What are the modes of ozone generation? How to detect the ozone concentration in water?
Mode of ozone generation
The technology of preparing ozone by electrolysis was founded in 1840, mainly through the use of low-voltage direct current to electrolyze water, so that water can be oxidized at the anode solution interface to produce ozone. The ozone preparation device is composed of electrolyte solution and cathode and anode. Ozone is separated from the anode, and the cathode can be divided into two types, namely, hydrogen evolution cathode and oxygen reduction cathode.
Also called silent discharge method (DBD method for short). Corona is generated in the gas by alternating high voltage electric field. Free high-energy electrons in the corona dissociate oxygen molecules and polymerize into ozone molecules through collision. The dielectric barrier discharge method has the advantages of relatively low energy consumption, large single unit ozone output, and dry air, oxygen or oxygen rich gas with high oxygen concentration can be used as the gas source. Therefore, this method is mostly used in industrial ozone synthesis.
Ultraviolet irradiation is to use ultraviolet ray to irradiate the dried oxygen, so that some oxygen molecules are activated and dissociated into oxygen atoms, thus forming ozone. The disadvantages of ozone produced by ultraviolet irradiation method are high energy consumption and low ozone concentration. Therefore, it is unrealistic to use ultraviolet irradiation method to produce ozone in large quantities. It is only suitable for various tests with small amount and low concentration requirements.
Radiochemical method is to use nuclear radiation of various radioactive sources to dissociate oxygen molecules to generate ozone. There are two processes for industrial ozone production in this method. One is the contact of oxygen with fission products, and ozone is generated by thermal collision of radiation, oxygen with fission products and secondary radiation. Second, ozone is generated only under radiation. This method has high cost and poor safety due to the use of radioactive sources.
Ozone produced by low pressure electrolytic water technology can replace existing chemical agents. It can achieve rapid "disinfection and sterilization, deodorization and deodorization, antisepsis and mildew removal, toxin decomposition, food preservation, water purification, air purification, bleaching and decolorization" and other effects. At the same time, it can save disinfection costs, have no harmful chemical residues, and be non-toxic and harmful to people. It can be widely used in "industry, agriculture, medical treatment, transportation, environmental protection, home, public health, food processing, surface disinfection, healthy life and other fields.
With the development of industry, ozone is widely used in drinking water, sewage, industrial oxidation, food processing and preservation, pharmaceutical synthesis, space sterilization and other fields. Because ozone is mainly used for disinfection and sterilization in these fields, the detection of ozone concentration becomes particularly important.
How to detect the ozone concentration in water?
Ozone concentration detection methods can be roughly divided into "chemical analysis method", "physical analysis method" and other detection methods. With the continuous development of technology, detection methods and instruments are also changing.
Use different ozone electrodes according to different occasions
Constant voltage platinum electrode (conventional)
It can not be used in the environment of electrolytic method. This method will produce a large number of H+hydrogen ions in water, which will affect the platinum ring. (Solution: add oxygen into the water, or shake and stir to let the oxygen in the air enter the water and react with H+to generate water).
Constant voltage gold electrode
It can be used in any ozone generating environment. At present, no environment can be used.
Polarographic ozone electrode
It can be used to measure ozone, electrolytic environment and the environment with ozone gas.
Disadvantages: polarization is required and electrolyte is added.
How to select ozone detector
The ozone detector of Noble Technologies, DOZ-7600, is a microcomputer based online measurement and control instrument for ozone in water. It uses advanced non membrane constant voltage sensors, without changing membranes and reagents, and has high sensitivity. It is also equipped with power failure protection, RS485 communication and other functions. The core devices of well-known foreign brands are used, and a series of advanced analysis technologies and ring temperature compensation technologies are used to ensure the remarkable advantages of the instrument in long-term stability, accuracy, fast and real-time detection of ozone concentration.