Biogenic material design by stone waste treatment with biologically induced mineralization

One of the most widely studied branches of biologically induced mineralization (BIM) processes, microbially induced calcium carbonate precipitation, also known as microbially induced calcite precipitation, can be used as a method for the reinterpretation of waste natural stone particles into a sustainable material. By overcoming the need for synthetic adhesives or energy-consuming firing or sintering procedures for regaining such wastes, a natural and sustainable solution is proposed through certain biological treatment processes. The aim of this study was to determine the main processing variables affecting microbially induced biocement production using waste stone as a scaffold material. Bacillus pasteurii bacteria were used for biological induction of calcite precipitation. A custom-made reactor was designed for controlled incubation and medium injection into the waste stone scaffold. The parameters examined were the particle size of the waste stones, the effect of the stone type on cementation, the urease activity of the bacterial culture, temperature, the pH and flow rate of media, the mechanical strength of cemented scaffolds and water absorption capacity. This research demonstrated a potential solution to the waste generation problem of the global natural stone industry through the treatment of such wastes with BIM for creating a sustainable and biogenic material.