Modeling of Non-stationary Adsorption Behavior of Binary Heavy Metals to Porous Media

Non-stationary adsorption of various heavy metals, such as nickel and copper, on porous media is modeled both for the single and binary heavy metals. For modeling kinetic adsorption, firstly final equilibrium state using an existing isotherm model incorporating binary adsorption is described. For this, extended Freundlich isotherm showed good agreement with both single and binary systems. Second, the rate form of kinetic equations is applied. The advantage of the rate form is adsorption of heavy metals at an equilibrium state, which needs to be predetermined in the classical pseudo-kinetic equation, is not necessary. The simulated results are compared with the past experimental results on non-stationary adsorption of binary heavy metals, and the ordinary equation of pseudo-second-order kinetic best fits the results.