Using cavitation jet technology to degrade organic pollutants in the ocean

　　There are many forms of jets produced by high-pressure cleaners, and they are widely used. Cavitation jets are one of these forms of high-pressure water jets. We all know that cavitation jet underwater cleaning technology can clean up marine organisms attached to hull, the attachments of submarine oil pipeline, etc., but we don’t know that cavitation jet can also degrade organic pollutants in the ocean, so how does cavitation jet degrade organic pollutants in the water? What about pollutants?

　　Cavitation jet is a special form of high-pressure water jet. Cavitation refers to the explosive growth of cavitation bubbles (i.e. gas nuclei, generally less than 20 μm in radius) due to the evaporation of liquid due to local low pressure of liquid flow system (lower than saturated vapor pressure of liquid at the corresponding temperature). When cavitation bubble collapses, it will cause a powerful micro-jet impact, resulting in a very short-lived high-pressure pulse. The tiny space around bubble will form a local hot spot, resulting in extreme high temperature and high pressure, accompanied by complex physical reactions, chemical reactions, mechanical actions, and electrochemical reactions. action and thermal action. According to calculations, when free cavitation bubble collapses, flow velocity of micro-jet near the wall can reach 70 to 180m/s, and the impact force generated on the surface of object is as high as 140 to 170Mpa. The diameter of micro-jet is about 2 to 3μm. The number of jet impacts is about 100 to 1000 times/(s·cm²). The cavitation jet underwater cleaning technology is a new type of underwater facility cleaning technology formed by introducing cavitation into water jet cleaning technology, that is, artificially generating high-density cavitation bubbles in water jet beam, using a large number of cavitation bubbles to the strong micro-jet impact force generated by collapse of local tiny areas on the surface of object can achieve the purpose of cleaning hard dirt and attached sea creatures of the facility.

　　Current theoretical and experimental studies have shown that it is very effective to use the energy of cavitation collapse to degrade organic pollutants in water, and degradation mechanisms are mainly direct thermal decomposition, supercritical water oxidation and free radical reaction.

　　In summary, it is very effective to degrade organic pollutants in the ocean by using the cavitation water jet generated by high-pressure cleaner. As long as the physical and chemical effects produced by high-pressure cleaner are fully utilized, a new field of water treatment technology will be opened up.