Research And Application Of Ozone Concentration Online Monitoring System

According to the monitoring status of 74 City air quality environmental protection department released in July 2013, in May, the pollutants in many areas of ozone instead of PM2.5 took the top spot, for example, pollutants based on PM2.5and ozone in Beijing, Tianjin and Hebei region, pollutants based on ozone and PM2.5 in the Yangtze River Delta region, as well as pollutants only based on ozone in the Pearl River Delta region. In the city in 74, the maximum ozone concentration on the mean(every 8 hours) exceed the standard average percentage of up to 26.9.There are two ozone precursors, a volatile organic compound and a nitrogen oxide,if these two substances are irradiated by light in the air, the chemical reaction occurs to produce ozone, the more ultraviolet radiation, which produces more. Because of its strong oxidation, it can accelerate other substances into PM2.5, for example, it will accelerate the transformation of sulfur dioxide into sulfate, will accelerate the transformation of nitrogen oxides into nitrate, will accelerate the oxidation of volatile organic compounds into two organic aerosols, which will become parts of the PM2.5 having a great impact on human health.In this paper, the on-line monitoring of ozone is realized by using Fourier transform- differential absorption spectroscopy. Then the test systems include the ozone standard gas generating system, the on-line monitoring system of the ozone concentration in laboratory, the online monitoring system of portable ozone concentration and the air discharge simulation experiment system, and each part of the system are introduced in detail. For ozone at room temperature is not biodegradable, easy storage, no corresponding standard gas, so we created ozone standard gas generating system, the accuracy is 0.1 ppm. According to the characteristics of ozone absorption spectra, the 7IPX150 UV xenon light source-7ISW501 three grating scanning monochromator system is used for measuring optical research, the ozone concentration inversion bands determined are Hartley with 250-260 nm and Huggins with 320-350 nm, the characteristics and the concentration inversion of 320-350 nm and 250-260 nm were analyzed by using co-correlation and Fourier transform-differential absorption spectra, and the corresponding concentration inversion equation was established; In order to makethe device can highly integrated and applied to practical environmental monitoring,the pulse xenon lamp-fiber spectrometer is adopted to create a portable ozone concentration online monitoring system, and develop the software system for automatic monitoring of ozone(O3). The on-line monitoring system of the portable ozone concentration is applied to the air discharge simulation experiment successfully, the ozone concentration in the four discharge models including the surface discharge model, the air gap discharge model, and the metal particle discharge model is monitored on-line, obtaining the curve of ozone concentration.