Die Anwendung einer Fourier-Transformation zum Ausgleich von Saisonschwankungen bei der physikalisch-chemischen Charakterisierung von Fliessgewässern

The calculation of the mean y₀, the amplitude A, and the phase t₀ of the periodic regression function y(t)=y₀+(A/2)sin[(t−t₀)2π/T] is shown for the case of known period length T. An error estimation gives valuable information on how to plan efficient research programs. The theory is exemplified using stream temperature measurements. Applicability of the method to other limnological data, such as oxygen content is briefly discussed.      

Anwendung synthetischer kationenaktiver Polyelektrolyte zur Abwasserreinigung in der Erdölindustrie

From polychlorinated paraffins (C = 13 … 19) cation-active products are obtained on a bench scale by conversion with ethylenediamine and subsequent quaternization with dimethyl sulphate. The cation-active products are investigated with respect to their efficiency in the coagulating flotation of wastewaters of the petroleum industry. The content of petroleum-containing products, the value of COD-Cr as well as turbidity and colouration are reduced by up to 90, 67 and 86%, respectively. These results are almost equivalent to those of a commercial flocculant, which was used by comparison, and considerably exceed the results of FeSO₄.     

Die Anwendung von Clusteranalysen zum Mustervergleich – BASIC-Programmierung der Potentialmethode CLUPOT

The method of cluster analysis as a means for the structuring, classification and interpretation of multivariate data is represented in a survey of hierarchical and non-hierarchical procedures. The non-hierarchical potential method CLUPOT is described in a BASIC program and applied to the example of the daily variations of the heavy-metal concentrations in wastewater.     

Die Anwendung von Kompostierten Siedlungsabfällen

Ohne Zusammenfassung     

Kontamination mit coliformen Keimen durch Insektenlarven bei der Aufbereitung von Trinkwasser

Contamination of Drinking Water with Coliform Organisms by the Larves of Gnats in the Water Treatment Plant E. coli and coliform organisms are used to judge the microbial quality of drinking water. The presence of these organisms in water indicates that there is a risk for faecal oral transmitted pathogen organisms. E. coli shows the faecal contamination of men and warm blooded animals (mammalian and birds), coliform organisms may be excreted as well from cold blooded animals. The cold blooded animals normally don’t excrete pathogen organisms relevant for human beings. So coliform organisms don’t have such a high relevance for drinking water microbiology. In this paper an incident is presented with a contamination of drinking water with coliform organisms in the treatment plant by the larves of gnats. The larves of the gnats crawl into the treatment chamber via entrance for ventilation. The larves were kept back on the surface of the filters but they contaminated the water with coliform organisms.     

Die Berücksichtigung des Kanalspeicherraumes bei der Bemessung von Regenwasserkanalisationen

Zusammenfassung Es werden drei Verfahren n?her untersucht, welche zur Bemessung von Regenwasserkanalisationen den sogenannten Kanalspeicherraum zu berücksichtigen versuchen. Die Verfahren vonMüller-Neuhaus undGruhler k?nnen wegen Unzul?nglichkeiten in den Annahmen neben den bew?hrten Fliesszeit-und Summen-linienverfahren nicht bestehen. Das italienische Verfahren eignet sich wegen der schwierigen Berechnung des Wasserinhaltes im Kanalnetz nicht zur praktischen Dimensionierung. Da zudem die Voraussetzungen aller ?Speicherverfahren? mit den festgelegten überschreitungsintervallen der Regenintensit?ten unvertr?glich sind, ist ihre Anwendung nicht gerechtfertigt.

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Summary Three methods for the dimensioning of storm water sewers have been investigated which emphasize the storage volume of the sewers. Due to inadequate assumptions, the methods proposed byMüller-Neuhaus andGruhler proved to be inapplicable and cannot replace the hitherto used rational method and ‘Summenlinienverfahren’. The Italian method based on the difficult evaluation of the water volume within the sewerage system is too complicated for practical use. Furthermore, all calculation methods considering the storage capacity are based on assumptions which are incompatible with the chosen design value of the recurrence interval of the rainfall intensities. Their application is not recommended.

     

Die praktische Anwendung der elektrochemischen Sauerstoffbestimmung im Wasser

Zusammenfassung Zum Betrieb der früher beschriebenen Oxytester-Sonde [2] wurde ein Transistorger?t entwickelt zur Messung von Temperatur, Sauerstoffgehalt und Leitf?higkeit des Wassers. Die Stromversorgung erfolgt aus eingebauten Stahl-Akkus, welche mit einem ebenfalls eingebauten Gleichrichteraggregat immer wieder nachgeladen werden k?nnen. Das Ger?t kann gleichzeitig als vollwertiger Labor-Leitf?higkeitsmesser und als Labor-Fernthermometer eingesetzt werden. DieTemperaturmessung mit Thermistoren ist ausgebaut für Direktablesung der Temperatur an einem dreistelligen Z?hlwerk (Helipot-Digidial), ebenso die Messung deselektrischen Widerstandes. Diespezifische Leitf?higkeit kann direkt abgelesen werden; die Konstante der Messzelle wird in die Messbrücke eingeeicht. Kabelwiderstand und-kapazit?t sind kompensiert. Die Anzeige des Brückensignals wird zweistufig verst?rkt und ist hochempfindlich. DerSauerstoffgehalt kann wahlweise nach dem Verfahren vonT?dt (ohne extern zugeführte Hilfsspannung) oder polarometrisch (mit dem gleichen Elektrodenpaar aus Gold und Zink) gemessen werden.

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Summary In an earlier publication [2] we described a probe (oxytester) for the combined and remote measurement of temperature, conductivity and oxygen content of water. The present paper describes an improved instrument for the probe that is fully transistorized and powered by nickel-cadmium batteries which can be recharged with a built-in rectifier. Watertemperature is measured with the aid of thermistors and directly indicated on a 3-digit counter (Helipot Digidial). The same applies for theelectrical resistance. Specific conductivity can also be read directly from the instrument, because the circuits are precalibrated and resistance and capacity of the cable compensated. Amplification of the signal renders the instrument highly sensitive.Oxygen content of the water can be measured either by T?DT's method (without auxiliary voltage) or polarometrically (with the same zinc and gold electrodes). The instrument has been designed for routine use in limnological research, and for industrial control of water conditions. It is being manufactured in Switzerland.

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Herrn Prof. Dr. O. Jaag zum 60. Geburtstag herzlich zugeeignet!     

Hygienische Aspekte bei der Behandlung und Beseitigung von Klärschlamm und anderen festen Abfallstoffen

Ohne Zusammenfassung     

Einige Probleme bei der Anwendung des MPN-Verfahrens zur quantitativen Salmonellenbestimmung

So far, the MPN technique has been the method chosen for detecting pathogenic bacteria in waters, since it allows us to use larger volumes. In the evaluation, however, comparatively frequently (10 … 15%) nontypical codes occur. The validity of the Poisson model is confirmed for pure cultures by extensive laboratory experiments with pure cultures and controlled mixed cultures. In mixed cultures, however, a comparatively large number of atypical codes occur, since obviously a single organism is not sufficient for the formation of a growth-cover on the test tube, so that the true number of germs may be considerably underestimated. Obviously, the accompanying flora has an inhibiting effect on the salmonella detection.