Assessing Activated Sludge Morphology and Oxygen Transfer Performance using Image Analysis
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 x 10 9 µm g −1 to 6.0 x 10 10 µm g −1 , 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.
K. Campbell et al., "Assessing Activated Sludge Morphology and Oxygen Transfer Performance using Image Analysis," Chemosphere, pp. 694-703, Elsevier Ltd, May 2019.
The definitive version is available at https://doi.org/10.1016/j.chemosphere.2019.02.088
Civil, Architectural and Environmental Engineering
Keywords and Phrases
Activated sludge; Apparent viscosity; Floc diameter; Morphology; Oxygen transfer efficiency; Specific filament length
International Standard Serial Number (ISSN)
Article - Journal
© 2019 Elsevier Ltd, All rights reserved.
01 May 2019