Treatment of Wastewater from Cotton
Dyeing and Finishing Works for Reuse
MENACHEM REBHUN, Associate Professor
Sanitary Engineering
A. WEINBERG, Graduate Assistant
Chemical Engineering
NAVA NARKIS, Lecturer
Chemical Engineering
Technion - Israel Instutute of Technology
Haifa, Israel
INTRODUCTION
Textile dyeing and finishing mills are great water consumers and generate large
quantities of wastewater. The water shortage in Israel may limit expansion of existing
plants and development of new mills. In certain locations, such as in the south, the
water shortage is particularly acute and water costs are high.
The textile dyeing industry is facing difficult wastewater disposal problems.
The few mills located on the coast can dispose to the sea, this is connected with
considerable expenditures for conveying and proper sea outfall facilities. Most of the
plants are located inland, where almost no receiving waters are available. Although
utilization of wastewater for irrigation is widely practiced, the disposal of cotton
dyeing and finishing wastewater via this route is not possible because of their high
dissolved solids content mostly in the form of sodium salts. The present day possible
ways of disposal are dry river beds or evaporation ponds. Both methods may cause
ground water contamination. Disposal to dry river beds is unacceptable from esthetic
and sanitary point of view. Because of the large amounts of wastewater the area
required for evaporation ponds is large and may involve considerable expenses. The
wastewater disposal problems and the severe shortage of fresh water and its rapidly
rising cost have urged this investigation on recovery of the wastewater for in-plant
Water for textile dyeing and finishing should be in many respects of higher
quality then for domestic use. The whole wastewater from cotton dyeing and finishing is highly colored, alkaline, of high detergent and organic content. Treatment
processes reported were concerned with reduction of the pollutional load to make
the waste acceptable for discharge to receiving waters. To provide a high quality
product water for in-plant re-use it was considered that physico-chemical treatment
processes are required. Review of wastewater analysis and results of reported treatment processes did not encourage the use of this treatment for the whole wastewater.
However, it was evident that the great majority of the wastewater originates in
rinsings and washings. This water contains only a fraction of the pollutants generated
by a plant, while a relatively small volume of wastewater from dyeing and finishing
baths contains the bulk of pollutants. Therefore, when considering waste treatment
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