Feasibility of compacted attapulgite/diatomite amended clayey soils as gas barrier materials

扫码查看

原文链接

万方数据
维普

外文摘要：Compacted clay liners are extensively used as barriers to control the upward diffusion of vapors of volatile or semi-volatile organic contaminants released from unsaturated contaminated soils at industry-contaminated sites.This study aimed to investigate the gas diffusion barrier performance of compacted clayey soils amended with three agents including attapulgite and diatomite individually,and attapulgite/diatomite mixture.The properties including water retention,volumetric shrinkage,gas diffusion,and unconfined compressive strength were evaluated through a series of laboratory tests of amended compacted clayey soils.The results demonstrate that the decrease in volume proportions of inter-aggregate pores leads to an increase in unconfined compressive strength(qu).Both hydrophilic groups and microstructures of attapulgite and diatomite result in an increase in water retention percent(Wt)of compacted clayey soil specimens after amendment regardless of the type of agent or initial water content(wo).Furthermore,the ratio of the gas diffusion coefficient(De)to the gas diffusion coefficient in the air(Da)was significantly reduced owing to a decrease in volume proportions of inter-aggregate pores,hy-drophilic group,and microstructures of attapulgite and diatomite.Scanning electron microscope ana-lyses revealed that rod-shaped attapulgite filled the inter-aggregate pores formed by clay particles,whereas the disc-shaped diatomite particles,characterized by micropores,failed to obstruct the inter-aggregate pores due to their larger particle size.Mercury intrusion porosimetry(MIP)analyses showed a reduction in pore volume in the inter-aggregate pores,leading to a reduction in the total pore volume for both the attapulgite and attapulgite/diatomite mixture amended clays,which is in accordance with the scanning electron microscope(SEM)results.The findings are pertinent to the practical appli-cation of compacted clay liners as gas barriers against the upward migration of volatile or semi-volatile organic contaminants at contaminated sites.

外文关键词：

Compacted clay linerAttapulgite/diatomite mixtureDiffusion barrierWater retention

作者：

Heng Zhuang、Wei-Yi Xia、Jia-Ming Wen、Min Wang、Ying-Zhen Li、Ning-Jun Jiang、Konstantin S.Rodygin、Yan-Jun Du

展开 >

作者单位：

Jiangsu Key Laboratory of Low Carbon and Sustainable Geotechnical Engineering,Institute of Geotechnical Engineering,Southeast University,Nanjing,211189,China

Jiangsu Province Ecology and Environment Protection Engineering Research Center of Groundwater Pollution Prevention and Control,Jiangsu Environmental Engineering Technology Co.,Ltd.,Nanjing,210036,China

Zijin(Changsha)Engineering Technology Co.,Ltd.,Changsha,410006,China

Institute of Chemistry,Saint Petersburg State University,Stary Petergof,198504,Russia

展开 >

基金：

National Natural Science Foundation of ChinaPrimary Research and Development Plan of Jiangsu ProvincePrimary Research and Development Plan of Anhui Province

项目编号：

42177133BE20228302023t07020018

出版年：

2024

DOI：

10.1016/j.jrmge.2024.01.018

岩石力学与岩土工程学报(英文版)

中国科学院武汉岩土力学所中国岩石力学与工程学会武汉大学

岩石力学与岩土工程学报(英文版)

CSTPCD

影响因子：0.404

ISSN：1674-7755

年,卷(期)：2024.16(9)