DEVELOPMENT OF A DYNAMIC MODEL FOR THE DEGRADATION OF FATS, OILS AND GREASES DURING CO-COMPOSTING OF OLIVE MILL SOLID AND LIQUID WASTES

Olive pomace or Olive Mill Solid Residue (OMSR) is the solid residue derived from the olive oil extraction process and it can be used as raw material in a composting process from which a high nutritional soil conditioner could be produced. Lipids are difficult to be biodegraded by aerobic microorganisms during the thermophilic composting period, and hence, a prolonged lag phase is observed with a very slow temperature increase when Fats, Oils and Grease (FOGs) are present. The objective of this study is the development of a dynamic model that can predict the biodegradation of a III-phase OMSR FOGs content during a composting period using industrial scale data of Water Holding Capacity (WHC), pH and Oxygen Uptake Rate (OUR). The created dynamic model was based on the theory of time series analysis and the theory of statistical analysis of residuals. The model was validated in a batch OMSR co-composting system with OMWW (Olive Mill Waste Water) and gave a prediction efficiency of 91%.