Abstract
Two strategies exist for seeding low-temperature anaerobic reactors: the use of specialist psychrophilic biomass or mesophilic bioreactor sludge acclimated to low temperature. We sought to determine the low-temperature limitation of anaerobic sludge from a bioreactor acclimated to UK temperatures (<15 °C). Anaerobic incubation tests using low-strength real domestic wastewater (DWW) and various alternative soluble COD sources were conducted at 4, 8 and 15 °C; methanogenesis and acidogenesis were monitored separately. Production of methane and acetate was observed; decreasing temperature resulted in decreased yields and increased 'start-up' times. At 4 °C methanogenesis not hydrolysis/acidogenesis was rate-limiting. The final methane yields at 4 °C were less than 35% of the theoretical potential whilst at 8 and 15 °C more than 75 and 100% of the theoretical yield was achieved respectively. We propose that the lower temperature limit for DWW treatment with anaerobic bioreactor sludge lies between 8 and 4 °C and that 8 °C is the threshold for reliable operation.
Original language | English |
---|---|
Pages (from-to) | 1004-1013 |
Number of pages | 10 |
Journal | Water Science and Technology |
Volume | 69 |
Issue number | 5 |
Early online date | 30 Dec 2013 |
DOIs | |
Publication status | Published - Mar 2014 |
Externally published | Yes |
Keywords
- Anaerobic treatment
- Domestic wastewater
- Mesophilic inoculum
- Psychrophilic