The water consumption of printing and dyeing industry is large, and it usually consumes 100 to 200t of water per printing and dyeing process of 1t textiles.
80% and 90% of them are discharged with printing and dyeing wastewater.
Common management methods are recycling and harmless treatment.
(1) waste water can be recycled according to water quality characteristics, such as separation of bleaching and boiling wastewater and dyeing and printing wastewater, the former can be washed by convection.
Use more water to reduce emissions.
(2) the recovery and utilization of lye is usually carried out by evaporation method. If the amount of lye is large, the amount of lye can be recovered by three-effect evaporation and the amount of lye is small.
(3) dye recovery.