Uranium removal from complex mining waters by alginate beads doped with cells of Stenotrophomonas sp. Br8: Novel perspectives for metal bioremediation

• DOI: 10.1016/j.jenvman.2021.113411
• Publication Date: 2021-07-28T12:00:21Z
• Authors: Iván Sánchez-Castro; Pablo Martínez-Ro...; María M. Abad; Michael Descostes; Mohamed Larbi Mer...
• Keywords: Stenotrophomonas

Uranium-containing effluents generated by nuclear energy industry must be efficiently remediated before release to the environment. Currently, numerous microbial-based strategies are being developed for this purpose. In particular, bacterial strain Stenotrophomonas sp. Br8, isolated from U mill tailings porewaters, has been already shown precipitate U(VI) as stable phosphates mediated phosphatase activity. However, upscaling of strategy should overcome some constraints regarding cell exposure harsh environmental conditions. present study, immobilization Br8 biomass in an inorganic matrix was optimized provide protection cells well make process more convenient real-scale utilization. The use biocompatible, highly porous alginate beads resulted best alternative when investigating a multidisciplinary approach (High-Angle Annular Dark-Field Scanning Transmission Electron Microscopy (HAADF-STEM), Environmental (ESEM), Fourier Transform Infrared Spectroscopy with Attenuated Total Reflectance, etc.) several consolidated entrapment methods. This biomaterial applied complex real mining porewaters (containing 47 mg/L U) presence organic phosphate source (glycerol-2-phosphate) produce reactive free orthophosphates through Uranium rates around 98 % were observed after one cycle 72 h. terms removal ability function biomass, Br8-doped determined remove up 1199.5 mg U/g dry over two treatment cycles. Additionally, conditions storing and correct application assessed. Results accumulation kinetics HAADF-STEM/ESEM analyses revealed that immobilized is biphasic combining first passive sorption onto bead and/or surfaces second slow active biomineralization. work provides new practical insights into biological physico-chemical parameters governing high-efficient bioremediation based on activity waters under laboratory