IMPROVING COMPOSTING TREATMENT THROUGH MODELLING: CONCEPTION OF AN IN-VESSEL COMPOSTING MODEL

An in-vessel 300-litre pilot composting treatment was studied. Three steps were considered to set up the composting model. First, the biological reactions were studied thanks to a respirometric method and modelled. Second, the gas hydrodynamics was studied in the composting pilot by using a gas tracing method, and the gas flow pattern model was then used to propose heat and mass transfers models within the composting pilot. Third, the biological and transfers models were compiled in a one-dimension com-posting model, programmed and solved with a Scilab software. The model allows to predict the biodegra-dable organic matter fractions content, the temperature, the oxygen content and the compost water content through the composting mass all along the treatment. First results were obtained with initial experimental data and non-calibrated parameters. The model has now to be well calibrated and further validated on com-plementary experiments. This study was led in the frame of a PhD work funded by Suez-Environment, th