PS-Fe预处理提升污泥厌氧发酵提取 SCFAs效能的研究

Research on the Enhancement of SCFAs Extraction Efficiency in Sludge Anaerobic Fermentation by PS-Fe Pretreatment

摘要

剩余污泥（WAS）厌氧发酵生产短链脂肪酸（SCFAs）具有广泛的应用前景，但效率偏低。本研究采用过硫酸盐-铁（PS-Fe）预处理技术，系统探究了运行条件对提升SCFAs产量及组分的影响。结果显示，在PS与Fe的摩尔比为1.5∶1、PS投加量为1.0 mmol/g TSS、发酵温度35 ℃、污泥浓度40 g TSS/L、pH值为7.0~7.5的优化条件下，SCFAs产量达138.70 mg COD/g VSS，较对照组提升10.58倍，其中乙酸占比74.35%。研究进一步发现，PS-Fe预处理破坏了胞外聚合物与细胞的结构，使得蛋白质、多糖和DNA的浓度分别提高了0.8、1.3和13.7倍，激活了蛋白酶、 α-葡萄糖苷酶及乙酸激酶的活性，促使优势发酵类型从丙酸发酵（占比55.84%）转变为乙酸发酵（占比74.35%）。本研究揭示了PS-Fe预处理促进SCFAs生成的可行性及其机制，为从WAS中高效回收生物质提供了有价值的参考。

Abstract

The anaerobic fermentation of waste activated sludge (WAS) for the production of short-chain fatty acids (SCFAs) holds broad application prospects, but its efficiency remains relatively low. This study employs the PS-Fe pretreatment technology to systematically investigate the effects of operating conditions on enhancing SCFAs production and composition. The results show that under the optimized conditions-PS to Fe molar ratio of 1.5∶1, PS dosage of 1.0 mmol/g TSS, fermentation temperature of 35 ℃, sludge concentration of 40 g TSS/L, and pH of 7.0-7.5-the SCFAs yield reaches 138.70 mg COD/g VSS, representing a 10.58-fold increase compared to the control group, with acetic acid accounting for 74.35%. Further research reveals that PS-Fe pretreatment disrupts the structure of extracellular polymeric substances (EPS) and cells, leading to increased concentrations of protein, polysaccharide, and DNA by 0.8, 1.3, and 13.7 times, respectively. Additionally, it activates the activities of protease, α-glucosidase, and acetate kinase, shifting the dominant fermentation type from propionic acid fermentation (accounting for 55.84%) to acetic acid fermentation (accounting for 74.35%). This study demonstrates the feasibility and underlying mechanism of PS-Fe pretreatment in promoting SCFAs generation, thereby offering valuable insights for the efficient recovery of biomass from WAS.

关键词

PS-Fe预处理 / 短链脂肪酸 / 剩余污泥 / 乙酸发酵 / 胞外聚合物

Key words

PS-Fe pretreatment / short chain fatty acids / waste activated sludge / acetic acid fermentation / extracellular polymeric substances

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基金资助

中铁（泰安）环境治理有限公司研究项目(JSS242402)

山东省重点研发计划(2023TZXD019)