| Autor: |
Leppard, Gary G., Buffle, J., De Vitre, R. R., Perret, D. |
| Zdroj: |
Archiv für Hydrobiologie; September 1988, Vol. 113 Issue: 3 p405-424, 20p |
| Abstrakt: |
An iron-rich fraction was isolated from a small eutrophic lake and studied on a particle-specific basis by transmission electron microscopy (TEM) in conjunction with energy dispersive spectroscopy. The limnological context from which the iron-rich fraction was isolated was characterized using a combination of in situ probes and analytical chemistry. An iron-rich colloidal particulate was identified; three morphotypes occurred, two of which could be described as globular and one of which as near-globular in shape. The size range determined by TEM was 0.05—0.31 µm, with three quarters falling in the narrow range of 0.05—0.13 µm. The latter range was found to be more representative of the true particle size distribution than a distribution found by filtration alone, which suggested an average particle size greater than 0.45 µm. Among the entire population of these colloids, ca. 70 % contained iron whereas most of the remaining 30 % were rich in either Si or Ca. Amongst the iron-rich globules, 86.5 % were also rich in phosphorus and calcium. Some evidence was found to suggest that Fe/P/Ca-rich particles were occasionally associated with either Si or Si/Al; however, the major fraction of these particles was found to contain exclusively Fe, P and Ca. These new findings are presented in the context of the limnological phenomena documented at the site. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
