Unary and binary adsorption studies of lead and malachite green onto a nanomagnetic copper ferrite/drumstick pod biomass composite.

Abstract

Modern-day practices are the major contributors in water quality deterioration, consequently results in clean water scarcity. Herein, co-precipitation procedure was adopted to develop a nanomagnetic copper ferrite/drumstick pod biomass (CuFe2O4/DC) composite, which was characterized, and optimized to sequester malachite green (MG) and lead (Pb(II)) in unary and binary systems from aqueous environment. Mesoporous CuFe2O4/DC surface with 16.96 m2/g BET surface area and acid functionalities predominance was observed. Under the studied experimental conditions, MG adsorption on CuFe2O4/DC in unary system was comparatively higher than that of Pb(II). MG and Pb(II) equilibrium results were fitted to Langmuir isotherm model, their respective maximum monolayer adsorption capacities at 328 K being 952.4 and 921.1 mg/g. On the other hand, binary system (in presence of MG) fastened Pb(II) adsorption kinetics and increased its uptake capacity. Additionally, humic acid (HA) matrix enhanced Pb(II) adsorption kinetics. Recovery studies showed maximal MG and Pb(II) elution with C2H5OH and 0.1 mol/L HCl, respectively. An 82.7% drop in Pb(II) adsorption was found after the first regeneration cycle, while only 17.6% fall in MG adsorption was witnessed after five consecutive regeneration cycles. Hence, it could be concluded that CuFe2O4/DC is a cost-effective and promising adsorbent for an efficient and rapid removal of Pb(II) and MG from both unary and binary systems.