| Abstract: | Batch adsorption experiments were carried out for the removal of ofloxacin from aqueous solution using modified coal fly ash
as adsorbent. The effects of various parameters such as contact time, initial solution concentration and temperature on the
adsorption system were investigated. The optimum contact time was found to be 150 min. The adsorption isotherm data fit well
with the Langmuir model, and the kinetic data fit well with the pseudo-second order and the intra-particle diffusion model.
Intra-particle diffusion analysis demonstrates that ofloxacin diffuses quickly among the particles at the beginning of the
adsorption process, and then the diffusion slows down and stabilizes. Thermodynamic parameters such as ΔG, ΔH, and ΔS were also calculated. The negative Gibbs free energy change and the positive enthalpy change indicated the spontaneous and
endothermic nature of the adsorption, and the positive entropy change indicated that the adsorption process was aided by increased
randomness. |
