Chemical Kinetic Sorption and

 Transport in Soils


Chem_Transport  is a software package of  several models that describe the transport and sorption of chemicals in soils and other porous media.  These models are characterized by two main features; they are nonlinear and kinetic in nature.  The models represent our recent advances made in the understanding of transport characteristics of chemicals in soils and geological media.  The models are broad in nature and address various physical and chemical processes that influence the behavior of solutes in porous media.


Chem_Transport  models are applicable for variety of chemicals in field settings as well as controlled laboratory and greenhouse environments.

The models represent transport conditions and batch type reactors under noflow conditions where transport is ignored.  For each class of models, first simulation type models where the user provides all physical and chemical parameters.  This class of models are most suitable for classroom teaching and risk assessment. The second class of models is that where the user provides an experimentally measured data set and a selected model will provide best-fit (based on non-linear least-squares) description of measured results.


Chem_Transport models are based on solutions of the adjective-dispersive equation for the transport of chemicals in one-dimensional soils and geological media.   The solutions are based on numerical approximations using finite –difference (Crank-Nickolson) techniques.


Physical Nonequilibrium Models

• Uniform and stratified soils

• Multiple Regions

• Multiple Porosities

• Fractured Media, mobile-immobile


Kinetic Sorption Models

• Nonlinear and Langmuir Kinetics

• Desorption-Hysteresis

• Second-Order

• Kinetic Ion Exchange

• Multi-Site and Multireaction


Applications of Chem_Transport

The models presented are applicable for various chemicals including organics and inorganics, e.g., insecticides, herbicides, industrial chemicals, military explosives, and radionuclides.  Other include applied agricultural chemicals or macro nutrients; nitrogen, phosphorus and potassium, as well as essential micronutrients, e.g., boron, zinc, copper and molybdenum. Others also include heavy metals such as arsenic, lead, cobalt, cadmium, trace elements and tracer.


Teaching - Can be incorporated in classroom teaching for undergraduate and graduate students in chemical and civil engineering, hydrology, geology, soil physics and chemistry, environmental sciences and environmental engineering.  Simulations based on various scenarios provide information on system parameters (sensitivity analysis) and risk assessment.


Research -   This software should be also useful to environmental scientists, engineers, and geologists whose desire is to describe laboratory or field observations under various constraints such as batch reactors, miscible displacements, and transport in saturated and unsaturated  soils.  This software should also be useful for federal and state agencies, researchers, consulting engineers, and decision makers in the management and restoration of contaminated sites.


System Requirements

The software runs on Windows platform and a recent version of Java is required to install and execute this software on personal computers.

Input and Output Data Files

Input data files in ASCII format (txt or dat) must be uploaded to execute the different  models.  Samples of input files are included in this package.  Model output is given in txt format to be saved by the user.  Graphics of simulations and experimental measurements are also generated which can be saved by the user.  Graphics include breakthrough curves, time-dependent sorption and sorption isotherms.  Details are available in the User’s Manual.


Inquiries:  Magdi Selim

School of Plant, Environmental and Soil Science

Web page designed by Mhani