Möglichkeiten der Nachreinigung von Abwässern aus der Kunstlederproduktion mit Hilfe von Algen,Teil 2

The attempt was made to use the alga Scenedesmus quadricauda for the purification of wastewaters from the production of artificial leather. The dimethylamine contained in these wastewaters is continuously decomposed and the remaining nitrogen-containing residuals are used as a nutrient source for the production of algal biomass. In continuous experiments with original wastewaters, dimethylamine and its metabolites showed a pronounced inhibiting effect. In practice, a longer retention time in the reactors as well as a sufficient share of municipal wastewater are required in order to avoid a limiting of growth due to a phosphorus deficiency. The second part of this paper is concluded by information about other investigations performed by us on the purification of artificial leather wastewaters with the aid of the biological nitrogen elimination under specific conditions with a successful denitrification of up to 95%.     

Zum Umweltverhalten von Fluortensiden. Teil 3: Reinigung der industriellen Abwässer

Four fluorotensides which are used mainly industrially are investigated with respect to their removability from waters. Since, in general, fluorotensides are difficult to remove or not at all removable biochemically, the effects of chemical or physicochemical treatment processes are tested. As the results represented in pictures and tables show, different modes of behaviour can be recognized with respect to the respective purification effect for the investigated fluorotensides, partly among them. Flocculation with Al- and Fe-salts as well as chlorination and ozonization show only partial effects. But all the investigated fluorotensides can be adsorptively eliminated by means of powder or granular active charcoal and adsorbent resin Wofatit EA₆₀.     

Zur Analytik von Chlorphenoxyalkansäuren und Chlorphenolen. Teil 2: Nachweis von Chlorphenoxyalkansäuren und Chlorphenolen in der Fischgalle

The bile liquid is preserved with ethanol and the protein is precipitated. Prefractionating is done by liquid-liquid extraction by chloroform and ethyl acetate. The extracts are column-chromatographically separated on Florisil and subsequently detected by thin-layer chromatography. For determining the identity of substances, the penta fluorobenzyl derivatives are prepared and chromatographed under the same conditions. Detection is carried out with the aid of ammoniacal silver nitrate reagency and ultraviolet irradiation. The highly polar conjugates of chlorophenoxyalkane acids and chlorophenols which are present in the bile are cracked by acid hydrolysis and then cleaned by re-extraction. In this way, 2, 4-D, MCPA, MCPP, 2,4-dichlorophenol and 2-methyl-4-chlorophenol were detected from Salmo gairdneri. 6… 21 d after the application of the herbicides in the catchment area their concentration in the fish bile amounted to about 200 mg/l, 90% of them having been conjugates. Thus, the biliary excretion of xenobiotic substances offers an important new aspect of biomonitoring by means of fish tests, especially in the range of subacute and chronic toxicity.     

Nährstoffbelastung und Trophie von Talsperren der DDR Teil 1: Einzugsgebietsstruktur und Nährstoffsituation

Statistically secured relations between nutrient concentrations in the water and characteristics of the catchment areas can be proved for the storage reservoirs of the GDR. The o–PO₄ concentration during the full overturn in spring shows a close relation to the population density of the catchment area. Existing differences of concentration between drinking-water and industrial-water storage reservoirs can be attributed to different degrees of worthiness of protection of the catchment areas and to differences of the water morphology. The NO₃ concentration is closely correlated with the proportion of agriculturally used area in the catchment area. The mass ratio NO₃–N: o–PO₄–P mostly lies above the limiting range of the limitation of nitrogen (> 12: 1), so that phosphorus becomes the central quantity of a possible control of the trophic level. Especially for drinking-water storage reservoirs in the weakly eutrophic range the reduction of the P-load is necessary and it has a high trophy-improving effect here.     

Untersuchungen zur Einzel- und Gemischadsorption von Phenolen an Aktivkohlen. Teil 3: Zur pH-Abhängigkeit der Adsorptionsgleichgewichte

In order to describe the adsorption of dissociating substances, initially the adsorption isotherms for the borderline cases of undissociated and dissociated substances are experimentally determined. With the aid of the Ideal Adsorbed Solution Theory (IAS Theory) then the calculation is successfully performed for pH-values at which both forms are present side by side. As examples, the systems phenol/activated carbon and p-chlorophenol/activated carbon are examined, and they show a good agreement between calculation and measurement.     

Zum Umweltverhalten von Fluortensiden. Teil 2. Untersuchung der biochemischen Abbaubarkeit

In continuation of a publication on the behaviour of fluorotensides in aqueous solution there were tested four selected fluorotensides, among them a noniononic ethoxylated substance and three anion-active substances, in two different equipment with respect to their biochemical degradability. The BOD₅, the potassium permanganate consumption, the dry matter contents and the loss on ignition as well as the dehydrogenase test were used as parameters for judging the degradation behaviour. In all the four cases a high biochemical stability was found, so that they must be classified into the group C “biochemically not degradable or difficult to degrade” in agreement with the results found, according to the water pollutants catalogue.     

Über die Entfernung von Schwermetallionen aus Betriebsabwässern durch Ultrafiltration. Teil 2. Theoretische Fundierung der gewonnenen Erkenntnisse an Modellösungen unter Zusatz von Komplexbildnern

Possible formulae of complex compounds of copper and polyacrylic acid as well as polysulfonic acid are demonstrated. The formal complex dissociation constants of the complexes with copper and acrylic acid are developed. The actual concentration of unbonded copper ions under different media conditions are calculated in terms of the formal complex dissociation constants of the most important complex compound for ultrafiltration consisting of one copper ion and two acrylic acid monomer units. As a result follows the theoretical retention capacity of membranes and the underlying limit of the concentration of metal ions for the economical application of ultrafiltration. Most of the experimental findings in the first part have been given their theoretical foundation.     

Kurzzeitermittlung der Ablaufqualität von Belebtschlammanlagen anhand der Atmungsaktivität

For checking the quality of the effluent from an activated sludge plant for waste-waters from the sulphite pulp production the respiration of an activated sludge sample in air-saturated water is determined initially without the addition of substrate (ground respiration) and after that with an addition of substrate (methanol, substrate respiration) by means of the Clark-electrode. The measuring device is designed by means of zero displacement in such a way that the difference of the oxygen concentration is indicated by a time relay as the difference quotient. Between the ground respiration and the effluent concentration of BOD₅ exists a significant positive regression, which can be used for controlling the plant. The determination of the substrate respiration serves only for checking with respect to perhaps given inhibition of the conversion of matter by the activated sludge. The determination of the activity of the activated sludge sample takes only 20 min; inclusive of the required determination of the dry matter of sludge, the technique provides a well reproducible measured value for the biochemical conversion in the activated sludge plant within 1… 1.5 h.     

Zum Umweltverhalten von Fluortensiden Teil 1: Prüfung auf Aquatoxizität

Poecilia reticulata PETERS (guppy) and the green alga Monoraphidium griffithii were used for testing of different fluorotensides. After the representation of the methods of investigation and the definition of criteria of toxicity the obtained results of investigation are discussed. In general, the toxicity of the four investigated fluorotensides to algae was lower than to fish. The anionic fluorotenside CF₃—(CF₂)n—CFH—COONa was an exception. In tables and diagrams the results are summarized. Finally, for the condition of the receiving-water biocenosis class “2” the respective still permissible matter concentrations are proposed. They vary between 0.05 and 0.2 mg/1.     

Gewinnung biokinetischer Daten von Altwässern mit dem Respirationsfermentor. Teil 1: Methodische Grundlagen und die Bestimmung der spezifischen Wachstumsund Sauerstoffaufnahmerate

Es wird eine Fermentationsvorrichtung für die Messung des Sauerstoffverbrauchs bei wählbaren Sauerstoffpartialdrucken vorgestellt, die in einem geschlossenen Gaskreislauf einen Laboratoriumsfermentor mit Meß- und Regeleinrichtungen sowie Möglichkeiten der Probenahme aufweist. Die Druckregression durch die Kohlendioxidadsorption steuert die synchron registrierte Nachlieferung von Sauerstoffgas. Durch diskontinuierliche Kultivation eines adaptierten Belebtschlammes wurden von einem Braunkohlenpyrolyseabwasser die Sauerstoffverbrauchskurven aufgenommen. Es wurde ein polyauxischer Kurvenverlauf erhalten, wobei auf den Abbau der niederen Fettsauren, im wesentlichen Azetat, 70 … 80% des Gesamtsauerstoffverbrauchs entfielen. Hierfür werden biokinetische Daten bestimmt; ; ; μ_max = 0,56 h^–1 (ausgewählte Werte). Die bei der Erfassung und Errechnung der Daten auftretenden Probleme wurden diskutiert.