Industrial Wastes from Scouring Rug
Wools and the Removal of Dieldrin
ROBERT D. WILROY, Project Engineer
Wiedeman and Singleton, Engineers
Atlanta, Georgia
At the present time in the United States there is a tremendous movement of
industry from one area of the country to another. There are many factors which
control these movements such as favorable labor supply, transportation, markets,
availability of raw materials, and an adequate water supply. Another factor
which has become more important is a means of disposal of the industrial wastes
from the industrial plant.
Many industries consider all of the other factors in their economic evaluation
of the proposed site and ignore the industrial waste problem until the plant is under
construction or in the final design stage. It then becomes a very critical problem
to find some method of disposal of the industrial waste. Generally, only when a
careful consideration of the industrial waste has been given ahead of the initial
design stage, or actual plant location, is it possible to find an economical method for disposal of the industrial waste. The purpose of this paper is to present the
factors which affected the location of one industry and the method used on a difficult and hard to treat industrial waste.
During the spring of 1961, a rug manufacturer was looking for a new site to
locate a wool scouring and yarn mill. The manufacturer was attempting to locate
in the Southeastern United States. There were several factors which required special consideration in the disposal of the waste from this mill.
The trade journals are full of articles on the treatment and problems from the
scouring of wool, but little is mentioned about the wide variations in the types of
wools themselves. In the manufacture of woolen rugs, the wool that is used has a
low initial grease content when compared with the wool used for blankets and
sweaters. A measure of the grease content is generally compared in the wool industry based on the shrinkage that is found during scouring. The shrinkage or loss
of weight during scouring for rug wools varies between 15 and 25 per cent. This
is fairly low when compared to the shrinkage on blanket and sweater wools which
is as high as 45 to 50 per cent. The actual grease content for rug wools will vary
between two and five per cent. There are other differences in the wool besides
the low grease content. The coarse heavy wool used for weaving of rugs has a
high grit content and high inorganic suspended solids content. This material accounts for a large part ofthe total shrinkage.
DESIGN CONSIDERATIONS
With reference to the specific mill in question, Dr. C.N. Sawyer of Met-
calf and Eddy, Engineers, made a detailed investigation of the pollutional load
from the process to be designed. Based on scouring approximately 50,000 lbs of
rug wool per day, it was estimated that with a five per cent grease content and a
26 per cent shrinkage value, that the waste effluent would contain 2,400 lbs of
grease, 4,200 lbs of suspended solids and 2,250 lbs of five-day BOD. The population equivalent based on BOD would be approximately 14,400 people. It was
estimated that 60,000 gals/day of water would be used in the nonionic detergent
scouring process.   In addition to the wool scouring waste, it was also estimated
- 413 -