The presence of ammonia nitrogen in water, the process of ammonia nitrogen removal by aeration and t

Presence form of ammonia nitrogen in water.

A1 Nitrogen-containing organic matter mainly comes from the decomposition of animal excreta and animal and plant corpses, and the decomposition first forms amino acids, and then gradually stabilizes according to the procedures of ammonia nitrogen, nitrite nitrogen and nitrate nitrogen. Therefore, when ammonia nitrogen is present in a water body, it means that the water body has been polluted for a short time.

Aeration to remove ammonia nitrogen process.

Taking ammonia nitrogen as an example, the higher the temperature, the more difficult it is for ammonia nitrogen to dissolve in water, the following table shows the partial pressure of ammonia nitrogen in the air at different temperatures at the same dissolved concentration (x), it can be seen that the higher the temperature, the higher the partial pressure of ammonia nitrogen, indicating the solubility of ammonia nitrogen.

Smaller. Partial pressure and dissolved concentration of ammonia at different temperatures.

In addition to the effect of partial pressure of air on the solubility of ammonia, ammonia dissolves in water to form ammonium ions.

NH4+), whose equilibrium reaction formula is:

NH3 + H2O NH4++ OH- equilibrium constant.

KB=From the above equation, it can be seen that when the pH is biased towards alkaline, the ammonium ions in the water will be converted into ammonia molecules, and when the pH is biased towards alkaline, the ammonia in the water will mostly exist in the form of ammonium ions. Ammonia molecules volatilize in water, so it is necessary to convert ammonium ions in water into ammonia molecules for air stripping.

Effect of aeration on ammonia nitrogen removal.

What is the choice of exhaust gas treatment process?

Feel free to ask.

Most of the ammonia nitrogen in water exists in the form of ammonium ions, and aeration to remove ammonia nitrogen requires alkali to make ammonium ions become ammonia monohydrate and then aeration to remove. The main impact on aeration is that the intensity of aeration should be sufficient, so as to support the ammonia.

Organic pollution and incomplete water ecosystems do not have the ability to self-purify.

Organic, inorganic, and aeration can turn ammonia nitrogen into nitro nitrogen.

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.

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 it completely eliminates nitrogen pollution in the water, and there is no secondary pollution. However, the disadvantage is that the cultivation of microorganisms and the control of process conditions. Upgrading the existing process, increasing the load of the process, carrying out project transformation on the basis of the original biochemical process, adding HNF-MP process, strong impact resistance, high concentration of bacteria can resist impact, self-rotating packing + multi-stage reflux separator, on the basis of not changing the original pool body, the ammonia nitrogen removal efficiency of the pool body is increased by 1-2 times.

Biological denitrification method uses microbial nitrification and denitrification to remove ammonia nitrogen in wastewater, and converts ammonia nitrogen in water into nitrogen to achieve the purpose of denitrification. Ammonia nitrogen is first converted to nitrite and nitrate by nitrifying bacteria and nitrosifying bacteria, and then denitrification is carried out to convert nitrate to nitrogen.

Among them, the HNF-MP process is currently a denitrification equipment with a relatively high land occupation for renovation projects and new projects. The use of high-efficiency nitrifying bacteria + self-rotating packing + multi-stage self-reflux separator strengthened the number of microorganisms in the reactor while inoculating nitrifying bacteria with good stress resistance, and increased the original concentration from 2000-3000mg L to 5000-10000mg L, which could greatly improve the reaction efficiency.

1) First of all, according to the sewage situation, use physical, chemical and biological methods. Among them, according to the actual situation, the breakpoint chlorination method, chemical precipitation method, blowing method and air stripping method, ion exchange method, short-range nitrification and denitrification method, AO process, liquid film method and other methods can be selected.

2) Some wastewater components are complex and have high concentrations, and it is difficult to meet the discharge standards by using a single treatment method, and several methods need to be combined to make the wastewater treatment meet the standards.

3) If the treatment of ammonia nitrogen sewage according to the above methods still does not meet the discharge requirements, it is necessary to choose the relevant water treatment agent treatment, and you can choose ammonia nitrogen treatment agent treatment. The main characteristics of ammonia nitrogen treatment agent are as follows:

Ammonia nitrogen agent is widely used in electroplating wastewater, papermaking wastewater, printing and dyeing wastewater, textile wastewater, slaughtering wastewater, circuit board wastewater, electrical wastewater, etc. The main reason why ammonia nitrogen treatment agent is suitable for post-treatment of ammonia nitrogen wastewater is that it is convenient to add and use, and the reaction process is relatively fast, and the reaction can be completed in a few minutes.

You can buy some ammonia nitrogen removers, such as ammonia nitrogen remover J-201. First of all, you first take a certain amount of ammonia nitrogen excess wastewater, roughly estimate the content of ammonia nitrogen, and then add industrial-grade sodium hydroxide to adjust the pH value of the water to alkaline, and then add an appropriate amount of ammonia nitrogen remover, stir evenly, let it fully react for 6 minutes, and then measure the content of ammonia nitrogen in the supernatant, which can generally be less than 5ppm.

Sewage nitrogen and phosphorus removal biological treatment TP is removed by excessive cell absorption;

Nitrogen removal is not due to excessive cellular uptake. The main mechanism is as follows:

Granular non-biodegradable organic nitrogen becomes an activated sludge component through bioflocculation and is removed from the system by removing the remaining activated sludge; Granular biodegradable organic nitrogen is converted to dissolved biodegradable organic nitrogen by hydrolysis. The dissolved non-biodegradable organic nitrogen is discharged with the treated effluent to determine the organic nitrogen concentration of the effluent; Dissolved biodegradable organic nitrogen is converted to ammonia nitrogen by ammoniation by heterotrophic bacteria, in which urea is rapidly hydrolyzed to ammonium carbonate. Under aerobic conditions, nitrifying bacteria oxidize ammonia nitrogen to nitrate nitrogen, and under anoxic conditions, denitrifying bacteria dissociate nitrate and reduce nitrate to gaseous nitrogen, which is removed from water.

Since denitrification in the anoxic zone requires a large amount of carbon source, the anoxic zone is generally placed at the front end of biological treatment (inlet end), but the influent water is mostly ammonia nitrogen and less nitrate nitrogen, which cannot be nitrified, so internal reflux is required. The total nitrogen concentration in the effluent of the inversion tank is the same as the internal reflux, so even in the theoretical state, the maximum nitrogen removal rate can only reach (r+r) (1+r+r), where r is the internal reflux ratio and r is the sludge reflux ratio.

According to your introduction, it should be pre-denitrification, and the effluent of the aerobic tank and the sludge of the secondary sedimentation tank need to be reflowed. You say that if the return flow rate is doubled, it is not appropriate to ensure the anaerobic environment of the anoxic pool in front, and the anoxic zone is not equal to anaerobic, and the do is less than that. It is also reasonable for your master to say that the dissolved oxygen in the aerobic pool should be controlled at about 1mg l, so as to prevent the anoxic area from being greater than that.

If the aerobic zone do is about 1, when the effluent return flow is doubled, the anoxic zone do is still greater than the time, the dissolved oxygen in the aerobic zone can not be reduced, and the effluent return flow can not be reduced at will (the nitrate nitrogen entering the anoxic zone will be less), at this time, the sludge output of the secondary sedimentation tank can be reduced without affecting the mud water separation effect of the secondary sedimentation tank, and the sludge layer in the tank will be raised, so that the sludge residence time in the secondary sedimentation tank will be increased, so that it will be in a defective oxygen or anaerobic state, which is also conducive to avoiding the rise of the anoxic zone do. The reduction of the sludge output of the secondary sedimentation tank will not affect the amount of sludge returning to the reaction tank, because the sludge is thickened in the mud layer for a long time when the mud layer in the secondary sedimentation tank is raised, and the sludge output is reduced but the concentration of the sludge is increased. If it is a contact oxidation process, the effluent will be reflowed, and the sludge will not be reflowed.

I'm not in favor of using pre-denitrification. Because of the high energy consumption of effluent reflux and the large reflux flow, the volume of the reaction tank is also large. It's not a good idea to get rid of nitrifying bacteria, but you know what you mean.

The main pollutant in sewage is ammonia nitrogen compounds, and sewage discharge standards strictly require the control of ammonia nitrogen compounds.

There are several common ways to remove ammonia nitrogen compounds from sewage:

1. Constructed wetland method, the artificially created wetland is composed of laying a sand layer, cultivating sludge and aquatic plants on the base stones, constituting a complete artificial imitation natural biological circulation system. After the sewage enters the constructed wetland, it is filtered by the sand and gravel layer, and the ammonia nitrogen compounds in the sewage are digested and absorbed by the biological fungi in the sludge, and the oxidation and absorption of aquatic plants. It can effectively reduce the ammonia nitrogen compounds in sewage.

Constructed wetlands require a relatively large volume.

2. Pool biofilm method, the current more mature process includes a o method, a a o method. In the tank of the artificial structure, a large amount of biofilm is attached to the hanging filler, and fungi that can absorb ammonia nitrogen compounds are cultivated, and the sewage flows through the biofilm. Fungi and ammonia nitrogen compounds undergo complex digestion and oxidation reactions, which effectively absorb ammonia nitrogen compounds.

According to the impurity content and nature of the sewage, different biochemical processes are adopted to coordinate and adjust the sewage treatment work accordingly.

3. Chemical agent treatment method, which is the use of compound agents with ammonia nitrogen elimination function, put into the sewage pool, and apply the ability of chemical reaction to eliminate ammonia nitrogen compounds in sewage.

To sum up, according to the needs and the actual production situation, the corresponding process method can be selected to remove the ammonia nitrogen compounds in the sewage, and a variety of methods can be used to work together when necessary to prevent the problem of excessive ammonia nitrogen in the treated effluent.

a a o process.

The diagram above shows the basic flow of the aa o process. It is one of the more commonly used methods.

I hope it can help you, welcome to follow, like, .

It can be comprehensively analyzed and considered whether it is due to the following reasons.

1. The water temperature is too low - the solution.

a. If there is a homogeneous adjustment pool, it can be heated in the pool, so that the fluctuation is relatively small;

b. If it is a direct water inlet, you can use electric heating or steam heat exchange or mixing to increase the water temperature, which requires more accurate temperature control to control the fluctuation of the water inlet temperature.

2. Increase the amount of water - the solution.

a. Increase equipment processing in the system to increase the designed processing capacity;

b. Reduce the amount of water inflow, but in actual operation, it can only be implemented for a few hours due to the residence time of the regulating tank and the risk of overflow of the external pipe network.

3. Increased concentration - solution.

a. If the "influent" ammonia nitrogen is high, it may be related to the influent water**, which can be tried to solve by limiting the influent concentration or limiting the effluent concentration of the production line.

You can also choose to upgrade the HNF-MP process directly, which can greatly improve the nitrification reaction efficiency. The nitrification load can be increased to; Compared with traditional technology, it can save 30%-50% of the floor space.

Heat it to 35 to 55 degrees Celsius, and be sure to put this heated water in a sealed plastic bag.

Ammonia nitrogen refers to the nitrogen present in water in the form of free ammonia (NH3) and ammonium ions (NH4+). The nitrogen content of animal organic matter is generally higher than that of plant organic matter.

At the same time, the nitrogen-containing organic matter in human and animal manure is very unstable and easily decomposes into ammonia. Therefore, when the ammonia nitrogen content in water is high, it refers to the chemical nitrogen in the form of ammonia or ammonium ions.

Ammonia nitrogen is a nutrient in water bodies, which can lead to water eutrophication, and is the main oxygen-consuming pollutant in water bodies, which is toxic to fish and some aquatic organisms.