利用快速检测法研究石家庄道路交通扬尘排放特征

利用快速检测法(TRAKER)实时监测石家庄夏季铺装道路机动车道PM_(2.5)、PM_(10)的背景浓度和在机动车行驶过程中车轮扬起的PM_(2.5)、PM_(10)浓度,分析车速对PM_(2.5)、PM_(10)排放特征的影响,并得到不同类型道路积尘负荷、排放因子和排放强度。结果表明:车轮扬起的PM_(2.5)浓度随车速变化不大,而PM_(10)起伏较大;车速相同时,快速路、主干道、次干道、支路的PM_(2.5)质量浓度分别为0.046、0.110、0.160、0.097mg/m~3,表现为次干道主干道支路快速路,与积尘负荷的强弱顺序一致;不同类型道路排放因子表现为次干道快速路支路主干道,排放强度表现为快速路次干道主干道支路。研究结果可为石家庄道路交通扬尘排放清单的构建以及扬尘的治理提供数据支撑和参考。     

基于移动采样法的石家庄市秋冬季道路扬尘PM_(2.5)排放清单

以石家庄城市道路扬尘为研究对象,于2014~2015年秋冬季采用移动式采样法收集不同类型道路积尘。分析道路积尘负荷、道路积尘粒径分布特征、车流量和平均车重等数据,计算得出石家庄道路扬尘PM_(2.5)排放因子和排放量。通过地理信息系统软件(GIS)提取研究区域道路信息,制作道路矢量化图,并结合道路扬尘PM_(2.5)排放因子和排放量,建立排放清单。结果表明,秋季各道路扬尘PM_(2.5)排放因子为0.003~0.103 g·VKT~(-1),冬季各道路扬尘PM_(2.5)排放因子为0.004~0.016 g·VKT~(-1);秋、冬两季不同类型道路扬尘PM_(2.5)排放因子分布特征为快速路主干道次干道支路;秋季道路扬尘PM_(2.5)排放量为6.47~53.07 t,冬季为3.47~12.02 t,秋季排放量大于冬季排放量,秋、冬两季道路扬尘PM_(2.5)排放量分布特征为快速路支路主干道次干道。     

天津市夏季城区道路不同车道积尘负荷的关系

采用改进的移动式铺装道路积尘采样方法于夏季采集天津市城区不同类型道路各车道的道路积尘样品,计算出积尘负荷,并分析积尘负荷的变化规律。结果表明:天津市区外环线、快速路、主干道、次干道和支路的路面积尘负荷分别为0.06、0.10、0.21、0.22和0.28 g·m-2,天津市道路路面积尘污染强弱顺序为支路次干道主干道快速路外环线;对于次干道与支路,不同车道路面积尘负荷差异不大;对于外环线(1车道除外)、快速路和主干道,越接近道路中央积尘负荷越小,且4车道(即慢车道)积尘负荷与其他各车道积尘负荷之间存在线性关系。     

北京市道路扬尘时空变化特征的研究

道路扬尘已成为城市颗粒物重要来源之一。为了甄选有效的采样测试方法,分别采用降尘法和积尘负荷法对北京市4种不同类型的道路扬尘进行采集,通过分析获得降尘量和积尘负荷的时空变化规律。结果显示:降尘量夏季明显高于秋季,在次干道和支路上,采样高度1.5、2.5m的降尘量差异不大,在夏季差值分别为0.193 0、0.122 4g/(m~2·d),在秋季差值分别为0.037 1、0.013 3g/(m~2·d);而主干道和快速路上,1.5 m高度的降尘量明显大于2.5 m高度,在夏季差值分别为0.268 6、0.464 6g/(m~2·d),在秋季差值分别为0.111 0、0.353 9g/(m~2·d);道路积尘负荷夏季高于秋季,在夏季表现为支路次干道主干道快速路,其积尘负荷从大到小依次为2.758 9、1.976 7、1.787 8、1.547 5g/m~2,在秋季表现为次干道支路快速路主干道,其积尘负荷从大到小依次为1.920 2、1.822 9、1.430 6、0.201 5g/m~2。随着车流量增大和车速加快,积尘负荷逐渐降低。研究结果能为北京市在道路扬尘采样方法的选择和颗粒物控制上提供理论依据。     

渭南主城区道路积尘负荷及交通扬尘颗粒物排放

对渭南主城区道路积尘负荷进行了实测,并计算了2018年不同道路类型和不同车型的交通扬尘颗粒物排放量。结果表明:渭南主城区支路积尘负荷最大,为1.79g/m~2,高速积尘负荷最小,为0.05g/m~2,洒水作业能有效降低积尘负荷;渭南主城区道路交通扬尘PM_(2.5)和PM_(10)的年排放量分别为1 149.65、4 751.88t;小型客车引起的交通扬尘颗粒物排放在城市道路(包括主干道、次干道、支路)和国省道(包括国道和省道)上的分担率最高,分别为59.49%、41.46%,重型货车在高速上的分担率最高,为63.35%;城市道路交通扬尘颗粒物排放有明显的双峰日变化规律,而国省道和高速不明显。     

石家庄城市道路积尘负荷排放特征研究

采用移动式采样法,于2014年秋季、冬季和2015年春季、夏季采集了石家庄4种道路类型(快速路、主干道、次干道和支路)两侧的快、中、慢车道的积尘,分析了不同季节、不同道路类型、不同速度车道以及不同方向车道的积尘负荷分布特征。结果表明:4个季节的平均积尘负荷为秋季0.111g/m~2、冬季0.027g/m~2、春季0.055g/m~2、夏季0.046g/m~2;不同道路类型的平均积尘负荷为快速路0.084g/m~2、主干道0.038g/m~2、次干道0.043g/m~2、支路0.048g/m~2;不同速度车道平均积尘负荷为快车道0.039g/m~2、中车道0.048g/m~2、慢车道0.079g/m~2;不同方向车道积尘负荷差别不大,且大体上显著相关,说明主导风向对道路积尘的影响不大,而车流量的影响较大。     

AP-42道路交通扬尘排放模型评估及其在北京市的应用

对EPA推导AP-42模型的源数据划分范围,评估不同积尘负荷范围的线性回归模型的模拟效果。结果显示,在不同积尘负荷范围内(0~0.5、0.5~1、0~1、0~4和5~400 g/m2),线性回归模型参数以及方程R2值均有差异。对182个北京市道路积尘样品进行频数分布分析,发现积尘负荷主要分布在0~0.5 g/m2或0~1 g/m2范围内,分别运用道路积尘负荷0~0.5、0.5~1和0~1 g/m2范围的模拟回归模型,评估北京市铺装道路PM10的排放特征,尽管3个不同模型评估结果的平均值的比例是4∶2∶1,但是3个模型评估不同类型道路PM10排放因子的大小顺序是:支路次干道主干道快速路。     

石家庄市夏季道路交通扬尘排放特征研究

利用石家庄市快速路、主干道、次干道、支路共8条道路上布设的降尘缸,收集夏季道路交通扬尘并进行样品筛分、称重、粒径分析及碳分析。结果表明:(1)2.5~10.0μm粒径颗粒物含量最高,其次为10.0~30.0μm,0~2.5μm最少。相同类型道路南侧、西侧细颗粒物多,而北侧、东侧大颗粒物相对多,原因与道路两侧车流量和周围环境有关。2.5~10.0μm颗粒物更易在2.5 m处富集,而10.0~30.0μm颗粒物在1.5 m处容易富集。(2)PM_(2.5)比PM10更易富集碳。快速路PM_(2.5)中总碳(TC)、有机碳(OC)高,元素碳(EC)低。快速路和主干道2.5 m处PM10更易富集碳,次干道和支路则更易在1.5 m处富集。(3)研究区道路扬尘PM_(2.5)和PM10中碳组分的主要来源为汽油车尾气和燃煤排放,少部分为生物质燃烧。     

唐山市典型道路积尘负荷分布特征研究

为研究唐山市典型道路积尘负荷分布特征,于2019年1、4、7月基于样方真空吸尘法采集样品,通过筛分称重获得道路积尘负荷,并探讨其时空分布特征.结果表明:(1)不同类型道路积尘负荷排序为支路((0.70±0.85)g/m2)>环线((0.50±0.47)g/m2)>次干道((0.30±0.25)g/m2)>主干道((0....     

天津市秋季道路降尘分布特征

2014年秋季在天津市主城区布设88个道路降尘采样点,每个采样点设置2个采样高度,共采集176个样品。利用重量法计算得到降尘负荷,使用SPSS进行统计分析,研究了天津市秋季道路降尘的分布特征。结果表明:(1)1.5m处的降尘负荷中位值高于2.5m处;(2)不同道路类型的降尘负荷为外环线快速路主干道支路次干道;(3)东西走向道路的南北两侧的降尘负荷差异显著,这可能与采样期间的主导风向有关。     

球团竖炉烟尘除尘脱硫净化技术设备

本文介绍了球团竖炉的烟尘排放特性 ,分析了烟尘回收效益及脱硫、除尘、除雾一体化技术设备 ,该技术设备是一种紧凑合理、高效耐用、性价比高、管理方便、适合国情的大气环境净化技术设备     

Possible reuse of Egyptian controlled cement dust

Possibilities for the reuse of controlled cement dust, collected from the hopper of the electrostatic precipitators installed on the different cement kilns of two of the three biggest companies for Portland cement production located to the south of Cairo, have been investigated. Twenty-one factors representing the physical properties and mineral and chemical composition of the cement dust were estimated and discussed. The results have been compared with the corresponding figures of three Portland cement companies in the United Arab Emirates and also with the British Standard Requirements of ordinary Portland cement. The study found that the cement dust can be reused after some feasible treatments, such as increasing the fineness and tricalcium silicate ratio and decreasing its alkalinity. Consequently, in this circumstance, pollution prevention at source is proving to be a boon as it can not only bring down pollution levels but also add to the companies' profits through efficient use of resources.     

表面活性剂对叶面滞尘作用的影响

表面活性剂能够增强植物叶面滞尘能力,研究不同表面活性剂对植物滞尘能力的影响,对于利用植物防治粉尘污染有重要意义。以LAS、DTAB、AR和APG200为喷洒试剂,研究了8种植物吸附表面活性剂后滞留粉尘的重量、组分。结果表明,LAS浓度、植物种类、表面活性剂类型对滞尘量和面积比具有显著影响(P0.05);表面活性剂能够有效提高植物滞尘能力,LAS、DTAB效果优于生物型AR、APG200,且测试叶面滞尘量的变化与叶面接触角无明显关系;LAS使除朴树外所有植物的滞尘能力增加的浓度为0.2 g/L,而对滞留粉尘组分改变较大的浓度为0.5 g/L;此外,表面活性剂能改变滞留粉尘的组分,但不具有明显的规律性,粉尘的遮光比变化趋势与叶面滞尘量基本相似。     

Trajectories of advected Saharan dust in Nigeria

Widespread and intense thick dust spells originating from Niger and Chad Republics affected the whole of Nigeria (see Fig. 1) between 2 and 11 March 1977.The trajectories of the various spells were followed using 0900 GMT visibility isoline analysis as control and 1500 GMT visibility analysis for the monitoring, on the basic assumption that where visibility deteriorates when diurnal improvement is anticipated spells associable with meso or synoptic disturbances must be at play.The trajectories were traced to Southern Nigeria where discrete visibility ‘lows’ were established with centres at Ilorin (65101), Benin (65229) and Calabar (65264) from 6 to 8 March (see Appendix II on World Meteorological Organization's Station Numbering). These centres were better defined at 1500 GMT and are fundamental observations hitherto glossed over.The poleward surge of the Intertropical Discontinuity (ITD) (7–9 March) was associated with moisture in flux which resulted in a mean clearance rate of about 500 m per latitude surge per day.The weight of Harmattan Dust in suspension (the annual removal of top soil in the source region results not only in atmospheric pollution down stream but also aggravates desertification at source) between 770 m and the surface area of Nigeria was calculated to be approximately 1.6 × 10⁹ kg on 5 March 1977 when the poorest visibility was most widespread (see Fig. 4 and Appendix 1).     

Wind modeling of Chihuahuan Desert dust outbreaks

The Chihuahuan Desert region of North America is a significant source of mineral aerosols in the Western Hemisphere, and Chihuahuan Desert dust storms frequently impact the Paso del Norte (El Paso, USA/Ciudad Juarez, Mexico) metropolitan area. A statistical analysis of HYSPLIT back trajectory residence times evaluated airflow into El Paso on all days and on days with synoptic (non-convective) dust events in 2001–2005. The incremental probability—a measure of the areas most likely to have been traversed by air masses arriving at El Paso during dusty days—was only strongly positively associated with the region west–southwest of the city, a zone of known dust source areas. Focused case studies were made of major dust events on 15 April and 15 December 2003. Trajectories approached the surface and MM5 (NCAR/Penn State Mesoscale Model) wind speeds increased at locations consistent with dust sources observed in satellite imagery on those dates. Back trajectory and model analyses suggested that surface cyclones adjacent to the Chihuahuan Desert were associated with the extreme dust events, consistent with previous studies of dust storms in the Southern High Plains to the northeast. The recognition of these meteorological patterns serves as a forecast aid for prediction of dust events likely to impact the Paso del Norte.     

The effects of dust on vegetation--a review

An increase in quarrying, open-cast mining and road traffic suggest that dust deposition onto vegetation may be increasing. This review describes the physical and chemical characters of a range of dust types. The effects of dust on crops, grasslands, heathlands, trees and woodlands, arctic bryophyte and lichen communities are identified. Dust may affect photosynthesis, respiration, transpiration and allow the penetration of phytotoxic gaseous pollutants. Visible injury symptoms may occur and generally there is decreased productivity. Most of the plant communities are affected by dust deposition so that community structure is altered. Epiphytic lichen and Sphagnum dominated communities are the most sensitive of those studied. However, there have been very few detailed studies on natural and semi-natural systems and some dust types are also very understudied. Recommendations for future research are made in order to overcome this deficiency.     

捕集植物纤维性粉尘的研究

植物纤维性粉尘因其固有特性 ,在除尘技术中是一个没有解决好的难题。通过理论分析、实验研究与工程应用 ,利用流化床除尘器解决了这一问题 ,实现了除尘器的高效、低阻和可靠运行     

Chemical aspects of Indian varieties of asbestos dust

Actinolite, anthophyllite, amosite, chrysotile and tremolite varieties of asbestos from Indian mines were analysed for their chemical composition. Significant differences were found as compared with the composition of corresponding foreign varieties. The significance of this in relation to their possible toxic effects and the need for toxicological work with Indian varieties are discussed.