粉煤灰及其资源化利用过程重金属生态风险研究

作者	单位
杨航	榆林学院, 陕西省陕北矿区生态修复重点实验室, 陕西榆林 719000
李懿轩	榆林学院, 陕西省陕北矿区生态修复重点实验室, 陕西榆林 719000
李强*	榆林学院, 陕西省陕北矿区生态修复重点实验室, 陕西榆林 719000 榆林市固废资源化利用工程技术研究中心, 陕西榆林 719000
艾锋	榆林学院, 陕西省陕北矿区生态修复重点实验室, 陕西榆林 719000
田亮	榆林学院, 陕西省陕北矿区生态修复重点实验室, 陕西榆林 719000
刘姿亨	榆林学院, 陕西省陕北矿区生态修复重点实验室, 陕西榆林 719000
潘伟杰	榆林学院, 陕西省陕北矿区生态修复重点实验室, 陕西榆林 719000
陶秋霞	榆林学院, 陕西省陕北矿区生态修复重点实验室, 陕西榆林 719000

通讯作者:李强* 榆林学院, 陕西省陕北矿区生态修复重点实验室, 陕西榆林 719000;榆林市固废资源化利用工程技术研究中心, 陕西榆林 719000

摘要点击次数: 442

全文下载次数: 154

中文摘要:

粉煤灰作为燃煤发电厂的副产品,大量堆存和填埋会对环境造成严重威胁。采用BCR连续提取法探究陕北粉煤灰中Cd、Cr、Ni、Cu、Pb、Hg、Tl、As、Zn等9种重金属的形态分布特征,并综合运用单因子指数法、富集因子法、内梅罗综合污染指数法、地质累积指数法及潜在生态风险指数法评估其生态风险水平,以判断资源化利用的可行性。测试结果显示,除Tl外,粉煤灰中其余重金属元素主要以残渣态存在,迁移性较低,且其全量均低于农用地土壤风险筛选值。通过单因子指数法计算得到,Tl为轻微污染,其余重金属元素无污染。地质累积指数法分析结果表明,Hg为偏中度污染,Cu、Tl、As为轻度污染水平。潜在生态风险指数评价结果表明,粉煤灰中的有效态重金属元素属于轻微生态风险。内梅罗综合污染指数显示,粉煤灰中9种重金属的风险等级为轻度污染;若去除Tl,综合污染指数降至清洁水平。综上所述,Tl是粉煤灰资源化利用中的重点关注对象;建议结合化学提取法与生物评价法构建粉煤灰重金属生态风险评价体系,以促进粉煤灰资源化利用。

英文摘要:

Fly ash,a byproduct of coal-fired power plants,poses a significant environmental threat when stored or landfilled in large quantities.The BCR sequential extraction method was employed to investigate the speciation of nine heavy metals (Cd,Cr,Ni,Cu,Pb,Hg,Tl,As,Zn) in fly ash from Northern Shaanxi.Ecological risk levels were assessed using a combination of the single-factor pollution index,enrichment factor,Nemerow Integrated pollution index,geo-accumulation index,and potential ecological risk index methods to evaluate the feasibility of resource utilization.Results indicate that,except for Tl,the other heavy metals primarily exist in the residual fraction with low mobility,and their total concentrations are below the risk screening values for agricultural soils.The single-factor pollution index revealed that Tl is slightly polluted,while the other metals show no pollution.The geo-accumulation index indicated Hg as moderately polluted,with Cu,Tl,and As classified as mildly polluted.The potential ecological risk index showed that bioavailable heavy metals pose slight ecological risks,and the Nemerow Integrated pollution index indicated mild pollution.Excluding Tl reduced the composite pollution index to a clean level.In conclusion,Tl is the primary concern in the resource utilization of fly ash.It is recommended to establish an ecological risk assessment system for heavy metals in fly ash by integrating chemical extraction and biological evaluation methods to promote its sustainable utilization.

查看全文查看/发表评论下载PDF阅读器