Abstract
This study aimed to develop an in-situ sludge pretreatment method by increasing the temperature from thermophilic to extreme thermophilic condition in a single-stage anaerobic digester. The results revealed that a stable performance was obtained within the temperature range of 55–65 °C, and the maximum methane yield of 208.51 ± 13.66 mL/g VS was obtained at 65 °C. Moreover, the maximum extent of hydrolysis (33%) and acidification (27.1%) was also observed at 65 °C. However, further increase of temperature to 70 °C did not improve the organic conversion efficiency. Microbial community analysis revealed that Coprothermobacter, highly related to acetate oxidisers, appeared to be the abundant bacterial group at higher temperature. A progressive shift in methanogenic members from Methanosarcina to Methanothermobacter was observed upon increasing the temperature. This work demonstrated single-stage sludge digestion system can be successfully established at high temperature (65 °C) with stable performance, which can eliminate the need of conventional thermophilic pretreatment step.
| Original language | English |
|---|---|
| Pages (from-to) | 102-108 |
| Number of pages | 7 |
| Journal | Bioresource Technology |
| Volume | 238 |
| DOIs | |
| State | Published - 2017 |
| Externally published | Yes |
Keywords
- Methane production
- Microbial community
- Single-stage sludge digestion
- Thermophilic temperature gradient
