How to treat printing and dyeing wastewater produced by printing plant?

Printing and dyeing wastewater from printing plants usually contains a lot of chemicals such as dyes and inks, which pollutes the environment and water resources. In order to reduce the negative impact on the environment, it is necessary to treat printing and dyeing wastewater.

The following are several common methods for treating printing and dyeing wastewater:

Physical treatment method: large-particle impurities and suspended solids in wastewater are removed through physical processes such as filtration, precipitation and separation. This method can effectively reduce the turbidity and chromaticity of wastewater, but it can't remove dyes and organic pollutants.

Chemical treatment: chemical agents such as coagulants and oxidants are used to react with pollutants in wastewater and convert them into harmless substances. Common chemical treatments include chemical precipitation, chlorination and disinfection, ozone oxidation and so on.

Biological treatment: organic pollutants in wastewater are metabolized and decomposed into inorganic compounds or carbon dioxide and water by microorganisms. Common biological treatment technologies include activated sludge method, biofilm method and anaerobic digestion method.

Comprehensive treatment method: combining physical, chemical and biological treatment technologies to form a complete wastewater treatment system and achieve the best treatment effect. For example, chemical methods can be used to remove macromolecular organic matter, then biological methods can be used to treat the remaining organic matter, and finally physical treatment can be carried out to further purify water quality.

No matter which treatment method is adopted, it is necessary to monitor the quality of wastewater regularly to ensure that the treated wastewater meets the discharge standards and will not cause harm to the environment and human health.