Feasibility Study of Cd(II) Adsorption by a Novel Magnetic-Graphene Oxide Assisted with Polymer from Solution

Abstract

The harmful effects of cadmium (Cd) to human health associated to its structure and chemical form. Cd(II) pollution is classified as causing economic and environmental damages due to being a probable human carcinogen and its severe effects to ecosystems. This work asserted a facile synthesis and easy-to-collect adsorbent to remove Cd(II). The magnetic-graphene oxide-based nanocomposite was synthesized via a two-step process of coprecipitation and polymerization. The batch adsorption results indicated that the highest adsorption capacity could be reached over the wide pH range of 4.0–6.0. The adsorption isotherms and kinetic studies suggested that the Cd(II) adsorption followed a pseudo second-order model and the Langmuir model, took place in monolayer coverage, and was strongly controlled by chemisorption. The formation of ternary surface complexes through cross-linked nitrile groups under cadmium-promoted bridging type improved Cd(II) adsorption capacity. The thermodynamic studies are an indicator of endothermic reaction, which describes the feasible and spontaneous nature of Cd(II) adsorption behavior in the view of temperature from 20°C to 40°C. The maximum adsorption capacity of adsorbent for Cd(II) (270.27 mg g−1) was higher than those of most of previous researches. The magnetic graphene oxide (GO)-based nanocomposite was synthesized via a two-step process of co-precipitation and polymerization by polyacrylonitrile (PAN).