铅锌矿区冶炼地块土壤渗透性对重金属垂向分布的影响  

Soil permeability on vertical distribution of heavy metals in lead/zinc smelting site

作　　者：梁学超 郭朝晖 黄驰岳 高梓伦 杨锦波 LIANG Xuechao;GUO Zhaohui;HUANG Chiyue;GAO Zilun;YANG Jinbo(School of Metallurgy and Environment,Central South University,Changsha 410083,China)

机构地区：[1]中南大学冶金与环境学院,湖南长沙410083

出　　处：《中南大学学报(自然科学版)》2025年第1期44-54,共11页Journal of Central South University:Science and Technology

基　　金：国家重点研发计划项目(2018YFC1800400)。

摘　　要：冶炼地块土壤重金属污染突出,土壤渗透性对重金属的下渗迁移影响明显。本文以某铅锌冶炼地块为研究对象,研究土壤渗透性对重金属垂向分布特征及其下渗迁移的影响。研究结果表明:土壤渗透性显著影响冶炼地块剖面土壤中As、Cd、Pb的垂向迁移;地块土壤中As、Cd、Pb主要集中在[0,2) m深土层内。[0,0.5) m深内土层中As和Pb的平均质量分数分别为GB 36600-2018筛选值的1.6倍和3.5倍;土壤中As和Pb垂向迁移主要发生在渗透系数为1×10^(-4)~1×10^(-2) cm/s的中等透性土壤中,而Cd在渗透系数小于1×10^(-5) cm/s的微透水性土壤中仍会发生垂向迁移;土壤中重金属下渗迁移能力与其赋存形态明显相关,土壤中可交换态和碳酸盐结合态Cd的质量分数为25.01%,而Pb、As质量分数分别仅为12.54%和2.54%,这与相同渗透性土壤中Cd的迁移能力明显大于As和Pb的迁移能力相一致,因此,中、弱透水性和微透水性土壤中Cd的垂向迁移是其地块污染防控的关键。Soil permeability on the vertical distribution of As,Cd and Pb and their infiltration and migration in a lead and zinc smelting site was studied.The results show that the soil permeability severely affects the vertical migration of As,Cd and Pb in site soils.As,Cd and Pb in the profiled soil of the smelting site are mainly concentrated in the depth range of 0-2 m,The average mass fractions of As and Pb in the depth of[0,0.5)m soil layer are 1.6 and 3.5 times of the GB36600-2018 screening values,respectively.The vertical migration of As and Pb occurs mainly in moderately permeable soils with infiltration coefficients of 1×10^(-4) cm/s to 1×10^(-2) cm/s.In contrast,Cd still migrates vertically in minimally permeable soils with permeability coefficients less than 1×10^(-5) cm/s.The migration capacity of heavy metals in soils is clearly correlated with their forms of deposition.The migration capacity of heavy metals in soils by infiltration is significantly correlated with their hosting patterns.The mass fraction of Cd in the exchangeable and carbonate-bound forms of the soil is 25.01%,while Pb and As are only 12.54% and 2.54%,respectively.This is consistent with the fact that the migration capacity of Cd is significantly greater than that of As and Pb in soils of the same permeability.Therefore,the improvement of soil impermeability barrier measures can effectively control the risk of infiltration and migration of heavy metals,especially Cd,in the lead and zinc smelting site soil.

关 键 词：铅锌冶炼地块 土壤渗透性 重金属 下渗迁移 

分 类 号：X53[环境科学与工程—环境工程]