JOURNAL OF WATER PROCESS ENGINEERING, cilt.48, 2022 (SCI-Expanded)
Alunite (KAl3(SO4)(2)(OH)(6)) was evaluated for Pb2+ removal after magnetically functionalization (MagA) which led to a considerable improvement in the natural mineral's characteristics and adsorption capability. Pb2+ adsorption was investigated in both batch and column systems concerning the influence of pH, MagA amounts, contact time, initial Pb(2+ )concentration, ionic strength, flow rate, and bed height. The maximum Pb2+ adsorption performance was obtained at pH 5.0. The pseudo-second-order kinetic and Langmuir isotherm models were found to characterize the adsorption process. MagA had a monolayer Pb2+ adsorption capacity of 158.73 mg g(-1). Application tests with real wastewater have shown that MagA has satisfactory adsorption performance (> 90%) for practical applications as well. Furthermore, the adsorption efficiency of Pb2+ ions in dynamic flow mode was still around 80% after 10 consecutive cycles. MagA was characterized by infrared (IR), Brunauer-Emmett-Teller (BET), scanning electron microscope (SEM), energy dispersive X-ray (EDX), isoelectric point (IEP), and vibrating sample magnetometer (VSM) analysis. Thermodynamic analysis indicated that the binding of Pb2+ ions to MagA was endothermic. The maximum breakthrough capacity calculated from the breakthrough curve at the exhausted point was 31.1 mg g(-1). The estimated cost of preparing MagA was calculated to be 6.70 USD/kg. Overall, the findings clearly showed that the MagA seems to be an eco-friendly, economic, and recyclable adsorbent for the removal of toxic Pb2+ from wastewaters.