REUSE IN TEXTILE BLEACHING PROCESSES OF EFFLUENTS FROM DYEING WITH REACTIVE BLACK DYES DECOLORED BY THE FENTON METHOD

Abstract

Textile effluents from reactive black dyes, decolorized using the advanced Fenton oxidation method, were reused in cellulosic fiber exhaustion bleaching processes. Textile black reactive effluents were collected, provided from two recipes of reactive blacks; Corafix Black SD (Black SD) and Corazol Black B 133 % (Black 5), simulated and real, due to being decolored by the Fenton treatment. The discoloration was monitored using UVvisible spectrophotometry, the optimal proportions of Fenton reagent (Fe (II) salt (g) / H2O2 (mL)) were determined: 0,0156 g / mL and 0,0251 g / mL with 90 minutes of reaction time, and optimal treatment pH of 3,70 and 3,88 for textile effluents from dyeing with Corafix Black SD and Corazol Black B 133 % dyestuffs respectively. The discolored effluents were characterized, adequated, and used in bleaching of cellulosic fabrics. Textiles with a degree of whiteness of 74,73 °Be and 73,41 °Be were obtained, similar to the substrate bleached with soft water (76,61 °Be). The reflectance curves were compared with the Datacolor SF550 spectrophotometer, hydrophilicity and capillarity according to standardized methods. Finally, it was concluded that the Fenton treatment is viable for this type of reactive black effluent since bleached substrates with properties similar to bleaching with soft water were obtained