Ammonia pollution

Ammonia pollution refers to the pollution to the environment when ammonia is produced and used during human activities. The background concentration of ammonia in the atmosphere is less than 10×10^-6. The explosion limit is when the volumetric movement ratio in the air reaches 16% to 25%. Synthetic ammonia is widely used in medical, chemical and gas industries. In the biosphere, ammonia is a product of nitrogen-fixing bacteria activity, nitrogen denitrification, organic nitrogen and animal urine decomposition.

Ammonia pollution source: Expert judgment mainly comes from the concrete admixtures used in construction. There are two main ones. One is to add concrete antifreeze to the concrete wall during winter construction, and the other is to improve the solidification of concrete. Speed, use high-alkali concrete expansion agent and early strength agent. The use of concrete admixtures is conducive to improving the strength and construction speed of concrete. The country has strict standards and technical specifications in this regard. Under normal circumstances, indoor air pollution will not occur. However, in recent years, Beijing has used a large number of high-alkali concrete expansion agents and urea-containing concrete antifreezes. These admixtures containing a large amount of ammonia substances follow in the walls. Changes in environmental factors such as temperature and humidity reduce to ammonia and slowly release from the wall, causing the concentration of ammonia in the indoor air to continue to increase. In addition, the ammonia in indoor air can also come from interior decoration materials. For example, most of the additives and brighteners used in furniture finishing use ammonia water, which has become a necessary commodity in the building materials market.

Ammonia pollution hazard: Ammonia is a colorless gas with a strong pungent odor, lighter than air (specific gravity 0.5). Ammonia is an alkaline substance. It has corrosive and irritating effects on the skin tissues it contacts. It can absorb water in the skin tissues, denature tissue proteins, saponify tissue fats, and destroy cell membrane structures. When the concentration is too high, in addition to corrosive effects, it can also cause cardiac arrest and respiratory arrest through the reverse action of the trigeminal nerve endings. Ammonia is usually inhaled into the human body in the form of gas into the alveoli. After ammonia is inhaled into the lungs, it easily enters the blood through the alveoli, binds with hemoglobin, and destroys the oxygen transport function. Ammonia has extremely high solubility, so it mainly has irritation and corrosion effects on the upper respiratory tract of animals or humans, and weakens the body’s resistance to diseases. A small amount of ammonia is neutralized by carbon dioxide, and the remaining small amount of ammonia is absorbed into the blood and can be excreted with sweat, urine or respiratory tract. Some people may experience symptoms such as skin pigmentation or finger ulcers after long-term exposure to ammonia; after a short period of inhalation of a large amount of ammonia, they may experience tearing, sore throat, hoarseness, cough, bloodshot sputum, chest tightness, difficulty breathing, and may be accompanied by dizziness, Headache, nausea, vomiting, fatigue and other symptoms. In severe cases, pulmonary edema, adult respiratory distress syndrome, and respiratory tract irritation may occur. Therefore, the damage of alkaline substances to tissues is deeper and more serious than that of acid substances.