2009 Volume 71 Issue 3 Pages 3_55-3_62
A simulated pilot experiment on household solid waste treated directly with biodegradable plastics was conducted by a thermophilic dry anaerobic digestion process to determine the fermentation characteristics of biodegradable plastics. A batch experiment showed that 7∼8 weeks was needed for complete decomposition of biodegradable plastics that are polylactide (PLA)-based. Rates of removal of PLA used in rubbish collection bags, fresh-keeping bags and drinking cups were about 37%, 80% and 52%, respectively. A continuous experiment using four reactors (R1, R2, R3 and R4) was also conducted with differences of carbon to nitrogen (C/N) ratios and different input amounts of PLA. The average PLA removal efficiencies of R2 and R3 at an organic loading rate of 6.6gVS/kg-sludge·day were approximately 49% and 33%, respectively.