Investigating the Structure of Activated Sludge Flocs: Morphologic and Compositional Characterization of Surface and Bulk Components

Abstract The computerized image analysis system has been successfully used for determination and statistical processing of the following geometric characteristics of activated sludge flocs: longest dimension, breadth, equivalent diameter, cross-sectional area, perimeter, elongation, and circularity. These parameters could be effectively and precisely determined by the system applied. In addition, the studied method, as compared to direct microscope observation and photography floc-sizing methods, was found to be more accurate, less time-consuming, and less dependent on the investigators.

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Enrichment and characterization of an anaerobic methyl ethyl ketoxime degrading culture from an anoxic/anaerobic/aerobic activated sludge sequencing batch reactor

Water Science & Technology ◽

10.2166/wst.1998.0590 ◽

1998 ◽

Vol 37 (4-5) ◽

pp. 95-98 ◽

Cited By ~ 1

Author(s):

Nancy G. Love ◽

Mary E. Rust ◽

Kathy C. Terlesky

Keyword(s):

Energy Source ◽

Activated Sludge ◽

Electron Acceptor ◽

Sequencing Batch Reactor ◽

Enrichment Culture ◽

Batch Reactor ◽

Nitrification Inhibitor ◽

Time Frame ◽

Methyl Ethyl

An anaerobic enrichment culture was developed from an anoxic/anaerobic/aerobic activated sludge sequencing batch reactor using methyl ethyl ketoxime (MEKO), a potent nitrification inhibitor, as the sole carbon and energy source in the absence of molecular oxygen and nitrate. The enrichment culture was gradually fed decreasing amounts of biogenic organic compounds and increasing concentrations of MEKO over 23 days until the cultures metabolized the oxime as the sole carbon source; the cultures were maintained for an additional 41 days on MEKO alone. Turbidity stabilized at approximately 100 mg/l total suspended solids. Growth on selective media plates confirmed that the microorganisms were utilizing the MEKO as the sole carbon and energy source. The time frame required for growth indicated that the kinetics for MEKO degradation are slow. A batch test indicated that dissolved organic carbon decreased at a rate comparable to MEKO consumption, while sulfate was not consumed. The nature of the electron acceptor in anaerobic MEKO metabolism is unclear, but it is hypothesized that the MEKO is hydrolyzed intracellularly to form methyl ethyl ketone and hydroxylamine which serve as electron donor and electron acceptor, respectively.

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Deep learning-based morphology classification of activated sludge flocs in wastewater treatment plants

Environmental Science Water Research & Technology ◽

10.1039/d0ew00908c ◽

2021 ◽

Author(s):

Hisashi Satoh ◽

Yukari Kashimoto ◽

Naoki Takahashi ◽

Takashi Tsujimura

Keyword(s):

Wastewater Treatment ◽

Deep Learning ◽

Activated Sludge ◽

Morphological Change ◽

Wastewater Treatment Plants ◽

Filamentous Bacteria ◽

Sludge Flocs

A deep learning-based two-label classifier 1 recognized a 20% morphological change in the activated flocs. Classifier-2 quantitatively recognized an abundance of filamentous bacteria in activated flocs.

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