What are the methods and significance of industrial sewage treatment?

Common industrial sewage treatment methods include physical treatment methods, biological treatment methods and chemical treatment methods. Sewage treatment can clean human food and is conducive to the long-term development of mankind. The following is a specific introduction to "methods and significance of industrial sewage treatment".

1、 Methods of industrial sewage treatment

1. The primary treatment adopts the physical treatment method, that is, the grid, screen, grit chamber, sedimentation tank, oil separation tank and other structures are used to remove the solid suspended solids and oil slick in the wastewater, preliminarily adjust the pH value and reduce the corruption degree of the wastewater. After primary treatment, the wastewater generally can not meet the discharge standard (BOD removal rate is only 25-40%). Therefore, it is usually the pretreatment stage to reduce the load of subsequent treatment processes and improve the treatment effect.

2. Secondary treatment uses biological treatment methods and some chemical methods to remove degradable organic matter and some colloidal pollutants in wastewater. After secondary treatment, the removal rate of BOD in wastewater can reach 80-90%, that is, the total amount of BOD can be less than 30mg / L. The water after secondary treatment can generally meet the agricultural irrigation standard and wastewater discharge standard, so secondary treatment is the main body of wastewater treatment. However, a certain amount of suspended solids, biodegradable dissolved organic matter, dissolved inorganic matter, nitrogen and phosphorus and other algae value-added nutrients remain in the secondary treated water, and contain viruses and bacteria. Therefore, it can not meet the higher discharge standards. If it is discharged into rivers with small flow and poor dilution capacity after treatment, it may cause pollution, and can not be directly used as the make-up water source of tap water, industrial water and groundwater.

3. The tertiary treatment is to further remove the pollutants that cannot be removed by the secondary treatment, such as phosphorus, nitrogen, organic pollutants, inorganic pollutants and pathogens that are difficult to be biodegraded. The tertiary treatment of wastewater is an "advanced treatment" method based on the secondary treatment, which further adopts chemical method (chemical oxidation, chemical precipitation, etc.) and physicochemical method (adsorption, ion exchange, membrane separation technology, etc.) to remove some specific pollutants. Obviously, the tertiary treatment of wastewater costs a lot, but it can make full use of water resources.

2、 Significance of sewage treatment

1. The decomposition of organic matter in sewage by microorganisms consumes a lot of oxygen, resulting in the death of organisms in water. Sewage treatment protects aquatic organisms, so as to protect the ecological balance;

2. Heavy metals in sewage enter the human table through the food chain and endanger human health. Sewage treatment cleans human food and is conducive to human long-term development.

3. The odor generated by sewage pollutes the atmosphere and endangers the environment. Sewage treatment is conducive to environmental protection.

The above is the introduction of "methods and significance of industrial sewage treatment". Please feel free to contact us if you have any questions.