This chapter aims at presenting the most common models describing the adsorption at solid/solution interfaces. Considerations are limited to the batch-type adsorption systems. The presented models are divided into two groups: models related to the equilibrium state and those describing the time-evolution of the adsorption system ('kinetic models'). A special emphasis is put on the relation between the physical models and the empirical and/or semi-empirical mathematical expressions. The issue of interpretation of the experimental data is also briefly discussed in the context of various models.
Keywords: Equilibrium modeling, Kinetics, Kinetic modeling, Adsorption, Interface, Langmuir model, Freundlich model, Langmuir-freundlich isotherm, Dubinin-radushkevich isotherm, Thermodynamic parameters, Multicomponent Adsorption, Multi-site-occupancy Adsorption, Intraparticle-pore-diffusion model, Intraparticle-surface-diffusion model.