摘要
微生物矿化技术作为一个新兴研究课题,近些年来得到了广泛关注,然而因其反应机制复杂,很难从时间和空间尺度对矿化反应过程进行定量表示。在微生物诱导碳酸盐沉淀原理的基础上,考虑细菌的吸附和筛滤效应,以及尿素水解动力学和沉淀动力学模型,对微生物矿化反应动力学理论进行了探究,并结合孔隙尺度下的微生物矿化反应试验,采用有限元软件进行多物理场耦合模拟。结果表明,细菌吸附和筛滤行为引起了细菌分布的差异性,而这种差异性进而影响了碳酸钙的沉积分布;溶液汇合初始段碳酸钙生成量横向分布不均匀,纵向分布呈增长趋势;经历40h的反应时间,渗透率可降低80%左右;当钙离子含量丰富时,碳酸钙沉淀速率受限于尿素水解速率;附着细菌量和沉淀速率的叠加效应表现为细菌被沉淀包裹的衰亡速率。本模型验证了微生物矿化沉积反应过程,丰富了微生物矿化反应理论,并有望为现场工程应用的效果预测提供参考。
The biomineralization technology that becomes an emerging research topic has attracted wide attentions in recent years.However,it is hard to quantify the reaction process of biomineralization on temporal and spatial scales due to its complicated reactive mechanisms.Based on the principle of microbially induced carbonate precipitation,considering the adsorption and straining of bacteria,adopting the kinetic model for urea hydrolysis and precipitation,a reactive kinetic theory of biomineralization is investigated.Finally,based on the biomineralization experiments on a pore scale,a finite element software is adopted for multi-physics coupling.The results show that the adsorption and straining effects lead to the differences in distribution of bacteria,and then further influence the spatial distribution of calcium carbonate.The transverse distribution of CaCO3 content during the initial mixing stage is not uniform,while the longitudinal distribution shows an increasing trend.The permeability shows an 80%reduction after 40 hours of reaction.The rate of CaCO3 precipitation is limited by the rate of urea hydrolysis when calcium ions are abundant.The decay rate of bacteria due to CaCO3 encapsulation is the combined effect of amounts of adsorbed bacteria and precipitation rate.The model can reflect the evolution of biomineralization-induced precipitation during reaction process,further enrich the theory of biomineralization reaction.This study is expected to provide reference in predicting the effect for the field-scale geotechnical engineering.
作者
赵常
何想
胡冉
刘汉龙
谢强
王誉泽
吴焕然
肖杨
ZHAO Chang;HE Xiang;HU Ran;LIU Han-long;XIE Qiang;WANG Yu-ze;WU Huan-ran;XIAO Yang(School of Civil Engineering,Chongqing University,Chongqing 400045,China;State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China;Department of Ocean Science and Engineering,Southern University of Science and Technology,Shenzhen 518055,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2022年第6期1096-1105,I0006,共11页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金优秀青年基金项目(51922024)
国家自然科学基金面上项目(52078085)
重庆市自然科学基金杰出青年基金项目(cstc2019jcyjjqX0014)
重庆市科技局技术创新与应用发展专项项目(cstc2019jscx-msxmX0335)。
关键词
微生物矿化
生化反应
溶质运移
细菌吸附筛滤
多物理场耦合
biomineralization
bio-chem reaction
solute transport
bacteria attachment and straining
multi-physics coupling
