Electrospun poly(acrylic acid)/poly(vinyl alcohol) nanofibrous adsorbents for Cu(ii) removal from industrial plating wastewater

Abstract

Nanofibrous adsorbents were fabricated by electrospinning with a blend solution of poly(acrylic acid) (PAA) and poly(vinyl alcohol) (PVA) polymers and used for copper (Cu(II)) removal from industrial plating wastewater. Fourier-transform infrared spectrometry analysis demonstrated that a new peak appeared at 1617 cm⁻¹ due to the interactions between Cu(II) and carboxyl oxygen on the surfaces of the PAA/PVA nanofibrous adsorbents during Cu(II) removal in the plating wastewater. X-ray photoelectron spectroscopy analysis showed that the Cu 2p peak at a binding energy of 932 eV appeared in a wide scan of the nanofibrous adsorbents after Cu(II) removal in the plating wastewater. The carboxyl groups on the surfaces of the nanofibrous adsorbents could provide sorption sites for Cu(II) removal. Laboratory experiments in synthetic solutions showed that the nanofibrous adsorbents were effective in Cu(II) removal. The nanofibrous adsorbents had a maximum Cu(II) removal capacity of 49.3 mg g⁻¹ with a far higher selectivity for Cu(II) over Ni(II) in a binary system. Also, the nanofibrous adsorbents could be regenerated and reused for Cu(II) removal through successive adsorption–desorption processes. Batch experiments in industrial plating wastewater (Cu(II) concentration = 430.06 mg L⁻¹) demonstrated that the nanofibrous adsorbents had Cu(II) removal capacity of 25.8–33.6 mg g⁻¹ in the adsorbent dose of 0.4–2.0 g L⁻¹. However, the removal of other heavy metal ions (Ni, Zn, etc.) in the wastewater by the nanofibrous adsorbents was negligible. The nanofibrous adsorbents were also applied through filtration tests for Cu(II) removal from the wastewater under dynamic flow conditions.