HANDLING OF ALUMINUM FORMING WASTEWATER
Jeffrey C. Carlton, Environmental Engineer
Garry R. Aronberg, Group Leader
Sverdrup & Parcel and Associates, Inc.
St. Louis, Missouri 63101
Donald R. Washington, Consultant
Pan American Health Organization
Kingston, Jamaica
Janet K. Goodwin, Project Officer
Ernst P. Hall, Chief
Metals and Machinery Branch
Effluent Guidelines Division
U.S. Environmental Protection Agency
Washington, DC 20460
From 1978 through 1981, Sverdrup & Parcel and Associates, Inc., was under contract
to the U.S. Environmental Protection Agency (EPA) to gather and analyze information
from the aluminum forming industry to serve as the basis for wastewater effluent limitations and standards. The data obtained and analyzed for this study indicated that significant amounts of oil and metals are present in aluminum forming wastewater streams. To
control the oil and metals, the industry utilizes a number of techniques which may also
be useful in controlling the wastewater from other industries. This chapter describes the
major wastewater treatment and recycling methods currently used by the aluminum forming
industry.
Aluminum forming includes 279 plants with manufacturing operations in which aluminum or aluminum alloys are made into semifinished products by hot or cold working.
These manufacturing operations include rolling, drawing, extruding and forging. Support
processes such as casting of aluminum for subsequent forming, heat treatment and cleaning
are also included. The EPA has grouped plants with these operations in the Aluminum
Forming Point Source Category.
Aluminum can manufacturing, which uses a forming process called drawing-and-ironing
to produce cans, is to be regulated under the coil coating industry regulations, since the
majority of wastewater produced by can manufacturing comes not from the drawing operation, but rather from the can cleaning and coating operations. However, this industrial
subcategory, which is made up of 38 plants, was originally studied as a part of the aluminum
forming industry and will be included in this chapter.
WASTEWATER CHARACTERISTICS
Wastewaters from the aluminum forming industry contain mainly oils and metals and
can be classified into four major groups: oil-in-water emulsions, spent free oils, process
cooling wastewaters and cleaning process wastewater. Sources, pollutant characteristics,
treatment methods and reuse methods for each of these wastewater classes are discussed
below.
Oil-in-Water Emulsions
Oil-in-water emulsions are used in the rolling and drawing operations in the aluminum
forming industry and the drawing-and-ironing operation in the can manufacturing industry.
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