School of Water, Energy and Environment, Cranfield University, Cranfield MK43 0AL, UK.
School of Environmental Studies, China University of Geosciences, Wuhan 430074, PR China; School of Water, Energy and Environment, Cranfield University, Cranfield MK43 0AL, UK.
Sci Total Environ. 2020 Jun 15;721:137629. doi: 10.1016/j.scitotenv.2020.137629. Epub 2020 Feb 29.
Bioaerosol emissions from wastewater treatment plants may pose adverse health impact on workers and nearby communities. To detect and characterise bioaerosol emissions from wastewater treatment plant (WWTP), a novel real-time bioaerosol sensor, Spectral Intensity Bioaerosol Sensor (SIBS) was employed at a WWTP and a background site. The SIBS records a range of data (size, shape, and fluorescence emission across 16 wavelength bands from 298 to 735 nm for two excitation wavelengths (285 nm and 370 nm)) on single particles in real time. Additionally, excitation-emission matrix (EEM) of wastewater samples obtained by a spectrofluorometer was compared with SIBS spectra from WWTP. The results showed that the average number concentrations of total particles (NT) and fluorescence particles (NF) were both higher at the WWTP (NT = 2.01 cm, NF = 1.13 cm) than the background site (NT = 1.79 cm, NF = 1.01 cm). The temporal variation of NF and NT was highly variable at the WWTP and the concentration peaks were consistent with on-site activities. Moreover, the time-resolved number-size distribution of fluorescent particles revealed the predominance of fine scale particles (<1 μm) and the time-series channel by channel number concentrations demonstrated the temporal variability of dominant bio-fluorophores. Furthermore, the overall and size-segregated fluorescence spectra at two sites were multimodal. In particular, the fluorescence intensity increases with increasing particle size in WWTP spectra, which is not present in the background spectra. In addition, the highly resolved SIBS fluorescence spectra were broadly similar to EEM of wastewater. These findings confirmed that the spectrally resolved fluorescence detected by SIBS is capable of providing reliable bio-fluorophores information of bioaerosol emissions generated from wastewater, thus holding the potential for better characterisation of bioaerosols in real time.
污水处理厂的生物气溶胶排放可能对工人和附近社区的健康造成不利影响。为了检测和描述污水处理厂（WWTP）的生物气溶胶排放，在一个 WWTP 和一个背景点使用了一种新型实时生物气溶胶传感器，即光谱强度生物气溶胶传感器（SIBS）。SIBS 实时记录单个颗粒的一系列数据（大小、形状和在 298 至 735nm 之间的 16 个波长带的荧光发射，激发波长为 285nm 和 370nm）。此外，还比较了荧光分光光度计获得的废水样品的激发-发射矩阵（EEM）与 WWTP 的 SIBS 光谱。结果表明，总颗粒（NT）和荧光颗粒（NF）的平均数浓度在 WWTP 处均高于背景点（NT=2.01cm，NF=1.13cm）（NT=1.79cm，NF=1.01cm）。在 WWTP 处，NF 和 NT 的时间变化高度可变，浓度峰值与现场活动一致。此外，荧光颗粒的时间分辨数-尺寸分布揭示了细颗粒（<1μm）的优势，时间序列通道-通道数浓度表明主要生物荧光团的时间可变性。此外，两个地点的总荧光和尺寸分离荧光光谱均呈多峰模式。特别是，在 WWTP 光谱中，荧光强度随颗粒尺寸的增加而增加，而在背景光谱中则不存在这种情况。此外，高分辨率的 SIBS 荧光光谱与废水的 EEM 广泛相似。这些发现证实，SIBS 检测到的光谱分辨荧光能够提供可靠的生物气溶胶排放生物荧光团信息，因此具有实时更好地描述生物气溶胶的潜力。
