Process optimization and modeling of lead removal using maleate/PAN nanocomposite nanofibers: characterization, kinetics and isotherm studies

Abstract

This study aims to investigate the efficiency of lead (Pb) adsorption by adsorbent maleate/polyacrylonitrile nanocomposite using immersing the pristine electrospun (PAN) nanofibers. Characterizations such as field emission scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy were applied to investigate the structure of the synthesized maleate nanoparticles. FESEM image indicates the smooth surface of the PAN nanofibers and the maleate nanoparticles coating on the electrospun PAN nanofibers surface. A four-factor central composite design was employed, with six replicas at the central points to optimize the process variables. The maximum Pb removal percentage of 98.5% was achieved at the initial concentration of 25 mg/L, an adsorbent dosage of 1.85 g/L, a pH of 6, and a contact time of 60 min. The adsorption process follows the Langmuir isotherm (R-2 = 0.99) and pseudo-second-order kinetics (R-2 = 0.99). The highest capacity of Pb ions adsorption through maleate/PAN nanocomposite was 349.15 mg/g that makes it a potential adsorbent in wastewater treatment.