Biominerlisation as a Remediation Technique: A Critical Review

Rapid industrialization and urbanization cause release of significant quantities of hazardous contaminants, including heavy metals and radionuclides, into the biosphere. Severe accumulation of these contaminants and their exposure deteriorates human health, environment, and biota system. Conventional remediation of heavy metal, radionuclide contaminated soils includes physicochemical extraction, stabilization/solidification/immobilization, soil washing. These techniques demand large quantities of chemical reagents, huge cost apart from the generation of secondary toxic by-products, and hence, the aforementioned techniques become unsuccessful and ineffective. This necessitates an interdisciplinary approach using biomediated processes and/or derived by-products, which enhances remediation process through accelerated biogeochemical phenomenon. Bioremediation is a broad area which involves large matrix of remediation techniques such as bioaccumulation, biosorption, biosparging, bioleaching, biomineralization, phytoremediation. Among all these techniques, biomineralization or microbially induced carbonate mineral precipitation is the most fascinating, promising methods to handle the present-day challenges pertaining to remediation of contaminated soils. In view of this, the current study presents a critical review on mechanisms of microbially induced carbonate precipitation in view of solid-phase sequestration of inorganic contaminants. Further, this study assesses the suitability of various microorganisms along with the associated precipitation processes for transforming soluble inorganic compounds into stable and non-redox sensitive carbonate minerals.