Affordable and reliable cationic-anionic magnetic adsorbent: Processing, characterization, and heavy metals removal

Abstract

In this work, new and superb magnetic adsorbent has been tailored via one-step dry-coating process. The developed magnetic adsorbent was fabricated from Antigorite, Bentonite, and Iron oxide for the first time, showing excellent capability for adsorption of positively and negatively charged contaminants. The structural and surface characteristics of the adsorbent were analyzed by X-ray fluorescence, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared, scanning electron microscopy-energy dispersive X-ray spectrometer, and Brunauer–Emmett–Teller analysis techniques. Zeta potential and particle size were sufficiently studied. Adsorption parameters for removal of both cations (Cd2+, Pb2+) and anions (AsO43− and CN−) were investigated. The maximum adsorption capacities were about 219.2 mg/g for Cd2+, 201.2 mg/g for Pb2+, 182.6 mg/g for AsO43−, and 157.7 mg/g for CN−. Freundlich isotherm was the best model to describe the chemisorption behavior of the studied heavy metals. The composite exhibited high regeneration efficiencies of about 92.8% and 91.3% for removal of Cd2+ and AsO43−, respectively after six reuse cycles. The composite could be efficiently implemented, easily separated and successfully recycled exhibiting 90% removal efficiency after treatment of real electroplating wastewater.