School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
Guangdong Guangshen Environmental Protection Technology Co., Ltd., Guangzhou 510663, China.
J Environ Sci (China). 2025 Feb;148:579-590. doi: 10.1016/j.jes.2024.01.050. Epub 2024 Feb 12.
This work established a quantitative method to access the shear stability of aerobic granular sludge (AGS) and validated its feasibility by using the mature AGS from a pilot-scale (50 tons/day) membrane bioreactor (MBR) for treating real municipal wastewater. The results showed that the changing rate (ΔS) of the peak area (S) of granule size distribution (GSD) exhibited an exponential relationship (R≥0.76) with the shear time (y=a-b·c), which was a suitable indicative index to reflect the shear stability of different AGS samples. The limiting granule size (LGS) was defined and proposed to characterize the equilibrium size for AGS after being sheared for a period of time, whose value in terms of Dv50 showed high correlation (R=0.92) with the parameter a. The free Ca (28.44-34.21 mg/L) in the influent specifically interacted with polysaccharides (PS) in the granule's extracellular polymeric substance (EPS) as a nucleation site, thereby inducing the formation of Ca precipitation to enhance its Young's modulus, while Ca primarily interacted with PS in soluble metabolic product (SMP) during the initial granulation process. Furthermore, the Young's modulus significantly affected the parameter a related to shear stability (R=0.99). Since the parameter a was more closely related (R=1.00) to ΔS than that of the parameter b or c, the excellent correlation (R=0.99) between the parameter a and the wet density further verified the feasibility of this method.
本研究建立了一种定量方法来评估好氧颗粒污泥（AGS）的抗剪切稳定性，并通过使用来自处理实际城市污水的中试规模（50 吨/天）膜生物反应器（MBR）的成熟 AGS 验证了其可行性。结果表明，颗粒大小分布（GSD）的峰面积（S）的变化率（ΔS）与剪切时间（y=a-b·c）呈指数关系（R≥0.76），这是反映不同 AGS 样品抗剪切稳定性的合适指标。定义并提出了极限颗粒大小（LGS），以表征 AGS 在一段时间的剪切后达到的平衡尺寸，其值在 Dv50 方面与参数 a 高度相关（R=0.92）。进水（28.44-34.21mg/L）中的游离 Ca 与颗粒细胞外聚合物（EPS）中的多糖（PS）特异性相互作用作为成核点，从而诱导 Ca 沉淀的形成以增强其杨氏模量，而 Ca 主要在初始颗粒化过程中与可溶性代谢产物（SMP）中的 PS 相互作用。此外，杨氏模量显著影响与抗剪切稳定性相关的参数 a（R=0.99）。由于参数 a 与剪切稳定性的相关性（R=1.00）比参数 b 或 c 更为密切，参数 a 与湿密度之间的优异相关性（R=0.99）进一步验证了该方法的可行性。
