Adsorption efficiency of sulfonated poly (ether ether ketone) (sPEEK) as a novel low-cost polymeric adsorbent for cationic organic dyes removal from aqueous solution

Abstract

The aim of this study is to investigate the methylene blue (MB) and basic violet 16 (BV16) as cationic organic dyes adsorption on sulfonated poly(ether ether ketone) (sPEEK) in aqueous solution. sPEEK was synthesized, then characterized by FTIR, SEM, TGA, BET/N2 surface area analysis, particle size and zeta potential measurements. Batch experiments were performed to analyze the effects of key parameters such as contact time, initial concentration and pH on MB and BV16 adsorptions. Additionally, temperature effect was investigated for MB adsorption. Kinetic data revealed that cationic dyes adsorptions were well-fitted by pseudo-second order kinetic model. The required times to achieve equilibrium were determined as 40 and 20 min for MB and BV16, respectively. The adsorptions showed Langmuirian character, and the maximum adsorption capacities were found to be 98.04 mg/g (0.29 mmol/g) for MB, and 181.8 mg/g (0.50 mmol/g) for BV16. The thermodynamic data showed that the MB adsorption was an endothermic process occuring spontaneously at room temperature. Desorption and recycling experiments showed that the adsorption efficiency decreased from 99.6% to 99.2% after the fifth cycle, pointing out sPEEK reusability for MB removal. Low desorption percentage of BV16 loaded sPEEK shows that sPEEK may be used for immobilizing of BV16.