Adsorptive Recovery of Cu²⁺ from Aqueous Solution by Polyethylene Terephthalate Nanofibres Modified with 2-(Aminomethyl)Pyridine

Abstract

The accumulation of plastic waste products in the environment has adversely affected wildlife and human beings. Common plastics that accumulate in the environment are plastics that are made of polyethylene terephthalate (PET) polymer. PET plastic waste products can be recycled for beneficial use, which would reduce their negative impacts. In this study, modified PET or waste PET (WPET) from plastic bottles was blended with powder commercial 2-(aminomethyl)pyridine (SiAMPy) resin and electrospun into composite nanofibres and applied for Cu2+ adsorption. PET-SiAMPy or WPET-SiAMPy composite nanofibres fibre diameters from the HRSEM images were 90–140 nm and 110–155 nm, respectively. In batch adsorption experiments, PET-SiAMPy or WPET-SiAMPy composite nanofibres achieved Cu2+ adsorption equilibrium within 60 secs of contact time with 0.98 mmol/g (89.87%) or 1.24 mmol/g (96.04%) Cu2+ adsorption capacity. The Cu2+ complex formation rate (k) with WPET-SiAMPy was 0.0888 with the mole ratio of Cu2+ and WPET-SiAMPy nanofibres 1:2. The complex molecular formula formed was Cu(WPET-SiAMPy)2 with a square planar geometry structure. The WPET-SiAMPy nanofibres’ adsorption was best fitted to the Freundlich isotherm. WPET-SiAMPy composite nanofibres were considered highly efficient for Cu2+ adsorption from aqueous solution and could be regenerated at least five times using 5 M H2SO4.

Keywords

• waste plastic
• polyethylene terephthalate
• electrospinning
• 2-(aminomethyl)pyridine
• adsorption
• copper ion