Adsorptive removal of heavy metals by a bio-based polymeric material PAO-CI from wastewater

Abstract

A novel bio-based polymeric material PAO-CI was prepared, characterized and evaluated for its sorption toward heavy metal from aqueous solution. PAO-CI was prepared using CI as a novel supporter and first surface-modified with coupling agent, γ-methacryloxylpropyltrimethoxysilane (MPS), and the polymerizable double bonds were introduced onto the surfaces of CI particles, forming the modified particles MPS-CI, followed by a graft polymerization reaction and an amidoximation reaction. The Scanning electron microscopy (SEM), Fourier transform infrared spectrum (FT-IR), X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS) were used to characterize the adsorbent. The results indicated that PAO-CI had a large equilibrium capacity toward lead ions, and the Langmuir, Freundlich and Temkin models were appropriate for fitting the equilibrium data. The maximum sorption capacity of Pb(II) determined according to the Langmuir model was 80.11 mg/g at 303 K. The Pb(II) sorption capacity was insensitive to ionic strength variation. The regeneration of the Pb(II)-loaded PAO-CI was conducted and the sorption capacity of Pb(II) maintained above 94% in six consecutive sorption/desorption cycles. Therefore, PAO-CI could serve as a cost-effective, efficient and novel adsorbent for Pb(II) removal from water.