Optimization of Treatment and Energetic Valorization of Chicken Droppings by Anaerobic Digestion

Abstract

Morocco produces, all over the kingdom, over 500000 tons of droppings of chicken per year. Those organic wastes are considered a potential source of environmental contamination. In this work, we recommend the anaerobic digestion of chicken droppings by new inoculums from the treatment plant in Belgium station. The biodegradation of this waste consists of incubating a methanogenic inoculum with the waste in batch digester. The biogas production is measured by manometer and the composition of this biogas was analyzed by gas chromatography. The pressure measurements provide information on the amount of biogas produced, but the analysis of gas chromatography provides information about different gas content in biogas production. This treatment generates a high quantity of biogas in the order 230,58 ml/gCOD substrate during 49 days of incubation equivalent 207 m3/t DM. The analysis of the composition of gases into biogas is composed of 60,2 % methane and 38,8 % carbon dioxide and 0 % of hydrogen. So it has a high lower heating value of order 5,9 kWh/m3. This quantity of methane (138,97 ml/g COD) confirms that the anaerobic digestion is a good way of treatment for this waste. The importance of using a pretreatment (heating and milling) prior to anaerobic digestion of these wastes and use this inoculum (sludge of plant treatment).