Multiple Reuse of Residual Dyebaths for Cotton Dyeing with Reactive Dyestuffs: A Promising Technique for Environmental Sustainability

This research investigates the feasibility of reusing residual dyebaths for cotton dyeing with reactive dyes. For this, three reactive dyestuffs, namely C.I. Reactive Yellow 145, C.I. Reactive Red 238, and C.I. Reactive Blue 235, were used, separately and in mixtures, for dyeing cotton fabrics. After each dyeing, exhausted dyebaths were analyzed, reconstituted, and reused several times for various shades and mixtures. To evaluate the obtained results, two criteria were evaluated and analyzed such as dyebath exhaustion and color conformity of dyed samples. Analysis of the results showed that, in spite of the multiple reuses of dyebaths, the color of samples dyed with the reused dyebaths are comparable to those obtained from the initial dyebath with acceptable values of dyebath exhaustion and color conformity. As a result, this dyebath reuse method has then the potential to significantly reduce the use of water, dyes, and auxiliary quantities while ensuring that the performance of the dyeing process is maintained.