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Shanghai, as China's economic, financial, trade and shipping center, with the accelerated process of urbanization, the expansion of the size of the population, as well as car ownership continues to increase, the problem of acid rain pollution increasingly severe urban ecology, to avoid acid rain pollution problem, the population inflict more damage and economic development, should be strengthened and in-depth information on the monitoring of the content of toxic and hazardous substances in Shanghai meteoric research and Source Apportionment. Based on this, we start from the season change monitoring the chemical ingredients of the Shanghai meteoric study of Shanghai atmospheric precipitation acidification pollution causes and the status quo of heavy metal pollution, dissolved organic carbon and total nitrogen content and wet deposition season variation, as well as 7Be and 210Pb content and wet deposition fluxes of seasonal variation of precipitation, while taking advantage of the correlation analysis, principal component analysis, sea salt tracer method, air mass backward trajectory model natural radionuclides 7Be and 210Pb method to tracer Shanghai City of precipitation mainly overcast, the source of the cation. Through the above research, draw the following conclusions: 1. Shanghai atmospheric precipitation pH value has a significant seasonal variation, winter and spring, summer and autumn, the overall low pH value, the annual average pH value only 4.35, below the standard of acid rain (pH <5.6), the growing problem of acid rain pollution. 2 the size of the order of the rain water soluble ion concentration of SO42-gt; NH4 gt; Ca2 gt; N03-gt; Cl-gt; of Na gt; Mg2 gt; K gt; F; SO42-, N03-, Cl-ion years concentrations were 109.46,44.76 and 36.23μeq / L, NH4, Ca2 and Na ion concentration were 90.02,87.84, and 25.71μeq / L; equivalent ratio of 2009 to 2010 in Shanghai, the average annual precipitation SO42-/NO3- was 2.45, indicating that Shanghai acid rain as sulfuric acid and nitric acid compound; the 1999-2009 Shanghai precipitation in SO42-/NO3 when the ratio has maintained a downward trend, the ratio has declined from 644 in 1999 to 2009 2.45 This shows that in recent years, Shanghai atmospheric NOx pollution relative to SO2 pollution getting serious; 1999-2009 Shanghai precipitation (Ca2 NH4) / (SO42-NO3-) equivalent ratio showing a trend of increased and then decreased This shows acidic pollution of the recent years, Shanghai meteoric exacerbate urban air in alkaline particulate matter reduction in certain relations. Shanghai atmospheric precipitation the heavy metal elements of Al, Zn, Fe, Mn, Pb and Cu concentration is high, the volume-weighted average (VWM) 69.75,58.16,38.38,11.57,11.10, and 4.28μg.L-1 Shanghai atmospheric precipitation, Pb and Zn content exceeds the limits for heavy metal content of surface class I water other heavy metals were not exceeded, Pb and Zn in Shanghai meteoric. 4. Shanghai rainfall samples soluble organic carbon (DOC) content in the range of 1.36-12.52mg / L, the annual average content of 2.80 mg / L and the annual soluble nitrogen content of 3.31 mg / L, nitrate annual average content of 0.56 mg / L, the annual ammonium nitrogen content of 1.07 mg / L, the average annual organic nitrogen content to 1.68 mg / L, the average annual precipitation total nitrogen Shanghai content of 3.31 mg / L Class V was significantly higher than the surface water and total nitrogen content of the required water quality standards, which shows the total nitrogen content in the Shanghai meteoric seriously overweight, the greater the role of surface water pollution of drinking water sources, Shanghai. 5 Shanghai precipitation 7Be concentration range of 0.47-5.99 Bq / L, the annual volume-weighted average concentration of 1.46 Bq / L; the the 210Pb concentration range for the 0.06-0.90Bq / L, the annual volume-weighted average concentration for 7Be and 210Pb concentration of 0.26 Bq / L; Shanghai precipitation has the same seasonal variation: the high concentration of winter and spring, the lowest concentrations in summer and autumn, the concentration of the intermediate; precipitation 7Be annual wet deposition flux 1834.24 Bq-m-2 · yr-1; wet deposition fluxes of precipitation 210Pb years 295.98Bq · m-2 · yr-1; Shanghai meteoric 7Be and 210Pb wet deposition, respectively, of the total atmospheric flux settlement 89% and 62% of the flux and dry deposition to the total deposition fluxes of 11% and 38%, 7Be by wet deposition to surface subsidence, 210Pb by wet deposition and surface subsidence, and by dry deposition to surface deposition, wet deposition contribution is greater than the dry deposition; Shanghai atmospheric precipitation 7Be and 210Pb concentration ratio 7Be/210Pb range 2.61-25.77, the annual average of 6.72, the spring precipitation 7Be/210Pb the average ratio was significantly high another three seasons, it can be inferred Shanghai there in the spring senior atmospheric transport to the near-surface \6. Shanghai meteoric Mn, Zn, Sr, Cu, Cd, Ni may be mainly derived from soil dust; Fe, Al and Pb may be mainly from the industrial activities of direct emissions or coal-fired emissions; S042-, NO3- , the Ca2 mainly of anthropogenic contributions, Mg2, K crustal source contribution, Na, Cl marine source contribution; the northwest air mass sources in precipitation N03-, SO42-, NH4, average concentrations derived from marine direction precipitation precipitation air mass ion concentration significantly overall lower than the concentration of ions in the continental air mass of the source of the rainfall brought precipitation, this description of the chemical composition of precipitation in Shanghai is not only influenced by local sources of pollution, but also by its northwest and southwest direction over the continent of the long-range transmission of pollutants. 7.7Be N03-, SO42 and NH4 correlation of better, 210Pb and S042-and NH4 correlation of better long-range land-based sources of atmospheric pollutants, 7Be and 210Pb concentrations in the highest concentration of winter and spring, indicating The transmission is one of the important reasons that caused the precipitation in Shanghai acidic pollution; 7Be as A Tracer and 210Pb and SO42-correlation coefficients were significantly greater than 7Be and 210Pb with a correlation coefficient of NO3-, long-range land-based sources of atmospheric pollutants transmission The contribution of contribution is greater than the concentration of NO3-SO42-concentration of atmospheric precipitation in Shanghai; 7Be/210Pb F is a strong correlation, while the poor correlation with the other constants of anion and cation, the upper atmosphere vertical up the transport and surface natural source emissions of substances Shanghai meteoric ion sources contribute little, while the long-distance transmission and local anthropogenic emissions of land-based sources of air pollutants effect.
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