The previous treatment process of bleaching and dyeing wastewater was biochemical treatment + coagulation precipitation + decolorizing agent sewage treatment facilities to treat a large number of ozone generator grey cloth pretreatment and dyeing wastewater discharged from the bleaching and dyeing workshop.

The above technical routes were jointly issued by the State Environmental Protection Administration and the National Development and Reform Commission in 2001 to guide the treatment of wastewater in China’s printing and dyeing industry, but the wastewater COD value is high, the color is large, and the organic matter that is difficult to degrade and the color of some printing and dyeing dyes is difficult to remove, which often cannot meet the requirements of the discharge standard COD≤100mg/L and the color ≤40(times). On the basis of many research experiments by scientific and technical personnel, it was decided that before biochemical treatment, the new technology of ozone strong oxidation should be pre-treated first, and then the in-depth treatment of biochemical degradation and ozone oxidation decolorization should be carried out, so that the remaining organic matter and chroma pollutants can be further removed, and the previously expensive decolorizing agent and coagulant can be eliminated. And achieve the standards of emissions and energy conservation and emission reduction requirements. On this basis, the continuous summary of experience for the realization of water recycling to achieve zero discharge laid the foundation for the realization of waste water resources, to create greater social and economic benefits.