What method should be used to better remove ammonia nitrogen exceeding the standard?

Ammonia nitrogen treatment methods are often divided into two categories: chemical treatment and biological treatment.

Biological treatment is what we often call biological denitrification, which mainly includes ammonia, nitrification, denitrification and finally nitrogen is removed from water. Biological denitrification is now a well-established process, such as the HNF-MP high-efficiency nitrification process, which is very common in water treatment.

Chemical treatment includes: Blowing off method, using the equilibrium relationship of ammonia nitrogen in water, adjusting pH to alkalinity, so that ammonia nitrogen exists in a non-ionic state NH3-N, and finally uses air to blow it out.

The breakpoint chlorination method uses ammonia nitrogen and chlorine to react to finally produce nitrogen to be removed from water. The amount of chlorine is added according to the chlorination curve.

For the ion exchange method, cation exchange resins are generally used.

There are various reasons for the excessive ammonia nitrogen in wastewater, such as the absence of nitrifying bacteria in the main biochemical system, insufficient residence time, insufficient alkalinity, insufficient aeration capacity, and operation errors. The HNF-MP high-efficiency nitrification process uses high-efficiency nitrification strains to inoculate the strains with good stress resistance and strengthen the number of microorganisms in the reactor, which greatly improves the reaction rate.

Method 1: Chemical treatment:

1. Blowing method: use the equilibrium relationship of ammonia nitrogen in water to adjust pH to alkalinity, so that ammonia nitrogen exists in a non-ionic state, and uses air to blow it out;

2. Breakpoint chlorination method: ammonia nitrogen and chlorine reaction are used to finally generate nitrogen to be removed from water, and the amount of chlorine is added according to the chlorination curve;

3. Ion exchange method: cation exchange resin is generally selected;

Method 2: Biological treatment method: through ammonia, nitrification, denitrification, and finally nitrogen is removed from the water.

The treatment method for ammonia nitrogen exceeding the standard is as follows:1. Blow-off method.

The blowing method is to separate the gas-liquid equilibrium relationship between the gas phase concentration and the liquid phase concentration of ammonia nitrogen under alkaline conditions, and the blowing efficiency is related to temperature, pH, and gas-liquid ratio.

2. Zeolite denitrification method.

The zeolite denitrification method is the exchange of cations in zeolite with NH4 in wastewater, and zeolite is usually applied when treating wastewater containing low concentrations of ammonia or wastewater containing trace amounts of heavy metals.

3. Membrane separation technology.

Membrane separation technology is the use of membrane selective permeability to achieve the effect of ammonia nitrogen removal, this operation method is simple and convenient, the highest rate of ammonia nitrogen is high, and there is no secondary pollution.

4. MAP precipitation method.

The MAP precipitation method involves the injection of phosphate and magnesium salts into wastewater with high concentrations of ammonia nitrogen.

5. Chemical oxidation.

Chemical oxidation is the direct oxidation of ammonia nitrogen into nitrogen gas using a strong oxidizing agent.

In the process of biological denitrification treatment of sewage, firstly, under aerobic conditions, the ammonia nitrogen in the sewage is oxidized to nitrite or nitrate through the action of aerobic nitrifying bacteria; Then, under anoxic conditions, denitrifying bacteria (denitrifying bacteria) are used to reduce nitrite and nitrate to nitrogen and escape from the effluent. Therefore, the biological denitrification of wastewater consists of two stages: nitrification and denitrification.

.Direct overall treatment 》Process construction can be directly considered, but the overall processing time and cost will be relatively high.

2.Add ammonia nitrogen remover Ammonia nitrogen, total nitrogen Test the concentration of total nitrogen and ammonia nitrogen first, if the concentration difference is not large, you can directly treat it with ammonia nitrogen remover, the dosing is simple, 5-6 minutes fast.

I think the first step in denitrification --- nitrification, that is, the conversion of ammonia nitrogen into nitrate and nitrite, which is not controlled!

Exceeding the total ammonia nitrogen standard can be removed by biological nitrogen removal method, ammonia blowing method, ion exchange method or breakpoint chlorination method, so as to achieve the purpose of reducing the ammonia nitrogen index in sewage.

If the higher the ammonia nitrogen and the higher the total nitrogen of soy sauce, the better, and there is no need to control, these two indicators are to test the quality of soy sauce, and the higher the most fundamental index, the better the product quality.

Nitrate nitrogen (NO3) is the main body in natural surface water and groundwater, and the ammonia nitrogen in the form of free ammonia (NH3) and ammonium ions (NH4+) in the form of nitrogen in polluted water bodies is called hydrated ammonia, also known as non-ionic ammonia. Non-ionic ammonia is the main factor causing poisoning of aquatic organisms, while ammonium ions are relatively non-toxic. National standard class surface water, non-ionic ammonia nitrogen concentration 1 mg liter.

Ammonia nitrogen is a nutrient in the water body, which can lead to the phenomenon of water eutrophication, is the main oxygen depleting pollutant in the water body, and is toxic to fish and some aquatic organisms.

1. The impact of excessive ammonia nitrogen content in water on human health.

Ammonia nitrogen in water can be converted into nitrite under certain conditions, and if drunk for a long time, the nitrite in the water will combine with protein to form nitrosamines, which is a strong carcinogen and extremely bad for human health.

2. The impact of ammonia nitrogen in sewage on the ecological environment.

Ammonia nitrogen is mainly free ammonia, which is dozens of times more toxic than ammonium salt, and increases with the enhancement of alkalinity. Ammonia nitrogen toxicity is closely related to the pH value and water temperature of the pool water, in general, the higher the pH value and water temperature, the stronger the toxicity, and the harm to fish is similar to nitrite.

The oxidation process will cause the concentration of dissolved oxygen in the water body to decrease, resulting in the black and smelly water body, and the water quality will decline, which will affect the survival of aquatic animals and plants. When the concentration of ammonia nitrogen in the water body is high, it will lead to eutrophication of the water body, and then cause a series of serious consequences. When the molecular ammonia concentration in the water body is too high, it will cause toxemia in fish and shrimp, and long-term high ammonia nitrogen will affect the growth and reproduction of fish and shrimp, and the severity will be poisoning to death.

The harm of ammonia nitrogen to aquatic organisms is acute and chronic. Chronic ammonia nitrogen poisoning is associated with reduced food intake, slowed growth, tissue damage, and reduced oxygen transport between tissues.

Fish are sensitive to ammonia nitrogen in water, and high levels of ammonia nitrogen can lead to fish death. The hazards of acute ammonia nitrogen poisoning are: hyperactivity, loss of balance in the water, convulsions, and even death in severe cases.

1. Blow-off method.

When the content of ammonia nitrogen is too high, it can be treated by blowing, which belongs to a method of separation under alkaline conditions, using the gas-liquid equilibrium relationship between the gas-phase concentration and the liquid phase concentration of ammonia nitrogen, and the blow-off efficiency is related to temperature, pH and gas-liquid ratio.

2. Zeolite denitrification.

When the ammonia nitrogen content is too high, it can also be treated by zeolite denitrification, and the cations in the zeolite are exchanged with NH4+ in the wastewater to achieve the purpose of denitrification, and zeolite is often used to treat low-concentration ammonia-containing wastewater or wastewater containing trace heavy metals.

3. Chemical oxidation.

Chemical oxidation is a method of direct oxidation of ammonia nitrogen into nitrogen by strong oxidant, so as to remove it, and the breakpoint chlorination is the reaction between ammonia and chlorine in water, and then the form of nitrogen deamination is generated, which can also have the effect of sterilization.

4. Ion exchange.

Ion exchange is the use of exchangeable ions in insoluble ionic compounds to exchange with other isotropic ions in the solution, so as to firmly adsorb NH4+ in wastewater on the surface of the exchanger, and finally achieve the purpose of removing ammonia nitrogen.

Hello, glad to answer for you :

The hazards of high ammonia nitrogen wastewater are mainly as follows:

On the one hand, ammonia nitrogen in wastewater is an important substance for water eutrophication and environmental pollution, which is easy to cause the proliferation of algae and other microorganisms in the water, and the operation of tap water treatment plants is difficult, resulting in the odor of drinking water, and in serious cases, the dissolved oxygen in the water will decrease, a large number of fish will die, and even lead to the drying up and extinction of the lake.

On the other hand, ammonia nitrogen will also increase the amount of chlorine used in the process of feed water disinfection and industrial circulating water sterilization. corrosive to some metals (copper); When sewage is reused, ammonia nitrogen in reclaimed water can promote the reproduction of microorganisms in water pipelines and water equipment, form bioscale, block pipes and water equipment, and affect heat exchange efficiency.

Secondly, ammonia is oxidized to nitrite and nitrate under the action of nitrifying bacteria, nitrate is induced by drinking water and methemoglobinosis in infants, and nitrosamines produced after nitrite hydrolysis have strong carcinogenicity and directly threaten human health.

For industrial wastewater with high ammonia nitrogen concentration, the commonly used treatment methods include blowing method and chemical precipitation method, and chemical agents can also be added to remove ammonia nitrogen molecules from the wastewater.

1) Due to the oxidation of NH4+-N, the concentration of dissolved oxygen in the water will decrease, resulting in the black and smelly water body and the water quality will decline, thus affecting the survival of aquatic animals and plants.

2) High nitrogen content in wastewater can lead to eutrophication of water bodies, which can lead to a series of serious consequences. Due to the presence of nitrogen, the number of photosynthetic microorganisms (mostly algae) increases, i.e. eutrophication occurs in the water body. Endanger fish, aquatic life and other life.

What should I do if the ammonia nitrogen exceeds the standard? What can be done?

Biological denitrification is one of the commonly used denitrification methods, suitable for the treatment of low-concentration ammonia nitrogen wastewater, and the treatment effect is stable and reliable, the biggest advantage of biological denitrification is that the nitrogen pollution in the water is completely eliminated, and there is no secondary pollution. The integrated HNF process and IDN-BMP enrichment and integration equipment ensure stable operation of the system and realize all-round wastewater denitrification.

1.Ion exchange method.

The different affinities or selectivity of ion exchange resins for various ions are the basic conditions for ion exchange. At present, zeolite natural ion exchange substances are mainly used as ion exchange substances in sewage treatment, but this method of removing ammonia nitrogen in sewage has not been applied in China.

2.Air blowing method.

Ammonia blowing includes three processes: one is to increase the pH value of sewage and convert NH4+ into NH3 in sewage; the second is the repeated formation of water droplets in the blow-off tower; The third is to circulate a large amount of air through the blowing tower to increase the contact between gas and water and stir the water droplets.

The main problem of this process scheme for removing ammonia nitrogen in sewage is that the pH value of sewage needs to be adjusted, a large amount of lime is added, and the amount of chemical dosage is large, and a large amount of sludge is also generated, which increases the difficulty of treatment and sludge treatment capacity: because a large amount of circulating air is required, the power cost is higher; There is no precedent for this method to be used in urban sewage treatment, and there is also a lack of operation and management experience, so it is not recommended.

3.Zhanqing HNF-MP, biological denitrification process.

Biological denitrification will undergo a certain chemical reaction of ammonia nitrogen in sewage under the action of oxygen, and then realize the decomposition of ions and organic compounds, and finally produce gas to be discharged to achieve the effect of sewage purification. For renovation projects and new projects, the number of microorganisms in the reactor was strengthened by using high-efficiency nitrifying bacteria + self-rotating packing + multi-stage self-reflux separator, which greatly improved the reaction rate.

The biological method can be used, and the biological nitrification denitrification and denitrification treatment process includes two stages: nitrification and denitrification. The nitrification process refers to the oxidation of ammonia nitrogen to nitrate nitrogen and nitrite nitrogen under the action of nitrate and nitrite bacteria under aerobic conditions; Then, through anoxic conditions, denitrifying bacteria reduce nitrate nitrogen and nitrite nitrogen into nitrogen, so as to achieve the purpose of denitrification. The process is complete, the processing capacity is large, it can effectively remove the solubility and colloidal state of biodegradable organic compounds, etc., with good stability, low risk and low investment in the later stage.

01 Vertex chlorination.

This method is a chemical denitrification process in which chlorine or sodium hypochlorine acenate is introduced into wastewater to oxidize NH3-N to N2. The amount of chlorine required in the treatment of ammonia wastewater depends on the temperature, pH and concentration of ammonia nitrogen.

Oxidation of ammonia nitrogen requires 9 10 mg of chlorine, pH 6 7 is the optimal reaction range, and the exposure time is hours.

Features: The chlorination method has a high treatment rate, stable effect, and is not affected by temperature.

02MAP precipitation method.

The addition of phosphorus salts and magnesium salts to the ammonia nitrogen wastewater makes the pollutants in the wastewater form precipitates or polymers with little solubility, so as to achieve the effect of removing ammonia nitrogen.

Features: Ammonia nitrogen in wastewater can be used as fertilizer, if the phosphate in the wastewater is high, only need to add magnesium salt, a small amount of phosphate salt or not, you can achieve nitrogen and phosphorus removal, but the proportion between the three needs to be properly controlled.

03 Chemical Agent Law.

Add chemical agent-ammonia nitrogen remover, and the active ingredient in the agent reacts with ammonia nitrogen to become harmless gas volatilization to achieve the effect of removing ammonia nitrogen.

Features: 5 minutes, the removal rate can reach more than 96%, no secondary pollution, simple and convenient to use, and the wastewater after the reaction can be directly discharged (at present, most enterprises are using this method, and the manuscript branch is used to make up for the shortcomings of the biochemical process).

Ammonia nitrogen in water refers to ammonia compounds in the form of ammonia (NH3) or ammonium (NH4) ions. Ammonia nitrogen is one of the most harmful forms of various types of nitrogen, and it is a sign of water pollution, and its harm to the water ecological environment is manifested in many aspects. Like COD, ammonia nitrogen is also the main oxygen consumption pollution code in the water body, and the oxidative decomposition of ammonia nitrogen causes the dissolution in the water to be consumed by Acacia acacia.

Ion exchange method The different affinity or selectivity of ion exchange resins for various ions is the basic condition of ion exchange.