Adsorption and Enrichment of Ag(I) from Wastewater Using Wheat Bran‐Derived Biosorbent

Abstract 2,5‐Dimercapto‐1,3,4‐thiadiazole modified wheat bran (DMTD‐WB), a bio‐sorbent synthesized by immobilizing DMTD onto WB, demonstrated outstanding selectivity for Ag(I) recovery from multi‐metal wastewater. Under optimized conditions (30 °C, pH 3.0, dosage of 6.00 g L −1 ), an Ag(I) adsorption efficiency of 98.15 % was achieved. Fixed‐bed adsorption experiments further confirmed its selectivity, whereas regeneration tests indicated a recovery efficiency of 81.43 % for Ag(I) after five cycles. Thermodynamic analysis revealed a maximum adsorption capacity of 60.39 mg g −1 at 40 °C. Kinetic and mass transfer studies identified chemisorption via coordination as the dominant adsorption mechanism, with the homogeneous solid diffusion (HSD) model providing a satisfactory fit for the adsorption kinetics. Overall, this study highlights DMTD‐WB as a sustainable and efficient adsorbent for Ag(I) recovery, offering a value‐added approach to agricultural waste utilization in wastewater treatment.