About Us | Help Videos | Contact Us | Subscriptions

Journal of Environmental Quality Abstract -

Physicochemical Changes Effected in Activated Sludge by the Earthworm Eisenia foetida1


This article in JEQ

  1. Vol. 10 No. 3, p. 377-381
    Received: Oct 9, 1979

Request Permissions

  1. Roy Hartenstein and
  2. Frances Hartenstein



Measurements were made of some physicochemical changes effected in activated sludge by the earthworm Eisenia foetida following conversion of the sludge into wormcasts. Mineralization was accelerated 1.3-fold and 2% of the minerals were assimilated. The rate at which heavy metals were concentrated during sludge catabolism was also accelerated. Castings stabilized within 2 weeks, as indexed by respirometry. Nucleic acids, which can be used as an index of microbial biomass, were present at a greater concentration in the wormcasts than in the sludge, while the phenolic content, which may potentially serve as an index of humification, was less concentrated. Other changes included a reduction in pH and an increase in oxidation-reduction potential and cation exchange capacity. The major general effect of E. foetida on the physicochemical properties of activated sludge is to convert a material which has a relatively small surface/volume ratio into numerous particles with an overall large S/V ratio, thus accelerating decomposition, mineralization, drying, and preclusion of malodor.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © .