SINGLE-CELL ACTIVATED SLUDGE USING FILL-AND-DRAW FOR A
COMBINED INDUSTRIAL/DOMESTIC WASTE TREATMENT PLANT
John E. Rea, Jr., President
Multi-Mode Environmental Systems, Inc.
Oklahoma City, Oklahoma 73139
INTRODUCTION
INTRODUCTION
The Multi-Mode Waste Treatment Plant in Sapulpa, Oklahoma, placed in operation in
1971, provided the design parameters and basic observations that made possible the design of a one-basin fill-and-draw plant for the Oklahoma Gas and Electric Company at its
General Service Center on Southeast 74th Street in Oklahoma City in 1975.   The plant
was constructed and became operational in October 1975.
The Oklahoma Gas and Electric General Service Center has approximately 100 people
employed in the facility.   The functions of the center include a truck wash, a machine
shop, and a transformer overhaul shop, as well as a pole and equipment storage yard.
No sanitary sewage mains were available when the facility was constructed and domestic waste was treated in a large septic tank with a filter field providing for effluent disposal.   At a later time, the filter field was replaced with a small polishing lagoon that had
an effluent to the adjacent dry creek.   Industrial waste, consisting of the discharge from
the truck wash, the machine shop, and the transformer overhaul shop, was released untreated to the dry creek.
In 1974, Oklahoma Gas and Electric Company engaged our firm to design an industrial
waste plant to treat the oily discharge from the plant.   The Sapulpa plant successfully
treated the oil and grease from packinghouse waste, as well as several large oil spills.   Our
theory was that this could be accomplished successfully by combining domestic waste
with an oil or grease waste and treating the combination.   A bench-scale pilot plant was
placed in operation to confirm this theory.   The objective was to treat the industrial waste
to meet the 1977 EPA standards of biochemical oxygen demand of 20 mg/1,suspended
solids of 30 mg/1, and fecal coliform bacteria of 200/ml [ 1 ].
PLANT DESIGN
Results of the pilot plant operation were positive and a plant design was prepared.
Basis of the design was the Multi-Mode Waste Treatment Process as it was conceived in
observations from operation of the Sapulpa plant.
Minimum fluid detention time in the aeration basin is 48 hr.   This detention time is
for normal domestic waste and must be extended for industrial waste, where the volume
of volatile solids exceeds one ton per day per million gallons of aeration basin capacity,
or where the total oxygen demand exceeds 1800 lb to 2400 lb of oxygen per day.
Aerator horsepower per million gallons of aeration basin is 100 hp.   Assumed oxygen
transfer is 1 lb of oxygen per horsepower-hour to equal or exceed total oxygen demand
(not just five-day biochemical oxygen demand).   A mixing capacity to sustain mixed liquor
suspended solids of over 10,000 mg/1 is important.
No solids are wasted, except those lost in the effluent (normally 0-10 mg/1).   One hundred percent recycle of settled sludge to aeration basin is used.
The addition of a polymer, such as Calgon WT 3000, at an application rate of 1 mg/1
(in terms of aeration basin capacity) is needed to maintain low suspended solids loss in
effluent.
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