Treatment of Cheese Processing Wastes by the
Bio-Disc Process
CARL W. BIRKS, Project Engineer
ROBERT J. HYNEK, Analytical Chemist
Bio-Systems Division
Autotrol Corporation
Milwaukee, Wisconsin
INTRODUCTION
In 1968, the Eiler Cheese Company decided to upgrade its wastewater
treatment plant in DePere, Wisconsin, to conform to State of Wisconsin Department
of Natural Resources water requirements. The existing treatment system consisted of
three 1,200 gallon septic tanks connected in series. The final effluent discharged into
a lagoon. This water basin, created by diversion of a natural stream, emptied into the
nearby East River.
Following receipt of the construction order from the Department of Natural
Resources, the plant owner retained the engineering firm of Foth & Van Dyke and
Associates in Green Bay, Wisconsin, to design a new waste treatment facility. This
firm sought a process capable of treating a high-strength waste under fluctuating
conditions. Equal consideration was given to process cost, dependability, maintenance, and power requirements.
Foth & Van Dyke determined that the BIO-DISC process with its unique
capabilities would best meet these requirements. Subsequently, a contract was
awarded to Autotrol Corporation to supply a BIO-DISC unit. The original contract
was awarded to Allis-Chalmers Mfg. Co. All assets, rights, and properties for the
BIO-DISC business were acquired by Autotrol Corporation in October, 1970. This
firm is also located in Milwaukee, Wisconsin. The Wisconsin Department of Natural
Resources gave experimental approval to the installation.
The BIO-DISC facility was activated in June of 1970. Performance of the
biological treatment plant since activation is the subject of this paper.
THE BIO-DISC PROCESS
As has been described in previous papers presented at Purdue Industrial Waste
Conferences, the BIO-DISC process is a secondary biological process (1). A large
biological surface area is provided by a series of closely spaced discs mounted on a
horizontal rotating shaft. The discs are slowly rotated through the waste liquid while
submerged to approximately 40 percent of their area.
An aerobic growth develops on the surface of the rotating discs. The thickness
of this biological growth is regulated by the penetration of oxygen to the deepest
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