Heavy Metal Removal from Electroplating Wastewater Using Polymer Ligand Composed of Bamboo Cellulose

Abstract Bamboo fibers fabricated via free radical polymerization reaction were used to prepare environmentally friendly and practically useful poly(acrylonitrile)-graft-cellulose (PAN) material. Herein, acrylonitrile monomer was used to prepare a cellulose grafted poly(acrylonitrile) polymer. The base-catalyzed reaction was used to convert the cyano groups of poly(acrylonitrile) into amidoxime groups using hydroxylamine, yielding poly(amidoxime) ligand. These materials were characterized by conventional spectroscopy techniques. Then, poly(amidoxime) ligand was used for metal adsorption studies. Thus, the evaluation of the adsorption through poly(amidoxime) ligand with the metal ions, Fe²⁺, Zn²⁺, Cu²⁺, Ni²⁺, and Co²⁺, was conducted using synthetic metal ions in aqueous solutions. Sorption studies reveal that all metal bindings are pH-dependent and it may reach up to pH 6. The binding capability of the ligand with Fe²⁺, Zn²⁺, Cu²⁺, Ni²⁺, and Co²⁺ was found to be 288.5, 205.8, 311.6, 220.9, and 248.4 mg g⁻¹, respectively. The isotherm study showed that the Langmuir linear model is an excellent fit for all metal ions, indicating monolayer adsorption. Finally, industrial electroplating wastewater was used to assess the feasibility of metal recovery using a polymer adsorbent, which showed that up to 99% of metals can be recovered from wastewater.