Characterisation and utilisation of solid waste from coal combustion to modelling of sorption equilibrium in a bi-component system metal-dye.

It was found that the chemical enhancement of fly ash from coal combustion by tetrabutylammonium bromide treatment yields an effective and economically feasible material for the treatment of chromium and basic dye Rhodamine B containing effluents. Characterisation of coal fly ash and treatment with tetrabutylammonium bromide were done by using a Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, confocal three-dimensional microscope, X-ray diffraction and laser particle sizer. The studies of equilibrium in a bi-component system by means of extended Langmuir, extended Langmuir-Freundlich and Jain-Snoeyink models were analysed. The estimation of parameters of sorption isotherms in a bi-component system metal-dye has shown that the best-of-fit calculated values of experimental data for both sorbates have been the Jain-Snoeyink model and the extended Langmuir model, but only in the case of a Rhodamine B. The maximum monolayer adsorption capacity of the fly ash-tetrabutylammonium bromide was found to be 863 mg g and 670 mg g for chromium and Rhodamine B, respectively.