我国地表矿物质颗粒物的粒度分布与来源  

Grain size distribution and source of surface mineral particles

作　　者：娄高僮 罗源 陈渔 陈思宇[1] LOU Gaotong;LUO Yuan;CHEN Yu;CHEN Siyu(Key Laboratory of Semi-Arid Climate Change,Ministry of Education,College of Atmospheric Sciences,Lanzhou University,Lanzhou 730000,China;Meteorological Observatory of Hunan Province,Changsha 410118,China)

机构地区：[1]兰州大学大气科学学院半干旱气候变化教育部重点实验室,兰州730000 [2]湖南省气象台,长沙410118

出　　处：《地球环境学报》2023年第2期145-155,共11页Journal of Earth Environment

基　　金：国家自然科学基金项目(U2242209,42175106,91837103);中国博士后科学基金(2020M681156)。

摘　　要：下垫面的地表矿物质颗粒物是大气气溶胶的源和汇,对生物地球化学循环、环境状况和人体健康产生影响。下垫面地表矿物质颗粒物的粒度分布是表征颗粒行为的重要参数,颗粒物的物理性质、化学性质和环境学性质等都与粒径有关。为探究人为下垫面(城市铺装道路、农村土路和农田等)和自然下垫面(沙漠和戈壁)地表矿物质颗粒物的粒径分布,并分析其影响因素,对城市铺装道路、农村土路、裸露农田、沙漠和戈壁下垫面的地表矿物质颗粒物进行粒度研究。结果表明:从沉积物中值粒径来看,城市铺装道路表现为佛山市南海区(254.9μm)>杭州市桐庐县(247.5μm)>北京市(201.3μm)>南平市延平区(178.7μm)>兰州市(65.5μm);赣州市湖江镇农村土路为131.3μm;兰州市榆中县裸露农田为21.1μm;沙漠和戈壁表现为腾格里沙漠(272.7μm)>塔克拉玛干沙漠(121.9μm)。总体来说,地表矿物质颗粒物的粒度分布与人类活动、地理位置、风速和季节等因素密切相关,人类活动对粒度分布的影响因人类活动的复杂而难以明确,风速不同将裹挟不同粒径颗粒物,不同季节风速与风向不同,不同地理位置人类活动与风速存在差异。样本中,除兰州市外,城市铺装道路的地表矿物质颗粒物主要来自土壤、工地和交通活动等局地源,远距离传输来的颗粒物较少;沙漠沉积物的来源为单一的局地物质;沙漠沉积物中重金属含量表现出随粒径变大而减小的趋势。Background,aim,and scope Surface mineral particles on the land cover are the source and sink of atmospheric aerosols,which make significant contributions to biogeochemical cycle,environmental conditions and human health.The particle size distribution of surface mineral particles on the land cover is a kind of vital parameter to characterize particle behavior,and the physical,chemical and environmental properties of particulate matters are related to particle size.Due to the influence of natural and anthropogenic activities,the formation,characteristics,release and transportation of surface mineral particles on distinct land covers vary significantly.For the purpose of revealing the impact of surface mineral particles on natural and anthropogenic disturbed land covers,the particle size of surface mineral particles on the bottom surface of urban paved roads,rural dirt roads,deserts and farmland is studied in this paper.Materials and methods Sand grains with a depth of 0—1 cm on the surface are collected uniformly in the desert;urban paved roads,rural dirt roads and bare farmland are collected using brushes and shovels with approximately 30 g per sample.For urban paved road sampling,the specific sampling area is an area near the curb(1—2 m).For farmland and rural dirt road sampling,the winter fallow period was chosen.The collected samples are naturally air-dried for 24 h,as well as the samples are filtered through a clean 20-mesh standard inspection sieve to remove plant debris,hairs,pebbles and other debris.The filtered samples are stored in sealed bags and used as the original samples.The particle size tests are tested by Malvern Mastersizer 2000 laser particle size analyzer and the composition tests are performed by a Magic PW2403 X-ray fluorescence spectrometer.Results As for the size of median diameter,in terms of urban pavement,Nanhai District of Foshan City(254.9μm)>Tonglu County of Hangzhou City(247.5μm)>Beijing City(201.3μm)>Yanping District of Nanping City(178.7μm)>Lanzhou City(65.5μm);while for d

关 键 词：地表矿物质颗粒物 粒度分布 沙漠 城市铺装道路 农村土路 重金属 

分 类 号：X513[环境科学与工程—环境工程]