摘要
微生物诱导碳酸盐沉积(MICP)技术是近年来发展起来的一种新型绿色加固技术,如何提升MICP技术的加固效能一直是学者关注的热点,本工作重点结合巴氏芽孢杆菌产脲酶原理和非离子表面活性剂的特点,设计采用非离子表面活性剂Triton X-100提升MICP效能的试验研究。结果表明:(1)在单因素试验结果的基础上,通过响应面试验分析确定了活性剂的最优处理条件,即掺量1.37%、处理时间5.02 h、处理温度34.28℃、菌胶比1∶2.11;(2)采用最优条件处理的巴氏芽孢杆菌对钙质砂进行加固后,钙质砂固化体碳酸钙含量和无侧限抗压强度分别提升了25.48%和22.83%;(3)非离子表面活性剂Triton X-100增大了巴氏芽孢杆菌的细胞膜通透性,一方面使得更多的胞内脲酶释放到细胞外,同时更多的尿素分子进入到细胞内,促进了尿素水解,提升了碳酸钙的生成速率;另一方面使得以细菌为核点生成的碳酸钙胶凝体的结构更为致密,在这两方面作用下,MICP效能得到有效提升。相关思路和研究结果可为MICP加固效果的提升提供新的参考和思路。
Microbially induced carbonate precipitation(MICP)technology is a new green reinforcement technology developed in recent years.How to improve the reinforcement efficiency of MICP has always been a focus of scholars’attention.This work focuses on the principle of urease produced by Sporosarcina pasteurii and the characteristics of non-ionic surfactant.The experiment of improving MICP efficiency with non-ionic surfactant Triton X-100 was designed.The results showed that:(Ⅰ)based on the results of single factor experiment,response surface experiment was designed to analyze and determine the optimal treatment conditions of the surfactant,namely,the dosage was 1.37%,the treatment time was 5.02 h,the treatment temperature was 34.28℃,and the ratio of bacteria to cementation solution was 1∶2.11;(Ⅱ)the calcium carbonate content and unconfined compressive strength of the solidified body increased by 25.48%and 22.83%respectively after the calcareous sand was reinforced by Sporosarcina pasteurii under the optimal conditions;(Ⅲ)the non-ionic surfactant Triton X-100 increases the permeability of the cell membrane of Sporosarcina pasteurii.On the one hand,more intracellular urease is released to the outside of the cell,while more urea enters the cell,which promotes the hydrolysis of urea and the formation rate of carbonate.On the other hand,the calcium carbonate gel structure generates with bacteria as the core more compact.Under the effect of these two aspects,the MICP efficiency is effectively improved.Relevant ideas and research results can provide new reference and ideas for the improvement of MICP reinforcement effect.
作者
肖瑶
邓华锋
李建林
熊雨
程雷
XIAO Yao;DENG Huafeng;LI Jianlin;XIONG Yu;CHENG Lei(Key Laboratory of Geological Hazards on Three Gorges Reservoir Area of Ministry of Education,China Three Gorges University,Yichang 443002,Hubei,China)
出处
《材料导报》
EI
CSCD
北大核心
2024年第1期205-211,共7页
Materials Reports
基金
国家自然科学基金(U22A20600
U2034203)。
关键词
微生物诱导碳酸盐沉积
脲酶
非离子表面活性剂
细胞膜通透性
响应面法
microbially induced carbonate precipitation(MICP)
urease
non-ionic surfactant
cell membrane permeability
response surface method
