Bioremediation of stainless steel pickling sludge through microbially induced carbonate precipitation. (July 2022)

• Record Type: Journal Article
• Authors: Zhang, Junke; Su, Peidong; Li, Lin
• Is Part Of: Chemosphere. Volume 298(2022)
• Publication Date: 2022-07
• Subjects: MICP -- Bio-mineralization -- Bacteria toxicity -- Hazardous material -- Chromium leaching; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.134213
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: In this study, microbial induce carbonate precipitation (MICP) was introduced to immobilize chromium (Cr) in stainless steel pickling sludge (SSPS). Two methods were utilized to conduct the MICP process — Bacteria lysis liquor (BLL)-based MICP and bacteria-based MICP. BLL was obtained by breaking the cell walls with ultrasonic treatment. The urea hydrolyzation test illustrated that the BLL was better than bacteria solution. Both the treatments of bacteria lysis liquor-based MICP and bacteria-based MICP process can effectively entrap the Cr into mineral lattices, that reduce the potential environmental risk of SSPS. With 30 g/L urea and 7 days' treatment, BLL-based MICP presented better immobilization performance than bacteria-based MICP by lowering the bacteria concentration (OD600 ) from 0.8 to 0.7. The excellent biosorption of BLL contributed to Cr removal. Nevertheless, the addition of calcium (Ca) significantly enhanced the immobilization performance of bacteria-based MICP process rather than BLL-based MICP process. pH-dependent leaching tests illustrated the leaching of Cr followed an amphoteric pattern, while the leaching of Ni and Ca followed the cation pattern. Geochemical modeling revealed that the leaching of Cr from bio-mineralized products was solubility-controlled by Cr(OH)3 and Cr2 O3 . Graphical abstract: Image 1 Highlights: Bacteria lysis liquor-based MICP presented better immobilization performances. The addition of Ca improved the immobilization of Cr in bacteria-based MICP process. Cr from bio-mineralized products showed strong pH-dependent leaching behavior. Cr presented as Cr2 O3 and Cr(OH)3 in the bio-mineralization products.