Reuse of stained wash water for washing fabric after dyeing

Summary

The processes of aqueous work up of the fabric used at the textile enterprise «Svitanak» OJSC were studied during the fabric preparation, dyeing and subsequent washing. The quality of wash water at various stages of washing the fabric after dyeing was studied by such indicators as the color intensity by dilution rate, COD, permanganate index, foaming capacity and pH. Experimental data are presented that prove the possibility of using ozone for the purification of the wash water mixture from the last six fabric washings after dyeing to the requirements to the quality of water supplied to the dye-finishing processes. An approximate economic calculation has been performed that proves a high economic effect of establishing the reuse of wash water regenerated with ozone for washing fabric after dyeing.

Key words

ozonization , chromaticity , permanganate oxidizability , filter washings reuse , countercurrent , textile industry , fabric dyeing , apparatus of batch operation , color intensity by dilution rate

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The use of ozone to reduce the color intensity of textile wastewater

Summary

The relevance of the development of effective methods for the destruction of dyes in the wastewater of consumer goods industry is increasing due to the severization of the requirements to the aquatic environment protection. The mechanisms of interaction of ozone with unsaturated and aromatic organic compounds in aqueous solutions are considered. Special focus is placed on the interaction of ozone with azo dyes. A detailed procedure for carrying out experimental studies is given, that provide for accurate dosing of ozone into the reaction mixture. The data of experimental studies are presented that are indicative of the effectiveness of using ozone for the destruction of dyes in model solutions. A comparison was made of the effectiveness of using ozone compared to the reducing agents to reduce color intensity of dye solutions. Specific doses of ozone have been preliminarily determined to reduce color intensity of solutions of some synthetic dyes to standard values.

Key words

wastewater , ozone , textile industry , azo dyes , color intensity