Carboxymethyl nanocellulose stabilized nano zero-valent iron: an effective method for reduction of hexavalent chromium in wastewater

Abstract

The present work describes a novel material, carboxymethyl nanocellulose (CMNc) and its use for stabilization of nano zero-valent iron (nZVI) composites. The CMNc stabilized nano zero-valent iron composite was further utilized for effective reduction of hexavalent chromium [Cr(VI)] in aqueous media. The FTIR studies showed peaks corresponding to the nanocellulose and carboxymethylation of nanocellulose (CMNc). The x-ray diffraction pattern of CMNc-stabilized nZVI composites was confirmed the presence of nZVI nanoparticles. The morphology of nanocomposites was observed by scanning electron microscope (SEM) and transmission electron microscope (TEM). The thermograms of thermogravimetric analysis showed that thermal stability of the CMNc-stabilized nZVI composites was much improved as compared to bare nZVI. The maximum adsorption capacity of CMNc-stabilized nZVI composites for Cr(VI) was 87.71 mg g−1 as determined by Langmuir and Freundlick adsorption isotherms. At a constant dose of 0.015 g, CMC-stabilized nZVI nanoparticles were able to reduce almost 100% of 15 mg l−1 of Cr(VI) in 90 min. Therefore, the CMNc-stabilized nZVI composites material showed a promising potential for the adsorption of Cr(VI) in wastewater and can impel advancements in CMNc-based nanomaterials for their application in environmental remediation of heavy metals.