攀西大梁子铅锌矿区水系沉积物重金属地球化学特征及源解析  

Geochemical Characteristics and Source Identification of Heavy Metals in the River Sediments of Daliangzi Pb-Zn Mining Area in Panxi

作　　者：朱英海 施泽明[1,2] 王新宇 张凯亮[1] 朱伯丞[1] ZHU Yinghai;SHI Zeming;WANG Xinyu;ZHANG Kailiang;ZHU Bocheng(College of Earth Sciences,Chengdu University of Technology,Chengdu,Sichuan 610059,China;Sichuan Province Key Laboratory of Nuclear Techniques in Geosciences,Chengdu,Sichuan 610059,China)

机构地区：[1]成都理工大学地球科学学院,四川成都610059 [2]地学核技术四川省重点实验室,四川成都610059

出　　处：《现代地质》2022年第3期923-932,共10页Geoscience

基　　金：国家重点研发计划“深地资源勘查开采”(2018YFC0604105);国家自然科学基金项目(41373120,41807357);环保公益性行业科研专项“西南矿区地下水重金属污染源识别与污染风险评估”(201509024);中国地质调查局项目“成都龙泉山城市森林公园多要素地质调查”(WT【2020】-033)。

摘　　要：长江上游是整个长江经济带的重要生态屏障。以长江上游攀西大梁子铅锌矿区水系沉积物为研究对象,查明了重金属元素含量的空间分布特征,分析了重金属来源,探讨了在不同pH条件下重金属的淋滤规律,并进行了生态风险评估。研究结果显示:攀西大桥河流域水系沉积物中重金属的空间分布极不均匀,其含量明显要高于长江水系沉积物中重金属的平均含量;重金属生态风险属于很强风险,Hg和Cd呈高度富集、严重污染;Pb和Zn呈中度富集、中等污染。淋滤实验结果表明Pb、Zn、Cd在酸性和中性条件下淋滤浓度先快速下降,后逐渐趋于平衡,而As在快速下降后又有缓慢升高的趋势。大桥河流域水系沉积物中As、Cd、Pb、Zn主要来源于大梁子铅锌矿的采选活动,Hg为岩石风化和土壤剥蚀来源,而Cu和Cr主要为农业和工业活动来源。综合对比发现,攀西成矿带铅锌矿周边土壤富Cd而贫Cr,此外Cd、Pb、Zn、Hg是主要潜在污染物,且生态风险程度较高。The upper Yangtze River region is an important ecological security barrier for the Yangtze River Economic Belt.The river sediments collected from Daliangzi Pb-Zn mining area,Panxi in the upper reaches of the Yangtze River were investigated in this study.The spatial distribution,source,pH-dependent leaching characteristics,and ecological risk levels of heavy metals were evaluated.The results indicated that the concentration of heavy metals in the river sediments of Daqiaohe River in Panxi,whose spatial distribution of heavy metals was inhomogeneous extremely was significantly higher than in the Yangtze River.The comprehensive potential ecological risk index(RI)of heavy metals is very strong.Hg and Cd with high enrichment were severely polluted,Pb and Zn with moderate enrichment were moderately contaminated.The leaching tests showed that the concentrations of Pb,Zn and Cd in the leachate decreased rapidly and then stabilized under acidic and neutral conditions,and As decreased rapidly and then increased slowly.The source of As,Cd,Pb and Zn in the sediments of Daqiaohe River was the mining of Daliangzi Pb-Zn mining area.The source of Hg was rock weathering and pedogenesis.The source of Cu and Cr were agricultural and industrial activities.The soils in the Pb-Zn mining area of Panxi metallogenic belt were Cd-rich and Cr-poor.Cd,Pb,Zn and Hg with high ecological risks were the main potential contaminants.

关 键 词：沉积物 重金属 风险评价 淋滤实验 来源 

分 类 号：P595[天文地球—地球化学] X142[天文地球—地质学]