文献类型：期刊文献

英文题名：Influence of pH on the leaching behavior of a solidified arsenic contaminated soil

作者：Zhang, Wenjie Yu, Haisheng Huang, Jinxiang Jiao, Weiguo

第一作者：Zhang, Wenjie

通信作者：Jiao, WG[1]|[14440115d1579e19849a1]焦卫国;

机构：[1]Taizhou Univ, Coll Civil & Architectural Engn, Taizhou, Peoples R China;[2]Shanghai Construct Grp Co Ltd, Shanghai, Peoples R China;[3]Shanghai Univ, Sch Mech & Engn Sci, Shanghai, Peoples R China;[4]Guizhou Inst Technol, Dept Civil Engn, Guiyang 550003, Peoples R China

第一机构：Taizhou Univ, Coll Civil & Architectural Engn, Taizhou, Peoples R China

通信机构：corresponding author), Guizhou Inst Technol, Dept Civil Engn, Guiyang 550003, Peoples R China.|贵州理工学院;

年份：2023

外文期刊名：ENVIRONMENTAL TECHNOLOGY

收录：;EI(收录号：20233214500899);Scopus(收录号：2-s2.0-85166768493);WOS:【SCI-EXPANDED(收录号:WOS:001040778800001)】；

基金：This work was supported by National Natural Science Foundation of China (Grant Nos. 52069005, 52268053 and 41772300).

语种：英文

外文关键词：Arsenic; pH; semi-dynamic leaching test; stabilization; solidification; potential mobile risk; >

摘要：Stabilization/solidification is widely used for treatment of arsenic (As)-contaminated soils. The stability of the soil may deteriorate significantly when exposed to acid or alkaline leachate. In this study, semi-dynamic leaching tests under different pH were carried out to investigate the leaching behavior of As from the solidified soils. Spectroscopic and microscopic analyses were performed to reveal the related mechanisms. The results showed that the leaching of As was closely correlated with the pH of the leachate, because the encapsulation effect of the cementitious matrix and the chemical speciation and valence of As were all significantly influenced by pH. In the strongly acidic leachant (pH 3.0), the leached As concentration increased by an order of magnitude, and the effective diffusion coefficient of As reached 3.71 x 10(-13) m(2)/s. This is because that pores and cracks increased owing to the acidic corrosion of CSH, such that the physical encapsulation effect was reduced and the mobility of As increased. The leachability index showed that the solidified soil was unsuitable for 'controlled utilization' under strongly acidic conditions. The leached As concentration was the lowest in the weakly alkaline leachant (pH 9.0) because under weakly alkaline conditions the hydration process of the cement was facilitated, and more CSH gels were attached to the surface of the soil particles, forming a tighter structure for As encapsulation. However, as pH increased from 9.0-11.0 the leached As concentration increased due to an increased content of As(III)-O in the solidified soil.