| 中原城市群典型城市秋冬季大气PM2.5污染特征及溯源 |
| 摘要点击 3583 全文点击 1052 投稿时间：2020-05-31 修订日期：2020-07-04 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 PM2.5 无机元素 二次生成 化学质量平衡(CMB) 潜在源 |
| 英文关键词 PM2.5 inorganic elements secondary generation chemical mass balance (CMB) potential source |
|
| 中文摘要 |
| 为了研究中原城市群区域城市秋冬季大气PM2.5的污染特征和其主要成分的潜在来源，于2018年10月到2019年1月在郑州、洛阳、安阳和新乡这4个典型城市展开秋冬季连续4个月PM2.5膜样本采集，采用X射线荧光光谱法，碳分析法和离子色谱法分别对18种无机元素，有机碳（OC）/元素碳（EC），和9种水溶性无机离子进行了测定.根据PM2.5日均值浓度水平分为3个污染等级，并分别通过对氮氧化率（NOR）和二次有机碳（SOC）及富集因子的计算结果对PM2.5主要成分NO3-和SOC及18种无机元素的时空变化进行了对比分析.通过化学质量平衡（CMB）模型计算了4个城市的排放源及贡献率，并通过后向轨迹（HYSPLIT）模型和潜在源贡献因子法（PSCF）分析了4个城市PM2.5和主要成分NO3-及OC的潜在污染来源.结果表明，采样期间郑州、洛阳、安阳和新乡PM2.5均值分别为（82.1±45.5）、（84.7±39.8）、（96.8±46.1）和（81.1±36.6）μg·m-3，日均值的最高浓度值分别是国家二级标准的3.3、2.6、3.0和2.3倍；4个城市PM2.5的主要组分都为NO3-和SOC，NO3-的浓度，NO3-/EC和NOR都随着污染等级的升高而显著升高，NO3-/EC和NOR的均值随着污染等级的升高总体上表现出郑州和洛阳略高于安阳和新乡；SOC的浓度和在OC中的占比及SOC/EC的比值都随着污染等级的升高而增大；从无机元素的浓度和富集程度来看，As在郑州最高，Mn和Fe在洛阳最高，Zn、Ni和Cr在安阳最高以及Cu和Pb在新乡最高；4个城市PM2.5污染源为二次硝酸盐、二次硫酸盐、有机物、燃煤源、机动车源、扬尘源、生物质源和工艺过程源，二次硝酸盐的分担率在郑州（37.7%）最高，新乡（14.1%）机动车分担率最高，洛阳（7.0%）和安阳（6.8%）的工业过程源的分担率相对较高；郑州、洛阳、安阳和新乡分别有51.6%、49.2%、49.6%和46.3%的气流来自西北方向；郑州潜在污染区域主要集中在河南省，洛阳主要在河南省南部和汾渭平原，安阳和新乡则是主要在河南省和京津冀传输带上，另外安徽西北部、山东西南部、山西东南部和陕西北部也对安阳和新乡OC的污染造成了影响. |
| 英文摘要 |
| To study the characteristics of PM2.5 pollution and the potential sources of its main components in the central plain urban agglomeration in autumn and winter, PM2.5 samples were collected continually in the four typical cities of Zhengzhou, Luoyang, Anyang, and Xinxiang from October 2018 to January 2019. X-ray fluorescence spectrometry, carbon analysis methods, and ion chromatography were used to determine 18 kinds of inorganic elements, organic carbon (OC)/elemental carbon (EC), and 9 kinds of water-soluble inorganic ions. According to the daily PM2.5 concentration, three pollution levels were divided, and the comparative analysis for the spatial and temporal variation of PM2.5 and its main components, i.e., NO3-, OC, and 18 kinds of inorganic elements, were studied via the calculation of the nitrogen oxidation rate (NOR), secondary organic carbon (SOC), and enrichment factor. The emission sources and their contribution rates of PM2.5 pollution level in the four cities were calculated by a chemical mass balance (CMB) model; the potential pollution sources of PM2.5 and its main components, NO3- and OC, in the four cities were analyzed by a backward trajectory model (HYSPLIT) and potential source contribution factor method (PSCF). The results showed that the means of PM2.5 in Zhengzhou, Luoyang, Anyang, and Xinxiang were (82.1±45.5), (84.7±39.8), (96.8±46.1), and (81.1±36.6) μg·m-3, respectively, during the sampling period, and the maximum daily mean values were 3.3, 2.6, 3.0, and 2.3 times, respectively, of the Chinese national secondary standard; the main components of PM2.5 in the four cities were NO3- and SOC, and the concentration of NO3-, the ratio of NO3-/EC, and NOR all increased significantly with the rising of pollution levels, generally showing that the mean values of NO3-/EC and NOR of Zhengzhou and Luoyang were a little higher than those of Anyang and Xinxiang; the concentration of SOC, the proportion of SOC in OC, and the ratio of SOC/EC all increased with the rising of pollution levels. From the concentration and enrichment degree of inorganic elements, As was the highest in Zhengzhou; Mn and Fe were the highest in Luoyang; Zn, Ni, and Cr were the highest in Anyang; and Cu and Pb were the highest in Xinxiang. Secondary nitrate, secondary sulfate, organic matter, coal combustion, motor vehicle, dust, biomass burning, and industrial processes were the main PM2.5 pollution sources in the four cities, with the highest contribution rate of secondary nitrate in Zhengzhou (37.7%), the highest contribution rate of vehicle sources in Xinxiang (14.1%), and a relatively high contribution rate of industrial process source in Luoyang (7.0%) and Anyang (6.8%). The northwest direction of airflow contributed 51.6%, 49.2%, 49.6%, and 46.3% of the total airflow in Zhengzhou, Luoyang, Anyang, and Xinxiang, respectively. From the potential pollution area of each city, the Zhengzhou area was mainly concentrated in Henan province, the Luoyang area was mainly concentrated in the south of Henan province and Fen-wei plain, and the Anyang and Xinxiang areas were mainly concentrated in Henan province and the Beijing-Tianjin-Hebei transport belt. The pollution levels of OC in Anyang and Xinxiang were also affected by the northwest Anhui, southwest Shandong, southeast Shanxi, and north Shaanxi. |
|
|
|
