Separating emitted dust from the total suspension in airflow based on the characteristics of PM10 vertical concentration profiles on a Gobi surface in northwestern China

During aeolian processes,the two most critical factors related to dust emissions are soil particle and aggregate saltation,which greatly affect the vertical profiles of near-surface dust concentrations.In this study,we measured PM10 concentrations at four different heights(0.10,0.50,1.00 and 2.00 m)with and without continuous and simultaneous aeolian saltation processes on a Gobi surface in northwestern China from 31 March to 10 April,2017.We found that the vertical concentration profiles of suspended PM10 matched the log-law model well when there was no aeolian saltation.For the erosion process with saltation,we divided the vertical concentration profiles of PM10 into the saltation-affected layer and the airflow-transport layer according to two different dust sources(i.e.,locally emitted PM10 and upwind transported PM10).The transition height between the saltation-affected layer and the airflow-transport layer was not fixed and varied with saltation intensity.From this new perspective,we calculated the airflow-transport layer and the dust emission rate at different times during a wind erosion event occurred on 5 April 2017.We found that dust emissions during wind erosion are primarily controlled by saltation intensity,contributing little to PM10 concentrations above the ground surface compared to PM10 concentrations transported from upwind directions.As erosion progresses,the surface supply of erodible grains is the most crucial factor for saltation intensity.When there was a sufficient amount of erodible grains,there was a significant correlation among the friction velocity,saltation intensity and dust emission rate.However,when supply is limited by factors such as surface renewal or an increase in soil moisture,the friction velocity will not necessarily correlate with the other two factors.Therefore,for the Gobi surface,compared to limiting dust emissions from upwind directions,restricting the transport of suspended dust in its path is by far a more efficient and realistic option for small areas that are often exposed to dust storms.This study provides some theoretical basis for correctly estimating PM10 concentrations in the Gobi areas.

Elemental composition and risk assessment of heavy metals in the PM10 fractions of road dust and roadside soil

A total of 64 dust samples were analyzed to determine the size distribution and elemental composition of the PM10 fraction, including42 road dust(RD), 12 roadside soil(RSD), and 10 park road dust(PRD) samples. The mass of dust smaller than 20μm was dominated by particles sized 2.5-16 μm, which accounted for 85%, 88%, and 87% of the RD, PRD, and RSD, respectively. Additionally, crustal elements accounted for 30.14%, 36.35%, and 37.14% of the PMio fractions of the RD, RSD, and PRD, respectively. The most abundant trace elements in RD, RSD, and PRD were Zn, Mn, and Cu (range, 277 to 874 mg/kg). Moreover, the /geo values revealed all dusts were contaminated with Pb, Zn, Cu, Sb, Sn, and Cd. Health risk assessment showed that Mn, Ni, Cu, Zn, Cd, Sb, and Pb in the PM10 fraction of three types of dusts posed non-cancer risks to children but posed no non-cancer risk to adults. Additionally, As, Ni, and Cd posed no cancer risk to inhabitants.

Comparative Analysis of PM10 Emission Rates from Controlled and Uncontrolled Cement Silos in Concrete Batching Facilities

This research study quantifies the PM10 emission rates (g/s) from cement silos in 25 concrete batching facilities for both controlled and uncontrolled scenarios by applying the USEPA AP-42 guidelines step-by-step approach. The study focuses on evaluating the potential environmental impact of cement dust fugitive emissions from 176 cement silos located in 25 concrete batching facilities in the M35 Mussafah industrial area of Abu Dhabi, UAE. Emission factors are crucial for quantifying the PM10 emission rates (g/s) that support developing source-specific emission estimates for areawide inventories to identify major sources of pollution that provide screening sources for compliance monitoring and air dispersion modeling. This requires data to be collected involves information on production, raw material usage, energy consumption, and process-related details, this was obtained using various methods, including field visits, surveys, and interviews with facility representatives to calculate emission rates accurately. Statistical analysis was conducted on cement consumption and emission rates for controlled and uncontrolled sources of the targeted facilities. The data shows that the average cement consumption among the facilities is approximately 88,160 (MT/yr), with a wide range of variation depending on the facility size and production rate. The emission rates from controlled sources have an average of 4.752E-04 (g/s), while the rates from uncontrolled sources average 0.6716 (g/s). The analysis shows a significant statistical relationship (p < 0.05) and perfect positive correlation (r = 1) between cement consumption and emission rates, indicating that as cement consumption increases, emission rates tend to increase as well. Furthermore, comparing the emission rates from controlled and uncontrolled scenarios. The data showed a significant difference between the two scenarios, highlighting the effectiveness of control measures in reducing PM10 emissions. The study’s findings provide insights into the impact of cement silo emissions on air quality and the importance of implementing control measures in concrete batching facilities. The comparative analysis contributes to understanding emission sources and supports the development of pollution control strategies in the Ready-Mix industry.

The Pollution Character Analysis and Risk Assessment for Metals in Dust and PM_(10) around Road from China

INTRODUCTION In recent years, with the gradual improvement of road construction, the rapid increase of the number of motor vehicles, vehicle emissions and the current poor vehicle performance, poor vehicle maintenance, higher emission factor and so on, air pollution caused by the traffic issues becomes the focus of people attention. The harmful substances are gradually accumulated to atmosphere particles surrounding roads due to dust particles （soil dusts, road dusts, construction dusts）, coal emissions, industrial emissions, vehicle emissions, biomass burning, secondary particles, which has a certain harmful influence to the atmosphere, soil and plants surrounding roads.

针对矿尘中PM10捕尘雾滴粒径的实验研究

为得到矿井中捕集PM10的雾滴粒径与PM10的关系,确定捕集PM10的最佳雾滴粒径的范围,通过自主搭建的尘-雾粒径耦合实验系统,使用激光粒度分析仪测量捕捉PM10前后的雾滴粒径。采用直径为1.0 mm的空心圆锥形喷嘴,压力分别为3、4、5 MPa,实验风速为1.5 m/s。结果表明:当PM10被雾滴捕集时,该雾滴粒径是粉尘粒径的6～13倍的概率为93%,8～10倍的概率为61.6%;3 MPa压力下,雾滴捕捉粉尘粒径的范围较大,压力为4、5 MPa时,捕集的粉尘大多小于7μm,喷嘴直径不变时,压力越大越有利于捕集PM10。根据实验结果拟合出3种压力下雾滴粒径与被捕粉尘粒径的函数关系式。

Seasonal size-segregated PM10 and PAH concentrations in a rural area of sugarcane agriculture versus a coastal urban area in Southeastern Florida, USA

Airborne particulate matter （PM） is of health and environmental concern not only in highly urbanized areas, but also in rural areas that are used for intensive agricultural purposes, In this study, PM size- segregated samples were collected simultaneously for 12 months in a small town （Belle Glade, Florida）, which is the center of a vast sugarcane growing area and at Delray Beach, a coastal city in Palm Beach County, Florida. During the winter sampling period, when sugarcane foliage is burned just before harvest- ing to reduce the amount of plant matter to be handled, PM10 levels were 50% or higher than otherwise measured, indicating that sugarcane harvesting and processing is a major local source for PM10. For the rest of the year, PM10 levels at both sites are similar, suggesting that ambient PM levels at both sites are impacted by the major urban centers in Southern Florida. During late July and early August, the PM10 levels at both sites were substantially elevated and revealed the typical red-brownish color of Saharan dust. This has been reported to occur frequently with suitable meteorological conditions over the Atlantic Ocean coupled with a Sahara dust storm event. During the sugarcane harvesting season at Belle Glade, the concentrations of PAHs associated with PM10 were up to 15 times higher than those measured during the summer growing season, indicating a substantially higher exposure of the rural population to these often mutagenic and carcinogenic compounds.

影响上海的一次沙尘过程WRF-Dust数值模拟

利用完全耦合大气化学模式WRF—Dust（Weather Research and Forecasting—Dust）对2011年5月1-4日影响上海地区的一次典型沙尘天气过程进行了数值模拟研究，并与观测资料进行了对比分析．结果表明：WRF—Dust模式成功模拟了此次沙尘过程的形成、发展和演变的整体特征及其影响时间及范围；较好地模拟了沙尘到达上海的时间（模式和观测均在1日11：00前后）和直接影响的结束时间（2日02：00前后），而且模式沙尘浓度与观测资料较为一致；但局部地区和部分时段的气象条件和沙尘模拟还存在一定的偏差，未能准确模拟过程后期沙尘回流对长三角沿海地区的影响．分析了导致模拟偏差的原因，并探讨了提高模式沙尘模拟能力的可能途径．

Using geoaccumulation index to study source profiles of soil dust in China

Source apportionment studies of TSP （atmospheric particulate matter with aerodynamic diameters ≤ 100 μm） and PM10 （atmospheric particulate matter with aerodynamic diameters ≤ 10 μm） have revealed that soil dust is an important source of these particulates in China. In this study, the contamination of soil dust was assessed through the use of a geoaccumulation index （Igeo）. The mass concentration profiles of 17 elements （Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Ba, and Pb） were established for urban soil dusts. Geochemical compositions of soils from 15 cities were used to represent background urban soil compositions. The results of this study indicated that a number of cities are severely polluted by particulates containing Ca, Cr, Ni, and Cu in both size fractions （TSP and PM10）. Contamination with Zn, Pb, Co, and Br was moderate to severe （Igeo 〉 2）. The Al and Fe concentrations were not high enough for them to be considered contaminants.

X-ray Diffraction of Dust Particles in Spring Beijing

X-ray diffractometry was utilized to study the mineralogical characteristics of the inhalable particles （PM10） sampled during two dust storms in Beijing city on March 18th and May 21st, 2008. We confirm, for the first time, that there stably exists ammonium chloride in the atmosphere when temperature is low. The total sulfates particles were affected by relative humidity. Both species and concentration of sulfates decreased first and then grew back by the end of each dust storm. Koninckite, a phosphate mineral never reported as particulate aerosol before, was identified. Meanwhile, our result shows that a chemical modification on dust minerals occurs during long range transportation. PM10 samples collected during the period of dust storms were dominated by crustal minerals such as quartz, illite/smectite, illite, chlorite, feldspar and calcite, and were notably higher in concentration than that in normal periods of time. The amounts of total sulfates, calcite and feldspar altered in each dust storm. It is derived from 24-hour isentropic backward trajectories that two dust events in spring 2008 originated in different sources.

Chemistry and particle size distribution of respirable coal dust in underground mines in Central Eastern Europe

Despite international efforts to limit worker exposure to coal dust,it continues to impact the health of thousands of miners across Europe.Airborne coal dust has been studied to improve risk models and its control to protect workers.Particle size distribution analyses shows that using spraying systems to suppress airborne dusts can reduce particulate matter concentrations and that coals with higher ash yields produce finer dust.There are marked chemical differences between parent coals and relatively coarse deposited dusts(up to _(500)μm,DD_(500)).Enrichments in Ca,K,Ba,Se,Pb,Cr,Mo,Ni and especially As,Sn,Cu,Zn and Sb in the finest respirable dust fractions could originate from:(i)mechanical machinery wear;(ii)variations in coal mineralogy;(iii)coal fly ash used in shotcrete,and carbonates used to reduce the risk of explosions.Unusual enrichments in Ca in mine dusts are attributed to the use of such concrete,and elevated K to raised levels of phyllosilicate mineral matter.Sulphur concentrations are higher in the parent coal than in the DD_(500),probably due to relatively lower levels of organic matter.Mass concentrations of all elements observed in this study remained below occupational exposure limits.

Assessment of Distribution and Composition of Quarry Mine Dust: Case of Pomona Stone Quarries, Harare

The study aimed at assessing the distribution and composition of dust produced at Pomona Stone Quarry mine in Harare, Zimbabwe. The source contribution to ambient PM2.5 and PM10 dust levels were quantified and their spatial distribution from the quarry to the receptor (community). The study also analysed the pH of soils around the mine, SiO2 and Al2O3 levels in quarry dust. Data was collected through direct observations, personal communications, experiments, soil and dust sampling and analyses. Dust sampling was done in January, April and August, to assess the effect of meteorological conditions on dust concentrations in two phases. Phase 1 was conducted during plant shut down (baseline measurements) while phase 2 was carried out during full plant operations (normal operating conditions), to assess the effect of quarry operations on the surrounding areas. Within the quarry production processes, crushing stage was the most dust emitting stage. Phase 1 dust results showed that both respirable (PM2.5) and inhalable (PM10) dust at all stages were below the legal limit, thus below 35 mg/m3 (respirable) and 180 mg/m3 (inhalable). Highest dust levels (209.9 mg/m3 inhalable and 69.01 mg/m3 respirable) were recorded in August, followed by April (206.9 mg/m3 inhalable and 67.52 mg/m3 respirable) then January (206.82 mg/m3 inhalable and 65.27 mg/m3 respirable). At all stages, highest dust concentrations for both parameters were recorded near the plant and decreased with increasing distance from the plant ( ranging from 209.9 mg/m3 - 19.41 mg/m3 inhalable and 69.01 mg/m3 - 14.23 mg/m3 respirable). This was attributed to the effect of particle size. August recorded the biggest area for both parameters falling within the non-permissible category, followed by April then January. The findings also revealed that the quarry dust contained higher levels of SiO2 (0.752 mg/cm3) which were 7 times higher than the recommended 0.1 mg/cm3 (NSSA). Low Al2O3 levels of 0.102 mg/cm3 were recorded and this was considered as environmentally safe. Soils were slightly acidic-alkaline and the t-test results at 95% confidence interval showed no significant difference between the results from site A and B (p = 0.526). It was concluded that quarry dust from Pomona had no significant effects on soil pH but possible health impacts on the receiving community. The study recommended that dust suppression systems such as water sprays, vegetation, air nets and enclosed production process must be implemented to curb dust emissions.

Does Dust from Arctic Mines Affect Caribou Forage?

This study explores how dust from the Ekati Diamond Mine potentially affects the availability and quality of forage on the seasonal range of the Bathurst caribou herd. Understanding the effects of dust as a source of disturbance is important because the Bathurst caribou population has declined by 93% since the middle 1980s and there are reports that caribou in general may avoid mining projects. There are several challenges for quantifying dust impacts: 1) Natural variations (e.g., topography, natural disturbance, and soil pH) may also impact forage availability and quality for caribou. To minimize their masking effect, we stratified survey sites into seven land cover classes and selected the most populous class (i.e., the dwarf shrub) for assessing the impact. 2) Within class variation (e.g., the proportion of area covered by rocks where vascular plants and lichen do not grow) can further skew the analysis. We eliminated this problem by examining only the area not covered by rocks. 3) Coarse and fine suspended particulates have different spatial coverages, chemical compositions, and pH values. Consequently, their impacts on caribou forage can be different. To distinguish their impacts, we sampled two areas: transects from the Misery Haul Road that has been in active use vs. those from a rarely used spur road outside the Misery Camp. We sampled percent vegetation cover, soil pH, and dust on leaves along these transects during the summers of 2015 and 2016. Our results indicated that the amount of dust on leaves in a zone of ~1000 m from the Misery Haul Road was 3 - 9 times than that of background sites. The zone of reduced lichen percent cover was also about 1000 m. In contrast, these road dust-induced changes in caribou forage were not observed for the dust-free transect from the spur road.

Simulation and Evaluation of Dust Emission with Polair3D-SIREAM Model over West Africa Focused on Ouagadougou (Burkina Faso)

The study of air pollution is recent in West Africa. There is a lack of data on air pollution. However, some studies conducted in West Africa show that air quality is a concern. Population growth and massive vehicles imports are contributing to the deterioration of this air quality. In this work, we present the modelling of desert aerosols using a CTM Polair3D-SIREAM. The objective is to evaluate the ability of Polair3D-SIREAM to reproduce observations of PM10 and Aerosol Optical Thicknesses (AOT). A simulation with Polair3D-SIREAM was carried out in West Africa, focused on Ouagadougou (Burkina Faso) for 2007. The model of Marticorena and Bergametti (1995), MB95, was used to estimate desert aerosols emissions. The total emission of dust modelled is 52.2 Tg. For the evaluation of PM10, the simulated averages remained within the same orders of magnitude as the observed averages. Correlations are low in all the observation sites. The other indicators are similar to those found by Schmechtig et al. (2011). Performance criteria of Boylan and Russel (2006) are met for the observation sites of Ouagadougou and Ilorin (Nigeria). For the AOTs, the correlations are significantly improved, in particular, at the sites of Ouagadougou and Ilorin. Performance criteria of Boylan are met for all observation sites. However, the performance goals are only achieved for Ouagadougou and Ilorin.

风环境视角下校园道路群落对PM_(10)的滞尘效应及优化研究

以提升秋季校园道路群落滞尘效应为目标,探索不同室外风环境与群落特征对植物滞尘能力的影响,其次采用实测与PHOENICS模拟相结合的方式,分析并评价校园室外风环境,并使用线性回归验证了实验可行性,以此为校园绿地植物群落滞尘能力的提升提供建议。以北京林业大学校园内16条结构性道路为基础进行研究,结果显示:①秋季风速对道路群落滞尘效应的影响较为显著,实测数据中道路的平均风速值为0.44时群落滞尘能力达到最强,过高或过低的风速值均会降低植物的滞尘能力;②不同结构道路群落对PM_(10)滞尘效应的强弱顺序为:乔草型>乔灌型>乔灌草型>灌草型>乔木型,且滞尘能力差异较大,可达50%;③校园室外风环境中不同道路的风速差异较大,风速偏大的道路群落里普遍缺少低层次的灌木及小乔群落,应适当增添可防风的绿化。

深圳市道路扬尘排放因子研究

本研究通过资料调研、实地调查、尘负荷测试、模型估算等方法,获取了深圳市尘负荷和PM_(10)、PM_(2.5)排放因子,为排放清单建立提供了基础数据,也为大气环境精细化治理提供了支撑。研究发现:(1)深圳市各级道路尘负荷在0.21~0.58 g/m^(2)之间,PM_(10)排放因子在0.19~0.47 g/VKT之间,PM_(2.5)排放因子在0.05~0.11 g/VKT之间,均呈“次干道<快速路<主干道<支路”趋势。(2)采用沥青作为铺设材料的道路和路面完好的道路尘负荷较小,建议采用沥青作为道路铺设材料,并强化道路养护,以减少道路尘负荷、削减道路扬尘排放。(3)不同城市之间道路尘负荷和PM_(10)、PM_(2.5)排放因子差异较为显著,有条件的城市应开展本地化测试工作,为排放清单开发提供更可靠的基础数据。

深圳市道路扬尘化学组分特征及来源研究

本研究针对深圳市34条典型道路开展了道路扬尘样品采集工作,并分析了其化学组分,建立了深圳市道路扬尘PM_(10)和PM_(2.5)成分谱,利用富集因子法、特征组分比值法等识别了深圳市道路扬尘的主要来源。结果表明:(1)深圳市道路扬尘PM_(10)和PM_(2.5)化学组分相似,均以OC、Si、Ca、Al、Fe、Ca^(2+)、EC、K和Mg等组分为主。(2)道路移动源、工业源、以SO_(2)排放为主的固定源和二次有机生成过程是深圳市道路扬尘的主要来源。(3)道路扬尘可以视为上述污染源的汇,上述排放源减排对道路扬尘减排应有一定协同作用。

石家庄冬季道路积尘PM_2.5与PM_10碳组分污染特征分析

为探讨石家庄市冬季道路积尘中PM_2.5与PM_10的碳组分污染特征和来源,利用移动式采样法对市区不同类型铺装道路积尘进行收集,用热光碳分析仪测定样品中有机碳(OC)和元素碳(EC)的含量并分析其特征.结果表明,OC、EC在PM_2.5中的平均质量浓度为166.54 mg·g^(-1)、25.35 mg·g^(-1),在PM_10中的平均质量浓度为118.31 mg·g^(-1)、20.3 mg·g^(-1),总碳(TC)占PM_2.5中百分比为19.2%,占PM_1013.9%,表明碳组分更容易富集到细粒径颗粒物上;相关性分析表明OC、EC来源大致相同;8个碳组分中OC3的百分含量最高,OC4次之,EC3最低;主成分分析及OC、EC相关分析结果表明冬季道路积尘中的碳主要来自于机动车尾气排放和大气降尘中的燃煤成分.

风速对人为扬尘源PM_(10)排放浓度和强度的影响

人为扬尘源排放模型很少考虑风速对排放的影响,为了解人为扬尘源排放浓度及排放强度与风速的关系,以施工扬尘和道路扬尘为典型人为扬尘源,通过现场实测研究了风速对扬尘源附近大气环境中扬尘排放浓度、排放强度的影响。结果表明,扬尘源附近大气环境中因扬尘造成的PM10（可吸入颗粒物）排放浓度随风速的增加先降后升，本研究中最低浓度值所对应的2．2m高度处的风速v（Cmin）为1．0～2．0m／s；扬尘排放强度随风速的增加逐渐升高，风速〈v（Cmin）时，排放强度随风速增加增幅较小，风速超过v（Cmin）后，排放强度迅速增大。将人为扬尘分为机械力扬尘和风蚀扬尘，进行了机制探讨，理论结果与现场观测结果是吻合的。

北京市交通扬尘对大气环境质量的影响

利用中尺度气象模式ARPS与空气质量模式Models-3/CMAQ的耦合模式,模拟2002年4个季节代表月份(1月、4月、8月和10月)北京市PM10浓度的时空分布。与监测数据对比分析表明,该耦合模式有很好的可靠性。设计了2种污染源情景方案,分析了北京市2002年4个季节代表月份交通扬尘对市区大气PM10的影响。结果表明,在4个代表月中,交通扬尘对北京市PM10的逐时贡献率波动较大,最高可达33%,最低为3%;交通扬尘对北京市大气PM10影响显著,4个月平均贡献率分别为16.73%、12.92%、18.56%和18.17%,平均贡献浓度分别为27.61μg/m3、32.80μg/m3、25.20μg/m3和24.40μg/m3。此外,依据模拟结果,结合交通扬尘污染特征与治理现状,提出了北京市交通扬尘的初步治理方案。

泰州市区空气重金属污染的多重监测研究

近年来,我国频繁发生的雾霾事件引起了人们对城市空气污染的广泛关注,大气颗粒物中含有的重金属与人类呼吸系统疾病发病率以及呼吸系统的损伤具有一定的相关性。笔者对泰州市区大气颗粒物PM2.5(颗粒物直径小于2.5μm)和PM10(颗粒物直径小于10μm)、道路灰尘、活藓和藓袋中Cd、Cr、Cu、Pb、Ni、Zn的含量与污染特征进行了分析。结果表明,粒径最小的PM2.5中重金属浓度最高,可以作为空气重金属污染分析的最佳监测对象;活藓法测得的数据与PM10和道路灰尘测定值相接近,具有一定可靠性。污染指数分析结果表明,现阶段泰州市区Cd、Cu、Zn污染较严重,分别达到了土壤背景值的18.86、3.54和3.15倍,其他重金属污染不严重。