Printing and dyeing wastewater refers to the wastewater containing organic matter, acid, alkaline, salt and many harmful substances with high chroma discharged from the printing and dyeing industry in the production process. Direct discharge of printing and dyeing wastewater will cause great harm to the surrounding environment and human health, so it is necessary to effectively treat printing and dyeing wastewater. The following will introduce some methods to solve the problem of printing and dyeing wastewater and printing and dyeing wastewater treatment equipment.

First, reduce the amount of printing and dyeing wastewater

Reducing the amount of printing and dyeing wastewater is an important measure to solve the problem of printing and dyeing wastewater. This method mainly has the following aspects:

1. Save water: printing and dyeing industry is one of the industries with large water consumption, and the production of printing and dyeing wastewater can be reduced by saving water.

2. Improve the printing and dyeing production process: new production processes can be used to reduce the generation of wastewater, such as low-temperature dyeing, using a small amount of dyes and chemicals.

3. Reduce the number of cleaning of printing and dyeing equipment: in the production process, the equipment needs to be cleaned regularly, and the wastewater discharged after cleaning contains a higher concentration of harmful substances. Therefore, waterless cooling cleaning and organic solvent cleaning can be used to reduce the number of cleaning.

Second, dyeing wastewater treatment

1. Advanced treatment: The printing and dyeing wastewater after preliminary treatment contains certain organic substances and pigments, which need to be further treated. Commonly used advanced treatment methods are biochemical methods (aerobic and anaerobic methods), physical and chemical methods.

Biochemical method refers to the process of converting organic substances and pigments into harmless substances through microorganisms, including aerobic method and anaerobic method. Aerobic method is suitable for the treatment of printing and dyeing wastewater with low concentration of organic matter, suitable for the environment of sufficient oxygen, and anaerobic method is suitable for the treatment of printing and dyeing wastewater with high concentration of organic matter, which needs to be treated under anaerobic conditions.

Physicochemical method refers to the conversion of harmful substances in printing and dyeing wastewater into harmless substances through chemical reaction, adsorption, precipitation, filtration, oxidation and other methods.

2. General treatment: For the initial discharge of printing and dyeing wastewater, usually using precipitation, filtration, screen and other ordinary treatment methods.

The precipitation method is to precipitate the suspended particles and colloidal substances in the printing and dyeing wastewater by gravity.

The filtration method is to filter the suspended particles in the wastewater through the filtration medium (such as quartz sand, coal cinder, ceramic particles, carbon filter materials, etc.).

The screen method is to screen the solid substances in the wastewater through the screen (such as metal mesh, fine mesh, etc.).

3. Comprehensive treatment: In the process of printing and dyeing wastewater treatment, the comprehensive use of a variety of treatment methods, such as the combination of biochemical and physico-chemical treatment, can reduce the concentration of harmful substances in the wastewater and achieve better wastewater treatment results.

Printing and dyeing wastewater treatment equipment

Third, printing and dyeing wastewater treatment equipment

1. Biological treatment equipment: Biological treatment equipment mainly includes activated sludge process, downstream biofilm reactor, moving bed reactor and other biological treatment equipment. These devices can effectively remove organic matter and color in wastewater, with high yield, stable operation, energy saving and environmental protection.

2. Physical and chemical treatment equipment: physical and chemical treatment equipment mainly includes sedimentation tanks, filters, adsorbers, etc. These devices can effectively remove the color and suspended substances in the wastewater, and are suitable for large quantities of wastewater treatment.

3. Comprehensive treatment equipment: Comprehensive treatment equipment mainly uses the combination of a variety of treatment methods, such as aerobic and anaerobic combination, biochemical and physicochemical combination. Comprehensive treatment equipment can balance the adaptability between various treatment methods in a long time, and can treat a variety of harmful substances in wastewater.

In short, to solve the problem of printing and dyeing wastewater requires a series of measures and equipment. The harm of printing and dyeing wastewater to environment and human health can be effectively reduced by reducing the amount of printing and dyeing wastewater, conducting deep treatment and general treatment, and adopting equipment for printing and dyeing wastewater treatment.