Efficient removal of Cr(iii) by microbially induced calcium carbonate precipitation.

Microbially induced calcium carbonate precipitation (MICP) has emerged as a promising technique for environmental remediation, particularly for heavy metal removal. This study explores the potential of MICP for Cr(iii) removal, analyzing the effects of temperature, pH, calcium source addition, and initial Cr(iii) concentration on removal efficiency. The results show that Cr(iii) can be efficiently removed with a removal rate approaching 100% under optimal conditions (25 °C, pH 7.0, 1.0 g CaCl). The presence of Cr(iii) induces the transformation of CaCO crystals from calcite to spherulitic aragonite, forming Cr-bearing carbonate compounds and hydroxides. This study provides insights into the mechanisms and optimal conditions for MICP-mediated Cr(iii) removal, highlighting its feasibility and effectiveness for large-scale environmental remediation and offering an economical and environmentally friendly solution to Cr contamination.