Characterization of activated sludge abnormalities by image analysis and chemometric techniques

This work focuses on the use of chemometric techniques for identifying activated sludge process abnormalities. Chemometric methods combined with image analysis can improve activated sludge systems monitoring and minimize the need of analytical measurements. For that purpose data was collected from aggregated and filamentous biomass, biomass composition on Gram-positive/Gram-negative bacteria and viable/damaged bacteria, and operational parameters. Principal component analysis (PCA) was subsequently applied to identify activated sludge abnormalities, allowing the identification of several disturbances, namely filamentous bulking, pinpoint flocs formation, and zoogleal bulking as well as normal conditions by grouping the collected samples in corresponding clusters.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Image analysis and PCA techniques were applied to an activated sludge system. ► Aggregated and filamentous biomass, Gram status and viability were characterized. ► Several abnormalities were identified combining image analysis and PCA. ► Monitoring activated sludge improved using chemometric methods and image analysis.