Life Cycle Assessment and economic evaluation of the recovery of materials in an urban waste management system

The main aim of this study was to perform a Life Cycle Assessment (LCA) as well as an economic evaluation of the recovery of recyclable materials in an urban waste management system. Urban waste is mainly composed of three fractions: 1) putrescible materials, 2) recyclables materials, and 3) residual waste. The putrescible materials have to be collected separately and sent to composting and/or anaerobic digestion plants. The recyclables materials have to be sorted and sent to the proper industrial facilities. Finally, the residual waste could be further selected to be sent to energy recovery plants. If citizens separate erroneously urban waste fractions, they produce both environmental and economic damages. In fact, on the base of the Extended Producer Responsibility (EPR), a municipality receives an economic amount for each kilogram of packaging waste collected. In Italy, this activity is managed by CONAI (a private system, created and designed by companies). The “CONAI system” is based on the activities of six consortia each dedicated to promoting and control the most used materials in the packaging production i.e. steel, aluminum, paper, wood, plastics and glass. Packaging waste that goes into the dry residue represents an economic damage (a loss of the “CONAI contribution” and the payment of the disposal fees) as well as an environmental burden. The environmental and economic evaluation was performed for the case study of Nola (39.19 km², 34.349 inhabitants, and 876.47 ab./km²) in the Province on Naples, in the Campania Region of Southern Italy. Nola has a kerbside system which assured a percentage of separate collection of 61% in 2015. The LCA analysis included the treatment and disposal phases as well as the collection and transport phases. The LCA software tool SimaPro and the following three impact assessment methods were used: ReCiPe 2008 (for the medium-term perspective Hierarchist both for midpoint and endpoint levels), Ecological footprint, and IPCC 2013 (100 years). The environmental (Figure 1a) and economic (Figure 1b) analysis were developed for several real and hypothetical scenarios based on increasing percentages of separate collection and different composition analyses of the residual waste (RW). The obtained results confirmed that recovering materials from residual waste is a benefits both in environmental and economic terms. Finally, it is also a social potential benefit because the municipality could invest the economic saving in environmental campaigns entrusted to young people in an area with a high rate of youth unemployment. Please click Additional Files below to see the full abstract

Integrated environmental analysis of urban waste separate collection in the Sorrento peninsula, in Italy

The main aim of this work was to study the kerbside collection system of two municipalities in the Sorrento peninsula (in Italy) with an integrated approach based on the three pillars of sustainability: society, environment and economy. The studied municipality are Sorrento (16,745 inhabitants, 1,681 inhabitants/km²) and Piano di Sorrento (13,159 inhabitants, 1,793 inhabitants/km2). Piano di Sorrento and especially Sorrento are tourist towns and this obviously has an impact on the quantity and quality of urban waste. In 2014, the percentage of separate collection was 63.3% in Piano di Sorrento with a per capita production of 465.7 kg/inhabitant/year, and 63.8% in Sorrento with 775 kg/inhabitant/day. In every municipality, there is a separate collection centre (SCC). In the SCC, the citizens can deliver the recyclables from urban waste obtaining economic benefits similarly to the system described in De Feo and Polito (2015). The sociological analysis was developed by means of a structured questionnaire similar to that developed by De Feo and Polito (2015). The economic analysis was conducted in the light of the Extended Producer Responsibility (EPR) system, evaluating the money recovery from the recyclable materials theoretically contained in the residual waste. The analysis was carried out considering three real scenarios: (1) 2000, without separate collection; (2) 2008, when the Campania region of Southern Italy was suffering serious problems with the management of urban waste because the region did not have enough waste management facilities; (3) 2014, when there was an effective kerbside collection system in the two municipalities. The environmental analysis was performed for scenarios (1), (2) and (3) applying the Life Cycle Assessment (LCA) approach to the urban waste management, internal collection and external transport systems. As shown in Figure 1, in 2014, the increasing percentages of separate collection allowed to avoid the production of environmental impacts, with greater benefits for the citizens of Piano di Sorrento. On the other hand, for Sorrento it was calculated the number of theoretical additional touristic bus/day in the case of a “Zero Waste” management of the hotels in terms of avoided production of equivalent CO2. The result was obtained as the ratio between the difference of the impact produced by the hotels all operated in a normal way and the hotels all managed with a Zero Waste approach, and the impact of a single bus (as a function of the distance). Please click Additional Files below to see the full abstract