The use of life cycle assessment for the comparison of biowaste composting at home and full scale

Abstract

Environmental impacts and gaseous emissions associated to home and industrial composting of the source-separated organic fraction of municipal solid waste have been evaluated using the environmental tool of life cycle assessment (LCA). Experimental data of both scenarios were experimentally collected. The functional unit used was one ton of organic waste. Ammonia, methane and nitrous oxide released from home composting (HC) were more than five times higher than those of industrial composting (IC) but the latter involved within 2 and 53 times more consumption or generation of transport, energy, water, infrastructures, waste and Volatile Organic Compounds (VOCs) emissions than HC. Therefore, results indicated that IC was more impacting than HC for four of the impact categories considered (abiotic depletion, ozone layer depletion, photochemical oxidation and cumulative energy demand) and less impacting for the other three (acidification, eutrophication and global warming). Production of composting bin and gaseous emissions are the main responsible for the HC impacts, whereas for IC the main contributions come from collection and transportation of organic waste, electricity consumption, dumped waste and VOCs emission. These results suggest that HC may be an interesting alternative or complement to IC in low density areas of population.

Determination of the energy and environmental burdens associated with the biological treatment of source-separated Municipal Solid Wastes

“…including leftovers of raw fruits and vegetables, food scraps and raw fish or meat and other similar wastes) have also been studied and compared to full-scale plants. Complete details of this study can be found in Martínez-Blanco et al 25 HC was performed in a composting bin (70 ×70 ×103 cm) placed outdoors in the Escola d'Enginyeria of the Universitat Autònoma de Barcelona (Bellaterra, Spain).…”

“…A specific methodology was developed to calculate gaseous emissions from the composting process 25,28,29 and from biofilters 30 . In brief, airflow velocity and ammonia, nitrous oxide, methane and VOC concentrations on the surface of the composting pile, composting bin or the biofilter were simultaneously measured on the material surface of the composter in order to calculate the gas outlet emission rate (mg/s).…”

“…29 In open facilities (CCW, TW and HC), emissions were evaluated on the surface of the composting windrows. 25,29 Ammonia emissions are important due to its environmental impact as an atmospheric contaminant, but also due to the possible loss of nitrogen in the final compost and the impact that this phenomenon produces on the use of chemical fertilizers. Since in all plants the waste treated (OFMSW) has the same organic characteristics, the final nitrogen content P r e -p r i n t in the compost could be related to the treatment technology used.…”

Eco-Efficiency Assessment and Food Security Potential of Home Gardening: A Case Study in Padua, Italy

“…LCI data regarding material extraction, processing, transportation and electricity generation were obtained from the ecoinvent database 3.0 [70], while literature data were used for compost production [61] (background data). When background data was employed, the datasets were adapted to the geographical context of the case study of Padua (Italy), thereby indicating the consumption of Italian resources (e.g., natural gas, electricity, water) and of materials produced in their origin markets.…”

Avaliação de novas práticas de compostagem em pequena escala com aproveitamento energético

“…Contudo, questões de escala são relevantes, como discutido por Martínez-Blanco et al (2010), mediante a análise do ciclo de vida, que evidencia as vantagens ambientais da compostagem em pequena escala em comparação à de escala industrial, pois, mesmo predominantemente aeróbica, a compostagem pode ser fonte de CH 4 , NH 3 , NO 3 , SO 2 e N 2 O.…”