Nanofibrous material of n-succinyl chitosan/ polyethylene oxide in the removal of emerging pharmaceuticals from aqueous solution by adsorption/desorption method

Abstract

Pharmaceutical metabolites and their residues have been identified as major environmental pollutants in aquatic ecosystems. N-succinyl chitosan (NSCS) was studied as a potential adsorbent for a pharmaceutical residue, fluoxetine, from aqueous media. NSCS was investigated using Fourier transform infrared (FTIR) and 1H-nuclear magnetic residence (NMR) spectroscopies. Scanning electron microscopy (SEM) was used to investigate the formation of nanofibers by electrospinning of these green biomaterial polymer membranes. The mechanisms of FLX adsorption, as well as the effects of pH value in the original solution on adsorption capacities, were investigated using high-performance liquid chromatography (HPLC-UV DAD) under identical adsorption conditions. It was found that NSCS/PEO nanofibers with a diameter of 183 ± 38 nm were more effective to remove pharmaceutical residues from aqueous media than other commercial and modified adsorbents such as activated carbon (AC). FLX adsorption on NSCS/PEO nanofibers was favoured at pH 8.0. Pseudo-first order model was the more adequate to represent the kinetic data, being the maximum adsorption capacities of FLX on NSCS/PEO reached up to 70%. A study of the desorption potential and reusability of the mat was also conducted. According to the results, electrospun NSCS/PEO mats can be desorption and reused up to 4 times without significant loss in adsorption capability.