air toxics Articles

  • Chromium toxicity

    Chromium, in the form of unidentified chromium compounds, occurs naturally in the earth’s crust and is widely distributed in air, water, soil, and food. Chromium (3+) is an essential trace element in humans. The general population is exposed to some chromium (6+) compounds, but the levels of exposure vary. Environmental exposure specifically to chromium(6+) compounds is difficult to quantify, ...


    By Valahia University

  • Ambient Air Quality Analysis of Toxic Gases and Priority

    The EPA regional offices who continuously monitor ambient air quality have determined that combustion by-products and automobile exhaust make up the largest source of air pollution throughout the U.S., with more severe conditions existing overseas. Despite concerns about the conditions outdoors, air quality in the workplace and home environment receive even more attention. The EPA’s list of ...


    By Buck Scientific Inc

  • Background Concentrations of 18 Air Toxics for North America

    ABSTRACT Of the 188 hazardous air pollutants, or 'air toxics,' identified by the U.S. Clean Air Act, 18 were targeted as the most important in a 10-city pilot study conducted in 2001 and 2002 as part of the National Air Toxics Trend Sites Program. This paper describes the pilot study. The U.S. Clean Air Act identifies 188 hazardous air pollutants (HAPs), or “air toxics,” associated with ...

  • The possible toxic effects of lead

    Lead is a chemical element in the periodic table that has the symbol Pb (Latin: plumbum) and atomic number 82. A soft, heavy, toxic and malleable lead is bluish white when freshly cut but tarnishes to dull gray when exposed to air, very dense metal which is very soft, highly malleable, ductile, and a relatively poor conductor of electricity. It is odourless. It is highly resistant to corrosion ...


    By Valahia University

  • Dispersion modelling of toxic air pollutants from fossil fuel combustion facilities

    The emissions of toxic air pollutants from three power plants and one oil refinery were measured for a period of six months and dispersion of pollutants were calculated by using Air Dispersion Modelling Software (ADMS–4). The plume concentration of carbon monoxide, oxides of nitrogen, sulphur dioxide and particulate matter were calculated over long distances to estimate the incremental ...


    By Inderscience Publishers

  • Canarina DISPER Software · air toxics dispersion model · algorithms 7

      Canarina DISPER Software · air toxics dispersion model   9.1.2 Downwind and Crosswind Distances  The model uses a Cartesian receptor network. All receptor points are converted to Cartesian (X,Y) coordinates ...

  • Citizens, engineers and air toxics: citizen participation in technology based standard setting

    This article analyses the potential for involving state and local citizen groups in technology-based standard setting for air toxics under the l990 US Clean Air Act. Congress hoped that by focusing on technology rather than risk that the standard setting process would be less contentious. This has not turned out to be the case. There are a number of points where scientists and engineers make ...


    By Inderscience Publishers

  • Toxic formaldehyde very common in homes

    EMSL Analytical provides formaldehyde testing solutions for industry and the public. Formaldehyde can be found in most homes across the country. The chemical is commonly used to manufacture numerous building materials and household items. The most significant source of formaldehyde in most homes is from pressed wood products made with formaldehyde containing adhesives. According to the EPA, “High ...


  • Accidental Releases Analysis for Toxic Aqueous Solutions

    As a result of the cluster rule for the control of the hazardous air pollutants, pulp and paper mills are in the process of further substituting chlorine with aqueous chlorine dioxide for their bleaching operations. In addition, ammonia aqueous solutions are applied by paper mills in various processes. An evaporation model including both heat and mass transfer for aqueous solutions has been ...

  • Accidental releases analysis for toxic aqueous solutions

    Abstract As a result of the cluster rule for the control of the hazardous air pollutants, pulp and paper mills are in the process of further substituting chlorine with aqueous chlorine dioxide for their bleaching operations. In addition, ammonia aqueous solutions are applied by paper mills in various processes. An evaporation model including both heat and mass transfer for aqueous ...


    By Trinity Consultants

  • Reactor modeling in heterogeneous photocatalysis: toxicity and biodegradability assessment

    Photocatalysis employing titanium dioxide is a useful method to degrade a wide variety of organic and inorganic pollutants from water and air. However, the application of this advanced oxidation process at industrial scale requires the development of mathematical models to design and scale-up photocatalytic reactors. In the present work, intrinsic kinetic expressions previously obtained in a ...


    By IWA Publishing

  • EPA mercury rules: Keeping the lights on while removing toxics from our air

    Next week the U.S. Environmental Protection Agency is expected to finalize new rules to reduce mercury and other toxic air emissions that will affect dozens of antiquated power plants currently operating without pollution controls. These rules have stirred debate in some circles as to whether retrofitting or retiring outdated plants will cause shortfalls in electricity capacity. How will new EPA ...

  • U.S. EPA Promulgates Final Air Toxics Standards for Compression Ignition Reciprocating Internal Combustion Engines (RICE)

    On March 3, 2010, U.S. EPA promulgated final National Emissions Standards for Hazardous Air Pollutants (NESHAP) for existing compression ignition (CI) stationary Reciprocating Internal Combustion Engines (RICE) that were not previously regulated by the existing, so called, RICE MACT (i.e., 40 CFR Part 63, Subpart ZZZZ).  The RICE MACT rule was originally promulgated in 2004.  The March ...


    By All4 Inc.

  • Biofilter Removal of VOCs and Toxics from Airborne Emissions

    Abstract Sewage treatment plants can emit significant quantities of volatile organic compounds (VOCs) and toxic air contaminants, but emission control by conventional methods has been difficult to achieve. The biofilter technology developed in a previous contract can satisfactorily control emissions from these plants and possibly from other sources of high-volume, low-concentration emissions ...


  • PETROTOX: An aquatic toxicity model for petroleum substances

    A spreadsheet model (PETROTOX) is described that predicts the aquatic toxicity of complex petroleum substances from petroleum substance composition. Substance composition is characterized by specifying mass fractions in constituent hydrocarbon blocks (HBs), based on available analytical information. The HBs are defined by their mass fractions within a defined carbon number range or boiling ...


    By John Wiley & Sons, Ltd.

  • Bioremoval of toxic metals from aqueous mixtures and recovery of biomass by dispersed-air flotation

    In the present paper the solid/liquid separation of suspended, metals-loaded biomass was mainly studied by successfully applying flotation. Industrial non-living biomass samples of different origins have been tried in the laboratory as sorbents of metal ions, with particular emphasis on Streptomyces rimosus, an effective for this purpose biomass. Dispersed-air flotation was used as the harvesting ...


    By Inderscience Publishers

  • A Method of Assessing Air Toxics Concentrations in Urban Areas Using Mobile Platform Measurements

    ABSTRACTThe objective of this paper is to demonstrate an approach to characterize the spatial variability in ambient air concentrations using mobile platform measurements. This approach may be useful for air toxics assessments in Environmental Justice applications, epidemiological studies, and environmental health risk assessments. In this study, we developed and applied a method to characterize ...

  • Intraurban variability of Ambient PM Arsenic and other air toxics metals case study

    The Missouri Department of Natural Resources (MoDNR) and Washington University participated in a project to collect and analyze air toxics metals data. It was funded through a Community Air Toxics Grant from the U.S. Environmental Protection Agency (USEPA). The study grew out of the southside St. Louis Community Air Project (CAP) which identified six hazardous air pollutants of concern including ...

  • Follow toxic gas standards for a smoother project

    Toxic gases, such as Hydrogen Sulfide and Sulfur Dioxide, can injure and kill quickly. Therefore, mitigation of these hazards must be fast and sure. The United States Occupational Safety and Health Administration (OSHA) and other authorities take detection of these gases very seriously. The American National Standards Institute/ American Petroleum Institute (ANSI/API) and ISA industry standards ...

  • Regionally Based Assessment of Persistent Toxic Substances

    Untitled Document EXECUTIVE SUMMARY In 1997 the United Nations Environment Programme (UNEP) Governing Council decided that immediate international action ...


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