One of the main influencing factors of eutrophication in rivers and lakes is ammonia nitrogen pollution. At present, the annual output of synthetic urea and ammonia in China is more than 40 million tons. The production of various types of ammonia nitrogen products allows enterprises to discharge large amounts of ammonia nitrogen wastewater. At the same time, the natural world will produce ammonia-nitrogen wastewater in the process of waste fermentation, and the total amount will exceed 100 million tons per year, which will have a greater impact on the natural environment.
The concentration of high concentration ammonia nitrogen wastewater is generally 0.5 g/L. Although there are various methods for effectively removing ammonia, for example, chemical methods include ion exchange, ammonia stripping, chemical precipitation, chlorination, electrodialysis, electrochemical treatment, catalytic cracking; physical methods include reverse osmosis, distillation, Soil irrigation; biological methods include nitrification and algae farming. However, the treatment method used for industrial wastewater must have the advantages of being suitable for wastewater water quality, stable treatment, economical, and convenient application. Therefore, the current techniques for ammonia nitrogen treatment are better: ammonia stripping, stripping, biological denitrification, ion exchange, and chlorination.
Mechanism of Magnesium Oxide Treatment of Ammonia Nitrogen Wastewater
Magnesium oxide is a metal oxide which, when dissolved in water, produces magnesium hydroxide which is a poorly soluble precipitate. In the ammonia nitrogen wastewater, NH4+ combines with OH- ions in Mg(OH)2 to form NH3, and in the case of stirring or aeration, ammonia nitrogen is discharged into the wastewater in the form of NH3, thereby achieving the purpose of removing ammonia nitrogen.
Secondly, magnesium oxide also plays a role in alkalinity. MgO+H2O⇌Mg(OH)2 Mg(OH)2+NH4+⇌NH3↑+H2O+Mg2+ is stirred or aerated, so that NH3 is separated from the wastewater, the equilibrium proceeds in the positive direction, and then MgO is dissolved to remove ammonia nitrogen. purpose.
In addition, temperature is also a factor influencing the reaction. As the temperature increases, the solubility of the gas decreases, so the higher temperature is more conducive to the volatilization of ammonia.
1 Adding magnesia, the effect of using ammonia to treat ammonia nitrogen wastewater is worse than that of aeration treatment under the same conditions.
2 The effect of magnesium oxide on the treatment of ammonia-nitrogen wastewater increases with increasing temperature.
3 At room temperature, the removal rate of ammonia nitrogen in ammonia-nitrogen wastewater increases with the increase of the amount of magnesium oxide added, and increases with the increase of aeration time. When the amount of magnesium oxide added was 2g/L and the aeration time was 2h, the ammonia nitrogen removal rate reached 99.66%, and the ammonia nitrogen removal effect was obvious.
However, with the further extension of the aeration time and the further increase in the amount of magnesium oxide added, the ammonia nitrogen removal rate is not significantly improved. It is concluded that the optimum condition for the treatment of ammonia-nitrogen wastewater by magnesium oxide is that the amount of magnesium oxide is 2 g/L and the aeration time is 2 h.
In short, magnesium oxide is inexpensive, and the remaining magnesium oxide after treatment of ammonia-nitrogen wastewater is also rarely dissolved in water and is discharged as a precipitate. Therefore, magnesium oxide does not form secondary pollution to wastewater, it is a green water treatment agent.
Fengcheng City Heqi Brucite Mining Co., Ltd., is an imports and exports mining company registered in 1998 in Fengcheng City of Liaoning Province. the company is located in Fengcheng City, Primarily engaged in processing minerals. The company property mainly manufactures magnesium hydroxide flame retardant and brucite powder. The export work is handling by DALIAN HEXIN NEW MATERIAL TECHNOLOGY CO., LTD.
Our annual output amount is up to 100,000 tons. Quality,Integrity, Innovation are our business ideas. Relying on quality products, good services, our company possess good reputation in the line.
"Business Integrity, Standardize Services, Sustainable development, Dedicated to Community" is the company’s Principles. During several years developing, the company possesses own mines and processing plants,It consists of the heqi brucite mine in Fengcheng city (reserves 3,000,000 tons, annual output is 100,000 tons).