Anaerobic degradation of glycolysis products of polyethylene terephthalate

Abstract

Waste decomposition through anaerobic digestion has been studied in several ways the u the present. Among these wastes, plastics currently cause the most environmental pollution, so research using anaerobic digestion of plastics is also in progress. In this study, bis(2-hydroxy ethylterephthalate) (BHET), a monomer of polyethylene terephthalate (PET), which accounts for a large portion of plastic waste, was decomposed through anaerobic digestion in a mesophilic condition using a 2.0 L bottle reactor. As a feed, 8.2 COD g/L of BHET was added, and after consumption, all BHET has added to 8.2 COD g/L BHET again. A small amount of biogas (CH4, CO2, H2) was obtained, and 30.87 COD g/L of BHET was decomposed by acidogenesis fermentation sludge in 40 days. The production of terephthalic acid (TPA) was confirmed, suggesting that BHET was decomposed through anaerobic digestion. In addition, in the case of TPA, it can be decomposed into acetic acid, and in this experiment, the production of 17.02 COD g/L of acetic acid was also confirmed. The changes in the initial and cluster samples after 30 days were confirmed through genus-level cluster analysis. Among them, strains with high similarity to strains using an aromatic compound called Desulfoscipio geothermicus as a carbon source were identified. It was confirmed that the Hydrogenispora family with the same family as this strain appeared, and it can be predicted that similar strains can degrade BHET. As a result, through this experiment, the decomposition process of PET was investigated, the productivity of biogas was compared, and the decomposition process of PET was confirmed through GC×GC/TOF-MS analysis. In the case of the anaerobic degradation pathway of PET, it has not yet been precisely known, but the PET anaerobic degradation pathway has been confirmed.