BIOLOGICAL TREATMENT OF COKE PLANT WASTE
UTILIZING AN INTEGRAL CLARIFICATION CONCEPT
Myrl R. Wear, Senior Environmental Engineer
James A. Grantz, Environmental Engineer
Ronald J. Thompson, Supervising Project Engineer
Armco Environmental Engineering
Armco, Inc.
Middletown, Ohio 45043
INTRODUCTION
Armco's Hamdton plant is located in New Miami, Ohio, on the Great Miami River. The
plant  produces  molten pig iron, metallurgical coke, coke gas, and coking by-products.
The HamUton Coke Plant consists of four Koppers-Becker underjet design batteries
with a total of 110 ovens. The oldest battery was constructed in 1928 and the newest
started up in 1947. During this period the batteries have been rebudt several times.
In 1976, Armco initiated an extensive modification and rehabditation program for aU
four coke batteries. A major part of this program was the installation of state-of-the-art
air and water pollution control facdities. The water pollution control program included the
collection and treatment of sanitary sewage, ammonia stdl waste, benzol plant waste, quench
tower waste, and high temperature noncontact cooling water. This paper specifically deals
with the treatment of the sanitary sewage, ammonia stdl waste, and the benzol plant waste.
BACKGROUND
The wastewaters generated at Armco's HamUton Coke Plant are primarily from the
flushing liquor system and the benzol plant. The flushing liquor is hot water which is
sprayed directly into the collecting mains to quench coke oven gas as it leaves the ovens.
A circulating liquor system is used to cool the gas in direct spray primary coolers. Water
evaporated from the coal is condensed in the main and primary coolers creating excess
flushing liquor. This highly contaminated excess liquor from the two systems is collected
in storage tanks'prior to treatment.
Several sources of wastewater from the benzol plant are collected in a common od
separation sump. The largest source is condensate from wash oU/crude light od distillation operations. The wash od is purified by steam stripping to remove crude light od
that was absorbed in the light oU gas scrubbers. The steam condensate is discharged to the
benzol sump as a contaminated waste stream. See Table 1 for the design volumes and
chemical composition of the raw excess ammonia liquor and benzol plant wastewater.
At the outset of the program, a study was conducted to determine the best approach
for treating coke plant wastewater. Alternatives studied and rejected included physical-
chemical treatment with activated carbon and joint treatment in a publicly owned treatment
works (POTW). The physical-chemical scheme offered a lower capital investment but a much
higher operating cost and was thus rejected. The joint treatment scheme was rejected because of the remote location of the coke plant and the unique configuration of the POTW.
Thus, a combination of physical-chemical treatment followed by biological treatment was
chosen. The major treatment objective was compliance with NPDES permit requirements.
In order to meet this objective, each major waste stream had to be pretreated by physical-
chemical methods to remove incompatible pollutants prior to biological treatment.
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