K. Naddafi
Department of Environmental Health Engineering, Tehran University of Medical Sciences,
Tehran, P.O. Box 14155-6446, Iran
M. Zamanzadeh
Department of Environmental Health Engineering, Tehran University of Medical Sciences,
Tehran, P.O. Box 14155-6446, Iran
G. A. Omrani
Department of Environmental Health Engineering, Tehran University of Medical Sciences,
Tehran, P.O. Box 14155-6446, Iran
A. R. Mesdaghinia
Department of Environmental Engineering, University of Tehran,
Tehran, P.O. Box 14155-6135, Iran
A. A. Azimi
Department of Parasitology, Tehran University of Medical Sciences,
Tehran, P.O. Box 14155-6446, Iran
E. Mobedi
Department of Parasitology, Tehran University of Medical Sciences,
Tehran, P.O. Box 14155-6446, Iran
ABSTRACT
Sludge disposal has always represented a substantial portion of the costs associated with sewage treatment. In addition, the skilled personnel are not easily available to assure sound maintenance and operation of the conventional sludge treatment systems such as aerobic and anaerobic digestion; therefore, it is necessary to employ low cost and low technology practices in sludge management. Using earthworms in stabilization of sewage sludge, which has been approved by considerable work, can be a good alterative. This research was conducted to study the effect of stocking densities on sludge stabilization and sludge characteristics. In this regard, 40, 80 and 120 g earthworm wet weight were introduced into each of the plastic bins sizing 36 x 25 x 20 cm (length x width x height) to provide the desired stocking densities of 0.45, 0.90 and 1.35 kg worms m-2. Each bin received 2 kg waste activated sludge. The pilot-scale study showed that the highest VS (24.3%) reduction occurred in a stocking density of 1.35 kg Worm m-2 in which TKN and organic to mineral P ratio reduced 58.3 and 93.5 %, respectively.
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How to cite this article
K. Naddafi, M. Zamanzadeh, G. A. Omrani, A. R. Mesdaghinia, A. A. Azimi and E. Mobedi, 2006. Effect of Stocking Density on Vermistabilization of Waste Activated Sludge. Pakistan Journal of Biological Sciences, 9: 119-122.
DOI: 10.3923/pjbs.2006.119.122
URL: https://scialert.net/abstract/?doi=pjbs.2006.119.122
DOI: 10.3923/pjbs.2006.119.122
URL: https://scialert.net/abstract/?doi=pjbs.2006.119.122
REFERENCES
- Naddafi, K., M. Zamanzadeh, A.A. Azimi, G.A. Omrani, A.R. Mesdaghinia and E. Mobedi, 2004. Effect of temperature, dry solids and C/N ratio on vermicomposting of waste activated sludge. Pak. J. Biol. Sci., 7: 1217-1220.
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CrossRefDirect Link