Evaluation of the anaerobic degradability of food waste collection bags made of paper and bioplastic

In Italy, the organic fraction is the most relevant among all the separately collected materials in the municipal solid waste. This project aims to analyse the environmental performances of the organic waste treatment chain, with a focus on the type of bags used for the collection. Currently, bioplastic bags are largely predominant in Italy, while paper bags account for a very small amount. In this research, the degradation potential and the corresponding biomethane production of bioplastic and paper bags were evaluated at the laboratory level, by means of BMP (Biochemical Methane Potential) tests. Then, to better simulate the operating conditions of full-scale digesters, semi-continuous co-digestion tests with the food waste were performed. The results of BMP tests under thermophilic conditions indicated a good degradability of both bioplastic and paper bags. On the contrary, the semi-continuous co-digestion tests showed significant differences between the two materials, with a limited degradation of bioplastic bags and a high compatibility of paper bags with the anaerobic digestion.