خيارات البحث
النتائج 211 - 220 من 347
Residues of chlorinated hydrocarbon insecticides in human milk of Jordanian women
1998
Nasir, K. | Bilto, Y.Y. | Al-Shuraiki, Y. (Department of Biological Sciences, University of Jordan, Amman (Jordan))
Heterogeneous reactions of halogen containing species on sulfuric acid aerosol mimics النص الكامل
1998
Beichert, P. | Schrems, Otto
Environmental contaminants in tissues of a neonate St Lawrence beluga whale (Delphinapterus leucas)
1998
Gauthier, J.M. | Pelletier, E. | Brochu, C. | Moore, S. | Metcalfe, C.D. | Beland, P. (Trent University, Environmental and Resources Studies Program, Peterborough, Ontario K9J 7B8 (Canada))
California sea lion (Zalophus californianus) populations and SIGMA DDT contamination
1998
O'Shea, T.J. | Brownell, R.L. Jr. (US Geological Survey, Biological Resources Division, Midcontinent Ecological Science Center, 4512 McMurry Avenue, Fort Collins, Colorado 80525-3400 (USA))
Chlorinated hydrocarbons in marine sediments of the Baja California (Mexico)-California (USA) border zone
1998
Gutierrez-Galindo, E.A. | Mendoza, L.M.R. | Munoz, G.F. | Celaya, J.A.V. (Instituto de Investigaciones Oceanologicas Universidad Autonoma de Baja California, P.O. Box 2516 Ensenada, Baja California (Mexico))
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))
Influence of the Soil Solution Composition on Retention and Release of Sulfate in Acid Forest Soils النص الكامل
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.
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