Know more

Elucidate the biodegradation mechanisms of biobased biodegradable food films and packaging in methanization

Oil-based plastic food films and packaging are objects that are particularly difficult to sort out and recycle from household waste. Soiled and damaged, they end their life in incineration or in landfills where they generate micro- and nano-plastics that in the long term represent a significant environmental and health risk.

Today many alternative materials are biodegradable. Sorted out at home, they can be degraded along with the fermentable fraction of household waste in industrial or domestic composting conditions. However, little is known about their behavior in anaerobic digestion systems.

In this context, this thesis project aims to elucidate the biodegradation mechanisms of commercial biodegradable food films and packaging in anaerobic digestion conditions. The studied materials are commercial plastics based on starch and PBAT (Polybutylene adipate terephthalate) and innovative materials derived from renewable but non-food resources developed at INRAE's UMR IATE and based on PHA (polyhydroxyalkanoates) and lignocellulosic fibers. The deterioration of these materials during anaerobic digestion will be monitored over time by microscopy and physical techniques (MEB, thermogravimetry, spectrometry) and by the development of non-destructive method (NMR, FT-IR). A biofilm culture chamber will also be developed to study the microbial colonization of materials and isolate strains capable of degrading polymers. Knowledge of these mechanisms is an essential prerequisite for the implementation of eco-design approaches integrating both the needs of the stakeholders and the end of life of the products