Fabrication of novel eco-friendly hybrid biocomposites based on carboxymethyl chitosan /polypropylene glycol @ activated carbon for the efficient removal of Cr (III) from the aquatic medium

ABSTRACT

Different nonionic biocomposite frameworks were prepared by supporting carboxymethylated chitosan polypropylene glycol on active carbon and characterized using FTIR, XRD, and SEM. The prepared biocomposites comprised different modified chitosan to active carbon ratios. The biocomposites were achieved during the remediation of chromium (III) ions from an aqueous medium. The influences of pH, chromium (III) ions concentration, time, and weight used in the remediation process were extensively studied to point out the optimized process conditions. The assigned optimum conditions of chromium (III) ions remediation were as follows: 25°C, using 0.5 g sorbents, and 100 ppm of ions concentration for 300 min at semi-neutral to neutral pH range of 6–7 to attain removal efficiency of 98.1%. The process was followed by Freundlich adsorption isotherm and pseudo-second-order kinetics. The accumulation of ions onto biocomposites was regulated according to the intraparticle diffusion model. Increasing the active carbon-modified chitosan ratio in the biocomposites from 1:4 to 4:1, enhanced the remediation effectiveness of carboxymethylated chitosan in terms of equilibrium adsorption capacities increase from 67.93 to 70.25 mg/g. An opposing attitude was achieved by increasing the incorporated active carbon in the biocomposites during their antimicrobial efficiencies’ assessments. The study presents a low-cost, eco-friendly, highly effective eliminator for highly contaminated aqueous media with Cr³⁺ ions. Furthermore, the prepared adsorbents exhibited high elimination efficiency in the presence of a high abundance of Cr³⁺ in the medium.

KEYWORDS:

• Carboxymethylated chitosan
• active carbon
• chromium (III) remediation
• antimicrobial activity
• Freundlich adsorption isotherm

Acknowledgments

I would like to thank Taif University Researcher supporting project number (TURP-2020/243), Taif University, Taif, Saudi Arabia.

Disclosure statement

No potential conflict of interest was reported by the author(s).