基于微生物诱导碳酸钙沉积的生物覆膜防渗研究  

Study on anti-seepage with microbially induced calcium carbonate precipitation (MICP)-based bio-membrane

作　　者：练继建[1] 吴昊潼 闫玥[1] 付登锋 王明军[2] LIAN Jijian;WU Haotong;YAN Yue;FU Dengfeng;WANG Mingjun(School of Civil Engineering,Tianjin University,Tianjin 300072,China;China Institute of Water Resources and Hydropower Research,Beijing 100038,China)

机构地区：[1]天津大学建筑工程学院,天津300072 [2]中国水利水电科学研究院,北京100038

出　　处：《水利水电技术》2019年第8期128-136,共9页Water Resources and Hydropower Engineering

基　　金：国家重点研发计划(2016YFC0401905)

摘　　要：针对水利工程防渗堵漏的问题,以降低砂土生物覆膜透水率、提高砂土胶结之后的强度为目的,利用巴氏芽孢杆菌催化尿素水解对MICP(microbially induced calcium carbonate precipitation)生物覆膜效果的影响因素展开试验研究。采用控制变量法探究胶结液浓度和胶结时间对生物覆膜效果的影响,从而为生物覆膜技术的实际应用提供基础性数据和科学依据。结果表明:相同胶结时间的情况下,胶结液浓度越大,钙离子利用率越高;生物覆膜样本的最小渗透系数为2.42×10-5cm/s,防渗效果相当于粉土或黏土混合物,最大抗折强度为1.63 MPa,最大抗压强度为1.5 MPa;胶结液浓度是影响覆膜抗折强度的主要因素,相同浓度下的胶结时间越长,对应的抗折强度值越大;碳酸钙在颗粒间的孔隙中充当胶凝作用,碳酸钙含量与抗折和抗压强度呈正相关关系。研究成果对未来将生物覆膜技术应用于水工防渗材料具有参考价值。Aiming at the problem of anti-seepage and leakage-sealing of water conservancy project as well as taking lowering the permeability of sandy soil bio-membrane and enhancing the strength of sandy soil after cementation as the study objective, the relevant experiment is carried out with the factor of the impact from catalyzing urea hydrolysis with bacillus pasteurii on the effect of MICP bio-membrane;from which the impacts of the cementing-fluid concentration and the cementing time on the effect of bio-membrane are explored by means of control variate method, and then provides the basic data and scientific basis for the actual application of the technology of bio-membrane. The result shows that under the conditions of the same cementing time, the larger the concentration of cementing fluid is, the higher the utilizing rate of calcium ion is to be. The minimum permeability coefficient of the bio-membrane is 2.42×10-5cm/s, of which the anti-seepage effect is equivalent to that of the silt or clay mixture with the maximum flexural strength of 1.63 MPa and the maximum compressive strength of 1.5 MPa. The concentration of cementing-fluid is the main factor to impact the flexural strength of the bio-membrane, thus the longer the cementing time is, the larger the corresponding flexural strength is to be. Calcium carbonate acts the role of cementation within the pore among particles, while its content is positively correlated with flexural and compressive strengths. This study result has a referential value for the application of the bio-membrane technology to the hydraulic anti-seepage materials in the days to come.

关 键 词：MICP 生物覆膜 力学性能 微生物 碳酸钙 

分 类 号：TU528[建筑科学—建筑技术科学]