北方某工业城市大气PM_(2.5)成分及来源分析

Analysis of Atmospheric PM_(2.5) Composition and Source in an Industrial City in Northern China

为了解北方某工业城市大气PM_(2.5)中无机元素与有机物时间分布特征,并分析可能的来源,2019年12月至2020年11月采集该市大气PM_(2.5),运用ICP-MS法测定PM_(2.5)中无机元素及稀土元素的含量,运用HPLC法测定PM_(2.5)中多环芳烃(PAHs)的含量,并采用富集因子法及特征比值法进行来源分析。在采样期间大气PM_(2.5)年平均浓度为82.76μg/m^(3),冬季大气PM_(2.5)浓度最高(128.65μg/m^(3)),夏季大气PM_(2.5)浓度最低(57.62μg/m^(3));春季PM_(2.5)中11种无机元素浓度最高,不同季节大气PM_(2.5)中Be、V、Mn、Se、Sn、Tl平均浓度差异有统计学意义(P<0.05);春季大气PM_(2.5)中14种稀土元素含量最高,不同季节大气PM_(2.5)中14种稀土元素含量无统计学意义(P>0.05);冬季大气PM_(2.5)中15种PAHs含量较高,不同季节PM_(2.5)中有14种PAHs差异均有统计学意义(P<0.05);春季、夏季中稀土元素与无机元素为正相关(P<0.05),春季、冬季中稀土元素与有机物为负相关(P<0.05);源分析结果表明,该市PM_(2.5)中无机元素、稀土元素、PAHs受到人为污染源的影响明显。该市大气PM_(2.5)污染较为严重,无机元素、稀土元素、PAHs在不同季节含量差异较大,大气PM_(2.5)中无机元素、稀土元素、PAHs主要来源于燃煤及工业污染源。

To understand the time distribution characteristics of inorganic elements and organic matter in atmospheric PM_(2.5) in an industrial city in northern China and analyze possible sources to provide a basis for the prevention and control of urban air pollution, atmospheric PM_(2.5) was collected in November 2020 to determine inorganic elements and rare earth elements in PM_(2.5) by ICP-MS method, PAHs aromatic hydrocarbon(PAHs) in PM_(2.5) by HPLC method, and source analysis by enrichment factor method and characteristic ratio method. The mean annual concentration of atmospheric PM_(2.5) in the city during the sampling period was 82.76 μg/m^(3). It exceeds the average annual PM_(2.5) concentration limit(35 μg/m^(3)) in the Ambient Air Quality Standard. The concentration of atmospheric PM_(2.5) is the highest(128.65 μm/m^(3)) in winter and the lowest(57.62 μm/m^(3)) in summer. The concentration of 11 inorganic elements in PM_(2.5) is the highest in spring, and the average concentration of Be, V, Mn, Se, Sn and Ti in atmospheric PM_(2.5) in different seasons has statistically significant difference(P<0.05);The contents of 14 rare earth elements in atmospheric PM_(2.5) in spring are the highest, and the contents of 14 rare earth elements in atmospheric PM_(2.5) in different seasons are not statistically significant(P>0.05);The content of 15 PAHs in atmospheric PM_(2.5 )in winter is relatively high, and there are statistically significant differences in 14 PAHs in PM_(2.5) in different seasons(P<0.05) and positively correlated with inorganic elements in spring and summer(P<0.05), Rare earth elements are negatively correlated with organic matter in spring and winter(P<0.05);The results show that inorganic elements, rare earth elements and PAHs in the city PM_(2.5) are significantly affected by artificial pollution sources. Air PM_(2.5) pollution in the city is serious;The content of inorganic elements, rare earth elements and PAHs varies greatly in different seasons;the inorganic elements, rare earth elements and PAHs in atmospheric PM_(2.5) in the city are mainly derived from coal burning and industrial pollution sources.