Magnetic chitosan nanoparticles as a potential bio-sorbent for the removal of Cr(VI) from wastewater: Synthesis, environmental impact and challenges

Abstract

The efficient removal of Cr(VI) from the contaminated wastewater is an essential issue before discharge in a watercourse. Adsorption is viewed as the most promising technology for the removal of Cr(VI) because of its distinct advantages, including low operating cost, ease of operation, design simplicity, low maintenance, and high efficiency. Chitosan is a natural biopolymer with amine (-NH2) and hydroxyl (-OH) groups in its structure. The non-toxic, biodegradable, biocompatible, hydrophilic, and anti-bacterial nature of chitosan nanoparticles makes it an ideal bio-sorbent for the removal of heavy metal ions from contaminated wastewater. Weak mechanical strength, separation difficulties of chitosan nanoparticles from the aqueous phase, recyclability, and reusability are the potential limitations of utilizing the chitosan particles as a potential adsorbent for the removal of heavy metal ions from wastewater. There is increasing attention in fabricating magnetic chitosan nanoparticles (M-Ch-NPs) with surface modification of chitosan nanoparticles using magnetite to enhance the mechanical strength, reusablity and minimize the separation difficulties of chitosan nanoparticles from the aqueous phase. The present study reviews the various fabrication methods of chitosan nanoparticles and its utilization, environmental impacts, and challenges of utilizing M-Ch-NPs as an adsorbent for the Cr(VI) from contaminated wastewater.