Complicated terrain and atmospheric stability are important factors in the predicting the dispersion of air pollutants. The aim of our study is to develop practical dispersion model for unstable conditions for regulatory use. The numerical model we adopted was a combination of the potential flow model and Lagrangian stochastic dispersion model. In this model, time-mean flow field is solved by the potential flow model and concentration field is calculated by Lagrangian stochastic model by using the flow field from potential model. Wind tunnel experiments simulating gas dispersion in the convective boundary layer were also done. The data sets of turbulent properties and concentrations obtained in the wind tunnel were used for the modification of dispersion model and model validation. Based on the developed model, user-friendly software applicable to dispersion over complicated terrain was also developed.
1 Introduction
This document presents a summary of ADMS model results compared against three well known field data sets: Prairie Grass. Kincaid and Indianapolis. Results are also presented for two U.S. models: ISCST and AERMOD.
ISC ST is the United States Environmental Protection Agency model. It is a so-called `old generation` model, similar to the UK R-91 model, based on the 1970`s description of boundary layer physics. Such models use several discrete categories to describe the stability of the atmospheric...
This year, the Air & Waste Management Association celebrates its centennial. The past 100 years have yielded remarkable technological advances, especially in the area of information technology (IT). Within our professional lifetimes, we have shifted from using manually typed memos and reports, pink telephone message slips and pagers to computer-generated reports, Internet data exchange, e-mail, and cell phones—now necessary tools for environment, health, and safety (EH&S) professionals. In a relatively short...
Untitled Document
Webster`s defines
recalcitrant as `to be stubbornly disobedient, obstinately defiant of authority
or restraint, difficult to manage or operate, not responsive to treatment.`
There are numerous
case studies of failed remedial systems, which in turn can be linked to the
remedial design team not fully understanding the site conditions. Often the
most effective way to clean up these recalcitrant sites is source/migration
control rather than intrusive remediation....
In 65 FR 21506 (dated April 21, 2000), the United States Environmental Protection Agency (U.S. EPA) proposed revisions to its air dispersion modeling guidance, found in 40 CFR 51, Appendix W (“Guideline on Air Quality Models”) that included replacing the Industrial Source Complex (ISC) model with the American Meteorological Society (AMS) / EPA Regulatory Model (AERMOD) as the regulatory default model for state and federal permitting applications. It is expected that when this switch is finally promulgated, there...
Over the last two decades a variety of portable or transportable gas chromatographs (GC) have been specifically designed for field use. Each instrument has introduced innovations that have simplified the task of on site air monitoring. Portable instrument users are well aware of the advantages of field sampling. These advantages include more representative results because there is no sample degradation during transport and rapid answers because results are available almost immediately. Results at the field site...
AbstractIn this paper, we present results from field studies of the application of a new laser based spectrometer incorporated with real-time dispersion modeling techniques to measure fugitive emissions from gas processing facilities. While open-path FTIR spectrometers can measure a variety of gaseous species, they suffer from the drawbacks of being large, expensive and of limited range. Also, uncertainty in results caused by spectral overlap has been a matter of concern to regulatory organizations. The laser...
In the application of dispersion modelling for regulatory purposes questions frequently arise regarding the meteorological data used for the study: in particular how many years data are sufficient; is the meteorological site representative of the dispersion site? Although studies have been conducted on the impact of meteorology from different years on ground level concentrations from point sources [1,2] these studies have generally focussed on the source contribution, without consideration of background concentrati...
At the moment there are no field proven technologies available to remove dissolved hydrocarbons (aliphatics and mainly aromatics) from produced water on offshore platforms. Following a joined study of the NOGEPA (The Netherlands Oil and Gas Exploration and Production Association) and the Dutch Government, the Macro Porous Polymer Extraction (MPPE) technology was selected from 55 technologies as one of the most promising one. The MPPE process is removing the aromatics and aliphatics by an extraction process with...
Life cycle impact assessment is usually plagued by the assumptions of site independence and uniform mixing of pollutants in a compartment (e.g., atmosphere), which are not valid for all air pollutants. In this paper we propose using the concept of exposure efficiency to simplify the damage pathway analysis without compromising the consideration of site-dependent characteristics. Our case study of increasing insulation in new homes in the US from the MEC1993 to IECC2000 level yields 6,442 TJ (6,111 GBTU) of energy...
Abstract
Albania is a rich country in oil, mineral and water sources as well as a very polluted one in Europe There are a lot of wastes that couldn’t be managed in existing circumstances. At the present many oil and gas fields are in the third or depleted phase of the exploitation, while a lot of mines are abandoned. In this frame the paper presents some considerations to use them as underground storage for waste management.
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The Rockland County (New York) Cocomposting Facility began operations in February, 1999, processing biosolids from the five publicly owned treatment works (POTWs) in the county. The Rockland County Solid Waste Management Authority (RCSWMA) owns the facility, but contracted with Waste Management of New York to design, build and operate (DBO) the 110 wet tons/day agitated bin composting facility located in Hilburn. From the earliest stages of development,
RCSWMA has focused on odor control provisions for the...
The operation of the anaerobic lagoon adjacent to Isfahan Wastewater Treatment Plant was studied over a 12- month period. The rate of organic loading, BOD and SS removal efficiencies and their relationships with organic reductions and ambient temperature were studied. A high correlation was found to hold among temperature, organic loading rate, and BOD 5 removal. A correlation coefficient of 87% was obtained for temperature and BOD 5 removal efficiency and that for temperature and organic loading was 83%. The...
Abstract
The development of numerical codes, as well as pre- and post-processors to support these codes, has made the discipline of groundwater modelling increasingly more automated and efficient. The value of such modelling is reliant on the site-specific data used to build and calibrate the models. The integration of EarthSoft`s EQuISÒ Geology and any of several popular modelling environments results in a data management and analysis system that is more complete than the modelling system alone. Water level...
Most practical dispersion models used for regulatory purposes assume that the meteorological conditions are constant over the averaging period and calculate ensemble average concentrations. In practice, although the meteorological conditions may be constant, during the averaging period there will be short time scale variations due to boundary layer turbulence. The turbulent fluctuations will lead to variations in short term concentration.
Acknowledging the underestimate of short term peak concentrations if these...
When determining the consequences of accidental release flow rates from pressurized gas systems, it is important to select the appropriate type of air pollution dispersion model. For released gases which are lighter than or equal to the ambient air density, Gaussian dispersion models as described in Beychok`s text1 should be used. For released gases which are heavier than air, a dense gas model such as SLAB2 or DEGADIS3 should be used.
It is also important to determine realistic flow rates for accidental release...
Air dispersion modeling has been evolving since before the 1930s. Over the last 15-25 years, strict environmental regulations and the availability of personal computers have fueled an immense growth in the use of mathematical models to predict the dispersion of air pollution plumes. Beychok`s recently published book, `Fundamentals Of Stack Gas Dispersion`, details the evolution of the widely used Gaussian air dispersion models and their inherent assumptions and constraints.
Unfortunately, many users of such...
Introduction
Climate researcher Klaus Hasselmann, Director of the Max-Planck-Institut (MPI) for Meteorology in Hamburg and a project co-ordinator of EC’s Environment and Climate Programme, was one of the first scientists to warn that recently observed global warming trends have a discernible human related forcing component. Climate model calculations show, that global warming is closely related to rising atmospheric concentrations of greenhouse gases (GHGs) as consequence of man’s activity. Since pre-industrial...
Modeling may be necessary to estimate the changes in ambient air quality, both locally and at a distance, caused by a particular set of emissions. Modeling can be appropriate for new plants and for modifications to existing plants. This note provides guidance on some models that may be useful in the context of typical World Bank Group projects.
Introduction
Air quality is an issue of increasing concern in many countries, and projects which either introduce new sources of emissions or are designed to reduce...
Abstract This paper presents data on the source of PCDDs/PCDFs in cement plant stack emissions, demonstrating that these emissions are not necessarily all created by the process. The data potentially demonstrates that some of the PCDDs/PCDFs in the emissions are pre-existing dioxins and furans that are vaporized out of the kiln raw feed. This calls into question the assumption that PCDD/PCDF emissions can be decreased below a certain point. The EPA has acknowledged resuspended PCDD/PCDF emissions, such as from...
Introduction
The energy level of some types of radiation is high enough so that when they interact with matter they cause the formation of electrically charged particles or ion-pairs and break molecular bonds. These so-called ionising radiations are by their nature potentially harmful to life; at high doses they can be lethal and at lower doses can cause genetic damage. Ionising radiation occurs naturally, and life on Earth has always been exposed to it. Human activities can, however, enhance exposure, and new...
STEP ONE: ASSESSMENT AND SURVEYThe first step of the Asbestos Management Program is to do an asbestos survey to assess the location, identify the type of asbestos, the condition of the asbestos and identify a maintenance record. This asbestos inventory or assessment is usually carried out by an independent consulting firm. This assessment or survey will include:
Identification and location of the Asbestos Containing Materials (ACM) Assessing the condition of asbestos and its accessibility. Preparing a long term...
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