Department of Civil, Architectural and Environmental Engineering, Missouri University of Science and Technology, Rolla, MO, USA.
Department of Civil, Architectural and Environmental Engineering, Missouri University of Science and Technology, Rolla, MO, USA.
Chemosphere. 2019 May;223:694-703. doi: 10.1016/j.chemosphere.2019.02.088. Epub 2019 Feb 18.
The morphology of the microbial communities can have dramatic impacts on not only the treatment performance, but also the energy use performance of an activated sludge process. In this research, we developed and calibrated an image analysis technique to determine key morphological parameters such as the floc diameter and the specific filament length (SFL) and discovered that the SFL has significant impacts on sludge floc size, the specific extracellular polymeric substances production, the settleability, mixed liquor viscosity, and oxygen transfer efficiency. When the SFL increased from 2.5 × 10 μm g to 6.0 × 10 μm g, the apparent viscosity normalized by the mixed liquor suspended solids concentration increased by 67%, and the oxygen transfer efficiency decreased by 29%. A long solids retention time (SRT) of 40 day reduced SFL, improved sludge settling performance, and improved oxygen transfer efficiency as compared to shorter SRTs of 10 and 20 day. The findings underscore the need to assess microbial morphology when quantifying the treatment performance and energy performance of activated sludge processes.
微生物群落的形态对活性污泥工艺的处理性能和能源使用性能都有显著影响。在这项研究中，我们开发并校准了一种图像分析技术来确定关键的形态参数，如絮体直径和比丝状长度（SFL），并发现 SFL 对污泥絮体大小、特定胞外聚合物的产生、沉降性、混合液黏度和氧转移效率有显著影响。当 SFL 从 2.5×10μm g 增加到 6.0×10μm g 时，通过混合液悬浮固体浓度归一化的表观黏度增加了 67%，氧转移效率降低了 29%。与较短的 10 天和 20 天 SRT 相比，较长的 40 天固体停留时间（SRT）降低了 SFL，改善了污泥沉降性能，并提高了氧转移效率。这些发现强调了在量化活性污泥工艺的处理性能和能源性能时，需要评估微生物形态。
