Section Six
INDUSTRIAL WASTES
B. TEXTILES
76    COLOR REMOVAL FROM TEXTILE DYE WASTEWATER:
A CASE STUDY
Mark T. Kennedy, Engineer
Greeley and Hansen
Camp Springs, Maryland 20746
Joe M. Morgan, Associate Professor
Larry K. Benefield, Feagin Professor
Department of Civil Engineering
Auburn University, Auburn, Alabama 36849
A. Frank McFadden, Principal
McFadden Engineering Inc.
Mobile, Alabama 36619
INTRODUCTION
The textile industry has traditionally been one of the most important industries in the southern
United States, creating thousands of jobs. It is also a potential source of pollution which could have
disastrous effects on the ecology of the region. Happily, the textile industry as a whole has had an
excellent record of environmental regulatory compliance. But as pollution regulations become more
stringent, the textile industry is being forced to discharge effluents of increasing quality. One of the
pollution control parameters of concern to textile dyeing operations is color. This study demoastrates
color removal treatment processes using chemical, electrolytic, and polymer precipitation. Dye waste
effluents were provided by Lexington Fabrics Incorporated from their fabric dying facility previously
located in Lexington, Alabama.
Wastewater Treatment at Lexington Fabrics Inc.
Lexington Fabrics Inc.'s (LFI's) dye facility dyes fabric for a number of textile mills and was a
major industry in Lexington. In 1989 and 1990, the company was advised by the Alabama Department of Environmental Management (ADEM) during their permit renewal process that color removal
requirements would be incorporated in their revised NPDES permit. LFI's waste stream is typical of
dye facilities, having a BOD5 ranging from 300 to 750 mg/L, pH from 6 to 10.6, and TSS from 60 to
500 mg/L. In addition to process wastewater, the waste stream also contained a small sanitary flow
from the plant.
The wastewater treatment system consisted of 2 aerated lagoons operated in series, polymer addition for coagulation and color reduction, a rectangular clarifier with sludge recycling, and chlorina-
tion. Waste sludge was stored on site in a holding lagoon (see Figure 1). The first aerated lagoon
served to equalize the flow and the pH of the effluent waste stream from the plant.
The second lagoon was for BOD reduction. It was designed as an activated sludge process with a
hydraulic retention time of about 3-1/2 days at the highest permitted effluent flow (0.2 MGD).
Polymer was added before the clarifier to aid in color removal and settling. Sludge from the clarifier
was directed to either the second pond (for recycle), a conditioning tank, or a storage lagoon by means
of a tri-directional sump valve. Finally, chlorine was added for disinfection. The effluent flowed
through a chlorine contact channel, then down a cascade aerator to increase dissolved oxygen, and
finally into Mill Creek. The sludge conditioning tank was not in use at the time of this study and the
sludge holding lagoon was nearing the limit of its holding capacity.
47th Purdue Industrial Waste Conference Proceedings, 1992 Lewis Publishers, Inc., Chelsea, Michigan 48118.
Printed in U.S.A.
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