Recycling leather buffing dust into activated carbon for efficient turbidity removal from tannery wastewater

Leather buffing dust (BD), a solid waste generated from the leather industry, was utilized as a raw material for synthesizing activated carbon (AC) through ZnCl₂ activation and pyrolysis. The main focus of this study was to prepare an adsorbent with low price and high efficiency to remove turbidity from tannery wastewater to contribute to the waste valorization and circular economy practices. Prepared AC were characterized with FTIR, XRD and SEM tests to confirm functionality of surfaces, modification of structure and also pore morphology. To determine turbidity removal under different conditions, batch adsorption analysis was conducted. The maximum removal efficiency attained by the BD derived AC in removing turbidity was 98.39 % at pH 5, 2 g/L dosage and 25 min of contact time. Moreover, the adsorption process significantly improved water quality by lowering total dissolved solids, chemical oxygen demand and total suspended solids up to 29.53, 78.28 and 91.13 % respectively. The adsorption kinetics followed pseudo- second-order model and equilibrium data fit well with the Langmuir isotherm indicating monolayer chemisorption. The findings indicate that leather BD can be effectively repurposed into a functional adsorbent, offering both environmental and industrial benefits for tannery wastewater treatment.