Jackfruit leaf-derived activated carbon for Cr(III) sorption from synthetic and industrial tannery wastewater

This study explores the development of activated carbon from jackfruit leaf powder (JLPAC) using KOH as an activating agent for Cr(III) removal from synthetic and real tannery wastewater. The surface morphology, elemental composition, functional groups, porosity, and surface charge of the adsorbent were characterized using SEM, EDX, FTIR, nitrogen adsorption–desorption analysis, and pHpzc measurement. The influence of key parameters—including pH, adsorbent dosage, concentration, contact time, and temperature—was investigated to optimize Cr(III) adsorption. Batch equilibrium adsorption experiments demonstrated a strong fit to the Langmuir isotherm, with JLPAC achieving maximum Cr(III) uptake of 285.7 mg/g in synthetic wastewater and 105.26 mg/g in real tannery effluent. Thermodynamic analysis confirmed the adsorption process to be spontaneous, feasible, and endothermic. Desorption experiments demonstrated the recyclability of the adsorbent, with Cr(III) effectively eluted using 0.5 M H₂SO₄. Additionally, a continuous column experiment was conducted to assess the performance of JLPAC in treating real tannery wastewater containing an initial Cr(III) concentration of 3280 mg/L, where the adsorbent achieved an adsorption capacity of 78.74 mg/g. These findings reveal the potential of JLPAC as an effective and sustainable adsorbent for industrial wastewater treatment.