Removal of Tannin from Aqueous Solution by Adsorption onto Treated Coal Fly Ash: Kinetic, Equilibrium, and Thermodynamic Studies

The study investigated the performance of tannin adsorption on treated coal fly ash. The adsorption capacity of coal fly ash could be enhanced through appropriate pretreatment by acid. There was an apparent increase of tannin adsorption when fly ash dosage changed from 0 to 20 g/L. The adsorption isotherm data fitted to Freundlich and Langmuir models. The adsorption process followed pseudo-second-order kinetics. The adsorption processes …