Abstract

This work presents the 2D modelling of afermenting step during composting of a sewage sludge/barkmixture at the Aureilhan (France) WWTP. For this study thetemporal evolution of the temperature has been studied becauseit is the composting key parameter, especially for achieving thecompost sanitization. Thus, the modelling results have beencompared with experimental results. Fermenting windrows arebeing subject to weather conditions, we took into account thetemperature and humidity of the outside air in the model asboundary conditions. Results indicated that the model isconsistent with windrow A but differed from the experimentalresults for windrow B. The weather conditions had a strongimpact on the temperature profile during fermentation,especially the maximum temperature. Indeed, the maximumtemperatures did not exceed 35°C for windrow A (winter) whilethey were around 50°C for windrow B (summer). On the otherhand, the temperature rise in the windrows was faster for theexperimental measurements than for the modelled results.Finally, the experimental and modelling results showed that thewarmest temperatures were towards the center of the windrow.This trend is consistent with the suction aeration system.