典型港口城市船舶排放细颗粒物理化特征及其大气老化过程研究

Shipping emission is regarded as an important source for atmospheric pollutants in port city. It not only caused primary pollution, and it would contribute to a secondary pollution during aging process and transport in the atmosphere. At present, the research on ship emissions is weak in China. Especially, studies on physic-chemical characterization and aging process of shipping emitted particles and their impact on air quality of domestic port cities are few. We intend to take Guangzhou as a typical port city in south China. Online instruments such as SPAMS and SMPS with high time resolution are applied in this study to investigate physic-chemical characterization and aging process of the fine particles from shipping emission. An accurate screening method for shipping emitted fine particles are established based on particulate size distribution, mass spectrometry, characteristic species and relative abundances. Field observations are carried out synchronously in port and urban areas of Guangzhou to evaluate the impact of atmospheric oxidability and particulate acidity on the aging of shipping emitted particles as well as how the secondary formation of aerosols are promoted in this aging process. Shipping emitted particles’ contributions to the atmospheric fine particles in port and urban areas in different seasons and under different meteorological conditions are estimated, respectively. Results and findings of this study are expected to provide solid scientific proof to parameterization of shipping emission modeling and emission contribution estimate in a typical domestic port city as well as to benefit the policy making on port pollution control and urban air quality improvement.

船舶排放是港口城市的重要排放源，不仅构成一次污染，在传输和老化过程中对于城市二次污染也具有重要影响。目前国内对于船舶排放的研究较为薄弱，尤其对于船舶排放细颗粒物的理化特征、老化过程及其对港口城市影响的系统研究存在不足。本项目拟以广州市船舶排放细颗粒物为研究对象，首先利用单颗粒气溶胶质谱仪、粒径谱仪等设备对船舶排放源直接采样，综合分析船舶排放细颗粒物的粒径分布、质谱特征、混合状态、特征物种及相对丰度等信息，建立船舶排放细颗粒物的筛选方法；进而在港区和市区开展同步的外场观测，研究大气氧化性、颗粒物酸度对船舶排放细颗粒物老化过程的影响，以及船舶排放细颗粒物对二次气溶胶转化的促进作用；最后估算在不同季节和气象条件下船舶排放细颗粒物对港区和市区大气细颗粒物的贡献。本项目将对典型港口城市船舶排放颗粒物模型参数化和排放贡献估算提供可靠的科学依据，对控制港口城市大气污染排放和治理提供重要参考。

船舶排放是港口城市的重要排放源，不仅构成一次污染，在传输和老化过程中对于城市二次污染也具有重要影响。目前国内对于船舶排放的研究较为薄弱，尤其对于船舶排放细颗粒物的理化特征、老化过程及其对港口城市影响的系统研究存在不足。本项目以广州、上海、唐山三个港口城市为典型城市，开展船舶排放尾气对港口城市空气质量影响的研究。以广州南沙、唐山京唐港区船舶排放细颗粒物为研究对象，利用单颗粒气溶胶质谱仪等设备对船舶排放源直接采样，综合分析船舶排放细颗粒物的粒径分布、质谱特征、混合状态、特征物种及相对丰度等信息。确定了燃油转换后，钒和镍不再适合作为船舶排放颗粒物的示踪物，建立了船舶排放细颗粒物的筛选方法；对广州港区排放控制区政策实施前后船舶辅机大气污染物排放特征及排放因子开展了研究；在上海、京唐港区开展了外场观测，研究了船舶排放对大气空气质量的影响；在广州、上海港区和市区同步开展了和市区都开展同步的外场观测，研究了大气颗粒物的老化情况，颗粒物相对酸度等。研究了在不同季节和气象条件下船舶排放细颗粒物对港区和市区大气细颗粒物的贡献。项目成果可对典型港口城市船舶排放颗粒物模型参数化和排放贡献估算提供可靠的科学依据，对控制港口城市大气污染排放和治理提供重要参考。