Die Einleitung von gereinigtem Abwasser in Seen

Treated wastewater discharged into a lake should be introduced below the trophogenic layer. Tracing the marked wastewater by echosounding revealed that the usual discharge method is unsuitable. The wastewater flows more or less to the depth of its own density, which is usually in the trophogenic layer. If there is no movement, that is, current in the water body, the wastewater accumulates at the pipe's mouth. A continuous current is therefore an indispensable prerequisite for a wastewater discharge site. It is only when wastewater is mixed with at least five parts of lake water that it does not rise more than two meters.     

Der Einfluss von gereinigtem Abwasser auf das Phytoplankton in Seen

The effect of domestic sewage effluents after a) mechanical, b) mechanical-biological and c) mechanical-biological-chemical treatment on algal cultures and on natural lake phytoplankton was studied by means of laboratory assays and in situ experiments. The concentrations of phosphorus and nitrogen are almost exclusively responsible for any algal growth. Other constituents which may be present in sewage effluents (e.g. residual amounts of iron originating from the tertiary treatment) do not stimulate substantially the growth of algae.     

Zur Frage der Karpfenintensivbewirtschaftung von Seen und Eutrophierung

Normally, carp rearing at medium densities is connected with the promotion of daphnia and filtration effects up to “clear-water states”. Therefore and because of the reduction of submerged plants and of the periphyton this form of carp rearing should be possible in eutrophic shallow lakes also at a slight nutrient introduction without any considerable eutrophication. Due to a deterioration of the light climate by re-suspension of the sediment even reductions of the primary production are possible. In the case of the Galenbeck lake a drastic reduction of submerged macrophytes occurred in connection with an increased development of plankton, only general estimations being available of the shares of macrophytes and phytoplankton in the overall production. The phytoplankton increase is are perhaps caused by the absence of filtrating zooplankton due to an insufficient reduction of the indigenous fish stocks. In the Galenbeck lake the structural changes of the ecosystem were due both to the high degree of re-suspension of the very mobile lime sediment and the absence of hard bottom areas, which made the total reduction of the macroflora possible.     

Denitrifikation von Stickstoffverbindungen in biologisch gereinigtem Abwasser der Faserplattenproduktion

The denitrification of biologically purified wastewater from the fibre-board production is investigated in the batch experiment in a laboratory reactor with and without addition of methanol (0.5 ml/l) as an additional source of carbon. Without addition of methanol, in the main only a reduction of nitrate to nitrite occurs, which accumulates. The rate of reaction is low, so that the process is not yet finished after 10 h. The addition of methanol leads to an acceleration of the reactions and to a full denitrification of the wastewater within 4 h.     

Zur Frage der Entstehung der luftelektrischen Unruhe

Zusammenfassung Es wird gezeigt, dass man bei der Untersuchung der luftelektrischen Unruhe auch die Lage der Station berücksichtigen muss, da der Jahresgang der luftelektrischen Unruhe an Flachlandstationen im Gegensatz zu dem Jahresgang der Leitfähigkeit ein Minumum im Sommer und ein Maximum im Winter aufweist, und somit eine ähnliche Entgegengesetztheit zu den Gebirgsstationen auftritt. Weiter wird der Zusammenhang der luftelektrischen Unruhe mit der Amplitude des Absolutwertes des Potentialgradienten, mit dem Wind, mit der Bewölkung und den verschiedenen Luttmassen untersucht. Abschliessend werden die im Geophysikalischen Observatorium bei Nagycenk (Ungarn) beobachteten Tages- und Jahresgänge der Häufigkeit der Unruhe in den verschiedenen Periodengruppen bzw. die Tagesgänge der vorherrschenden Periodengruppe diskutiert.

---

Summary It is shown, that the annual variation of atmospheric electric agitation has on field stations opposite to the annual variation of conductivity a minimum in summer and a maximum in winter, accordingly there is a similar opposition as on mountain stations. Therefore investigating atmospheric electric agitation it is necessary to take into consideration the situation of the observing place too. Further the connection of agitation with the amplitude of the potential-gradient and the wind, with sky cover and the different airmasses is examined. Finally the daily and annual variation of the occurence of agitation belonging to different frequency ranges and the daily variation of the prevailing frequency range observed in the Geophysical Observatory Nagycenk (Hungary) are discussed.

     

Zur Frage der inneren thermischen Unruhe des Meeres

Ohne Zusammenfassung     

Zur Modellierung der Adsorption von Mehrkomponentensystemen

Many dissolved organic compounds in waters and wastewaters can be effectively removed by adsorption processes. The design of such processes requires the modelling of adsorption equilibria in multi-solute systems. In this paper a review on the most useful equilibrium models for multicomponent systems of known and unknown composition is presented.     

Zur Kontrolle der Auswertung von Ionogrammen

Zusammenfassung 1. Pflüfung der Auswertbläter auf Widerspruchslosigkeit-2. Kontrolle mit grob-statistischen Methoden-3. Kontrolle gegen andere Stationen.

---

Summary 1. Test on self-consistency of scaling-2. Test with rough statistical methods-3. Test against distant stations.

---

---

Ionosphären-Institut Breisach im Fernmeldetechnischen Zentralamt der Deutschen Bundespost,Breisach/Rh.

---

In Klammern werden die üblichen Code Nummern gegeben.     

Zur Wirkung von Singulettsauerstoff bei der Wasseraufbereitung

On the laboratory scale investigations are carried out into the action of singlet oxygen, which is generated in water by addition of sodium-hypochlorite and hydrogen-peroxide solution, on Elbe river water and model waters. DOC does not change; COD, however, decreases considerably. The advantages and drawbacks of the treatment are stated.     

Karpfenintensivbewirtschaftung von Seen und Eutrophierung

In the Galenbeck lake, a shallow lake covering 700 ha and having a nutrient load of 0.23 g/m²a P as well as 4.3 g/m²a N, in 1965 a stock of carp of 500 animals/ha was established and additionally fed with grain. This stock of carp resulted in a considerable whirling-up and redeposition of the soft lime sediments, the rich submersed vegetation disappeared and the phytoplankton reached maxima of 885,420 cells/ml, whereas the zooplanktion reached only 4530 ind./l. The chlorophyll contents increased to 464 mg/m³, the depth of visibility decreased to 10 cm. The total planktonic primary production is estimated at 500 g/m²a C at least. These changes are regarded as eutrophication, its cause being attributed mainly to the internal fertilization by an intensified recirculation of nutrients from the sediment, but also by the fertilization which is connected with feeding. When the fish rearing had ceased and the stock of carp had been fished off, in 1970 a reacreation of the lake began, and in 1974 the lake reached again its original state as a clear-water lake with an abundant contents of macrophytes, supported also by the P-retention in an upstream storage reservoir for spray-irrigation water.