| Legionella is a gram-negative bacilli which is common in nature and it's usually breed in the circulating cooling water, cooling tower systems, as well as the fountain systems. With the evaporation of these systems, Legionella went into the air by attaching to the surface of aerosol, population who is immunocompromised once inhalated the Legionella may have contracted the pneumonia-like symptoms of legionnaire's disease.Recently, with the development of cities in our country, advanced facilities create favorable conditions for reproduction of Legionella, although they provide suitable life for people. There are more and more chances for people access to Legionella in modern society; it's easier for the outbreak of Legionnaires' disease.The common methods used to control Legionella, such as chlorine disinfection, Copper-silver ionization, ozone disinfection, ultraviolet (UV) disinfection and so on, all have various of limitations. Electrochemical technology is a brand-new water treatment technology. In recent years, electrochemical technology for water disinfection has a considerable development. The applications of the technology have also been used to many fields. Studies have shown that, electrochemical technology can effectively control the formation of bacteria in water.Control the Legionella with electrochemical technology. Found out that the dominant mechanism of this process is the activity substances such as chlorine and oxygen species and by observating the surface of Legionella witch dealing with different sterilization with electron microscopy method, from the micro perspective, found out intuitively that in the electrolysis process, a lot of active substance with strong oxidation generated. On these basises, a lot of one-time dynamic sterilization experiments has done to find the parameters' effecting of sterilizing rate such as intensity of the field processing, the results is that, in dealing with intensity of the field processing of 33.3 mA·h / L, the one-time sterilizing rate reached 99.9%, Moreover, in the same intensity of the field processing, the sterilizing rate of the electric field to the bacteria and Legionella is very close. Sterilized with the current density of 10 mA/cm~2 for 5 minutes, the rates of sterilization with Legionella and bacterium were 72.34% and 74.10%, 10 minutes later, both reached 99.99%, And at the same parameters, the effect of Legionella and bacterium is very similar. And then, a one-time dynamic sterilization experiments has made to find the parameters such as intensity of the electric field processing effects of sterilization, found that, in dealing with the electric field strength with 33.3 mA·h/L, the one-time-killing rate will reach to 99.9%.Given programmers for the Legionella-control, with electrochemical technology, find out that only if the equipment throughput more than the fill water, the system can be balance. Finally, through the design of the new generation of electrochemical device and the effect of the pilot assessment, the feasibility of electrochemical technology used to control the Legionella in the circulating water has been determined. |
