Identify the contribution of vehicle non-exhaust emissions: a single particle aerosol mass spectrometer test case at typical road environment

● A single particle observation was conducted in a high traffic flow road environment. ● Major particle types were vehicle exhausts, coal burning, and biomass burning. ● Contribution of non-exhaust emissions was calculated via PMF. ● Proportion of non-exhaust emissions can reach 10.1 % at road environment. A single particle aerosol mass spectrometer (SPAMS) was used to accurately quantify the contribution of vehicle non-exhaust emissions to particulate matter at typical road environment. The PM_2.5, black carbon, meteorological parameters and traffic flow were recorded during the test period. The daily trend for traffic flow and speed on TEDA Street showed obvious “M” and “W” characteristics. 6.3 million particles were captured via the SPAMS, including 1.3 million particles with positive and negative spectral map information. Heavy Metal, High molecular Organic Carbon, Organic Carbon, Mixed Carbon, Elemental Carbon, Rich Potassium, Levo-rotation Glucose, Rich Na, SiO₃ and other categories were analyzed. The particle number concentration measured by SPAMS showed a good linear correlation with the mass concentrations of PM_2.5 and BC, which indicates that the particulate matter captured by the SPAMS reflects the pollution level of fine particulate matter. EC, ECOC, OC, HM and crustal dust components were found to show high values from 7:00–9:00 AM, showing that these chemical components are directly or indirectly related to vehicle emissions. Based on the PMF model, 7 major factors are resolved. The relative contributions of each factor were determined: vehicle exhaust emission (44.8 %), coal-fired source (14.5 %), biomass combustion (12.2 %), crustal dust (9.4 %), ship emission (9.0 %), tires wear (6.6 %) and brake pads wear (3.5 %). The results show that the contribution of vehicle non-exhaust to particulate matter at roadside environment is approximately 10.1 %. Vehicle non-exhaust emissions are the focus of future research in the vehicle pollutant emission control field.     

VMT reduction and potential environmental effects with a tradable credits scheme: a simulation case study of Great Britain

We investigate the influence of a tradable credits scheme (TCS) on travel demand and vehicle emissions, based on the vehicle miles travelled (VMT). With a microeconomic quantitative analysis scheme, a constant elasticity of substitution (CES) function is used as an approach to model the annual mileage for different travel purposes. An illustration is given for the effects of a TCS on emission mitigation based on historical data for Great Britain. A scenario analysis demonstrates that a TCS can achieve a target for reducing the number of private trips. Besides a movement of trips from the private car mode to public modes, there is also some trip restraint, with individuals choosing not to take some trips. Compared with Fowkes et al.’s research on road pricing in London, the research illustrates that a TCS can be designed to have similar effects to a road pricing scheme. We also demonstrate that a TCS could bring emission changes arising from changes in VMT.     

A Bayesian hierarchical model for assessing the impact of human activity on nitrogen dioxide concentrations in Europe

Ambient concentrations of many pollutants are associated with emissions due to human activity, such as road transport and other combustion sources. In this paper we consider air pollution as a multi-level phenomenon on a continental scale within a Bayesian hierarchical model. We examine different scales of variation in pollution concentrations ranging from large scale transboundary effects to more localised effects which are directly related to human activity. Specifically, in the first stage of the model, we isolate underlying patterns in pollution concentrations due to global factors such as underlying climate and topography, which are modelled together with spatial structure. At this stage measurements from monitoring sites located within rural areas are used which, as far as possible, are chosen to reflect background concentrations. Having isolated these global effects, in the second stage we assess the effects of human activity on pollution in urban areas. The proposed model was applied to concentrations of nitrogen dioxide measured throughout the EU for which significant increases are found to be associated with human activity in urban areas. The approach proposed here provides valuable information that could be used in performing health impact assessments and to inform policy.     

Emission factors and chemical characterisation of fine particulate emissions from modern and old residential biomass heating systems determined for typical load cycles

It is already well known that there are significant differences regarding the emissions, especially particulate matter (PM) emissions, of old and modern as well as automatically and not automatically controlled biomass based residential heating systems. This concerns their magnitude as well as their chemical composition. In order to investigate emission factors for particulate emissions and the chemical compositions of the PM emissions over typical whole day operation cycles, a project on the determination and characterisation of PM emissions from the most relevant small-scale biomass combustion systems was performed at the BIOENERGY 2020+ GmbH, Graz, Austria, in cooperation with the Institute for Process and Particle Engineering, Graz University of Technology. The project was based on test stand measurements, during which relevant operation parameters (gaseous emissions, boiler load, flue gas temperature, combustion chamber temperature etc.) as well as PM emissions have been measured and PM samples have been taken and forwarded to chemical analyses. Firstly, typical whole day operation cycles for residential biomass combustion systems were specified for the test runs. Thereby automatically fed and automatically controlled boilers, manually fed and automatically controlled boilers as well as manually fed stoves were distinguished. The results show a clear correlation between the gaseous emissions (CO and OGC) and the PM₁ emissions. It is indicated that modern biomass combustion systems emit significantly less gaseous and PM emissions than older technologies (up to a factor of 100). Moreover, automatically fed systems emit much less gaseous and PM emissions than manually fed batch-combustion systems. PM emissions from modern and automatically controlled systems mainly consist of alkaline metal salts, while organic aerosols and soot dominate the composition of aerosols from old and not automatically controlled systems. As an important result comprehensive data concerning gaseous and PM emissions of different old and modern biomass combustion systems over whole day operation cycles are now available. Derived from these data, correlations between burnout quality, particulate emissions as well as particle composition of the PM emissions can be deduced.     

Impacts of inter-sectoral trade on carbon emissions—a case of China in 2007

With the increase in international trade, more attention has been given to quantifying the impacts of international trade on energy use and carbon emissions. Input-output analysis is a suitable tool for assessing resources or pollutants embodied in trade and it has become a critical tool for performing such analysis. This study estimated the national and sectoral carbon emissions embodied in Chinese international trade using the latest available China input-output table of 2007. The results showed that a significant exporting behavior of embodied carbon emissions existed in China??s trade. Over 1/3 of the emissions in Chinese domestic production processes were generated for exports in 2007. The net balance of emissions embodied in exports and imports accounted for nearly 30% of China??s domestic emissions, which means that any policy made to increase the exports would result in a significant growth of China??s domestic emissions. Since over half of China??s export trade is processing trade, the re-exported emissions could not be overlooked; otherwise, it would hard to capture the actual emissions generated abroad to obtain China??s domestic consumption. The enlargement of export scale is a primary driven factor to the rapid growth of China??s exported emissions. It is necessary for China to adjust its economic and industrial structure to reduce the dependence of economic growth on the export trade. However, when adjusting industry structures or making policies on carbon emission reduction, it will be more reasonable to consider the relationship between production and consumption, rather than just focus on the emission values of sectors?? direct production, as a large part of carbon emissions emitted by the principal direct polluters were generated to obtain the products which were required by other sectors.     

Emissions- und Immissionsprognosen für den Straßenverkehr in Deutschland

The use of such threshold values, which are valid today and will be valid in the future, for waste gas emissions from motor vehicles will continuously serve to further limit the amounts of emissions from the motorized traffic in Germany, even though it must be assumed that an ever increasing amount of mileage will be observed. Following the reduction in emissions which have been calculated, and the estimated improvements to be seen in this area, important goals in atmospheric quality should be achieved in the future. Especially the risk of cancer associated with motorvehicle traffic will drop appreciably below the target goals. The most important problem of the air pollution stemming from traffic emissions, however, seems to be the fine dusts. A reduction in the quantity of these substances may possibly be related to the emissions of nitric oxides and also of NMVOCs. The efficient reduction of the climatically-relevant emissions attributed to motor-vehicle traffic is a great challenge to the fields of technology, fuel supply and user behavior patterns. These factors will therefore represent an important part of the long-term environmental discussions.     

Response of organic aerosol characteristics to emission reduction in Yangtze River Delta region

● The emission reduction causes significant change in organic aerosol composition. ● The atmospheric oxidizing capacity improved during emission reduction. ● The mixed oxygenated organic aerosol contributed higher during emission reduction. Organic aerosol (OA) is a major component of atmospheric particulate matter (PM) with complex composition and formation processes influenced by various factors. Emission reduction can alter both precursors and oxidants which further affects secondary OA formation. Here we provide an observational analysis of secondary OA (SOA) variation properties in Yangtze River Delta (YRD) of eastern China in response to large scale of emission reduction during Chinese New Year (CNY) holidays from 2015 to 2020, and the COVID-19 pandemic period from January to March, 2020. We found a 17% increase of SOA proportion during the COVID lockdown. The relative enrichment of SOA is also found during multi-year CNY holidays with dramatic reduction of anthropogenic emissions. Two types of oxygenated OA (OOA) influenced by mixed emissions and SOA formation were found to be the dominant components during the lockdown in YRD region. Our results highlight that these emission-reduction-induced changes in organic aerosol need to be considered in the future to optimize air pollution control measures.     

A dispersion model for traffic produced turbulence in a two-way traffic scenario

Low wind speed conditions are often associated with poor air quality in urban areas, especially near roadways. Predictions of pollutant concentration under such conditions, i.e. low wind-speeds and near road locations, are, however, complicated by the role of traffic produced turbulence (TPT) on pollutant mixing and dilution. Existing dispersion models consider the effect of TPT on pollutant concentrations near roadways, accounting for parameters such as vehicle intensity, vehicle speeds, etc, but do not explicitly account for the contribution of two-way traffic interaction on the pollutant dispersion parameter. The turbulent kinetic energy (TKE) resulting from a two-way traffic condition will be higher than that with a one-way traffic pattern. Here, we obtain a simple formulation for TKE under a two-way traffic pattern from the balance of production and dissipation of turbulence. Considering the vorticity generated by the two-way traffic and determining the equivalent drag coefficient, an expression for TKE due to the two-way traffic interaction was obtained for three different traffic density regimes: light, intermediate, and heavy. The model predictions are validated by comparison with published data from a field study. An improved parameterization of the TPT considering the two-way traffic interaction effect is seen to significantly improve predictions of near roadway pollutant concentrations.     

A cost-effectiveness analysis of alternative air quality control strategies

A number of linear programming models purport to minimize the costs of emission control to achieve ambient air quality standards. Many of the simulations incorporate the simplifying assumption that improvements in ambient air quality are proportional to reductions in regional emissions. This approach minimizes the cost of mass emission reduction, but not the cost to achieve a prescribed ambient air quality. The costs of this emissions least-cost strategy are compared to an ambient least-cost strategy which does achieve prescribed ambient air quality at minimum cost. The cost saving achieved by this strategy relative to the emissions least-cost strategy is as much as 50670. In addition, both are compared to a strategy typical of those currently used by the states, which is found to be as much as ten times as expensive as the ambient least-cost strategy.     

中国燃煤电厂碳排放量计算及分析

人类活动造成的温室气体排放已经对自然生态造成了巨大的影响。如果无法有效解决气候变化问题,到2030年将有超过1亿人因此而失去生命,且全球经济增长将削减3.2%。有效地控制和减少温室气体的排放是人类急需解决的问题。目前中国温室气体排放总量已经超越美国成为全球第一大温室气体排放国,中国的能源结构决定了中国燃煤发电是中国CO2主要排放源之一,因此实现燃煤发电碳减排对降低中国碳排放总量,减少温室气体排放具有重要意义。准确地计算燃煤电厂产生的碳排放量是进行碳排放权交易、低碳火电厂在经济上具有可行性,最终实现燃煤电厂碳减排的前提条件之一。本研究根据世界资源研究所提供的计算工具首先界定了本研究对于碳排放计算的范围,其次阐述了不同电厂应针对其使用的燃煤进行工业分析的精细化程度不同而采用不同的计算方法,最后对两组不同机组类型的中国火电厂进行了碳排放量计算和对比分析。根据以上分析得出了大容量、高参数的燃煤发电机组相比小容量发电机组不仅能提高能源利用效率,同时也能相对减少因生产电能而产生的CO2排放。其次,燃煤电厂CO2排放中煤炭固定燃烧占有绝对比例,脱硫及外购电力所占比例较小,但排放的绝对总量并不小。再次,由于大容量、高参数机组与小容量发电机组相比在生产单位电能所消耗的燃煤量更少、其排放的废弃中的CO2浓度相对较高,应此更适合安装碳捕捉系统,有助于提高捕捉效率,降低捕捉CO2的成本。因此,建议在未来建设碳捕捉系统时应优先选择大容量、高参数机组。本研究的创新点在于在上述研究的基础上考虑单个燃煤电厂的煤质、考虑电厂脱硫、外购电力的因素,根据电厂对煤质不同程度的工业分析采用不同的计算方法,目的在于更?     

Biomonitoring verkehrsbedingter Platin-Immissionen

Traffic related platinum deposits on, or near to, the roads. Platinum accumulation was studied using the method of standardised culture of grass (Lolium multiflorum) at locations with different traffic exposure in the region of Munich. Grass cultures from 6 locations with high traffic exposure, and 3 reference locations far away from traffic emissions, were analysed in 1992 and 1993. The results show a good indication of the platinum emissions byLolium multiflorum. The platinum concentrations rose with the increasing traffic. They diminished with growing distance from the verge of the road. The highest average platinum concentrations were measured at locations close to highly frequented urban roads, in the range 0.8 to 2.9 μg/kg dm. The average platinum concentration at locations far from emissions was found in the range of 0.17 to 0.51 μg/kg dm in 1992 and 1993. The good correlation between the platinum concentrations in grass cultures and the concentrations of other traffic-related elements, like antimony, chromium and lead, verifies the dependence of platinum accumulation from traffic.     

区域及全球尺度的NPP过程模型和NPP对全球变化的响应

植被净第一性生产力（NPP）不仅是表征植被活动和生态过程的关键参数,而且是判定生态系统碳汇和反映生态系统对全球变化响应的主要因子。当前,模型模拟成为大尺度NPP研究的主要手段,而在众多NPP估算模型中,过程模型逐渐趋于主导地位。虽然目前有关NPP的研究有很多,但还没有关注于大尺度上应用的过程模型及其模拟的NPP对全球变化的响应。因此本文主要侧重于 NPP 过程模型在区域及全球尺度上的应用,具体包含以下内容,①进一步将区域及全球尺度的NPP过程模型分为静态植被模型和动态植被模型。②阐明这些模型间存在的区别与联系。③归纳出NPP过程模型在区域及全球尺度上应用的3大挑战：时空尺度转换、多源数据的获取与融合以及模型模拟结果的验证与评价,并根据其解决方案总结出通用的模型应用框架。④从气候变化、大气成分变化和土地利用/土地覆盖变化3个方面探讨NPP对全球变化的响应机制,以期找到NPP变化的规律与模式。最后根据NPP模型的发展对未来区域及全球尺度的NPP过程模型进行展望,认为未来模型的综合性将更高,机理性也将更强,同时与全球变化研究结合得更加紧密,且基于多个已有模型的混合模型也是未来NPP模型发展的一个重要方向。此外,本文认为对NPP模拟结果的尺度效应研究也是未来NPP研究的热点之一。     

Artificial neural network approach for modelling nitrogen dioxide dispersion from vehicular exhaust emissions

Artificial neural networks (ANNs) are useful alternative techniques in modelling the complex vehicular exhaust emission (VEE) dispersion phenomena. This paper describes a step-by-step procedure to model the nitrogen dioxide (NO₂) dispersion phenomena using the ANN technique. The ANN-based NO₂ models are developed at two air-quality-control regions (AQCRs), one, representing, a traffic intersection (AQCR1) and the other, an arterial road (AQCR2) in the Delhi city. The models are unique in the sense that they are developed for ‘heterogeneous¹’ traffic conditions and tropical meteorology. The inputs to the model consist of 10 meteorological and 6 traffic characteristic variables. Two-year data, from 1 January 1997 to 31 December 1998 has been used for model training and data from 1 January to 31 December 1999, for model testing and evaluation purposes. The results show satisfactory performance of the ANN-based NO₂ models on the evaluation data set at both the AQCRs (d = 0.76 for AQCR1, and d = 0. 59 for AQCR2).     

Metacommunity influences on community richness at multiple spatial scales: a microcosm experiment

Large-scale processes are known to be important for patterns of species richness, yet the ways in which local and larger scale processes interact is not clear. I used metacommunities consisting of five interconnected microbial aquatic communities to examine the manner in which processes at different scales affect local and metacommunity richness. Specifically, I manipulated the potential dispersal rate, whether dispersal was localized or global, and variation in initial community composition. A repeated-measures ANOVA showed that a low dispersal rate and intermediate distance dispersal enhanced local richness. Initial assembly variation had no effect on local richness, while a lack of dispersal or global dispersal reduced local richness. At the metacommunity scale, richness was enhanced throughout the time course of the experiment by initial compositional variation and was reduced by high or global dispersal. The effects of dispersal were contingent on the presence of initial compositional variation. The treatments also affected individual species occupancy patterns, with some benefiting from large-scale processes and others being adversely impacted. These results indicate that the effects of dispersal on species richness have a complex relationship with scale and are not solely divisible into "regional" vs. "local" scales. Finally, predictions of the manner in which dispersal rate structures communities appear dependent upon species compositional variation among communities.     

The value of virtual conferencing for ecology and conservation

The objectives of conservation science and dissemination of its research create a paradox: Conservation is about preserving the environment, yet scientists spread this message at conferences with heavy carbon footprints. Ecology and conservation science depend on global knowledge exchange—getting the best science to the places it is most needed. However, conference attendance from developed countries typically outweighs that from developing countries that are biodiversity and conservation hotspots. If any branch of science should be trying to maximize participation while minimizing carbon emissions, it is conservation. Virtual conferencing is common in other disciplines, such as education and humanities, but it is surprisingly underused in ecology and conservation. Adopting virtual conferencing entails a number of challenges, including logistics and unified acceptance, which we argue can be overcome through planning and technology. We examined 4 conference models: a pure‐virtual model and 3 hybrid hub‐and‐node models, where hubs stream content to local nodes. These models collectively aim to mitigate the logistical and administrative challenges of global knowledge transfer. Embracing virtual conferencing addresses 2 essential prerequisites of modern conferences: lowering carbon emissions and increasing accessibility for remote, time‐ and resource‐poor researchers, particularly those from developing countries.     

城市地表汞含量及释放通量影响因素分析

测定了长春市不同类型地表汞含量及其释放通量，分析了地表汞释放通量的影响因素。研究结果表明，不同地表土样的汞含量存在很大的差异；煤炭堆放地和沥青地地表汞含量较高，应引起足够的重视。地表汞释放通量受地表汞含量、地表类型、降水、太阳辐射等因素的影响。降水期间或降水后期地表汞释放通量明显增加。可见，地表汞释放是一个动态过程，随时间和空间而变化。     

基于生态保护的道路规划策略

分析了路段与景观两个尺度上的道路生态环境影响,结合当今景观生态学、道路生态学的研究成果,系统论述了与道路交通规划建设相关的生态策略：（1）在区域尺度上,依据生态敏感度规划路网密度、保持大型自然空间的生态完整性、提倡非生态敏感地段的交通集中、增加路网的区域水平渗透性;（2）在路段规模上,自然空间的生境避让、保持重要地段的自然连续性、打破交通生态瓶颈、减少道路交通的环境影响、补偿道路建设的生态影响等。这些策略旨在为可持续道路交通提供基于生态合理性的规划原则与方法。     

Aeolian erosion of storage piles yards: contribution of the surrounding areas

Dust emissions from stockpiles surfaces are often estimated applying mathematical models such as the widely used model proposed by the USEPA. It employs specific emission factors, which are based on the fluid flow patterns over the near surface. But, some of the emitted dust particles settle downstream the pile and can usually be re-emitted which creates a secondary source. The emission from the ground surface around a pile is actually not accounted for by the USEPA model but the method, based on the wind exposure and a reconstruction from different sources defined by the same wind exposure, is relevant. This work aims to quantify the contribution of dust re-emission from the areas surrounding the piles in the total emission of an open storage yard. Three angles of incidence of the incoming wind flow are investigated ( $30^{\circ }, 60^{\circ }$ and $90^{\circ }$ ). Results of friction velocity from numerical modelling of fluid dynamics were used in the USEPA model to determine dust emission. It was found that as the wind velocity increases, the contribution of particles re-emission from the ground area around the pile in the total emission also increases. The dust emission from the pile surface is higher for piles oriented $30^{\circ }$ to the wind direction. On the other hand, considering the ground area around the pile, the $60^{\circ }$ configuration is responsible for higher emission rates (up to 67 %). The global emissions assumed a minimum value for the piles oriented perpendicular to the wind direction for all wind velocity investigated.