微生物矿化沉积时空演化的微流控芯片试验研究  

Spatiotemporal evolution of microbial-induced calcium carbonate precipitation based on microfluidics

作　　者：何想 刘汉龙[1,2,3] 韩飞 马国梁 赵常 楚剑 肖杨[1,2,3] HE Xiang;LIU Han-long;HAN Fei;MA Guo-liang;ZHAO Chang;CHU Jian;XIAO Yang(School of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area,Chongqing University,Chongqing 400045,China;National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas(Chongqing),Chongqing 400045,China;University of New Hampshire,Hampshire 03824,USA;School of Civil and Environmental Engineering,Nanyang Technological University,Singapore 639798,Singapore)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045 [3]库区环境地质灾害防治国家地方联合工程研究中心(重庆),重庆400045 [4]新罕布什尔大学,美国新罕布什尔州03824 [5]南洋理工大学土木与环境工程学院,新加坡639789

出　　处：《岩土工程学报》2021年第10期1861-1869,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金重点项目(41831282);国家自然科学基金优秀青年项目(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);重庆市研究生科研创新项目(CYB18035)。

摘　　要：微生物矿化沉积是近年来的热门研究课题,然而人们对其时空演化过程的认识目前稍显不足。设计了具有大小孔隙的概念化微流控芯片,并利用微生物加固可视化系统对微生物矿化沉积的时空演化过程进行研究。提出了一种图像处理方法,该方法能够对沉积过程中的碳酸钙进行识别和计算,从而对微生物矿化沉积的时空演化过程进行量化研究。结果表明孔隙空间结构对碳酸钙晶体具有一定的调控作用,管道大孔隙中碳酸钙以单晶的形式存在,而砂颗粒间小孔隙中碳酸钙以聚合体的方式渐进生长并表现出3个不同的生长过程。无论单晶还是聚合体碳酸钙,它们的生长速率均随反应时间先增加后逐渐降低,碳酸钙晶体面积的等效半径增长速率最大为4.22μm/min。研究结果有望验证孔隙尺度微生物矿化沉积模拟,为现场工程应用提供参考。The microbial-induced calcium carbonate precipitation(MICP)is a hot research topic in recent years,however,the understanding of its spatiotemporal evolution is still insufficient.This paper aims to investigate the spatiotemporal evolution process by designing a conceptual microfluidic chip within large and small pores and using a visualized experimental platform.An image-processing method is proposed to distinguish the calcium carbonate and measure its areas during the precipitation process,which allows the quantitative study on the spatiotemporal evolution process of MICP.The results show that the pore structures are involved in regulation of crystallization of the calcium carbonate.The calcium carbonate in the large pores of the channel exhibit as a single crystal,while those in the small pores between the sand particles show asymptotic growth in the form of aggregates and exhibit three different growth processes.Regardless of single crystal or crystalline aggregates,the growth rate of the calcium carbonate first increases and then gradually decreases with the increasing reaction time.The maximum growth rate is 4.22μm/min with respect of the equivalent radius of the calcium carbonate crystals.This study is expected to benchmark the pore-scale modeling of biomineralization and provide reference for field practices.

关 键 词：微生物矿化 微流控芯片 碳酸钙 生长速率 MICP 

分 类 号：TU411[建筑科学—岩土工程]