Removal of Pb(ii) ions from aqueous solution using a novel composite adsorbent of Fe3o4/PVA/spent coffee grounds

A novel magnetic composite prepared from Fe3O4, poly(vinyl alcohol) and alkaline pretreated spent coffee grounds (Fe3O4/PVA/APSCGs) was utilized for the first time as an adsorbent for adsorption of Pb(II) ions after carefully characterizing it by various techniques (XRD, FTIR, SEM, EDX). The obtained results indicated that the adsorption was spontaneous, endothermic, fitting well with both Langmuir and Freundlich models, and more suitable to be described by the second-order kinetic model. The maximum adsorption capacity of Fe3O4/PVA/APSCGs for Pb(II) at optimum conditions (pH of 5, contact time of 24?h, APSCGs:Fe3O4 weight ratio of 4:1) was found to be 0.275?mmol.g(?1). Recycling study showed a good reusability of the composite with removal efficiency maintained at 78.12% after five continuous adsorption-desorption cycles.