Author(s):
Fernandes, Miguel ângelo Cavaleiro ; Salvador, Andreia Filipa Ferreira ; Madalena, Daniel Alexandre Silva ; Vicente, A. A.
Date: 2025
Persistent ID: https://hdl.handle.net/1822/94564
Origin: RepositóriUM - Universidade do Minho
Project/scholarship:
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB%2F04469%2F2020/PT;
Subject(s): Central composite rotational design; Polybutylene adipate terephthalate; Polyhydroxybutyrate; Prediction model; Soil biodegradation
Description
Available online 8 January 2025
The massive use of plastics in various applications, particularly packaging, generates enormous amounts of plastic waste that can be found almost everywhere, including in soil. This represents a serious environmental pollution issue since the biodegradability in soils can take several years, depending on the microbial composition, the physical and chemical characteristics of plastics, and other relevant environmental factors such as the soil temperature, the soil moisture holding capacity (MHC), and the carbon:nitrogen (C/N) ratio. In this work, we evaluated the importance of these soil physical-chemical parameters on the biodegradation of a plastic film composed of PHB/PBAT. A design-of-experiments methodology, namely the Central Composite Rotational Design (CCRD) was used to determine the effects of these parameters in the biodegradation of the films in soil. The carbon dioxide evolution was followed for 6 months following the guidelines of the ASTM D5988 (2018). The results showed that the most important factor was the temperature. Higher temperatures ( 37 °C) accelerated biodegradation while the adding of nitrogen (aqueous solution of ammonium chloride) had no impact on this process, probably because the C/N ratio pre-existing in the soil was suitable to guarantee microbial activity. Although a MHC between 80% and 100% is recommended by international standards, 60% MHC produced similar results. According to the methodology, the best combination possible includes a temperature of 37 °C and a MHC ranging from 60 to 100%.
This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/ 04469/2020 unit, and by LABBELS – Associate Laboratory in Biotech nology, Bioengineering and Microelectromechanical Systems, LA/P/ 0029/2020. Furthermore, this study was also supported by BioTecNorte operation (NORTE-01–0145- FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. The fellowship is supported by a Doctoral advanced training (call NORTE-69–2015–15) funded by the European Social Fund under the scope of Norte2020 - Programa Oper acional Regional do Norte. Finally, by the doctoral grant PD/BD/ 146195/2019 and the grant COVID/BD/153308/2023.
info:eu-repo/semantics/publishedVersion