Adsorption of copper ions from aqueous media using montmorillonite-Al2O3 nano-adsorbent incorporated with Fe3O4 for facile separation

Abstract

In the present study, the removal of copper as a common pollutant in industrial wastewaters is considered. For this purpose, montmorillonite (MMT) was doped by Al2O3 nanoparticles via precipitation technique. For immediate separation upon removal, Fe3O4 nanoparticles were incorporated into the as-prepared nanocomposite matrix. The nanocomposite synthesized via co-precipitation is characterized in terms of morphology and structure using SEM, FE-SEM, EDS and XRD analysis techniques. Also, to verify the magnetic property, value stream mapping (VSM) was performed. To achieve the highest removal rate, effect of parameters such as pH, initial pollutant concentration, amount of adsorbent, temperature and contact time were investigated using Design Expert software. According to the results, at the optimal condition (pH=8.3, pollutant concentration=36 ppm and adsorbent content=77 mg), ∼99% Cu (II) removal was obtained. Experimental data are well consistent with Langmuir adsorption isotherm which confirms single layer adsorption. To investigate the adsorbent efficiency in continuous cycles, the adsorbent was utilized in five cycles without washing, indicating an acceptable removal percentage without significant plunge.