Department of Chemical and Biochemical Engineering, Technical University of Denmark, Kgs, Lyngby, DK-2800, Denmark.
Department of Chemical and Biochemical Engineering, Technical University of Denmark, Kgs, Lyngby, DK-2800, Denmark.
Chemosphere. 2022 Jun;296:133987. doi: 10.1016/j.chemosphere.2022.133987. Epub 2022 Feb 14.
Two thermophilic trickle bed reactors (TBRs) were packed with different packing densities with polyurethane foam (PUF) and their performance under different retention times were evaluated during ex-situ biogas upgrading process. The results showed that the TBR more tightly packed i.e. containing more layers of PUF achieved higher H utilization efficiency (>99%) and thus, higher methane content (>95%) in the output gas. The tightly packed micro-porous PUF enhanced biofilm immobilization, gas-liquid mass transfer and biomethanation efficiency. Moreover, applying a continuous high-rate nutrient trickling could lead to liquid overflow resulting in formation of non-homogenous biofilm and severe deduction of biomethanation efficiency. High-throughput 16S rRNA gene sequencing revealed that the liquid media were predominated by hydrogenotrophic methanogens. Moreover, members of Peptococcaceae family and uncultured members of Clostridia class were identified as the most abundant species in the biofilm. The proliferation of hydrogenotrophic methanogens together with syntrophic bacteria showed that H addition resulted in altering the microbial community in biogas upgrading process.
两个嗜热滴流床反应器（TBR）分别采用不同的堆积密度填充聚氨酯泡沫（PUF），并在不同停留时间下评估其在沼气升级过程中的性能。结果表明，堆积更紧密的 TBR 即包含更多层的 PUF 实现了更高的 H 利用率（>99%），从而在输出气体中实现了更高的甲烷含量（>95%）。紧密堆积的微孔 PUF 增强了生物膜固定化、气液传质和生物甲烷化效率。此外，应用连续高负荷养分滴流可能导致液体溢出，从而形成非均匀生物膜并严重降低生物甲烷化效率。高通量 16S rRNA 基因测序表明，液体培养基主要由氢营养型产甲烷菌组成。此外，发现肠球菌科（Peptococcaceae）的成员和未培养的梭菌纲（Clostridia）成员是生物膜中最丰富的物种。氢营养型产甲烷菌与共栖细菌的增殖表明，H 的添加改变了沼气升级过程中的微生物群落。
