In recent years, with the improvement of environmental protection awareness and the continuous strengthening of national environmental protection policies, all walks of life have higher and higher requirements for environmental protection. Among them, printing and dyeing industry is a high degree of pollution industry, printing and dyeing wastewater has been the difficulty of environmental protection. However, the emergence of zero discharge technology for printing and dyeing wastewater has reduced the pressure on environmental protection for printing and dyeing enterprises, and has also made important contributions to the protection of the natural environment.

The so-called zero discharge system of printing and dyeing wastewater refers to the treatment of wastewater generated in the printing and dyeing process through a series of technical means and equipment to achieve the purpose of no discharge of wastewater. Its main characteristics are: high efficiency, energy saving, pollution-free emission.

The main technologies of printing and dyeing wastewater zero discharge system include: pretreatment technology, physical treatment technology, chemical treatment technology, biological treatment technology, etc.

Pretreatment technology is the first step of printing and dyeing wastewater treatment, mainly through coagulation, precipitation, filtration and other ways to remove suspended particles, fats, pigments and other pollutants in sewage.

Physical treatment technology refers to the further removal of organic and inorganic substances in wastewater through physical filtration, adsorption, membrane separation and other methods to achieve the purpose of gradually improving water quality.

Chemical treatment technology is mainly through the addition of chemical agents, so that the pollutants in the printing and dyeing wastewater chemical reaction, the formation of precipitates or gases, so as to achieve the reduction and removal of pollutants in the wastewater. Common chemical treatment techniques include: oxidation, precipitation, neutralization, etc.

Biological treatment technology is the key technology of printing and dyeing wastewater zero discharge system, which realizes the degradation of organic matter through the role of microbial flora, converts organic matter in sewage into carbon dioxide and water, so as to achieve the purpose of zero discharge. Biological treatment technology includes: aerobic treatment, anaerobic treatment, mixed treatment and so on.

In addition, the printing and dyeing wastewater zero discharge system also needs to be equipped with wastewater treatment equipment, including sludge dewatering machine, filter, membrane separator, aerator and so on. These equipment can better cooperate with various wastewater treatment technologies to achieve zero discharge of printing and dyeing wastewater.

In short, the printing and dyeing wastewater zero discharge system is a comprehensive technology, and its successful realization needs the efforts of the majority of environmental science and technology workers. In the future, with the continuous upgrading and improvement of technology, the printing and dyeing wastewater zero discharge system will be promoted and applied in more printing and dyeing enterprises, making important contributions to the realization of environmental protection and ecological harmony.