Analysis On The Change And Assessment Of Air Pollution And Its Influencing Factors In Cities Along The Yangtze River Of Jiangsu Province

With the rapid economic development and urbanization, a large amount of various pollutants have been discharged into atmosphere, leading to an intense concentration of such substances. The compound atmospheric pollution and haze are thus generated. Compound atmospheric pollution has lots of manifestations as a phenomenon, such as the intensification of atmospheric oxidation, notable declining of atmospheric visibility and the spread of environmental deterioration, and in its essence the interexchange of source and target pollutants, coupling interactions of polluting transferring processes as well as the synergistic effect on the environment. The monitoring activities in Beijing-Tianjin-Hebei Region, Yangtze and Zhujiang Region have shown the coexistence of intensifying particulate matters and air pollutants, especially the oxidizer, forming obvious traits of compound air pollution which is increasingly grim in levels in economically developed areas of China.The coastal area of Jiangsu Province is known as the one of the most developed and populous regions in China. Since the beginning of the 21st century, the process of industrialization and urbanization has been even faster, thus bringing the increase of discharge of industrial waste gas, vehicle exhausts, atmospheric aerosols and the atmospheric concentration of substances such as SO2, HC, NOx and particulate matters are correspondingly raised. The photochemical air pollution with O3 as its form and haze which is manifested by particulate matters have grown even more serious, changing the chemical structure of the atmosphere above these areas which boasts a particular compound air polluting landscape with coal-and-smoke and vehicle exhausts. This phenomenon is displayed with obvious traits of regional pollution alongside the coupling interactions of pollutants, featuring a high frequency of photochemical and high ozone pollution.To study the cause of haze and to explore the preventive and curative measures of it, this paper mainly discusses the comprehensive assessment of the evolvement rule of haze and the monitoring norm of its current situation. Three primary tasks are to be fulfilled in this paper. First, analyze the historic data and study the regional compound air pollution and its evolvement rule. Second, determine the active pollution factors in these areas to explain the current situation of compound air and haze pollution. Third, conduct surveys on sources and causes of pollution in cities along the Yangtze River with the water soluble ionic concentration as a main reference, focusing on the industrial discharge into the atmosphere. The study has shown that:1.Eight cities along the Yangtze River all reported improving tendency yet not notable in air quality during the period of 2001 to 2010. The concentration of PM10、SO2has been declining with PM10 still a primary pollutant while no visible change of NO2 has been detected, not only that, its polluting weight on the atmosphere is even higher. The above-mentioned substances shows a similar change trend, with its intensity higher in winter and autumn and lower in summer as is shown in the frequency of acid rain in Suzhou, Wuxi and Changzhou which are located in the economically developed region of Jiangsu.The concentration ratio of SO42-/NO3- contained in precipitating water has notably declined, with SO42- lower and NO3- higher during that time span. This phenomenon has a bearing relationship with the dwindling discharge of SO2 but an abrupt increase of vehicles and the relevant backward in the de-nitrification technology of industrial enterprises.2. In the year 2011 and 2012, the above mentioned 8 cities detected peaking degree of pollutant substances such as SO2, NO2, PM10, PM2.5 due to climatic conditions, outer and local pollutant sources. This area is easily affected by Southern bound dust and the combustion of straw in summer days when the climate tends to be hot and humid therefore a relatively low level of such pollution is expected, however a higher and sometimes even excessive level of oxidizer could be monitored in the atmosphere.3. Haze poses a main obstacle to the treatment of atmospheric pollution in cities along the Yangtze River, with the impact of which higher in Southern Jiangsu than its Northern part, notwithstanding a medium level of air pollution was detected in Nanjing. Haze appears oftentimes in the Autumn and Winter and that is related to climatic conditions.The cold air flow and high pressure lead to a comparatively stable atmospheric structure that contains the dilution of pollutants, also, various wastes discharged as a result of domestic heating add to the haze. As particulate matter is a main source of haze, thus it seems not difficult to draw to a conclusion that NOx bears a close relationship with haze only through further analysis of the concentration of various pollutants, therefore, it is necessary to control the discharge amount of vehicle exhausts amongst other waste materials.4. The sources of four main pollutants found in cities along the Yangtze River of Jiangsu all differ. The concept of motor vehicles in the urban area contains small cars and motors, and these two transportation tools mainly produce CO and HC while TSP and NOx are overwhelmingly provided by medium and large sized vehicles.5. Four intensified monitoring activities show that water-soluble ions exist in forms of nitrate, sulfate and ammonium and the ratio of NO3-/SO42- appears close featuring a synergistic trait.