北京市秋季亚微米细颗粒物浓度及其化学组分特征

 采用多通道采样器和气溶胶化学组成在线监测仪，对2016年10月北京市区大气亚微米颗粒物（PM₁）化学组分进行了离线采样和在线监测。结果表明，整个观测期间，北京PM₁质量浓度平均为66.04±51.45 μg/m³，重霾期间PM₁的质量浓度（103.16~160.23 μg/m³）是清洁天（3.50~3.78 μg/m³）的27.29~45.78倍；北京秋季重霾天和清洁天的化学组分存在显著差异，有机物是PM₁的主要化学组分，清洁天贡献高达64.90%；而在重霾天，二次无机组分显著增长，贡献高达69.72%。硫酸盐日变化趋势相对平缓，反映出区域特性；而其他组分（有机物、硝酸盐、铵盐及氯化物）表现出显著的日变化特征。整体而言，大气PM₁中各组分受污染源排放、大气化学反应及天气形势的协同影响。

Study on the concentration of submicron fine particles and its chemical constituents in autumn in Beijing

In this paper, the URG's multi-channel sampler and the Aerosol Chemical Speciation Monitor (ACSM) are used for off-line sampling and online monitoring, focusing on the chemical components of atmospheric submicron particles (PM₁) in Beijing in October 2016. It is shown that the average concentration of PM₁ in Beijing during the whole observation periods is 66.04 ±51.45 μg/m³ and the mass concentration of PM₁ in heavy haze (103.16~160.23 μg/m³) is 27.29~45.78 times of that in clean days (3.50~3.78 μg/m³). Significant differences are observed of the chemical components between heavy haze days and clean days in autumn in Beijing. The organic materials are the main chemical components of PM₁, contributing up to 64.90% during the clean days. While the secondary inorganic components increase significantly, reaching as high as 69.72% during the heavy haze days. The diurnal variation of sulfate is relatively small, reflecting the regional characteristics; while other components (organic matter, nitrate, ammonium and chloride) see significant diurnal variations. Overally, the composition of PM₁ is affected by sources of pollution, atmospheric chemical reactions and the weather conditions.