Removal method of total nitrogen and ammonia nitrogen

The nitrogen entering the water body is mainlyInorganic nitrogen和Organic nitrogen之分。

Inorganic nitrogen includes ammonia nitrogen (referred to as ammonia nitrogen) and nitrate nitrogen。Ammonia nitrogen includes free ammonia nitrogenNH₃-NAnd ammonium nitrogenNH₄⁺-N;Nitrate nitrogen includes nitrate nitrogenNO₃^--NAnd nitrite nitrogenNO₂^--N。

Organic nitrogen mainly includes urea, amino acid, protein, nucleic acid, uric acid, fatty amine, organic base, amino sugar and other nitrogen-containing organic matter。Soluble organic nitrogen is mainly in the form of urea and protein,It can be converted to ammonia nitrogen by actions such as ammoniation。

1.1总氮

Determination method of total nitrogen:一是Organic nitrogen and inorganic nitrogen compounds (ammonia nitrogen, nitrite nitrogen, nitrate nitrogen) were determined and then added together。二是After oxidizing with potassium persulfate to convert organic nitrogen and inorganic nitrogen into nitrate, the nitrate ion in the solution is measured by ion selective electrode method, and can also be determined by ultraviolet method or reduction to nitrite, azo colorimetry, and ion chromatography。

1.2 氨氮

Two approximate sensitivity colorimetric methods commonly used to determine ammonia are the classical Nessler reagent method and the phenol-hypochlorite method.Titration and electrode methods are also commonly used to determine ammonia;When the ammonia nitrogen content is high, the distillation titration method can also be used。(National standards include Nath's reagent method, salicylic acid spectrophotometry, distillation - titration method)

2.1 Use nitrogen removal process

2.1.1The traditional process of denitrification by activated sludge

Under the action of various microorganisms, the traditional biological method converts ammonia nitrogen in wastewater into nitrogen through a series of reactions such as nitrification and denitrification, so as to achieve the purpose of wastewater treatment。Such processes includeBarth proposed three stage activated sludge method, two stage activated sludge method and other processes。

2.1.2 Anoxic-aerobic activated sludge denitrification system (A/O method)

The anoxic-aerobic activated sludge denitrification system (A/O method) was developed in the early 1980s and has been widely used at present。Compared with the two-stage activated sludge process, this process sets the anoxic denitrification reactor in front of the aerobic reactor, so it is often called "preemptive denitrification biological nitrogen removal system".The processing process is shown in the figure below。

2.1.3Other biological nitrogen removal processes

(1) Oxidation ditch process

(2) Biological turntable biological nitrogen removal process

Control the operating conditions of each stage of biological turntable，Put them in an aerobic state and anoxic state respectively，That is, aerobic biological turntable and anaerobic biological turntable need to be used respectively in the whole process，BOD removal and nitration of ammonia nitrogen were achieved in different aerobic biological turntables，In the anaerobic biological turntable, denitrification is mainly realized，The principle is similar to the above-mentioned three-stage activated sludge biological denitrification process，Only in this process to achieve all levels of function is to rely on the biological turntable to complete。

2.2 Utilization OrganismsStrain treatment

The use of some biological strains can also play a certain role in the degradation of total nitrogen and ammonia nitrogen, but the daily maintenance needs are relatively large.Generally, it is necessary to arrange long-term technical personnel to operate on site。

2.3 Treatment with chemical agents - ammonia nitrogen remover

First test the concentration of total nitrogen and ammonia nitrogen, if the concentration difference is not large, ammonia nitrogen removal agent can be directly used in the case of ammonia nitrogen concentration below 200mg/L, and the dosage is determined according to the water quantity on site.So when you get rid of the ammonia, the total nitrogen will go down。