The Orot Rabin power plant is a 2,590 MW coal-fired power plant located along the Mediterranean coast north of Tel Aviv.Close by to the east is the city of Hadera.Due to the predominant east-west wind patterns, both Hadera and the nearby communities may be impacted by stack emissions from the power plant.In addition, on-site storage of coal and coal residue can be a source of fugitive PM emissions.To determine the sources contributing to elevated PM10 levels in the region, a source apportionment study was performed at two locations (Hephziba and Pardes-Channa) during August/October 2017.We applied a microscopic chemical imaging (MCI) methodology based on particle fluorescence to determine PM source contributions in near-real time (GreenVision Systems, Ltd., Tel Aviv, "GVS").For the Hephziba monitoring site, located closest to the power plant and adjacent to a major highway, the major emissions sources were mobile sources (29.8%) and coal power plant emissions (29.1%).In addition, fugitive coal and coal residue were estimated to contribute 11.5% of the observed PM10.At the Pardes-Channa site, located further inland and in a more residential area, contributors included mobile sources (38.6%),coal power plant emissions (19.3%), and fugitive coal and coal residue (2.7%).These results indicate the significant impact of the power plant on observed PM10 in the region, with the nearby site also experiencing a major contribution from fugitive emissions from the facility.

The Lake Tahoe Basin is located on the California-Nevada border and occasionally experiences elevated levels of ozone (O-3) exceeding the California Air Resources Board ambient air quality standard (8-h average). Previous studies indicate that both the local generation and long-range transport from out-of-basin sources are important in contributing to O-3 exceedances, but little is known about the impact of regional meteorology on O-3 source regions. To develop a better understanding of the factors affecting O-3 levels and sources in the Lake Tahoe Basin, a comprehensive field study was performed in the summer of 2010. Included in this effort was a meteorological analysis addressing potential regional meteorological influences leading to periods of elevated levels of O-3. Three approaches were used to conduct the analysis: (1) regional atmospheric pressure difference (i.e., the Washoe Zephyr) to access potential transport, (2) back trajectory modeling using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to determine where the air masses originated and, (3) composite soundings to evaluate in-Basin atmospheric influences. These analyses indicate the Washoe Zephyr did not strongly impact O-3 levels; however, higher O-3 levels were found to correspond with both a more southerly wind component and a dip in dew point temperature around 400 hPa. The results also indicate that if transport does occur, it is more likely to come from the San Joaquin Valley and move to the southern part of the Basin, rather than originating in the large cities to the west (i.e., Sacramento and San Francisco).

Surface ozone (O-3) concentrations were measured in and around the Lake Tahoe Basin using both active monitors (2010) and passive samplers (2002, 2010). The 2010 data from active monitors indicate average summertime diurnal maxima of approximately 50-55 ppb. Some site-to-site variability is observed within the Basin during the well-mixed hours of 10:00 to 17:00 PST, but large differences between different sites are observed in the late evening and pre-dawn hours. The observed trends correlate most strongly with elevation, topography, and surface vegetation. High elevation sites with steeply sloped topography and drier ground cover experience elevated O-3 concentrations throughout the night because they maintain good access to downward mixing of O-3-rich air from aloft with smaller losses due to dry deposition. Low elevation sites with flat topography and more dense surface vegetation experience low O-3 concentrations in the pre-dawn hours because of greatly reduced downward mixing coupled with enhanced O-3 removal via efficient dry deposition. Additionally, very high average O-3 concentrations were measured with passive samplers in the middle of the Lake in 2010. This latter result likely reflects diminished dry deposition to the surface of the Lake. High elevation Tahoe Basin sites with exposure to nocturnal O-3-rich air from aloft experience daily maxima of 8-h average O-3 concentrations that are frequently higher than concurrent maxima from the polluted upwind comparison sites of Sacramento, Folsom, and Placerville. Wind rose analyses of archived NAM 12 km meteorological data for the summer of 2010 suggest that some of the sampling sites situated near the shoreline may have experienced onshore "lake breezes" during daytime hours and/or off-shore "land breezes" during the night. Back-trajectory analysis with the HYSPLIT model suggests that much of the ozone measured at Lake Tahoe results from the transport of "polluted background" air into the Basin from upwind pollution source regions. Calculation of ozone exposure indices indicates that the two most polluted sites sampled by active monitors in 2010 the highest Genoa Peak site, located on the eastern side of the Lake at an elevation of 2734 m above sea level, and Angora Lookout, located to the south southwest (SSW) of the Lake at an elevation of 2218 m above sea level likely experienced some phytotoxic impacts, while the other Tahoe Basin locations received lower ozone exposures. (C) 2015 Elsevier Ltd. All rights reserved.

Life-cycle assessments (LCA) of biodistillate fuels are becoming increasingly important for policy decisions regarding alternative fuels. However, due to the dataintensive and assumptive nature of LCAs, rarely do two different studies produce comparable results. To add to the complexity, effects of indirect land use changes are now being incorporated into LCA models. This development is influencing policy decisions and generating much controversy.A literature survey of 55 different LCA studies of biodistillate fuels was conducted. The comparison of energy requirements and global warming potential (GWP) impacts of these studies help to illustrate which data inputs and assumptions most strongly affect the results, and wherein the major discrepancies lie.Life-cycle energy results are typically reported as energy return (ER), meaning the heating value of the biofuel divided by the total fossil energy inputs to produce the fuels. Most studies report significantly higher ER values for biodistillates (both biodiesel and renewable diesel) compared to conventional diesel fuel. Similarly, most LCA studies show significant GWP reductions for biodistillates compared to conventional diesel. However, due to lack of consistency in LCA approaches and assumptions, considerable uncertainty still exists regarding the accuracy of most LCA results.

Diesel vehicles are significant sources of NOx and PM emissions, and to a lesser extent, emissions of CO, HC, and toxic species. For many years, biodiesel fuel (and blends of biodiesel) has been promoted as a “clean fuel” alternative to conventional diesel. Based upon previous reviews by EPA, a common understanding has arisen that biodiesel usage reduces CO, HC, and PM emissions significantly, but increases NOx emissions slightly. This paper discusses a recent review of 94 published reports, from the period of 2000-2008. Assessments were made of the emissions impacts of biodistillate fuels from various engine types, operating conditions, control technologies, and fuel type. In each situation, emissions from the biodistillate case were compared with emissions from a reference diesel fuel case. Graphical displays were developed to show the effects of biodistillate blend level upon 4 emissions species (NOx, CO, HC, PM) from 3 engine types [heavy-duty (HD), light-duty (LD), and single cylinder test engine (TE)]. Results showed that use of biodistillates, even at a 20% blend level, substantially decreased emissions of CO, HC, and PM – generally by 10-20%. Although results varied considerably from one study to the next, similar benefits were seen in both LD and HD engines, regardless of engine technology or test condition. While data were much more limited for renewable diesel cases, these hydroprocessed fuels appeared to provide similar emissions reduction benefits for CO, HC, and PM. NOx emissions impacts were much smaller, and more difficult to discern. Though highly variable, most studies indicated a slight NOx increase when using B100 fuel. For HD engines, the authors’ best estimates are that NOx emissions increase 2-3% with B100, but are unchanged from conventional diesel fuel for B20 blends. Thus, this review indicates smaller NOx effects of biodistillates in HD engines than defined by EPA several years ago. In LD engines, NOx effects appear to be somewhat larger, with increases of 10-15% observed when using B20 and B100, respectively. More sophisticated statistical analyses are required to assess the significance of these small effects. INTRODUCTION AND BACKGROUND This effort is part of a larger study sponsored by the Coordinating Research Council (CRC), with the overall objective of assessing the state of knowledge regarding biofuels as blending materials for ultra-low sulfur diesel (ULSD) fuel in transportation applications. Besides emissions impacts, the entire study dealt with policy drivers, feedstocks, fuel production technologies, fuel properties and specifications, in-use handling and performance, and life-cycle impacts. Companion papers address these non-emissions topics. In this paper, the comprehensive term, biodistillate, is used to include all plantand animal-derived middle distillate fuels intended for use in diesel engines, regardless of the production technology used to manufacture the fuels. The two major biodistillate categories are:

Significant uncertainties in the prediction of pollutant transport and dispersion limit the accuracy of air quality in areas with complex terrain, such as along the California coastline, which suffers from elevated air pollutant concentrations. Typical Lagrangian air quality models treat the dispersion of plumes better than Eulerian models but the chemical interactions induced by the mixing of intersecting plumes are ignored. In contrast, Eulerian models treat the emissions as well mixed within each grid box. To address these limitations, an air quality model with in-line chemistry and meteorology that combines the advantages of the Eulerian and Lagrangian approach to air quality modeling has been developed. In order to evaluate the model, simulation results of ozone concentrations were compared against a commonly used photochemical model (CAMx) and with airborne data from a field study made in the San Diego area of southwestern California.

In an effort to develop engine/vehicle test methods that will reflect real-world emission characteristics, West Virginia University (WVU) designed and conducted a study on a Class-8 tractor with an electronically controlled diesel engine that was mounted on a chassis dynamometer in the Old Dominion University Langley full-scale wind tunnel. With wind speeds set at 88 km/hr in the tunnel, and the tractor operating at 88 km/hr on the chassis dynamometer, a Scanning Mobility Particle Sizer (SMPS) was employed for measuring PM size distributions and concentrations. The SMPS was housed in a container that was attached to a three-axis gantry in the wind tunnel. Background PM size-distributions were measured with another SMPS unit that was located upstream of the truck plume. Ambient temperatures were recorded at each of the sampling locations. The truck was also operated through transient tests with vehicle speeds varying from 65 to 88 km/hr, with a wind speed of 76 km/hr. Sampling of the plume with the truck operating at 88 km/hr revealed uni-modal distributions with geometric mean diameter (GMD) values ranging from 55 to 80 nm. When size distributions from five locations in the plume were corrected for concentration with respect to dilution, they were found to be similar. Size distributions and concentrations of PM emissions from the tractor operating at 88 km/hr were found to agree with those from few other heavy-duty diesel vehicles that this team of researchers had previously tested in the field using the WVU Transportable Heavy-duty Vehicle Emissions Testing Laboratory. Under idle operation a distinct nuclei mode was detected with GMD varying from 14 to 24 nm.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTField intercomparison of five types of fog water collectorsSusanne V. Hering, Donald L. Blumenthal, Robert L. Brewer, Alan. Gertler, Michael. Hoffmann, John A. Kadlecek, and Keith. PettusCite this: Environ. Sci. Technol. 1987, 21, 7, 654–663Publication Date (Print):July 1, 1987Publication History Published online1 May 2002Published inissue 1 July 1987https://pubs.acs.org/doi/10.1021/es00161a006https://doi.org/10.1021/es00161a006research-articleACS PublicationsRequest reuse permissionsArticle Views205Altmetric-Citations42LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts