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Studies of Soils, Soil Water and Stream Water at a Small Catchment near Guiyang, China
1998
Larssen, Thorjørn | Jiling, Xiong | Vogt, Rolf D. | Seip, Hans Martin | Bohan, Liao | Dianwu, Zhao
Acid deposition is considered to be a major environmental problem in China, but information about effects on soils and waters is scarce. To contribute to increased knowledge about the problem a small catchment (about 7 ha) in the outskirts of Guiyang, the provincial capital of Guizhou in south-western China, was instrumented for collection of precipitation, throughfall, soil water and stream water. In addition soil samples have been collected and analyzed for key properties. Median pH in the precipitation is 4.40 (quartiles: 4.19 and 4.77) and the median sulfate concentration 228 µeq/L (quartiles: 147 and 334 µeq/L). The dry deposition of both SO₂ and alkaline dust is considerable. The sum of wet deposition of sulfate and dry deposition of SO₂ has been estimated to about 8.5 gSm⁻²yr⁻¹. The total S-deposition may be somewhat higher due to dry deposition of sulfate and occult deposition. In soil water, SO₄ ²⁻ is the major anion, generally ranging from 300 to 2500 µeq/L in the different plots. Calcium is an important cation, but there is also a considerable contribution of aluminum from the soil. In some of the plots the concentrations of inorganic monomeric aluminum (Ali) are typically between 200 and 400 µm. Potential harmful levels of aluminum and/or high Ali/(Ca²⁺ + Mg²⁺) molar ratios occur in the catchment, but damages to vegetation have not yet been reported. In most cases exchangeable aluminum accounts for between 75 and 95% of the total effective cation exchange capacity (CECE) in the mineral soils. The aluminum chemistry cannot easily be explained by conventional models as the Gaines-Thomas ion-exchange equation or equilibrium with an Al(OH)₃ mineral phase. The stream water is generally less acidic and has considerably lower concentrations of aluminum than the soil water, even though quite acid events have been observed (pH < 4.4). The median pH values are 4.9 and 5.0 in the two first order streams and 6.3 in the dam at the lower boarder of the catchment.
Afficher plus [+] Moins [-]On-line Analysis of Stack Gas Composition by a Low Resolution FT-IR Gas Analyzer
1998
Jaakkola, Petri T. | Vahlman, Tuula A. | Roos, Aappo A. | Saarinen, Pekka E. | Kauppinen, Jyrki K.
Stack gases of wood and oil burning boilers were analyzed by a low resolution FT-IR gas analyzer. Concentrations of carbon dioxide (CO₂), carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO₂), nitrous oxide (N₂O), hydrogen cyanide (HCN), sulfur dioxide (SO₂), methane (CH₄), and water vapor (H₂O) were predicted in real time by multicomponent analysis. Detection limits, linearity, analysis accuracy and long time repeatability were experimentally determined for selected gas components. Applicability of the measurement method was demonstrated by analysis of stack gas mixtures of known concentrations. The results indicate that all the primary stack gas components can be measured by the low resolution FT-IR gas analyzer with comparable results to single component measurement methods.
Afficher plus [+] Moins [-]Stability Studies of Waste Produced in Pilot-Plant Testing using Ferrous-EDTA and Magnesium-Enhanced Lime for Combined Sulfur-Dioxide/Nitrogen Oxides Removal
1998
Mendelsohn, M. H. | Livengood, C. D.
A pilot-plant-scale study of combined sulfur dioxide/nitrogen oxides (SO₂/NOₓ) removal has been performed by the Dravo Lime Company at the Cincinnati Gas and Electric Company's Miami Fort Station in North Bend, Ohio. This study used Dravo's patented Thiosorbic® lime process along with Argonne National Laboratory's (ANL's) patented process for combined SO₂/NOₓ removal using the chelate ferrous·ethylenediaminetetraacetate (Fe·EDTA). For approximately nine months, scrubbing tests were carried out, and waste samples were collected. Waste testing at ANL involved two types of long-term chemical stability experiments. In one test, the gas-phase composition above several different samples was studied by mass spectrometry over 22 months. Unexpectedly, production of carbon dioxide and hydrogen sulfide was observed in some of the samples. The other experiment involved solid-phase leaching. Samples were stored for up to 14 months before leaching. Each leachate was tested for total Kjeldahl nitrogen and for the nitrogen-containing ions nitrite, nitrate, and ammonium. Significant amounts of ammonium ions were found in two of the samples. Total leachable nitrogen was found to stabilize after about the first 7 months of storage.
Afficher plus [+] Moins [-]Geographic Classification of Heavy Metal Concentrations in Mosses and Stream Sediments in the Federal Republic of Germany
1998
Berlekamp, Jürgen | Herpin, Uwe | Matthies, Michael | Lieth, Helmut | Markert, Bernd | Weckert, Vera | Wolterbeek, H. Th. | Verburg, Tona | Zinner, Hans-Jürgen | Siewers, Ulrich
The results of the first German moss monitoring programme to estimate heavy metal pollution in the Federal Republic of Germany were combined with other large-scale investigations carried out in Germany and then classified geographically in a new form. Using Monte Carlo assisted factor analysis, six factors indicating sources of pollution were identified from the sets of element data from the moss monitoring project (As, Cd, Cr, Cu, Fe, Ni, Pb, Ti, V, Zn) and the data sets for SO₂ and particulate. The geographic distribution patterns of the factor values showed the regions in which the various sources are to be found. By combining the data the primarily anthropogenic chromium concentrations of the mosses were compared with the mainly geogenic chromium concentrations of the stream sediments in the form of examples. After normalization, the transformed chromium concentrations were transferred to a map of the entire area using inverse distance weighting. Anthropogenic and geogenic influences are being discussed on the basis of the results.
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