bluuebunny/crossref_metadata_2025 huggingface dataset:
Population Dynamics, Biomass and Biomass Production of Eudiaptomus gracilis (G. O. SARS) in Two Water Areas of Differing Trophic State of Lake Balaton (Hungary)
Authors: Ponyi J. E. , Zánkai N. P.
Published: February 2007

Population dynamics and production of Eudiaptomus gracilis (G. O. Sars) were investigated in two basins of differing water quality of Lake Balaton from February through December, 1977. One of the basins (Keszthely) is considered to be hypertrophic. the other (Tihany) moderately eutrophic. Plankton samples were collected at weekly intervals.

The fecundity was 9.61 ± 3.39 at Tihany, and 16.53 ± 3.60 at Keszthely. The difference between the two basins was significant (P<0.1%). At Tihany the average number of eggs per m3 was lower by 36% relative to Keszthety.

The number of nauplii differed only a little between the two basins with the exception of April, when at Tihany the amount of individuals was nearly two times as great as at Keszthely.

In the case of younger copepodites (Stages I … III) the difference in individual numbers between the two areas of water was marked from February to June, while in other periods it proved to be small. At Tihany, the number of young copepodites was greater by 8%, on the average, than at Keszthely. The amount of larger copepodites (IV … V) relative to the total number of younger individuals of the population was by 63% resp. 77% smaller at Tihany and Keszthely.

In the whole period of these studies the number of adults was less by 44% at Keszthely than at Tihany. Their amount relative to that of nauplii was smaller by 6% at Tihany and by 45% at Keszthely.

At Tihany, the population biomass was at a constant high level during winter and spring (40 to 50 mg/m3), in summer values being lower (15 … 35 mg/m3). In the Keszthely‐Basin biomass showed more extreme changes, reaching a peak as high as 40 … 43 mg/m3 in April and November, but hardly exceeding 6 mg during July–August.

During the period of investigation, total biomass in the Tihany‐Basin was 342 mg/m3, at Keszthely 204 mg/m3.

Net biomass production‐two methods for estimation having been used – was higher in the Tihany‐Basin (17.25 and 33.83 KJ/m2), while in the Keszthely‐Basin it was considerably lower (13.06 and 9.50 KJ/m2).
Zur Aufbereitung von Oberflächenwässern unter Einsatz von Kalkhydrat
Authors: Walther H.‐J.
Published: February 2007

Die zunehmende Aufbereitung stark belasteter Oberflächenwässer und Uferfiltrate durch Flockung mit Aluminium‐ oder Eisen(III)‐salzen ist für nicht wenige Länder mit einem erhöhten Import dieser Chemikalien verbunden. Unter bestimmten Bedingungen kann der Einsatz von Kalkhydrat den Bedarf an Metallsalzen vermindern oder nicht mehr erforderlich machen. Es wird ein Überblick des Standes der hydrochemischen Grundlagenforschung zur Aufbereitung stark belasteter Oberflächenwässer und Uferfiltrate unter Verwendung von Kalkhydrat gegeben.
Abwasserbehandlung und Stoffrecycling bei der Lederproduktion
Authors: Kaeding J. , Walther H.‐J. , Werner E.
Published: February 2007

Bei der hohen Inanspruchnahme des Wasserdargebotes ist es vielfach not‐wendig, zu wassersparenden Technologien einschließlich der Gewinnung von Werkstoffen überzugehen. Am Beispiel der Lederproduktion erfolgt die Erläuterung derartiger Möglichkeiten. Diese hochbelasteten und schwer zu behandelnden Abwässer sind nach einer sinnvollen Teilstrombehandlung unter gleichzeitiger Rückgewinnung der Haupteinsatzchemikalien Natriumsulfid und Chromsulfat wieder nutzbar. Bei der hohen Belastung von Abwasserteilströmen mit organischen Stoffen sollte außerdem eine Proteingewinnung angestrebt werden.
Zur Toxizität einfacher und komplexer Cyanide gegenüber Wasserorganismen
Authors: Tscheu‐Schlüter M.
Published: February 2007

The toxic effects of alkali cyanide, complex cyanide‐containing heavy metal salts—as of iron, cadmium, copper, nickel and mercury—were investigated according to standard methods with the aid of the test organisms Poecilia reticulata (guppy) as well as the green alga Ankistrodesmus falcatus (β‐ bis α‐mesosaprobic). Since various complex compounds can be photolytically decomposed, also discontinuous light‐dark phases were used. As discussed equilibrium calculations have shown, inter alia also the pH‐value is important in the fish organisms used with different reactions to ions and molecularly dissolved compounds. The results are summarized in tables and graphic representations, the substances investigated being classified into groups with “strong” and “high” toxic actions.
Influence of Temperature on the Toxicity of Phenol and its Chloro‐ and Nitro‐derivatives to the Fish Notopterus notopterus (PALLAS)
Authors: Gupta S. , Dalela R. C. , Saxena P. K.
Published: February 2007

There is determined the LC50 for 24 … 96 h of phenol, 2,4‐dinitrophenol and pentachlorophenol as sodium salt by static assay at water temperatures of 16, 23 and 36°C. In addition, the combinations of the three substances were tested in the same way. With decreasing temperature, the toxicity of the individual substances decreased by 6.5 … 22%, that of the mixtures by 10 … 87%; with rising temperature, the toxicity increased by 38 … 747% and 75 … 744%, respectively. The safety limits at 23°C lie between 0.3 μg/l for a synergistically acting mixture and 0.9 mg/l for an antagonistically acting one; for the individual substances this range is 3.5 μg/l to 0.5 mg/l.
Bioindikation zur Verminderung von Stickstoffdüngerverlusten und der Stickstoffbelastung von Gewässern
Authors: Wegener U.
Published: February 2007

Prerequisite to the nitrogen leaching from agricultural soils in spring is the ecologically optimum control of the first nitrogen fertilizer application. On the basis of investigations having been carried out for some years, a method for determining the optimum time of fertilization with the aid of phenological data is presented. The blossoming data of Anemone nemorosa proved to be a suitable sensitive indicator, their onset of blossoming is the optimum time for the first nitrogen application. In dependence on the height and variation of weather, in the subdued mountains this time is 90 … 116 d after the beginning of the year and corresponds to a temperaturetotal ≥ 5°C of 80 … 120°C or > 0°C: 160 … 230°C. Possibly, the leaf development of Alchemilla vulgaris or the first development of Poa pratensis are suitable as other bioindicators. The boundary conditions and disturbance variables of the bioindication are discussed. By the phenological date‐determination of the beginning of fertilization the nitrogen losses can be reduced by 10 … 20% and the nitrate leaching can be considerably reduced especially in drinking‐water protection areas.
The Concentrations of Cadmium, Lead and Copper in Filtrated Baltic Sea Water Samples Collected at Two Seasons in 1969
Authors: Gustavsson I.
Published: February 2007

Two research cruises on the Baltic Sea, in July and November of 1979, were made for investigating the Baltic Sea water for its contents of dissolved cadmium, lead and copper. Atomic absorption spectrophotometry and voltammetry were used as methods of investigation, the latter method having supplied slightly lower results. In the water layer of 0 … 50 m the cadmium concentrations were 0.03 … 0.05 μg/l and the lead concentrations were 0.1 … 0.2 μg/l, seasonal changes did not have any effect on them. The copper concentrations, on the other hand, were 0.4 … 1.2 μg/l in summer and 0.1 … 0.7 μg/l in autumn. Compared with ocean waters, the lead content is remarkably high. In anoxic deep waters of the Baltic Sea the concentrations of the three metals, especially that of cadmium, are very low (< 0.01 μg/l).
Biologisch‐chemisches Verfahren zur Prüfung des Abbau‐ und Eliminierungsverhaltens organischer Abwasserinhaltsstoffe
Authors: Peukert V.
Published: February 2007

After the checking for the toxic inhibition of degradation, the testing of the degradation behaviour at concentrations below the toxicological threshold value should be performed. For this, activated sludge with 1.5 … 2 g/l organic dry weight in special reaction vessels with a stirring and aeration equipment as well as electrochemical oxygen measurement is used. The possibly necessary adaptation is effected by a repeated change of the aqueous phase with the test substance as the single carbon source. Measurements are carried out in three vessels: control, experimental vessel and another experimental vessel for the makeup of volume at sampling. The increase of biomass and the consumption of substrate are determined from samples. Determinations of totals as COD and/or Corganic are recommended, since the determination of the pure substrate allows only statements on the persistence, but not on the full degradation. The technique, represented with the schematic diagram and examples of application, can be automated easily.
Zum Abbau von Formaldehyd durch adaptierte Bakterien
Authors: Behrens U. , Hannes J.
Published: February 2007

Municipal activated sludge was cultivated in a medium composed of formaldehyde, glucose and mineral salt. By passages with increasing formaldehyde content a bacterial culture was selected which remained active also at initial concentrations of 1 g/1 formaldehyde. With this culture, formaldehyde and glucose were oxidized simultaneously to formate and gluconate, which subsequently served simultaneously as substrate for the growth of bacteria. Glucose alone was also oxidized to gluconate, which then was used as substrate for growth. Formaldehyde alone was only oxidized. If the actual formaldehyde concentration was kept low, however, by fed‐batch cultivation, it was assimilated also through formate formation. The biochemical background and the importance of the findings for the purification of formaldehyde‐containing wastewaters are discussed.
Sedimentchemische Untersuchungen in Küstengewässern der Deutschen Demokratischen Republik Teil 17. Spezielle Untersuchungen zur Dynamik der Oberflächensedimente eines flachen Boddengewässers (Barther Bodden)
Authors: Nausch G. , Schlungbaum G.
Published: February 2007

Repeated samples from the top 5cm of sediment in a homogeneous network of 100 sampling stations in the Barth bodden (mean depth—1.8 m) are analysed for dry weight, organic matter (loss on ignition), grain size distribution, total phosphorus and iron which is soluble in hydrochloric acid. The distribution of mineral and mud sediments (organic matter > 5%) follows the bottom topography: trays, closed basins and channels show the respective muddy concentrations; spits, ground waves and windexposed uplifts from depressions are mostly mineralic. The water depth has only a subordinate effect on distribution. After unquiet meteorological and hydrographic situations mainly the fine‐grained material is redistributed. As comparative investigations over four years show, due to this the distribution pattern is not changed fundamentally, so that the distribution of mainly mineralic, muddy and intermediate transition ranges can be mapped, unless this would be done according to surveys under extreme hydrographic and meteorological conditions. The individual parameters of the sediment quality show significant correlations between each other.
Biomass and Mineral Composition of Aquatic Macrophytes in the Hygam Wetland, Kashmir with Reference to Substrate Nutrients
Authors: Kaul S.
Published: February 2007

The wetland of 56 ha is situated at a height of 1565 m in the valley of the Jehlum river. Among macrophytes prevail Typha, Phragmites, Scirpus and Sparganium, and they are investigated at eight stations in the annual cycle. The mineral composition of the aboveground and belowground biomass and of the sediment was determined. The mean total biomass shows considerable variations, but also a pronounced annual variation with the summer maximum of 1445 g/m2 above‐ground and 1550 g/m2 below‐ground. The mineral constituents show clearly decreasing concentrations during the season of vegetation as far as potassium, calcium, magnesium and nitrogen are concerned, the nutrient contents lying between 0.041 and 1.9% P or 0.57 and 1.65 % N. In a regression analysis the biomasses show significant multiple regressions to concentrations of chloride‐ions, nitrogen and partly TPP and oxygen in the water and sediment.
Molmasseverteilung der organischen Stoffe im Prager Trinkwasser
Authors: Lischke P. , Chudoba J.
Published: February 2007

The water supply of Prague is based upon three different water resources: artesian groundwater and infiltrate of the Jizera river, water of the Vltava and Zelivka rivers. The processing techniques are different; consequently for the purpose of increasing capacity one has to search for the suitable raw water quality as well as for the optimum treatment process. An essential parameter for this is the contents of organic substances whose molar mass distribution is investigated by gel chromatography with the aid of Sephadex G‐10, G‐25 and G‐50. With respect to the total load of organic matter the Jizera shows the lowest values, in the Vltava the C.O.D. values are the highest, in the Zelivka the organic carbon shows the highest values. 80% of the organic substances in water have molar masses below 700. By flocculation 60… 70% of the C.O.D.‐Cr can be eliminated, the optimum removal of the high‐molecular substances occurring at pH = 6 and with 50… 60 g/m3 aluminium sulphate.
Eliminierung und Rückgewinnung von Metallionen aus Abwässern — eine Übersicht
Authors: Kümmel R. , Winkler F. , Beck R.
Published: February 2007

The present state and the trends of the recovery of heavy metals from wastewaters are presented. The classical precipitation techniques are insatisfactory due to increases of solubility in the presence of impurity ions and/or complexing agents. At present, ion‐exchange processes constitute the most frequently used method of metal recycling with an effective enrichment of metal ions. For the effective separation of metals from solutions of a low concentration the electrolytic reduction demands large electrode surface areas. In cells with fixed‐bed or fluidized cathodes one can obtain specific electrode surface areas of some 103 m2/mm3. For the future, processes of extraction and especially membrane separation will gain in importance. In the past few years, a large number of highly selective metal extracting agents as well as the liquid membrane permeation with suitable carriers were developed. Combinations of membrane separation processes with chemical reactions may attain the same importance, as e.g. ultrafiltration in connection with the fixation of metal ions to watersoluble polymers. In the long run, especially techniques will prevail which will not only result in metal enrichment but also in the recovery of the raw material water.
Bestimmung von Sulfid in Wasser mit einer ionenselektiven Elektrode
Authors: Neidhardt H.‐J. , Steinleitner H.‐D.
Published: February 2007

For the direct potentiometric measurement by means of a sulphidselective solidstate membrane electrode (as the reference electrode a calomel electrode with a salt bridge filled with 1M KNO3‐solution) there were mixed 25 ml sample with 25 ml sulphide‐antioxidant buffer (0.2 M ascorbic acid in 2 M NaOH, Ag2S‐saturated). Calibration is done with thioacet‐amide in the same buffer. This measuring arrangement determines sulphide concentrations of 1.5.10−6… 10−3 M. If the buffer is added to the samples in the ratio of 1 +1 immediately during sampling, the sulphide content will be stabilized by this for at least 24 h. The measuring method and its calibration are compared with other methods of calibration with Na2S and the potentiometric titration, the iodometric titration and the photometric determination. The method having been developed proves to be very selective and requires a minimum expenditure of time.
Efficaciousness of Certain Chemicals to Control Dracunculiasis — A Field Trial
Authors: Mehta S. , Srivastava R. C.
Published: February 2007

To prevent infection with Dracunculus medinensis, a carrier host, the copepod Cyclops, has to be controlled. After preceding laboratory investigations a field trial with well water and different additions of chlorine and sodium permanganate is carried out. The exposure is performed at an ambient temperature of 25… 40 °C and in bright and dark samples (5… 11 h of sunshine/d) as well as in the well. The residual concentrations of the two chemicals are an exponential function of the time of exposure with half‐times between 6 and 23 h for chlorine and 11… 30 h for sodium permanganate. The depletion of the two oxidizing agents under light is faster than in darkness. Dosage should be done in such a way that the LC90,24h after 24 h of exposure will not be fallen below; in a specific case, this guarantees at the same time that the permissible concentrations for drinking water will not be reached 96 h after addition. For this, initial concentrations of 30 mg 1 Cl2 or 50 mg/l KMnOr are necessary. Under these conditions, the Cyclops population had died on the seventh day after the application of chemicals, but after seven weeks it reached the original density again. With one application of chloride or sodium permanganate a week Dracunculiasis can be completely controlled.
Chemical Signals in Fishes: Theory and Application
Authors: Pandey A. K.
Published: February 2007

In this paper, a comprehensive survey is presented of the state of knowledge of the occurrence, chemical structure elucidation and biological importance of pheromones in fishes: fright and alarm substances, male and female sexual pheromones, intrasexual stimulants, school formation, social structure and individual recognition, pheromones and fish migration. Especially treated are the problems connected with the chemoreception under changed environmental conditions as well as the possibilities of utilizing pheromones or substances with a similar effect in fishery.
Studies on Primary Productivity and some Hydrochemical Aspects of a Polluted Water‐body of the Himalayan Jhelum Valley
Authors: Khan M. A.
Published: February 2007

The lake without any outlet (11 ha, 55000 m3, zmax 2,25 m) has a weak thermal stratification with maximum surface temperatures of 32.5 °C. The annual variation of temperature and depth of visibility is unimodal, with the maxima or minima in August. Phytoplankton consists mainly of Cyanophyceae. The primary production determined by the light‐dark bottle technique (oxygen method) varies in the annual variation between 0.3… 0.5 g m−2 d−1 C (winter) and 3.4… 4.6 g m−2 d−1 C (summer); as the annual means of 1975 and 1976 there were found 1.9 and 2.4 g m−2 d−1 C, resp., gross production at a utilization of 0.42… 2.85% of the radiation energy. The chemism is a well‐buffered hydrogen‐carbonate water (pH 8.1… 9.0) with 74… 90 mg/1 Na and 20.5… 31.5 mg/1 K and with a good nutrient supply (20… 40 μg/1 PO4—P and 100… 240 μg/1 NO3—N) at the same time.
Model of a Bacterial Culture Utilizing a Toxic Substrate in Continuous Flow Conditions
Authors: Teodorova S. E. , Sivriev I. K.
Published: February 2007

A model is designed and discussed for the popular growth of a bacterial culture which grows by using a single toxic substrate. The model is based upon an enzymatic reaction with irreversible inhibition by the substrate. The stationary state of the system is represented and the range of its stability against the parameters of the model is defined.
Methode zur Bestimmung des Ammoniakstickstoffes in Gewässern
Authors: Hoffmann I. , Nagy B. , Schneider J.
Published: February 2007

For the spectrophotometrical determination of ammonia in surface water the reaction with hypochlorite and thymol in alkaline solution is used. Compared with other techniques, expenditure is low, the reagents are stable for a long period of time and the reaction is little dependent on external conditions. In 2 cm cuvettes there can be determined 0.05… 0.5 mg/l ammonia nitrogen. Comparative investigations carried out at nine sites in the area of the lake Balaton have revealed concentrations of 0.2… 0.7 mg/l ammonia nitrogen.
Ein Beitrag zur Anwendung der Regressionsanalyse im Zusammenhang mit der Schätzung der Primärproduktion im Großen Müggelsee (Berlin) für den Zeitraum 1979… 1982
Authors: Stellmacher R. , Nixdorf B.
Published: February 2007

The lake Müggelsee, which is important for the drinking water supply of Berlin, has been thoroughly investigated for some years with respect to its quality state and conversion of substances. To reduce working time and material expense for measuring of the primary production, with the aid of the results of series of investigations having been performed for years there are checked various mathematical‐statistical possibilities. Of the calculating methods studied the linear regression through the origin and the exponential approach provided the best approximation of measured and calculated results of the surface integral of the primary production as estimated from the production value of the optimum horizon for the type of the lake Müggelsee.
Zum Umweltverhalten von Fluortensiden. Teil 2. Untersuchung der biochemischen Abbaubarkeit
Authors: Prescher D. , Gross U. , Wotzka J. , Tscheu‐Schlüter M. , Starke W.
Published: February 2007

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.
Kurzzeitermittlung der Ablaufqualität von Belebtschlammanlagen anhand der Atmungsaktivität
Authors: Spörl R. , Milz J.
Published: February 2007

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.
On the Treatment of Industrial Wastewaters Carrying Oily Emulsions, Surfactans and Sulphates
Authors: Gomolka E. , Gomolka B.
Published: February 2007

The successful purification of waste waters from the leather and textile industries is possible by flocculation with aluminium sulphate and alkaline‐earth chlorides. BaCl2 proved very successful among the applied alkaline‐earth chlorides. The removal of oily emulsions and tensides was very effective when the waste waters were treated by a two‐stage flocculation process. By an excessive application of BaCl2 also a reduction of sulphate was obtained. Wastewaters treated in the neutral range showed a purification effect of 98 %, so that the effluents were clear and colourless. The time of sedimentation amounted to 1 h only. Segregated oil was successfully removed with the aid of a very absorptive polyurethane foam.
Hydrobiological Investigations of the Water Quality of the Water Supply Reservoirs Husinec and Římov
Authors: Porcalová P.
Published: February 2007

The two eutrophicated reservoirs Husinec (2.6 km3, 35 ha, zmax 18 m, MQ 1.87 m3/s) and Římov (34.5 hm3, 216 ha, zmax 44 m, MQ 4.14 m3/s) show concentrations of total phosphorus of 10… 50 mg/m3 and chlorophyll contents of 7… 36 mg/m3 in the summer season. For both reservoirs a good correlation exists between the chlorophyll concentration and the density of the phytoplankton (20 · 103… 13 · 106 ind./l). With average concentrations of 10… 20 mg/m3 chlorophyll a in summer, the water can be treated for producing drinking water only at a higher expenditure. The water quality will be improved by a reduction of the phosphorus load.
Zur Beurteilung der Produktivität von Suspensionskulturen einzelliger Grünalgen bei definierten Lichtverhältnissen
Authors: Seiss U. , Borns E. , Böhm H.
Published: February 2007

A description is given of the possibility of a comparison of the production between different suspension cultures of microalgae at equal and defined light conditions. For this, a variant of the turbidostat technique is used by which with the acid of a phototransistor and the filter combination of red filter/opal glass filter a chlorophyll‐equivalent signal is applied for control. The equal light conditions are compared and set by the preparation of the respective absorption profiles. From this one can derive the mean level of irradiation within the suspension cultures and use it as the reference value for the light conditions. By this technique it is possible to set equal light conditions in suspension cultures independent of the given cell sizes, cell shapes and dry matter contents.
Untersuchungen zum Vorkommen von R+‐Bakterien im Flußwasser
Authors: Stelzer W. , Ziegert E.
Published: February 2007

With colony numbers of 2 · 104… 3 · 105 and coliform contents of 2 · 103… 1 · 1 · 104 per ml, in the investigated river section 2.1% of colonies were resistant to tetracycline, 0.3% to chloramphenicol, 7.5% to kanamycin, 5.4% to trimethoprim, 12.7% to ampicillin and 0.14% to gentamycin. For the coliforms the resistances were 5.1% to tetracycline, 2.1% to chloramphenicol, 2.7% to kanamycin and 0.15% to gentamycin. There were isolated 63 different resistance types. Of the resistant Klebsiella strains 75% were resistant to three or more antibiotics. Of the coliform bacteria (Escherichia coli, Klebsiella, Enterobacter, Citrobacter) 31.6… 51.9% of the strains transferred their antibiotics‐resistance to Escherichia coli K‐12, for the antibiotics‐resistant strains of Pseudomonas and Aeromonas a transfer of resistance was not observed at all.
Phycoperiphyton Development on an Artificial Substrate in the River Wye System, Wales, U. K. Part 1: Biomass Variation
Authors: Antoine S. E. , Benson‐Evans K.
Published: February 2007

The phycoperiphyton on Perspex slides is investigated after an exposure for four weeks at six stations in the upper course of the River Wye System from June 1979 to June 1981. The pigment contents were between 0.1 and 48 mg/m2 chlotophyll‐a as well as 0.01 and 18 mg/m2 phaeophytin with a unimodal or bimodal annual variation (minima in winter, maxima in April and July). The biomass was between 55 and 11,000 cells/cm2 and is closely correlated with chlorophyll in the annual variation. The algal community colonizing the artificial substrate shows only a very slight similarity to that on the natural stones of the water. The SØRENSEN index lies between 0.1 and 0.7, the biomass on the artificial substrate amounts to only 0.7… 0.01 ‰, the chlorophyll quantity only 0.5… 0.007‰, the phaeophytin quantity only 1… 0.003‰ of the values on the natural stones. Therefore, the periphyton on artificial substrates represents only a more or less restricted selection of the real natural phycoperiphyton. At four of the six stations, biomass and chlorophyll are positively correlated with each other and with temperature and phosphorus concentration and negatively correlated with flow, current velocity, oxygen concentration, hardness and nitrate concentration.
Physico‐chemical Limnology of Lake Naini Tal, Kumaun, Himalaya (U. P.), India
Authors: Pant M. C. , Sharma P. C. , Sharma A. P.
Published: February 2007

The monomictic lake at a height of 1937 m, having an area of 48 ha, a mean depth of 16 m and a maximum depth of 27 m, is subjected to such an intensive use in its drainage area that the lake became eutrophicated. The spatial‐temporal distribution of important physico‐chemical criteria is represented for a period of two years. The depth of visibility varies between 0.4 m (March) and 2 m (June). The thermal stratification keeps up from March to November; therefore in the deep water zone a typical oxygen depletion and an enrichment of PO4P (26 μg/l) and of Ninerg (940 μg/l) occur. The pH‐value lies in the alkaline range and shows a significantly positive correlation with primary production and temperature and a negative correlation with the carbonate content. Also the oxygen concentration is positively correlated with the primary production and temperature. During stagnation, the sediment/water contact zone is free of oxygen for ca. 70 % of the area.
Einsatzkriterien, Untersuchungsmethoden und Qualitätsanforderungen für Aktivkohlen zur Trinkwasseraufbereitung
Authors: Huhn W.
Published: February 2007

The present state of the above mentioned points, inclusive of the determination of the degree of exhaustion and of the effect of regeneration is described and the respective methods of investigation are briefly explained. The statements made in this article constitute the contents of two drafts of respective special‐field standards concerning “water purification carbon”.
Identifizierung ausgewählter Pestizide im Wasser mit Hilfe eines screening‐Systems auf Grundlage der Dünnschichtchromatographie
Authors: Lienig D. , Schäfer K. , Reichelt G.
Published: February 2007

After their extraction from water, 16 water pollutants of the families of triazines, urea herbicides, phenoxycarboxylic acids and organochlorine and organophosphorus insecticides are separated and identified by thin‐layer chromatography. The method is suitable for routine analyses and was tested on model waters, inclusive of water from the Elbe river. The rate of redetection is up to 80%, the detection limit is at 0.5… 2 μg of the individual pollutants.
Zur Bemessung unterirdischer Enteisenungsanlagen. Teil 2: Kinetik der initialen Sauerstoffzehrung im Bodenmaterial eines reduzierten Grundwasserleiters
Authors: Reissig H. , Cnauck A. , Schwan M.
Published: February 2007

The experimental investigations were carried out on drill‐core samples in dynamical filtration tests with air‐saturated and oxygen‐gassed water. The description of the oxygen depletion, to which reactions with different rates contribute, is possible with regression equations as well as with balance equations. The first ones are suitable mainly for short‐time predictions, while the latter ones, for long‐term predictions. For a transfer to underground plants the temperature dependence of the rate of reaction should be taken into account.
Schadstoffbeseitigung aus Wasser durch Aktivkohleadsorption und Membranfiltration
Authors: Reissaus K. , Starke W.
Published: February 2007

The adsorbability of substances contained in water on activated carbon can be assessed relatively well from the physical and chemical properties and specific structural features of the substances. For difficultly adsorbable substances there have to be used combined techniques as coagulation/use of activated carbon, ozonation/use of activated carbon, membrane filtration/use of activated carbon or bioadsorption in the treatment of water. The two last‐named techniques are outlined. Especially the bioadsorption as a combination of physical adsorption and biochemical oxidation inside the carbon filter constitutes a valuable technique of water treatment for some substances and combinations of substances.
Deleterious Effects of Arsenic on the Nucleic Acids and Protein Metabolism in the Liver of Heteropneustes fossilis (BL.) — a Freshwater Teleost
Authors: Shukla J. Pd. , Dwivedi U. N. , Tewari P. , Prasad M.
Published: February 2007

The present paper deals with the toxic effects if any of the two concentrations of Arsenic(III)‐oxide on the nucleic acids and protein metabolism in the liver of H. fossilis after exposure for 20 and 30 days. Causes for significant alterations have been discussed.
Occurrence and Chemistry of Zinc in Freshwaters — its Toxicity and Bioaccumulation with Respect to Algae: A Review. Part 1: Occurrence and Chemistry of Zinc in Freshwaters
Authors: Vymazal J.
Published: February 2007

Zinc is a fairly abundant metal, it has been estimated that zinc represents 0.004 percent of the earth's crust and is twenty‐fifth in the order of abundance. Its concentrations in surface waters vary greatly with locality; the highest concentrations of zinc have been observed in areas with acid mine drainage, but zinc enters surface waters in many other ways. Chemical thermodynamic calculations summarized by solubility graphs are given. The zinc solubility may be significantly controlled by stream sediments; Zn concentrations of sediments from various areas are given. Many techniques for extraction from sediments have been developed, they differ in efficiency.
Migration of Lead‐210 and Stable Load in Surface Waters Impacted by Uranium Mine Wastes
Authors: Beneš P. , Zvclánek L. , Čeochanová M.
Published: February 2007

Water and sediment samples from two surface water systems were analysed for 210Pb and stable lead in order to elucidate the environmental importance and fate of 210Pb released from uranium mining. In one system mine drainage waters treated by precipitation of barium sulfate contained a considerable activity of 210Pb in particulate form. Spoil piles were the main source of 210Pb in the second system, with the dissolved 210Pb being the predominant migration form. In both systems the concentration of 210Pb rapidly decreased with distance from the source indicating that waterborne 210Pb did not represent an environmental problem. Uranium mining did not add significant amounts of stable lead into the surface water systems. It has been found that bottom sediments are a sensitive indicator of the pollution of surface waters with 210Pb.
Beiträge zur Dynamik der Biomasse in Oxydationsteichen. Teil 3: Untersuchungen an der Teichanlage Greifswald‐Ladebow nach Einsatz einer Kreiselbelüftungsanlage
Authors: Schwarz S.
Published: February 2007

The wastewater treatment is carried out in two parallel pond groups: South–9200 m3/d, 1748 kg/d BOD5, preliminary clarifier (1.1 ha, 22000 m3), three ponds (9.8 ha, 88000 m3), naturel aeration; North −5700 m3/d, 2394 kg/d BOD5, Imhoff tank, three ponds (7.9 ha, 71000 m3), the pond 1 artificially aerated by gyroscopic units. The different loads of 15.9 and 33.7 g/m3 d BOD5 results in rates of removal of 11.2 and 22.5 g/m3d BOD5, resp. Therefore, the efficiency of the naturally aerated system is higher than that of the artificially aerated system. In the aerated system mainly the bacterial growth is promoted, a typical algal state being achieved only slowly, whereas the naturally aerated system gains a summer‐time algal maximum in the ponds 2 and 3, which is accompanied already by zooplankton populations. In the dynamics of the biomass development, the higher efficiency of the four‐stage, naturally aerated system is especially obvious.
Eine rationelle Variante der ΔpH‐Methode zur Bestimmung von Cholinesterasehemmern in Wasserproben
Authors: Schmaland G. , Schulert H.
Published: February 2007

Water samples of 100 ml are salted out with 35 g NaCl and extracted with 3 × 10 ml chloroform, the extract is dried and taken up with 0.2 ml ethanol. The ethanol extract is incubated with 7.857 mmol/l acetylcholinhydrochloride and an enzymatic activity of 88.8 U/l cholinesterase from horse‐serum. An inhibition of cholinesterase and, therefore, of the formation of acetic acid from acetylcholin is caused by P‐organic insecticides present in the investigated extract. Since the reaction proceeds in a buffer at pH 8.2 … 8.3, the pH‐difference occurring between sample and control constitutes a measure of the cholinesterase inhibition. Prior to reaction, an oxidation is required for thio‐compounds, which is carried out with bromine water for parathion and with potassium permanganate for dimethoat. The detection limits of the method are in the nanogram‐range. Extractives from plants as well as substances from faecal matter may have a disturbing effect.
The Accumulation of Crimidin in Some Fish Organs
Authors: Janalík B. , Wohlgemuth E.
Published: February 2007

The accumulation of crimidin in total samples and in some organs of five fish species was studied under experimental conditions. The species were Cyprinus carpio, Carassius carassius, Tinca tinca, Scardinus erythrophthalmus and Leucaspius delineatus. Fish were exposed to concentrations of 10 mg · l−l and 50 mg · l−1. During short‐term experiments water and fish samples were taken at intervals of t = 0, 6, 12, 24, 48 and 72 hours, during the long‐term experiment sampling was performed weekly for six weeks. Total samples were analysed for C. carassius, T. tinca, S. erythrophthalmus and L. delineatus.

Samples of individual organs and tissues were taken as follows: C. carpio – gills, digestive tract, muscular tissue, kidneys, gonads; C. carassius – gills, digestive tract, muscular tissue, ovaries, testes. Crimidin was determined by gas chromatography. In samples from the short‐term experiments at a concentration of 10 mg · l−1 in the water the amount was roughly 101–10 mg · kg−1, at a concentration of 50 mg · l−1 in the water roughly 101 mg · kg−1. In most cases the accumulation coefficient was lower than 1.0. The accumulation capacity of individual fish species did not differ greatly. Of the internal organs only the kidneys had a high accumulation capacity, otherwise the highest values were found in muscular tissue and the gills. After one – three weeks the amount of crimidin in most organs falls, and after transfer to clean water there is a general sharp decline. Thus crimidin is not firmly bound in the body.
Analyse der Wasserpflanzenentwicklung in Grabensystemen zur Grundwasserregulierung
Authors: Küchler L.
Published: February 2007

The meliorated Oberes Rhinluch fen is used by agriculture as grassland with maize‐cultivation on about 30 % of its area. In the ditch system of this area with water levels of 30 to 150 there were observed 67 taxa of aquatic plants and marsh plants, of which about 15 achieve covering degrees of more than 3 % and form 80 … 90 % of the biomass. Biomasses of between 20 … 184 g/m2 dry weight (Lemna) and 504 … 1612 g/m2 (Phragmites) are obtained in pure populations. In mixed populations the biomasses amount to between 304 and 916 g/m2 dry weight. According to their density and orientation, riparian copses and trees cause a more or less intense overshadowing of ditches, resulting in a considerable reduction of the biomass of macrophytes. By copses and trees on the south side of the waters the light available may be reduced to 30 %, from which a reduction of the biomass to 10 … 30 % results. By means of such planting it is possible to control the growth of plants in order to reduce the necessary and very expensive weed‐removal and bottom‐clearing actions.
Zur Bemessung unterirdischer Enteisenungsanlagen Teil 1: Chemisch‐analytische Methoden der Erkundung und Bemessung
Authors: Reissig H. , Eichhorn D.
Published: February 2007

In underground deferrization processes there exists a dynamic cation exchange euquilibrium for Fe‐II to the solid phase of the underground when an Fe‐II containing ground water is delivered. Methods of investigation for the estimation of the initial oxygen demand and of the Fe‐II content of the aquifer are tested and described in detail. At dynamic filtering tests and within the framework of technically simpler batch‐tests the oxygen demand was higher than expected according to the stoichiometric Fe‐II share. A relatively good agreement was obtained between the results of both procedures. Fe‐II bound to solid matter is measured by a developed Fe‐III difference method. Fe‐II can be extracted and determined also directly with 1,10‐phenanthroline. Moreover, the determination method of the distribution coefficient with its influencing factors is described. Finally, the results of regression relations are explained.
Neue ingenieurbiologische Bauweisen unter besonderer Berücksichtigung des Einsatzes von Röhricht‐ und Unterwasserpflanzen
Authors: Heym W.‐D. , Weise G. , Jorga W.
Published: February 2007

The use of living plants for mechanical‐technical purposes (stabilization by plants) in the field of design and construction in the sense of biological engineering – a field of application of ecological engineering – concerns a complex system in which factors of soil mechanics and hydraulics are combined with the ecosystem. In comparison with solid‐technical construction methods, considerable advantages result due to a lower expenditure for maintenance and a high stability, especially during floods. Findings having been gained so far concerning the stabilization of the bank toe by underwater plants and flooding forms of species of reeds communities, the stabilization in the range of the mean water level and above it by bushes and shrubs – in cases of long‐time submerging by species of the reeds and swamps of large sedge (Phragmites) and of the wet meadows (Molinietalia) are critically evaluated, with the inclusion of new own findings from plantings in a newly developed section of the Branitz inland ditch (initial plantings in water and at the lower part of the bank) which have been observed for some years and from reed plantings covering large areas in the pond region of Peitz (Cottbus county, south‐eastern part of the GDR).
Einfluß der organischen Belastung auf die biozönotische Struktur des Makrozoobenthos in lithorheophilen, psammorheophilen und pelorheophilen Zönosen der Gebirgsbäche
Authors: Habdija I.
Published: February 2007

This paper deals with an investigation of the influence of organic load of different intensity (from oligosaprobic to polysaprobic level) on the biocenotical composition of macrobenthic fauna in lithorheophilous, psammorheophilous and pelorheophilous communities in small mountain streams. The stability of macrozoobenthos composition towards a successive increase of organic load in certain communities is established on the basis of biocenotical analysis and diversity index.
Untersuchungen zur Einzel‐ und Gemischadsorption von Phenolen an Aktivkohlen. Teil 2: Gemischadsorptionsgleichgewichte des Systems p‐Nitrophenol/p‐Chlorphenol/Aktivkohle
Authors: Worch E. , Zapke R.
Published: February 2007

On the thermodynamic basis of the theory of the Ideal Adsorbed Solution (IAS) a calculation method was used to predict mixture adsorption equilibria from the individual isotherms. The results of the prediction were compared with the results of practical measurements by the example of the adsorption of p‐nitro‐ and p‐chlorophenol mixture on the activated carbon DO 4. According to the explanations concerning the graphically represented results, the mean percent differences between calculated and experimental data by the exact solution of the IAS‐theory and by a described simplified method were 11 % and 13 %, respectively. It is thus confirmed that the IAS‐theory is very well suited for predicting adsorption equilibria for, e.g., phenol mixtures.
Effect of Activated Sludge Loading on the Floc Strength and Separation Characteristics of Fine Particles
Authors: Handová Z. , Sladká A.
Published: February 2007

Based on experimentally determined floc breakup rate coefficients and aggregation rate coefficients, the relations between floc coherence, physiological state of the mixed liquor, separation characteristics of not easily settling suspended particles and technological parameters were demonstrated.
Anreicherung von Metallionen durch Membranfiltration von Polyelektrolytkomplexen
Authors: Schumann G. , Kümmel R.
Published: February 2007

The separation of heavy metals by complexation with macromolecular water‐soluble agents and subsequent ultrafiltration is described. The method can be expected to join common techniques of metal separation like liquid‐liquid extraction, adsorption, redox reaction or liquid membrane permeation. Reactions between metal ions and polymer phases are characterized as pH‐dependent distribution equilibria illustrated at a propene‐maleic acid copolymer as an example. The complexation behaviour of the substance under study is governed by isotherms of the saturation type. Attempts proved to be successful to calculate break‐through constants as well as saturation capacities from batch‐type studies and dynamic measurements by transferring the laws of adsorption and ion exchange, respectively, to the ultrafiltration process. The quantities of fixed metals amounting to about 2.5 mmol/g were found to be in the range of moderate adsorbents. A solution consisting of 3 solutes has been tested to get more detailed information on mixture behaviour as compared to single component systems. In the long run, the proposed method should provide an additional variant for the extraction and concentration of metal ions from diluted aqueous solutions.
Untersuchungen zur Einzel‐ und Gemischadsorption von Phenolen an Aktivkohlen. Teil 3: Zur pH‐Abhängigkeit der Adsorptionsgleichgewichte
Authors: Worch E.
Published: February 2007

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.
Histopathological Changes Induced by Pentachlorophenol and Sodium Pentachlorophenate in the Mantle of the Freshwater Snail Viviparus bengalensis (L.)
Authors: Gupta P. K. , Durve V. S.
Published: February 2007

The freshwater pondsnail Viviparus bengalensis (LINNAEUS) was exposed to sublethal concentrations of pentachlorophenol (1.561 mg/l) and sodium pentachlorophenate (0.991 mg/l). Both the chemicals caused considerable damage in the mantle of the snail. Their toxic effects included shrinkage and elongation of epithelial cells, the cells losing contact with each other, resulting in the formation of intercellular spaces, enlargement of nuclei, shrinkage of the basement layer and loss of shape of polygonal cells of connective tissue.
Untersuchungen über den Harnstoffeintrag in das Badewasser
Authors: Gunkel K. , Jessen H.‐J.
Published: February 2007

As investigations carried out in an immersion basin of a sauna, with rinsed‐off sweat and in indoor and outdoor swimming‐baths have shown, from the total of 702 ± 529 mg/urea released per bather there are released 37.06 ± 24.75 mg through the skin into water; hence a urine introduction of 30 … 35 ml per bather resulting. The urea concentration in the bathing water does not show any correlation with the NH+4‐concentration and the COD‐Mn. Although urea‐degrading bacteria are present with concentrations of up to 1 ± 105 colonies/ml, there does not occur any enzymatic decomposition of urea in the bathing water. Nitrification was not detected in the bathing water, either. The use of urea as a hygienic quality criterion for bathing water is not regarded as necessary: the determination of the NH+4‐concentration suffices as an indicator of the pollution with faecal matter and the bound effective chlorine.