Spatiotemporal variations of sand hydraulic conductivity by microbial application methods  

作　　者：Viroon Kamchoom Thiti Khattiwong Treesukon Treebupachatsakul Suraparb Keawsawasvong Anthony Kwan Leung 

机构地区：[1]Excellent Centre for Green and Sustainable Infrastructure,Department of Civil Engineering,School of Engineering,King Mongkut’s Institute of Technology Ladkrabang(KMITL),Bangkok,10520,Thailand [2]Department of Biomedical Engineering,School of Engineering,King Mongkut’s Institute of Technology Ladkrabang(KMITL),Bangkok,10520,Thailand [3]Department of Civil Engineering,Thammasat School of Engineering,Thammasat University,Prathumthani,10200,Thailand [4]Department of Civil and Environmental Engineering,The Hong Kong University of Science and Technology(HKUST),Hong Kong,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第1期268-278,共11页岩石力学与岩土工程学报（英文版）

基　　金：The first author(V.Kamchoom)acknowledges the grant(Grant No.FRB66065/0258-RE-KRIS/FF66/53)from King Mongkut’s Insti-tute of Technology Ladkrabang(KMITL)and National Science,Research and Innovation Fund(NSRF);the grant under Climate Change and Climate Variability Research in Monsoon Asia(CMON3)from the National Research Council of Thailand(NRCT)(Grant No.N10A650844);the National Natural Science Foundation of China(NSFC).

摘　　要：The spatiotemporal distributions of microbes in soil by different methods could affect the efficacy of the microbes to reduce the soil hydraulic conductivity.In this study,the specimens of bio-mediated sands were prepared using three different methods,i.e.injecting,mixing,and pouring a given microbial so-lution onto compacted sand specimens.The hydraulic conductivity was measured by constant-head tests,while any soil microstructural changes due to addition of the microbes were observed by scan-ning electron microscope(SEM)and mercury intrusion porosimetry(MIP)tests.The amount of dextran concentration produced by microbes in each type of specimen was quantified by a refractometer.Results show that dextran production increased exponentially after 5-7 d of microbial settling with the supply of culture medium.The injection and mixing methods resulted in a similar amount and uniform dis-tribution of dextran in the specimens.The pouring method,however,produced a nonuniform distri-bution,with a higher concentration near the specimen surface.As the supply of culture medium discontinued,the dextran content near the surface produced by the pouring method decreased dramatically due to high competition for nutrients with foreign colonies.Average dextran concentration was negatively and correlated with hydraulic conductivity of bio-mediated soils exponentially,due to the clogging of large soil pores by dextran.The hydraulic conductivity of the injection and mixing cases did not change significantly when the supply of culture medium was absent.

关 键 词：Bio-mediated soil DEXTRAN Hydraulic conductivity Leuconostoc mesenteroides Microbial application MICROSTRUCTURE 

分 类 号：TV223[水利工程—水工结构工程]