Graphene oxide grafted MgO doped activated carbon for efficient remediation of hexavalent chromium [Cr(VI)] contaminated water

Abstract

Hexavalent Chromium [Cr(VI)] is a classified group 1 carcinogen that demands instantaneous and permanent removal from the environmental media. Amongst the removal techniques adsorption is considered one of the most efficient Cr(VI) remediation options because of its low operating costs, high removal efficiency, simplicity of design and implementation. Graphene oxide based metallic nanocomposites are efficient adsorbents of heavy metals both owing to the large surface area of the metallic nanoparticles and diverse functional groups of GO having an ideal potential not only as an efficient adsorbent but also as a stabilizing material for nanoadsorbents which suffer from agglomeration and loss of active adsorption sites. In the current study, a novel GO grafted magnesium oxide doped activated carbon (GO@MgO/AC) composite adsorbent was synthesized. The asprepared GO based nanocomposite was applied as an efficient nanoadsorbent to remove Cr(VI) ions from aqueous media. FE-SEM, FTIR, BET, and XRD characterization techniques were conducted to study the morphology, pore size, surface area, crystallinity, and phase purity of the nanocomposite. The study was conducted in batches at different experimental parameters to evaluate the effect of adsorbent dose, solution pH, initial adsorbate concentration and contact time on adsorption performance of the adsorbent. The adsorbent showed up to 99.99% adsorption of Cr(VI) at 100 mg/L of initial adsorbate concentration at an adsorbent dose of 6 g/L with a 1:1 GO: MgO@AC ratio at a pH range of 3 to 7. The study demonstrates the promising potential of GO grafted MgO doped activated carbon for efficient and sustainable adsorptive remediation of heavily chromium VI contaminated water from several chemical process industries and mining plants.