Certified Compostable Products and Sustainable Food Waste Management via Laboratory-Level Simulation Anaerobic Digestion and Postdigestion Composting

Abstract

Certified compostable products are designed for use in organic waste management. In practical scenarios, these products can be used as food packaging and food service ware, and they can also be utilized in food waste treatment facilities. In this study, we investigated the degradation of certified compostable plastic bags and coated paper in a laboratory-scale food waste treatment system. Anaerobic digestion (AD) systems operate stably when the addition of certified compostable products accounts for less than 15% of the total feedstock mass. The methane yield of the compostable products during AD was 141− 284 mL/g-VS, varying with the amount of the compostable product added. Cellulose in coated paper achieves resource recovery via methane production and plays a role in regulating the feed quality of ADs. In the subsequent postdigestion composting step, the residual certified compostable plastic in the digestate fully biodegraded within 80 days. The disintegration percentage and mineralization percentage for the post-AD plastic were 88.50 and 77.65%, respectively. Additionally, the composting results indicate that compostable plastic biodegradation is enhanced after AD. This paper highlights the feasibility of using certified compostable plastic bags and coated paper for the cotreatment of food waste through AD and postdigestion composting processes, providing a new method for resourcing paper and plastic products that has reduced direct recycling value due to food waste contamination.