What is the reason for the high total nitrogen content of urban sewage influent

The high total nitrogen content of urban sewage inlet water is due to the increase of domestic sewage. For example:

Vegetable sewage, bathing sewage, laundry sewage-laundry detergent, soap (containing a lot of phosphorus and nitrogen), etc.

Total nitrogen is defined as the total amount of inorganic and organic nitrogen in various forms in water. These include inorganic nitrogen such as NO3, NO2 and NH4 and organic nitrogen such as proteins, amino acids and organic amines, calculated in milligrams of nitrogen per liter of water. It is often used to indicate the degree to which a body of water is contaminated with nutrients.

The total nitrogen content in water is one of the important indicators to measure water quality. Its measurement is useful to evaluate the pollution and self-purification status of water bodies. When the nitrogen and phosphorus substances in the surface water exceed the standard, microorganisms multiply in large quantities, plankton grow vigorously, and eutrophication appears.

Domestic sewage, of course, is high!

Vegetable washing - pesticides (pesticides in the field are adsorbed by the soil).

Bathing - dander.

Brush the pot - food scraps.

Laundry - laundry detergent soap (contains a lot of phosphorus and nitrogen).

Rainwater - motor vehicle pavement absorbs a large amount of exhaust gas.

Wait, wait, there are too many, everything contains carbon and nitrogen! Our bodies are made up of carbon and nitrogen!!

1 Inflow of farmland water with chemical fertilizers.

2 Laundry detergent.

3 Nox acid precipitation formation.

The main meaning of the total nitrogen content of sewage is that the total nitrogen content of the sewage as a whole is relatively high, which exceeds the scope and requirements of the standard, so at this time, it must be treated reasonably by professional technology and methods to achieve a more environmentally friendly degree.

When the influent water is exceeded, the COD, total nitrogen, total phosphorus and SS of the raw water may inexplicably increase, and the SS and total phosphorus can be removed by coagulation and precipitation. COD excess is based on the excessive content of these organic matter, the dissolved substances or colloidal substances in the wastewater can be removed by physical and chemical actions, and the biological treatment method can also be used to convert the organic pollutants and inorganic microbial nutrients in the wastewater into stable and harmless substances through microbial metabolism.

3. Solutions for exceeding the total nitrogen standard in sewage:

1.Ammonia nitrogen removal The use of microbial nitrification and denitrification to remove ammonia nitrogen in wastewater is based on the principle of converting ammonia nitrogen into nitrogen through the combined action of the bio-promoting nitrifying bacterium MicroBoost-N and the bio-promoting total nitrogen removal bacterium MicroBoost-DEN, so as to achieve the purpose of denitrification. First of all.

2.Removal of organic nitrogen Biological method, nitrogen compounds can be converted to nitrogen under biological action: Chemical method, nitrogen compounds are directly converted from organic nitrogen and ammonia nitrogen to nitrogen through oxidation:

3.Removal of nitrate nitrogen Nitrate nitrogen mainly refers to nitrate ions, and currently uses ion exchange, membrane permeation, adsorption and biological denitrification.

Well, there will also be a total nitrogen in the sewage, but this is also an indicator, through which it can be used to feedback the pollution of this sewage.

Total nitrogen includes ammonia nitrogen, organic nitrogen, nitrite nitrogen, nitrate nitrogen. There are two possible causes of high total nitrogen in sewage:

1.The effluent has high ammonia nitrogen, resulting in high total nitrogen.

Cause: There was a problem with the aerobic nitrification system, resulting in high ammonia nitrogen.

Solution: Control the support of dissolved oxygen, pH and other parameters to enhance the nitrification system.

2.The ammonia nitrogen in the effluent meets the standard, while the total nitrogen is high.

Reason: Incomplete denitrification reaction in anoxic pond, reflux ratio, sludge age, suspended solids and other factorsSolution: Add Zhanqing denitrification complex bacillus, carbon source, etc., or use IDN-BMP total nitrogen treatment enrichment integrated equipment.

1. The reasons for exceeding the standard may be:

1) Your company is more water-saving;

2) Your company is very densely staffed, with a large number of personnel, and the frequency of toilet use is high;

3) The time period of excretion of your company's personnel is relatively concentrated, such as during the day, and the sampling of sewage plants is also in this time period.

4) The discharge port is very close to the toilet (resulting in an unrepresentative sample taken by the sewage plant personnel).

5) Other sewage is mixed in.

2. Investigation method: regular sampling and testing;

1) Samples were taken at different time periods on the same day at the discharge port to determine the ammonia nitrogen value.

2) Sampling at different discharge wellheads in the plant area to determine the ammonia nitrogen value.

3) Measure the ammonia nitrogen value of the sample in the inspection well of the pipeline closest to the toilet.

Analyze them separately to determine whether your unit is caused by uneven discharge, whether it is unrepresentative sampling, and whether it is caused by toilet discharge.

If not, then there must be a high ammonia nitrogen value in the well somewhere, and the investigation of the wastewater there** can determine where the high ammonia nitrogen value wastewater comes from.

3. Treatment method: I don't know the reason, there is no specific improvement method. In short, the right medicine is enough.

4. Purchase tools and facilities: If your unit ammonia nitrogen value exceeds the standard a lot, and finally finds that there is no objective reason, that is, it exceeds the standard, then you need to set up treatment facilities.

There are four main reasons for the excessive ammonia nitrogen in sewage: the ammonia nitrogen concentration of raw water exceeds the process design value; The water volume is overloaded in a short period of time, and the residence time of the sewage reaction is insufficient; Temperature, nutrient ratio, pH value, etc. will affect the reproduction of strains, and the problem of ammonia nitrogen exceeding the standard in winter is serious. Equipment aging, facility maintenance and renewal, etc.

Questions. Should the anaerobic pool be oxygenated.

No, anaerobic is a biochemical treatment process in which anaerobic bacteria participate, anaerobic bacteria do not need oxygen, it can be said that oxygen is toxic to them, so the dissolved oxygen in the system is required to be equal to zero, which is the biggest feature, in addition, the anaerobic reaction requires a higher and more stable temperature, of which the medium temperature reaction is between 31 and 33 degrees Celsius. Anaerobic reactions require a strict pH.

Possible reasons why ammonia nitrogen analysis results are higher than total nitrogen during water quality testing.

There are several possible reasons why ammonia nitrogen analysis results are higher than total nitrogen during water quality testing

1. Error of sample introduction Because the nitrogen compounds in the water are constantly changing, the samples that are sent back to the laboratory for experimental analysis after collection, their storage time, storage location, light conditions, etc., and even the order of sampling by analysts, etc., will bring different errors to the experimental analysis of ammonia nitrogen and total nitrogen.

2. Errors introduced by the experimental environment There are toilets or ammonia storage around the laboratory, so that the air in the laboratory often contains ammonia and ammonium salts to varying degrees, and ammonia and ammonium salts are very soluble in water, so that the experimental water also contains ammonium ions to varying degrees. It can be said that it is difficult to achieve ammonia-free operation in the whole experimental analysis process, and this environment certainly brings errors that are difficult to completely deduct with the blanks of the whole program for the analysis of ammonia nitrogen and total nitrogen, especially for the positive error of the experimental test of ammonia nitrogen, which is more direct and larger.

3. Errors introduced by experimental conditions The analysis of ammonia nitrogen usually adopts the more classical Nessler's reagent photometry, although the color development requires an alkaline environment, but there is no long pretreatment process, and the results can be calculated after direct color development and determination. In general, there is no large error in the experimental conditions. The analysis of total nitrogen should undergo 30min of heating and pressurization treatment under alkaline conditions, so that all the different forms and states of nitrogen contained in the sample are converted into nitrate ions, and the pH value of the sample is adjusted with dilute hydrochloric acid, and then colorimetric determination is carried out on a UV spectrophotometer.

This is a very long pretreatment process compared to the determination of ammonia nitrogen, and the most important thing is the efficiency of the pretreatment, because it is difficult to achieve 100% efficiency of any pretreatment, that is, the conversion of nitrogen compounds in the sample after pretreatment cannot be 100%, and there must be errors.

4. Error of sample turbidity introduction The turbidity influence that can be eliminated by the pretreatment of total nitrogen analysis cannot be eliminated in the analysis of ammonia nitrogen, and different kinds of cuvettes are commonly used in colorimetry, and these influencing factors add up to bring differences to the final results.

5. Errors introduced by different analystsTherefore, I think the key points should be as follows: (1) The analysis time of total nitrogen and ammonia nitrogen should be consistent; (2) The measurement of total nitrogen is to eliminate the interference of turbidity.

The ammonia nitrogen in the effluent of the wastewater treatment plant is too low, but the total nitrogen is high, which may be the reason.

The ammonia nitrogen in the effluent of the sewage treatment plant is too low, but the total nitrogen is very high, which may be the reason why the ammonia nitrogen in the effluent is low, but the total nitrogen is very high, because there may be two points: 1The dissolved oxygen concentration in the reaction pool is very high, and there is no denitrification stage, all ammonia nitrogen is oxygenated into nitrate nitrogen, and the total denitrification efficiency is not high. 2.

Although the reaction tank has a denitrification section, the carbon:nitrogen ratio of the incoming water is less than 5:1, the amount of nitrogen is high, and there is not enough carbon during denitrification, so the total nitrogen will also be very high.

The adjustment method of high total nitrogen in sewage plant is as follows:

1. Biological method: biological denitrification technology is completed through ammoniation, nitrification, denitrification and assimilation. The process of traditional biological nitrogen removal is mature, and the nitrogen removal effect is good. However, there are shortcomings such as long process flow, large land occupation, frequent need for additional carbon sources, high energy consumption and high cost.

When the ammonia nitrogen of domestic sewage exceeds the standard, the biological treatment method should be adjusted in time to increase the reaction time of nitrification and denitrification, so that the ammonia nitrogen can be degraded more quickly.

2. Chemical method: the oxidation of ammonia nitrogen remover is used to decompose ammonia nitrogen, and the ammonia nitrogen decomposition efficiency under this method is fast, the processing time is fast, and the agent is generally directly added to the water outlet for use, without too many cumbersome operations.

3. Breakpoint chlorination method: Breakpoint chlorination method is a chemical denitrification process in which excess chlorine or sodium hypochlorite is added to oxidize ammonia nitrogen in wastewater into nitrogen. The treatment efficiency of this method can reach 90%-100%, and the treatment effect is stable and not affected by water temperature.

However, the cost of transportation is high, and the by-products chloramine and chlorinated organic compounds will cause secondary pollution.

Reasons for the high total nitrogen in sewage plants:

1. There is a problem with the aerobic nitrification system.

2. The reflux ratio is not enough, resulting in insufficient dilution, resulting in an increase in ammonia nitrogen and a high total nitrogen in the anoxic pool.

3. Incomplete denitrification of anoxic pond (there are many reasons for this, such as: destruction of anoxic environment, insufficient carbon source, insufficient residence time, etc., specific situation is analyzed).

4. The biochemical treatment effect is poor, the effluent is dark in color, the turbidity is high, and there are many suspended solids. <>

The removal of total nitrogen includes the removal of ammonia nitrogen, the removal of organic nitrogen, the removal of nitrate nitrogen, etc.

1. Ammonia nitrogen removal.

Generally, it can be removed by the following methods.

1) Break point chlorine oxidation method, by adding sodium hypochlorite or bleaching powder for oxidation, ammonia nitrogen is converted into nitrogen gas for release, and the common ammonia nitrogen remover on the market is basically bleaching powder.

2) The use of microbial nitrification and denitrification to remove ammonia nitrogen in sewage (wastewater) is based on the combined action of nitrifying bacteria and denitrifying bacteria to convert ammonia nitrogen in water into nitrogen to achieve the purpose of denitrification.

2. Organic nitrogen removal.

The following methods are commonly used:

In the biological method, nitrogen compounds can be converted into nitrogen under biological action;

In the chemical method, nitrogen compounds are directly converted from organic nitrogen and ammonia nitrogen to nitrogen through oxidation.

The biological method has low cost and stable effect, but the process is complex, difficult to operate, and covers a large area and has a long running time. The chemical method eliminates the intermediate conversion step, which is faster and more direct, but the cost is high, the breakpoint chlorination method is difficult to control, and the effect is unstable.

3. How to remove excessive nitrate nitrogen?

Nitrate nitrogen mainly refers to nitrate ions, and there are currently methods of ion exchange, membrane permeation, adsorption and biological denitrification. Among them, the ion exchange method, membrane permeation method and adsorption method are only the concentration and transfer of nitrate ions, and cannot really remove the total nitrogen, and the concentrated nitrate waste liquid needs to be further treated.

In biological denitrification, it mainly refers to the process by which nitrate ions are converted into nitrogen gas by the degradation of denitrifying bacteria.

There are many ways to reduce ammonia nitrogen in sewage, among which the following blowing method, zeolite deamination method, and chemical oxidation method are the three most commonly used methods to reduce ammonia nitrogen in sewage.

How to reduce ammonia nitrogen in wastewater?

1. Blowing method: a method for separating the gas-liquid equilibrium relationship between the gas phase concentration and the liquid phase concentration of ammonia nitrogen under alkaline conditions. It is generally believed that the blow-off efficiency is related to temperature, pH, and gas-liquid ratio.

2. Zeolite deamination method: the cations in the zeolite are exchanged with NH4+ in the wastewater to achieve the purpose of denitrification. Zeolite is generally used to treat wastewater containing low concentrations of ammonia or wastewater containing trace amounts of heavy metals.

3. Chemical oxidation method: a method that uses a strong oxidant to directly oxidize ammonia nitrogen into nitrogen for removal. The ammonia nitrogen remover is directly added to the sewage, which can quickly decompose the ammonia nitrogen into nitrogen, and more than 96% of the ammonia nitrogen can be removed in 5 minutes.