泉州市大气PM_(2.5)镧系元素组成特征及来源解析

Composition Characteristics and Sources Apportionment of Lanthanoid in PM_(2.5) of Quanzhou

2014年3月、4月和7月分别采集了泉州市5个采样点共49个PM_(2.5)样品,采用电感耦合等离子体质谱(ICP-MS)测定样品镧系元素(Loid)及其他微量金属元素浓度水平.分析了PM_(2.5)镧系元素组成特征和配分模式,利用La-Ce-V三元图和化学质量平衡(CMB)受体模型解析了泉州市大气PM_(2.5)污染来源.结果表明:(1)泉州市大气PM_(2.5)总镧系元素(Σ Loid)浓度为2.490~5.708 ng·m^(-3)(含量65.682~126.529μg·g^(-1)),轻重镧系元素比值(L/H)为12.086~14.319;(2)PM_(2.5)镧系元素配分模式与福建土壤相似,PM_(2.5)中Ce元素表现为正异常,而Eu元素表现为负异常;(3)城市扬尘、燃煤尘、汽车尾气尘和垃圾焚烧飞灰是泉州市大气PM_(2.5)的主要来源,贡献率分别为18.9%、10.9%、30.6%和30.2%.

Samples of PM2.5 were collected from 5 sites in Quanzhou in March, April and July, 2014. The concentrations of lanthanoid and other trace metals in the PM2.5 were determined by Inductively Coupled Plasma Mass Spectrometry（ICP-MS）. The total lanthanoid concentration （ΣLoid）, the ratio of light-lanthanoid（L Loid, including, La, Ce, Pr, Nd, Sm and Eu） to heavy-lanthanoid（H Loid, including Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu） in PM2.5 were 2.490-5.708 ng·m-3（65.682-126.529 μg·g-1） and 12.086-14.319, respectively. The distribution pattern of Loid in PM2.5 was also evaluated in this study. All PM2.5 samples showed similar distribution pattern with local topsoil. And positive Ce and negative Eu anomalies were observed in PM2.5. La-Ce-V plots and chemical mass balance（CMB） model were used for source identification and apportionment of PM2.5in Quanzhou. The CMB model was used to identify four main sources：urban fugitive dust, coal combustion, vehicle exhaust and waste incineration emission which had a contribution of 18.9%, 10.9%, 30.6% and 30.2%, respectively.