Page 78 - Industrial Wastewater Treatment, Recycling and Reuse

Industrial Wastewater Treatment, Recycling, and Reuse: An Overview 55

Thailand. DyStar, Ciba, Specialty Chemicals, and Clariant are some of the
world’s leading manufacturers of dyes. Regulatory barriers have nearly
stopped progress in opening fundamentally new dyestuff manufacturing
facilities. The manufacturers are, however, continuing to add to their pro-
duction of reactive and specialty dyes. Among the developing nations,
China’s production of dyes and organic pigments is increasing at a fast rate.
In 2004, the production share of the United States and Europe was reported
to be 24% and 22% respectively.

1.5.2.3 Dye Wastewater Treatment: Overview and Recommendations
Typically, the dye industry handles different types of dyes, most prominent of
which are acid and direct dyes, disperse dyes, sulfur dyes, reactive dyes, and vat
dyes, while the dye intermediate industry produces H-acid, vinyl sulfone, and
gamma acid as the main products. A conventional water pattern in small- to
medium-scale dyestuff manufacturers is shown in Figure 1.18.

Reactive dyes Acid and direct dyes
Raw
Raw
material
material T/T, 1.97
T/T, 1.5
Liquid
Liquid Process effluent Process
effluent water T/T, 14 water
T/T, 30.9 T/T, 33.8 T/T, 16

Pigment Dyes general

Raw Raw
material material
T/T, 5.7 T/T, 12.2
Liquid Liquid
effluent effluent
T/T, 23.6 Process T/T, 26.5 Process
water water
T/T, 44.2 T/T, 32

Figure 1.18 Typical water and wastewater scenario in small scale dyes industry.