Refinar búsqueda
Resultados 1-4 de 4
Effects of nitrogen deposition on tree growth and soil nutrients in boreal scots pine stands
1998
Nissinen, A. | Hari, P. (Department of Forest Ecology, P.O. Box 24, University of Helsinki, 00014 Helsinki (Finland))
Influence of pH and Zinc Concentration on Cadmium Sorption in Acid, Sandy Soils
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.
Mostrar más [+] Menos [-]The environmental impact of shrimp aquaculture and the coastal pollution in Mexico
1998
Paez-Osuna, F. | Guerrero-Galvan, S.R. | Ruiz-Fernandez, A.C. (Estacion Mazatlan, Instituto de Ciencias del Mar y Limnologia, Universidad Nacional Autonoma de Mexico, Apdo. Postal 811, Mazatlan 82000, Sinaloa (Mexico))
Effect of organic materials on partitioning, extractability and plant uptake of metals in an alum shale soil
1998
Narwal, R.P. (Agricultural Univ. of Norway, Aas (Norway). Dept. of Soil and Water Sciences) | Singh, B.R.
