Print Email Facebook Twitter Microbial population dynamics during long-term sludge adaptation of thermophilic and mesophilic sequencing batch digesters treating sewage fine sieved fraction at varying organic loading rates Title Microbial population dynamics during long-term sludge adaptation of thermophilic and mesophilic sequencing batch digesters treating sewage fine sieved fraction at varying organic loading rates Author Tao, Y. De Kreuk, M.K. Zandvoort, M.H. Van Lier, J.B. Faculty Civil Engineering and Geosciences Department Water Management Date 2015-10-21 Abstract Background In this research, the feasibility of, and population dynamics in, one-step anaerobic sequencing batch reactor systems treating the fine sieved fraction (FSF) from raw municipal wastewater was studied under thermophilic (55 °C) and mesophilic (35 °C) conditions. FSF was sequestered from raw municipal wastewater, in the Netherlands, using a rotating belt filter (mesh size 350 micron). FSF is a heterogeneous substrate that mainly consists of fibres originating from toilet paper and thus contains a high cellulosic fraction (60–80 % of total solids content), regarded as an energy-rich material. Results Results of the 656-day fed-batch operation clearly showed that thermophilic digestion was more stable, applying high organic loading rates (OLR) up to 22 kg COD/(m 3 day). In contrast, the mesophilic digester already failed applying an OLR of 5.5 kg COD/(m 3 day), indicated by a drop in pH and increase in volatile fatty acids (VFAs). The observed viscosity values of the mesophilic sludge were more than tenfold higher than the thermophilic sludge. 454-pyrosequencing of eight mesophilic and eight thermophilic biomass samples revealed that Bacteroides and aceticlastic methanogen Methanosaeta were the dominant genera in the mesophilic digester, whereas OP9 lineages, Clostridium and the hydrogenotrophic methanogen Methanothermobacter dominated the thermophilic one. Conclusions Our study suggests that applying thermophilic conditions for FSF digestion would result in a higher biogas production rate and/or a smaller required reactor volume, comparing to mesophilic conditions. Subject anaerobic digestionfine sieved fraction (FSF)cellulosevolatile fatty acids (VFAs)adaptationmicrobial communityOA-Fund TU Delft To reference this document use: http://resolver.tudelft.nl/uuid:2ee51641-40c7-48a9-83a6-4f50f4340669 Publisher BioMed Central ISSN 1754-6834 Source https://doi.org/10.1186/s13068-015-0355-3 Source Biotechnology for Biofuels, 8, 2015 Part of collection Institutional Repository Document type journal article Rights © 2015 The Author(s) Files PDF 320944.pdf 3.08 MB Close viewer /islandora/object/uuid:2ee51641-40c7-48a9-83a6-4f50f4340669/datastream/OBJ/view