How to deal with industrial sewage, common sewage treatment methods in factories?

Industrial sewage must contain a lot of harmful substances, so it must be removed when it is treated!

There are three general treatment methods: physical, biological and chemical.

Physical method: It mainly uses physical action to separate the insoluble substances in the sewage, and does not change the chemical properties during the treatment process. Commonly used are gravity separation, centrifugal separation, reverse osmosis, air flotation, etc.

The physical treatment structure is relatively simple and economical, and is used in the case of large water capacity, strong self-purification capacity and low sewage treatment degree requirements in villages and towns.

Biological method: The metabolic function of microorganisms is used to decompose and oxidize the organic matter in the dissolved or colloidal state of sewage into stable inorganic substances, so that the sewage can be purified. Commonly used are activated sludge method and biofilm method. The biological method is more highly processed than the physical method.

Chemical method: It is a method that uses chemical reaction to treat or treat dissolved substances or colloidal substances in sewage. Commonly used are coagulation method, neutralization method, redox method, ion exchange method, etc.

The chemical treatment method has good treatment effect and high cost, and is mostly used as effluent after biochemical treatment for further treatment to improve the effluent quality.

Industrial wastewater includes production wastewater and production sewage, which refers to the wastewater and waste liquid generated in the industrial production process, which contains industrial production materials, intermediate products, by-products and pollutants generated in the production process that are lost with water.

There are usually three types:

The first is classified according to the chemical properties of the main pollutants contained in industrial wastewater, which is mainly inorganic wastewater and organic wastewater. For example, the wastewater from electroplating and mineral processing is inorganic wastewater, the wastewater from food or petroleum processing is organic wastewater, and the production process of printing and dyeing industry is mixed 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, tanning wastewater, pesticide wastewater, power station wastewater, etc. The third is classified according to the main components of pollutants contained in 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, oil-containing wastewater, sulfur-containing wastewater, organic phosphorus-containing wastewater and radioactive wastewater. The first two classifications do not address the main components of the pollutants contained in the wastewater and do not indicate the hazard of the wastewater.

The third classification method can be divided into acidic wastewater, alkaline wastewater, phenol-containing wastewater, chromium-containing wastewater, organic phosphorus-containing wastewater and radioactive wastewater according to the main components of pollutants contained in wastewater.

Treatment principles: 1) Give priority to the use of non-toxic production processes to replace or reform backward production processes, and eliminate or reduce the generation of toxic and harmful wastewater in the production process as much as possible.

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 leakage, reduce loss, and adopt reasonable processes and equipment as much as possible.

3) Wastewater containing highly toxic substances, such as wastewater containing some heavy metals, radioactive substances, high concentrations of phenol, and cyanide, should be separated from other wastewater for treatment and useful substances.

4) Wastewater with a large flow rate and light pollution should be properly treated and recycled, and should not be discharged into sewers, 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 biodegradable toxic wastewater, such as phenol and cyanide wastewater, should be treated first, and then discharged into the urban sewer according to the allowable discharge standard, and then further biochemical treatment.

7) Toxic wastewater containing refractory biodegradation should be treated separately and should not be discharged into urban sewers. The development trend of industrial wastewater treatment is to use wastewater and pollutants as useful resources** or implement closed-circuit circulation.

This is related to the nature of industrial wastewater, which includes toxic elements, suspended solids, etc. In general, when the industrial sewage treatment is recycled, the treatment equipment is more complicated.

I can tell you the specific private message.

1.Electrolysis: The electrochemical reaction in the electrolyzer is used to treat various pollutants in wastewater.

Dissolved contaminants in industrial wastewater can form precipitates or gas spills through redox reactions in electrolysis. Electrolysis includes electrolytic redox, electrolytic air flotation and electrolytic coagulation, and is mainly used to treat chromium-containing and cyanide-containing wastewater.

2.Chemical precipitation method: soluble chemical agents (i.e., precipitants) are added to the wastewater, and the inorganic pollutants in the ionic state in the water are chemically reacted to generate insoluble or insoluble compounds in water, precipitate and precipitate, so that the wastewater can be purified.

Chemical precipitation is mostly used to remove heavy metal ions in wastewater, such as mercury, chromium, lead, zinc, etc. Chemical precipitation methods include hydroxide precipitation, sulfide precipitation, barium salt precipitation, and ferrite precipitation.

3.Disinfection and sterilization: Disinfection and sterilization technology is mainly used for advanced treatment of water.

Disinfection and sterilization mainly use chlorine, hypochlorite, chlorine dioxide, ozone, ozone-ultraviolet rays, etc. Chlorine dioxide is used for water treatment and disinfection and has received a lot of attention in recent years, mainly due to the fact that it does not react with humus in water to produce halogenated hydrocarbons. Ozone disinfection is considered to be an effective disinfection method to replace chlorination in the water treatment process, because ozone first has a strong bactericidal power, and secondly, it oxidizes and decomposes organic matter quickly, so that the mutagenicity of water after disinfection is minimized.

Generally speaking, the common sewage treatment process in the factory is: interception well, coarse grid, sewage pump, fine grid, grit tank, biochemical tank, final sedimentation tank, D-shaped filter, disinfection, and final effluent.

There are two main methods of sewage treatment: one is the physical method and the other is the chemical method. The two are often used in combination!

It depends on whether it is industrial production sewage or domestic sewage, if you only want to use a fixed treatment method, it is basically not up to standard. For industrial wastewater treatment methods, it is recommended that you use a combination of treatment technologies. The principles of the industrial sewage treatment method are:

Targeted processing, a variety of combination processing.

The water first flows through the grid to remove large impurities and then enters the sedimentation mixing tank. In the sedimentation conditioning tank, the pH value of the wastewater is lowered to an appropriate level by the automatic pH value adjustment system, and the sediment is carried out during the hydraulic retention time to remove the impurities of the enlarged lead mold. At the same time, the sedimentation conditioning tank has the fivefold functions of adjusting pH value, precipitation, homogenization and homogenization, acidification, and reducing sales and excitation liqueolysis.

The wastewater of the regulating tank is lifted to the first reaction chamber of the sewage treatment equipment through the submersible sewage pump. In this reaction chamber, a coagulant is added through a dosing system to further coagulate and precipitate the wastewater. The reaction chamber is equipped with an inclined sedimentation plate device, which promotes the full mixing reaction of wastewater and coagulant and improves the sedimentation effect, eliminating the need for a mixer and saving the power consumption of operation.

After the coagulation and sedimentation of the reaction chamber, many suspended solids and some COD pollutants in the wastewater can be removed, and the water quality can be significantly improved. The wastewater clarified by precipitation enters the second reaction chamber of the sewage treatment equipment through the upper water distribution device. The chamber is equipped with a biofilm packing layer.

The aeration system can provide enough oxygen for aerobic microorganisms and create a good aerobic environment, aerobic microorganisms can grow and multiply rapidly, and the organic matter in the sewage is further absorbed and degraded by microorganisms. When the wastewater flows through the biofilm filler layer, a large number of aerobic microorganisms contained in it can quickly adsorb on the surface of the filler, multiply, and quickly form a biofilm. This biofilm has strong biochemical activity.

When the wastewater flows through, the biofilm adsorbs and degrades the organic matter in the wastewater. After the treatment of the equipment, the water quality of the wastewater has basically reached the treatment standard.