Elsevier

Water Research

Volume 25, Issue 3, March 1991, Pages 313-317
Water Research

Foaming in activated sludge plants: A survey in Queensland, Australia and an evaluation of some control strategies

https://doi.org/10.1016/0043-1354(91)90011-EGet rights and content

Abstract

Activated sludge sewage treatment plants that were affected by biological foams attributed to the presence of actinomycetes were surveyed in Queensland, Australia.Nocardia amarae andNocardia pinensis were the predominant organisms found to accumulate selectively in the foam phase. Foaming was shown to be a significant problem in Queensland with 92% of surveyed plants being affected. A total of 60% of these plants suffered from bulking, however, no correlation between these two problems was noted. No operational, design, influent or weather feature was found to be consistent in all foaming plants. Apart from the fact that the plants were all variations of the activated sludge process, the only other aspect shared by them was that large numbers of filamentous bacteria were present in the foam. Field scale trials that evaluated control strategies against actinomycete foaming or scumming in activated sludge plants are described. The effects were assessed of: altering the rate of return activated sludge recycle, dosing of the aeration tank with anaerobic digester products, the addition of a commerical product specifically designed to control foaming, altering sludge age, varying levels of mixed liquor suspended solids (MLSS) and altering other operational features. These strategies did not efficaciously control scumming in activated sludge, however, some operational features were highlighted as exacerbating the problem.

Reference (31)

  • LudwigK.L.

    Foam control in aeration tanks Part III

    Wat./Engng Mgmt

    (1981)
    LudwigK.L.

    Foam control in aeration tanks Part III

    Wat./Engng Mgmt

    (1981)
  • Milwaukee mystery: unusual operating problem develops

    Wat. Swge Wks

    (1969)
  • BaumannM. et al.

    Microbial populations in activated sludge in relation to sewage treatment plant operation

  • BlackallL.L. et al.

    Nocardia pinensis sp. nov., an actinomycete found in activated sludge foams in Australia

    J. gen. Microbiol.

    (1989)
  • BlackbeardJ.R. et al.

    A survey of filamentous bulking and foaming in activated sludge plants in South Africa

    Wat. Pollut. Control

    (1986)
  • BlackbeardJ.R. et al.

    Identification of filamentous organisms in nutrient removal activated sludge plants in South Africa

    Wat. S. Afr.

    (1988)
  • BurdonK.L.

    Fatty material in bacteria and fungi revealed by staining dried, fixed slide preparations

    J. Bact.

    (1946)
  • CruickshankR. et al.

    Staining methods

  • DhaliwalB.S.

    Nocardia amarae and activated sludge foaming

    J. Wat. Pollut. Control Fed.

    (1979)
  • EikelboomD.H. et al.
  • GasserJ.A.

    Control ofNocardia scum in activated sludge by periodic anoxia

    J. Wat. Pollut. Control Fed.

    (1987)
  • GordonR.E.

    The taxonomy of bacteria

  • GordonR.E. et al.

    Resistance to rifampin and lysozyme of strains of some species ofMycobacterium andNocardia as a taxonomic tool

    Int. J. Sys. Bact.

    (1977)
  • HartM.A.

    Scum formation in a nutrient removing activated sludge plant

    Wat. S. Afr.

    (1985)
  • HartleyK.J.

    Nocardia in activated sludge plants

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