Abstract
Ammonia is the major inhibitor of anaerobic digestion (AD) process in biogas plants. In the current study, the bioaugmentation of the ammonia tolerant SAO co-culture (i.e. Clostridium ultunense spp. nov. in association with Methanoculleus spp. strain MAB1) in a mesophilic up-flow anaerobic sludge blanket (UASB) reactor subjected to high ammonia loads was tested. The co-cultivation in fed-batch reactors of a fast-growing hydrogenotrophic methanogen (i.e. Methanoculleus bourgensis MS2T) with the SAO co-culture was also investigated. Results demonstrated that bioaugmentation of SAO co-culture in a UASB reactor was not possible most likely due to the slow maximum growth rate (μmax=0.007h-1) of the culture caused by the methanogenic partner. The addition of M. bourgensis to SAO led to 42% higher growth rate (μmax=0.01h-1) in fed-batch reactors. This indicates that methanogens were the slowest partners of the SAO co-culture and therefore were the limiting factor during bioaugmentation in the UASB reactor. © 2013 Elsevier Ltd.
Original language | English |
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Journal | Bioresource Technology |
Volume | 146 |
Pages (from-to) | 57-62 |
ISSN | 0960-8524 |
DOIs | |
Publication status | Published - 2013 |
Keywords
- Ammonia
- Batch reactors
- Cultivation
- Methanogens
- Volatile fatty acids
- Anaerobic digestion