Validation of an Automated Multiunit Composting System

Biodegradable packaging has high potential to help solve the crisis of non-biodegradable plastic waste causing an increase in the footprint of landfills. However, more research needs to be executed to develop a larger assortment of biodegradable plastics for numerous applications and to make them more economical to manufacture. This paper discusses the design and validation of an automated composting system (AMUCS) that fits the requirements of the American Society for Testing and Materials (ASTM) 5338-11 standard. The results of the experiments show that the AMUCS was able to create and maintain the conditions for biodegradation of biodegradable polymers in compost using microcrystalline cellulose. The biodegradation caused by the composting environment was observed visually with the naked eye and on the micro scale with an environmental scanning electron microscope. The magnitude of biodegradation was measured by calculating the carbon metabolized from the samples. The carbon metabolized from the three compost replicates was consistent and linear, and there was only an 8 % difference between the non-biodegradable low density polyethylene and the compost. For the biodegradation study according to ASTM D 5338-11, the experiment was validated with the use of cellulose as a reference material. Under controlled composting conditions, the mineralization of microcrystalline cellulose yielded 72.05 %, which is slightly higher than the 70 % mineralization requirement.