One-step synthesis ionic liquid functionalized Co/Fe-LDH for effective removal of Methylene Blue from water: Batch and column experiment

The treatment of dye wastewater is of crucial significance for alleviating water pollution, ensuring ecological security and achieving the sustainable utilization of water resources. In this work, the 1-allyl-3-butylimidazolium chloride ionic liquid modified Co/Fe-LDH (Co/Fe-LDH@IL) was successfully synthesized and explored for elimination Methylene Blue (MB) from aqueous solutions. Characterizations revealed that the incorporation of ionic liquids notably increased the specific surface area from 5.37 m2.g−1 to 8.15 m2.g−1. Additionally, the number of surface active sites, was significantly enhanced. For a 25 mL MB solution with an initial concentration of 300 mg.L−1, the optimal dosage of Co/Fe-LDH@IL was determined to be 30 mg, achieving adsorption equilibrium within 20 min. Under these conditions, the maximum adsorption capacity was 517.43 mg.g−1. Kinetic studies indicated that the pseudo-second-order model accurately described the process. The Langmuir isotherm model provided a better fit than the Freundlich model, indicating a homogeneous monolayer adsorption mechanism. Column adsorption experiments further validated the superior performance of Co/Fe-LDH@IL in treating MB solutions of different concentrations. The adsorption mechanism involved electrostatic interactions, interface regulation by IL molecules, and monolayer π-π interaction adsorption on imidazole functional group. Co/Fe-LDH@IL exhibits outstanding adsorption performance and stability, showing great potential for efficiently treating MB-containing wastewater.