Modeling the Process of Sorption for the Purification of Waste Water from Petroleum Products and Heavy Metals

Fixed-bed adsorption is widely applied for the purification of liquid mixtures, including industrial waste water. The adsorption purification of waste water from petroleum products and heavy metals with the use of peat is modeled. A process model taking the longitudinal stirring of the liquid-phase flow, the outer- and inner-diffusion resistance of flow in sorbent grains, and the phenomena of adsorption on the peat surface into account is constructed. The results of experimental studies are presented. The effect of the abnormal diffusion of heavy metal ions in peat has been revealed and explained. Based on these studies, the isotherm of petroleum product adsorption from waste water and the change in the mass transfer coefficient depending on the adsorption value were plotted. The effect of chemical kinetics on the ion-exchange rate has been experimentally determined. The experimental curves of the adsorption of heavy metal ions are processed using the equations of diffusion and chemical kinetics. Based on these results some conclusions have been made.