Showing papers by "Swiss Federal Institute of Aquatic Science and Technology published in 1976"
01 Sep 1976
TL;DR: In this paper, a model for the distribution of the metals between biomass, allochthonous material and dissolved phase was employed, and a metal balance was made for the Lake of Alpnach.
Abstract: In the mesotrophic Lake of Lucerne (Bay of Horw) and in the eutrophic Lake of Alpnach concentration and sedimentation of iron, copper, zinc, cadmium and lead were investigated as a function of time and depth, and compared with a series of physical and chemical parameters. A metal balance was made for the Lake of Alpnach. A model for the distribution of the metals between biomass, allochthonous material and dissolved phase was employed. Phenomenology and model lead to the following conclusions: the sedimentation of the metals is dominated by allochthonous particles, the biogenic particularization is partially reversed by lake internal decomposition processes and the trace metals reaching the sediment are partially redissolved.
24 citations
01 Mar 1976
TL;DR: In this article, it was shown that in eutrophic shallow lakes, the nutrient supply to the trophogenic layer by the sediments can exceed temporarily the external loading by more than a hundredfold.
Abstract: This study shows that it is possible to restore a highly eutrophic lake by the mean of bottom water siphoning. The main effects of the hypolimnion drainage, such as, erosion of the hypolimnion and increase of the nutrient export out of the lake are discussed. From mass balance calculations it is deduced that in eutrophic shallow lakes the nutrient supply to the trophogenic layer by the sediments can exceed temporarily the external loading by more than a hundredfold. The process of a lakes selfmaintaining auteutrophication is described. An extended summary in English is given at the end of the paper.
22 citations
01 Sep 1976
TL;DR: In this paper, the effects on phytoplankton photosynthesis of inorganic metal salts HgCl2, CuSO4, Cd(NO3)2, ZnCl2 and PbCl2 were studied over monthly intervals.
Abstract: The effects on phytoplankton photosynthesis of inorganic metal salts HgCl2, CuSO4, Cd(NO3)2, ZnCl2 and Pb(NO3)2 were studied over monthly intervals.
20 citations
TL;DR: In this paper, an investigation into the behavior of aromatic hydrocarbons in chlorinated water is described. Aromatic fractions of diesel fuel were exposed to highly chlorinated waters for definite periods of time (1, 30 and 70 h) and the extracts were subjected to gas chromatographic analysis.
17 citations
TL;DR: In this paper, a Vorschrift fur die Bestimmung niedriger carbonsaurekonzentration (ppb*-Bereich, C1−C24 Carbonsauren) aus wasrigem Milieu mittels Kapillar-Gas-Chromatographie gegeben.
Abstract: Es wird eine Vorschrift fur die Bestimmung niedriger Carbonsaurekonzentration (ppb*-Bereich, C1−C24 Carbonsauren) aus wasrigem Milieu mittels Kapillar-Gas-Chromatographie gegeben. Die praktische Anwendung wird an einer Phenylcarbonsauremischung, einer Abwasser-und Faulschlammwasserprobe gezeigt.
9 citations
01 Sep 1976
TL;DR: In this paper, a predictive mechanistic nitrification model for rivers is developed and discussed, which is applicable in rivers with small hydraulic radii (< 1 m) and reasonable flow velocities (∼ 1m/sec).
Abstract: Cumulative frequency distributions of ammonium concentrations in Swiss rivers demonstrate that today ammonium standards are exceeded in relatively small rivers only. A predictive, mechanistic nitrification model for rivers is developed and discussed. The model is applicable in rivers with small hydraulic radii (<1 m) and reasonable flow velocities (∼1m/sec). In a case study for the river Glatt the model is applied (verified) and used as a predictive tool.
8 citations
01 Mar 1976
TL;DR: In this article, the heavy metals Fe, Mn, Cd, Cr, Cu, Pb and Zn were determined in the vertical profiles of Lake Constance (Obersee and Untersee) and Greifensee by means of atomic absorption spectrometry.
Abstract: Monthly measurements were made over a one-year period to determine the heavy metals Fe, Mn, Cd, Cr, Cu, Pb and Zn in the vertical profiles of Lake Constance (Obersee and Untersee) and Greifensee, by means of atomic absorption spectrometry. Fe and Mn exhibited the usual cyclical fluctuations depending on redox conditions in the hypolimnion. For Cd, Cr, Cu, Pb and Zn no concentration patterns were noted that would show their dependency on seasonal and vertical stratifications.
1 citations
01 Mar 1976
TL;DR: In this article, an improved method for the determination of ATP in lakewater is described, which is usefully applied in limnological routine analyses by deep freezing filter residue samples in liquid nitrogen, which can then be transported to the laboratory.
Abstract: An improved method for the determination of ATP in lakewater is described. The process can be usefully applied in limnological routine analyses by deep freezing filter residue samples in liquid nitrogen, which can then be transported to the laboratory. Possible sampling and processing errors are discussed.