Biodegradation of bioplastics under aerobic and anaerobic aqueous conditions: Kinetics, carbon fate and particle size effect

Abstract

The biodegradation of PHB, PHBV, PBS, PBAT, PCL, PLA, and a PLA-PCL blend was systematically compared under aerobic and anaerobic aqueous conditions assessing biodegradation kinetics, extent, carbon fate and particle size influence (in the range of 100–1000 µm). Under standard test conditions, PHB and PBHV were biodegraded anaerobically (83.9±1.3% and 81.2±1.7%, respectively) in 77 days or aerobically (83.0±1.6% and 87.4±7.5%) in 117 days, while PCL was only biodegraded (77.6±2.4%) aerobically in 177 days. Apparent biomass growth accounted for up to 30.5% of the total initial carbon depending on the bioplastic and environment. Maximum aerobic and anaerobic biodegradation rates were improved up to 331 and 405%, respectively, at the lowest particle size tested (100–250 µm). This study highlights the usefulness of a more detailed analysis of biodegradation kinetics and carbon fate to improve both the development and testing of biodegradable materials/products in the context of a circular bioeconomy.