温度梯度作用下非饱和黏土中热湿运移及重金属离子时空分布

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国家科技期刊平台
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中文摘要：以某重金属污染场地粉质黏土为研究对象,采用自主研制的一维非饱和土热-水-化耦合试验系统开展温度梯度作用下非饱和黏土中热湿运移及重金属离子迁移试验.试验结果表明:试样两端施加一定温度差后,土体中水分由高温侧向低温侧运移,土体内部水分场重新分布.土样的初始含水率对土体水分场分布的影响最为显著,当初始含水率为12％时,离子运移效果显著,土体高温侧含水率降低了 79.3％,低温侧升高了 40.5％.同时,随着土样两端温度梯度的增大或土样干密度的降低,水分运移效果越显著.在温度梯度作用下,非饱和黏土中重金属离子随液态水一同迁移,其中,高温端重金属离子浓度减少量为28.4％～54.7％,低温端浓度增加量为19.5％～37.6％.此外,重金属离子的迁移效果也与离子种类和离子初始浓度相关.

外文标题：Heat and moisture transport and spatiotemporal distribution of heavy metal ions in unsaturated clay under temperature gradient

外文摘要：Silty clay layer from a typical heavy metal contaminated site was selected,and a self-developed one-dimensional unsaturated thermal-hydro-chemical coupled test system was employed to investigate heat and moisture transport and migration behaviors of heavy metal ions in unsaturated silty clay under a temperature gradient.Experimental results demonstrated that moisture inside the soil migrated from the high-temperature side to the low temperature one after an application of temperature gradient,leading to a redistribution of the moisture field.The water field distribution inside soil was significantly influenced by initial water content,and the migration of heavy metal ions was remarkable at the initial water content of 12％,accompanied with a 79.3％decrease of water content at the high-temperature side and a 40.5％decrease at the low-temperature side.Simultaneously,the transport of water became more and more obviously with the increases of the temperature gradient or the soil dry density.Heavy metal ions migrated together with liquid water under the action of temperature gradient,corresponding to a 28.4％～54.7％decrease in heavy metal concentration at the high-temperature side and a 19.5％～37.6％increase at the low-temperature side.Besides,the migration of heavy metals was also related to the ion type and the initial concentration.

外文关键词：

unsaturated clayheavy metal contaminationtemperature gradientheavy metal ionsheat and moisture transport

作者：

贺勇、李旺强、邹艳红、娄伟、张召、张可能

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作者单位：

中南大学有色金属成矿预测与地质环境监测教育部重点实验室,长沙 410083

中南大学地球科学与信息物理学院,长沙,410083

湖南省和清环境科技有限公司,长沙,410221

关键词：

非饱和黏土重金属污染温度梯度重金属离子热湿运移

基金：

国家重点研发计划资助项目国家自然科学基金资助项目国家自然科学基金资助项目国家自然科学基金资助项目中南大学创新驱动计划资助项目

项目编号：

2019YFC18059054237233342072318418072532023CXQD044

出版年：

2024

DOI：

10.12030/j.cjee.202311048

环境工程学报

中国科学院生态环境研究中心

环境工程学报

CSTPCD北大核心

影响因子：0.804

ISSN：1673-9108

年,卷(期)：2024.18(8)