1. Enhanced Adsorption of Uranium (VI) from Aqueous Solutions by Hydrogen Peroxide-Modified Magnetic Biochar: Performance Evaluation and Mechanistic Study.
- Author
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Xu, Zhenzhen, Li, Hangxiang, Zhang, Yangyang, and Zu, Bo
- Subjects
COMPLEXATION reactions ,URANIUM mining ,AGRICULTURAL wastes ,CARBOXYL group ,WATER pollution ,BIOCHAR - Abstract
The improper disposal of uranium mine tailings and smelting wastewater poses significant environmental hazards, including contamination of water bodies and soil, and potential health risks to humans through the accumulation of uranium in bones and organs. This study examines the removal of hexavalent uranium (U(VI)) from water using biochar derived from agricultural waste enhanced by hydrogen peroxide (H
2 O2 ) and magnetization modifications involving the incorporation of Fe3 O4 nanoparticles onto the biochar surface. The adsorption capacities were evaluated through batch experiments, and the mechanisms were analyzed using SEM, FT-IR, XPS, and BET surface analysis. These modifications were found to significantly increase the biochar's specific surface area from 17.606 m2 /g to 195.62 m2 /g and pore volume from 0.037 cm3 /g to 0.132 cm3 /g, and surface enrichment with oxygen-containing functional groups, particularly carboxyl groups. The inherent adsorption efficiency of biochar for U(VI) is significantly enhanced by these modifications, with the adsorption capacities of H2 O2 -modified (HBC) and magnetized HBC (MBC) reaching 69.50 mg/g and 77.58 mg/g, respectively. The adsorption mechanisms of BC, HBC, and MBC for U(VI) involve complexation reactions where hydroxyl and carboxyl groups, among other oxygen-containing functional groups on the biochar, interact with uranyl ions. HBC and MBC exhibit enhanced complexation due to higher carboxyl content, leading to improved U(VI) adsorption. Additionally, the presence of iron-containing functional groups on the surface of MBC contributes to electrostatic interactions and facilitates complexation reactions between Fe-O and uranyl ions, enhancing the overall adsorption process. These findings highlight the potential of modified biochar for the removal of U(VI) from water, particularly for the treatment of mine tailings and smelting wastewater, with significant implications for industrial applications in environmental remediation. [ABSTRACT FROM AUTHOR]- Published
- 2024
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