Managing Municipal Solid Waste: Energetic and Environmetal Comparison among different options

Abstract

Goal. This research aims to assess the environmental effects of integrated strategies in a municipal waste management system. In particular, analysis is focused on a waste stream in Palermo, where landfill involves the prompt disposal of the most waste after collection. The current local management system is compared with two integrated waste management alternatives. Both the options comply with Italian regulations, but each one predicts adopting the available technologies in different ways. Methods and objectives. Energetic and environmental balances are carried out in each management system referring to local waste composition in order to quantify energy consumption, the recovery of material and energy, and the environmental releases. Impact assessment is carried out to define the environmental profile of each option. Impact categories are defined and inventory data, by means of a suitable aggregation, can be used to evaluate the potential contribution that system inputs and outputs could bring to the relative category. Results. In opposition to the current management, which involves energy balance at a loss, the mass and energy balances outcomes in both of the two hypothetical management systems show the capability to obtain energy and material recovery to a substantial extent. Sorted collection plays a remarkable role in the improvement of environmental performance of management systems. In particular, the thermal treatment of waste associated with energy recovery, and the concomitant material recycling, increase the saving of energy. Conclusions. Environmental pressure factors of the management system are assessed depending on the relevant consumption of raw materials and energy, and on the emission of pollutants. The resulting figures reflect the two different integrated management options as being sustainable solutions for achieving an improvement in environmental performance, which is based on increasing the value of waste, as an alternative to resources, and the reduction of environmental releases. Life Cycle Assessment of municipal waste management systems can be usefully applied to define synthetic indices of environmental impact. These indices could single out possible alternatives in multi-criteria analysis, together with economic and technical parameters.