内河船舶排放PM_(2.5)源成分谱特征研究

Characteristics of source profile of PM_(2.5) emissions from inland ships

内河船舶排放的细颗粒物(PM_(2.5))源成分谱研究十分匮乏.本研究以长江武汉段船舶为研究对象,构建了内河船舶排放PM_(2.5)的源成分谱,研究了高速、中速、低速3种不同工况下船舶排放PM_(2.5)的源成分谱特征,并对船舶排放PM_(2.5)中重金属的健康风险进行了评价.结果表明:内河船舶排放的PM_(2.5)主要组分为碳质组分(w≥10%),其次是水溶性离子(w≤8%)和元素组分(w≤3%);不同工况下船舶排放PM_(2.5)中有机碳、元素碳、硝酸盐的占比随转速的增加而增大,而其他水溶性离子和各元素的质量百分比则呈现相反的规律;同类型船舶排放的PM_(2.5)源成分谱基本相似,不同类型船舶的PM_(2.5)源成分谱差异性较大;船舶排放PM_(2.5)中的重金属具有一定的非致癌风险和致癌风险,其中,重金属Cr、Cd和V存在非癌症风险;重金属Cr、Cd则具有高癌症风险.

The research on the source profile of PM_(2.5) emissions from inland ships are scarce.In this study,we constructed source profiles of PM_(2.5)emissions from inland ships in Wuhan section of the Yangtze River.We explored PM_(2.5) emissions under three different operating conditions:high speed,medium speed,and low speed.Besides,we evaluated the health risks of heavy metals in the emitted PM_(2.5).The results showed that the main components of PM_(2.5) emitted by inland ships are carbonaceous components(w≥10%),followed by water-soluble ions(w≤8%) and elemental components(w≤3%).The proportion of organic carbon,elemental carbon,and NO3-in PM_(2.5) increases with the increase of rotational speed,while the proportion of other water-soluble ions and the elements exhibit opposite trends.The source profiles of PM_(2.5) emissions from the same type of ships are basically similar,while those from different types of ships are significantly different.Heavy metals emitted from ships are of both high non-cancer risk and high cancer risk.Among which,Cr,Cd,and V contribute to non-cancer risks,while heavy metals Cr,Cd contribute to cancer risks.