College of Architecture and Environment, Sichuan University, Chengdu, 610065, China.
School of Environmental and Planning, Liaocheng University, Liaocheng, 252000, China.
Appl Biochem Biotechnol. 2020 May;191(1):397-411. doi: 10.1007/s12010-020-03236-7. Epub 2020 Feb 4.
This study evaluated the performance of an upflow anaerobic filter (UAF) reactor in the thermophilic methane fermentation of hypersaline molasses wastewater. The high salinity (~ 45 mS/cm) of the undiluted wastewater completely inhibited the biogas production. An acclimation strategy involving gradient dilution of the molasses wastewater was implemented to gradually increase the salt stress. Consequently, the biogas production was recovered, inhibited only slightly by the high salinity of the undiluted wastewater. The reactor steadily achieved a high total organic carbon (TOC) loading rate of 5 g/L/day, with approximately 60% TOC removal efficiency. Acclimation to the gradually increased salt stress leads to a relative abundance of some halotolerant microbes, such as bacteria from Arcobacter, Tissierella, and Ruminococcaceae, which increased as their hydrolytic and acidogenic abilities adjusted to the incremental increase in salinity. Additionally, hydrogenotrophic methanogens, especially Methanoculleus, showed greater resistance to hypersalinity than aceticlastic methanogens. These results suggest that acclimation of the fermentation microbial community to hypersalinity is an effective strategy to improve methane production from hypersaline molasses wastewater in thermophilic UAF reactors.
本研究评估了上流式厌氧滤池（UAF）反应器在嗜热甲烷发酵高盐糖蜜废水中的性能。未稀释废水的高盐度（约 45 mS/cm）完全抑制了沼气的产生。采用逐渐稀释糖蜜废水的驯化策略来逐渐增加盐度胁迫。因此，沼气生产得到了恢复，仅受到未稀释废水高盐度的轻微抑制。该反应器稳定地实现了 5 g/L/天的高总有机碳（TOC）负荷率，TOC 去除效率约为 60%。对逐渐增加的盐度胁迫的适应导致一些耐盐微生物的相对丰度增加，例如来自 Arcobacter、Tissierella 和 Ruminococcaceae 的细菌，随着它们的水解和产酸能力适应盐度的增加而增加。此外，氢营养型产甲烷菌，特别是 Methanoculleus，对高盐度的抵抗力强于乙酸营养型产甲烷菌。这些结果表明，发酵微生物群落对高盐度的适应是提高嗜热 UAF 反应器中高盐糖蜜废水甲烷产量的有效策略。
