Chemical characteristics of fine particles and their impact on visibility impairment in Shanghai based on a 1-year period observation

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• 作者：Min Zhou¹ ; ² ; ^{zhoum@saes.sh.cn" class="auth_mail" title="E-mail the corresponding author} ; Liping Qiao¹ ; ² ; Shuhui Zhu¹ ; ² ; Li Li¹ ; ² ; ^{lili@saes.sh.cn" class="auth_mail" title="E-mail the corresponding author} ; Shengrong Lou¹ ; ² ; Hongli Wang¹ ; ² ; Qian Wang¹ ; ² ; Shikang Tao¹ ; ² ; Cheng Huang¹ ; ² ; Changhong Chen¹ ; ²
• 关键词：PM2.5 ; Chemical composition ; Light extinction efficient ; Shanghai
• 刊名：Journal of Environmental Sciences
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：48
• 期：Complete
• 页码：151-160
• 全文大小：864 K

文摘

In this work, a one-year observation focusing on high time resolution characteristics of components in fine particles was conducted at an urban site in Shanghai. Contributions of different components on visibility impairment were also studied. Our research indicates that the major components of PM_2.5 in Shanghai are water-soluble inorganic ions and carbonaceous aerosol, accounting for about 60% and 30% respectively. Higher concentrations of sulfate (SO₄²⁻) and organic carbon (OC) in PM_2.5 occurred in fall and summer, while higher concentrations of nitrate (NO₃⁻) were observed in winter and spring. The mass concentrations of Cl⁻ and K⁺ were higher in winter. Moreover, NO₃⁻ increased significantly during PM_2.5 pollution episodes. The high values observed for the sulfate oxidizing rate (SOR), nitrate oxidizing rate (NOR) and secondary organic carbon (SOC) in OC indicate that photochemical reactions were quite active in Shanghai. The IMPROVE (Interagency Monitoring of Protected Visual Environments) formula was used in this study to investigate the contributions of individual PM_2.5 chemical components to the light extinction efficient in Shanghai. Both NH₄NO₃ and (NH₄)₂SO₄ had close relationships with visibility impairment in Shanghai. Our results show that the reduction of anthropogenic SO₂, NO_x and NH₃ would have a significant effect on the improvement of air quality and visibility in Shanghai.