How to treat high ammonia nitrogen wastewater?

At present, with the rapid development and growth of industries such as fertilizers and petrochemicals, the resulting high-ammonia nitrogen wastewater has also become one of the constraints on the development of the industry; ammonia nitrogen is one of the important causes of pollution, especially the pollution caused by high-concentration ammonia nitrogen wastewater. Therefore, the economic control of high-concentration ammonia nitrogen wastewater pollution has also become an important topic for current environmental protection workers to study, and has received great attention from industry insiders.

The general formation of ammonia nitrogen wastewater is caused by the coexistence of ammonia water and inorganic ammonia. Generally, the main source of ammonia nitrogen in wastewater with a pH above neutral is the joint action of inorganic ammonia and ammonia water. Under acidic conditions, ammonia nitrogen in wastewater is mainly caused by inorganic ammonia. There are two main types of ammonia nitrogen in wastewater, one is ammonia nitrogen formed by ammonia water, and the other is ammonia nitrogen formed by inorganic ammonia, mainly ammonium sulfate, ammonium chloride, etc.

How to treat high-ammonia nitrogen wastewater? The traditional method generally adopts physical and chemical methods:

1. Stripping method. Under alkaline conditions, a method of separation using the gas-liquid equilibrium relationship between the gas phase concentration and the liquid phase concentration of ammonia nitrogen is generally believed to be related to humidity, pH, and gas-liquid ratio.

2. Zeolite deamination method. The cations in zeolite are exchanged with NH4+ in wastewater to achieve the purpose of denitrification. The application of zeolite deamination method must consider the regeneration of zeolite, which usually includes regeneration liquid method and incineration method. When the incineration method is used, the generated ammonia must be treated.

3. Membrane separation technology. A method of removing ammonia nitrogen using the selective permeability of the membrane. This method is easy to operate, has a high ammonia nitrogen recovery rate, and no secondary pollution. For example: gas-water separation membrane removes ammonia nitrogen. Ammonia nitrogen exists in dissociation equilibrium in water. As the pH increases, the proportion of ammonia in the NH3 form in water increases. At a certain temperature and pressure, the gaseous and liquid states of NH3 reach equilibrium. According to the principle of chemical equilibrium movement, all equilibrium in nature is relative and temporary. Chemical equilibrium can only be maintained under certain conditions. "If the conditions of the equilibrium system are changed, such as concentration, pressure or temperature, the equilibrium will move in the direction that can weaken this change." Following this principle, the following design concept was carried out. On one side of the membrane is high-concentration ammonia nitrogen wastewater, and on the other side is acidic aqueous solution or water. When the temperature on the left side T1>20℃.PH1>9.P1>P2 maintains a certain pressure difference, the free ammonia NH4+ in the wastewater will become ammonia molecules NH3, and diffuse to the membrane surface through the raw liquid side interface. Under the action of the partial pressure difference on the membrane surface, it passes through the membrane pores and enters the absorption liquid, and quickly reacts with H+ in the acidic solution to form ammonium salts.

4. MAP precipitation method. It mainly uses the following chemical reaction: Mg2++NH4++PO43-=MgNH4PO4. In theory, phosphate and magnesium salts are added to wastewater containing high concentrations of ammonia nitrogen in a certain proportion. When [Mg2 + ][NH4+][PO43 -]>2.5×10–13, magnesium ammonium phosphate (MAP) can be generated to remove ammonia nitrogen from the wastewater.

5. Chemical oxidation method. A method of removing ammonia nitrogen by directly oxidizing it into nitrogen gas using a strong oxidant. Breakpoint chlorination is to use ammonia in water to react with chlorine to generate ammonia gas for deammonification. This method can also play a bactericidal role, but the residual chlorine produced will affect fish, so residual chlorine removal facilities must be attached.

Based on many years of research results on wastewater deammonification technology and practical experience in project implementation, Hongchang Liquid Ammonia Factory combines the research results of energy-saving and consumption-reducing technologies and equipment developed, and takes chemical wastewater treatment technology of power plants with high efficiency and good technical maturity as the basis. In view of the problems of easy consumption and passivation of electricity, high power consumption, and inability of wastewater treatment to meet standards in traditional electrochemical technology, innovative process flow design, high deammonification technology and equipment, energy-saving and consumption-reducing technology and equipment are adopted. Through research and development, Hongchang Liquid Ammonia Factory has developed high ammonia nitrogen wastewater treatment technology and solutions, subverting tradition, and using electrochemical high and low concentration wastewater treatment technology without water separation, chemicals, biochemicals, acid and alkali, flocculation, precipitation, or filter press.