Hazard of ammonia nitrogen, nitrate nitrogen and nitrite nitrogen

Sources of ammonia nitrogen, nitrate nitrogen, and nitrite nitrogen

(1) Decomposition products of nitrogen-containing organic matter in domestic sewage by microorganisms, and drainage of farmland. Nitrogen-containing organic compounds such as food residues in urban domestic sewage produce ammonia nitrogen under the decomposition of microorganisms, and ammonia nitrogen is also produced during the growth of crops and the use of nitrogen fertilizer, and discharged into the city's sewage treatment plant or discharged directly. In the water.

(2) Ammonia and nitrite can mutually convert ammonia in water to form nitrite under the action of oxygen, and further form nitrate. At the same time, the nitrite in the water can also be converted into ammonia by the action of microorganisms under anaerobic conditions.

(3) Certain industrial wastewater, such as coking wastewater and synthetic ammonia fertilizer plant wastewater. Chemical plants such as fertilizer plants, power plants, and cement plants discharge ammonia-containing gases, dust, and smog into the environment. With the continuous improvement of people's living standards, private cars are also increasing, and a large number of self-use cars and various models. Vehicles such as trucks also emit a certain amount of ammonia-containing vehicle exhaust to the ambient air. The ammonia in these gases dissolves in water, forming ammonia nitrogen, which contaminates the water.

Impact on human health

The ammonia nitrogen in the water can be converted into nitrite under certain conditions. If it is used for a long time, the nitrite in the water will combine with the protein to form nitrosamine, which is a strong carcinogen and is extremely detrimental to human health.

Impact on the ecological environment

The main harmful effect of ammonia nitrogen on aquatic organisms is free ammonia, which is several times more toxic than ammonium salt and increases with the increase of alkalinity. The toxicity of ammonia nitrogen is closely related to the pH value of the pool water and the water temperature. Generally, the higher the pH value and water temperature, the stronger the toxicity, and the harm to fish is similar to that of nitrite. The damage of ammonia nitrogen to aquatic organisms is acute and chronic. Chronic ammonia nitrogen poisoning hazards are: reduced feeding, slower growth, tissue damage, and reduced oxygen transport between tissues. Fish are sensitive to ammonia nitrogen in water, which can cause fish to die when the ammonia nitrogen content is high. The acute ammonia nitrogen poisoning hazard is: aquatic organisms are characterized by hyperactivity, loss of balance in water, convulsions, and even death.

Relevant environmental standards and the need for environmental protection work

Ammonia nitrogen causes pollution to water bodies, killing fish, or forming nitrites that endanger human health. Determination of ammonia nitrogen in water helps to assess the contamination and "self-cleaning" of water bodies. Therefore, the revision of this standard is also to adapt to and meet the environmental quality standards and pollutant discharge (control) standards of pollution.

The monitoring requirements of the project and the monitoring requirements of the pollutants involved in the key environmental protection work.