Removal of Basic Fuchsin from water by using mussel powdered eggshell membrane as novel bioadsorbent: Equilibrium, kinetics, and thermodynamic studies

This study aims to remove organic cationic dye Basic Fuchsin (BF) by adsorption onto a low cost eggshell membrane (ESM) in batch mode at 293 K. XRD analysis confirms the amorphous nature of ESM meanwhile FTIR spectroscopy reveals the presence of several functional groups such as hydroxyl (–OH), sulfhydryl (–SH), carboxyl (–COOH), and amino (–NH2). Morphological observations by SEM indicate its fibrous microstructure. BET analysis shows a surface area of 11.56 m2 g−1 and the presence of mesopores with a volume of 6.173 10−3 cm3 g−1. The value of pHPZC of ESM is 7.05. The influence of adsorbent dose, contact time, pH, temperature and dye concentration is examined. The highest adsorption capacity around 48 mg.g−1is achieved for a dye concentration 250 ppm, pH 6 and 25 °C. In addition, adsorption has been found to follow pseudo-second order kinetics. The analysis of the experimental data using linear forms based on Langmuir, Freundlich and Temkin isotherm models indicate that the best fit is obtained with Freundlich model. Thermodynamic parameters (Gibbs free energy, enthalpy, and entropy) reveal that the adsorption of BF onto ESM is an exothermic and spontaneous process. A comprehensive mechanism for BF adsorption by ESM has been proposed. •Preparation of an amorphous eggshell membrane porous powder with high surface area.•FTIR analysis elucidated the functional groups.•A high removal rate of toxic basic fuschin of 48 mg/g has been achieved at optimized conditions.•Isotherm models tested and thermodynamic parameters determined; i.e. adsorption is an exothermic spontaneous process.•A comprehensive adsorption mechanism has been proposed.