徐州市大气中二氧化氮浓度特征分析
毕业论文关键词： NO2；徐州；变化特征
Analysis of the concentration characteristics of nitrogen dioxides in the atmosphere of Xuzhou City in 2014
Abstract: Nitrogen oxide can cause atmospheric pollution hazard with formation of photochemical smog, easy to combine with animal hemoglobin in the blood, destroy the stratosphere (the ozone layer in the stratosphere), to be able to convert more toxic nitric acid or a nitrate aerosols, forming acid rain in Xuzhou nitrogen content in the atmosphere and through the analysis of the detection of NO2 concentration change rule (all kinds of nitrogen oxide in the atmosphere can be mutual conversion). NO2 concentration in the atmosphere contains this Xuzhou daily change of the trend, potential changes day by day, and season change the impact of the change of concentration is analyzed. Analysis, Xuzhou atmospheric NO2 pollution is more serious. Nitrogen oxides is the law of the peak is probably every 7 days, this is likely to be affected by human life rule. Week of NOx concentration change were analyzed, and the minimum is NO2 on Sunday, has been slowly increasing, on Friday or Saturday peak, the reason is that the emission source of NO2 city mainly for the automobile exhaust, from Monday to Friday to go to work time, automobile usage, and accumulate large amounts of NO2 are emissions, lead to maximum NO2 concentration on Friday or Saturday, but the weekend after vehicle use reduction, NO2 emissions, atmospheric self-purification ability to highlight effect, the concentration of NO2 on Monday before and after the minimum value. To analyze the diurnal variation of the different weather conditions, it is cloudy conditions, the concentration of NO2 is higher than the concentration of the sunny day, the reason is clear light chemical reaction. NO2 is peak time 23:00-2:00, the reason is the lack of light at night to accumulate; NO2 morning after human activity weakened atmospheric diffusion effect is obvious. And some suggestions are offered according to the analysis of the regularity of measures to control nitrogen pollution.
Keywords: Xuzhou; NO2; variation character
引言
随着生活水平的发展，人们更加关心大气环境质量，对大气环境质量的要求也越来越高，但是伴随着工业的发展，特别是耗能型工业的发展对大气环境造成了严重的危害。海洋、土壤中的有机物在微生物的分解作用下都会释放出氮氧化物，这个过程是属于自然界的氮循环。 人类生产生活过程中排放的NO2，其中绝大部分是来自于化石燃料的燃烧释放热量的过程；也来自生产、使用硝酸的过程，如氮肥厂、有机中间体厂、有色及黑色金属冶炼工厂等,其中以工业窑炉、氮肥生产和汽车排放的氮氧化物量最多。而以化石燃料为燃料的机动车，尾气如果不加以处理其中氮氧化物的浓度很高。汽车尾气是充实大气的重要污染源[1]，城市街道空气NO2污染超过一半来自机动车尾气[2]。目前，徐州氮氧化物污染问题还是比较严重的，造成了严重的环境问题。如不加以控制可能会抵消减排SO2带来的效益。氮氧化物能够损伤人的肺部，让人较难抵抗比如感冒之类的呼吸系统疾病，患有呼吸系统疾病的人受影响尤为严重。同时氮氧化物还是光化学烟雾和酸雨的重要成因，光化学烟雾会损伤眼睛、破坏植物、降低大气能见度，酸雨会破坏建筑、损伤皮肤等好多危害。NO2也会影响城市大气中臭氧的含量，臭氧在低空近地面也是重要污染物。[3]因此氮氧化物存在大气中危害严重，所以监测氮氧化物浓度和其变化趋势就越显得重要。及时监测大气中NO2浓度，对决策部门制定政策，对于城市的管理发展都有着重要的意义。