International Journal of Environment and Pollution (26 papers in press)
Verification of the EDMS model adapted to Budapest Liszt Ferenc Airport
by Veronika O. Groma, Zita Ferenczi, János Osán, Szabina Török, Roland Steib
Abstract: This paper quantifies the ability of the Emission and Dispersion Modelling System (EDMS) to reproduce observed pollutant concentrations in the vicinity of a European airport. For the validation, one receptor point was selected at Liszt Ferenc International Airport, Terminal Building 2, where an air quality monitoring station operates. Modelling results superimposed on background concentrations generated from a suburban monitoring station in the vicinity were compared with hourly measured concentrations using statistical indicators for three compounds (CO, NOX and PM10). Acceptable correlation coefficients (0.53-0.76) were obtained, although in case of PM10 the modelled values show slight but significant underestimation for the entire studied period. Also, an obvious overestimate of NOX concentration was found for certain days. Pollution roses were generated that highlighted the spatial distribution of the pollution sources that affect the air quality at the receptor point. Sensitivity of the model to input data, especially to the emission inventory, is discussed. The contribution of aircraft ground movement and apron area emission was found to be well characterised, but in the case of CO and NOX a small (15
Keywords: airport air quality; dispersion modelling; EDMS modeling system.
Characterisation and assessment of spatiotemporal variations in nutrient concentrations and fluxes in an urban watershed: Passaic River Basin, New Jersey, USA
by Jinglong Du, Huang Feng
Abstract: This study investigated the spatial and temporal variations in total inorganic nitrogen (TIN) and total phosphorus (TP), and examined the relationship between water quality and urbanisation in the Passaic River watershed. The results indicate three things. (1) The mean TIN and TP concentrations and fluxes showed a relatively steadily decreasing trend in last two decades. (2) TIN and TP concentrations in summer and autumn were higher than those in spring and winter, but the fluxes were lower than those in spring and winter. At the same time, TIN and TP concentrations in normal flow condition were also higher than those in storm flow condition, but the fluxes were lower than those in storm flow condition. (3) Spatially, water quality in upper reaches of the rivers was better than that of middle and lower reaches, and the nutrient concentrations in Water Management Area (WMA) 4 were the highest, followed by WMA 6 and WMA 3. Land use change, population growth, urbanisation and environmental protection investment were the main factors that influence the change of environment in the Passaic River Basin.
Keywords: total inorganic nitrogen; total phosphorus; spatial and temporal variations; geographic information system; Passaic River.
Influences of single and binary metal mixtures on microbial growth in sandy soil of infiltration site
by In Chul Kong, Kyung Seok Ko
Abstract: Effects of single and binary mixtures of metals on microbial biofilm growth were evaluated on silty-sandy soil collected from an artificial storage and recovery (ASR) site. The effects of metals on the adenosine triphosphate (ATP) content and viable cell count (VCC) showed considerable differences depending on the metal types and concentrations, whereas dehydrogenase activity (DHA) did not change significantly. The sensitivity of the ATP and VCC measurements was also greater than that of DHA. Toxicity based on the ATP content was Cu ≈ Cd > Cr ≈ As(III) ≈ As(V). In the presencence of the binary metal mixtures, a synergistic and additive effect was commonly observed for the ATP contents and VCC, respectively. Therefore, understanding the effects of metal mixtures is essential for proper assessment of the contaminated environment. This study also indicated that the evaluation of metal effects may be considerably influenced by the endpoints of microbial growth measurement.
Keywords: ATP; DHA; metal mixture; microbial growth; VCC.
Adsorption of cobalt() by HCl and H2O2 modified activated carbon
by Zhen Liu, Yanguo Zhang, Bing Han, Zhongchao Tan, Qinghai Li
Abstract: Activated carbon prepared from coconut husk was modified with HCl and H2O2 and tested for the removal of cobalt(Ⅲ) in aqueous solutions. The modification altered the activated carbon pore structures and quantities of the functional group. Batch-mode adsorption experiments were carried out for activated carbons modified at different temperatures (25-75℃), reagent concentrations (0.01-0.04 molL-1), and times (1-8 h). Results show that, under optimum experimental conditions, H2O2 modified activated carbon performs better in terms of adsorption efficiency. Cobalt(Ⅲ) adsorption efficiency is approximately 86%, and HCl modified activated carbon is around 79%.
Keywords: activated carbon; adsorption; modified activated carbon; cobalt(III).
Spatial water quality estimation of artificial lakes in Central Poland
by Barbara Krawczyk, Dominik Szczukocki, Monika Szczepanska, Karolina Czarny, Piotr Seliger, Sławomira Skrzypek
Abstract: Cyanobacterial blooms that occur in the two largest water reservoirs located in Central Poland (Jeziorsko and Sulej
Keywords: environmental monitoring; water quality parameters; water reservoirs; cyanobacterial blooms; cluster analysis; principal component analysis.
Are toxic load-based toxicity models consistent with experimental observations? Independent analysis of steady-exposure data from the 20122013 ECBC/NAMRU-D toxicological experiments
by Alexander Slawik, Kevin Axelrod, James Silva, Ivo Dimitrov, Jeffry Urban, Nathan Platt
Abstract: This work explores the validity of the toxic load model, which is often used to predict the health effects of airborne releases of toxic materials. In 2012 and 2013 the US Army's Edgewood Chemical and Biological Center (ECBC) and the Naval Medical Research Unit Dayton (NAMRU-D) conducted toxicological experiments to explore the effects of time-varying inhalation exposures of hydrogen cyanide gas on rats. Our independent analysis of the experimental data indicates that the toxic load model is not valid over the full range of the experiments exposure durations, assuming that there was no systematic experimental error. The model fits the data poorly for exposure durations under 10 minutes.
Keywords: toxicology; toxic load; toxic load model; toxicity model; hazardous materials; acute inhalation exposure; steady exposures; consequence assessment; health effects; health and exposure assessment; hydrogen cyanide; rats; ECBC; NAMRU-D; DTRA.
Special Issue on: Organic Pollutants in Different Compartments of the Biosphere - Origins, Emissions, Abatement and Destruction, Risk Analysis
Catalytic decomposition of 1,2-dichlorobenzene over V2O5/TiO2 catalysts blending with typical carbon nanotubes
by Cuicui Du, Xuan Cao, Shengyong Lu
Abstract: A series of V2O5/TiO2-CNTs catalysts, prepared by the sol-gel method, were studied on their activities for 1,2-dichlorobenzene (1,2-DCBz) decomposition. Three kinds of typical carbon nanotubes, single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNT1) with outer diameter of 20-30 nm, and multi-walled carbon nanotubes with thinner walls (MWCNT2), were used. The gelling time has an important effect on the textural properties and acidity of the catalysts prepared by this sol-gel method. Owing to its excellent adsorption ability, the V2O5/TiO2-SWCNTs exhibit the best reactivity at low temperature (150
Keywords: catalytic oxidation; carbon nanotubes; 1,2-dichlorobenzene; gelling time.
Fly ash from a Belgian stoker-type municipal solid waste incinerator
by Mengmei Zhang, Junhong Liao, Alfons Buekens, Xiaodong Li
Abstract: This study establishes some salient characteristics of fly ash from municipal solid waste incineration by combining various instrumental analytical techniques (SEM-EDS, XRD and XRF, etc.) while analysing size-classified fractions of high-temperature (HT) and baghouse (BH) dust. First, the two samples were sieved in eight (HT) or six (BH) size fractions and these were separately analysed for PCDD/F, PCB and PAH. These two samples, showing distinct differences from each other, were collected from a small MSWI stoker plant in Belgium with frequent operational problems. The BH sample presented more homogeneity than the HT sample. The variation in main elemental composition between different fractions of the same sample was limited; while a growing concentration of heavy metals was observed with falling size of particle. The loads of PCDD/F and PCB in the BH sample are one to two orders of magnitude larger than those in HT samples, while the load of PAH shows no obvious evolution. High internal correlation was found for the contents of PCB and PCDD/F and even higher for dl-PCB and PCDD/F. The primary purpose of this study is verifying in how far such off-line fly ash analyses supplement the continuous routine emission monitoring, mandatory for such plants, and developing an additional understanding of the operating state of the plant and its potential to form PCDD/F, PCB and PAH. The secondary purpose is to test a range of methods for studying fly ash arising from large-scale plant in China, provide a West European point of reference and improve operating methods and decrease emissions.
Keywords: fly ash; municipal solid waste incineration; polychlorinated dibenzo-p-dioxins; polychlorinated dibenzofurans; polychlorinated biphenyls; polycyclic aromatic hydrocarbons.
Polychlorinated dibenzo-p-dioxins and dibenzofurans in off-gas and residue during desulphurisation of iron ore sintering off-gas
by Yibo Zhang, Rong Zhu, Jingling Yang, Alfons Buekens, Hui Wang, Yun Wang, Pu Zhang
Abstract: The iron ore sintering process has always been considered as a key issue in the discharge of PCDD/Fs pollutants. In this study, the concentration of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), in brief dioxins (PCDD/Fs), was measured in the off-gas and solid by-products from two selected and distinct desulphurisation processes, one operating wet and one dry on sintering off-gas. All samples analysed showed a PCDFs to PCDDs ratio larger than unity. The removal efficiency obtained in the two facilities was almost identical, about 40%, when based on the toxic equivalent quantity (TEQ); the removal efficiency of PCDD/Fs was higher, however, with 40.4% and 63.5%, respectively, for the wet and the dry processes. Unexpectedly, the removal efficiency was strongly dependent on chlorination level and far higher for low chlorinated PCDD/Fs than for high chlorinated PCDD/Fs, showing even negative removal efficiency. Moreover, the Hagenmaier profile was markedly different for the gas phase samples than for residue. These findings suggest that these results are not representative for steady-state conditions. During desulphurisation both physical effects, such as adsorption, and chemical reactions, as well as memory effects, may have occurred. This study provides some supporting information for multiple pollutant control and disposal of desulphurisation by-products, taking into account its PCDD/Fs load. Further work is needed to explain, e.g., the deep difference between the two PCDD/Fs sintering signatures at the entrance and at the exit of the two lines, the removal mechanisms operating during wet and dry desulphurisation and the possibilities to improve the PCDD/Fs removal during gas treatment. Further work should emphasise establishing balances over both units, identifying the rate-controlling steps in wet and dry SO2 removal systems and deriving complete fingerprints, so that their mechanisms of influence may be established.
Keywords: PCDD/Fs; desulphurisation; iron ore sintering; off-gas cleaning; by-product.
Soil pollution by chlorobenzenes and polychlorinated biphenyls from an electronic waste recycling area in northern Vietnam
by Chiya Nishimura, Go Suzuki, Hidenori Matsukami, Tetsuro Agusa, Masaki Takaoka, Shin Takahashi, Nguyen Minh Tue, Pham Hung Viet, Shinsuke Tanabe, Hidetaka Takigami, Takashi Fujimori
Abstract: We investigated soil pollution by chlorobenzenes (CBzs) and polychlorinated biphenyls (PCBs) in Bui Dau, a village in Vietnam known for informal electronic waste (e-waste) recycling activities. The total concentrations of CBzs and PCBs ranged from 17 to 1400 ng/g and 2.0 to 7200 ng/g, respectively, with the highest concentrations of the two compounds detected at e-waste open burning sites (EOBSs) in the survey area. The homologue profiles of CBzs and PCBs in the soils collected at the EOBSs were different from those in municipal solid waste incinerator (MSWI) fly ash. This result suggests that CBzs are formed from different processes during the open burning of e-waste and municipal solid waste incineration, even though both are combustion processes. The spatial distributions of CBzs and PCBs, and the results of a multiple comparison test, showed that these compounds were released from the EOBSs and spread around this survey area.
Keywords: chlorobenzenes; polychlorinated biphenyls; e-waste open burning; soil; Vietnam.
Effect of microwave treatment onto activated carbon produced from pecan nut shells for tartrazine removal from aqueous media
by Jonatan Torres-Pérez, Gabriela Muñoz-Armenta, Simón Yobanny Reyes-López
Abstract: The processes used to fabricate carbonaceous materials with sorption capacity are expensive and require the exploitation of natural resources. The use of microwave treatment for activated carbons is an innovative and cheaper method than traditional chemical activation. To develop a sustainable carbonaceous material with sorption properties, the present study used four methods to prepare activated carbon using pecan nut shells, an agricultural waste, as an alternative precursor instead of conventional materials such as coconut shells or wood. The preparation methods were: carbonisation (NAC), carbonisation/water activation (NAC-H2O), carbonisation/microwave treatment (NAC-MW) and carbonisation/activation/microwave treatment (NAC-H2O-MW). The prepared material was characterised by pHPZC and total ash content determination, BET surface area analysis, Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) analysis. The sorption equilibrium time for the tartrazine dye sorption was determined. The prepared activated carbons that presented the best sorption capacity were NAC-H2O (8.2 mg/g) and NAC-MW (5.1 mg/g); the sorption equilibrium time was 24 h for both materials. The sorption experiments showed a good fitting to a pseudo second order equation and to the Freundlich model.
Keywords: activated carbon; microwave activation; tartrazine; pecan nut shells; adsorption.
Special Issue on: Challenges in the Development of Large-scale Pollution Models
Urban areas parameterisation for CFD simulation and cities air quality analysis.
by Maria Grazia Badas, Luca Salvadori, Michela Garau, Giorgio Querzoli, Simone Ferrari
Abstract: The aim of this work is to highlight the importance of a site-specific characterisation of urban areas needed for Computational Fluid Dynamics (CFD) simulations and urban air quality studies. As a case study, we consider Cagliari, an Italian town, whose heterogeneous urban form can be representative of many European historical towns, quite different from large American cities that are generally analysed in the literature. Basic steps needed to compute the main morphometric and fluid dynamics parameters from Digital Elevation Models (DEM) are reviewed and some possible caveats on using gridded DEM analysis are highlighted. Results show how site-specific analysis provides quite different parametrisations from those obtained by literature results, which cannot be transposed to other urban contexts. Morphometric site-specific analysis represents a key issue in urban numerical simulations, since the application of non-representative morphometric input data may dramatically affect their results.
Keywords: morphometric parameters; urban aerodynamic roughness; urban canopy model.
On convergence of difference schemes for Dirichlet IBVP for two-dimensional quasilinear parabolic equations
by Piotr Matus, Dmitriy Poliakov, Dorota Pylak
Abstract: For the Dirichlet initial boundary value problem (IBVP) for two-dimensional quasilinear parabolic equations, a monotone linearised difference scheme is constructed. The uniform parabolicity condition is assumed to be fulfilled for the sign-alternating solution only in the domain of exact solution values (unbounded nonlinearity). On the basis of the proved new corollaries of the maximum principle not only two-sided estimates for the approximate solution y but also its belonging to the domain of exact solution values are established. We assume that the solution is continuous and its first derivatives have discontinuities of the first kind in the neighborhood of the finite number of discontinuity lines. An existence of a time derivative in any sense is not assumed. Convergence of the approximate solution to a generalized solution of differential problem in the grid norm L2 is proved.
Keywords: difference schemes ; generalised solution ; initial boundary valuernproblem ; 2D quasilinear parabolic equation ; unbounded nonlinearity ; two-sided estimates.
The treatment method of general heat treatment of waste water from metal manufacturing based on photocatalysis
by Ning Qiu
Abstract: Photocatalytic treatment of emulsified waste liquid after pretreatment is carried out using TiO2 as catalyst, and the influence of crystal structure, particle size, amounts of catalyst and the initial pH value on the removal ratio of the chemical oxygen demand (COD) are studied. The results show that in the conditions that 0.5% quality point, P25-1 photocatalyst, 6.5 pH value and 90 min processing, the treatment effect is most ideal.
Keywords: heat treatment cleaning; emulsion; photocatalysis; post-treatment.
Special Issue on: HARMO 18 Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes
Evaluation of parametric laws for computing the wind speed profile in the urban boundary layer: Comparison to two dimensional building water channel data
by Annalisa Di Bernardino, Armando Pelliccioni, Paolo Monti, Giovanni Leuzzi, Giorgio Querzoli
Abstract: The wind flow in urban canopies depends mostly on the geometry of the roughness elements present above the surface. Given the impracticality of obtaining relationships strictly related to the governing equations, the wind-speed profile is evaluated in current practice by means of similarity laws, whose parameters are usually based on the morphometric method. This study analyses some of the empirical laws found in the literature adopted to determine the wind-speed profile above the canopy layer in neutral conditions. Their performance is tested against water-channel data simulating an idealised two-dimensional array of regular buildings of constant height.
Keywords: building; canopy layer; logarithmic law; neutral boundary layer; similarity theory; wind profile.
Validation of numerically forecasted vertical temperature profile with measurements for dispersion modelling
by Bostjan Grasic, Primoz Mlakar, Marija Zlata Boznar, Jus Kocijan
Abstract: Modelling of air pollution dispersion in the immediate vicinity of industrial sources over a complex terrain requires proper meteorological input data regarding the state of the atmosphere. For this purpose, numerical weather prediction-model results, rather than direct measurements, are becoming more widely used. In order to ensure high-quality modelling of the air-pollution dispersion, the forecast meteorological input data have to be of high quality. The quality of numerically obtained data has to therefore be validated with measurements. Measurements of the vertical temperature profile, which is vital, with Radio Acoustic Sounding System (RASS) were used in this study. The paper presents the validation of the forecast vertical temperature profile over the complex terrain of the Krko Basin. The validation is carried out with sensor measurements from a 70 metre tall tower and remote RASS measurements. 13 months worth of data is used for the validation study.
Keywords: vertical temperature profile; weather forecast validation; WRF; RASS; complex terrain.
Computer simulations of the impact of air pollution on the quality of life and health risks in Bulgaria
by Ivelina Georgieva, Vladimir Ivanov
Abstract: The air is the living environment of human beings and atmospheric composition has a great importance for the quality of life and human health. Air Quality (AQ) is a key element for the well-being and quality of life of European citizens. The objective of the present work is performing reliable, comprehensive and detailed studies of the impact of lower atmosphere composition on quality of life for the population in Bulgaria. The AQ study is based on atmospheric composition numerical simulations. USEPA Models3 System was applied as tool for 3D simulations. The AQ Index provides an integrated assessment of the impact of air pollutants on human health and is calculated on the basis of the air pollutant concentration obtained from numerical modelling. A comprehensive ensemble of atmospheric composition fields was created and diurnal variations of the recurrence spatial distribution of different classes of the AQI are demonstrated in the present work.
Keywords: air quality; ensemble of numerical simulation; air quality indices; quality of life; health risks.
Contribution of different emission sources to the atmospheric composition format in the city of Sofia
by Georgi Gadzhev, Ivelina Georgieva, Kostadin Ganev, Nikolay Miloshev
Abstract: Some extensive numerical simulations of the atmospheric composition fields in Sofia city have been recently performed and an ensemble, comprehensive enough as to provide statistically reliable assessment of the atmospheric composition climate has been constructed. The US EPA Models-3 system was chosen as a modelling tool. As the NCEP Global Analysis Data with 1 degree resolution is used as meteorological background, the system nesting capabilities were applied for downscaling the simulations to a 1 km resolution. The national emission inventory and the TNO inventory were used as an emission input. The study is based on a large number of numerical simulations carried out day by day for years 2008-2014 for six emission scenarios with all the emissions included and with reduced: all the emissions, emissions from energetics, from non-industrial, industrial combustions and road transport. Results concerning the contribution of the different emission categories are demonstrated in the paper.
Keywords: urban air pollution; computer simulations; SNAP categories; contribution of different emission sources.
Effect of surface roughness on turbulence, ventilation and pollutant dispersion over a hypothetical urban area
by Ziwei Mo
Abstract: Wind flows and pollutant dispersion over cities are strongly affected by urban morphology. Scientific evidence measuring the effect of surface roughness on transport processes is needed to effectuate air quality strategy. Based on idealised building models assembled by ribs and LEGO
Keywords: air exchange rate; pollutant dispersion coefficient; rough-surface drag; street-level ventilation; wind tunnel experiments.
A hybrid CFD RANS/Lagrangian approach to model atmospheric dispersion of pollutants in complex urban geometries
by Meïssam L. Bahlali, Eric Dupont, Bertrand Carissimo
Abstract: In the general context of atmospheric dispersion in urban neighborhood or around an industrial site, Lagrangian models consist of calculating and tracking the trajectories of particles of pollutant emitted into the turbulent atmosphere. These models are particularly suitable for the study of complex, unsteady or inhomogeneous flows, which is precisely the case of atmospheric flows in urban areas and complex industrial sites. They are also recommended to deal with dispersion near the sources. Usually, these models use wind and turbulence fields computed by an external code.
In this work, the objective is to compare the Lagrangian and the Eulerian atmospheric dispersion modules in the same Computational Fluid Dynamics (CFD) open source code (Code_Saturne), therefore using the same wind and turbulence field for both. For each simulation, we compare the turbulent dispersion of pollutants obtained with the Lagrangian approach to the existing results previously obtained with the Eulerian methods. The Lagrangian stochastic model used in this work is the Simplified Langevin Model (SLM) of Pope (2000) and pertains to the approaches referred to as PDF (Probability Density Function) methods. This formulation of model has been extensively used in the fields of turbulent combustion or multiphase flows, but to our knowledge, it has not been widely used in atmospheric applications. In this paper, we first show that the SLM respects the well-mixed criterion for uniform and non-uniform flows. Then, we validate the model in the case of a continuous point release with uniform mean wind speed and turbulent diffusivity, by checking with the existing analytical solution. Finally, we validate the model with several experimental campaigns, considering atmospheric stratification and buildings. The first field experiment program considered in this paper has been conducted on the SIRTA site (Site Instrumental de Recherche par T
Keywords: atmospheric dispersion; Lagrangian stochastic modelling; turbulence; CFD.
Data assimilation at local scale to improve CFD simulations of atmospheric dispersion: application to 1D shallow-water equations and method comparisons
by Cécile L. Defforge, Bertrand Carissimo, Marc Bocquet, Patrick Armand, Raphaël Bresson
Abstract: Atmospheric dispersion modelling requires meteorological inputs over local domains with possibly complex topographies. These local wind fields may be difficult to simulate with CFD models, in particular because of their sensitivity to geometrical features and to model inputs, especially the boundary conditions which are generally provided by larger-scale models or measurements. Using data assimilation, a few measurements inside the domain could add information to the imprecise boundary conditions and thus greatly enhance the precision of the dispersion simulations. Three data assimilation techniques (3DVar, the back and forth nudging algorithm, and the iterative ensemble Kalman smoother) have been adapted to local scale simulations by taking boundary conditions into account instead of initial conditions for which they are usually applied. Their performances have been evaluated at small scales, with a simple flow, using 1D solution of the shallow water equations.
Keywords: data assimilation; local scale simulation; boundary conditions; shallow water model; 3D-Var; back and forth nudging algorithm; iterative ensemble Kalman smoother.
QualeAria: European and national scale air quality forecast system performance evaluation
by Alessio D'Allura, Matteo Paolo Costa, Camillo Silibello
Abstract: Air quality forecasts are operationally provided by some of the Italian Regional Environmental Agencies. Some of them adopted a coherent modelling framework and implemented the same boundary conditions provided by the national forecast system QualeAria. This network of regional/urban scale air quality forecast systems represents an effective example of consistent methodology adopted to address the requirements of the European Directives, to assess, manage and forecast the state of the atmosphere. QualeAria has been evaluated against the observations recorded by regional air quality networks for the years 2015/2016. The role of phenomena generated at regional/global scales, along with the key role of fine-grained information available at local scale has been investigated by comparing QualeAria with the linked systems at different scales.
Keywords: air quality forecast; model evaluation; bias correction; score analysis.
Large-eddy simulation studies for predicting plume concentrations around nuclear facilities using an overlapping technique
by Hiromasa Nakayama, Tetsuya Takemi
Abstract: We propose, in emergency response to nuclear accidents, a practical and quick local-scale atmospheric dispersion calculation method using an overlapping technique. First, we pre-calculate large-eddy simulation (LESs) of plume dispersion around an actual nuclear facility under idealised atmospheric conditions with 36 wind-direction cases and make a dataset of the 10-minute averaged concentrations for each wind direction case. Then, we conduct LESs of plume dispersion for 1-hour periods under realistic atmospheric conditions using the meteorological data and estimate the spatial distributions of the 1-hour averaged concentrations by overlapping the pre-calculated concentration data depending on the frequency of the mean wind directions. It is shown that the concentration distribution patterns are well reproduced in comparison with those under the realistic conditions. It is concluded that the atmospheric dispersion calculation method using the overlapping technique has potentially a high performance in emergency responses to nuclear accidents.
Keywords: large-eddy simulation; plume dispersion; overlapping technique; emergency response.
Downwind chlorine hazard estimates for the 20152016 Jack Rabbit II campaign
by Nathan Platt, Kevin Luong, Jeffry Urban
Abstract: We present estimates of the downwind inhalation health hazard to humans based on measurements during the Jack Rabbit II campaign, a two-year experimental campaign of large-scale outdoor chlorine releases at the US Armys Dugway Proving Ground. We estimated the chlorine inhalation hazard at each downwind arc of chlorine sensors using two methods. We calculated the probability of lethal, severe, and mild health effects in civilian and military populations using a modification of the toxic load model, a US Department of Defense (DoD)-approved toxicological model. We also determined whether the chlorine exposures exceeded the US Environmental Protection Agencys Acute Exposure Guideline Levels (AEGLs) for chlorine at all three levels of health effects severity. The chlorine releases considered in this study were in the range of 7 to 9 metric tons. Lethal, severe, and mild health effects are expected up to 1 km, 2 to 5 km, and more than 11 km downwind from the release, respectively. The AEGL-3, AEGL-2, and AEGL-1 acute inhalation hazard thresholds are expected to be exceeded at 2 to 5 km, up to 11 km, and beyond 11 km downwind from the release, respectively. We note that since our hazard distance estimates are based on chlorine concentrations that were directly measured (i.e., not modelled), the accuracy of these estimates depends only on the quality of the health effects models we applied, and not on the quality of any atmospheric transport and dispersion model or container release (chemical source term) model
Keywords: chlorine exposure health effects; toxic industrial chemicals; Jack Rabbit II; toxic load model; AEGLs.
Validation of dispersion models using Cabauw field experiments and numerical weather re-analysis
by Gertie Geertsema, Marko Kaasik
Abstract: The Gaussian atmospheric dispersion model AEROPOL is validated against the classical Cabauw dispersion experiment, driven by (1) on-site meteorological data and (2) meteorological data from the numerical weather model HARMONIE. The meteorological forecast time used at the time of the release is 10 to 14 hours ahead of the analysis time. The results from the combination of AEROPOL with on-site data are slightly better than with re-analysed meteorology. The near-surface concentrations based on the combination of AEROPOL with the model forecasts are in general lower than the concentrations from the combination of AEROPOL with on-site data and are also lower than the observed concentrations. The combination of AEROPOL with meteorological model results in a mismatch between the modelled position of the plume axis with the observed plume axis. The results show a significant improvement in the HARMONIE version 38 with respect to the HARMONIE version 37.
Keywords: Cabauw dispersion experiment; HARMONIE; AEROPOL; HARMO initiative; model validation.
Special Issue on: Dioxins, Sources and Effects, Formation and Abatement
GC-HRMS analysis for POPs and new POPs with GC-Tof/MS techniques
by Takumi Takasuga