PM10 was measured from August to September 2010 in a suburb of Hefei, and the water-soluble ions such as NO2, Cl-, NO3- ,SO4 2-,NH4+,Ca2+ ,Na+ ,Mg2+ ,K+ in PM10 were analyzed. The results showed that the average PM10 concentration in summer was 78. 9 μg/m3. The mean concentration of the nine ions was 18. 93 μg/m3, comprising 26. 6% of the PM10. S04 2- , NO3-, NH4+ and Ca2+ were the major water-soluble ions,with concentrations of 8. 14,4. 81 ,3. 46 and 1. 33 μg/m, respectively. The relationship between PM10 and visibility was found to vary with the relative humidity. They were linearly correlated (R = -0.80) when RH was less than 80% ,and exponentially correlated (R = -0.48) when RH was larger than 80% . The correlation among the ions showed that the water-soluble ions mainly existed in the forms of ( NH4 )2SO4, NH4HSO4, NH4NO3, KCl and K2SO4. The ratio between NO3- and SO4 2-(0.59) suggested that the contribution of sulfur-rich point sources was larger than that of mobile source emissions on the ion concentrations in PM10. Additionally,dust was another important source of PM10.%2010年8-9月在合肥市郊对p(PM10)进行了观测,并分析了其中9种水溶性离子(N02 -、Cl-、N03 -、S042 -、NH4 -、Ca2、Na+、Mg2、K+)质量浓度.结果表明:采样期间该地区ρ( PM10)日均值为78.9 μg/m3,9种水溶性离子的平均质量浓度为18.93 μg/m3,占p( PM10)的26.6％,表明水溶性组分是PM10的重要组成之一.SO42-、NO3-、NH4+和Ca2是主要的阴、阳离子,日均质量浓度分别为8.14、4.81、3.46和1.33μg/m3.不同RH(相对湿度)下PM10对能见度的影响不同,RH小于80％时,二者呈显著的线性负相关[R(相关系数)为-0.80]；RH大于80％时,二者呈指数负相关(R为-0.48).离子间相关性分析显示,PM10中水溶性离子的主要结合方式为(NH4)2S04、NH4HSO4、NH4N03、KC1及K2SO4.采样期间ρ(N03 -)／ρ(S042-)平均值为0.59,说明在该地区固定源对水溶性组分的贡献大于移动源.另外,扬尘也是PM10重要来源之一.
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