首页|Bacterial activity and cementation pattern in biostimulated MICP-treated sand-bentonite mixtures

Bacterial activity and cementation pattern in biostimulated MICP-treated sand-bentonite mixtures

扫码查看
原文链接
  • NETL
  • NSTL
  • 万方数据
The application of microbially induced carbonate precipitation(MICP)in clayey soils has attracted much attention,and many studies used clay as an additive to enhance microbial mineralization efficiency in sandy soils.Within the sand-clay-bacteria-calcite system,the property and content of clay play crucial roles in affecting bacterial growth and calcite formation.More important,bentonite is particularly sensitive to changes in the geochemical environment.In this study,the sand-bentonite mixtures were treated by biostimulated MICP,aiming to provide insights into the behavior of this system.The bacterial activity and cementation pattern at different bentonite contents were evaluated through a series of tests such as enrichment tests,unconfined compressive strength(UCS)tests,cementation content measure-ments,mercury intrusion porosimetry(MIP)tests,scanning electron microscopy(SEM)observations,and energy dispersive X-ray spectroscopy(EDS)analyses.The findings showed that the bentonite presence promoted the enrichment of indigenous ureolytic bacteria,with lower bentonite levels enhancing ure-olytic activity.Macroscopic and microscopic characterization indicated that the bentonite-coating sand structure was more conducive to the formation of large-sized calcite crystals capable of cementing soil particles compared to sand-supported and bentonite-supported structures.Additionally,excessive cal-cium ions(Ca2+)concentrations in the cementitious solution would lead to predominant calcite depo-sition on soil particle surfaces,contributing minimally to strength improvement.

Microbially induced carbonate precipitation(MICP)BiostimulationSand-clay mixturesBacterial activityCementation pattern

Yu Zhang、Xiangrui Xu、Shiqi Liu、Yijie Wang、Juan Du、Ningjun Jiang

展开 >

Institute of Geotechnical Engineering,School of Transportation,Southeast University,Nanjing,211189,China

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

Department of Civil and Environmental Engineering,The Hong Kong Polytechnic University,Hung Hom,Hong Kong,China

College of Civil Engineering and Architecture,Hainan University,Haikou,570228,China

展开 >

2024

10.1016/j.jrmge.2024.07.005

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(12)