A Review and Evaluation of Selected Kinetic Models and Sorption Processes in Amended Soils

Abstract

The main aim is to evaluate the validity of some of the models to be used for soil systems. Soil is a major reservoir for contaminants, and it possesses an ability to bind chemical elements and compounds within its particulate mass. These chemicals can exist in various forms in soil and different forces keep them bound to soil particles. It is essential to study these interactions because the toxicity of chemicals may strongly depend on the form in which they exist in the environment.  Many researchers have been using kinetic models to simulate the adsorption process with respect to time. The study of sorption kinetics is significant as it provides valuable insights into the reaction pathways and into the mechanism of sorption reactions. In addition, kinetics models describe the solute uptake rate which in turn controls the residence time of sorbate uptake at the solid–solution interface. These soils and amended soils may be used as landfill liners; hence along with strength its sorptive or retentive capacity of these soils has to be understood. Four kinetic models namely pseudo first order, pseudo second order, Elovich and intraparticle diffusion models are reviewed to understand different soil based and non soil based adsorbents. Comparisons are made between the four kinetic models based on the published literature. Pseudo second order, Elovich and intraparticle diffusion are superior models which can be used on soil systems. The pseudo first order might not be suitable for most of the soil systems.