State Key Lab of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
State Key Lab of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
Sci Total Environ. 2023 Apr 20;870:161924. doi: 10.1016/j.scitotenv.2023.161924. Epub 2023 Jan 31.
Wasted activated sludge (WAS) is a promising feedstock for carbon management because of its abundance and carbon-neutral features. Currently, the goal is to maximize the energy in WAS and avoid secondary toxic effects or accumulation of harmful substances in the environment. Chemical pretreatment is an effective strategy for enhancing WAS disintegration and production of short chain fatty acids (SCFAs). However, the role of pretreatment in shaping the core microbiome and functional metabolism of anaerobic microorganisms remains obscure. Here, the mechanisms of SCFA synthesis and microbiome response to free nitrous acid (FNA) and calcium peroxide (CaO) co-treatment during sludge anaerobic digestion (AD) were investigated. The combination of FNA and CaO enriched acidogenic Macellibacteroides, Petrimonas, and Sedimentibacter to a relative abundance of 15.0%, 10.3%, and 7.3%, respectively, resulting in an apparent increase in SCFA production. Metagenome analysis indicated that FNA + CaO co-treatment facilitated glycolysis, phosphate acetyltransferase-acetate kinase pathway, amino acid metabolism, and acetate transport, but inhibited CO reduction and common pathway of methanogenesis compared with the untreated control. This work provides theoretical insights into the functional activity and interaction of microorganisms with ecological factors.
剩余活性污泥（WAS）是一种很有前途的碳管理原料，因为它丰富且具有碳中性的特点。目前，目标是最大限度地提高 WAS 中的能量，并避免在环境中产生二次毒性或有害物质的积累。化学预处理是增强 WAS 分解和生产短链脂肪酸（SCFAs）的有效策略。然而，预处理在塑造厌氧微生物的核心微生物组和功能代谢方面的作用仍不清楚。在这里，研究了在污泥厌氧消化（AD）过程中，游离亚硝酸（FNA）和过氧化钙（CaO）共处理对 SCFA 合成和微生物组的影响机制。FNA 和 CaO 的组合使产酸菌 Macellibacteroides、Petrimonas 和 Sedimentibacter 富集到相对丰度的 15.0%、10.3%和 7.3%，从而明显增加了 SCFA 的产量。宏基因组分析表明，与未经处理的对照组相比，FNA + CaO 共处理促进了糖酵解、磷酸乙酰转移酶-乙酰激酶途径、氨基酸代谢和乙酸转运，但抑制了 CO 还原和常见的甲烷生成途径。这项工作为功能活性和微生物与生态因素的相互作用提供了理论见解。
