The performances and stabilities of three laboratory-scale semi-batch anaerobic digesters, operated at 35°C, treating organic fraction of municipal solid waste (OFMSW) and primary sewage sludge (PSS) mixed at various ratios were compared during the start-up period. The OFMSW:PSS ratios in the feeds to the three digesters were 100:0, 80:20, and 60:40 on a total solids (TS) basis and their organic loading rates (OLR) were 5.2 kg VS m−3 d−1, 3.9 kg VS m−3 d−1, and 3.2 kg VS m−3 d−1, respectively. There were no indications of failure in any of the digesters. However, addition of primary sewage sludge significantly decreased the imbalances observed during the start-up and improved the process performance. The best performance in terms of specific gas production rate (SGPR) was obtained with a feedstock having an OFMSW:PSS ratio of 80:20. The use of inoculum from an operating anaerobic digester enabled a quick start-up and the reactors were capable of handling high OLRs from the beginning of the experiment.
No takes yet. Share an insight, caveat, or question.
Demirekler et al. (1998) studied this question.