Investigation of microbial induced calcium carbonate and struvite co-precipitation on cementitious material surfaces

Microbial-induced carbonate precipitation (MICP) has garnered increasing attention in the realm of building materials. Among them, urease microorganisms have been extensively investigated due to their favorable attributes, including facile reaction control, heightened mineralization efficiency, and straightforward microorganism cultivation. Nevertheless, the presence of ammonia byproducts throughout the reaction process significantly restricted its extensive utilization. This work employed the application of microbial-induced carbonate precipitation (MICP) technology to modify the surface of cement-based materials in a solution environment. Simultaneously, the generation of struvite (MgNH 4 PO 4 •6H 2 O) was induced to eliminate ammonia byproducts and improve the cementitious ability of the film layer. The potential synergistic impact between calcium carbonate (CaCO 3 ) and struvite was observed, resulting in the production of a composite film with enhanced performance. Furthermore, the elimination efficacy of ammonia byproducts was found to exceed 90% after a treatment duration of 96 h.