Analysis On Chemical Characteristics Of Wet Deposition In Four Seasons Of Industrial Area In Jiangbei New District,Nanjing

Wet deposition and wet scavenging as an important feedback atmospheric circulation is an important process of the atmospheric environment and its spatial and temporal changes in physical and chemical properties. This experiment collected rainwater samples continuously in Nanjing North New NUIST sampling site from 2015, the beginning of April to May, 2016, ,sampling synchronization with the collecting samples of atmospheric PM2.5, samples of inorganic ions, soluble inorganic nitrogen and organic carbon were detected and analyzed, while the water-soluble ionic in PM2.5 and gas line change were observed during raining time in spring, 2016 in order to find the detail and feature of atmospheric components changing. Then here comes the following conclusions.There is no obvious acid rain during seasonal sampling period, pH mean is 5.81;although partial high-acid ion concentration, but due to the higher Ca2+, Mg2+ and NH4+ concentration in the rainwater, the acidic substance are significantly neutralized.Secondary aerosol from Anthropogenic emissions contributed most to the chemical composition of rainwater,mainly comprising NH4+, SO42-,NO3-. The K+,Ca2+ and Mg2+ in rainwater mainly from inland, in particular K+ and Ca2+, which marine sources contribute very small; K+ was more from biomass and some from industrial sources; Ca2+ is mainly influenced by dust, industrial combustion coal desulfurization equipment used in limestone is also an important source; source of Mg2+ in addition to most of the earth's crust, sea salt also has more than 10% of their contribution to.F- content of rare and mainly from coal-burning. Precipitation sample accounted for 13% of DOC, as its main source is industrial emissions. Inorganic nitrogen has significant seasonal variation and distribution in rainwater .It's higher in winter, and lower in spring and summer; its main source is also industrial emissionsThe main component of the secondary aerosol NH4+,SO42-, N03- is eliminated after raining and they contribute obviously in the components of the rainwater, Ca2+and Mg2+ has weaker correlation because they should be more associated with the presence of coarse particles. Na+ and K+ will be significantly cleared in precipitation days, but the main source in rainwater is from scavenging in cloud or scavenging in the high altitude below cloud. Meanwhile,continuous observation found wet scavenging on the aerosol composition has better effect,but wet scavenging is not the only reason of the gas removal.