Exploring reuse of industrial wastewater from exhaust dyebaths by solar-based photo-Fenton treatment

The aim of the research under discussion in the present paper is to study the decolorization and mineralization of textile industrial wastewaters from exhaust dyebaths by means of a solar photo-Fenton treatment. The exhaust dyebaths were grouped according to the fibers and dyeing recipes used, so as to verify the effectiveness of the photo-Fenton treatment on each dyeing process separately. Next, the results previously achieved were compared to those obtained by mixing all the exhaust baths together, as is common practice when treating the industrial textile effluents from dyeing and finishing procedures. After their neutralization and filtration, photo-Fenton-treated exhaust dyebaths and mixtures were reused to prepare laboratory dyeing samples. These techniques on the reuse of wastewaters were tested on several fibers by using the same dyeing procedure that was originally applied, as well as in different dyeing processes and for most fiber types. The results achieved showed that the reutilization of the aforementioned effluents, either in new exhaust dyebaths or in some other textile industrial operations, was of some considerable importance. Water consumption would be significantly reduced as well as the wastewater levies for the firms. Furthermore, the contaminating effect of the industrial effluents to be dealt with would be also diminished, reaping environmental and economic benefits.