The performance of the up-flow anaerobic sludge blanket (UASB) is significantly governed by the hydrodynamics of the reactor. Though the influence of hydrodynamics on mass transfer, granular size distribution, and biogas production was well studied, the interaction between biogas bubbles and anaerobic granular sludge (AGS) is poorly understood. This study used the impinging-jet technique and bubble probe atomic force microscope (AFM) to investigate the attachment and adhesion force between biogas bubbles (CH4 and CO2) and AGS. The fluxes of normalized CH4 or CO2 bubble-attachment on two kinds of AGS were directly affected by gas velocity and decreased with an increase in the Reynolds number ranged from 40 to 140. The bubble-attachment had a positive linear relationship with the contact angles, ratio of exopolymeric protein and polysaccharide, and hydrophilic functional groups of AGS. A bubble probe AFM was used to explore the adhesion force between a single bubble and AGS. The results indicated that the adhesion force between the bubbles and the two kinds of AGS also decreased with increasing approach velocity. Overall, these results contribute to a new insight into the understanding of interaction between biogas bubbles and AGS in UASB reactors.

中文翻译：

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上流厌氧污泥层中沼气与厌氧颗粒污泥之间的附着力和附着力。

上流式厌氧污泥层（UASB）的性能主要受反应器的流体动力学支配。尽管对流体动力学对传质，粒度分布和沼气生产的影响进行了深入研究，但对沼气气泡与厌氧颗粒污泥（AGS）之间的相互作用的了解却很少。这项研究使用撞击喷射技术和气泡探针原子力显微镜（AFM）来研究沼气气泡（CH4和CO2）与AGS之间的附着力和粘附力。两种AGS上归一化CH4或CO2气泡附着的通量直接受气体速度影响，并且随着雷诺数的增加（从40到140）而降低。气泡附着与接触角呈正线性关系，外聚合蛋白与多糖的比例，和AGS的亲水性官能团。使用气泡探针AFM探索单个气泡与AGS之间的粘附力。结果表明，气泡和两种AGS之间的附着力也随着接近速度的增加而减小。总体而言，这些结果为了解UASB反应器中沼气气泡与AGS之间的相互作用提供了新的见解。