Showing papers by "Brit Salbu published in 1990"
TL;DR: In this article, the degree of binding or association between deposited radionuclides (137Cs,134Cs and 90Sr) and components in soil was investigated, and the results indicated that a major fraction of the radiocesium is associated strongly with organic and mineral materials in the litter or upper soil layers.
Abstract: Measurements performed in 1986–1988 demonstrate that most of the radiocesium isotopes (137Cs and134Cs) deposited after the Chernobyl accident are still located in the upper soil layers (0–2 cm). The vertical migration appears to be slow, and only a small fraction of the radiocesium has been transferred into the biological cycle. Sequential extraction techniques have been utilized in order to investigate the degree of binding or association between deposited radionuclides (137Cs,134Cs and90Sr) and components in soil. The results indicate that a major fraction of the radiocesium is associated strongly with organic and mineral materials in the litter or upper soil layers: less than 10% is easily leachable. The distribution of137Cs throughout the fractions was similar to that determined for naturally occurring stable cesium (133Cs), implying that isotopic exchange had been extensive. For90Sr, the results show a relatively high leachable fraction. Therefore, present results indicate that radiocesium should be less mobile, and less available for root uptake, than90Sr in soil.
116 citations
TL;DR: In this article, identical solutions of inorganic Al (400, 600, and 800 μg Al L−1) were stored for 1 mo at either 2 or 25 °C.
Abstract: Temperature affects the solubility of Al(OH)3(s), the solubility product formed, the hydrolysis and molecular weight distribution of aqueous Al species as well as the pH of the solutions. In the present work, identical solutions of inorganic Al (400, 600, and 800 μg Al L−1) were stored for 1 mo at either 2 or 25 °C. In the solutions stored at 25 °C pH varied from 4.83 to 5.07, while in the corresponding solutions stored at 2 °C pH varied from 5.64 to 5.78. In spite of the relatively low pH at 25 °C, significant amounts of high molecular weight Al species were precipitated from the solution and the solubility product (log*K s ) of (Al(OH)3) (s) was low (9.0). Substantial amounts of high molecular weight Al species were also formed at 2 °C, but the majority was present as colloids in the solution. The solubility product (converted from 2 into 25 °C) was 10.2, reflecting a solubility product of an amorphous (Al(OH)3)(s) phase. The different physico-chemical forms of Al present at 2 and 25 °C should have relevance for water/soil chemistry modeling.
55 citations
TL;DR: In this article, Colloids play a major role in the transport of trace metals as well as radionuclides in natural waters and are of importance for passive take in biota.
Abstract: Colloids play a major role in the transport of trace metals as well as radionuclides in natural waters. These species are of importance for passive take in biota.
17 citations