Life cycle assessment of biowaste and green waste composting systems: A review of applications and implementation challenges

E R Oviedo-Ocaña; C Abendroth; I C Domínguez; A Sánchez; C Dornack

doi:10.1016/j.wasman.2023.09.004

Life cycle assessment of biowaste and green waste composting systems: A review of applications and implementation challenges

Waste Manag. 2023 Sep 11:171:350-364. doi: 10.1016/j.wasman.2023.09.004. Online ahead of print.

Authors

E R Oviedo-Ocaña¹, C Abendroth², I C Domínguez¹, A Sánchez³, C Dornack⁴

Affiliations

¹ Universidad Industrial de Santander, Facultad de Ingenierías Fisicomecánicas, Grupo de Investigación en Recurso Hídrico y Saneamiento Ambiental - GPH, Carrera 27 Calle 9 Ciudad Universitaria Bucaramanga, Colombia.
² Technische Universität Dresden, Institute of Waste Management and Circular Economy, Pratzschwitzer Str. 15. 01796 Pirna, Germany; Brandenburg Technical University Cottbus-Senftenberg, Faculty of Environment and Natural Sciences, Lehrgebäude 4 A R2.25, Siemens-Halske-Ring 8 03046 Cottbus, Germany.
³ Universitat Autònoma de Barcelona, Department of Chemical Engineering, Composting Research Group, 08193, Barcelona, Bellaterra, Spain. Electronic address: antoni.sanchez@uab.cat.
⁴ Technische Universität Dresden, Institute of Waste Management and Circular Economy, Pratzschwitzer Str. 15. 01796 Pirna, Germany.

PMID: 37708800
DOI: 10.1016/j.wasman.2023.09.004

Abstract

Composting is one of the most widely applied methods for recycling organic waste. This process has been proposed as one option that facilitates the reincorporation of materials into the production cycle. However, composting also generates environmental impacts. Life Cycle Assessment (LCA) is the most common approach to evaluate the environmental impacts of a process at different system stages. Nevertheless, applying LCA in composting facilities is challenging due to the extensive information required, the lack of standardization on the initial assumptions, the definition of system boundaries, and the high diversity of existing composting technologies. This paper systematically reviews LCA studies in biowaste and/or green waste composting. The study highlights the challenges that should be met in order to improving the application of LCA to evaluate the environmental impacts of this type or waste treatment strategy. The review protocol used identified 456 papers published between 2010 and 2022. After the screening, 56 papers were selected, read, and thoroughly analyzed. The results show that: i) about 68% of the studies aimed to compare composting with other solid waste management options; ii) there was a wide diversity among the impact categories considered, which predominantly included climate change and ozone depletion; iii) there was no consensus on the functional unit or the system boundaries; iv) the main gaseous emissions studied were ammonia, methane, and nitrogen oxide, which were generally determined by emission factors; v) the avoided environmental impacts associated with the end-product quality and its application as an organic amendment or soil improver were ignored. This work demonstrates the complexity of conducting credible and valid composting LCA studies and proposes seven recommendations for improving the application of this assessment methodology to analyze this waste management alternative.

Keywords: Biowaste; Composting; Environmental impact; Green waste; Life Cycle Assessment.