Comparative Adsorption of Precious and Non-Precious Metals From Real Refinery Wastewater Using Coal and Coconut Based Activated Carbons

This study investigates the recovery of precious metals from wastewater generated by a precious metal refining plant using adsorption techniques with coal-based activated carbon (Coal-AC) and coconut-based activated carbon (Coconut-AC).The research focuses on the recovery of precious metals at varying pH levels and different dosages of activated carbon.Additionally, since non-precious metals (non-PMs) are also present in the wastewater, their removal was examined under the optimal conditions identified.The Coal-AC and Coconut-AC used in this study were characterized using SEM-EDX, FTIR, and BET analyses.Coconut-AC exhibited a higher carbon content but a lower oxygen content compared to Coal-AC.The highest adsorption of precious metals was observed at pH 3 for Coal-AC and pH 1 for Coconut-AC.Both adsorbents achieved maximum adsorption capacity at an activated carbon dosage of 6 g/L.Notably, Coal-AC demonstrated superior adsorption performance for precious metals compared to Coconut-AC.The determined adsorption capacities for silver (Ag), gold (Au), palladium (Pd), and platinum (Pt) using Coal-AC were 1.262 mg/g, 0.558 mg/g, 0.847 mg/g, and 1.235 mg/g, respectively.Consequently, the recovery of precious metals from effluent generated by precious metal refining plants through activated carbon through adsorption can be considered a viable alternative method.