Optimum Organic Loading Rates (OLR) for Food Waste Anaerobic Digestion: Study Case Universitas Indonesia

Abstract

Indonesia currently has a waste generation problem arising from the fact that sixty percent of the waste it produces is organic waste (OW). The scope for anaerobic digestion (AD) of OW has not yet been optimized, with many reactors not functioning properly. The purpose of this study is to determine the suitability of food waste with an organic loading rate (OLR) of 8–14 kgVS/m3day to produce the highest volatile solids destruction (VSD) and methane. A semi-continuous pilot-scale dry AD of 0.5 m3 was run for 134 days in mesophilic conditions. The results showed that the feedstock was suitable for dry AD due to the high total solids (TS) (23.2–27.1%) and organic content (volatile solids of 90–95% TS). Meanwhile, the optimum OLR was 10 kgVS/m3day with a VSD of 92.2% and a methane yield of 127 LCH4/grVSday. In addition, OLR 10 kgVS/m3day had the highest stability, as shown by the pH value of 6.52 and ammonia concentration of 848 mg/l. The VSD values fell with respect to the OLRs of 12 kgVS/m3day and OLR 14 kgVS/m3day, to 90.42% and 86.73%, respectively.

Keywords

• biogas
• inhibitor
• municipal waste
• renewable energy