Effects of turning aeration and the initial carbon/nitrogen ratio on the biodegradation of polylactic acid under controlled conditions

In this study, we assessed how turning aeration and the initial carbon/nitrogen (C/N) ratio impact PLA biodegradation. The study was carried out under controlled composting conditions, over 180 days, with the aim of decreasing the biodegradation time of the PLA. Apple pomace, rice husk, grape pomace compost, and PLA were used as substrates in the composting process. The experiments were conducted using three types of turning aeration: without turning, one turn per week, and two turns per week. Three initial C/N ratios were used: 20, 30, and 40. A stepwise temperature ramp was designed and implemented to simulate industrial composting conditions, which influence microbial activity and thus the rate of decomposition of substrates, including PLA. The data showed behavior; hence, a nonlinear regression model based on the logistic growth equation was used to predict the PLA biodegradation at the end of the composting process. The results showed that two turns per week with an initial C/N ratio of 30 or 40 led to a 90 % biodegradation of the PLA in 130 days. This degradation was verified by Fourier-Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM).PMID:38642680 | DOI:10.1016/j.ijbiomac.2024.131689

Source: International Journal of Biological Macromolecules - April 20, 2024 Category: Biochemistry Authors: Yvan Baldera-Moreno Camila Hern ández Aris Vargas Alejandro Rojas-Palma Rodrigo Morales-Vera Rodrigo Andler Source Type: research