The environmental impacts of five waste management scenarios for polylactic acid (PLA)-based bioplastics and food waste were quantified using life cycle assessment. Laboratory experiments have demonstrated the potential for a pretreatment process to accelerate the degradation of bioplastics and were modeled in two of the five scenarios assessed. The five scenarios analyzed in this study were: (1a) Anaerobic digestion (1b) Anaerobic digestion with pretreatment; (2a) Compost; (2a) Compost with pretreatment; (3) Landfill. Results suggested that food waste and pretreated bioplastics disposed of with an anaerobic digester offers life cycle and environmental net total benefits (environmental advantages/offsets) in several areas: ecotoxicity (−81.38 CTUe), eutrophication (0 kg N eq), cumulative energy demand (−1.79 MJ), global warming potential (0.19 kg CO2), and human health non-carcinogenic (−2.52 CTuh). Normalized results across all impact categories show that anaerobically digesting food waste and bioplastics offer the most offsets for ecotoxicity, eutrophication, cumulative energy demand and non-carcinogenic. Implications from this study can lead to nutrient and energy recovery from an anaerobic digester that can diversify the types of fertilizers and decrease landfill waste while decreasing dependency on non-renewable technologies. Thus, using anaerobic digestion to manage bioplastics and food waste should be further explored as a viable and sustainable solution for waste management.
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This study was financially supported by the NSF CBET Award No. 1066658/1246547/1553126. S.R.H. was supported by an IGERT-SUN fellowship funded by the National Science Foundation (Award 1144616) and the Environmental Research and Education Foundation.
The following are available online at https://www.mdpi.com/article/10.3390/su13126894/s1, Table S1. Anaerobic digestion of food waste and bioplastics (scenario 1a) inventory data for waste treatment options, Table S2. Anaerobic digestion of food waste and pretreated bioplastics (scenario 1b) inventory data for waste treatment options. Table S3. Compost of food waste and bioplastics (scenario 2a) inventory data for waste treatment options. Table S4. Compost of food waste and pretreated bioplastic (scenario 2b) inventory data for waste treatment options.
The above materials are also available for download as the additional file listed at the end of this record.
Hobbs, Shakira R.; Harris, Tyler M.; Barr, William J.; and Landis, Amy E., "Life Cycle Assessment of Bioplastics and Food Waste Disposal Methods" (2021). Civil Engineering Faculty Publications. 21.