Ammonia nitrogen content standard in water

Ammonia nitrogen is a nutrient in water, which can lead to eutrophication. It is the main oxygen-consuming pollutant in water and is poisonous to fish and some aquatic organisms. Ammonia nitrogen in water can be converted into nitrite under certain conditions. If it is consumed for a long time, it will be extremely harmful to human health. my country's current relevant environmental protection standards that involve ammonia nitrogen wastewater discharge indicators include 'Surface Water Environmental Quality Standards' (GB3838-2002), 'Groundwater Environmental Quality Standards' (GB/T14848-93), 'Sewage Comprehensive Discharge Standards' (GB8978- 1996), and related industry-type water pollutant discharge standards, the ammonia nitrogen standard limit ranges from 0.02mg/L to 150mg/L. Different water quality has different standards for ammonia nitrogen content. For example, the standard of 'Fishery Water Quality Standard' stipulates that the content of non-ionic ammonia nitrogen should not exceed 0.02 mg/L, because the main harmful effect of ammonia nitrogen on aquatic organisms is free ammonia, which is more toxic than ammonium salt. Dozens of times larger, and increases with the enhancement of alkalinity. The toxicity of ammonia nitrogen is closely related to the pH value of water quality and water temperature. In general, the higher the pH value and water temperature, the stronger the toxicity. The harm to fish is similar to that of nitrite. Why is the ammonia nitrogen exceeding the standard? There are mainly these reasons: 1. The discharge of domestic sewage and certain nitrogen-containing industrial wastewater; 2. The used plant fertilizers (ammonia water, urea, ammonium salt fertilizer, nitrate fertilizer, etc.) enter the ground water or Seep into groundwater through soil; 3. Animal excrement and decomposition products of animal and plant decay 'Technical Specifications for Surface Water and Sewage Monitoring' (HJ/T91-2002) lists ammonia nitrogen as rivers, lakes, reservoirs and centralized drinking water sources must-test items. Iron and steel industry, coking, chemical fertilizer (nitrogen fertilizer), synthetic ammonia industry, textile dyeing and finishing industry, food processing, slaughtering and meat processing, beverage manufacturing industry, aerospace propellant, shipbuilding industry, pipeline transportation industry, hotels, restaurants, amusement places and public Drainage units such as service industries and domestic sewage also list ammonia nitrogen as a must-test item. Therefore, the monitoring of ammonia nitrogen indicators is very important in environmental quality and pollution control.