摘要
为提升微生物诱导碳酸钙沉积一次拌合加固红黏土的强度,需要提高胶结液的浓度以增加碳酸钙的沉积量,并解决由此引发的微生物活性降低问题。非离子表面活性剂D-山梨醇能增大细胞膜的通透性使胞内的脲酶外排,提高酶的活性来增加碳酸钙的合成。选取D-山梨醇的掺量、胶结液浓度和胶菌比这3因素,确定碳酸钙沉积最大值时各掺量,在此掺量下拌合加固红黏土。结果表明:(1)在巴氏芽孢杆菌中添加D-山梨醇能提高脲酶活性;(2)响应面试验确定碳酸钙沉积最大值时各条件为D-山梨醇掺量为0.48 g/L、胶结液浓度为3.72 mol/L、胶菌比为1.03:1;(3)采用95%压实度击实加固红黏土,室内养护14 d后,纯素土、微生物组和添加D-山梨醇组无侧限抗压强度分别为979、1 675、1 931 kPa;(4)通过X射线衍射(X-ray diffraction,简称XRD)分析在巴氏芽孢杆菌中添加D-山梨醇方解石含量从14.4%增加到38.8%。
To enhance the strength of red clay reinforced by microbial-induced calcium carbonate deposition(MICP)in a single mixing process,it is necessary to increase the concentration of the cementing solution in order to enhance the amount of calcium carbonate deposited and address the resulting decrease in microbial activity.The nonionic surfactant D-sorbitol increases the permeability of cell membranes,allowing the exocytosis of intracellular urease and enhancing enzyme activity,thereby promoting calcium carbonate synthesis.The three factors of D-sorbitol dosing,cementing solution concentration,and cementing solution-to-bacteria ratio were selected to determine the optimal dosing for the maximum calcium carbonate deposition,and the red clay soil was mixed and reinforced with this optimal dosing.The results showed that(1)The addition of D-sorbitol to bacillus subtilis enhances the urease activity;(2)Response surface tests were conducted to determine the optimal conditions for the maximum calcium carbonate deposition:D-sorbitol concentration of 0.48 g/L,cementing solution concentration of 3.72 mol/L,and cementing solution-to-bacteria ratio of 1.03:1;(3)After indoor curing for 14 days,the unconfined compressive strength of the red clay soil compacted and reinforced to 95%compaction was 979,1675 kPa,and 1931 kPa for the untreated,microbial,and D-sorbitol-added groups,respectively;(4)The addition of D-sorbitol led to an increase in the calcite content in Bacillus subtilis from 14.4%to 38.8%,as determined by X-ray diffraction(XRD)analysis.
作者
段书苏
候志强
王志佳
胡俊
张友良
张建经
DUAN Shu-su;HOU Zhi-qiang;WANG Zhi-jia;HU Jun;ZHANG You-liang;ZHANG Jian-jing(Hainan University,College of Civil and Architectural Engineering,Haikou,Hainan 570228,China)
出处
《岩土力学》
北大核心
2025年第S1期238-248,共11页
Rock and Soil Mechanics
基金
海南省院士创新平台项目(No.YSPTZX202320)
海南省院士团队创新中心
海南省自然科学基金(No.522CXTD510)
关键词
微生物诱导碳酸钙沉积
红黏土
D-山梨醇
拌合法
响应面法
microbially induced calcium carbonate deposition
red clay
D-sorbitol
mixing method
response surface methodology
作者简介
第一作者:段书苏,女,1988年生,博士,硕士生导师,讲师,主要从事微生物岩土技术、大宗固废资源再利用、遥感区域自然灾害评估相关研究工作。E-mail:993040@hainanu.edu.cn;通讯作者:王志佳,男,1987年生,博士,副教授,主要从事大宗固废资源再利用相关研究工作。E-mail:993041@hainanu.edu.cn
