Anaerobic digestion and aerobic composting of rigid biopolymers in bio-waste treatment: fate and effects on the final compost. (May 2022)

• Record Type: Journal Article
• Authors: Bandini, Francesca; Taskin, Eren; Vaccari, Filippo; Soldano, Mariangela; Piccinini, Sergio; Frache, Alberto; Remelli, Sara; Menta, Cristina; Sandro Cocconcelli, Pier; Puglisi, Edoardo
• Is Part Of: Bioresource technology. Volume 351(2022)
• Publication Date: 2022-05
• Subjects: Ecotoxicity -- Biodegradation -- Compostability -- Polylactic acid -- Biochemical Methane Potential; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2022.126934
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Compostable certified bioplastics were not compatible with the bio-waste treatment. Bioplastics' residues < 2 mm were found in the final composts. Polylactic acid lowered compost pH and negatively affected the germination index. Further research on the effect of starch-based bioplastics on earthworms is needed. Compost from bio-waste treatment may be a source of environmental contamination. Abstract: Bioplastics may be collected in the bio-waste treatment, which is often composed of anaerobic digestion and subsequent aerobic composting of the digestates. The aim of this study was to evaluate the degradability of polylactic acid (PLA) and starch-based bioplastics (SBB) spoons under industrial conditions. Biomethane potential (BMP) was measured and biogas production was monitored, while the quality of composts was assessed by phytotoxicity and ecotoxicity tests. The bioplastics disintegration resulted in 65.1 ± 4.6 % for PLA and ≤ 65.0 ± 7.4 % for SBB, not achieving the target set by UNI EN 13, 432 standard, and several residues were found in compost. Phytotoxicity tests on seeds reported the lowest Germination Index for PLA elutriate, whereas a potential negative effect of SBB on soil fauna was detected. Further investigation is needed to assess the fate of these ever-growing materials under industrial conditions, and also evaluate the effects of residues in compost.