Treatment of high-ammonia-nitrogen wastewater
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Sources and main components of wastewater: In a process of hydrometallurgy, the ammonia nitrogen content in the initial material is around 15,000 mg/L. The reactor used for ammonia evaporation is a standard sealed enamel-lined tank (with a volume of approximately 6 cubic meters); steam is introduced into its jacket to heat the mixture and facilitate the reaction. The tank is equipped with mechanical agitators that stir the material, at a speed of around 130 revolutions per minute. The system used for absorbing ammonia gas is a Venturi vacuum spray system. The pH of the ammonia-evaporated solution is maintained at around 10, while the temperature remains between 90–95 degrees Celsius during the evaporation process (due to process requirements, the temperature must not exceed 100 degrees Celsius, as this could have negative effects on the material and compromise product quality). After about 3 hours of evaporation, the reaction is complete, and the ammonia nitrogen content in the resulting wastewater is around 1,500 mg/L. It is very difficult to reduce this value further ( attempts were made to continue evaporation for another 4 hours after the reaction was complete, bringing the total evaporation time to 7 hours, but the reduction in ammonia nitrogen levels was not significant enough; the ammonia nitrogen removal was not effective). Additionally, the wastewater from this process contains around 100–150 g/L of sodium chloride. With the existing equipment, it is possible to reduce the ammonia nitrogen level from 1,500 mg/L to around 100–150 mg/L, or additional equipment might be needed to achieve this goal. I would appreciate any suggestions you might have regarding better methods to achieve this reduction. Thank you
The usual simple ammonia evaporation process can be used; the ammonia evaporation tower is a desorption tower that releases ammonia gas dissolved in the circulating water. The working principle is as follows: Ordinary heat carrier, water vapor, is used as the heating agent, so that the equilibrium vapor pressure of ammonia at the surface of the circulating water is higher than the partial pressure of ammonia in the heat carrier. The gas and liquid phases come into counter-current contact, enabling mass and heat transfer; as a result, ammonia is gradually released from the circulating water. At the top of the tower, a mixture of ammonia vapor and water vapor is obtained, while at the bottom of the tower, relatively pure circulating water is produced. In short, the purpose of adding a base source is to convert fixed ammonium salts into volatile ammonium salts. ； When the ammonia nitrogen content in the wastewater entering the ammonia vaporization tower is around 5000 mg/L, the total ammonia content in the wastewater exiting the tower can be kept below 150 mg/L.
There are still solid materials in my solution, so it’s likely not possible to carry out the countercurrent gas-liquid contact you mentioned. If the solid materials need to be separated first, before proceeding with the ammonia evaporation as you suggested, well, that’s what needs to be done first. The temperature of the solution decreases during the separation process. For the ammonia evaporation process you mentioned, what temperature is required? If a high temperature is required, a heat source must be used to continue heating, which results in high energy costs and thus significantly increases the processing expenses. . To reduce ammonia nitrogen from 5000 mg/L to 150 mg/L, how long would it take in a vapor ammonia tower with a capacity of 10 cubic meters? .
You may try using the new resin developed by our company for removing ammonia nitrogen; if it’s convenient for you, please leave your contact information so we can discuss this issue further. Thank you
The energy consumption of this process is relatively high; the ammonia vaporization tower has a capacity of less than 10 m³. To meet that requirement, if it refers to the initial startup, it takes about half an hour to get everything operating properly
Our factory is similar to yours, but we use the stripping method; you can search for information on this method online. The cost of treating one ton of water is a little over 100 yuan
Our company can treat this kind of water; feel free to contact me at 15088793370 if needed
The energy consumption of this process is relatively high; the stripping method can be used, which is also cost-effective, and our company is capable of handling it