Waste fiber-based cellulose supported polymer ligands for toxic metals removal from industrial wastewater

Heavy metals pollution in the wastewater is a drastic situation hence a powerful and economical treatment technology is needed for the water purification. For that reason some pure cellulosic materials were extracted from waste fiber and further modification of the cellulose was performed by free radical grafting reaction resulting the poly(methyl acrylate)-grafted cellulose and poly(acrylonitrile)-grafted cellulose. Consequently, poly(hydroxamic acid) and poly(amidoxime) ligands were prepared from the grafted cellulose. The adsorption capacity (q_e) of some toxic metals ions with the polymer ligands was found excellent, e.g. copper capacity (q_e) for poly(hydroxamic acid) is 375 mg/g whereas q_e for poly(amidoxime) ligand is 355 mg/g at pH 6. Other metal ions (iron, chromium, cobalt, zinc and nickel) show significance binding properties at pH 6. The Langmuir and Freundlich isotherm studies were also performed and Freundlich isotherm model showed good correlation coefficients for all metal ions, indicating that multiple-layers adsorption occurred. The both polymeric ligands showed outstanding heavy metals removal magnitude from the industrial wastewater, up to 90-98% of toxic metal ions can be removed from industrial wastewater.