A Low Cost Open Tank Pure Oxygen System
399
ANNUAL COST
I. 50 tons/day undigested WAS x $60/ton x 365
$ 1,095,000
II. a)
34 tons/day undigested WAS x $60/ton x 365
744,600
b)
16 tons/day digested WAS x $20/ton x 365
116,800
Total waste activated sludge disposal cost with
conventional aerobic digestion
861,400
Net annual savings due to aerobic digestion
233,600
Potential savings in sludge disposal costs based on 70% mass reduction using pure
oxygen ($10/ton) compared with handling undigested waste activated sludge are as follows:
III. a)
35 tons/day digested x $20/ton x 365
$ 255,500
b)
15 tons/day undigested x $60/ton x 365
328,500
Total waste activated sludge disposal cost with pure oxygen
584,000
Estimated annual savings due to pure oxygen
511,000
A benefit/cost ratio of 2.0 can thus be realized in this unit operation provided that
oxygen can be obtained for $10/ton. The cost figure for oxygen is based on data supplied
by Union Carbide Company in their Batavia report for large plants using more than 100
tons per day.
In summary, these areas of "open tank" pure oxygen treatment, while intended
initially for solving a local problem at the Metro Denver Sewage Disposal Plant may
become directly pertinent internationally for many other overloaded waste treatment
plants. This new technological breakthrough in oxygen transfer efficiency has the
capability of more closely approximating an "ideal" activated sludge system than any
other known modification by "doing more with less".
REFERENCES
OKUN, D.A., "System of Bio-Precipitation of Organic Matter from Sewage", Sewage Works
Journal, 21, 1949.
BUDD, W.E. and LAMBETH, G.F., "High Purity Oxygen in Biological Sewage Treatment", Sewage
and Industrial Wastes, 29, 253, 1957.
OKUN, DA. and LYNN, W.R., "Preliminary Investigation into the Effect of Oxygen Tension on
Biological Sewage Treatment", in Biological Treatment of Sewage and Industrial Wastes: Vol. I,
Aerobic Oxidation, Reinhold Publishing Corp., New York 1956.
OKUN, D.A., "Discussion of High Purity Oxygen in Biological Sewage Treatment", Sewage and
Industrial Wastes, 29, 253, 1957.
McKINNEY, R.E. and PFEIFFER, J.T., "Oxygen-Enriched Air for Biological Waste Treatment",
Water and Sewage Works, October, 1965^
ALBERTSSON, J.G., McWHIRTER, J.R., ROBINSON, E.K. and VAHLDIECK, N.P.,
"Investigation of the Use of High Purity Oxygen Aeration in the Conventional Activated Sludge
Process", FWQA Department of the Interior Program No. 17050 DNW, Contract No. 14-12-465,
May 1970.
399
ANNUAL COST
I. 50 tons/day undigested WAS x $60/ton x 365
$ 1,095,000
II. a)
34 tons/day undigested WAS x $60/ton x 365
744,600
b)
16 tons/day digested WAS x $20/ton x 365
116,800
Total waste activated sludge disposal cost with
conventional aerobic digestion
861,400
Net annual savings due to aerobic digestion
233,600
Potential savings in sludge disposal costs based on 70% mass reduction using pure
oxygen ($10/ton) compared with handling undigested waste activated sludge are as follows:
III. a)
35 tons/day digested x $20/ton x 365
$ 255,500
b)
15 tons/day undigested x $60/ton x 365
328,500
Total waste activated sludge disposal cost with pure oxygen
584,000
Estimated annual savings due to pure oxygen
511,000
A benefit/cost ratio of 2.0 can thus be realized in this unit operation provided that
oxygen can be obtained for $10/ton. The cost figure for oxygen is based on data supplied
by Union Carbide Company in their Batavia report for large plants using more than 100
tons per day.
In summary, these areas of "open tank" pure oxygen treatment, while intended
initially for solving a local problem at the Metro Denver Sewage Disposal Plant may
become directly pertinent internationally for many other overloaded waste treatment
plants. This new technological breakthrough in oxygen transfer efficiency has the
capability of more closely approximating an "ideal" activated sludge system than any
other known modification by "doing more with less".
REFERENCES
OKUN, D.A., "System of Bio-Precipitation of Organic Matter from Sewage", Sewage Works
Journal, 21, 1949.
BUDD, W.E. and LAMBETH, G.F., "High Purity Oxygen in Biological Sewage Treatment", Sewage
and Industrial Wastes, 29, 253, 1957.
OKUN, DA. and LYNN, W.R., "Preliminary Investigation into the Effect of Oxygen Tension on
Biological Sewage Treatment", in Biological Treatment of Sewage and Industrial Wastes: Vol. I,
Aerobic Oxidation, Reinhold Publishing Corp., New York 1956.
OKUN, D.A., "Discussion of High Purity Oxygen in Biological Sewage Treatment", Sewage and
Industrial Wastes, 29, 253, 1957.
McKINNEY, R.E. and PFEIFFER, J.T., "Oxygen-Enriched Air for Biological Waste Treatment",
Water and Sewage Works, October, 1965^
ALBERTSSON, J.G., McWHIRTER, J.R., ROBINSON, E.K. and VAHLDIECK, N.P.,
"Investigation of the Use of High Purity Oxygen Aeration in the Conventional Activated Sludge
Process", FWQA Department of the Interior Program No. 17050 DNW, Contract No. 14-12-465,
May 1970.