摘要
2013年7月至2014年4月期间,在银川市兴庆区设1个环境监测点,分4季采集PM_(10)和PM_(2.5) 样品,测试二者质量浓度及水溶性阴离子(Cl^-、NO_3^-、SO_4^(2-))、阳离子(K^+、Na^+、Ca^(2+)、Mg^(2+)、NH_4^+)成分,分析其主要组成、季节变化及污染来源。结果表明:银川市PM_(10)和PM_(2.5) 中离子平均浓度为33.8、18.74μg/m3,分别占PM_(10)和PM_(2.5) 的17.2%、23.5%。NH_4^+、Cl^-、NO_3^-和SO_4^(2-)等二次离子含量高,分别占离子总量的75%和84%,且冬季含量是其他季节的数倍;颗粒物总体呈碱性,PM_(10)中阳离子总量与阴离子总量的比值为1.23,PM_(2.5) 中两者比值为1.14,PM_(10)比PM_(2.5) 碱性强;大气中存在SO_2向SO_4^(2-)二次转化过程。冬季PM_(2.5) 中二次离子主要以(NH4)_2SO_4和NH_4NO_3形式存在;来源分析发现,PM_(2.5) 、PM_(10)可能主要来源于生物质燃烧、二次反应及燃煤尘。
A monitoring point was set up in Xingqing District of Yinchuan City to collect PM10 and PM_（2.5） samples of each season to analyze its main composition, seasonal variation and pollution sources by testing its mass concentration and water soluble anion（Cl^-, NO_3^-and SO_4^（2-）） and cation（K＋, Na＋, Ca2＋, Mg2＋and NH_4~＋） composition. Results showed that the average ion concentration of PM10 ion and PM_（2.5） were 33.8 μg/m3 and 18.74 μg/m3 respectively, taking up 17.2% and 23.5% of total PM10 and PM_（2.5） content. NH_4~＋, Secondary ions content in Cl^-, NO_3^-, and SO_4^（2-）were high, accounting for 75% and 84%of the total PM10 and PM_（2.5） content and were several times of that in winter. The particles were alkaline. The ratio of anion content and cation content was 1.23 in PM10 and 1.14 in PM_（2.5） , indicating alkaline in PM10 was higher than that in PM_（2.5） .Secondary transformation from SO_2 to SO_4^（2-）was shown in the atmosphere.（NH4）_2SO_4、NH_4NO_3were the main forms of secondary ions in PM_（2.5） in winter. It was concluded that the main sources of PM10 and PM_（2.5） were biomass combustion, secondary reaction and coal combustion.
出处
《宁夏农林科技》
2017年第6期59-62,共4页
Journal of Ningxia Agriculture and Forestry Science and Technology
