Mathematical Modeling of Controlled-Release Kinetics of Herbicides in a Dynamic-Water-Bath System
Release of herbicides from lignin-based formulations follows a diffusion-controlled mechanism. For mathematical modeling of diffusive transport, the conventional approach is to assume sink conditions at both surfaces of polymeric matrix. This boundary condition proved to be inadequate to describe experimental data obtained in a water dynamic bath system. However, satisfactory descriptions for this system were obtained when a stagnant unstirred layer of herbicide solution was used as the boundary condition. The adequacy of the model incorporating this new boundary condition was statistically tested using the Fisher test at a confidence level of 95% and plotting the residual distribution.
Index EntriesMathematical modeling controlled release herbicides lignin anetryn diuron diffusion
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- 1.Wilkins, R. M. (1990), in Controlled Delivery of Crop-Protection Agents, Wilkins, R. M., ed., Taylor & Francis, London, pp. 149–165.Google Scholar
- 2.Cotteril, J. V., Wilkins, R. M., and Silva, F. T. (1995), J. Controlled Release 40, 135–142.Google Scholar
- 3.Ferraz, A., Souza, J. A., and Silva, F. T. (1992), in Proceedings of the 2nd Brazilian Symposium on the Chemistry of Lignins and Other Wood Components, vol. 3, UNICAMP, Campinas, Brazil, pp. 173–177.Google Scholar
- 4.Reis, M. F. (1999), MSc thesis, Faculdade de Engenharia Química de Lorena, Departamento de Biotecnologia, Lorena, Brazil.Google Scholar
- 5.Pereira, F. M., Gongalves, A. R., Silva, F. T., Ferraz, A., and Oliveira, S. C. (2000), in Proceedings of the 6th Brazilian Symposium on the Chemistry of Lignins and Other Wood Components, Silva, F. T. and Ferraz, A., eds., in press.Google Scholar
- 7.Siegel, R. A. (1989), Controlled Release of Drugs: Polymers and Aggregate Systems, Morton Rosoff ed., VCH, New York, pp. 1–9.Google Scholar
- 8.Crank, J. (1976), The Mathematics of Diffusion, 2nd ed., Oxford University Press, Bristol, England.Google Scholar