摘要
为探究豫西典型废弃铅矿开采区周边土壤铅污染迁移转化规律及环境风险,研究共采集了38个点位土壤样品,系统分析了土壤中铅的空间分布特征及污染状况,同时开展淋溶条件下Pb在场地剖面土柱的迁移模拟试验。结果表明:研究区铅的平均质量分数为805mg/kg,超风险筛选值的点位有29个,超标率为76%;研究区铅单因子污染指数平均值约为37.0,重度污染点位占比达90%;潜在生态危害指数结果显示,研究区低风险范围频数达84%,RI值高达895.90,远超严重风险限值(RI≥600);在模拟酸雨和正常雨水的淋滤作用下,淋出液中Pb的释放均呈先急速上升再下降趋势,淋出液中Pb质量浓度最大值分别为3.34、0.13mg/L,其释放规律与Elovich模型相吻合;研究采用欧共体标准局顺序提取方案法(BCR SequentialExtracitonProcedure)对土壤中Pb形态进行提取分析,0~60cm土壤中弱酸提取态Pb均大幅上升,这与淋滤后铅与矿物、有机质和碳酸盐的结合能力降低密切相关。研究结果可为豫西地区废弃铅矿污染防控和治理提供科学依据。
To investigate the migration and transformation patterns of lead pollution in soils surrounding typical abandoned lead mining areas in western Henan,as well as the associated environmental risks,a total of 38 soil samples were collected.The spatial distribution characteristics and pollution status of lead in the soil were systematically analyzed,and the migration simulation experiment of Pb in the soil colum of the site profile under leaching conditions was carried out.The results showed that the average mass fraction of lead in the study area was 805 mg/kg,and there were 29 points exceeding the risk screening value,with an exceedance rate of 76%.The average single-factor pollution index for lead was 37.0,with 90% of sites classified as severely polluted.The potential ecological hazard index results indicated that low-risk occurrences reached 84% across the study area,and the RI value was as high as 895.90,significantly exceeding the severe risk threshold(RI≥600).Under leaching by simulated acid rain and regular rainwater,Pb mass concentrations in the leachate initially increased rapidly and then declined.The maximum Pb mass concentrations in the leachate were 3.34 mg/L and 0.13 mg/L,respectively,fitting well with the Elovich model.The BCR sequential extraction procedure was employed to analyze the chemical forms of Pb in the soil.The weakly acidic Pb fractions in the 0~60 cm soil layer increased significantly,likely due to reduced binding capacity of Pb with minerals,organic matter,and carbonates after leaching.These findings prvovide a scientific basis for pollution prevention and control in abandoned lead mining areas of western Henan.
作者
韩亚
程旭
张晨
马兴瑾
程浩祖
HAN Ya;CHENG Xu;ZHANG Chen;MA Xingjin;CHENG Haozu(Henan Institute of Geological Sciences Co.Ltd.,Zhengzhou 450016,China;School of Environmental and Municipal Engineering,North China University of Water Resources and Electric Power,Zhengzhou 450046,China)
出处
《河南科学》
2025年第5期734-741,共8页
Henan Science
基金
河南省科技攻关计划项目(222103810014)
河南省地质科学研究所有限公司科技项目(JTZCKY2023016)。
关键词
废弃铅矿
铅污染
淋溶
迁移模拟
abandoned lead ore
lead pollution
leaching
migration simulation
