Ytterbium tungstate nanoparticles as a novel sorbent for basic dyes from aqueous solutions

Abstract

Ytterbium tungstate nanoparticles (YTNPs) were used as a sorbent for removing methylene blue (MB), as a model cationic dye, from water solutions. YTNPs were characterized through scanning electron microscopy. The factors influencing the efficiency of the sorbent in a batch adsorption procedure (i.e., initial pH, amount of YTNPs, and contact time) were evaluated at a constant concentration of MB, and central composite design was used to determine their efficacies. The results indicated the best conditions in the case of a 200-ppm MB solutions to be 3 mg mL-1 (as the amount of YTNPs used), pH = 10, and contact time = 30 min. The adsorption kinetics, isotherm and desorption properties of YTNPs were also fully investigated. The Langmuir model was used for fitting the adsorption isotherm and the results indicated a high adsorption capacity for the model dye. The adsorption kinetics was found to comply with a pseudo-second-order behavior, which means that adsorption constitutes the rate-determining step. Furthermore, YTNPs were successfully used to remove MB from water and wastewater samples.