Desarrollo de MODUELO 2herramienta para la evaluación de la contaminación producida en vertederos de residuos sólidos urbanos

Resumo

This work presents a new version of the landfill dynamic simulation program "MODUELO", developed by the Environmental Engineering Group of the University of Cantabria (Spain). Based on the user input of landfill characterization data, the program calculates the daily leachate flow and organic pollution and the generation and composition of biogas. The hydrologic and the biodegradation models, which constitute the principal body of the program, have been improved in the new version, called "MODUELO 2". The mathematical expressions for the calculation of the surface balance and the saturated flow between the cells that compose the landfill model have been corrected. The runoff effect on the leachate flow and a model for the variation of the waste permeability as it is buried have now been included, as well as an improved biodegradation model. As a first checking of the new version it has been applied to the landfill of reference, Meruelo I (Spain). The modified hydrologic model results are compared to the available data and other models: MODUELO 1 and HELP (developed by the E.P.A. of the U.S.A.). Having calibrated the hydrologic part, the biodegradation model is then evaluated by contrasting its results with the available data and the general emission tendencies found by other authors in different facilities. The results of a sensitivity analysis of this part are also presented. Finally, the applicability of the new program to other landfills is confirmed by simulating another European facility, which has been called "X". The hydrologic and biodegradation simulation results in both landfills are quite close to the available data, but the quality and quantity of these series prevent the validation of the models. This shows the need for a "specific to modelling" data acquisition in those landfills which want to make use of this kind of tool for the design, management and monitoring of environmental protection measures.