Microbial-induced carbon dioxide (CO2) mineralization: Investigating the bio-mineralization chemistry process and the potential of storage in sandstone reservoir

Abstract

Mineralization represents a crucial technological approach for carbon sequestration. In this study, a strain ZL-03 with carbon mineralization ability was screened and identified as Bacillus mucilaginosus Krassilnikov by 16SrDNA. The growth morphology, physicochemical properties, and metabolic products of the strain under CO₂ stress were comprehensively investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Furthermore, employing the highly precise ¹³CO₂ isotope, the chemical pathway of microbial extracellular induction for CO₂ sequestration and biomineralization was elucidated. The results indicate that strain ZL-03 exhibits increased carbonic anhydrase (CA) activity and secretes extracellular organic matrix containing electron-donating functional groups such as -OH and -COOH under CO₂ stress. The study reveals two pathways for strain ZL-03's extracellular mineralization of CO₂:the secretion of CA promotes the dissolution and ionization of CO₂ into HCO₃⁻, which then combines with Ca²⁺ to form minerals; the microbial secretion of extracellular organic matrix complexes with Ca²⁺ in the solution to form a mineralization matrix, and CO₂ reacts with the mineralization matrix (metal complex) to generate amorphous calcium carbonate (CaCO₃·H₂O). Moreover, the research results reveal that the selected microorganisms can reduce reservoir permeability by 63.8%.

The findings provide valuable insights into the growth behavior, physicochemical characteristics, and intricate metabolic pathways of the bacterial under CO₂ stress conditions. The research significantly contributes to the understanding and advancement of microbial-mediated biomineralization processes for efficient CO₂ mineralization, with implications for environmental sustainability and carbon utilization strategies.