| With the rapid economic development and the process of industrialization,the number of motor vehicle has experienced a huge increase and the ozone pollution problem has become more and more serious,which has led to a huge damage on human health,animals,plants and buildings.This paper focus on the increasingly serious problem of ozone pollution in a city of southern China.By using the data of environmental monitoring center and the method of the combination of theoretical research and mathematical statistics,the current status of ozone pollution and ozone generation mechanism can be studied,and propose the measures to control the ozone pollution.The main conclusions are as follows:From 2013 to 2016,in the context of the increasing national ozone concentration,the concentration of ozone in a city of southern China was 136μg/m~3,140μg/m~3,153μg/m~3,and149μg/m~3 respectively.The number of the day of excessive ozone concentration was 17 days,21 days,25 days and 26 days respectively.There was a bad trend on the ozone pollution.According to the monitoring data from March 27,2017 to April 17,2017,the daily variation curve of ozone concentration in the city showed a―single-peak‖pattern.Daytime ozone concentration was higher than at night,and the peak appeared at 15:00.The lowest value appeared at 7:00.Meteorological factors can affect the generation of ozone concentration.There was a positive relationship between ozone concentration and the temperature,and a negative relationship between relative humidity and precipitation.When the wind direction was northwest and southwest,and the wind power was at level 2,ozone can be generated more easily.According to the atmospheric monitoring data in 2015,NO_x and VOCS were important precursors for ozone generation,and when the ratio of NO2/NO in the city was about 5,it was the most conducive to ozone generation.In 2015,the higher concentrations of VOCs species were 2,2-dimethylbutane,propane,ethylene,toluene,n-butane,para-xylene,iso-butane,ethane,benzene,1-hexene,acetylene,1-butene,isopentane,cis-2-butene,ethylbenzene;The VOCs species that contributed significantly to ozone were ethylene,para-xylene,toluene,1-butene,cis-2-butene,trans-2-butene,1-hexene,propylene,2,2-dimethyl Butane,1-pentene,n-butane,o-xylene,isobutane,ethylbenzene,propane.The concentrations of alkanes,olefins and aromatics were 53.6%,22.4%,and 21%,respectively.The contributions of olefins,aromatic hydrocarbons and alkanes to ozone were 57.9%,27.6%,and 14.5%.Olefin contributed a lot to ozone and was the key source of pollution in the city.It was need to strengthen emission control of olefins.Moreover,the radio of VOCs/NO_x in the city was basically smaller than 5.5,and it can be assumed that the ozone was controlled by VOCs.The ozone concentration was affected by seasonal and meteorological factors.At the same time,the ozone concentration at the weekend was higher than the ozone concentration on weekdays.Therefore,people with low immunity should avoid going out in the summer,autumn and weekends,because the radiation was strong.The ozone concentration was affected by seasonal and meteorological factors.At the same time,the ozone concentration at the weekend was higher than the ozone concentration on weekdays.Therefore,people with low immunity should avoid going out in the summer,autumn and weekends,because the radiation was strong.The concentration of ozone pollution in the city presented a regional difference.The concentration of ozone in the industrial areas(G,B)and the old areas(C,D,and A)were relatively high,and the control should be strengthened.According to the city’s ozone pollution situation,the control measures are proposed.The measures mainly includes improving the legal protection,continuing the research on the ozone pollution,strengthening the on-line VOCs monitoring,strengthening the control of VOCs in the key regions and industries,continuing to optimize the industrial structure,controlling the mobile source pollution,and strengthening the regional joint control. |
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