Chitosan/Graphene Oxide Nanocomposite Membranes as Adsorbents with Applications in Water Purification

The scope of this article is to develop composite membranes using chitosan (CS) and graphene oxide (GO) as adsorbents for the removal of inorganic pollutants such as heavy metal ions, particularly Pb²⁺, from aqueous solutions. GO was obtained by modified Hummers method and blended with CS solution. The introduction of ethylenediaminetetraacetic acid (EDTA) compound to CS/GO suspension lead to an increased adsorption capacity of CS/GO for the elimination of heavy metals by forming stable chelates with them. The synthesized membranes were examined by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), and the adsorption behaviour of Pb²⁺ from aqueous solutions using CS/EDTA/GO membranes was evaluated using inductively coupled plasma mass spectrometry (ICP-MS). The adsorption performance of Pb²⁺ ions was studied by monitoring the concentration of Pb²⁺ against the adsorption period at an initial content of the adsorbent. The maximum adsorption efficiency of Pb²⁺ metal ions reached 767 mg·g^-1 for CS/EDTA/GO 0.1%, 889 mg·g^-1 for CS/EDTA/GO 0.3%, 970 mg·g^-1 for CS/EDTA, 853 mg·g^-1 for CS and 1526 mg·g^-1 for GO. These findings show promising potential for CS/EDTA/GO membranes as effective adsorbent materials for the removal of heavy metal ions in water.