萍乡市春节前后气溶胶水化学及硫酸盐硫氧同位素特征

Chemical Characterization and Sulfur and Oxygen Isotope of Sulfate of Aerosol from New Year′s Day to Chinese Spring Festival

随着人为释放的污染物大量增加,诸如灰霾等大气污染事件经常在中国发生并变成中国城市中一个严重的大气环境问题。烟花燃放也是高强度的人为活动,会造成明显的空气污染和短期空气质量的下降。为了解释大气污染不同的形成原因,本研究于2017年1月1日至2月17日在萍乡采集了PM_(2.5)和PM_(10)气溶胶样品,分析其水溶性组分和SO_(4)^(2-)的硫氧同位素。结果表明,采样期萍乡市PM_(2.5)和PM_(10)浓度平均值分别为82μg/m^(3)和113μg/m^(3)。采样期主要出现两个高污染时间段,分别为2017年1月1日至6日(元旦大气污染事件)和2017年1月26日至2月3日(春节大气污染事件)。元旦大气污染事件中,PM_(2.5)和PM_(10)浓度平均值分别为175μg/m^(3)和274μg/m^(3);春节大气污染事件中,PM_(2.5)和PM_(10)浓度平均值分别为103μg/m^(3)和131μg/m^(3)。元旦大气污染事件主要由二次污染引起,而春节大气污染事件由烟花燃放引起。同位素结果显示,萍乡大气气溶胶中SO_(4)^(2-)主要来源于煤燃烧,且主要由H_(2)O_(2)非均相氧化形成。

Air pollution,such as haze,often occurs and has become a serious problem in Chinese urban cities with the large increase in anthropogenic emissions.Fireworks displays are high intensity anthropogenic activities that create notable air pollution and obvious short term air quality degradation.In order to understand the impact of fireworks displays on air quality,water soluble components of PM_(2.5)and PM_(10) on filter were determined off line,and sulfur and oxygen isotope compositions(δ^(34)S andδ^(18)O)of water-soluble SO_(4)^(2-)of PM_(2.5)and PM_(10)were also measured off line from January 1 to February 17,2017 in a serious polluted city,Pingxiang.The average concentrations of PM_(2.5)and PM_(10) were 82μg/m^(3)and 113μg/m 3 throughout the whole sampling period,respectively,while they were 175μg/m^(3)and 274μg/m^(3)during New Year(January 1 to 6,2017),respectively,and 103μg/m^(3)and 131μg/m^(3)during Chinses Spring Festival holiday(January 26 to February 3,2017),respectively.The air pollution was caused by secondary pollution during New Year and by heavy fireworks during Chinses Spring Festival holiday.Sulfur and oxygen isotope indicated that SO_(4)^(2-)was major from coal combustion and formed by heterogeneous oxidation via H_(2)O_(2).