Beijing Engineering Research Center of Radiographic Techniques and Equipment, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China; School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China.
Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan.
Chemosphere. 2018 Apr;196:393-401. doi: 10.1016/j.chemosphere.2017.12.126. Epub 2017 Dec 22.
An understanding of the species of chlorine is crucial in the metropolis-Beijing, which is suffering serious haze pollution with high frequency. Particulate Matters (PMs) with five different sizes were collected in Beijing from July 2009 to March 2016, and characterized non-destructively by X-ray absorption near edge structure spectroscopy. PM, PM and PM contributed for the major PMs mass in spring and summer, PM and PM contributed for the major PMs mass in autumn and winter. The concentrations of the three chlorine species were in the order of inorganic chlorine (Cl) > aliphatic chlorine (Cl) > aromatic chlorine (Cl), indicating that Cl constituted the primary chlorine fraction and less toxic Cl constituted the primary total organic chlorine (Cl + Cl, abbreviated as Cl) in the PMs in Beijing. In addition, these three chlorine species exhibited identical seasonal variation in PM: winter > autumn > spring > summer. Wet precipitation is an important factor to result in the lower mass concentrations of these three chlorine species in summer. The temporal variations of both size resolved PM mass concentrations and chlorine species concentrations suggested that the air pollution prevention and control in Beijing has just won initial success.
了解氯的各种形态对于饱受高频重度雾霾污染之苦的特大城市-北京来说至关重要。本研究于 2009 年 7 月至 2016 年 3 月期间在北京市采集了五种不同粒径的颗粒物（PM），并采用 X 射线吸收近边结构光谱法对其进行了无损特征分析。春夏季，PM、PM 和 PM 对 PM 质量浓度的贡献较大；秋冬季，PM 和 PM 对 PM 质量浓度的贡献较大。三种氯形态的浓度顺序为无机氯（Cl）＞脂肪族氯（Cl）＞芳香族氯（Cl），表明 Cl 构成了 PM 中主要的氯成分，毒性较小的 Cl 构成了 PM 中主要的总有机氯（Cl + Cl，简称 Cl）。此外，这三种氯形态在 PM 中具有相同的季节性变化规律：冬季＞秋季＞春季＞夏季。夏季湿沉降是导致这三种氯形态质量浓度降低的重要因素。PM 粒径分布和氯形态浓度的时间变化表明，北京市的空气污染防治工作才刚刚取得初步成效。
