bluuebunny/crossref_metadata_2025_split huggingface dataset:
Der Einfluß der landwirtschaftlichen Nutzung von Talsperreneinzugsgebieten auf den Nährstoffeintrag in Trinkwassertalsperren
Authors: Wegener U. , Dörter K. , Beuschold E. 
Published: February 2007

AbstractIm Einzugsgebiet der Rappbode‐Talsperre, Harz, wurde an Hand von Parzellen‐ und Großflächenversuchen die Größenordnung des Nährstoffabtrages unter verschiedenen natürlichen und unterschiedlichen Bewirtschaftungsbedingungen untersucht. Der Nährstoffabtrag naturnaher Einzugsgebiete schwankte für Phosphor von 0,21… 0,70 kg P/ha. a und für Stickstoff von 2,9… 11,8 kg N/ha. a. Dagegen wurden aus einem intensiv genutzten Gebiet Nährstoffabträge von 1,10 kg P/ha. a und 26,0 kg N/ha. a gemessen. Zur Verminderung des Nährstoffabtrages werden Maßnahmen des Erosionsschutzes und der landwirtschaftlichen Düngung vorgeschlagen.Weiterhin wird nachgewiesen, daß der Einfluß der Landwirtschaft im vorwiegend bewaldeten Einzugsgebiet der Rappbode‐Talsperre geringer ist als in anderen Einzugsgebieten. Je landwirtschaftlich genutzter Flächeneinheit ist der Nährstoffabtrag jedoch relativ hoch, wobei besonders bei Stickstoff eine steigende Tendenz zu erwarten ist.Auf wasserwirtschaftliche Maßnahmen zur Verminderung des Nährstoffeintrages in die Talsperre, so zum Beispiel durch den Bau von zusätzlichen Vorsperren, wird verwiesen.
Atomabsorptionsspektroskopische Bestimmung von Eisen, Kupfer, Zink, Cadmium, Mangan und Kobalt in Natur‐ und Brauchwässern mit der “Injektionsmethode” nach vorhergehender extraktiver Anreicherung
Authors: Gläser E. 
Published: February 2007

AbstractIn der Industrie, der Wasserwirtschaft und im Umweltschutz sind zunehmend in Wässern Schwermetallgehalte von wenigen μg/l zu bestimmen (MARGULOVAet al.;WELZ). Kolorimetrische Verfahren sind in diesem Konzentrationsbereich sehr arbeitsaufwendig und stellen hohe Anforderungen an die manuellen Fertigkeiten des Laboratoriumspersonals. Die Atomabsorptionsspektroskopie bietet eine zeit‐ und kostengünstige Alternative. Allerdings muß hier eine extraktive Anreicherung vorgeschaltet werden. Besonders günstig ist, gleichzeitig mehrere Metalle zu extrahieren und diese im gleichen Extrakt nacheinander zu bestimmen. Um trotz hoher Anreicherungsfaktoren nicht unhandlich große Wassermengen ausschütteln zu müssen, wird zur atomabsorptionsspektroskopischen Endbestimmung die sog. “Injektionsmethode” (SEBASTIANI, OHLS undRIEMER) angewendet, für die Probemengen von 0,1 ml je Bestimmung ausreichend sind.
Beitrag zur Aufbereitung arsenhaltiger Schachtwässer zu Trinkwasser. Teil 2: Ergebnisse kleintechnischer Versuche
Authors: Röske I. , Kermer K. 
Published: February 2007

AbstractDie Aufbereitung schwach arsenhaltiger Schachtwässer zu Trinkwasser mit Eisensalzen durch Flockungsfiltration wird beschrieben. Die Arseneliminierungsrate ist vor allem vom Konzentrationsverhältnis Eisen(III)/Arsen, dem pH‐Wert des Rohwassers und der Enteisenungswirkung der Kiesfilteranlage abhängig.Bei einem Arsengehalt des Schachtwassers von 0,30… 0,35 mg/l waren im Durchschnitt 1,8 mg/l Eisen(III) und ein Chlorüberschuß von ca. 0,5 mg/l ausreichend, um im Reinwasser den Grenzwert, As <0,05 mg/l, zu garantieren.Ergänzend werden erste Betriebserfahrungen bei der Aufbereitung arsenhaltiger Wässer diskutiert.
The Uptake of 226Ra by Planktonic Algae under Conditions of Continuous Cultivation
Authors: Havlík B. , Hanušová J. 
Published: February 2007

AbstractThe radium cumulation in Coelastrum cambricum, Scenedesmus obliquus and Microcystis pulverea was studied under conditions of continuous cultivation at constant level of radium in the cultivation medium. The algae were exposed to the concentrations of 30, 300 and 3000 Bq/l 226Ra in the medium for a period of 14 days. It was found that radium started to cumulate immediately after its addition to the culture just as in the stationary type of cultivation, in the continuous cultivation, however, its content decreased with the length of exposure. This is due to the decreasing part of radium adsorbed on the cell surface. While in green algae the portion of radium incorporated into cells increased with the length of exposure, in blue‐green algae up to 90% of radium was bound to the surface or gelatinous capsules of the cells through out the experiment. With the three phytoplankton species used, the highest cumulation of radium (nonwashable part) was recorded in Coelastrum cambricum. A dependence of the radium cumulation on its content in the medium was observed in the species Scenedesmus obliquus.
Acute Toxicity of Mercury, Copper and Zinc to a Freshwater Pulmonate Snail, Lymnaea luteola (LAMARCK)
Authors: Mathur S. , Khangarot B. S. , Durve V. R. 
Published: February 2007

AbstractThe short‐term toxicity of mercury, copper and zinc was studied using a freshwater pulmonate snail, Lymnaea luteola (LAMARCK). The median period of survival increases with decreasing the toxicant concentration. The 96 h LC50 values and their confidence limits were 0.135 (0.112 … 0.186) ppm of Hg2+; 0.172 (0.118 … 0.355) ppm of Cu2+; and 6.13 (5.73 to 7.19) ppm of Zn2+. The relative potency ratio indicates that the Hg2+ ions were most toxic, followed by Cu2+ and Zn2+ ions.
Beurteilung der Hydrolyseaktivität von Belebtschlamm mittels spezifischer chromogener Substrate
Authors: Vaňková S. , Kasafírek E. , Kupec J. , Mládek M. 
Published: February 2007

AbstractZur Bestimmung der hydrolytischen Aktivität einer heterogenen Kultur (Belebtschlamm) wurde die Eignung einer Reihe chromogener Substrate untersucht. Auf Grund der durchgeführten Untersuchungen wurden einige Gruppen von Enzymen bestimmt, die in dieser bakteriellen Population vorkommen. Synthetische chromogene Substrate erwiesen sich als geeignetes Mittel zur raschen und unter Laboratoriumsbedingungen einfachen Beurteilung der Kapazität eines Belebtschlammes, hochmolekulare Substrate zu zersetzen.
Chromium(III) and Chromium(VI) Circulation in Aquatic Biocenoses
Authors: Starý J. , Havlík B. , Zeman A. , Kratzer K. , Prášilová J. , Hanušová J. 
Published: February 2007

AbstractThe cumulation of chromium(III) and (VI) has been studied in batch cultures of planktonic algae Microcystis incerta, Scedenesmus obliquus, Chlorella kessleri and Chlamydomonas geitleri at different chromium and algal cells concentrations. It has been found that chromium(VI) is practically not cumulated in algae, whereas chromium(III) is very rapidly cumulated in all types of algae investigated. The cumulation factor increases with the decrease of the radius of algae cells and it reaches the value of 106 for Microcystis incerta even after a few hours of contact. The kinetics, the cumulation factors and the capacity of algae to cumulate chromium(III) is practically the same for living as well as for dead cells and therefore it can be concluded that the cumulation of chromium(III) is due predominantly to the chemical sorption on the surface of algal cells.
Cumulation of Zinc, Cadmium and Mercury on the Alga Scenedesmus obliquus
Authors: Starý J. , Havlík B. , Kratzer K. , Prášilová J. , Hanušová J. 
Published: February 2007

AbstractIn batch experiments with the metals labelled with their radionuclides the cumulation of zinc, cadmium and mercury on Scenedesmus obliquus in dependence on the pH‐value is measured, because the original pH‐value of the solution is changed by the algae due to their absorption of hydrogen‐ions. For the uptake of zinc and cadmium the logarithm of the cumulation factor in the range of 2 … 5 is a linear function of the pH‐value in the range of 5 … 9, cumulation increasing with rising pH‐value. In contrast, the mercury cumulation is pH‐independent. If the changed pH‐value is taken into account, the cumulation factors are independent of the metal concentration in the range = 10−4 mol/l. The degree of cumulation is not changed by the presence of other metals. The cumulation factor is reduced by substances forming negatively charged complexes with the metals.
Die Auswirkung von Tensiden und das Verhalten von Bakterien gegen‐über grenzflächenaktiven Verbindungen
Authors: Walther H.‐J. 
Published: February 2007

AbstractAn investigation was made into the effects of seven anion‐active tensides and one non‐ionic tenside on the growth and respiration of 19 strains of the bacteria genera Proteus, Pseudomonas, Aerobacter and Sarcina. A nutrient broth with phosphate buffer and partly glucose addition was used as the culture medium. Tenside was added either at the beginning of tests in the lag‐phase of cultures or during the logarithmic growth phase. In addition, the development of resistance or adaptation were tested by establishing subcultures. The inhibitory effect of tensides depends on the combination of tenside/species of bacteria, gram‐positive bacteria being more sensitive and the inhibitory effect being lower in their logarithmic growth phase. The time course of the inhibition of respiration after the addition of tenside to the medium shows different types of inhibition and adaptation, considerably extended lag‐phases occurring frequently.
A Contribution to the Mechanism of Elimination of Dimethylformamide and Dimethylamine by a Heterogenous Culture of Microorganisms
Authors: Houser J. , Hoffmann J. , Daťková H. , Konečný J. , Kupec J. , Mládek M. 
Published: February 2007

AbstractIn a batch experiment with activated sludge from a large‐scale plant the hydrolytical and biochemical degradation of dimethylformamide (DMF) and its reaction product dimethylamine (DMA) and the conversion connected with this under aerobic and anaerobic conditions is investigated. Parallel to the hydrolysis of DMF the biochemical degradation of DMA occurs. The extensive conversion of these substrates is followed by the nitrification of the ammoniumions formed, and under subsequent anaerobic conditions with methanol as the carbon source also denitrification can be achieved. If the oxygen supply of the activated sludge is insufficient, however, also DMA can be used as a carbon source for denitrification, ammonium‐ions being released from DMA in addition. In the batch experiment the elimination rates referred to nitrogen were 7 … 14 mg/g · h for DMF, 0.8 … 1.7 mg/g · h for DMA, 0.3 … 0.6 mg/g · h for NH and 0.4 to 1.3 mg/g · h for nitrate in the presence of methanol. DMF and DMA are obviously not suitable as the only carbon source for denitrification.
Oxidation and Accumulation of Benzo(a)pyrene in the Presence of the Baltic Algae
Authors: Irha N. , Kirso U. , Urbas E. , Kukk H. 
Published: February 2007

AbstractIn batch experiments with 0.5 nM benzo(a)pyrene in artificial sea water there are investigated the distribution and degradation of benzopyrene in the presence of various plants: Cladophora glomerata, Enteromorpha intestinalis, Fucus vesiculosus and Chara aspera (in each case 10 … 20 g/l dry weight). The conversion of benzopyrene in the presence of the plants is considerably promoted compared with the pure autoxidation, except in the presence of Fucus. Obviously, there prevails initially the accumulation of benzopyrene in the biomass. Whereas for Fucus even after 10 d still 89% of benzopyrene can be detected in the biomass, in the other species a degradation of benzopyrene in the biomass takes place, the respective oxidation products as diols, quinones and phenols being detected in the biomass in proportionately higher concentrations. With the exception of Fucus, the degradation of benzopyrene comes up to 40 … 60% within a period of 5 … 6d with the other species tested.
Zur Toxizität und Spurenanalyse von Tensiden in Wasser
Authors: Hanschmann G. , Sohr H. 
Published: February 2007

AbstractFor judging the behaviour of tensides in water there are required not only the results or the conventional methods of determining their biochemical degradability and toxicity, but also their distribution in the sediment as well as in animal and vegetable products. Very important are properties as adsorbability, persistence, sequence of stations in the nutrient chain (bioaccumulation), relations of structure and actions and dose‐effect relations. In these investigations also changed effects of combinations of substances with tensides have to be taken into account; a power plant water and Baltic Sea sediment being used as examples. From the variety of tested possibilities of analysing very small amounts of tensides mainly the infrared spectroscopy and the thin‐layer chromatography have proved to be successful. By means of special procedures, the detection and the quantitative determinability can be shifted into the nano‐ and picogram‐ranges.
Development of Heterotrophic and Ammonifying Bacterial Populations as Affected by the Fish Clarias batrachus (Linn.) under Different Experimental Conditions
Authors: Jana B. B. , Barat S. 
Published: February 2007

AbstractFishes of the carnivorous species Clarias batrachus of different size (length of 12 to 22 cm, weight of 15 … 57 g) were kept in aquaria with and without feeding on fish meal with or without an addition of rice bran, the fish mass having been 15 g/l. Aquaria with the same addition of food pellets were used as the control. The number of colonies of heterotrophic bacteria as well as the M.P.N. of the ammonifying bacteria was higher in the fish‐containing aquaria than in the control, and in the fish‐containing aquaria the colony number and the number of ammonifying bacteria significantly increased with the size of fishes and with feeding. The heterotrophic bacteria reached the highest numbers 4 h after the beginning, the numbers of ammonifyers increased till the fifth day. Parallel to the number of ammonifyers, also the ammonium concentration increased.
Wasserchemie und Stoffwirtschaft
Authors: Schubert M. , Kaeding J. 
Published: February 2007

AbstractFor the solving of the most important main tasks of water quality economy, of the supply of drinking water, industrial water and irrigation water without damaging or otherwise detrimental substances we need the available findings and results of specialized research in water chemistry. In the logical continuation of the further development up to the level of maturity for practice, the experts of the engineering disciplines have to be consulted. The design of the sequence of water treatment processes depends on the aims of the tasks set, there being increasing by raised the question concerning the possibilities of the saving and winning of energy and raw materials. — Already in the sphere of production, however, in the interest of environment protection one endeavours to achieve a direct or indirect low‐waste or non‐waste process design. Finally, possibilities of materials and power economy are discussed by the examples of the treatment of the wastewaters of the chemical industry and of municipal wastewaters.
Toxicity of the Herbicide 2.4‐D‐Na to Two Species of Freshwater Prawn of the Genus Macrobrachium
Authors: Omkar  , Shukla G. S. 
Published: February 2007

AbstractIn batch experiments with exposure for 24 to 96 h Macrobrachium naso and M. dayanum were exposed to solutions of the sodium salt of 2,4‐dichlorophenoxy acetic acid. The LC50,96h are 2.397 g/l for Macrobrachium naso and 2.275 g/l for M. dayanum. No mortality was observed in solutions of 2.1 and 1.85 g/l. The differences in toxicity are not dependent on the size of the organisms, but they are species‐specific.
Untersuchungen zum Einfluß limnischer Makrophyten auf die Absterbegeschwindigkeit von Escherichia coli im Wasser
Authors: Burger G. , Weise G. 
Published: February 2007

AbstractIn bioassays in aquaria, the dying of Escherichia coli was accelerated by Glyceria maxima, Schoenoplectus lacustris, Alisma plantago‐aquatica as well as Mentha aquatia as compared with check tanks without any plants (initial concentration 15 × 103 colony‐forming units per ml). As expected, by this the antibacterial effect of the limnic macrophytes attains its maximum effectivity within the first days of the period of investigation. The decimal time of reduction is shortened by one third to half, the centimal reduction time is shortened by one fourth to one third. Mean contact times of 7… 11 h are required for the decimation of bacteria by 90 %, and mean contact times of 16… 19 h are necessary for a 99 % reduction of the population. Possibly, the antibacterial effect in mixed stands of different plant species is increased additively or superadditively.
The State of Metal Ions in Natural Waters
Authors: Linnik P. N. , Nabivanets B. I. 
Published: February 2007

AbstractOn the basis of an analysis of literature and of own investigations, the state of metalions in natural waters is described as essential for the properties. There are investigated especially: hydrolysis, polymerization and complexation with humic substances. An analytical method for determining the degree of dispersion and the shares of free and complexed metal‐ions as well as their charge and molar mass is presented.
Relationship Between Organic Carbon and Chemical Oxygen Demad
Authors: Procházková L. , Blažka P. 
Published: February 2007

AbstractAn investigation is made on the COD/OC ratio for samples from two ponds, one brook, three rivers and four reservoirs, all samples having been taken from sampling stations with a low organic load, with 2.6… 127 mg/l COD and 0.9… 38 mg/l OC. The samples were filtrated by filtration with pore sizes of 40 or 1 μm. In the course of self‐purification, the OC concentration in rivers and reservoirs decreases to 8 mg/l, whereas ponds reached minimum values of the same size. The quotient COD/OC varies as the mean value for the individual waters between 2.55 in reservoirs and 3.92 in ponds. The overall trend of the values in the sequence of pond — river — reservoir is decreasing. The variability of the COD/OC ratios both within and between the groups results in artifinial intercepts in linear regressions of the two parameters. The distribution of the values is discussed, quotients larger than four may be associated with sulphur‐containing compounds possibly coming from the sediments.
Genesis of the Protective Layers upon the Mild Steel Surface in the Neutral Natural Waters
Authors: Bischof V. , Eliášek J. 
Published: February 2007

AbstractThe formation of protective layers against corrosion was investigated by experiments performed in three different media: drinking water, drinking water enriched by chlorides and a concentrated chloride solution. In explanations of the LANGELIER and RYZNAR indices it is stated that the results of both chemical‐physical relations supply only indications of the trends of solutions towards formation of protective layers or of aggressivity. The aggressive action of increasing chloride and sulphate concentrations is clearly inhibited by the presence of calcium(II)‐ and magnesium (II)‐ions. A high availability of alkaline earths and hydrogencarbonate allows the formation of a protective layer consisting of FeOOH · H2O, CaCO3 and FeCO3.
Nitrat im Trinkwasser — hygienische und aufbereitungstechnische Probleme
Authors: Putzien J. 
Published: February 2007

AbstractThe increasing nitrate concentrations in the ground water and drinking water which are caused by intensified fertilizing lead to the risk of methaemoglobinaemia of babies and increase the cancerogenic, teratogenic and mutagenic risk for the total population. In the drinking water conditioning the nitrate concentration can be reduced by different techniques. By ion exchange first the SO4‐ions and then the nitrate‐ions are removed. Very favourable is the exchange for HCO and the regeneration by means of carbon dioxide and CaCO3, for which a mass balance of substances is given. With 0.55 DM/m3 also the reverse osmosis in a mixture with raw water is practicable and also electrodialysis can be applied, whereas the biological techniques of the heterotrophic or autotrophic denitrification still include unsolved technological problems due to the necessity of an organic substrate or of H2. The special features of each of these techniques and the hygienic and also the corrosion‐chemical consequences are indicated.
Aldrin Induced Changes in the Activities of Three Phosphatases of Macrobrachium lamarrei (H. Milne EDWARDS)
Authors: Omkar  , Murti R. , Shukla G. S. 
Published: February 2007

AbstractMacrobrachium lamarrei is exposed to 0.008, 0.017 and 0.021 mg/1 aldrin (0.4, 0.8 and 1.0 of the LC50,96h) for 24… 96 h and after exposure the activities of the acid, alkaline and glucose‐6‐phosphatases are determined. With concentration and time of exposure the acid phosphatase shows an increasing activity up to 170 % compared with the control, which is interpreted as a part of prenecrotic changes in the cells. With concentration and time of exposure the alkaline phosphatase shows a decreasing activity down to 20 % of the control, which is indicative of considerable disturbances of the total metabolism. The glucose‐6‐phosphatase shows an increasing activity with the aldrin concentration up to 150 % during 72 h; then the activity drops to 60… 80 %. The initial rise in the glucose concentration of blood caused by that is the clear consequence of a stress reaction and the change of metabolism resulting from it.
The Influence of the Incubation Temperature on the Body Length and the Yolk Sac Volume of Coregonus albula (L.) Eleutheroembryos
Authors: Luczynski M. , Dlugosz M. , Szutkiewicz B. , Kirklewska A. 
Published: February 2007

AbstractEggs of Coregonus albula were incubated at temperatures of 1.1, 2.0, 4.9, 6.6, 8.4 and 9.9 °C. The successful hatching is optimum with 61 % at 4.9 °C; incubation time and period of hatching decrease significantly with rising temperature. The length of eleutheroembryos decreases with rising temperature, the yolk sac volume increases. Between the incubation time till hatching and the body length a significantly positive regression exists in the range of 4.9… 8.4 °C, for the yolk sac volume the regression is negative, it is significant in the range of 2.9… 6.6 °C; at the same time a negative regression exists between the yolk sac volume and the body length. Thus, low temperatures cause a delay of hatching, higher temperatures accelerate hatching and at the same time result in a reduced utilization of the yolk reserves. Besides these influences of temperature on the rate of ontogenetic processes, some autoecological consequences of the influence of temperature result, which have to be taken into account in further investigations.
Water Quality Control in Impoundments
Authors: Chalupa J. , Fiala L. , Popovský J. , Sládeček V. , Vašata P. 
Published: February 2007

AbstractThis report on a seminar of the Water Research Institute in Prague deals with the methodological aspects of the measurement and evaluation of data for the water quality in impoundments in the CSSR mainly with respect to: the assessment of external causes, especially of anthropogenic influences in the catchment area, on the water quality (eutrophication, humic substances, trace elements), of the multi‐purpose utilization of impoundments, the classification and development of the water quality in impoundments, the intensified utilization of impoundments as well as the influences of sediments and the effect of piscicultural measures on the water quality. The paper is subdivided into the following chapters: system of measurement network and analysis, stratification number of samples, number of the criteria to be investigated, extreme periods of discharge, multi‐purpose utilization of impoundments, eutrophication, fish stocks.