Shaanxi Key Laboratory of Environmental Engineering, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Shaanxi Key Laboratory of Environmental Engineering, School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Bioresour Technol. 2022 Mar;347:126337. doi: 10.1016/j.biortech.2021.126337. Epub 2021 Nov 13.
This study proposed a novel and high-efficiency strategy, i.e., freezing followed by low-temperature thermal treatment, to significantly promote short-chain fatty acids (SCFAs) production from waste activated sludge compared to traditional freezing/thawing treatment. The maximal production of SCFAs was 212 mg COD/g VSS with a shortened retention time of five days, and the potentially recovered carbon source, including SCFAs, soluble polysaccharides and proteins, reached 321 mg COD/g VSS, increased by 92.1 and 28.3% compared to sole freezing and thermal treatment. Both the solubilization and hydrolysis steps of WAS were accelerated, and the acid-producing microorganisms, such as Macellibacteroides, Romboutsia and Paraclostridium, were greatly enriched, with a total abundance of 13.9%, which was only 0.54% in control. Interestingly, the methane production was inhibited at a shortened retention time, resulting in SCFAs accumulation, whereas it was increased by 32.0% at a longer sludge retention time, providing a potential solution for energy recovery from WAS.
本研究提出了一种新颖且高效的策略，即冷冻后进行低温热处理，与传统的冷冻/解冻处理相比，可显著促进废活性污泥中短链脂肪酸（SCFAs）的生成。该策略下 SCFAs 的最大产量为 212mg COD/g VSS，停留时间缩短至 5 天，潜在可回收的碳源（包括 SCFAs、可溶性多糖和蛋白质）达到 321mg COD/g VSS，分别比单独冷冻和热处理提高了 92.1%和 28.3%。WAS 的溶解和水解步骤均得到加速，产酸微生物（如 Macellibacteroides、Romboutsia 和 Paraclostridium）得到极大富集，丰度达到 13.9%，而在对照中仅为 0.54%。有趣的是，在缩短停留时间时，甲烷生成受到抑制，导致 SCFAs 积累，而在较长的污泥停留时间时，甲烷生成增加了 32.0%，为从 WAS 中回收能源提供了一种潜在的解决方案。
