Recycling of Chitosan-Source Waste to Remove Heavy Meta Ions from Polluted Water

Abstract

Ion exchange resins, which are essential for water purification, have seen a major increase in use over the past 20 years due to industrial expansion. They are used to remove heavy metals, which are one of the most widespread pollutants, considering that these notoriously toxic metals can end up in ecosystems via several pathways. The chemical structure of chitosan extracted from the shrimp shell was confirmed by Fourier transform infrared (FTIR) and Proton nuclear magnetic resonance (1H-NMR) characterization. It was used as an ion exchange material for the removal of heavy metal ions Fe(III), Cd(II), and Pb(II) from their aqueous solutions in polluted water treatment, and the samples were tested by flame atomic absorption. The analytical study started by exploring the influence of pH (2, 4, 6, and 8) on the removal process by chitosan resin in a batch system. The obtained results revealed that as the pH of the analyzed ion solution increased, the removal efficiency for ions also increased. The highest removal efficiencies were obtained at pH 8 for the investigated Pb(II) and Fe(III) ions, ranging from 94.62 to 96.0, respectively, and 99.98% for Cd(II) ions at pH 6.