Ozone is a strong oxidant, with strong sterilization, bleaching, deodorization and other characteristics, so it is widely used in water disinfection, food processing sterilization and purification, food storage, medical and health and household disinfection purification products. In the production and application of ozone generator, a certain ozone concentration is an important parameter to ensure the disinfection and oxidation effect, save energy and prevent pollution. How to detect the concentration of wastewater ozonizer?
1. The concentration of ozone should not be too high
Ozone is not only beneficial to human body, but also a kind of environmental pollution substance. China's ambient air quality standard (GB3095-1996) stipulates that the concentration limit of ozone (average 1 hour) is 0.12mg/m3; the secondary standard is 0.16mg/m3; the third standard is 0.20mg/m3. In most countries, the upper limit of the industrial hygiene standard for ozone is 0.1ppm (0.20mg / m3). Therefore, the ozone sterilization concentration of sewage ozone generator should not be too high, and the output of ozone generator should not be as high as possible. For example, the output of ozone generator for indoor disinfection in general family should be about 200mg / h, which should not exceed 400mg / h. In this way, after 30 to 60 minutes of ozone sterilization, the indoor residual concentration is lower than the requirements of domestic health standards for fruits. It should be pointed out that some allergic people may suffer from skin irritation, dyspnea, cough and rhinitis after long-term exposure to ozone levels of more than 0.18 mg / m3. No matter how high the concentration is, it will cause more damage to the skin.
2. Ozone application engineering and equipment need to monitor the ozone concentration. The ability of ozone generator to generate ozone is largely affected by air source humidity, cooling water temperature and aging of discharge surface. Therefore, the ozone concentration must be checked regularly. For large-scale ozone equipment, a high concentration ozone (gas) detector, a dissolved ozone detector to detect mixed water, and a detector to detect the ozone concentration in the exhaust gas are equipped in the process. In order to control the whole system in good working condition.
3. Calibration of sewage ozone generator output
The ozone output of sewage ozone generator is an important and basic technical index, and its output is calculated by measuring the ozone concentration. Strictly speaking, if there is no reliable method to determine the concentration of ozone, it is impossible to produce qualified products. The current ozone generator output and ozone concentration are not reported on the market.
4. Ozone concentration ensures disinfection effect
The killing effect can only be achieved under the same condition as other disinfectants and after reaching a sufficient dose and acting for a certain period of time. For example, when the ozone concentration is 0.08-0.6ppm, the effect on E.coli in the air lasts for 30 minutes, and the average killing rate is 84.60-99.9%. When the ozone concentration in the air is 0.34-0.85ppm and the effect is 10-30min, the killing rate can reach 99.47-99.97%. Another example is that when ozone disinfects the air, when the concentration is 0.21 mg / L, the killing rate of Staphylococcus aureus reaches 90.81%. If the concentration increased to 0.72 mg / L, the action time was still 10 min, and the killing rate was as high as 99.99%.