Repositori URV

Identifier: TDX:286

Handle: https://hdl.handle.net/20.500.11797/TDX286

Authors:
Gastó Heras, Josep Maria

Abstract:
. A complete transport model for organic compound migration in the unsaturated soil zone under non-isothermal conditions must include a detailed description of mass and energy fluxes. In this work a model is presented, which considers four different mass balances: one for the liquid phase, one for the gaseous phase as a whole, one for the water vapor and, finally, one for the organic compound. The energy balance considers conductive, convective and dispersive transport for each phase. The energy top boundary condition takes into account downwards and upwards radiative fluxes, convective flow to the atmosphere and energy transport into the soil. Simulation results obtained for the water transport under non-isothermal conditions agree with experimental results reported in the literature for soils that dry progressively. Benzene and Lindane have been chosen as examples of volatile and non-volatile organic compounds, respectively. Simulation results for volatilization flux exhibit periodic variations due to the temperature and humidity diurnal cycle. In the case of Lindane amplitudes as high as one order of magnitude have been observed.