Printing and dyeing wastewater mainly contains dyes, slurries, dyeing, auxiliaries and fiber impurities, oils, acids, alkalis and inorganic salts, etc. Printing and dyeing wastewater also has the characteristics of complex composition, large discharge, deep color, high alkalinity, high organic content, low biodegradability, and large water quality changes. It is recognized as one of the main hazardous wastewater that are most difficult to be treated.
Compared with the traditional wastewater treatment technology, the MBR technology has lower pollutant content and higher stability. The treatment of printing and dyeing wastewater by MBR Membrane Bioreactor often requires multiple steps, which mainly includes three parts: filtration, degradation and denitrification.
Filtration mainly includes two parts: preliminary filtration and secondary filtration. Preliminary filtration is mainly used to simply remove high-quality components in wastewater, such as sediment, etc. This part realizes the preliminary purification of printing and dyeing wastewater. The entire process of secondary filtration is carried out in the anaerobic zone. The wastewater after preliminary filtration can fully react with activated sludge in this area, thereby further increasing the degree of wastewater purification.
Unlike filtration, the entire degradation process is jointly completed in the hypoxic zone and the aerobic zone. The organic matter in the wastewater is first gradually degraded to form small molecular substances. After that, the wastewater undergoes repeated denitrification reactions, so that the wastewater is deeply purified.
Membrane bioreactor technology not only has the advantages of traditional printing and dyeing wastewater treatment technology, but also has advantages that can not be achieved by traditional printing and dyeing wastewater treatment technology.