Enhanced removal of heavy metal chromium than lead from aqueous solution by glutaraldehyde crosslinked grafted chitosan biomass/bentonite composite

The present study investigates the potential of glutaraldehyde crosslinked grafted chitosan biomass/bentonite composite as an adsorbent for the removal of Cr(VI) and Pb(II) ions from aqueous solutions. The composite was synthesized by grafting chitosan biomass obtained from crab shells with n-butyl acrylate using ceric ammonium nitrate as an initiator, followed by blending with bentonite clay in a 1:1 ratio and crosslinking with glutaraldehyde. The prepared composite was characterized using FTIR and XRD techniques. Batch adsorption experiments were conducted to determine the ideal settings for removing heavy metal ions at a constant temperature of 30 °C by adjusting pH, adsorbent dosage, contact duration, and beginning metal ion concentration. The results demonstrated the synergistic effect of the materials used in the composite, enhancing its adsorption capacity for Cr(VI) and Pb(II) ions. The adsorption capacity of the sorbent for metal Cr(VI) ions was more than that of Pb(II) ions. The removal percentage of both the metal ions was > 90%. The study highlights the potential of the Cs-g-PBA/Bent composite as an eco-friendly and cost-effective alternative to activated carbon for the treatment of heavy metal-contaminated wastewater and contributes to the development of sustainable solutions for environmental remediation and helps in promoting human health.