Theodoros Grigoratos

PM10 composition during an intense Saharan dust transport event over Athens (Greece)

The influence of Saharan dust on the air quality of Southern European big cities became a priority during the last decade. The present study reports results on PM(10) monitored at an urban site at 14 m above ground level during an intense Saharan dust transport event. The elemental composition was determined by Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF) for 12 elements: Si, Al, Fe, K, Ca, Mg, Ti, S, Ni, Cu, Zn and Mn. PM(10) concentrations exceeded the EU limit (50 μg/m(3)) several times during the sampling period. Simultaneous maxima have been observed for the elements of crustal origin. The concentrations of all the elements presented a common maximum, corresponding to the date where the atmosphere was heavily charged with particulate matter permanently for an interval of about 10h. Sulfur and heavy metal concentrations were also associated to local emissions. Mineral dust represented the largest fraction of PM(10) reaching 79%. Seven days back trajectories have shown that the air masses arriving over Athens, originated from Western Sahara. Scanning Electron Microscopy coupled with Energy Dispersive X-ray analysis (SEM-EDX) revealed that particle agglomerates were abundant, most of them having sizes <2 μm. Aluminosilicates were predominant in dust particles also rich in calcium which was distributed between calcite, dolomite, gypsum and Ca-Si particles. These results were consistent with the origin of the dust particles and the elemental composition results. Sulfur and heavy metals were associated to very fine particles <1 μm.

Chemical composition and mass closure of ambient coarse particles at traffic and urban-background sites in Thessaloniki, Greece

Concentrations and chemical composition of the coarse particle fraction (PMc) were investigated at two urban sites in the city of Thessaloniki, Greece, through concurrent sampling of PM10 and PM2.5 during the warm and the cold months of the year. PMc levels at the urban-traffic site (UT) were among the highest found in literature worldwide exhibiting higher values in the cold period. PMc levels at the urban-background site (UB) were significantly lower exhibiting a reverse seasonal trend. Concentration levels of minerals and most trace metals were also higher at the UT site suggesting a stronger impact from traffic-related sources (road dust resuspension, brake and tire abrasion, road wear). According to the chemical mass closure obtained, minerals (oxides of Si, Al, Ca, Mg, Fe, Ti, and K) dominated the PMc profile, regardless of the site and the period, with organic matter and secondary inorganic aerosols (mainly nitrate) also contributing considerably to the PMc mass, particularly in the warm period. The influence of wind speed to dilution and/or resuspension of coarse particles was investigated. The source of origin of coarse particles was also investigated using surface wind data and atmospheric back-trajectory modeling. Finally, the contribution of resuspension to PMc levels was estimated for air quality management perspectives.

Effect of a DPF and Low Sulfur Lube Oil on PM Physicochemical Characteristics from a Euro 4 Light Duty Diesel Vehicle

This paper studies the effect of a Catalyzed Diesel Particle Filter (CDPF) on the emission profile of a Euro 4 diesel vehicle operated on low sulfur fuel and lubrication oil. The vehicle was tested in its original configuration and with the CDPF retrofitted in place of its main underbody catalyst. Experiments included steady state tests, the certification cycle and real-world high speed transient driving conditions. Measurements included total particle mass collected on Teflon-coated filters, total particle number measured by a condensation particle counter, size distributions determined by a Scanning Mobility Particle Sizer and chemical analysis of the mass collected for elemental and organic carbon, ions, PAHs, and trace elements. Results showed that the vehicle complies with the Euro 4 emission limits when tested over the type-approval NEDC, but it emits more nitrogen oxides and, in some cases, more particulate matter when tested over real-world test cycles. The CDPF reduces PM mass emission up to 90-95% and particle number by 2-3 orders of magnitude. However, nucleation of volatile species may occur under specific conditions of the engine exhaust dilution and sampling system and may mask this reduction. Emissions of chemical elements, elemental and organic carbon were also substantially reduced by the CDPF, while moderate reductions of ionic species and PAHs were observed.

Estimating the CO 2 Emissions Reduction Potential of Various Technologies in European Trucks Using VECTO Simulator

Heavy-duty vehicles (HDVs) account for some 5% of t he EU’s total greenhouse gas emissions. They present a variety of possible configurations that are deployed depending on the i ntended use. This variety makes the quantification of their CO 2 emissions and fuel consumption difficult. For this reason, the Europea n Commission has adopted a simulation-based approach for the certifi ca on of CO2 emissions and fuel consumption of HDVs in Europe; t he VECTO simulation software has been developed as the offic ial tool for the purpose. The current study investigates the impact of various technologies on the CO 2 emissions of European trucks through vehicle simulations performed in VECTO. The chosen vehicles represent average 2015 vehicles and comprised of tw o rigid trucks (Class 2 and 4) and a tractor-trailer (Class 5), wh ich were simulated under their reference configurations and official d riving cycles. The effects of aerodynamics, auxiliary systems, curb-we ight, tyre rolling resistance, engine internal losses, and engine and gearbox efficiency were investigated. Factors exhibited a varying redu ction potential that depended on the vehicle category and the driving cy cle. Results indicate where focus should be given for improving the energy performance of trucks in view of the Commission’s f uture efforts to propose CO2 reduction targets for HDVs. Introduction Road CO2 emissions in the European Union account for about 24% [1] of the region’s total emissions a quarter of wh ich is attributed to heavy-duty vehicles, a term attributed to trucks an d buses [2,3]. Committing to climate change mitigation, the Europe an Commission has set a target to reduce road emissions by 60% by 2050 with respect to 1990 levels [4]. For this reason, in the field of road transportation, it has set mandatory CO 2 targets for passenger and light commercial vehicles and is currently working on a strategy to reduce emissions in heavy-duty vehicles [3]. In con trast to light-duty vehicles, heavy-duty vehicles present a large varie ty of configurations that are tailored to the needs of th e desired application. It is therefore difficult to assess CO 2 emissions using chassis dynamometer measurements as a basis for monitoring compliance of heavy-duty vehicles. In heavy-duty vehicles the pos sible number of configurations could be expected to increase as the re is a wide variety of fuel improving/CO2 reducing technologies [5] which could be potentially deployed in the future. Any policy init iatives should foster the introduction of such technologies and address f actors that may slow down the uptake of fuel-efficient innovations. The European Commission is addressing these issues by developing the Vehicle Energy Consumption Calculation Tool (VECTO), which will be used to calculate fuel consumption and CO 2 emissions of heavy-duty vehicles through vehicle simulation. The aim of the tool is to provide a standardized method to calculate fuel consumption and CO2 emissions by modelling the operation of vehicles ov er realistic driving cycles [6]. The European Commission has chosen to develop a met hodology that will be based on vehicle simulation in order to eve ntually cover all the possible vehicle configurations in an effective way [7] and allow the calculation of vehicle fuel consumption in a wa y that realistically reflects their real world performance. Additionally , this approach enables a standardized CO 2 emissions estimation that permits comparison between different vehicle configurations . To achieve this, two issues had to be addressed: first, the developm ent of the software that could effectively simulate fuel consumption an d second, the development of a standardized methodology for certi fying individual components and setting representative reference val ues for components that will not be measured (e.g. standard bodies). The first task is addressed with the development of VECTO, wh ich will be described in more detail in the following paragraph s, while a group of experts consisting of the JRC, DG Clima, vehicle ma nuf cturers and external consultants, is focusing on the second tas k [8]. Finally, a series of operating cycles, reflecting the differen t usages of vehicles in real world operation have been developed in coll ab ration with vehicle manufacturers, which are attributed the ter m mission profiles. Each mission profile describes a representative dri ving scenario and reference vehicle type and configuration. This work is described in the technical annex of the developing legislation with newer updates published by the European Commission on regular int e vals [9]. The mission profiles correspond to typical transpor tation scenarios and include a distance based driving cycle and road grade. The available mission profiles for trucks are the follo wing [10]: • Urban delivery represents an urban route with low average speed, increased number of stop events and stop tim e share. • Regional delivery represents an inter-urban route with portions of urban and highway driving. • Long haul represents a transport application for long distan ces that consists mostly of highway driving. • Construction represents the speed and route profile of a vehicl e that is deployed in a construction site. • Municipal utility represents the mission profile in an urban route for refuse trucks.