Chemical characteristics and source apportionment of atmospheric precipitation in Baotou urban area
Based on the chemical monitoring of pH,conductivity and ion concentration of precipitation in Baotou area during 2017-2021,the chemical characteristics were analyzed comprehensively,and the source apportionment was revealed using enrichment factor,HSYPLIT and PMF models.Results showed that the annual ranges of pH value and electrical conductivity with precipitation weighted were 6.39-7.28 and 61.76-168.65 μS·cm-1 respectively,indicating that the atmospheric precipitation in Baotou was polluted but not acidified.The main ions of atmospheric precipitation were Ca2+,SO42-,Cl-and Na+,accounting for 76%.Compared with most areas in China,the concentrations of Ca2+and SO42-were higher,indicating that the wind-sand pollution and soot pollution were prominent in the local.The annual ratio of SO42-/NO3-was 4.72,indicating that the precipitation type was still sulfuric acid.The sources of ions in precipitation were easily affected by the short-range exogenous transport according to the backward trajectory of air mass,while the south of Baotou is an important potential source area.Analysis of ion sources showed that in precipitation Ca2+and Mg2+mainly came from dust sources,SO42-and F-mainly came from industrial sources,NO3-mainly came from fossil combustion sources,Na+,Cl-and K+mainly came from sea salt and biomass combustion sources,and NH4+mainly came from agricultural sources.
NETL
NSTL
万方数据
