Application of Liquid Oxygen in Wastewater Treatment plants

Ⅰ. The Role of Liquid Oxygen in Wastewater Treatment Plants 

During the wastewater treatment process, large amounts of organic compounds and elements such as nitrogen and phosphorus are discharged into the water, causing pollution to the aquatic environment. To reduce pollution, bio-treatment is typically carried out. Bio-treatment utilizes biological principles, using microorganisms to remove pollutants. Biological treatment requires air to provide oxygen for microbial respiration and metabolism. In traditional biological treatment systems, gas generators or air blowers are used to supply the necessary oxygen to microorganisms. However, this method has some drawbacks, such as high operating costs, large energy consumption, and maintenance difficulties. The application of liquid oxygen can help solve these problems. Liquid oxygen is a liquid with extremely low temperature (-183°C) that contains a high concentration of oxygen. Injecting liquid oxygen into the wastewater treatment reactor can provide a large amount of oxygen, facilitating microbial respiration, organic matter degradation, and the removal of nitrogen, phosphorus, and other elements. Additionally, the low temperature of liquid oxygen can reduce the reactor's temperature, enhancing the survival and efficiency of microorganisms.

Ⅱ. Methods to Increase Reactor Treatment Capacity with Liquid Oxygen 

The use of liquid oxygen can increase the treatment capacity of the wastewater treatment reactor. The specific method is to increase the aeration area of the reactor and replace air with liquid oxygen. Experiments have shown that under certain conditions, replacing traditional air blowers with liquid oxygen can increase the treatment capacity of the wastewater treatment reactor by 1.5-2 times. Furthermore, liquid oxygen can be used simultaneously with other gases. After injecting liquid oxygen into the reactor, the demand for air can be reduced, lowering operating costs and energy consumption while improving treatment efficiency. However, safety concerns need to be considered during process design.

Ⅲ. Comparison of Liquid Oxygen with Other Gases 

Compared to oxygen gas, liquid oxygen has the following advantages:

1. Provides higher oxygen concentration, which can increase reaction rates and reduce energy consumption.

2. Low temperature of liquid oxygen can reduce reactor temperature, enhancing microbial survival rates.

3. Liquid oxygen is easy to operate and does not require complicated equipment or maintenance.

In conclusion, the application of liquid oxygen in wastewater treatment plants is widespread, improving treatment efficiency and reducing operating costs. However, attention must be paid to safety during operation to ensure a safe and reliable process.