The textile printing and dyeing industry is a major emitter of industrial wastewater. Wastewater contains various dyes, slurries, surfactants, and other additives. The characteristics of wastewater are high organic concentration, complex composition, poor biodegradability, high and variable chromaticity, and large changes in water quality and quantity, making it a difficult industrial wastewater to treat.
The commonly used combination of biochemical treatment processes for printing and dyeing wastewater is summarized based on our company's years of experience in treating printing and dyeing wastewater: "hydrolysis acidification+contact oxidation" or "hydrolysis acidification+activated sludge" are relatively economical and applicable printing and dyeing wastewater treatment technologies. Using anaerobic or purely aerobic methods alone is not a good treatment method. Especially for the treatment of high and medium difficulty printing and dyeing wastewater, it will be difficult to meet the standards without a hydrolysis and acidification stage. Even for easily treatable denim washing and bleaching wastewater, adopting anaerobic treatment not only reduces treatment costs, but also reduces investment and facilitates operation.