TREATMENT OF DYE BATHS BY A MEMBRANE PROCESS FOR THE PURPOSE OF THE REUSE OF THE WATER AND NACI IN THE PROCESS

摘要

The present invention relates to a process for the treatment and the recovery in value of baths for the dyeing of cellulose fibres with reactive dyes comprising a prefiltration, a neutralization, a nanofiltration and a reverse osmosis. The following are reused at the end of the treatment: on the one hand, colourless water comprising the inorganic salts necessary for a new dyeing with reactive dyes; on the other hand, pure water which will be used either during the nanofiltration or for other operations, such as washing or rinsing the dyed material. Furthermore, an aqueous solution of very low volume, mainly comprising hydrolysed reactive dyes and dye additives, is recovered. This results in savings in water, in a drastic reduction in the salinity of the effluents and in a simplification in the treatment of the effluents originating from the other baths necessary for the processing of cotton dyed with reactive dyes, in short in a significant reduction in pollution of the environment.