The increasing use of bioplastics in packaging applications necessitates rigorous evaluation of their fate in real waste management systems. While bioplastics are often marketed as biodegradable, their actual behavior under mesophilic anaerobic digestion (AD) is frequently insufficiently understood and often overestimated in commercial claims. Polylactic acid (PLA), one of the most widely produced bio-based polymers, has been widely characterized under these conditions, but little is known about the metabolomic changes associated with its biodegradation under mesophilic anaerobic conditions. This study investigates the mesophilic AD (37 °C for more than 3 months) of PLA films (2.5 × 2.5 cm) co-digested with the organic fraction of municipal solid waste (OFMSW). Biogas production and energy yield evaluation were assessed for AD, along with chemical parameters and metabolomic analyses. PLA biodegradation, calculated according to ISO 15985:2014, reached values close to 100% after more than 3 months, highlighting a prolonged lag phase under mesophilic AD conditions. The biogas production yielded about 380 Nm3 per t of volatile solids. Metabolomic profiling during AD revealed that the onset of PLA biodegradation, highlighted also by biogas emission, coincides with the appearance of key metabolites associated with PLA hydrolysis. These findings demonstrate that the mesophilic anaerobic co-digestion of PLA films with OFMSW did not cause any inhibition effect on biogas production. The results demonstrate the feasibility of incorporating PLA into existing organic waste treatment systems, thereby supporting both energy recovery and sustainable waste management.
Anaerobic Co-Digestion of Polylactic Acid (PLA) Films with Organic Fraction of Municipal Solid Waste: Biodegradation, Biogas Yields, and Metabolomic Analysis
Montegiove, Nicolò;Puglia, Debora;Pellegrino, Roberto Maria;Dominici, Franco;Calzoni, Eleonora;Pezzolla, Daniela
2026
Abstract
The increasing use of bioplastics in packaging applications necessitates rigorous evaluation of their fate in real waste management systems. While bioplastics are often marketed as biodegradable, their actual behavior under mesophilic anaerobic digestion (AD) is frequently insufficiently understood and often overestimated in commercial claims. Polylactic acid (PLA), one of the most widely produced bio-based polymers, has been widely characterized under these conditions, but little is known about the metabolomic changes associated with its biodegradation under mesophilic anaerobic conditions. This study investigates the mesophilic AD (37 °C for more than 3 months) of PLA films (2.5 × 2.5 cm) co-digested with the organic fraction of municipal solid waste (OFMSW). Biogas production and energy yield evaluation were assessed for AD, along with chemical parameters and metabolomic analyses. PLA biodegradation, calculated according to ISO 15985:2014, reached values close to 100% after more than 3 months, highlighting a prolonged lag phase under mesophilic AD conditions. The biogas production yielded about 380 Nm3 per t of volatile solids. Metabolomic profiling during AD revealed that the onset of PLA biodegradation, highlighted also by biogas emission, coincides with the appearance of key metabolites associated with PLA hydrolysis. These findings demonstrate that the mesophilic anaerobic co-digestion of PLA films with OFMSW did not cause any inhibition effect on biogas production. The results demonstrate the feasibility of incorporating PLA into existing organic waste treatment systems, thereby supporting both energy recovery and sustainable waste management.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
