Dye House Water Treatment

[teknovation]

Which is the most effective Dye House water treatment process. Is there any solution to total color removal and can the water be re-usable for dye house.

 

[250380]

OZONE IS THE BEST WAY HOW TO TREAT COLLOR. AFTER OZONATIOAN AND MECHANICAL FILTRATIAN WATER CAN BE REUSED. i HAVE SEEN RESULTS OF OZONATION, THEY ARE WERRY GOOD.

 

[kenvlach]

Dye can be recovered and rinsewater re-used via reverse osmosis. This is a good option if you have one primary color (e.g., blue for jeans mfr. or black for aluminum anodizers). Obviously, a separate RO unit would be needed for each color in order to recycle dye, but only one RO if just recycling the water. Also, for dye recovery, you would need to use DI water for both the dye solution and drag-out rinse to avoid buildup of impurities. The dye recovered from the rinse goes back into the dye solution. See an example where dye usage was cut by more than 50%, plus all water recycled, for a 2-year payback on investment, at

http://www.epa.gov/Region9/cross_pr/merit/osmosis.pdf

Besides ozonation, which I agree is good for this application, you can use electrocoagulation to break down the dye molecules and get good settling of metals in a clarifier or settling tank. Supplemental filtration,e.g., RO, would be beneficial to remove dissolved byproducts, etc. I have tested a number of organic and organometallic dyes, and only had problems with one highly stable black dye from Clariant (the same dye requires several hours treatment with hypochlorite for traditional breakdown).

Electrocoagulation has the advantage that it doesn’t generate Cr⁺⁶ as some oxidation processes do when breaking down Cr-containing dyes. Electrocoagulation will actually oxidize dye and reduce Cr⁺⁶ simultaneously.