Printing and dyeing effluent is the effluent discharged from printing and dyeing factories that process mainly cotton, hemp, chemical fibers and their blended products. The volume of Printing and dyeing sewage is large, each printing and dyeing processing 1 ton of textiles consumes 100-200 tons of water, of which 80-90% becomes sewage.
Features
Printing and dyeing printing wastewater is one of the more difficult industrial wastewater treatment, it has high COD concentration, high chromaticity, high salinity, difficult biochemical degradation of organic matter and large changes in water quality and quantity with time (intermittent discharge of sewage) and other characteristics, Printing and dyeing wastewater treatment is highlighted by the removal of chromaticity and difficult to degrade organic matter problems.
Solution
Treatment of printing and dyeing printing wastewater is usually based on hydrolytic acidification - biological contact oxidation - biochar treatment process, which is a more mature process adopted in recent years in the treatment of Printing and dyeing wastewater. The purpose of hydrolysis acidification is to degrade some macromolecules and insoluble substances in Printing and dyeing wastewater with poor biochemical properties into small molecules and soluble substances through hydrolysis acidification, so as to improve biochemical properties and B/C value and create conditions for subsequent aerobic biochemical treatment. At the same time, the residual sludge from aerobic biochemical treatment is returned to the anaerobic biochemical section through the sedimentation tank for anaerobic digestion to reduce the residual sludge discharge of the whole system, i.e. to achieve its own sludge balance. The anaerobic hydrolysis and acidification tank and biological contact oxidation tank are installed with filler, which is a biofilm treatment; the biochar tank is installed with activated carbon and supplied with oxygen, which has the characteristics of both suspended growth and attached growth method, and the role of pulse water intake is to agitate the anaerobic hydrolysis and acidification tank.