Recovery of binary-component textile wastewater contaminated by reactive dyes through adsorption onto magnetic separable MgO nanoparticles produced from solid waste of ductile cast iron industry, process identifications, characterization and regeneration

Abstract

A new magnetic separable Mg-based adsorbent was produced from a waste collected from cast ductile iron industry for removing reactive dyes from the industrial textile wastewater. The magnetic coreshells were prepared based on one step gel-combustion approach. Mg2+ ions were extracted from the gray solid waste through the acid leaching. The coreshells were added to the prepared solution under sonication, and then Mg(OH)2 particles were decorated onto magnetic nanoparticles via precipitation followed with calcination at 500 °C. The reusable adsorbent was utilized for the uptake of R Blue 222, and R Red 195 dyes from single, and binary-component effluents. The adsorption studies were conducted at a variety of dye concentrations by adding different dosage of adsorbents. The competitive adsorption studies demonstrated that the capacity for the dye uptake from the binary-component wastewaters is greater than those for single-component systems, promoting the adsorptive performance. With decoration of MgO nanoparticles over the coreshells, the growth of crystallites was limited as identified from XRD patterns. An increase in pore volume, and average pore diameter, ∼ 14 nm, are the main reasons for the promotion of active site numbers which is beneficial to prevent the efficient loss in capacity due to magnetization.