高校地质学报2025，Vol.31Issue(6)：746-755,10.DOI:10.16108/j.issn1006-7493.2025001
次生团聚体尺寸对下蜀土铅迁移特征的影响研究
Effect of Secondary Aggregate Size on Lead Migration in Xiashu Soil
摘要
Abstract
With the acceleration of industrialization,the problem of heavy metal pollution in soil is becoming increasingly serious.Soil heterogeneity,especially the difference in the size of secondary aggregates(soil clods),significantly affects the pore structure,permeability and hydrological characteristics of the soil,thereby changing the migration process of heavy metals.Recently,although some studies have focused on the effect of soil aggregates on heavy metal migration,the mechanism of the role of soil clods of different sizes in actual soil pollution control is still lacking in-depth exploration.In this paper,the Xiashu soil which is widely distributed in the middle and lower reaches of the Yangtze River was taken as the research object.The microscopic pore distribution under different soil clod sizes was analyzed by mercury intrusion injection test(MIP),and the effect of soil clod size on the migration characteristics of typical heavy metals(lead)in the region was explored by semi-dynamic leaching test and constant head saturated permeability test system.The results show that with the increase of soil clod size,the porosity and saturated permeability coefficient of the soil body decreased.The 2-4 mm soil clod had a high lead leaching concentration in the early leaching process,resulting in a large amount of migration and dissolution;the<1 mm soil clods had a relatively uniform lead migration rate due to their strong structural connectivity,and their migration was controlled by a diffusion-based mechanism;the 1-2 mm soil clods had a moderate lead leaching concentration in the early stage and a low dissolution amount in the middle and late stages,showing a relatively strong ability to inhibit lead migration and diffusion.There fore that the reasonable distribution of soil clod size plays a key role in inhibiting the migration of heavy metals.Optimizing the size of soil clods to form a suitable soil structure can effectively slow down the migration of lead,The results provide a scientific basis for the long-term control and remediation of heavy metal-contaminated soils.关键词
次生团聚体/压实土/铅/重金属迁移/渗透性Key words
secondary aggregates/compacted soil/lead/heavy metal migration/permeability分类
天文与地球科学引用本文复制引用
李湘,沈征涛..次生团聚体尺寸对下蜀土铅迁移特征的影响研究[J].高校地质学报,2025,31(6):746-755,10.基金项目
国家重点研发计划项目(2023YFC3707900) （2023YFC3707900）
中央高校基本科研业务费专项资金(2024300399) （2024300399）
国家自然科学基金面上项目(42277123 （）
42477187) （）
江苏省自然科学基金青年项目(BK20220787)联合资助 （BK20220787）
