangeable form accounted for the lowest.The effective form of Cd accounted for the highest percentage(up to 58.90%),showing a greater ecological risk as compared to other metals.Soil pH value and content of soil organic matter(SOM)did not show significant correlations with contents of different forms of the metals,which was mainly influenced by their corresponding total contents.Results of risk evaluation using coding method showed that Cd was in moderate-risk,and As,Cu,Ni,Pb,and Zn were in low-risk,and Cr was in zero-risk.Results of risk evaluation using the ratio of secondary phase and primary phase method showed that the soils were heavily contaminated by Cd,and were slightly contaminated by Pb,and were not contaminated by As,Cr,Cu,Ni,and Zn.Conclusion Among the seven heavy metals,Cd had the highest bioavailability and mobility in the soils of the study area,and was the main risk factor,while the others had low bioavailability and low ecological hazards.
作者
韦春妙
章艳红
唐玉红
刘斌
WEI Chun-miao;ZHANG Yan-hong;TANG Yu-hong;LIU Bin(State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang 330013,China;School of Water Resources and Environmental Engineering,East China University of Technology,Nanchang 330013,China;Jiangxi Fuzheng Environmental Co.Ltd,Nanchang,330103,China)
出处
《土壤通报》
CAS
CSCD
北大核心
2024年第3期810-818,共9页
Chinese Journal of Soil Science
基金
国家自然科学基金(42107093,42062017)
南昌市水文地质与优质地下水资源开发利用重点实验室(20241C23)
江西省自然科学基金(20212BAB204002)
江西省教育厅科学技术研究项目(GJJ190382)资助
关键词
焦化厂
土壤重金属
赋存形态
土壤有机质
生物有效性
Coking plant
Soil heavy metal
Occurrence form
Soil organic matter
Bioavailability
