Removing colour from textile effluent
Why dissolved dye passes through ordinary treatment, and how a decolorant and a flocculant work together to clear it.
Why colour stays
Dye that does not fix on the fabric leaves in the wastewater. Reactive, acid and direct dyes in particular stay dissolved, so coagulation alone leaves the effluent coloured.
How a decolorant works
SunDec SC05 is a cationic dicyandiamide resin. Its positive charge combines with negatively charged dye molecules to form insoluble complexes.
Then flocculate
Those complexes are fine; a coagulant and a flocculant gather them into settling flocs. In textile plants the flocculant is usually Cationic HQ or Cationic MQ.
Order of dosing
Decolorant and coagulant first, with mixing; flocculant last, in the gentle mixing zone before the clarifier.
Test on your colour
Dye mixes change with production. Jar-test decolorant and polymer together on a current sample.
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