青岛不同强度霾天气溶胶中二次无机离子的生成及粒径分布

发布时间：2018-04-11 18:31

本文选题：霾天 + 气溶胶　；参考：《环境科学》2017年07期

【摘要】：于2015年9月至2016年2月在青岛近海连续收集了大气气溶胶分级样品,用离子色谱法分析了其中的水溶性无机离子组分,并讨论了不同强度霾天下气溶胶中二次无机组分的粒径分布,初步探索了霾天SNA的形成过程和影响因素.结果表明,气溶胶中NO_3~-、SO_4~(2-)、NH_4~+、NO_2~-和Cl~-的质量浓度变化范围分别是10.32~193.46、4.42~74.05、2.21~57.75、0.05~2.22和1.35~17.39μg·m~(-3),且SNA的质量浓度随霾污染程度的加剧明显增加.与非霾天相比,轻微、轻度、中度和重度霾天与非霾天相比,NO_3~-的质量浓度分别增加了55%、77%、240%和537%;SO_4~(2-)的质量浓度分别增加了4.7%、35%、77%和262%;NH_4~+的质量浓度分别增加了72%、83%、201%和526%.细粒径上的NO_3~-、SO_4~(2-)与其气态前体物NO_2、SO_2均有显著相关性,且与相对湿度、能见度、风速等气象条件相关性较好,说明细粒径SNA的生成是造成霾天能见度下降,形成空气污染的主要原因之一,同时,高浓度前体物、较大相对湿度、低风速都是影响霾天形成的重要因素.除轻微霾天外,其他不同强度霾天的SOR(硫氧化率)、NOR(氮氧化率)均大于非霾天,且随着霾程度的加剧,SOR、NOR都有明显的升高,尤其是0.43~0.65μm和0.65~1.1μm粒径段;在重度霾天,氮和硫的转化率平均为非霾天的1.5倍,说明细粒径上的硫酸盐和硝酸盐大部分是气-粒转化而来.NO_3~-、NH_4~+、NO_2~-和SO_4~(2-)主要存在于细粒径段,霾天下在细粒径上的比例都显著增大,NO_3~-和SO_4~(2-)在严重霾天所占比例最高,分别达到79.4%和74.4%.NO_3~-在非霾、轻微、轻度霾天时均呈双峰分布,峰值出现在0.43~0.65μm和3.3~4.7μm处,中度霾天时细粒子峰值移动到0.65~1.1μm,在重度霾天粒径分布变为0.65~1.1μm的单峰分布.SO_4~(2-)只在非霾条件下呈双峰分布,峰值出现在0.43~0.65μm和2.1~3.3μm粒径段,霾天下均是单峰分布,轻微和轻度霾天下峰值出现在0.43~0.65μm,中度和重度霾天下峰值在0.65~1.1μm处.NH_4~+呈单峰分布,在非霾和轻微霾天下峰值出现在0.43~0.65μm粒径段,轻度、中度和重度霾天下峰值均出现在0.65~1.1μm粒径段.
[Abstract]:Atmospheric aerosol fractionation samples were collected from September 2015 to February 2016 in the coastal waters of Qingdao, and the water soluble inorganic ion components were analyzed by ion chromatography.The particle size distribution of secondary inorganic components in aerosols with different haze intensities was discussed, and the formation process and influencing factors of SNA in haze days were preliminarily explored.There is a significant correlation between no _ 3O _ 3 / so _ 4 and no _ 2O _ 2s _ 2, and a good correlation with meteorological conditions such as relative humidity, visibility, wind speed and so on, indicating that the formation of fine-grained SNA is the cause of reduced visibility in haze days.At the same time, high concentration of precursors, high relative humidity and low wind speed are the important factors that affect the formation of haze.With the exception of mild haze days, the sulfur oxidation rate (SCR) in other haze days with different intensities was higher than that in non-haze days, and with the increase of haze degree, there was a significant increase in SORN nor, especially in the particle sizes of 0.43 ~ 0.65 渭 m and 0.65 ~ (1) 渭 m, and in severe haze,The average conversion rate of nitrogen and sulfur is 1.5 times that of non-haze days, indicating that most of the sulphate and nitrate in fine particle size are gas-particle transformation.The peak value of fine particles moved to 0.65 ~ 1.1 渭 m in moderate haze days, and changed to 0.65 ~ (1.1 渭 m) in severe haze days. The single peak distribution of particle size changed to 0.65 ~ (1) 渭 m. So _ (4) ~ (2) ~ (2)) in the condition of non-haze, the peak appeared in the particle size range of 0.430.65 渭 m and 2.1 ~ (3) 渭 m, and the distribution of haze was single peak.
【作者单位】：中国海洋大学海洋环境与生态教育部重点实验室;中国海洋大学环境科学与工程学院;
【基金】：国家重大科学研究计划项目(2014CB953701)
【分类号】：X513

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