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Comparison of selected element concentrations in tall and short forms of Spartina alterniflora
1998
Ornes, W.H. | Sajwan, K.S. | Loganathan, B.G. | Chetty, C.S. (Department of Biology and Geology, University of South Carolina, Aiken, SC 29801 (USA))
Effects of nesting yellow-legged gulls (Larus cachinnans pallas) on the heavy metal content of soils in the Cies Islands (Galicia, North-West Spain)
1998
Perez, X.L.O. (Departamento de Edafoloxia e Quimica Agricola, Facliltade de Bioloxia, 15 706 Santiago de Compostela (Spain))
Occurrence of persistent organic contaminants and related substances in Hong Kong marine areas: an overview
1998
Connell, D.W. | Wu, R.S.S. | Richardson, B.J. | Leung, K. | Lam, P.S.K. | Connell, P.A. (Centre for Environmental Science and Technology, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China))
Comparisons and temporal trends of organochlorines and heavy metals in fish from the Gulf of Bothnia
1998
Vuorinen, P.J. | Haahti, H. | Leivuori, M. | Miettinen, V. (Finnish Game and Fisheries Research Institute, P.O. Box 6, FIN-00721, Helsinki (Finland))
Arsenic in Human and Cow's Milk: a Reflection of Environmental Pollution Texte intégral
1998
Ulman, Cevval | Gezer, Semra | Anal, Özden | Töre, I Ruhi | Kirca, Üzeyir
Arsenic, an environmental pollutant, is present in minute but invariable amounts in food, drinking water and ambient air. Izmir is founded on a land of long extinct volcanoes, with vast areas of lava ground suitable for agriculture. It is located at close vicinity to high thermal activity, e.g., hot springs and thermal baths. In the present study, total arsenic level in breast milk was assessed in randomly chosen 35 lactating women of different socioeconomic levels who live downtown in Izmir and in milk of 36 cows grazing on shoulder grass of highways with heavy traffic. Total arsenic was assessed on an atomic absorption spectrophotometer (AA-680 Shimadzu). Mean (± SEM) arsenic was found to be 4.219 ± 0.079 µg L⁻¹ in breast milk, and 4.932 ± 0.38 µg L⁻¹ in cow's milk. Conclusion: in Izmir, arsenic contamination of breast milk was not found so as to be considered noxious for suckling infants, whereas was found relatively higher in cow's milk. It would be prudent to remember breast and cow's milk arsenic contamination in breast fed or milk fed babies living in areas with higher thermal activity or in regions where ground water is with high arsenic content.
Afficher plus [+] Moins [-]Influence of pH and Zinc Concentration on Cadmium Sorption in Acid, Sandy Soils Texte intégral
1998
Wilkins, B. J. | Brummel, N. | Loch, J. P. G.
Batch adsorption experiments were carried out with samples from an A-, Bh- and C-horizon of contaminated sandy soil of podzolic character from the Kempen region at the Dutch-Belgian border. Cadmium sorption was studied on 3 soil samples at 3 different pH-levels (3.6, 4.3 and soil buffered pH) and 3 different additions of zinc (0–40 mg l⁻¹).Adsorption of cadmium by acid sandy soils can be fitted by a Freundlich adsorption isotherm. Although zinc competes with cadmium for the sorption sites, we observe a two to three times stronger competition effect of the proton cation, which is explained by the chemical properties of both ions. The cadmium adsorption coefficient KF decreases considerably by an increase of the proton activity used in the sorption experiments. Organic matter content explains for a large part the variation of KF of te three soil samples. Desorption data do not fit the proposed regression model for adssorption. Not all the cadmium, intitially present in the polluted soil, will fylly desorb reversibly. Thus, part of the cadmium may be irreversible bound.
Afficher plus [+] Moins [-]Influence of the Soil Solution Composition on Retention and Release of Sulfate in Acid Forest Soils Texte intégral
1998
Kaiser, K. | Kaupenjohann, M.
The potential for sulfate retention is an important soil feature for buffering of atmospheric acid deposition. We studied the effects of increasing additions of different neutral salts and acids on mobilization and retention of SO₄ ²- in acid forest soils. Soils containing up to 11 mmol SO₄ ²- kg⁻¹ were equilibrated with H₂O, NaCl, MgCl₂, and HCl. Release of SO₄ ²- was highest with H₂O and NaCl additions and lowest when HCl was used. Increasing the ionic strength of the added solutions caused decreasing SO₄ ²- concentrations in equilibrium solution. Decreasing pH in equilibrium solution was found to be the reason for the decrease in release. Even when the pH was < 4, the SO₄ ²- release decreased. We assume that this finding resulted from the fact that in the soils studied the SO₄ ²- sorption was controlled by the high contents of Fe oxides/hydroxides.Experiments with Na₂SO₄, MgSO₄, and H₂SO₄ demonstrated that the B horizons already containing high amounts of SO₄ ²- were still able to retain SO₄ ²-. Sulfate retention increased in the order Na₂SO₄ < MgSO₄ < H₂SO₄, which corresponds to increasing H⁺ availability. The higher SO₄ ²- retention along with MgSO₄ compared to Na₂SO₄ may be caused by higher potential of Mg to mobilize soil acidity compared to Na.
Afficher plus [+] Moins [-]Bacterial Biodiversity in Soil with an Emphasis on Chemically-Contaminated Soils Texte intégral
1998
Trevors, J. T.
Microorganisms isolated from soil are sources of known and new microorganisms and genetic material. This review examines general principles of soil bacterial biodiversity, limitations in sampling soils, and examples of bacterial diversity in chemically-contaminated soils. Both conventional and molecular methods used to assess microbial biodiversity in soils will be addressed as well as selected examples of the effects of organic and inorganic pollutants on soil microbial diversity.
Afficher plus [+] Moins [-]Organochlorine Contamination in Selected Estuarine and Coastal Marine Finfish and Shellfish of New Jersey Texte intégral
1998
Kennish, Michael J. | Ruppel, Bruce E.
Analysis of PCB, DDT, and chlordane contamination in selected finfish and shellfish species from estuarine and coastal marine waters of New Jersey (U.S.A.) indicates consistently highest organochlorine contaminant levels in samples from the north and northeast regions of the state in proximity to industrialized sites. Gas chromatographic analysis of tissue samples from three finfish species (bluefish, Pomatomus saltatrix; striped bass, Morone saxatilis; weakfish, Cynoscion regalis) and one shellfish species (blue crab, Callinectes sapidus) collected throughout the state during the 1986–1987 and 1988–1991 sampling periods revealed mean PCB, DDT, and chlordane concentrations ranging from 200–5, 380 µg g⁻¹ wet weight, 25.14–492.52 µg kg⁻¹ wet weight, and 5–106.44 µg kg⁻¹ wet weight, respectively. A major conclusion of this study is that some commercially and recreationally important finfish and shellfish species in New Jersey waters, especially those which are lipid-rich, have continued to accumulate PCBs, DDTs and chlordane from the environment long after restrictive regulations were first placed on their use in the United States during the 1970s. The greatest impact of organochlorine contamination is nearby urban centers, most notably Newark and New York City.
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 Texte intégral
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.
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