Modelling codigestion of food waste and waste activated sludge

Albeit Waste Activated Sludge (WAS) and Food Waste (FW) are both suitable for anaerobic digestion, their utilization in a Continuous Stirred Reactor (CSTR) presents several drawbacks; the former substrate presents a low energetic content and poor rheological properties, whereas the latter has a very high content of readily biodegradable carbohydrates leading to accumulation of VFAs and process instabilities. Codigestion could bring together the advantages of both substrates, allowing to overcome the above mentioned points of concern and to obtain remarkable methane yields in a stable and high-performing process. The aim of this study consists in determining the optimal proportion of WAS and FW for anaerobic codigestion, using the Anaerobic Model n° 1 (ADM1) to predict the methane production.