On-line measurement of fluorescent aerosols near an industrial zone in the Yangtze River Delta region using a wideband integrated bioaerosol spectrometer
On-line measurement of fluorescent aerosols near an industrial zone in the Yangtze River Delta region using a wideband integrated bioaerosol spectrometer
复制标题
利用宽带集成生物气溶胶光谱仪在线测量长三角地区工业区附近的荧光气溶胶
DOI：
10.1016/j.scitotenv.2018.11.370
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发表时间：
2019
影响因子：
9.8
通讯作者：
Jun Zheng
中科院分区：
文献类型：
--
作者：
Yan Ma;Wang Zhibin;Dongsen Yang;Yiwei Diao;Weiwei Wang;Hongliang Zhang;Wenhui Zhu;Jun Zheng
在这项工作中，我们提出了在线荧光气溶胶测量宽带集成生物气溶胶光谱仪（WIBS-4A）在南京，长江三角洲（YRD）地区的特大城市的工业区附近。实地调查于2014年4月1日至5月8日进行。TSI 3321型气溶胶粒度分析仪（APS）同时用于测量0.8 ~ 20 μm气溶胶的总数粒径分布。WIBS-4A和APS报告了相似的数量浓度和时间分布（R2= 0.72）。然而，潜在的生物气溶胶的日平均数只有0.5 ± 0.2%的总粒子检测的WIBS-4A，并显示了一个完全不同的日廓线从APS。此外，WIBS-4A只能提供完整的荧光信号，这极大地限制了特异性识别生物气溶胶的潜力。因此，层次凝聚聚类分析（HACA）被用来识别和形态的潜在生物气溶胶从WIBS-4A数据集。通过最大化所有潜在聚类中心之间的总距离，12个聚类的解决方案被认为是最佳的结果。根据它们的荧光特征、大小和形态进一步鉴定这些簇，即，非生物气溶胶、细菌和真菌孢子和/或花粉碎片。细菌是这项工作中检测到的主要生物气溶胶物种。生物气溶胶的昼夜分布与相对湿度（RH）相关性很好，在凌晨3点~6点左右达到每日最大值，表明存在湿度控制的生物气溶胶排放机制，即，细菌可在适度的环境温度、相对湿度和没有紫外线辐射的情况下繁殖。生物气溶胶的大小和AF分布表明，生物气溶胶通常在大小上变化很大，并假定一个相当不规则的形状。虽然生物气溶胶的数量浓度相对较小，但大多数生物气溶胶可以通过提供粗糙和不规则的表面来有效地充当冰核，这一点已被观测结果所证实。因此，WIBS-4A测量仍然可以为大气中生物气溶胶的研究提供信息，特别是当将HACA方法纳入数据处理时。
In this work, we present on-line fluorescent aerosol measurements by the wideband integrated bioaerosol spectrometer (WIBS-4A) near an industrial zone in Nanjing, a megacity in the Yangtze-River-Delta (YRD) region. The fieldwork was conducted from April 1 to May 8, 2014. A TSI. 3321 aerosol-particle-sizer (APS) was simultaneously deployed to measure the total number size distribution of aerosol with diameter from 0.8–20 μm. Both WIBS-4A and APS reported similar number concentration and temporal profiles (R2= 0.72). However, the daily average number of potential bioaerosols was only 0.5 ± 0.2% of the total particles detected by the WIBS-4A and displayed a completely different diurnal profile from that of APS. In addition, WIBS-4A can only provide integrated fluorescent signals, which strongly limited the potential to specifically identify the bioaerosols. Accordingly, hierarchical-agglomerative-cluster-analysis (HACA) was utilized to identify and speciate the potential bioaerosols from the WIBS-4A dataset. By maximizing the total distances among all potential cluster centers, a 12-cluster solution was accepted as the optimum result. These clusters were further identified according to their fluorescent signatures, size, and morphology, i.e., non-bioaerosols, bacteria, and fungal spores and/or pollen fragments. Bacteria were the dominant bioaerosol species detected in this work. The diurnal profiles of bioaerosols correlated very well with relatively humidity (RH), reaching daily maxima around 3 AM~6 AM, indicating the presence of humidity controlled bioaerosol emission mechanism, i.e., bacteria may flourish under moderate ambient temperature, RH, and the absence of UV radiation. The size- and AF-distributions of bioaerosols indicated that bioaerosols normally varied substantially in size and assumed a rather irregular shape. Although the number concentration of bioaerosols was relatively small, most bioaerosols can efficiently serve as ice nuclei by providing rough and irregular surfaces, verified by the observation results. Therefore, WIBS-4A measurements can still be informative for investigations of bioaerosols in the atmosphere, especially when HACA method was incorporated into the data processing.