An investigation on the leaf accumulation-removal efficiency of atmospheric particulate matter for five urban plant species under different rainfall regimes
An investigation on the leaf accumulation-removal efficiency of atmospheric particulate matter for five urban plant species under different rainfall regimes
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不同雨况下5种城市植物叶片对大气颗粒物的累积去除效率研究
DOI：
10.1016/j.atmosenv.2019.04.010
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发表时间：
2019-07-01
影响因子：
5
通讯作者：
McNulty, Steven
中科院分区：
文献类型：
--
作者：
Zhang, Lu;Zhang, Zhiqiang;McNulty, Steven
城市树木和森林被广泛用作生物过滤器，以对抗空气中的颗粒物（PM）。降水对植物叶片颗粒物的冲刷作用被认为是对过滤器的清洗，是恢复植物叶片颗粒物过滤功能的关键。然而，它是不确定的，有多少PM可以过滤的城市树木，由于缺乏了解如何PM沉积，去除，再悬浮和再沉积与物种和降雨变异。为此，我们开展了一项研究，以确定叶片PM去除量和不同大小的5种常用的城市绿化植物模拟不同的降雨条件下的速率。我们的具体目标是：（1）探索不同植物物种和不同降雨模式之间PM去除的差异;（2）了解叶片PM去除随降雨特征的变化的响应;（3）量化叶片PM去除率之间的关系和叶子粗糙度。结果表明，同一雨型下不同树种间和同一树种不同雨型间的PM去除量和去除率均存在显著差异（P < 0.05），叶片表面PM去除率与雨强呈显著正相关（P < 0.01）。不同粒径颗粒物累积去除率随降雨历时呈指数损失（P < 0.01）。对于光滑叶面，长时间低强度降雨可以提高PM的去除率，而对于粗糙叶面，短时间高强度降雨可以在相同的总降雨量下达到更大的去除率。降雨对颗粒物的去除率高于水洗。这项研究的结果具有更好地估计城市植物的长期空气净化潜力，并在城市地区的空气植物修复规划的影响。
Urban trees and forests are widely used as biological filters to combat the airborne particulate matter (PM). Precipitation washing PM off from plants is regarded as filter cleaning, which is a key factor for recovering the function of foliar PM filtering. However, it is uncertain on how much PM can be total filtered by urban trees due to lack of understanding about how PM deposition, removal, resuspension and redeposition interact with species and rainfall variability. For this reason, we developed a study to determine foliar PM removal amount and rate of different sizes for five plant species commonly used for urban greening by simulated different rainfall regimes. Our specific objectives were to: (1) explore the difference in PM removal between different plant species and different rainfall patterns; (2) understand the response of foliar PM removal as a function of rainfall characteristics; and (3) quantify the relationship between foliar PM removal rate and leaf coarseness. Results showed that significant differences (P < 0.05) in PM removal amount and rate were found not only between different species within the same rainfall pattern, but also between different rainfall patterns for the same species, PM removal rates from the leaf surface were significantly correlated with rainfall intensity (P < 0.01). Different size PM cumulative removal rate exhibited an exponential loss with rainfall duration (P < 0.01). For smooth leaf surfaces, long duration-low intensity rainfall could increase PM removal rate while for rough leaf surfaces, short duration-high intensity rainfall could achieve a larger removal rate using the same amount of total rainfall. Additionally, more PM was removed by rainfall than that by water washing. The findings from this study have implications for better estimating long-term air purification potential of urban plants, and for air phytoremediation planning in urban areas.