Biochar-Montmorillonite Composites Derived from Bamboo and Corncob biomass for the Removal of 133Ba and 137Cs from the Aqueous Solution

Abstract Radioactive contamination by 133 Ba and 13 ⁷Cs poses significant environmental risks, demanding efficient remediation strategies. This study presents the synthesis and use of innovative biochar–montmorillonite composites, produced from bamboo (BMB) and corn cob (CMB) biomass, for the removal of radionuclides from water. Physicochemical characterization confirmed successful composite formation. Crucially, the composites displayed distinct and complementary adsorption selectivities: BMB preferentially adsorbed 133 Ba (qmax ≈ 0.45 mmol/g), while CMB exhibited superior performance for 13 ⁷Cs (qmax ≈ 0.40 mmol/g), outperforming BMB for this ion under the tested conditions. Optimal Ba 2 ⁺ removal occurred at pH 4, whereas Cs⁺ adsorption was effective across a wider pH range. Pseudo-second-order kinetics governed the adsorption process for both ions on both materials, indicating chemical interactions play a key role. Isotherm analyses further elucidated the adsorption mechanisms. This work highlights the potential of designing sustainable, biomass-derived composites with tailored selectivity for efficient and targeted removal of specific radionuclides, advancing environmental remediation and nuclear waste management technologies.