title: Predicting release and transport of pesticides from a granular formulation during unsaturated diffusion in porous media.
abstract: The release and transport of active ingredients (AIs) from controlled-release formulations (CRFs) have potential to reduce groundwater pesticide pollution. These formulations have a major effect on the release rate and subsequent transport to groundwater. Therefore the influence of CRFs should be included in modeling non-point source pollution by pesticides. We propose a simplified approach that uses a phase transition equation coupled to the diffusion equation that describes the release rate of AIs from commercial CRFs in porous media; the parameters are as follows: a release coefficient, the solubility of the AI, and diffusion transport with decay. The model gives acceptable predictions of the pesticides release from commercial CRFs in diffusion cells filled with quartz sand. This approach can be used to study the dynamics of the CRF-porous media interaction. It also could be implemented in fate of agricultural chemical models to include the effect of CRFs.
authors.affiliation: Soil Science and Agricultural Chemistry Group, Department of Plant Biology and Soil Science, Faculty of Sciences, University of Vigo, E-32004 Ourense, Spain; Department od Agroecology, Faculty of Science and Technology, Aarhus University, Blichers Allé 20, P.O. Box 50, DK-8830 Tjele, Denmark. Electronic address: mparadelo@uvigo.es.
authors.forename: Marcos
authors.initials: M
authors.lastname: Paradelo
authors.affiliation: Soil Science and Agricultural Chemistry Group, Department of Plant Biology and Soil Science, Faculty of Sciences, University of Vigo, E-32004 Ourense, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Soto-Gómez
authors.affiliation: Soil Science and Agricultural Chemistry Group, Department of Plant Biology and Soil Science, Faculty of Sciences, University of Vigo, E-32004 Ourense, Spain.
authors.forename: Paula
authors.initials: P
authors.lastname: Pérez-Rodríguez
authors.affiliation: Institute of Natural Resources and Agrobiology of Salamanca (IRNASA-CSIC), 37008 Salamanca, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Pose-Juan
authors.affiliation: Soil Science and Agricultural Chemistry Group, Department of Plant Biology and Soil Science, Faculty of Sciences, University of Vigo, E-32004 Ourense, Spain.
authors.forename: J Eugenio
authors.initials: JE
authors.lastname: López-Periago
mesh_terms: D016573:Agrochemicals / Q000032:analysis* / Q000737:chemistry; D005374:Filtration; D060587:Groundwater / Q000737:chemistry*; D010575:Pesticides / Q000032:analysis* / Q000737:chemistry; D012995:Solubility; D014872:Water Movements; D018508:Water Purification / Q000379:methods*
chemical_list: D016573:Agrochemicals; D010575:Pesticides
keywords: Agrochemicals; Controlled release; Diffusion; Formulation; Soil; Soil pesticide transport