| 伊犁河谷核心区春季PM2.5组分特征及来源解析 |
| 摘要点击 3381 全文点击 2530 投稿时间：2022-02-08 修订日期：2022-07-15 |
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| 中文关键词 无机元素 水溶性离子 碳组分 PM2.5 源解析 伊犁河谷 |
| 英文关键词 inorganic elements water-soluble ions carbon components PM2.5 source apportionment Ili River Valley |
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| 中文摘要 |
| 为研究伊犁河谷核心区春季大气细颗粒物（PM2.5）中无机元素、水溶性离子和碳组分特征和来源，于2021年4月20~29日在伊犁河谷核心区布设6个环境采样点，对PM2.5中水溶性离子、无机元素和碳组分等51种化学组分进行分析，并使用化学质量平衡（CMB）模型对其来源进行解析.结果表明，采样期间ρ（PM2.5）变化范围介于9~35 μg ·m-3.Si、Ca、Al、Na、Mg、Fe和K等地壳元素占比较高，占PM2.5的12%，表明春季PM2.5受到明显的扬尘源的影响.富集因子结果表明，Zn、Ni、Cr、Pb、Cu和As元素主要来源于化石燃料燃烧和机动车排放.元素组分的空间分布特征受采样点周边环境的影响，新政府片区受燃煤源的影响较大，故As浓度较高，伊宁市局和第二水厂受机动车影响较大，Sb和Sn浓度较高.PM2.5中9种水溶性离子（WSIIs）的浓度占PM2.5的33.2%，其中ρ（SO42-）、ρ（NO3-）、ρ（Ca2+）和ρ（NH4+）分别为（2.48±0.57）、（1.22±0.75）、（1.18±0.49）和（0.98±0.45）μg ·m-3，Ca2+高同样反映了扬尘源的影响.各采样点n（NO3-）/n（SO42-）介于0.63~0.85之间，说明伊犁河谷核心区受固定源影响高于移动源，伊宁市局和第二水厂临路受机动车排放尾气影响较大，导致其n（NO3-）/n（SO42-）较高，伊宁县位于居民区，受散煤燃烧影响较大，故n（NO3-）/n（SO42-）值较低.PM2.5中ρ［有机碳（OC）］和ρ［元素碳（EC）］平均值（范围）分别为5.12 μg ·m-3（4.67~6.25 μg ·m-3）和0.75 μg ·m-3（0.51~0.97 μg ·m-3），伊宁市局两侧临路受机动车尾气影响较大，故该站点OC和EC浓度略高于其他采样点.采用最小比值法计算得到的SOC （二次有机碳）结果显示，新政府片区、第二水厂和伊宁市局SOC浓度高于其他站点.CMB源解析结果显示该区域PM2.5主要贡献源为二次颗粒物（33.3%）和扬尘源（17.5%），且二次颗粒物以二次有机碳（16.2%）为主. |
| 英文摘要 |
| To explore the characteristics and sources of PM2.5 in the core area of Ili River Valley in spring, a total of 140 PM2.5 samples were collected at six sampling sites during April 20-29, 2021, and 51 chemical components including inorganic elements, water-soluble ions, and carbon components were analyzed. The results showed that ρ(PM2.5) was at a low level during sampling, ranging from 9 μg·m-3 to 35 μg·m-3. Si, Ca, Al, Na, Mg, Fe, and K were the most abundant elements, accounting for 12% of PM2.5, indicating that PM2.5 was affected by the dust sources in spring. The spatial distribution characteristics of elements depended on the surrounding environments of the sampling sites. The new government area was affected by coal-fired sources, so the value of As concentration was high. Yining Municipal Bureau and the Second Water Plant were greatly affected by motor vehicle sources, so the values of Sb and Sn concentration were higher. The enrichment factor results showed that Zn, Ni, Cr, Pb, Cu, and As were mainly emitted from fossil fuel combustion and motor vehicles. The concentration of water-soluble ions accounted for 33.2% of PM2.5. Among them, ρ(SO42-), ρ(NO3-), ρ(Ca2+), and ρ(NH4+) were (2.48±0.57), (1.22±0.75), (1.18±0.49), and (0.98±0.45) μg·m-3, respectively. The higher Ca2+ concentration also reflected the contribution of dust sources. The ratio of n(NO3-)/n(SO42-) was between 0.63 and 0.85, which indicated that the influence of stationary sources was more important than that of mobile sources. Both Yining Municipal Bureau and the Second Water Plant were affected by motor vehicle exhaust; therefore, their n(NO3-)/n(SO42-) ratios were high. Yining County was in a residential area, and therefore its n(NO3-)/n(SO42-) ratio was lower. The average ρ(OC) and ρ(EC) in PM2.5 were 5.12 μg·m-3(4.67-6.25 μg·m-3) and 0.75 μg·m-3(0.51-0.97 μg·m-3), respectively. Yining Municipal Bureau was significantly affected by motor vehicle exhaust from both sides, so the values of OC and EC concentration were slightly higher than those in other sampling sites. The SOC concentration was calculated by the minimum ratio method, and the results showed that the values of SOC concentration in the New Government Area, the Second Water Plant, and Yining Ecological Environment Bureau were higher than those in other sampling sites. The results of the CMB model showed that PM2.5 in this area mainly came from the contribution of secondary particulate matter and dust sources, which accounted for 33.3% and 17.5%, respectively. Secondary organic carbon (16.2%) was the main contribution source of secondary particulate matter. |
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