The growing problem of waste bioplastics disposal, and a way to tackle it

Biodegradable plastics will grow significantly in the coming years thanks to their potential for renewability and circularity, particularly in certain European countries. Despite being a niche, their disposal is already emerging as a challenge. Insufficient public awareness is a partial cause, with people being unaware or confused on how to deal with them. Other problems are inherent to the way organic waste treatment plants work. There is indeed a stark contrast between standard biodegradability tests and actual conditions at treatment facilities, often dismissed or ascribed to the negligence of plant operators. If bioplastics are really to be deployed on a large scale, a joint technological effort is essential to properly manage their end-of-life. This contribution briefly summarises the scenario of bioplastic use in the world, the European legislation on the matter (or lack thereof), and the difficulties that waste management plants face with these materials, with a focus on a reference case - Italy - and with an international perspective. Finally, we explore how hydrothermal treatments are emerging in the scientific literature as a possible solution to some of these problems, as they can solubilise most bioplastics and facilitate their treatment in the most updated organic waste treatment plants, which couple anaerobic digestion and composting.