【摘要】 选择昌九高速公路(赣粤高速公路南昌至九江段)、昌樟高速公路(赣粤高速公路南昌至樟树段)为研究对象,采集了公路两侧10μm<Da50≤100μm的颗粒和PM10,测定了其中锌、铅、锰、铜、镉、锑的浓度,研究了高速公路两侧大气颗粒物中锌、铅、锰、铜、镉、锑污染状况和分布规律,并探讨了车流量、颗粒物粒径、天气及距公路距离等因素对重金属分布的影响.研究结果显示,大气颗粒物中重金属浓度从高到低依次是锌、铅、锰、铜、镉和锑.锌、铅、锰、铜、镉、锑的浓度随着车流量增加而增加,说明交通活动是这几种金属的一个主要来源.锌和锰在小于10μm和大于10μm的颗粒物中浓度都较高,这可能是因为以PM10形式存在的锌和锰来源于汽车尾气,以大于10μm形式存在的锌和锰主要来源于汽车磨损,汽车尾气释放和汽车磨损释放对锌和锰的贡献都较大.锑主要以PM10存在,而与锑具有共同来源(制动块磨损)的铜在小于10μm和大于10μm的颗粒物中浓度都较高,证明铜除了来源于制动块磨损,可能还有其它来源.铅和镉在高速公路两侧大气中很明显主要以PM10存在.天气主要对公路两侧大气颗粒物中锌含量影响较大,对其它金属含量影响不大.距离高速公路10 m以内,各重金属浓度下降趋势不明显,主要是因为重金属主要以PM10存在,迁移能力较强.铅、锑在乡村与在公路两侧大气中相比,浓度明显下降,这可能是因为铅、锑主要来源是交通源.更多还原

【Abstract】 Metal concentrations were measured in different size airborne particles collected near two expressways with different traffic densities from April 2009 to June 2009.The pollution characterization and distribution mode of Zn,Pb,Mn,Cu,Cd,Sb in airborne particles were studied to discuss the influence of traffic volume,particle size,weather and distance.The results show that Zn concentration in airborne particles was the highest,followed by Pb,Mn,Cu,Cd,and Sb concentration was the lowest.The metal concentration was highly dependent on traffic volume,indicating that traffic was the main source of these metals.The high concentrations of Zn and Mn in PM10(possibly originated from gas exhaust) and 10 μm<Da50≤100 μm particles(possibly associated with tire wear) suggest that gas exhaust and tire wear were the main sources of Zn and Mn.Antimony(Sb) existed mostly in PM10 and originated mainly from the wear of brake linings.The concentration of Cu was high in both PM10 and 10 μm<Da50≤100 μm particles,suggesting that Cu had other sources than the wear of brake linings.Lead(Pb) and Cd existed mainly in PM10.Weather mainly influenced the Zn concentration,but not other metals.Within 10 meters from the expressway,the metal concentration decreased little.The concentrations of Pb,Sb in the countryside was noticeably lower as compared with their concentrations near the expressway,which may be explained by the fact that the main source of airborne Pb,Sb was traffic.更多还原