Chemical characteristics and source apportionment of precipitation in Weinan City
Based on the monitoring and analysis of pH,conductivity,and ion concentration(F-,Cl-,NO3-,SO42-,Na+,NH4+,K+,Mg2+,Ca2+)of precipitation in Weinan City from 2017 to 2021,corre-lation analysis and PMF model were used to analyze the source of ion components.The results showed that the 5-year average weighted pH and conductivity of precipitation at urban and rural stations were 6.14 and 6.12,141.4μS/cm and 137.9µS/cm,respectively.Although there was no acidification phenomenon,the degree of precipitation pollution was relatively severe.The main ions Ca2+,SO42-,NH4+,and NO3-in urban stations account for 26.0％,24.9％,15.0％,and 10.1％of the total ion con-centration,respectively.In rural stations,the main ions Ca2+,NH4+,SO42-,and NO3-account for 26.6％,23.3％,22.1％,and 15.1％of the total ion concentration,respectively.The total ion concentra-tion in urban stations is higher than that in rural stations.Over the past 5 years,the SO42-/NO3-levels were between 0.5 and 3.0,and the pollutant emissions were classified as a mixture of sulfuric acid and nitric acid.Correlation analysis shows that the correlation coefficients between SO42-and NO3-,Ca2+and Mg2+,Cl-and Na+are relatively high,indicating they have related sources.The correlation of Ca2+with SO42-and NO3-is greater than that of NH4+with them,indicating that Ca2+has a greater neutralizing effect on acidogenic anions SO42-and NO3-than NH4+.The PMF source apportionment effect is good,and the apportionment results show that atmospheric precipitation ions mainly come from sea salt,agricultural emissions,motor vehicle emissions,biomass combustion,dust,industrial emissions,and fossil fuel com-bustion;Ca2+mainly comes from dust(51.10％),NH4+mainly comes from agricultural activity(68.60％),SO2-mainly comes from industrial emissions and fossil fuel combustion(44.00％),and NO3 mainly comes from motor vehicle emissions(67.00％).
万方数据
维普
