NEWS

WASTE-TO-BAG is a project that aims to produce biodegradable bags for the collection of organic waste (OFMSW), using PHA biopolymers (polyhydroxyalkanoates), capable of degrading completely in the composting plants currently in use. PHAs are thermoplastic polyesters synthesized by bacteria in particular conditions, they are metabolized by microorganisms present in soil, water and the marine environment and are converted into simpler substances such as water, carbon dioxide and biomass; they have the peculiar characteristic of not generating microplastics unlike other compostable materials. PHAs composted together with organic materials based on lignocellulose and natural fibers produce a high-quality compost that can be used to improve soil fertility.
The project initially envisages the use of commercial PHAs, potentially supplemented with biodegradable waste materials from the Tuscany Region, to reduce costs and improve compostability.
The materials will be transformed into tubular film through bubble extrusion, then converted into bags. The quality of the bags obtained will be measured, from an environmental performance point of view through anaerobic biodegradation tests and compostability tests, while from the physical properties point of view the mechanical properties will be measured in order to obtain values comparable with the current bags based on biodegradable resin.
However, current sourcing of PHAs from foreign suppliers entails high costs and environmental impacts.
To overcome this limitation, WASTE-TO-BAG intends to develop a local PHA production process using the same OFMSW as a raw material. The project involves the inoculation of OFMSW with specific microorganisms coming from anaerobic digestion plants to obtain volatile fatty acids (VFAs), which will then be transformed into PHA by selected bacterial strains. This virtuous cycle transforms a waste into a useful resource, promoting the circular economy.
Several phases of experimentation are planned, from the laboratory scale up to a 100L prototype bioreactor, with attention to the seasonality of the OFMSW. In parallel, methods of extraction and purification of PHA for future industrial applications will be tested.
WASTE-TO-BAG therefore represents an innovative and sustainable initiative that integrates science, environment and local economic development, promoting the health of the planet and the valorization of organic waste.