Study on Cu (II) and Au (III) metal ion adsorption performance of the lignosulfonate activated carbon fiber

Abstract

Lignin-based activated carbon has received wide attention recently. While most works focus on the granular activated carbon produced by chemical activated agents, the fibrous activated carbon developed by physical activated agents is also worth attention. Therefore, the objective of this study is to characterize the lab-made, physically activated lignosulfonate activated carbon fiber (LACF) and investigate the performance and potential applicable for copper and gold ions adsorption. Electrospinning technique is used to produce the submicron-sized LACF. The features of LACF are examined through physical and chemical characterization methods. For physical properties, scanning electron microscopy (SEM) is used to examine fiber morphology, nitrogen adsorption-desorption method is applied to derive specific surface area (SSA) and pore size distribution (PSD), while SSA is further calculated through Brunauer-Emmett-Teller (BET) model, and PSD is calculated through quenched solid density functional theory (QSDFT). Chemical structures and surface properties, on the other hand, are determined through elemental analysis, Fourier-transform infrared spectroscopy (FTIR), and zeta potential analyzer. Adsorption mechanisms are studied through executing batch adsorption tests and fixed-bed column adsorption to obtain the metal ion adsorption capacity and kinetic models of LACF, and optimized through central composite design.