Structure of Turbulence and Oxygen Transfer Mechanism
451
probability or the frequency of the collision.
SUMMARY
The results of this paper may be summarized as follows:
1. The structure of turbulence or the "micro-scale" of turbulence is never represented in
terms of the average input energy usually employed as the index of turbulence.
2. The scale of turbulence which has a direct influence on the coefficient "Kjja" or the
"oxygen uptake rate" is relatively small. The effect of the suspended solids becomes
apparent in this "scale" of turbulence.
3. Although the effects of suspended solids on the "Kj_/a" have been observed and
discussed by previous investigators, it can be said that similar effects of suspended solids
on the "oxygen uptake rate" occur. This shows the significance of the experimental data
reported by Sawyer and Nichols more than 30 years ago.
4. Due to the limitation of modern instruments complete quantitative analysis of
turbulence cannot yet be done. However, the shape, size or concentration of suspended
solids may be considered in obtaining a qualitative measure in order to characterize the
structure of turbulence.
5. To maintain biologically similar conditions the concentration of suspended solids as
well as the intensity of mixing or agitation must be taken into consideration.
ACKNOWLEDGEMENTS
The author wishes to express his appreciation to Dr. Akinori Sugiki, Professor of the
University of Tokyo, for his kind suggestions, and to Messrs. Hiroshi Ohta, Kazuo Noma
and Koichi Nakajo amd Mrs. Kazuko Noguchi for their cooperation and assistance in the
experiments and data analysis.
REFERENCES
1 KALINSKE, A.A., Turbulence diffusivity in activated sludge aeration basins. Presented at the 5ih
Intl. Conf. on Water Poll. Research, San Francisco, U.S.A., Paper No. II-7 (1970).
2 DAILY, J.W., BUGLIARELLO, G. and TROUTMANN, W.W., Measurement and analysis of
turbulent flow of wood pulp fiber suspension. Technical Report No. 35, Hydrodynamic
Laboratory, M.I.T., U.S.A. (1959).
3 DAILY, J.W. and ROBERTS, C.P.R., Rigid particle suspensions in turbulent shear flow: Size
effects with sperical particles. Technical Report No. 69. Hydrodynamic Laboratory, M.I.T., U.S.A.
(1964).
4 DICK, R.I. and EWING, B.B., The rheology of activated sludge. J.W.P.C.F. No. 4 Vol. 39, p.542
(1967).
5 CAMP, T.R., Flocculation and flocculations basins, Proc. A.S.C.E. No. 283, Vol. 179 (1953).
6 ECKENFELDER, W.W., Jr., Factors affecting the aeration efficiency of sewage and industrial
wastes. Sewage and Ind. Wastes. No. 1, Vol 31, p.61 (1959).
7 MANCY, K.H. and OKUN, D.A., Formal discussion to van der Kroon. Presented at the 4th Intl.
Conf. on Water Poll. Research. Paper 1-13, Prague, Czechoslovakia (1968).
8 VAN DER KROON, G.I.M., The influence of suspended solids on the rate of oxygen transfer in
aqueous solutions. Presented at the 4th Intl. Conf. on Water Poll. Research, Prague, Czechoslovakia
(1968).
9 PHILLIPS, D.H. and JOHNSON, M.J., Aeration in fermentations. J. Bioch. & Microbiol. Tech.
Eng. No. 3, Vol. Ill, p.277 (1961).
10 STEEL, R. and MAXON, W.D., Some effects of turbine size on novobiocin fermentations. Biotech.
451
probability or the frequency of the collision.
SUMMARY
The results of this paper may be summarized as follows:
1. The structure of turbulence or the "micro-scale" of turbulence is never represented in
terms of the average input energy usually employed as the index of turbulence.
2. The scale of turbulence which has a direct influence on the coefficient "Kjja" or the
"oxygen uptake rate" is relatively small. The effect of the suspended solids becomes
apparent in this "scale" of turbulence.
3. Although the effects of suspended solids on the "Kj_/a" have been observed and
discussed by previous investigators, it can be said that similar effects of suspended solids
on the "oxygen uptake rate" occur. This shows the significance of the experimental data
reported by Sawyer and Nichols more than 30 years ago.
4. Due to the limitation of modern instruments complete quantitative analysis of
turbulence cannot yet be done. However, the shape, size or concentration of suspended
solids may be considered in obtaining a qualitative measure in order to characterize the
structure of turbulence.
5. To maintain biologically similar conditions the concentration of suspended solids as
well as the intensity of mixing or agitation must be taken into consideration.
ACKNOWLEDGEMENTS
The author wishes to express his appreciation to Dr. Akinori Sugiki, Professor of the
University of Tokyo, for his kind suggestions, and to Messrs. Hiroshi Ohta, Kazuo Noma
and Koichi Nakajo amd Mrs. Kazuko Noguchi for their cooperation and assistance in the
experiments and data analysis.
REFERENCES
1 KALINSKE, A.A., Turbulence diffusivity in activated sludge aeration basins. Presented at the 5ih
Intl. Conf. on Water Poll. Research, San Francisco, U.S.A., Paper No. II-7 (1970).
2 DAILY, J.W., BUGLIARELLO, G. and TROUTMANN, W.W., Measurement and analysis of
turbulent flow of wood pulp fiber suspension. Technical Report No. 35, Hydrodynamic
Laboratory, M.I.T., U.S.A. (1959).
3 DAILY, J.W. and ROBERTS, C.P.R., Rigid particle suspensions in turbulent shear flow: Size
effects with sperical particles. Technical Report No. 69. Hydrodynamic Laboratory, M.I.T., U.S.A.
(1964).
4 DICK, R.I. and EWING, B.B., The rheology of activated sludge. J.W.P.C.F. No. 4 Vol. 39, p.542
(1967).
5 CAMP, T.R., Flocculation and flocculations basins, Proc. A.S.C.E. No. 283, Vol. 179 (1953).
6 ECKENFELDER, W.W., Jr., Factors affecting the aeration efficiency of sewage and industrial
wastes. Sewage and Ind. Wastes. No. 1, Vol 31, p.61 (1959).
7 MANCY, K.H. and OKUN, D.A., Formal discussion to van der Kroon. Presented at the 4th Intl.
Conf. on Water Poll. Research. Paper 1-13, Prague, Czechoslovakia (1968).
8 VAN DER KROON, G.I.M., The influence of suspended solids on the rate of oxygen transfer in
aqueous solutions. Presented at the 4th Intl. Conf. on Water Poll. Research, Prague, Czechoslovakia
(1968).
9 PHILLIPS, D.H. and JOHNSON, M.J., Aeration in fermentations. J. Bioch. & Microbiol. Tech.
Eng. No. 3, Vol. Ill, p.277 (1961).
10 STEEL, R. and MAXON, W.D., Some effects of turbine size on novobiocin fermentations. Biotech.