Naddafi K

Are you Naddafi K?

Claim your profile

Publications (2)0 Total impact

  • Article: Effect of Stocking Density on Vermistabilization of Waste Activated Sludge
    Naddafi K, Zamanzadeh M, G. A. Omrani, A. R. Mesdaghinia, A. A. Azimi, Mobedi E
    [show abstract] [hide abstract]
    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<sup>-2</SUP>. 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<SUP>-2</SUP> in which TKN and organic to mineral P ratio reduced 58.3 and 93.5 %, respectively.
    Pakistan Journal of Biological Sciences. 01/2006;
  • Article: Effect of Temperature, Dry Solids and C/N Ratio on Vermicomposting of Waste Activated Sludge
    Naddafi K, Zamanzadeh M, A. A. Azimi, G. A. Omrani, A. R. Mesdaghinia, Mobedi E
    [show abstract] [hide abstract]
    ABSTRACT: The effect of temperature, dry solids and C/N ratio on the growth of E. fetida and on vermicomposting of waste activated sludge was studied in a small-scale laboratory experiments. The maximum growth rate in 25�C, 15-20% dry solids and a C/N ratio of 15 were 19�1, 21�2 and 20�2 mg/worm/day, respectively. Moreover, changes in the physicochemical properties of the produced vermicasts were assessed. The highest VS reduction (18%) occurred in dry solids of 15% and in a C/N ratio of 25 the maximum VS reduction was 17%. TKN decreased with increase in dry solids by the end of vermicomposting process, while the highest organic to mineral P reduction occurred in the dry solids of 15%. The results for different levels of C/N ratio showed that TKN and organic to mineral P of the worm-worked waste activated sludge decreased with increase in C/N ratio. The pH of the produced vermicompost in different levels of dry solids and C/N ratio increased in all the experiments.
    Pakistan Journal of Biological Sciences. 01/2004;
Browse more researchers