| With the continuous rapid economic development and the approaching of cars entering families, an increasing possession quantity of mobile vehicles is being achieved rapidly in our country. So mobile vehicles are emitting air pollutants increasingly. And the environmental pollution caused by exhaust gas is becoming main environmental problems in large and medium scale cities. Nitrogen oxide (NO_x) pollution level is aggravating in Changchun city, and it has become the second big pollutant inferior to total solid particle (TSP). In order to improve the air quality and make the management foreseeable, precaution and controlling of exhaust gas pollution must be done strategically. Based on the air quality investigation and monitoring, space and time dimension distribution of NO2 was analyzed in the paper. Within the study zone, emission list of fixation and flow resources were found in benchmark year and NO_x distribution rules and pollution shared rate was calculated. Through analysis on structure of pollution resources in Changchun city, combining with general plan, heating plan, control techniques and national policies, ADMS-Urban air diffusion model, the quantity and concentration of mobile vehicles indication pollutant NO_x were predicted. And according to the prediction results, the pollution trend of mobile vehicles exhaust gas was analyzed and the total quantity control goal was given in the paper. Investigation and monitoring results on air quality present condition in Changchun city showed that, in benchmark year 2003, NO_x emission quantity was 57470 t, and the emission quantity was 18730t per year, of which shared rate of mobile vehicles was 32.6%. All kinds of emission resources of whole city contribution to ground air environment was 0.041 mg/m3 and mobile vehicles shared 35.5%.mobile vehicle concentration shared rate was more than emission shared rate, mainly because exhaust gas emission height was low and was difficult to be diffused and be diluted. By the end of year 2003, in Changchun city, the possession number of mobile vehicles was 252900 and the average increase rate was 16.9% in recent 5 years. According to the main domestic cities mobile vehicles actual increase situation and the prediction results in recent years, combining with Chinese car development plan, in the near future 10～15 years, the increase rate will be 15% or so for small cars, 6～9% or so for large truck while 12% or so for motor cycle in 2～3 years and after 4 years this increase trend will decline a bit and abate, then average increase rate will decline to 8～10%. With the possession quantity of mobile vehicle increase yearly, the exhaust gas emission will increase slowly. By the year 2010～2015, NOx emission shared rate of mobile vehicles will be 47.7% and 58.8% respectively, then the concentration of NOx in the air of Changchun city will reach 0.061mg/m3 and 0.077mg/m3, of which mobile vehicle shared 52.2% and 64.4% respectively. Controlled by standard of Zone II yearly average value 0.1 mg/m3 and based on background concentration of NOx in air and fixation emission resources effect on air quality in Changchun city, total quantity control goal value 58000t per year of NOx mobile vehicles emission was predicted and the number of possession of mobile vehicles should be controlled within 1310000. According to the prediction results and emission trend of...
|
PDF Full Text Request