基于洗脱称量粒度分析的北京常见树种树叶滞纳大气颗粒物特性

发布时间：2018-04-20 16:34

本文选题：洗脱称量粒度分析法(EWPA) + 大气颗粒物　；参考：《林业科学》2016年12期

【摘要】：【目的】比较树木叶片和塑料叶片单位面积滞纳细颗粒物(PM_(2.5))、可吸入颗粒物(PM_(10))、总悬浮颗粒物(TSP)等大气颗粒物的量,从而区分出受树木叶片结构影响的滞尘量(DRLS)和不受叶片结构影响的滞尘量(DULS),为探索城市树木缓解大气颗粒物污染的贡献及优化树种配置提供科学依据。【方法】以北京市常用的6个绿化树种为对象,持续测定4个季度的叶片滞尘动态,以没有降雨影响的10天为1个试验周期,进行本底采样和颗粒物积累采样,并设置光滑塑料叶片(由自摩擦系数为0.04的聚四氟乙烯塑料制成)对照试验模拟DULS,对采集到的供试样本叶片(含树木叶片和塑料叶片)采用洗脱称量粒度分析法(EWPA),测定10天内各树种叶片单位面积滞尘总量、DULS和对不同粒径颗粒物的滞纳量。【结果】1)滞尘能力最强的侧柏单位叶面积总滞尘量为(124.76±19.27)μg·cm~(-2),是滞尘能力最低的元宝枫的2.24倍,其对PM_(2.5)的滞纳量为(16.92±2.61)μg·cm~(-2)。2)DULS占树木叶片滞尘总量的比例仅为19.65%~42.29%,DRLS所占比例为57.71%~80.35%。3)侧柏的DRLS能力最强,占其滞尘总量80.35%;元宝枫的DRLS能力最弱,占其滞尘总量57.71%;供试针叶树种和阔叶树种的DRLS占滞尘总量的百分比均值分别为77.42%和63.96%。4)针叶树滞纳的各粒级颗粒物中,PM_(2.5)占滞尘总量的13.83%±0.19%,粒径大于10μm的颗粒物占56.82%±1.07%;阔叶树滞纳的各粒级颗粒物中,PM_(2.5)占滞尘总量的8.09%±0.94%,粒径大于10μm的颗粒物占70.29%±3.56%。【结论】树木叶片对大气颗粒物的滞纳具有特异性且作用效果极为显著;供试树种中针叶树滞尘能力显著高于阔叶树,针叶树对小粒径颗粒物滞纳能力较强,而阔叶树对大粒径颗粒物滞纳能力较强。本研究证明绿化树种对缓解大气颗粒物污染有贡献,为合理选择缓解大气颗粒物污染的树种提供科学依据。
[Abstract]:[objective] to compare the amount of PMSP, PMSP, PMSP and PMSP in tree leaves and plastic leaves per unit area. The results show that the DULSs, which are affected by the leaf structure of trees, are distinguished from those which are not affected by the leaf structure. It provides a scientific basis for the exploration of the contribution of urban trees to the mitigation of atmospheric particulate pollution and the optimization of tree species allocation. [methods] Taking six common greening trees in Beijing as objects, The leaf dust retention dynamics of 4 seasons were continuously measured, and the background sampling and particulate matter accumulation sampling were carried out for 10 days without the influence of rainfall as a test cycle. The smooth plastic blade (made of polytetrafluoroethylene plastics with self-friction coefficient 0.04) was simulated by DULS.The sample blades (including tree leaves and plastic leaves) were analyzed by particle size analysis. Within 10 days, the total dust retention per leaf area of each tree species was determined by DULS. [results] [results] 1) the total dust retention per unit leaf area of Platycladus orientalis was 124.76 卤19.27 渭 g cm ~ (-1) 路cm ~ (-2), which was 2.24 times that of Acer truncatum, which had the lowest dust retention ability. The DRLS capacity of Platycladus orientalis was the strongest, accounting for 80.35% of the total dust lag of Acer truncatum, and the DRLS ability of Acer truncatum was the weakest. The percentage of DRLS of coniferous tree species and broadleaved tree species in total dust retention was 77.42% and 63.96.4, respectively. The mean value of DRLS in all grain size particles of coniferous trees was 13.83% 卤0.19%, and that of particles larger than 10 渭 m accounted for 56.82% 卤1.070.The mean value of DRLS in total dust retention was 77.42% and 63.96.4, respectively, and the percentage of PMPMN 2.5 was 13.83% 卤0.19% of the total dust holding capacity of coniferous and broad-leaved trees, and the diameter of particles larger than 10 渭 m accounted for 56.82% 卤1.07m. PMN 2.5) accounted for 8.09% 卤0.94% of the total dust retention, and 70.29% 卤3.56% of the particles larger than 10 渭 m in diameter. [conclusion] the leaves of trees have specificity and remarkable effect on the retention of atmospheric particles. The dust retention ability of coniferous trees was significantly higher than that of broad-leaved trees, and the ability of coniferous trees to absorb particles with small diameter was stronger than that of broadleaved trees. This study proves that greening tree species contribute to the mitigation of atmospheric particulate pollution and provide scientific basis for the reasonable selection of tree species to mitigate atmospheric particulate pollution.
【作者单位】：城乡生态环境北京实验室北京林业大学省部共建森林培育与保护教育部重点实验室;
【基金】：北京市科委项目“首都平原百万亩造林科技支撑工程”(Z121100008512002) 北京市级大学生创新项目(S201410022012)
【分类号】：S718.45;X513

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