| 硫酸铵和硝酸铵对镇江市大气PM2.5理化性质的影响 |
| 摘要点击 1544 全文点击 351 投稿时间：2022-10-24 修订日期：2022-12-06 |
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| 中文关键词 大气颗粒物 硫酸铵［(NH4)2SO4］ 硝酸铵 (NH4NO3) 消光系数 气溶胶液态水含量 气溶胶酸度 |
| 英文关键词 atmospheric particulate matter ammonium sulfate[(NH4)2SO4] ammonium nitrate (NH4NO3) extinction coefficient aerosol water content aerosol acidity |
| 作者 | 单位 | E-mail | | 曹军 | 江苏省环境监测中心, 南京 210019 | caoj@jshb.gov.cn | | 谢佳丽 | 北京化工大学软物质科学与工程高精尖创新中心, 气溶胶与霾实验室, 北京 100029 | | | 孙娟 | 江苏省南京环境监测中心, 南京 210019 | | | 李锦雯 | 北京化工大学软物质科学与工程高精尖创新中心, 气溶胶与霾实验室, 北京 100029 | | | 徐政 | 江苏省环境监测中心, 南京 210019 | | | 华陈杰 | 北京化工大学软物质科学与工程高精尖创新中心, 气溶胶与霾实验室, 北京 100029 | | | 张雨生 | 北京化工大学软物质科学与工程高精尖创新中心, 气溶胶与霾实验室, 北京 100029 | | | 宋柏颖 | 北京化工大学软物质科学与工程高精尖创新中心, 气溶胶与霾实验室, 北京 100029 | | | 刘永春 | 北京化工大学软物质科学与工程高精尖创新中心, 气溶胶与霾实验室, 北京 100029 | liuyc@buct.edu.cn |
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| 中文摘要 |
| 近年来，无机盐尤其是硝酸盐对我国大气PM2.5的贡献日益凸显，而其如何影响颗粒物的重要理化性质尚待深入研究.于2021年1~12月期间，在镇江市开展了连续观测，获得了大气PM2.5中硫酸铵［（NH4）2SO4）］和硝酸铵（NH4NO3）浓度，系统讨论了二者对颗粒物消光、吸湿增长和酸度的影响.结果表明，2021年镇江市ρ［（NH4）2SO4］和ρ（NH4NO3）的年均值分别为（6.5±4.5）μg ·m-3和（15.0±13.3）μg ·m-3，对PM2.5浓度的平均贡献率分别为（20.5±18.2）%和（34.5±18.4）%；PM2.5的总消光系数为（224.5±194.2） Mm-1，其中NH4NO3的贡献率为（40.1±20.9）%，（NH4）2SO4为（19.1±10.8）%；（NH4）2SO4和NH4NO3是PM2.5吸湿增长的主要贡献者，在污染条件下NH4NO3对颗粒物液态水的贡献率为（53.8±13.4）%~（61.6±14.6）%；NH4NO3是未来镇江市能见度和空气质量改善的关键污染物，但削减NH4NO3前体物可能会导致颗粒物酸度增加，尤其对春冬季节颗粒物酸度的影响较为明显.研究结果对理解空气质量变化及二次影响具有重要意义，并对镇江市空气质量的持续改善提供了重要参考. |
| 英文摘要 |
| Recently, the contribution of inorganic salts (nitrates in particular) to the mass concentration of particulate matter with an aerodynamic diameter of less than 2.5 μm (PM2.5) has been increasing across China. However, it is urgent to understand how the increased inorganic salts affect the crucial properties of PM2.5. Here, we conducted continuous field observations at Zhenjiang Ecology and Environment Protection Bureau from January 1 to December 31, 2021. The mass concentrations of ammonium sulfate[(NH4)2SO4] and ammonium nitrate (NH4NO3) were calculated using different methods. The contributions of (NH4)2SO4 and NH4NO3 to the extinction coefficient, hygroscopic growth, and acidity of PM2.5 were discussed in detail. Our results demonstrated that the mean mass concentrations of (NH4)2SO4 and NH4NO3 during the study period were (6.5±4.5) and (15.0±13.3) μg·m-3, which contributed (20.5±18.2)% and (34.5±18.4)% to the mass concentration of PM2.5, respectively. The total extinction coefficient of PM2.5 was (224.5±194.2) Mm-1, in which NH4NO3 was the largest contributor[(40.1±20.9)%] followed by (NH4)2SO4[(19.1±10.8)%]. (NH4)2SO4 and NH4NO3 were also the dominant contributors to the hygroscopic growth of PM2.5. In particular, NH4NO3contributed from (53.8±13.4)% to (61.6±14.6)% to the aerosol water content of PM2.5 under pollution conditions. Thus, NH4NO3 was a key air pollutant to be targeted for further improving the visibility and air quality in Zhenjiang in the future. However, the reduction in the precursors of NH4NO3 would lead to an increase in aerosol acidity, particularly in the spring and winter seasons. Our results help us understand the evolution of air quality and the related impacts and also provide important information on air quality improvement in Zhenjiang in the future. |
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