The Biodigestibility Potential of Bioplastics in Anaerobic Digestion

Abstract

Bioplastics, despite its advantages, still possesses several problems; one of it is the end disposal or recovery after use. The best way of disposing of bioplastics has not been established yet. In present work, polylactic acid, polybutylene succinate, polyhydroxy butyrate, and cellulose acetate bioplastic were tested for their potential as a substrate for production of hydrogen and volatile fatty acids through anaerobic digestion. The effect of 0.1M sodium acetate buffer and supplementation, as well as size reduction on the production of hydrogen and VFAs from bioplastics, were studied. The results showed that size-reduced cellulose acetate could produce the highest hydrogen and VFAs accumulation among the tested bioplastic which was about 6.8 mL/g VS for hydrogen and 0.312 g VFA/g VS. The addition of buffer and supplementation could improve the production of hydrogen and VFAs in PLA and cellulose granules but inhibited the production in size reduced PLA and cellulose acetate. Meanwhile, size reduction showed to be significant for the production of VFAs for all bioplastics P-value of 0.001. In conclusion, size reduced bioplastics have potential to be used as a substrate in VFAs and hydrogen production if buffer and amount of supplementation is tailored depending on the desired final product.