Carmen Ferrara

Investigation of the environmental impacts of municipal wastewater treatment plants through a Life Cycle Assessment software tool

ABSTRACT This paper investigates the total and per capita environmental impacts of municipal wastewater treatment in the function of the population equivalent (PE) with a Life Cycle Assessment (LCA) approach using the processes of the Ecoinvent 2.2 database available in the software tool SimaPro v.7.3. Besides the wastewater treatment plant (WWTP), the study also considers the sewerage system. The obtained results confirm that there is a ‘scale factor’ for the wastewater collection and treatment even in environmental terms, in addition to the well-known scale factor in terms of management costs. Thus, the more the treatment plant size is, the less the per capita environmental impacts are. However, the Ecoinvent 2.2 database does not contain information about treatment systems with a capacity lower than 30 PE. Nevertheless, worldwide there are many sparsely populated areas, where it is not convenient to realize a unique centralized WWTP. Therefore, it would be very important to conduct an LCA study in order to compare alternative on-site small-scale systems with treatment capacity of few PE.

LCA of an ice cream cup of polyethylene coated paper: how does the choice of the end-of-life affect the results?

ABSTRACT This study presents an evaluation of the environmental performance of an ice cream cup made of polyethylene (PE)/paper laminate using a life cycle assessment approach ‘from cradle to grave’. Two opposite alternative disposal scenarios, as well as their intermediate combinations, were considered: 100% incineration and 100% landfilling. The environmental impacts were calculated using the EPD 2013 evaluation method since the study was developed in an Environmental Product Declaration perspective as well as the method ReCiPe 2008 H at the endpoint level. PE/paper laminate production was the most impactful process since it provided the highest contribution to total impacts in four of six impact categories considered. Ice cream cup production was the second impactful process. The 100% incineration scenario provided negligible contribution to life cycle total impact for all impact categories; while considering the landfilling scenario, the percentage contributions to the total impact provided by the end-of-life phase increased considerably, until to be comparable to the contributions provided by the production processes of the PE/paper laminate and the ice cream cup. The obtained results highlighted that different disposal scenarios can affect significantly the conclusions of a study. At the endpoint level, incineration was more environmentally sound than landfilling for all the ReCiPe damage categories.

Environmental and economic benefits of the recovery of materials in a municipal solid waste management system

ABSTRACT The main aim of this study was to perform a Life cycle assessment study as well as an economic evaluation of the recovery of recyclable materials in a municipal solid waste management system. If citizens separate erroneously waste fractions, they produce both environmental and economic damages. The environmental and economic evaluation was performed for the case study of Nola (34.349 inhabitants) in Southern Italy, with a kerbside system that assured a source separation of 62% in 2014. The economic analysis provided a quantification of the economic benefits obtainable for the population in function of the achievable percentage of source separation. The comparison among the environmental performance of four considered scenarios showed that the higher the level of source separation was, the lower the overall impacts were. This occurred because, even if the impacts of the waste collection and transport increased, they were overcome by the avoided impacts of the recycling processes. Increasing the source separation by 1% could avoid the emission of 5 kg CO2 eq. and 5 g PM10 for each single citizen. The economic and environmental indicators defined in this study provide simple and effective information useful for a wide-ranging audience in a behavioural change programme perspective.

APPLICAZIONE DELLA METODOLOGIA LCA AL TRATTAMENTO DELLE ACQUE REFLUE

Quest’articolo propone una review di letteratura riguardante l’applicazione della Life Cycle Assessment (LCA) al trattamento delle acque reflue. Dall’analisi dei risultati degli articoli presi in considerazione, e emerso che l’LCA consente una valutazione complessiva e integrata dei sistemi di depurazione, evidenziando i reali compromessi ambientali connessi con la selezione di ogni specifica alternativa di trattamento ed evitando, cosi, le problematiche concernenti il problem shifting (con il quale si risolve un problema creandone altri). Malgrado cio, bisogna rilevare che sono necessari ulteriori studi al fine di superare le limitazioni ancora presenti in tale settore di ricerca e che riguardano principalmente l’aggiornamento dei metodi di valutazione degli impatti, al fine di tener adeguatamente conto di “nuovi” inquinanti, la scarsa disponibilita di dati d’inventario di buona qualita e la non trascurabile soggettivita dell’analisi.