Basic principles to be followed for wastewater in key industries

Since industrial wastewater has a great impact on the environment and is difficult to deal with, some basic principles should be followed in production and treatment. It is roughly summarized as the following 7 points: 1. Prioritize the use of non-toxic production processes to replace or reform backward production processes, and try to eliminate or reduce the production of toxic and harmful wastewater in the production process. 2. In the process of using toxic raw materials and producing toxic intermediate products and products, strict operation and supervision should be carried out to eliminate dripping, reduce loss, and adopt reasonable processes and equipment. 3. Wastewater containing highly toxic substances, such as some heavy metals, radioactive substances, high-concentration phenol, and cyanide waste water, should be diverted from other waste water in order to treat and recover useful substances. 4. Wastewater with a large flow rate and light pollution should be properly treated and recycled, and should not be discharged into the sewer, so as not to increase the load of urban sewers and urban sewage treatment. 5. Organic wastewater similar to urban sewage, such as food processing wastewater, sugar wastewater, and papermaking wastewater, can be discharged into the urban sewage system for treatment. 6. Some toxic wastewater that can be biodegraded, such as phenol and cyanide wastewater, should be treated first, and then discharged into urban sewers according to the allowable discharge standards, and then further biochemically treated. 7. Toxic waste water that is difficult to biodegrade should be treated separately and should not be discharged into urban sewers. The development trend of industrial wastewater treatment is to recycle wastewater and pollutants as useful resources or to implement closed loops. Identifying the Difficulties and Focusing on Overcoming Classified Disposal There are many industries in my country, and the waste water produced by each industry is different, and even the waste water produced by different processes in an industry is also different. Therefore, classifying wastewater, finding out the difficulties and key points of each category of wastewater treatment, will be able to treat industrial wastewater more effectively. Generally, industrial wastewater can be divided into three types according to different classification methods. The first is to classify according to the chemical properties of the main pollutants contained in industrial wastewater, that is, inorganic wastewater mainly contains inorganic pollutants, and organic wastewater mainly contains organic pollutants. For example, electroplating wastewater and wastewater from mineral processing processes are inorganic wastewater; wastewater from food or petroleum processing processes are organic wastewater. The second is classified according to the products and processing objects of industrial enterprises, such as metallurgical wastewater, papermaking wastewater, coking gas wastewater, metal pickling wastewater, chemical fertilizer wastewater, textile printing and dyeing wastewater, dye wastewater, tannery wastewater, pesticide wastewater, power station wastewater wait. The third is to classify according to the main components of the pollutants contained in the wastewater, such as acidic wastewater, alkaline wastewater, cyanide-containing wastewater, chromium-containing wastewater, cadmium-containing wastewater, mercury-containing wastewater, phenol-containing wastewater, aldehyde-containing wastewater, and oil-containing wastewater , Sulfur-containing wastewater, organic phosphorus-containing wastewater and radioactive wastewater. The first two classification methods in the three classifications do not involve the main components of the pollutants contained in the wastewater, nor can they indicate the harmfulness of the wastewater. The third classification method clearly reflects the composition of the main pollutants in the wastewater, which can indicate the harmfulness of the wastewater. Classification by the third method can clarify the focus and key of wastewater treatment, making wastewater treatment more targeted.