College of Environmental Science and Engineering, Qingdao University, Qingdao, China.
College of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, China.
Bioresour Technol. 2024 Dec;413:131532. doi: 10.1016/j.biortech.2024.131532. Epub 2024 Sep 26.
To overcome the issues of limited carbon source and high sludge production in partial denitrification/anammox (PD/A) process, the effects of mixed liquor suspended solids (MLSS) and carbon/nitrogen ratio (C/N) on PD/A were investigated through parallel experiments. Nitrogen removal efficiencies decreased significantly when C/N was reduced (1.5 → 0.75). When MLSS was doubled, the nitrogen removal efficiencies in the two parallel reactors increased from 75.3 %, 72.9 % to 86.9 %, 89.7 %, respectively, and sludge yields decreased obviously. Combining with in-situ test, it was speculated when MLSS increased, fermentation was enhanced, providing substrate for partial denitrification. Thauera, involved in partial denitrification, decreased obviously with reduced C/N, but increased from 9.93 % to 38.16 % when MLSS doubled, which could promote the PD/A process. Terrimonas and Ignavibacterium (fermentative bacteria) increased from 1.26 %, 5.22 % to 6.62 %, 6.30 %, respectively. These results proved that increasing MLSS under low C/N ratios promoted fermentation in PD/A system, facilitating efficient nitrogen removal and sludge reduction.
为了克服部分反硝化/厌氧氨氧化（PD/A）工艺中碳源有限和污泥产量高的问题，通过平行实验研究了混合液悬浮固体（MLSS）和碳氮比（C/N）对 PD/A 的影响。当 C/N 降低（从 1.5 降至 0.75）时，氮去除效率显著下降。当 MLSS 增加一倍时，两个平行反应器中的氮去除效率从 75.3%、72.9%分别增加到 86.9%、89.7%，污泥产量明显下降。结合原位测试，推测当 MLSS 增加时，发酵作用增强，为部分反硝化提供了基质。参与部分反硝化的 Thauera 随着 C/N 的降低而明显减少，但当 MLSS 增加一倍时，从 9.93%增加到 38.16%，这可以促进 PD/A 工艺。发酵细菌 Terrimonas 和 Ignavibacterium 分别从 1.26%、5.22%增加到 6.62%、6.30%。这些结果证明，在低 C/N 比下增加 MLSS 可以促进 PD/A 系统中的发酵，有利于高效脱氮和减少污泥产量。
