bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrogen, Phosphorus and Primary Production in the Pomeranian Bay
Authors: Kubiak J. 
Published: February 2007

AbstractThe Pomeranian Bay in the south‐western part of the Baltic sea has an area of 4300 km2 and a volume of 51.4 km3 and contains a fresh‐water inflow of 17.3 km3/a from a catchment area of 137,220 km2. There were evaluated 18 investigations of specific dates at 14 stations in the years 1976 … 1978: 229 … 235 hydrochemical measurements and 75 phytoplankton investigations. It can be demonstrated by multiple regression analyses that the nutrient concentrations are mainly determined by the fresh‐water inflow and the mixing ratios, phytoplankton having a secondary effect. Of the nutrients mainly ammonium influences the phytoplankton development and the oxygen production, the full utilization of the nitrogen stock being limited by an N/P ratio of 48 in the surface water and of 41 in the bottom water layers. Obviously, a limitation of the primary production is out of the question due to the high turnover rates of phosphorus. The N/P ratio is also a clear evidence of the great influence of the inflowing nitrate‐rich freshwater on the nutrient situation of the bay.
Molekular Connectivity Indizes als strukturchemische Stoffparameter ökotoxikologischer Relevanz
Authors: Koch R. 
Published: February 2007

AbstractThe molecular connectivity index developed by Randic as a numerical expression characterizes the position and bond of atoms in the molecular structure. Since significant correlations between the molar refraction as well as electron polarizability and ecotoxicologically relevant parameters of substances were determined in the preceding investigations, such connections are investigated also for this index and sorption coefficients, bioconcentration factors and toxicity data. By the example of 56 differentiated organic substances, significant regression relations are demonstrated between bioconcentration factors, sorption coefficients and toxicity data as well as the valency molecular connectivity indices. By these regressions it is possible to determine essential distribution and action parameters of chemical substances from the structure for assesing an ecotoxicological risk. The possibilities resulting from this for predicting ecotoxicologically relevant parameters of substances are discussed.
An Estimation of the Mercury Content in the Waters of the Pomeranian Baltic‐Shore‐Area
Authors: Wrembel H. Z. 
Published: February 2007

AbstractIn the catchment area of the Pomeranian Bay an average mercury concentration of 178 ng/l in precipitation was determined. Eight different flowing waters showed mean concentrations between 105 ng/l (Łupawa) and 500 ng/l (Odra), a pronounced annual cycle having been demonstrated for the concentrations and for the freights with the minimum in February/March and the maximum in August/September. The total freight of the eight rivers amounts to 19.5 t/a, the share of the Wisla being 11 t/a. The ratio between the mercury precipitation of 335 to 410 μg/m2a Hg and the run‐off varies of 30 … 75 μg/m2a Hg for the individual river basins between 0.08 and 0.21. In the Baltic Sea, the mercury concentrations are 40 ng/l in the open sea, 50 ng/l in the coastal region and 290 … 390 ng/l near the estuaries. Trough the eight investigated rivers about 48 km3/a water run off into the Baltic Sea with about 20 t/a Hg. The total introduction of Hg into the Baltic Sea is estimated at 100 t/a with the river water, 35 t/a with precipitation and 35 t/a with dust.
Zum Sauerstoffhaushalt der Gewässer der Feldberger Seenplatte an Hand ausgewählter sommerlicher Tiefenprofile seit 1924 und 1962 Teil 3: Scharteisen, Wasch‐See, Dolgener See
Authors: Richter W. M. 
Published: February 2007

AbstractThis paper presents the depth profiles of 1951 … 1980 for the Scharteisen, the investigations of the last years for the Wasch lake and the Dolgen lake, for the oxygen regime with the representation of the oxygen concentration, transparency, water temperature and the upper limit of the occurrence of hydrogen sulphide. The profiles demonstrate the eutrophication having occurred for the Scharteisen and the present state for the three lakes. The general situation of the drainage areas and the causes to be derived from it concerning changes of the water quality as well as possible measures and aims of sanitations are discussed. Also the most important data are given on the hydrography of these waters and on their utilization for obtaining drinking water and by fishery up to now.
Phenol Accumulation in the Larvae of the Species Agrion puella L.(Insecta, Odonata) under Laboratory Conditions
Authors: Erben R. 
Published: February 2007

AbstractIn an aerated batch experiment for one to six days the phenol accumulation is investigated in the surviving and killed larvae of Agrion puella at phenol concentrations of 50 to 200 mg/l in the medium. The rate of mortality increases with the initial concentration of phenol, although about 40% phenol is microbially digested during the test. The phenol accumulation in μg/g wet substance is always higher in the surviving individuals than in the killed ones, but it shows an identical time trend for both. On the first day, accumulation is high, and till the third day it decreases. On the fourth day, it reaches a maximum, and then it drops sharply to its minimum on the sixth day. The measured actual accumulation is the result of changing intake and elimination rates, especially the elimination rates decreasing with increasing duration of tests and test concentration due to metabolic disturbances. The absolute minimum on the sixth day is determined also by the reduced phenol concentration. The limit of accumulation for a chronic poisoning can be estimated at 70 μg/g phenol.
Elimination of Nutrients in the Rozkoš‐Reservoir
Authors: Maixner J. , Sládeček V. 
Published: February 2007

AbstractThe reservoir, having a volume of 76 hm3, a surface area of 1001 ha and a maximum depth of 17 m, is divided by a dam into two parts. Half of the upper part with an area of 200 ha is densely covered by macrophytes (Elodea, Potamogeton). The three main tributaries with 2.6 m3/s on an average are highly polluted and show α‐mesosaprobic conditions. The reservoir is investigated between September and March in its longitudinal section at eight stations. The organic load and the total solids show a total decrease by 60% and 66%, respectively, and 70% of this selfpurification occurs in the upper, separated part of the reservoir. In the same way, also the total nitrogen is reduced, whereas the total phosphorus is reduced already in the upper part of the reservoir by 71%, then decreasing to 21% in the second part of the reservoir. With phosphorus, besides the biological elimination obviously also precipitation by the dissolved iron occurs, the concentration of which is reduced by 44 or 76%, resp. The bacteriological load of water improved by two to three orders of magnitude.
“Man and the Biosphere”‐Studies on Sikkim Himalayas. Part 1: Acute Toxicity of Copper and Zinc to Common Carp Cyprinus carpio (Linn.) in Soft Water
Authors: Khangarot B. S. , Sehgal A. , Bhasin M. K. 
Published: February 2007

AbstractIn the daily exchange of the medium with only 7.1 mg/l Ca2+ and 0.7 mg/l Mg2+ during the batch experiment the LC50,96h for Cyprinus carpio is 0.063 mg/l Cu2+ and 3.12 mg/l Zn2+ at water temperatures of 11 to 14°C. Significant differences in mortality as referred to the LC50,12h occur for copper only after 72 h of exposure and for zinc after 48 h of exposure. The values of LC50,96h are clearly lower for both metals in the investigations described than most data given in literature for different fish species.
Mathematische Modellierung der Komplexbildung von Metallen und ihre Nutzung bei der Interpretation physikochemischer Prozesse in natürlichen Wässern
Authors: Fischer R. , Reissig H. 
Published: February 2007

AbstractA mathematical model is presented for the calculation of the concentrations or activities of complex compounds in the thermodynamic equilibrium state. Ten central atoms and ten ligands which form 400 complexes at the most can be included in the model. Complex stability constants, total concentrations of the central atoms and ligands, temperature and pH‐value constitute input quantities. Activity and temperature dependence of the stability constants are covered by respective subprogrammes. The model is tested by the migration rate of iron(II) within a sand‐filled column with a cation‐exchange capacity of 1 mval/100 g solid matter: If there is an excess of sulphate, the iron(II)‐breakthrough will be considerably earlier, the same holding for the EDTA‐complex, whereas by means of EDTA the iron(II) bonded to the soil by ion exchange can be redissolved. In the batch experiment also the rate of oxidation of iron(II) is dependent on the degree of complexing. The model can be extended for dissolving, precipitation and redox processes.
Über das Vorkommen von R‐Plasmiden in Escherichia coli und koliformen Keimen aus Wasser und Abwasser Teil 2: Methoden der Isolierung von R+ — Bakterien aus Oberflächen — und Abwasser, des Transfers ihrer R‐Plasmide sowie die Bestimmung der Resistenzbilder
Authors: Heier H. , Tschäte H. 
Published: February 2007

AbstractAfter a detailed description of the methods of investigation for the isolation of R+‐bacteria from water and wastewater, the determination of their resistance pattern and the transfer of R‐plasmides from wild strains to E. Coli K 12 there follows the communication of the results of investigations of the inflows and outflows of municipal and rural clarification plants as well as of a special hospital for lung‐diseases and a urological clinic. It was also found that coliform germs with a threefold and fourfold resistance were dominant in wastewater and surface water and that there was a pronounced shift to strains with a multiple resistance in hospital sewage. Particularly high were the values of the quotient of the single resistance in coliform germs from the wastewater of a lung‐disease sanatorium and of germs with multiple resistance in the waste‐water from an urological clinic. As can be demonstrated, here the selective pressure of the different chemotherapeutic agents used for the therapy is effective.
“Man and Biosphere” — Studies on Sikkim Himalayas. Part 2: Acute Toxity of Mixed Copper‐Zinc Solutions on Common Carp,Cyprinus carpio(LINN.)
Authors: Khangarot B. S. , Sehgal A. , Bhasin M. K. 
Published: February 2007

AbstractIn batch experiments for 6 to 48 h, individuals ofCyprinus carpio(2 g individual weight) were exposed to mixed solutions of copper and zinc sulphate: pH = 6.3, temperature 15 °C, 6.8 mg/l O2, 7.1 mg/l Ca2+, 0.7 mg/l Mg2+. The LC50for the individual substances on exposures of 24 and 48 h amount to 9.04 and 7.28 mg/l, resp., of Zn and 0.11 and 0.095 mg/l, resp., of Cu. The sum of the biological activity of the two kinds of metal ions is assessed according to MARKING'S index: at low concentrations of the mixed solutions the two metals show an additive effect, at higher concentrations a synergistic effect occurs.
Chemical and Physical Characteristics of Some Wetland Waters of Kashmir
Authors: Kaul S. , Trisal C. L. 
Published: February 2007

AbstractAn investigation was made in five wetland areas in the valley of the river Jhelum north‐west of Srinagar. Only two of the regions have regular inlets and outlets, the others are only rain‐fed. The water temperature is closely connected with the air temperature, and in the shallow water it determines also the oxygen concentration. The chemical characteristics of the alkaline and hard waters show pronounced annual variations, which are determined by the autotrophic bioactivity especially for nutrients and carbon dioxide. Due to the increased pH‐values also biogenic decalcification with correspondingly reduced calcium(II)‐ion concentrations results in the water. In each of the wetlands seven to ten stations were investigated, which had been chosen according to the dominance conditions of vegetation. For the differentiations as to time and space of the water chemism the variance analysis shows significant differences, except for water temperature and alkalinity.
Zur Frage der Karpfenintensivbewirtschaftung von Seen und Eutrophierung
Authors: Barthelmes D. 
Published: February 2007

AbstractNormally, 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.
Simulation des Nitratabbaus im Grundwasser
Authors: Schwan M. , Kramer D. , Gericke C. 
Published: February 2007

AbstractTen reaction vessels containing 1 m3 were used as the experimental arrangement. They were filled with coarse sand or fine gravel and installed 60 cm below the floor. The pore volume (water saturation) was 227… 260 l. Anaerobic conditions were established by the addition of 6 g glucose at storage. The reactors were given tap water with 50 and 200 mg/l NO from KNO3 in such a way that a volumetric rate of flow of 0.2, 0.4 and 0.8 l/d was created. The volumetric rates of flow corresponded to the natural recharge of groundwater, the recharge of groundwater under the conditions of irrigation and the conditions of an intensive wastewater ground treatment. In the effluent from the reaction vessels the nitrate concentration was determined every month. It was stationary from the 7th to the 55th month after the beginning of the experiment. The experiments are evaluated by means of a model which takes into account the diffusion, convection and kinetics of the nitrate degradation according to Michaelis‐Menten. A simple method for solving homogeneous non‐linear differential equations of the second order is proposed. The experimental and model results show a good agreement and prove the very slow nitrate degradation in the groundwater with kM = 210 mg/l, vmax = 1.5 mg/l · d or k1 = 0.005 d−1.
Beitrag zur Wertstoffgewinnung aus Industrieabwässern mit Ionenaustauschern
Authors: Fischwasser K. , Kaeding J. 
Published: February 2007

AbstractA description is given of the fundamentals and experience gained in practice for the employment of ion‐exchange resins of the Wofatit type for water cycling in electroplating, the nickel recovery from electroplating wastes, the recovery of ZnCl2 in the vulcanized fibre production as well as the regeneration of phosphoric‐acid pickling solutions. Wofatit AD 41 is sufficiently chromate‐resistant, peroxo compounds have to be removed in any case prior to the anion exchange. In circulation systems, countercurrent cation exchangers are not absolutely necessary, in the case of high quality demands on the deionate they are suitable, however. For the nickel recovery with the aid of Wofatit CA 20 the double‐regeneration (elution and activation) is necessary. Special experience is still necessary concerning the enrichment especially of organic disturbing substances. For the phosphoric‐acid regeneration the size and surface of the pickling bath, the capacity of the regeneration plant and the specific increase of the iron concentration in the pickling bath have to be exactly coordinated with each other. In the economic evaluation, amortization periods of one to three years result for the metal recovery.
Möglichkeiten der Korrelation unterschiedlicher Wasseranalysenverfahren
Authors: Winkler F. , Düwert B. , Patecki H. 
Published: February 2007

AbstractInvestigated are the regressions and correlations between TOC, CSD‐Cr, COD‐Mn, BOD5 and CHCl3‐extract for model waters with the substances Präwozell W‐ON 100 and Emulgator 30 contained in them as the most important tensides as well as for the real clarification plant influents of a chemical works. As expected, for the model waters in all cases highly significant regressions exist between the results of the different investigation methods. For the real wastewater there can be demonstrated statistically secured connections with degrees of determination of 0.64… 0.78 only for the pairs TOC ‐ COD‐Cr, BOD5 ‐ COD‐Cr, COD‐Mn ‐ COD‐Cr and TOC ‐ COD‐Mn, due to the varying composition. The corresponding regression equations with their range of definition are given. They can contribute to render the acquisition of measured values more efficient and to control the wastewater treatment.
Probleme der spektrophotometrischen Chlorophyllbestimmung
Authors: Wasmund N. 
Published: February 2007

AbstractFor the determination of the contents of chlorophyll a and phaeopigment a in sediment samples the method according to LORENZEN with its principle and the error sources is discussed in detail. The acidification required for the determination of the phaeopigments should be carried out on a final concentration of 0.006 mol/l acid. As an extracting agent, such a quantity of acetone has to be added to the sediment sample that a final concentration of 90 % acetone will be obtained with the interstitial water being taken into account. By an extraction done twice 90 % of pigments are extracted. Methanol as an extracting agents is unsuitable for several reasons mentioned. Exposure to light at more than 1 W/m2 results in a high rate of chlorophyll degradation, the same effect being shown by increased temperatures. Between the trichromatic chlorophyll determination according to JEFFREY and HUMPHREY and the determination according to LORENZEN exists the linear relation chl. a (J. and H.)=chl. a (L.)+0.6. phaeo. a (L.). The procedure of the determination of chlorophyll a and phaeopigment a according to LORENZEN is described in a detailed representation.
Physiologie des Phenolabbaus bei Rhodococcus spec. P1. Teil 2: Untersuchungen zur Regulation des Phenolabbaus
Authors: Hensel J. , Straube G. 
Published: February 2007

AbstractThe phenol‐degrading system which can be induced in Rhodococcus spec. P 1 brings about the metabolization of phenol via the β‐ketoadipate path (ortho‐cleavage of catechol). For the more precise characterization of the degradation performance investigations were made into the influences of different carbon sources: glucose, galactose, ribose, arabinose, xylose, acetate, citricacid, mandelic acid, protocatechoic acid, glycerol, tryptophane, phenylalanine and the complex substrate of nutrient broth as well as succinate, catechol and benzoate. Only the three last‐named substances show an influence: succinate inhibits only the synthesis of phenol hydroxylase, catechol and benzoate inhibit the synthesis and activity of phenol hydroxylase. As a comparison of the results with literature shows, even at the same path of degradation there are different regulating mechanismus in the different microorganisms.
Stofftransformationen in äquatischen Systemen und ihre hygienische Bewertung
Authors: Krassovski G. N. , Korolew A. A. , Scholdakowa S. I. , Koch R. , Dobberkau H.‐J. 
Published: February 2007

AbstractChemical substances can be transformed under the influence of physical/chemical and/or biochemical active factors. By this, the ecotoxicological and hygienic‐toxicological properties and effects of the substances are changed also with respect to toxicity, late effects (carcinogenetic, mutagenic, teratogenetic ones) as well as the bio‐ and geo‐accumulation behaviour. Such transformations occur also during water treatment, and therefore also the properties and effects of the transformation products have to be taken into account for determining the limit values for pollutants in raw water for the production of drinking water. Since frequently we have incompletely known transformation products or mixtures of substances, a coefficient of hazard is suggested for the evaluation. It is the quotient of the threshold concentrations of the initial substance and of the transformation products for the different (organoleptic, toxic, carcinogenic, teratogenetic etc.) effects. For several organic substances it is demonstrated that the transformation products can be regarded less toxic compared with the initial substance. Strong oxidants, however, cause an increased danger in many cases.
A Study on the Effect of Temperature upon the Toxicity of Sodium Pentachlorophenate to the Freshwater Snail Viviparus bengalensis L.
Authors: Gupta P. K. , Durve V. S. 
Published: February 2007

AbstractThe toxicity of Na‐pentachlorophenate to Viviparus bengalensis is investigated by batch tests with daily exchange of medium in the temperature range between 19 °C (February), 27 °C (April), 32 °C (June) and 30 °C (August) at times of exposure between 12 and 96 h. In the range of higher concentrations, pronounced abnormalities in behaviour by secreting mucus and discharging eggs and embryos occur. The LC50 are lowest for all times of exposure at 27 °C, whereas the times of survival with a given concentration are highest at 30 °C. From the LC50, 96h, 27°C = 66 μg/l results a safe concentration of only 47 μg/l Na‐pentachlorophenate for Viviparus bengalensis.
Potentiometrische Fluoridbestimmung in Trinkwasser
Authors: Seifert K. , Klaue W. 
Published: February 2007

AbstractThe measurement is carried out after addition of perchloric acid up to a concentration of 0.45 M perchloric acid, and the results are compared with those obtained in 0.16 M sodium citrate as well as with a gas‐chromatographic determination, and they show a good agreement, The detection limit is 0.002 mg/l F−, the coefficient of variation is nearly 0.01 at 0.85 mg/l F−, independently of whether a direct measurement or a measurement with a standard addition is carried out. The measurement is disturbed by aluminium(III)‐ and Iron(III)‐ions.
Diurnal Thermal Stratification and Floc Rising in Clariflocculators of the Tropical Water Works
Authors: Belsare D. K. , Prasad D. Y. 
Published: February 2007

AbstractIn four tropical water works there are carried out investigations on the floc rising occurring during the day‐hours, and especially in the hot season, in the flocculators. This phenomenon is caused by the great heating of the raw water during the day‐hours, due to which between 10.00 a. m. and 10.00 p. m. a temperature difference up to 3.7 K between the influent and the effluent of the flocculators occurs during a retention period of 3.5… 5 h within the flocculators. Even temperature differences of only 1 K result in floc rising, reducing the filter run by four to seven hours. Oversaturation of the raw water with oxygen by the photosynthetic oxygen production constitutes an additional cause. As a measure against the rising and passing‐on of flocs we recommend the aeration of the water at the raw water intake point, to prevent a thermal stratification during the day‐hours and at the same time to remove the perhaps given oxygen oversaturation.