ASSESSMENT OF ORGANIC WASTE MANAGEMENT METHODS THROUGH ENERGY BALANCE

In Italy, the Organic Fraction of Municipal Solid W aste (OFMSW) is nowadays landfilled or processed through aerobic composting. The Italian towns curre ntly support a high cost for OFMSW disposal and cause a high environmental impact, because of long distance s travelled from towns to a few available landfills and fewer treatment places, as well as the used waste m anagement methods. An interesting option for OFMSW is Anaerobic Digestion (AD), producing biogas and “digestate”. In this survey a theoretical biogas plant was placed near a town of Sicily Region (Italy), centra lised with reference to the area considered for pro ducing OFMSW. The distances travelled every year to transport OFMSW from the nine towns considered to the nearest composting plant and the biogas one were ca lculated using QGIS software. Therefore, the energy balance was computed for each of the four considered scenarios. Within the implementation of Integrate d Solid Waste Management (ISWM) method, AD resulted in an energy balance much higher than that of aerobi c composting. In fact, differently from composting, A D can significantly contribute to energy recovery, while retaining the nutrients in the digestate produced a nd reducing Greenhouse Gas (GHG) emissions. The use of a rational network of towns for OFMSW collection and transportation results relevant, in terms of increa sed energy balance, only in the case of composting. The refore, if AD would be implemented as OFMSW management method, by means of biogas plants, each of them placed in an area including some towns, e.g . that considered in this survey, it could highly red uce the cost and the environmental impact of waste disposal.