Preparation of Sulfonated Polystyrene-Iron Composite Material and Study of Their Cationic and Anionic Dyes Adsorption Properties

Abstract

A sulfonated polystyrene-iron composite magnetic material (PSSFe), which is nonpolluting, was synthesized using high-temperature reflux in a simple system. It was applied for the first time to the adsorption and removal of two dyes (methylene blue (MB) and congo red (CR)) from wastewater. The cost of synthesis is lower and simpler and then that of the large sites active in PSSFe, making it efficient cost effective for a large variety of dyes. Scanning electron microscopy (SEM), x-ray diffraction (XRD), thermogravimetric analysis (TGA-DTGA), infrared spectroscopy (FTIR), and the pH of the point of zero charge (pHPZC) were used to characterize the morphology and microstructure of the magnetic sample. The adsorption of methylene blue and congo red as a function of various factors, such as the effect of pH, time and temperature, was investigated. The results demonstrated that the Langmuir model well represented the isotherms, supporting monolayer and homogeneous adsorption, and the pseudo-second-order model could also capture the kinetic process of adsorption. The PSSFe exhibited adsorption capabilities (qe) of 99.7 and 76.9 (mg/g) for MB and CR, respectively. The adsorption of MB on PSSFe was endothermic, whereas the adsorption of CR on PSSFe was exothermic. During the first cycle, both MB and CR were successfully desorbed from PSSFe, with 99.7% and 92.5% removal percentages, respectively.