摘要
基于 2017-2021年间对包头地区降水pH、电导率及离子浓度的化学监测,综合分析市区内大气降水的化学特征,并采用富集因子、HSYPLIT和PMF模型等方法揭示降水离子组分来源.结果表明,5年间降水量加权pH和电导率年际变化为 6.39-7.28 和 61.76-168.65 μS·cm-1,降水整体清洁程度差但无酸化现象.大气降水主要离子为Ca2+、SO42-、Cl-和Na+,占比 76%,其中Ca2+和SO42-浓度高于我国大部分地区,表明当地风沙型污染和煤烟型污染问题突出.降水中SO42-/NO3-年均值为 4.72,降水类型依旧为硫酸型.气团后向轨迹显示包头地区降水离子组成来源具有近距离外源输送的特征,且包头以南区域是重要的潜在源区.离子来源解析表明降水中Ca2+和Mg2+主要来自扬尘源、SO42-和F-主要来自工业源、NO3-主要来自化石燃烧源、Na+、Cl-和K+主要来自海盐及生物质燃烧源、NH4+主要来自农业活动源.
Abstract
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.
基金项目
内蒙古自然科学基金(2021BS08013)
2023年内蒙古自治区级大学生创新创业计划训练项目(S202310131021)
包头师范学院科研项目(BSYKJ2022-ZQ03)
NETL
NSTL
万方数据