An eco-friendly chitosan-diethylaminoethyl cellulose composite: In-depth analysis of lead (II) and arsenic(V) decontamination from water with molecular perspectives

Water pollution from heavy metal ions, such as lead (II) and arsenic (V), is a widespread problem that has spurred researchers to look for efficient, environmentally acceptable treatment methods. In this context, the present study explores the potentiality of a novel, low-cost biosorbent material for the efficient removal of these toxic contaminants. A chitosan crosslinked@diethylaminoethyl cellulose (Cs@DEAE-C) composite was synthesized by crosslinking chitosan and diethylaminoethyl cellulose (DEAE-C) and employed to adsorb Pb(II) and As(V) from water. The monolayer adsorption capacity was found to be 218.71 mg/g for Pb(II) and 41.98 mg/g for As(V), respectively while the uptake process involved chemisorption. The adsorption capability of Cs@DEAE-C for As(V) and Pb(II) was decreased when phosphate and nitrate ions were present. Desorption studies demonstrated that Cs@DEAE-C effectively removed As(V) and Pb(II) for up to five adsorption–desorption cycles. Uncross-linked carbonyl (C = O) and hydroxyl (–OH) groups were found to be the main adsorptive sites for Pb(II) uptake, whereas uncross-linked hydroxyl (–OH) and –NH₂ groups were found to be crucial for As(V) absorption. The self-diffusion coefficient values from molecular dynamics (MD) simulation revealed that electrostatic interactions hinder the mobility of metal ions limiting their diffusion ability. This study highlights the efficiency of the low-cost chitosan composite for contaminant removal and suggests its potential applicability in treating real wastewater for other pollutants. Further research could focus on optimizing the synthesis process and exploring the composite's efficacy for additional contaminants.