State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
Water Res. 2024 Oct 1;263:122093. doi: 10.1016/j.watres.2024.122093. Epub 2024 Jul 14.
Anammox granular sludge (AnGS) has received considerable attention due to its low carbon footprint (less aeration energy and carbon source consumption) and high biomass density, but growth rate and stability are still the bottlenecks of AnGS process. Calcium ion (Ca) is essential for the growth of anaerobic ammonium oxidation bacteria (AnAOB) and plays an important role in the formation and stability of AnGS. Response of AnGS to Ca under different concentrations was comprehensively investigated by multi-spectral and metagenomics analysis in four aspects: nitrogen removal performance, surface morphology, extracellular polymeric substance (EPS) composition and characterization, and microbial community. The nitrogen removal efficiency was significantly enhanced at appropriate Ca concentration (2 mmol/L), owning to the more favorable morphology and functional microbial composition of AnGS. However, the nitrogen removal performance of AnGS declined with the Caconcentration increased from 2 to 8 mmol/L, due to the negative effects of excess Caon EPS, mass transfer efficiency, and functional microorganisms. Meanwhile, an unexpected slight "rebound" of nitrogen removal efficiency was observed at Ca = 6 mmol/L and attributed to the defense mode transformation of AnGS (from "ion stabilization" to "precipitate shield" modes) against excess Ca stress. Based on the findings, the response mechanism of AnGS to Ca with different concentrations was established. Our results enhanced the understanding of the interaction between AnGS and Ca, which may be valuable for filling the theoretical gap in enhancing the granulation and stability of AnGS and providing a reference for the practical operation of the AnGS process.
厌氧氨氧化颗粒污泥（AnGS）因其碳足迹低（耗氧量和碳源消耗少）和生物量密度高而受到广泛关注，但生长速率和稳定性仍然是 AnGS 工艺的瓶颈。钙离子（Ca）是厌氧氨氧化菌（AnAOB）生长所必需的，在 AnGS 的形成和稳定中起着重要作用。本研究通过多光谱和宏基因组学分析，从脱氮性能、表面形态、胞外聚合物（EPS）组成和特性以及微生物群落四个方面综合研究了不同浓度 Ca 对 AnGS 的响应。在适当的 Ca 浓度（2 mmol/L）下，氮去除效率显著提高，这归因于 AnGS 更有利的形态和功能微生物组成。然而，随着 Ca 浓度从 2 mmol/L 增加到 8 mmol/L，AnGS 的氮去除性能下降，这是由于过量 Ca 对 EPS、传质效率和功能微生物的负面影响。同时，在 Ca = 6 mmol/L 时观察到氮去除效率的意外轻微“反弹”，这归因于 AnGS 对过量 Ca 胁迫的防御模式转变（从“离子稳定”模式转变为“沉淀屏蔽”模式）。基于这些发现，建立了 AnGS 对不同浓度 Ca 的响应机制。本研究结果增强了对 AnGS 与 Ca 之间相互作用的理解，这可能有助于填补增强 AnGS 颗粒化和稳定性的理论空白，并为 AnGS 工艺的实际运行提供参考。
Zotero 插件