Liquid ammonia is a colorless gas with a strong, pungent odor. It is volatile at room temperature and chemically reactive. When liquid ammonia leaks, it poses a serious threat to the environment and human health. First, leaked liquid ammonia rapidly vaporizes in the air, forming a large amount of ammonia gas. Contact with ammonia gas causes severe irritation and corrosion to the skin, eyes, and respiratory tract. Mild exposure may cause symptoms such as eye irritation, tearing, coughing, and sore throat; severe exposure may lead to respiratory inflammation, pulmonary edema, and even death. Furthermore, liquid ammonia leaks damage the surrounding ecosystem, such as polluting soil and water bodies, affecting plant growth and aquatic life.
II. Emergency Response Principles for Liquid Ammonia Leaks Emergency response to liquid ammonia leaks should adhere to the principles of "rapid response, safety first, and scientific handling." Rapid response means that upon discovering a leak, relevant personnel must take immediate action to prevent further escalation. Safety first emphasizes ensuring the safety of rescue personnel and surrounding residents during the handling process, and preventing secondary accidents caused by improper handling. Scientific handling requires taking reasonable and effective measures based on the physicochemical properties of liquid ammonia to minimize the harm to the environment and personnel caused by the leak.
III. Emergency Response Measures at the Leak Site
(I) Personnel Evacuation and Warning
Upon discovery of a liquid ammonia leak, on-site personnel should be evacuated immediately. During evacuation, the direction should be determined based on wind direction, generally moving upwind of the leak point to avoid inhaling leaked ammonia gas. Simultaneously, a warning zone should be established, prohibiting unauthorized personnel from entering the leak site. The extent of the warning zone should be determined comprehensively based on the severity of the leak and factors such as wind direction and speed. Typically, a warning zone should be established within tens or even hundreds of meters of the leak point to prevent accidental entry and injury.
(II) Cutting Off the Leak Source
If the leak source is equipment such as storage tanks or pipelines, measures should be taken as soon as possible to cut off the leak source. For storage tank leaks, the relevant valves can be closed to stop further leakage of liquid ammonia. For pipeline leaks, in addition to closing valves, temporary sealing tools can be used for plugging. During the process of cutting off the leak source, rescue personnel must wear protective equipment, such as chemical protective suits and positive pressure breathing apparatus, to prevent injury from liquid ammonia.
(III) Ventilation and Dilution of the Leak
Ventilation and dilution at the leak site are key measures to reduce the concentration of ammonia. Existing ventilation equipment, such as exhaust fans and ventilation ducts, can be used to expel the leaked ammonia outdoors. In the case of an outdoor leak, fire hoses can be used to spray a mist of water to dilute the leaked ammonia. The mist of water reacts with the ammonia gas to form ammonia water, thereby reducing the concentration of ammonia in the air. It is important to note that during the dilution process, large amounts of ammonia water should be avoided from flowing into water bodies, causing water pollution.
IV. Cleanup and Follow-up Treatment after the Leak
(I) Cleanup of Leaked Materials
After the leak is brought under control, the leaked liquid ammonia and ammonia gas need to be cleaned up. For leaked liquid ammonia, specialized adsorption materials, such as activated carbon and vermiculite, can be used to adsorb it and collect it. For ammonia water on the ground, neutralization methods can be used for treatment. For example, dilute hydrochloric acid or sulfuric acid solution can be used to react with ammonia water to produce harmless ammonium chloride or ammonium sulfate, which can then be properly disposed of.
(II) Environmental Monitoring and Assessment
After the leak is handled, the surrounding environment should be monitored and assessed. Monitoring includes the concentration of ammonia in the air, and the pollution levels of soil and water. The monitoring data will be used to assess the environmental impact of the leak and determine whether further environmental remediation measures are necessary. For example, if the soil is severely polluted, soil replacement or chemical remediation may be required; if the water is polluted, water purification treatment may be necessary.
(III) Accident Investigation and Summary
After the liquid ammonia leak is handled, an accident investigation should be organized. The investigation will include the cause of the leak and lessons learned during the handling process. Through the accident investigation, experiences can be summarized, emergency plans improved, and similar accidents prevented from recurring. At the same time, the performance during the accident handling process should be evaluated, outstanding personnel commended and rewarded, and shortcomings addressed.
Liquid ammonia leaks are serious safety accidents, but their harm can be minimized by following scientific and reasonable procedures. During the handling process, personnel safety is of paramount importance, while environmental protection and post-accident management must also be emphasized in order to effectively respond to liquid ammonia leak accidents.
