Adsorption Properties of Methylene Blue from Aqueous Solution onto Thermal Modified Rectorite

The thermal modified rectorite (TR) was prepared and characterized by x-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. The structure of TR was destroyed gradually with increasing the calcination temperature, and the adsorption capacity for methylene blue (MB) of the rectorite can be improved by thermal modification in appropriate temperature ranges. The equilibrium data were well described by the Langmuir model. The kinetic studies indicated that the adsorption process was fitted well with the pseudo-second-order kinetic model. Thermodynamic studies indicated that adsorption of MB was endothermic in nature and favorable with the positive Delta H-0 value of 25.90 kJ/mol.