安阳市夏季道路积尘水溶性离子污染特征及来源分析

Pollution characteristics and source analysis of water-soluble ions in road dust in Anyang city during summer

为了解安阳市夏季道路积尘水溶性离子污染特征及来源,于2020年5月使用手持式便携吸尘器采集70个城市道路积尘样品,经离子色谱仪测定其中10种水溶性离子(F^(−)、Cl^(−)、NO2−、NO_(3)^(−)、SO_(4)^(2−)、K^(+)、Na^(+)、Ca^(2+)、Mg^(2+)、NH_(4)^(+)),用比值分析法和相关性分析法分析其污染特征,结合地理统计分析和正定矩阵模型判断其主要来源.结果表明,Ca^(2+)、SO_(4)^(2−)、NO_(3)^(−)、Cl^(−)、K^(+)在安阳市道路积尘水溶性离子中占比较大,其中Ca^(2+)占比最高,SO_(4)^(2−)和NO_(3)^(−)次之.在3种道路类型中,Ca^(2+)在快速路、主干道和次干道的占比分别为53.0%、45.3%和45.9%;SO_(4)^(2−)在快速路、主干道和次干道的占比分别为16.7%、17.5%和18.5%.NO_(3)^(−)/SO_(4)^(2−)的比值为0.79,说明固定源的贡献更大;水溶性阴阳离子相关性斜率(0.42)小于1,道路积尘呈碱性.安阳市道路积尘中Ca^(2+)与SO_(4)^(2−),Na^(+)与Mg^(2+)和Cl^(−)空间分布相似,其高值区主要集中在研究区域的西北部和西南部.安阳市夏季道路积尘中水溶性离子的主要来源为机动车尾气源、燃煤源、农业源、混合源、扬尘源和生物质燃烧源,其贡献率分别为12.8%、19.1%、16.6%、14.7%和19.0%.以期为安阳市探究道路积尘污染源头和治理措施提出提供数据支持.

To understand the pollution characteristics and sources of water-soluble ions in road dust in Anyang City during summer,70 road dust samples were collected by a hand-held portable vacuum cleaner in May 2020 in this study,and 10 water-soluble ions(F^(−)、Cl^(−)、NO_(2)^(−)、NO_(3)^(−)、SO_(4)^(2−)、K^(+)、Na^(+)、Ca^(2+)、Mg^(2+)、NH_(4)^(+))were measured by ion chromatography.Ratio analysis and correlation analysis were used to analyze the pollution characteristics,and geographical statistical analysis and positive matrix factorization model were used to determine the main sources of water-soluble ions.The results showed that Ca^(2+)、SO_(4)^(2−)、NO_(3)^(−)、Cl^(−)、K^(+)accounted for a large proportion of watersoluble ions in road dust from Anyang City,and Ca^(2+)accounted for the highest proportion,followed by SO_(4)^(2−)and NO_(3)^(−).Among the three types of roads,Ca^(2+)accounts for 53.0%,45.3%and 45.9%of expressways,main roads and secondary roads respectively.SO_(4)^(2−)accounted for 16.7%,17.5%and 18.5%of expressways,main roads and secondary roads,respectively.The ratio of NO_(3)^(−)/SO_(4)^(2−)was 0.79,which showed that the contribution of stationary sources was greater than mobile exhaust.The correlation slope of water-soluble anion and anion(0.42)is less than 1,indicating that road dust was alkaline.The spatial distribution of Ca^(2+)and SO_(4)^(2−),Na^(+)and Mg^(2+)and Na^(+)and Cl^(−)in road dust of Anyang City were similar,and the high-value areas were mainly concentrated in the northwest and southwest of the study area.The main sources of water-soluble ions in road dust in Anyang City were vehicle exhaust sources,coal sources,agricultural sources,mixed sources,dust sources and biomass combustion sources,and their contribution rates were 12.8%,19.1%、16.6%,14.7%and 19.0%,respectively.To provide data support for Anyang city to explore the source of road dust and put forward control measures.