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Reuse of the water and salt of reactive dyeing effluent after electrochemical decolorisation
Author(s) -
LópezGrimau Víctor,
GutiérrezBouzán María del Carmen,
Valldeperas José,
Crespi Martí
Publication year - 2012
Publication title -
coloration technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.297
H-Index - 49
eISSN - 1478-4408
pISSN - 1472-3581
DOI - 10.1111/j.1478-4408.2011.00343.x
Subject(s) - dyeing , chemistry , salt (chemistry) , effluent , wastewater , reuse , pulp and paper industry , sodium , electrolyte , nuclear chemistry , waste management , environmental engineering , environmental science , electrode , organic chemistry , engineering
In the dyeing of cellulose with reactive dyes, the addition of a high amount of electrolyte is required [50–80 g/l of sodium chloride (NaCl) or sodium sulphate (Na 2 SO 4 )]. The main goal of this work is the reuse of salt and water from exhausted dyebaths and washing effluents, which have been previously decolorised by means of an electrochemical treatment. Dyeings with three bifunctional reactive dyes (Navy Blue, Crimson and Yellow Procion H‐EXL) were carried out individually and in a trichromatic mixture. The reuse of the discoloured exhausted dyebath provided excellent red and yellow dyeings. Colour differences close to the quality control limit (Δ E CMC(2:1) ≤ 1) were obtained in the blue and trichromatic dyeings. An average recovery of 70% of water and 60% of salt was achieved with the reuse process. High‐quality dyeings were also obtained with the discoloured first‐washing bath. In this case, 15% of salt and almost 100% of water were recycled.