Effect of propionate-cultured sludge augmentation on methane production from upflow anaerobic sludge blanket systems treating fresh landfill leachate

This research investigates the effect of propionate-cultured sludge augmentation on methane (CH4) pro-duction from upflow anaerobic sludge blanket systems (UASB) treating fresh landfill leachate. In the study, both UASB reactors (UASB 1 and UASB 2) contained acclimatized seed sludge, and UASB 2 was aug-mented with propionate-cultured sludge. The organic loading rate (OLR) was varied between 120.6, 84.4, 48.2, and 12.0 gCOD/L center dot d. The experimental results indicated that the optimal OLR of UASB 1 (non -aug-mentation) was 48.2 gCOD/L center dot d, achieving the CH4 production of 4019 mL/d. Meanwhile, the optimal OLR of UASB 2 was 12.0 gCOD/L center dot d, achieving the CH4 yield of 6299 mL/d. The dominant bacterial com-munity in the propionate-cultured sludge included the genera Methanothrix, Methanosaeta, Methanoculleus, Syntrophobacter, Smithella, Pelotomamulum, which are the VFA-degrading bacteria and methanogens responsible for unblocking the CH4 pathway bottleneck. Essentially, the novelty of this research lies in the use of propionate-cultured sludge to augment the UASB reactor in order to enhance CH4 production from fresh landfill leachate.

Automated summary

This research investigates the use of propionate-cultured sludge to enhance methane production from upflow anaerobic sludge blanket systems (UASB) treating fresh landfill leachate. The experimental results showed that the optimal OLR for UASB 1 without augmentation was 48.2 gCOD/L dot d, achieving a CH4 production of 4019 mL/d. On the other hand, the optimal OLR for UASB 2 with propionate-cultured sludge augmentation was 12.0 gCOD/L dot d, achieving a CH4 yield of 6299 mL/d.