Views: 6 Author: Xicheng Ep Ltd Publish Time: 2022-02-17 Origin: Xicheng Ep Ltd
How to reduce factory air pollution? First of all, it depends on the specific composition of the exhaust gas. If there is dust, electrostatic precipitator should be used first to recover the useful elements that can be used. Then, if the acid gas such as CO2 and SO2 needs to be absorbed by excess lime water, that is, CaOH solution; Alkaline gases such as NH3 are generally dissolved in water, and then there are other exhaust gases, such as CO, methane and other gases that need to be ignited. Specific analysis and treatment should be carried out according to the type of waste gas on site. For example, if acid oxides such as carbon dioxide and sulfur dioxide are treated, sodium hydroxide solution is used. If there is particulate matter, dust removal, pulse dust removal or welding fume purification is required. If it is only organic waste gas from vocs, it is necessary to use a photolysis type waste gas purification device or low-temperature plasma waste gas treatment equipment to purify the waste gas, and then discharge it at high altitude .
Common methods for treating factory waste gas include biological decomposition method, activated carbon adsorption method, plasma method, wet spray absorption method and UV photolysis purification method. Its wet spray absorption purification technology has been verified by actual engineering in terms of investment cost, operating cost, no secondary pollution, purification efficiency, etc., and has the incomparable advantages of conventional deodorization technology. The following is a brief introduction to these five commonly used factory waste gas treatment methods:
1. Microbial decomposition method: The biological decomposition method uses the circulating water flow to contain the pollutants in the odorous gas in the water, and then cultivates microorganisms in the water culture bed to degrade the pollutants in the water into low-harm substances, and the deodorization efficiency can reach 70% However, affected by the activity of microorganisms, the cultured microorganisms can only process one or several gases with similar properties. In order to improve the treatment efficiency and stable operation, it is necessary to frequently add chemicals, control PH value, temperature, etc., so the operating cost is relatively high. , and more labor is invested, and once the organism dies, it will take a long time to re-cultivate;
2. Activated carbon adsorption method: The activated carbon adsorption method uses the developed internal void structure of activated carbon and the principle of huge specific surface area to adsorb the odorous gas molecules passing through the activated carbon pool. The initial treatment efficiency can reach 65%, but it is very easy to be saturated, usually for several days. That is to say, it fails and needs to be replaced frequently, and it is necessary to find a treatment method for waste activated carbon. The operation and maintenance cost is very high. It is suitable for low concentration and large air volume gas, and has obvious effect on alcohols and fats, but the effect of exhaust gas with high humidity is not obvious. , and it is easy to cause secondary pollution of the environment;
3. Plasma method: The plasma method uses the principle of using high-voltage electrodes to emit ions and electrons to destroy the structure of malodorous molecules, bombarding malodorous molecules in the exhaust gas, thereby cracking the malodorous molecules, and has a significant purification effect on low-concentration malodorous gases. It can handle a mixture of gas that is fully composed of a variety of odors, and it is not affected by humidity and has no secondary pollution; however, it consumes a lot of electricity and needs to be cleaned. Flammable and explosive gas can easily cause explosion;
4. Wet spray absorption method: The acid mist exhaust gas is introduced into the wet scrubber through the air duct. After passing through the packing layer, the exhaust gas and the sodium hydride absorbent are fully contacted with the gas and liquid to absorb and neutralize the gas. After purification, the acid mist exhaust gas is dehydrated and removed by the soot board, and then discharged into the atmosphere by the fan. After the bottom of the tower is pressurized with a water pump, the absorbent is sprayed down from the top of the tower, and then recycled to the bottom of the tower. The purified acid mist exhaust gas meets the national emission standard.
5. UV photolysis purification method: UV photolysis purification method uses UV ultraviolet rays. In the photolysis purification equipment, the molecular chain of oxidized malodorous substances is cracked, the material structure is changed, and the macromolecular pollutants are cracked and oxidized into low-molecular-weight harmless substances. Its deodorization efficiency can reach 99%, and the deodorization effect greatly exceeds the emission standard for malodorous substances (GB14554-93) promulgated in 1993. It can handle ammonia, hydrogen sulfide, methyl mercaptan, methyl sulfide, benzene, styrene, carbon disulfide, dimethyl sulfide. Disulfide and other high-concentration mixed gases, the internal light source can be used for three years, the equipment life is more than ten years, the purification technology is reliable and very stable, the purification equipment does not require daily maintenance, and can be used normally only by connecting to the power supply, and the operating cost is low , no secondary pollution.
From this point of view, if the waste gas treatment effect produced by the factory needs to meet the standard, it is more cost-effective to use the PP wet scrubber system. The wet scrubber exhaust gas purification device can be used in food processing plants, meat processing plants, slaughterhouses, poultry, etc. Deodorization and purification of organic and inorganic malodorous gases such as feed farms, paper mills, sewage treatment plants, garbage transfer stations, and manure treatment; it can also be used in oil refineries, rubber factories, leather factories, printing factories, chemical factories, Chinese and Western medicine factories , Deodorization and purification of organic and inorganic odorous gases such as metal foundries, plastic recycling plants, spraying solvents, etc.