The Soil model simulates chemical fate in soil, including the rates of degradation, volatilization, and leaching in water, and how long it will take for the soil to ‘recover’ to a specified or acceptable level of contamination. This model may be useful for simulating chemical spills or to assist in pesticide selection.
The Soil model is a Level III model that provides a non-equilibrium steady-state assessment of chemicals in soil-based environment. Three types of neutral organic chemicals are treated: chemicals that partition into all media (Type 1), involatile chemicals (Type 2), and chemicals with zero or near-zero solubility (Type 3).
The model treats the following processes: volatilization, water leaching, and reaction. Default environments present in the model include a carrot field, a potato field, and soil with no vegetation present. Environments can be modified and added to the database by the user.
Features of the Soil model:
- Provides a database of chemicals and chemical properties.
- Permits temporary additions/changes of chemicals and their properties to a simulation.
- Permits permanent additions, changes and deletions of chemicals and their properties to the database.
- Provides standard environments for chemical comparison, including a carrot field, potato field, and soil.
- Permits temporary and permanent changes/additions of environments
- Provides context-sensitive Help.
- Displays and prints the model calculations, as performed by the program.
- Allows the printing of simulation tables, summary diagrams, and a small selection of charts.
- Allows the program results to be saved as a comma separated value (csv) file, readable by many spreadsheet programs such as Excel.
This program was based on the following publications:
- Parnis, J.M., Mackay, D. “Multimedia environmental models: the fugacity approach”. 3rd ed. CRC Press, Taylor & Francis Group. Boca Raton, FL. 2021.
- Jury, W.A, Spencer, W.F., Farmer, W.J. “Behaviour assessment model for trace organics in soil: I model description”. J. Environ. Qual. 12, 558, 1983.
The required input data are:
Chemical Properties
- Molar mass
- Data collection temperature
- Henry’s law constant
- Log KOW
- KOC
- KMW
- Degradation half-life
Environmental Properties
- Chemical dosage in soil
- Model output includes:
- Z and D values
- Soil fugacity
- Concentrations and amounts in each compartment
- Residence-times associated with each process
- Transfer rates for each process
- Summary diagrams
The program is available as an Excel spreadsheet which is still in the "beta" test phase. Please report any problems to Prof. Mark Parnis.
Please read the software license before downloading the software. Use of the software constitutes your agreement to abide by the terms and conditions set out in the license agreement.