Method for culturing denitrifying bacterium and determining water body nitrate nitrogen isotope composition

Abstract

The invention relates to the technical field of water body nitrate pollution treatment and control, and is a method for culturing a denitrifying bacterium and using the bacterium to determine water body nitrate nitrogen isotopic composition. The method comprises the following steps of: (1) carrying out enrichment culture of the denitrifying bacteria, (2) detecting whether the denitrifying bacteria completely converse NO3- in a culture fluid, (3) concentrating of the denitrifying bacteria, (4) adding the concentrated cell culture to a sample bottle, purifying an upper space and removing N2O in the denitrifying bacterium liquid, (5) conversing NO3- in the sample to N2O, (6) determining the N2O nitrogen isotope, and (7) correcting the nitrogen isotope determination result to complete the test. The positive effects of the invention are as follows: the culture of the denitrifying bacteria can be completed by using only a common saline bottle or a triangular flask, the detection of sulfanilamide color development improves the reliability of the determination result, and the determination cost is reduced. For the current situation that severe water body nitrate pollution is urgently needed to be treated, the method of the invention has the advantages of scientificalness, simplicity, and high maneuverability, and has a broad popularization prospect.

Description

technical field [0001] The invention relates to cultivating denitrifying bacteria and using the bacteria to distinguish the isotope composition of nitrate nitrogen, belonging to the technical field of nitrate pollution treatment and control of water body. Background technique [0002] Groundwater is an irreplaceable important resource necessary for my country's economic and social development and people's life. More than 1.5 billion people worldwide rely primarily on groundwater for drinking water. In some cities and vast rural areas in China, groundwater is often the only source of water supply. In recent years, the pollution of groundwater by nitrate nitrogen has become a common concern in the world. In many countries and regions in Europe and the United States, the content of nitrate nitrogen in groundwater has seriously exceeded the standard. Many areas in my country have also been polluted by nitrate nitrogen to varying degrees, especially in rural areas. The pollutio...

AI Technical Summary

Problems solved by technology

At present, the application of denitrifying bacteria to test nitrate nitrogen isotopes in China is still relatively small, and the existing literature methods also have the following disadvantages: (1) The cultivation of denitrifying bacteria requires special culture bottles, which are difficult to find in ordinary laboratories; (2) Whether the nitrate in the culture solution is completely converted to N after enrichment culture of denitrifying bacteria 2 O, without affecting follow-up sample determination, this index detection method is lacking at present; (3) N produced with sample 2 O gas cannot be analyzed directly, and N 2 O gas is injected into the sample bottle connected to the mass spectrometer at one time and then analyzed, which requires a large sample volume

Comprehensive analysis At present, there is no detailed and operable denitrifying bacteria method to test the nitrate nitrogen isotope in water, which limits the application of this method in the traceability and treatment of nitrate pollution in water