Letter | Published:

Vorticella as an Indicator Organism for Activated Sludge

Nature volume 149, pages 608609 (30 May 1942) | Download Citation



IT has been recognized for a number of years that the type of protozoan fauna inhabiting activated sludge in a sewage purification plant of this type affords a useful indication of the condition of the sludge. In 1936, Ardern and Lockett1 stated that they considered this test as the most useful in determining the activity of sludge and listed the common types associated with varying conditions. More recently, Barritt2 has further enlarged their general findings. It has been concluded that the presence of ciliates and particularly the peritriches to the exclusion of other classes of Protozoa generally indicates a ripe active sludge. But the scope of the utility of this test has been limited by the fact that they were usually qualitative and therefore complementary only to the quantitative chemical analyses.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    , and , Proc. Inst. Sew. Purif., 1 (1936).

  2. 2.

    , Ann. Appl. Biol, 27, 151 (1940).

  3. 3.

    , Proc. Inst. Sew. Purif., 1941 (in the press).

  4. 4.

    "Methods of Chemical Analysis as applied to Sewage and Sewage Effluents" (H.M. Stationery Office, 1929).

  5. 5.

    , "Statistical Calculation for Beginners" (Cambridge Univ. Press, 1940).

Download references

Author information


  1. Biochemical Laboratory, Huddersfield Corporation Sewage Works Department, Deighton, Huddersfield. May 4.



  1. Search for T. B. REYNOLDSON in:

About this article

Publication history





By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.