上海重霾期间SNA分布特征
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- 英文论文题名：Size distribution of SNA during Haze Period in Shanghai
- 论文作者：陶冶 ; 谢愿愿 ; 王儒宇 ; 叶兴南
- 英文论文作者：Ye Tao ; Yuanyuan Xie ; Ruyu Wang ; Xingnan Ye ; Department of Environmental Science & engineering ; Fudan University
- 年：2016
- 作者机构：复旦大学环境科学与工程系;
- 论文关键词：霾 ; 硝酸盐 ; 形成机制
- 英文论文关键词：Haze ; Nitrate ; formation mechanisms
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第二十六分会：环境化学
- 语种：中文
- 分类号：X513
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第二十六分会 ; 环境化学
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：270k
- 原文格式：D
- 会议级别：全国
摘要
在2014年12月-2015年1月,在上海开展了为期70天的冬季观测。观测期间共发生11次中度及重度污染过程,首要污染物都是大气细颗粒物。从中和比NR上看,在细颗粒上铵根完全中和硫酸盐与硝酸盐,说明硫酸盐与硝酸盐的主要存在形式为(NH4)2SO4和NH4NO3。而在粗颗粒上铵钙组合才能中和硫酸盐与硝酸盐,这与扬尘污染较大有关。Cl/Na比为2.27,高于海盐的理论值(1.8),说明来自内地的外源性输入的贡献。霾天PM1.8硝酸盐增加了75%、铵盐增加了62%、硫酸盐增加了52%,其中以硝酸盐的增加最为显著,说明霾天的气象条件和大气环境最有利于NOx的氧化和气-固转化。从图1中可以看出,随着硝酸盐浓度的增高,平均粒径向1微米左右的粒径集中,而硝酸盐的浓度达到峰值时期对应的粒径大约为1.2μm。这说明二次污染物在已有颗粒上凝结,引起颗粒物粒径增长,是污染形成的主导机制。本研究说明,消减NOx应成为冬季灰霾防治的重中之重。另一方面,上海的大气污染受周边省份影响比较大,冬季的灰霾治理必须走区域联防联治的道路。
A field campaign with more was deployed during the period of Dec2014 to Jan 2015.Eleven hazes events was observed with the fine particulates as primary pollutant.According to the neutralization ratio,ammonium can balance all fine particulate sulfate and nitrate,indicating that their major existing forms of(NH4)2SO4和 NH4NO3.In contrast,the coarse mode sulfate and nitrate were balanced by ammonium and calcium because of a considerable contribution of soil dust.The mean mass ratio of Cl/Na was 2.27,higher than that of sea salt(1.8),indicating the contribution of inland transport.Compared with clear days,the concentrations of nitrate,ammonium,and sulfate during haze periods increased by 75%,62%,and 52%,respectively.This finding showed that the gas to particle conversion for NOx was favored under haze conditions.As shown in Fig.1,nitrate mass loading in PM18 first increased and then decreased with the mode diameter of nitrate,peaking at the mode diameter of 1.2 ?m.This finding revealed that the condensation of secondary aerosols on preexisting particles caused significant particle growth,which was the dominant formation mechanism of haze.This study suggests that the reduction of NOx emissions should be regarded as a priority task for the air quality control in winter.In the other hand,collaboration among YRD cities is crucial against haze challenges because of significant contribution of long range transport of atmospheric pollutants.
A field campaign with more was deployed during the period of Dec2014 to Jan 2015.Eleven hazes events was observed with the fine particulates as primary pollutant.According to the neutralization ratio,ammonium can balance all fine particulate sulfate and nitrate,indicating that their major existing forms of(NH4)2SO4和 NH4NO3.In contrast,the coarse mode sulfate and nitrate were balanced by ammonium and calcium because of a considerable contribution of soil dust.The mean mass ratio of Cl/Na was 2.27,higher than that of sea salt(1.8),indicating the contribution of inland transport.Compared with clear days,the concentrations of nitrate,ammonium,and sulfate during haze periods increased by 75%,62%,and 52%,respectively.This finding showed that the gas to particle conversion for NOx was favored under haze conditions.As shown in Fig.1,nitrate mass loading in PM18 first increased and then decreased with the mode diameter of nitrate,peaking at the mode diameter of 1.2 ?m.This finding revealed that the condensation of secondary aerosols on preexisting particles caused significant particle growth,which was the dominant formation mechanism of haze.This study suggests that the reduction of NOx emissions should be regarded as a priority task for the air quality control in winter.In the other hand,collaboration among YRD cities is crucial against haze challenges because of significant contribution of long range transport of atmospheric pollutants.
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