Investigation on bio-desilication process of fly ash based on a self-screened strain of Bacillus amyloliquefaciens and its metabolites.

Bio-desilication of fly ash containing a large amount of crystalline and amorphous silicate compound by silicate bacteria had the advantages of energy-saving, environment-friendly, and controllable cost. In this study, a bacteria strain with desilication ability on fly ash was isolated from the soil and identified as Bacillus amyloliquefaciens by 16sRNA and named ZGW-12. Through the bio-leaching treatment of fly ash by ZGW-12, it was found that the concentration of Si was 306.26 mg/L and the concentration of Al was 0.5 mg/L in the pulp. The mechanism of bio-leaching using ZGW-12 was investigated by XRD, HPLC, SEM, and FTIR. The organic acid and amino acid in the bacteria culture medium and the pulp were detected, and it was found that the content of the acidic metabolites in the pulp was much larger than that of the bacteria culture medium. The ore sample particles adsorbed a large number of bacteria cells and took place obvious corrosion. The surface of the ore sample undergone hydroxylation reaction, and the diffraction peak of the silicate crystal compound was unchanged. ZGW-12 exhibits good performance in retaining aluminum and extracting silicon aspect. AVAILABILITY OF DATA AND MATERIAL (DATA TRANSPARENCY): All data were true and valid.