Controlling the Distribution of Microbially Precipitated Calcium Carbonate in Radial Flow Environments

• DOI: 10.1021/acs.est.8b06876
• Publication Date: 2019-04-22T14:54:35Z
• Authors: Neerja M. Zambare; Ellen G. Lauchnor; Robin Gerlach
• Keywords: 0106 biological sciences; Sporosarcina; Chemical Precipitation; Urea; Porosity; 01 natural sciences; 6. Clean water; Calcium Carbonate; 0105 earth and related environmental sciences

Bacterially driven reactions such as ureolysis can induce calcium carbonate precipitation, a well-studied process called microbially induced precipitation (MICP). MICP is of interest in subsurface applications sealing leaks around wells. For effective field deployment, it important to study under radial flow conditions, which are relevant near-well environments. In this study, laboratory-scale reactor 23 cm diameter, with 1 mm glass bead monolayer serving porous medium, was used investigate the effects fluid rates and concentrations on mass distribution by ureolytic bacterium Sporosarcina pasteurii. Experiments were performed at hydraulic residence times 14, 7, 3.5 min urea molar ratios 0.5:1, 1:1, 2:1. The total amount CaCO3 precipitated increased increasing time decreasing Ca2+ ratios. Increased bacterial attachment observed distance from center inlet all experiments. More uniform achieved lower rates. relationship between reaction transport rate (i.e., Damköhler number) identified useful parameter for prediction