Precipitation in Europe and eastern North America has become acidic, a result of increases in sulfuric and nitric acid aerosols produced by fossil-fuel combustion, metal smelting, and industrial processes. The increased use of tall smoke stacks and particle removers has increased long-range transport of acidic gases. Some metals and organic compounds also are transported atmospherically and deposited in acidic precipitation. In regions where acid-neutralizing capacity of soils and water is low, the pH of lakes and streams has decreased and concentrations of metals have increased. Aquatic organisms have been affected in all trophic levels (decomposers, primary producers, primary and secondary consumers); abundance, production, and growth have been reduced and sensitive species have been lost. Fish have suffered acute mortality, reduced growth, skeletal deformities, and especially reproductive failure. Valuable commercial and recreational fisheries have been lost in certain areas and such losses wi...

Acidic Precipitation and Its Consequences for Aquatic Ecosystems: A Review

A detailed study of the photochemistry of iodine and its oxides indicates that iodine species may play an important role in the tropospheric photochemical system. Methyl iodide, often observed in the marine troposphere with an average concentration of 5-10 ppt, is photolyzed and thereby produces I atoms. Chemical interactions with O3, HxOy, and NOx cause I to be converted to other inorganic compounds such as IO, HOI, IONO2, and I2. The production of these species and their subsequent recycling back to I can lead to the catalytic removal of tropospheric O3, the enhancement of the NO2/NO ratio, the destruction of HxOy free radicals, and the conversion of HO2 to OH. Ultimately, tropospheric inorganic iodine is removed by heterogeneous processes. Calculations using a numerical model to simulate tropospheric photochemistry indicate that iodine may have a strong impact upon the atmospheric O3-NOx-HxOy system. The magnitude of these effects is dependent upon the value of several uncertain rate constants and the primary source distributions of CH3I and other organic and inorganic iodine compounds.

Iodine: Its possible role in tropospheric photochemistry

With growing concern about climatic changes that could result from increased atmospheric carbon dioxide, it is appropriate to use the improved statistics on the production and use of fossil fuels which are now available and to review the CO 2 discharges to the atmosphere from fossil fuel burning. Data on global fuel production and the chemical composition of these fuels have been re-examined and an attempt has been made to estimate the fraction of fuel which is used in the petrochemicals industry or otherwise not soon oxidized. Available statistics now permit more systematic treatment of natural gas liquids than in earlier calculations. Values used for combustion efficiency and non-fuel use on a global scale still require some estimation and extrapolation from United States data but can be bounded with sufficient precision that they add little uncertainty to the calculation of global CO 2 emissions. Data now available permit the computation to be made with confidence that there are no major oversights. The differences from earlier calculations of CO 2 emissions are minor, well within the uncertainty limits in the data available. The fundamental problems of assembling a data set on global fuel production limit the utility of striving for too much precision at other steps in the calculation. Annual CO 2 emissions retain an uncertainty of 6-10%. Results of the calculations for 1980 through 1982 show decreases from 1979 CO 2 emissions. This is the first time since the end of World War I1 that the emissions have decreased 3 years in succession. During the period following the 1973 escalation of fuel prices, the growth rate of emissions has been less than half what it was during the 1950s and 1960s (1.5%/year since 1973 as opposed to 4.5%/year through the 1950s and 1960s). Most of the change is a result of decreased growth in the use of oil. DOI: 10.1111/j.1600-0889.1984.tb00245.x

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1600-0889.1984.tb00245.x

Carbon dioxide emissions from fossil fuels: a procedure for estimation and results for 1950-1982

Interest in coal residue research has recently been increased with anticipated increased dependence on coal as a source of energy. United States coal reserves are estimated at 3.6 trillion metric tons, from which 396 billion metric tons can economically be mined (Swanson et al. 1976). United States electric power utilities consume from 60 to 65% of the amount of coal produced (Brackett 1973). In 1974, the power industry utilized approximately 400 million tons of coal (Ash at Work 1975). The magnitude of trace element mobilization into the environment from fossil-fuels is substantial and is comparable to that originating from major sedimentary cycles such as river flows and natural sediments (Bertine and Goldberg 1971). Consequently, increasing regulatory measures have been imposed on power industries by federal and local authorities restricting the amount of coal residue entering the atmosphere.

Physical and chemical properties of fly ash from coal-fired power plants with reference to environmental impacts

Reactive chlorine in the lower atmosphere (as distinguished from chlorofluorocarbon-derived chlorine in the stratosphere) is important to considerations of precipitation acidity, corrosion, foliar damage, and chemistry of the marine boundary layer. Many of the chlorine-containing gases are difficult to measure, and natural sources appear to dominate anthropogenic sources for some chemical species. As a consequence, no satisfactory budget for reactive chlorine in the lower atmosphere is available. We have reviewed information on sources; source strengths; measurements in gas, aqueous, and aerosol phases; and chemical processes and from those data derive global budgets for nine reactive chlorine species and for reactive chlorine as a whole. The typical background abundance of reactive chlorine in the lower tropospheric is about 1.5 ppbv. The nine species, CH3 Cl, CH3 CCl3, HCl, CHClF2, Cl2* (thought to be HOCl and/or Cl2), CCl2 = CCl2, CH2 Cl2 , COCl2 , and CHCl3, each contribute at least a few percent to that total. The tropospheric reactive chlorine burden of approximately 8.3 Tg Cl is dominated by CH3 Cl (≈45 %) and CH3 CCl3 (≈25 %) and appears to be increasing by several percent per year. By far the most vigorous chlorine cycling appears to occur among seasalt aerosol, HCl, and Cl2*. The principal sources of reactive chlorine are volatilization from seasalt (enhanced by anthropogenically generated reactants), marine algae, volcanoes, and coal combustion (natural sources being thus quite important to the budget). It is anticipated that the concentrations of tropospheric reactive chlorine will continue to increase in the next several decades, particularly near urban areas in the rapidly developing countries.

Tropospheric budget of reactive chlorine

Inorganic composition of Belgian coals and coal ashes

Fly ash sampling carried out in a large combustion unit and in the chimney of a private house indicates that the composition of fly ash is significantly different from the original coal composition. Based on their mass-size distributions, the elements can be divided into three groups. A first group of elements is associated with large particles and is depleted relative to the original coal composition. A second group has a maximum concentration of small particles and is enriched in fly ash. For a third group, the mass-size functions show an intermediate behaviour. Thier concentration ratios in fly ash and coal are near unity. This division into enriched and depleted elements appears to be roughly independent of the operating conditions of the combustion process. There is some indication that the specific mass-size distribution in fly ash emitted by small domestic facilities is different from that in fly ash from larger facilities.

Chantal Block

Papers

Inorganic composition of Belgian coals and coal ashes

Study of fly ash emission during combustion of coal

Determination of trace elements in coal by instrumental neutron activation analysis

Determination of silicon and oxygen in coal and coal ash by 14-MeV neutron activation

Determination of lead in coal and coal ashes by flameless atomic absorption spectrometry