Ureolytic Nocardia tenerifensis-driven carbonate precipitation for enhanced La3+ adsorption and immobilization

• Published in: Journal of cleaner production 2024-12, Vol.482, p.144193, Article 144193
• Main Authors: Wang, Lili, Yao, Jiaqi, Liu, Xiuming, Liu, Jinjuan, Ma, Zhouai, Chen, Xinyu, Cao, Chengliang, Li, Rongpeng, Jiang, Jihong
• Format: Article
• Language: English
• Subjects: Bioimmobilization; Calkinsite; Lanthanum recovery; MICP; Nocardia
• ISSN: 0959-6526
• DOI: 10.1016/j.jclepro.2024.144193

Rare earth elements (REEs) are essential in numerous modern industries, yet their extraction presents significant environmental challenges. Sustainable recycling technologies for REEs are therefore crucial for both environment protection and resource conservation. Microbially induced calcite precipitation (MICP) offers a promising solution. This study focused on a high urease activity (216.5 U/mL), lanthanum-tolerant (400 mg/L) strain, Nocardia tenerifensis KLBMP 9777. Ca2+ addition during the MICP process significantly alleviated the La3+ toxicity and enhanced mineralization. The maximum removal rate of La3+ increased from 66.2% to 89.1%, while the urease activity also increased from 80.7 U/mL to 101.7 U/mL. Scanning electron microscope (SEM) and X-ray energy dispersive spectroscopy (EDS) revealed the formation of needle-like and rhombic crystal structures after mineralization. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) identified carboxyl, amino, carbonyl, and carbonate groups as key players in the MICP-mediated La3+ adsorption. Further analysis by X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Thermogravimetry-derivative thermogravimetry analyses (TG/DTG) confirmed that the mineral deposits on the cell surface were calkinsite (La2(CO3)3·4H2O) and calcite (CaCO3). The findings advance our understanding of the MICP mechanism and provide a theoretical foundation for its application in REEs recovery and environmental remediation. [Display omitted] •Nocardia tenerifensis with high urease activity shows significant tolerance to La3+.•Ca2+ addition alleviates the toxic effects of high La3+ concentrations on the strain.•N. tenerifensis simultaneously induce the mineralization of calkinsite and calcite.•Filamentous prokaryotic Nocardia demonstrate promise for REEs recovery through MICP.