Pollution Characteristics Of Inhalable Particulate Matter And Fog Water Of Chongqing Urban Section

With the incessant exacerbation of human activities, the influence on climate, environment and human health because of the increasing air-borne particulates has drawn people's attention increasingly. And the city atmosphere particulates pollution has become a popular research issue. The problem of atmosphere particulates pollution in china is so serious that the chief atmosphere contaminant in most days of a majority of cities is PM10. The mean values of Chongqing from the year of 2000 to 2003 basically kept around 150ug/m3, which exceeded 50% of the secondary grade of national air-quality criterion. Therefore, it is greatly important and necessary to sample the PM₁₀ and fog water of Chonqging urban section and analyze the whole sample. This paper focus on the current pop issue and front problem of city air pollution, and through systemic field sampling, observation and indoor analysis, the physico-chemical characteristics of particulates, fog, fog water and rain water and the resources of particulates have been studied in entirety. The main contents are included as follows: (1) The research of the variation law of PM10 concentration as time and space. It discusses PM₁₀ in different season and different period of a day and the pollution level variation in Chongqing urban and remote suburb cleanness contrast spot. This study investigates according to the questions above, and discusses air PM₁₀ of Chongqing , time and space variation rule and the influence about the gas factors to particulates pollution. The research result demonstrates that : The mean concentration of PM10n urban section and in Jinyunshan cleanness contrast spot are respectively 159μgm^-3 and 64.3μgm^-3. Both of the particulates concentration in the two sampling location in urban are 0.06 times more than the secondary grade of national environmental air-quality criterion and 2.43 times more than the concentration of Jinyunshan cleanness contrast spot. Seasonal variation of the atmosphere particulates pollution level both in urban section and cleanness contrast spot is obvious. The highest concentration of PM₁₀ of the two sampling location in urban section appear in winter, which is similar to the location of cleanness contrast spot, and the lowest concentration of the two sampling location in urban section appear in summer while the lowest concentration in the cleanness contrast spot appears in spring. The average density number of air particles is 799.3 per cubic centimeter, the highest density number is 1103.8 per cubic centimeter and the lowest density number is 325.5 per cubic centimeter. Compared with the values of about ten years ago, the number of the particle the size of which is over 0.3μm increased 2.2 times. Daily variation of particle density number is obvious. The concentration value is relatively high in night and morning, and lesser in the afternoon. The particles with the size between 0.5-0.8μm are the main contributor for the visibility decrease . (2) The research of the chemical character of PM10. It investigates the constitution of the deleterious metal on the surface of the particulates belongs to different source and analyzes the content of the dissolvable inorganic component in the atmosphere particulates of Chongqing using the ion color spectrum. The research result demonstrates that: The element concentration of total sample Fe granule is the highest among the all 19 element, next is Zn and Pb. The content of the dissolvable and total sampling microelement in the sample of PM10 which is sampled in traffic artery is obviously lower than the 9 kinds of dissolvable microelement in the environment atmosphere PM10. The average annual concentration of PM10 water-soluble anions are respectively Na+0.19μg/m3, NH4+ 3.26μg/m3 ,K+1.92μg/m3 and Ca2+10.54μg/m3. The concentration of Ca2+ is the highest of the four anions which is respectively 55.5, 3.23, 5.5 times of the other three cations. The average annual concentration of water-soluble anions are respectively Cl-2.07μg/m3,NO3-5.39μg/m3 and SO42-17.16μg/m3. The concentration of SO42-is the highest, which is 8.3 times of Cl-and 3.2 times of NO3-. No matter the urban section or cleanness contrast spot, The ratio of [NO3-]/[ SO42-] is relatively small which indicates that the air pollution is mainly caused by fixed pollution resources. (3) The research of physical and chemical characteristic of fog. It mainly includes the fog sampling, the observation of the distribution of the fogdrop spectrum and the characteristic of the quantity of the containing water and the chemical component of the fog water as well as the research of the relationship attaching these mentioned above with the atmosphere visibility and the atmosphere polluted condition. The research result demonstrates that: The density number of fog droplet increased ten times compared with the value of about ten years ago, the average diameter of the fog droplet decreased 2.8 times and the moisture containing in the particles increased three times. Analysis of the results shows that all the ions concentration of fog water is much higher than that of precipitation. (4) The analytical research of the. It adopts the chemical mass balance particulatessource analytical model to discuss the contribution proportion to the atmosphere made by the human activity of burning coal, traffic, transportation, construction and so on. The research result demonstrates that: Sources analytical model indicates that fugitive dust, construction dust and smut are the important sources which influence Chongqing atmosphere particulates pollution status. The innovated point of the research of this paper: (1) It is combined with the current pop research issue of the urban atmosphere pollution "The pollution characteristic of the urban particulates and the controlling technology and the policy"which is the worldwide research problem to integer the particulates, the fogdrop spectrum, the fog water and the rainwater for the first time in Chongqing. (2) It comprehensively and systemically investigates the mass concentration of the inhalant atmosphere particulates, the time and space distribution characteristic of the chemical component and the constitution of the source of the particulates, and proposes the controlling countermeasure of the particulates pollution which has the significant academic supervising meaning to the treatment of the urban particulates pollution. (3) Besides analyzing and improving air particles spectrum fitting and the computing methods to the visibility influence, it fist concludes that the main source of the urban inhalant particulates of Chongqing is the raising road dust, the construction dust and the burning coal dust has the academic proof by using the chemical mass balance analytical model of the particulates source to compute.