1887

Abstract

SUMMARY: To enumerate the bacteria present in activated sludge it is necessary to release them undamaged from the flocs. Samples of diluted activated sludge were sonicated for periods ranging from 20 to 240 s at five different intensities. During sonication, floc disruption was followed by measuring the absorbance of treated samples at 400 and 610 nm, energy input by recording changes in temperature and the release of viable organisms by plating techniques.

The release of bacteria depended on the intensity and duration of sonication. Most viable bacteria were recovered after 80 to 100 s at a power output of 26 J s. Patterns of recovery of viable bacteria from 10 different activated sludges were of two types. Comparable recovery of bacteria from identical samples showed that two instruments could be successfully compared using physical criteria only.

After sonication the number of bacteria recovered depended on the isolation medium. More bacteria were recovered from Casitone glycerol yeast extract agar than from Tryptone glucose beef and yeast extract vitamins agar (TGEVA) for five out of six sludges, and more were recovered from minimal pyruvate than from TGEVA for three out of six sludges.

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/content/journal/micro/10.1099/00221287-98-2-363
1977-02-01
2021-08-04
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References

  1. Allen L.A. 1944; The bacteriology of activated sludge. Journal of Hygiene, Cambridge 43:424–431
    [Google Scholar]
  2. Banks C.J., Davies M., Walker I., Ward R.D. 1976; Biological and physical characterisation of activated sludge: a comparative experimental study at ten treatment plants. Water Pollution Control 75:492–508
    [Google Scholar]
  3. Kiff R.J. 1975 A study of the ecological factors influencing the efficiency of the activated sludge system for treating organic wastes. Ph.D. thesis, University of Aston
    [Google Scholar]
  4. Lighthart B., Oglesby R.T. 1969; Bacteriology of an activated sludge wastewater treatment plant - a guide to methodology. Journal of the Water Pollution Control Federation 41:267–281
    [Google Scholar]
  5. Meynell G.G., Meynell E. 1965 Theory and Practice in Experimental Bacteriology, 1st edn.. London: Cambridge University Press;
    [Google Scholar]
  6. Pike E.B., Carrington E.G., Ashburner P.A. 1972; An evaluation of procedures for enumerating bacteria in activated sludge. Journal of Applied Bacteriology 35:309–321
    [Google Scholar]
  7. Prakasam T.B.S., Dondero N.C. 1967a; Aerobic heterotrophic bacterial populations of sewage and activated sludge.I.Enumeration. Applied Microbiology 15:461–467
    [Google Scholar]
  8. Prakasam T.B.S., Dondero N.C. 1967b; Aerobic heterotrophic bacterial populations of sewage and activated sludge.III.Adaptation in a synthetic waste. Applied Microbiology 15:1128–1137
    [Google Scholar]
  9. Unz R.F., Davis J.A. 1975; Microbiology of combined chemical-biological treatment. Journal of the Water Pollution Control Federation 47:185–194
    [Google Scholar]
  10. Weddle C.L., Jenkins D. 1971; The viability and activity of activated sludge. Water Research 5:621–640
    [Google Scholar]
  11. Williams A.R., Stafford D.A., Calley A.G., Hughes D.E. 1970; Ultrasonic dispersal of activated sludge floes. Journal of Applied Bacteriology 33:656–663
    [Google Scholar]
  12. Williams A.R., Forster C.F., Hughes D.E. 1971; Using an ultrasonic technique in enumeration of activated sludge bacteria. Effluent Water Treatment Journal 11:83–86
    [Google Scholar]
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