Evaluation of operational parameters from a microfiltration system for indigo blue dye recovery from textile dye effluent

This study aims to evaluate the use and operational parameters for microfiltration system (MF) for recovery of insoluble indigo blue present in the dye bath water of the cotton yarn, in order to reuse the pigment and water washing. The results showed that MF process is a promising technology for the recovery of insoluble indigo blue presents in a synthetic wastewater. The longitudinal module, when compared with the submerged module, presented a better performance showing removal efficiency of color and chemical oxygen demand (COD) of 99 and 94%, respectively. The dye recovery operation was performed at low pressure, specifically 0.3bar, value determined by analysis of critical flux. The process was carried out under a laminar flow with Reynolds values of 1,900 and 2,850 and a turbulent flow with Reynolds values of 3,800 and 4,700 that achieved a recovery rate of 89.7% under minimal fouling conditions.