State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China; CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China.
Sci Total Environ. 2024 Nov 10;950:175286. doi: 10.1016/j.scitotenv.2024.175286. Epub 2024 Aug 5.
The production of short-chain fatty acids (SCFAs) from sludge is promising, but the efficiency and product quality often vary because of extracellular polymeric substances (EPS) characteristics and pretreatment principles. This study adopted specific EPS disintegration pretreatment to treat different types of sludge. By correlation coefficient matrix analysis and correlation dynamics change resolution, the intrinsic relationships between the nature of EPS and the production of SCFAs from sludge was unveiled. We demonstrate that tight-bound EPS (TB-EPS) is a principal carbon reservoir, positively impacting SCFAs yields, in the fermentation system with EPS as the main fermentation substrate, it can contribute about 29.2 % for SCFAs growth during fermentation. Conversely, TB-EPS exhibits a negative correlation during fermentation due to EPS-SCFAs interconversion, while loosely bound EPS (LB-EPS) correlates positively. Proteins and polysaccharides in TB-EPS, especially proteins, significantly enhance individual SCFAs yields, predominantly acetic, propionic, and isovaleric acids. The findings would provide a theoretical basis for developing pretreatments and process-control technologies aimed at improving SCFAs production efficiency and quality.
从污泥中生产短链脂肪酸（SCFAs）具有广阔的前景，但由于胞外聚合物（EPS）的特性和预处理原则，效率和产品质量往往存在差异。本研究采用特定的 EPS 解体预处理方法来处理不同类型的污泥。通过相关系数矩阵分析和相关动力学变化分辨率，揭示了 EPS 性质与污泥中 SCFAs 产生之间的内在关系。我们证明，紧密结合的 EPS（TB-EPS）是主要的碳库，在以 EPS 为主要发酵基质的发酵系统中，它可以为发酵过程中 SCFAs 的生长贡献约 29.2%。相反，由于 EPS-SCFAs 的相互转化，TB-EPS 在发酵过程中呈负相关，而松散结合的 EPS（LB-EPS）呈正相关。TB-EPS 中的蛋白质和多糖，尤其是蛋白质，显著提高了个别 SCFAs 的产量，主要是乙酸、丙酸和异戊酸。这些发现将为开发旨在提高 SCFAs 生产效率和质量的预处理和过程控制技术提供理论依据。
