Bio-precipitation of CaCO3 for soil improvement: A Review

Abstract

The bio-mineralization of calcium carbonates is an innovative and eco-friendly technique for improving soil, which has recently become increasingly popular in the field of geotechnical engineering. Different bio-cementation methods are employed for improving granular soils, including microbially-induced CaCO3 precipitation (MICP) and enzymatic-induced carbonate precipitation (EICP). These methods offer innovativeness, effectiveness and sustainability when applied in geotechnical engineering, and have been suggested as possible solutions for various different geotechnical issues. More research has been conducted into MICP compared to EICP. Nevertheless, urease sourced from plants likely offers many benefits over the use of bacteria urease in bio-cementation processes. The present study reviews the mechanisms, possible areas for implementation, related benefits and drawbacks of the bio-cementations techniques. Additionally, it will concentrate on the techniques used in the precipitation of CaCO3 involving the urease hydrolysis of urea. The study findings will enhance the comprehension of biotechnical mechanisms and ensure that geotechnical specialists are suitably informed with up-to-date knowledge on this subject.