bluuebunny/crossref_metadata_2025_split huggingface dataset:
Beschaffenheitslängsschnitt eines Flußgebietes mittels Regressionsanalyse
Authors: Gnauck A. , Weber E. , Suhr U. 
Published: February 2007

AbstractFollowing a general representation of the regression analysis, especially concerning the relations between flow and concentrations of matter and loads, these relations are represented and discussed for the suspended solids, nitrate concentration, chloride content and oxygen concentration for seven sections of the Spree river. There result clear connections to the structure and utilizations of all of the parts of the river basin. Finally, the covering of the total river basin by models of water quality management in the form of regression, self‐purification and eutrophication models‐and their coupling is represented.
Studies of Aquatic Fungi. Part XXII. Mycoflora of the River Węgorapa and its Tributary, the River Goldapa‐Jarka
Authors: Czeczuga B. 
Published: February 2007

AbstractThe work was undertaken to investigate the mycoflora of the river Węgorapa and its tributary, the river Goldapa‐Jarka. Samples of water were collected in two years (1987‐1988) for hydrochemical analysis and studies of the content. Thirty‐seven species of fungi were found in these rivers. The following fungi, which had been unknown in Poland, were found in these rivers:Hapalopera fragilariae, Rhizophlyctis petersenii, Olpidiopsis vexans, Aphanomyces ovidestruensandPythium inflatum.
Statistical Analysis of Complex Round Robin Tests
Authors: Henrion R. , Henrion G. , Heininger P. , Steppuhn G. 
Published: February 2007

AbstractDifferent possibilities for the evaluation of complex round robin tests are presented. The advantages of 3‐way over classical principal components analysis when applied to 3‐way data arrays are discussed. The method allows extreme data reduction without essential loss of information. This is useful first of all for a graphically oriented evaluation of laboratories. The results of 4 round robin tests (8 laboratories, 5 parallel estimations, 4 trace element concentrations) for the analysis of heavy metals in waters (synthetic solutions with known concentrations) serve as an example. Special attention is paid to the recognition of different kinds of errors (random and systematic errors or unstable working).
Belastungscharakterisierung von Flußabschnitten der Saale und der Weißen Elster mittels Faktorenanalyse
Authors: Geiss S. , Einax J. 
Published: February 2007

AbstractLoads along a river can be characterized and differentiated with the aid of the factor analysis after suitable normalization. The factor analysis as a multivariate‐statistical evaluation allows the finding of sources of contamination, their objective assessment and quantification in relation to the conditions found in the river. The analysis of the river Saale shows a geogenic factor all the year round, which is composed of hardness elements, a seasonally fluctuating factor that can be represented in summer only, by which especially the processes of nitrogen conversion are recorded (nitrate, nitrite, organic load). An “industrial factor” contains the heavy metals Cu, Cr and Zn as well as temperature and sulphate, whereas cadmium, suspended matter and chloride result from municipal wastewaters.
Water Demands for Backwash in a Water Treatment Plant
Authors: Dąbrowski W. , Bielawka J. 
Published: February 2007

AbstractWater demands for backwash purposes were investigated in an existing water treatment plant. It was noticed that the period of reduction of the concentration of suspension in outflow to values as high as 800, 700, 600, 500 mg/l was correlated with the total mass accumulated in a filter. However, at the end of the backwash the suspension concentration in outflow had a more occasional character and no documented correlation existed. It was also found that the period of a filter backwash established arbitrarily by the staff of the water treatment plant depended on the total dry mass of deposit accumulated.
Biokinetics of Nitrification in the Activated Sludge Process with Bioaugmentation
Authors: Zachopoulos St. A. , Hung Y.‐T. 
Published: February 2007

AbstractA laboratory study was conducted to determine the effect of bioaugmentation on nitrification performance in activated sludge process for treating municipal wastewaters. Two continuous flow bench‐scale activated sludge systems consisting of 3 reactors each were operated for 30 months. The bacterial culture product used in bioaugmentation contained supplementary heterotrophic and nitrifying microorganisms. Parameters investigated included wastewater strength, hydraulic detention time, and sludge age in an activated sludge reactor system, which were low, medium and high strength; 6, 12, and 24 hours detention time; and 5, 10, and 20 days sludge age. A first reaction order mathematical model was developed for the nitrification process. Statistical fitting of the experimental data to the mathematical model allowed for determination of nitrification rate constant, decay coefficients, minimum aeration time required for initiation of the nitrification process, and the ability of the system to perform nitrification for the applied operation conditions. The results indicated that bioaugmentation improved nitrification at higher influent strength and at longer sludge age, did initiate nitrification earlier in the reactors, and did not affect the nitrification rate nor the decay coefficients.
Changes in Hydra vulgaris PALLAS (Cnidaria) Caused by the Effect of Torak EC 24 Insecticide
Authors: Kalafatić Mirjana , Žnidarić Danica , Lui A. 
Published: February 2007

AbstractWithin 24 h time, Torak EC 24 in 10 mg/l and 30 mg/l concentrations causes the worst damage immediately after treatment. In the treated hydras, a considerable state of contraction, a damage of tentacles and the hypostome as well as a damage of intracellular membranes and cellular organelles was observed. Besides, during the experiment, the treated hydras in both concentrations used were budding more intensely than the control.
Gas Chromatography for Determination of Pesticides in Aquatic Systems — Analytical Basis Gaschromatographie zur Bestimmung von Pestiziden in aquatischen Systemen — Analytische Grundlagen
Authors: Brauch H.‐J. 
Published: February 2007

AbstractHigh resolution gas chromatography (HRGC) with ECD, NFID and MSD is a very efficient determination method for pesticides in water. Because of their relatively low concentrations in aquatic systems enrichment and preconcentration procedures are essential. Some examples for pesticide determination by GC methods are given. Potentials and limitations of HRGC for pesticide analysis are also discussed. An extensive pesticide analysis in water has to include different methods like HRGC, HPLC and GC/MS.
Magnetpartikel‐Enzymimmunoassay als schnelle Screening‐Methode zur Bestimmung von Atrazin in Umweltproben Magnetic Particle Based Enzyme Immunoassay as a Rapid Screening Method for the Analysis of Atrazine in Environmental Samples
Authors: Dankwardt A. , Seifert J. , Hock B. 
Published: February 2007

AbstractDer Einsatz eines Magnetpartikel‐Enzymimmunoassays zur Atrazin‐Bestimmung wird vorgestellt. Der Meßbereich liegt zwischen 0.04 und 5 ppb. Der Test ist einfach und innerhalb einer Stunde durchzuführen. Variationskoeffizienten von unter 10% können erreicht werden. Es wurden Boden‐ und Wasserproben untersucht. Letztere lassen sich ohne Reinigungsschritte direkt im Test einsetzen. Matrixeffekte konnten nicht festgestellt werden. Ein Vergleich des Magnetpartikel‐Assays mit einem Mikrotiterplatten‐Assay und der GC‐Bestimmung ergab eine gute Übereinstimmung. Der vorgestellte Test ist als schnelle und empfindliche Screening‐Methode für Wasser‐ und Bodenproben verwendbar.
Investigations on the Biodegradability of Chlorinated Fulvic Acids Untersuchungen zur mikrobiellen Verwertbarkeit gechlorter Fulvinsäuren
Authors: Hambsch B. , Schmiedel U. , Werner P. , Frimmel F. H. 
Published: February 2007

AbstractMicrobial biodegradation of organic substances takes place during drinking water treatment, but also in the distribution net, if the drinking water still contains biodegradable organic substances. This phenomenon is called regrowth. The regrowth potential of a drinking water is high, when for instance ozonation is used as the last step of treatment. It was proved before, that ozonation increases the biodegradability of humic substances, which are the main fraction of organic carbon in drinking water. In this work the objective was to check, if chlorination has a similar effect on humic substances. Using the method developed by Werner of measuring the regrowth potential of a water it could be shown by dilution series with chlorinated and unchlorinated humic substances that the substrate quality of these organics is increased by chlorination. The better substrate quality is seen in the chlorinated solutions, which might contain also low molecular weight organic compounds, but also in the fulvic acid fraction after XAD‐enrichment, which removes most of the low molecular weight organic compounds. The chlorination creates in the fulvic acid solutions a shift of molecular size to smaller molecules and higher polar substances, which might be the reasons for the better biodegradability. From these results it can be concluded, that chlorination produces substances, which are more easily biodegradable. But this will not produce regrowth problems as long as there is free chlorine present as a disinfectant. In contrast, when the chlorine demand is very high and no free chlorine is left, this might produce high colony counts in the distribution net.
Degradation of Aqueous Atrazine and Metazachlor Solutions by UV and UV/H2O2 — Influence of pH and Herbicide Concentration Abbau von Atrazin und Metazachlor in wäßriger Lösung durch UV und UV/H2O2 — Einfluß von pH und Herbizid‐Konzentration
Authors: Hessler D. P. , Gorenflo V. , Frimmel F. H. 
Published: February 2007

AbstractThe degradation of two pesticides: atrazine and metazachlor was investigated in aqueous solution under UV‐irradiation with and without H2O2. Rate constants of the photochemical degradation were determined applying a first order kinetics and quantum yields of the processes were calculated. This approach leads to an apparent decrease of the quantum yield with increasing initial pesticide concentration.At low H2O2 initial concentrations, the pesticide degradation was shown to be much more efficient than the degradation under UV‐irradiation only. However, at high H2O2 concentrations (>2 mmol L−1), the efficiency of the UV/H2O2 system dropped down and the quantum yields of degradation were lower than for the direct photolysis.In the absence of H2O2, no influence of the pH value on the photodegradation of the pesticides could be noticed in a range between pH 3 and pH 11. At low H2O2 initial concentrations, the photochemical degradation of the pesticides was much faster at pH 3 and pH 7 compared with the degradation at pH 11. The results emphasize the potential of optimized reaction conditions in advanced oxidation.
Einfluß einiger Umweltfaktoren auf die N2O‐Bildung durch Belebtschlamm unter anoxischen Bedingungen Influence of Some Environmental Conditions on N2O‐Release by Activated Sludge under Anoxic Conditions
Authors: Geywitz‐Hetz S. , Bußmann M. , Schön G. 
Published: February 2007

AbstractDie Freisetzung von Distickstoffoxid (N2O, „Lachgas”︁) während der Denitrifikation in Belebtschlamm aus Kläranlagen kann durch verschiedene äußere Faktoren beeinflußt werden: Hohe Nitrat‐ und Nitritkonzentrationen steigern die N2O‐Bildung. Acetat bewirkt in hohen Konzentrationen ebenfalls eine erhöhte N2O‐Freisetzung. In Belebtschlamm wirkt Sulfid als Inhibitor der N2O‐Reduktase (wie in Böden und Reinkulturen), allerdings wird es schnell wieder eliminiert, so daß die Wirkung nur kurzfristig (ca. 2 h) anhält. Bei erneuter Zugabe von Sulfid steigt die N2O‐Freisetzung wieder an. Durch niedere pH‐Werte (unter 6.5) wird die N2O‐Bildung stark erhöht. Unter O2‐limitierten Bedingungen (0.5‐0.9 mg/L O2, 5‐10 % O2‐Sättigung) kann eine hohe N2O‐Freisetzung beobachtet werden, obwohl keine zwischenzeitliche Nitritakkumulation auftritt.
Ermittlung der Nachweis‐, Erfassungs‐ und Bestimmungsgrenze nach DIN 32645 mit Hilfe eines Programms Calculation of Detection Limit, Identification Limit and Determination Limit according to DIN 32645 with the Aid of a Computer Programs
Authors: Kolb M. , Bahr A. , Hippich S. , Schulz W. 
Published: February 2007

AbstractDie neue DIN 32645 definiert Nachweis‐, Erfassungs‐ und Bestimmungsgrenze von Analysen‐verfahren und enthält entsprechende Berechnungsformeln. Die Nachweisgrenze ist eine qualitative Aussage, erst bei der Bestimmungsgrenze ist eine quantitative Angabe möglich. Die Erfassungsgrenze ist keine Entscheidungsgrenze für die Analyse.Da der Rechenaufwand zur Ermittlung der drei genannten Parameter erheblich ist, wurde ein Programm entwickelt und am Beispiel der Herbizidanalytik mit GC‐MS nach Festphasenextraktion angewandt. Dabei zeigte sich, daß das Programm auch bei der Entwicklung von Analysenverfahren sehr nützlich ist, da es eine schnelle Überprüfung von vorgenommenen Änderungen im Analysenverfahren gestattet. Nach Optimierung des Analysenverfahrens wurden für die Herbizide Nachweisgrenzen erhalten, die etwa 10–20% des Grenzwertes der Trinkwasserverordnung betragen.
On the Toxicity and Biodegradation of Cationic Surfactants Über die Toxizität und den biologischen Abbau kationischer Tenside
Authors: Leal J. Sánschez , González J. J. , Kaiser K. L. E. , Palabrica V. S. , Comelles F. , García M. T. 
Published: February 2007

AbstractThree ammonium halide type surfactants were tested under standard laboratory condition for biodegradability and acute toxicity to Daphnia magna and in the Microtox test with the luminescent bacterium Photobacterium phosphoreum. The tested compounds are dimethyldistearylammonium chloride (DSDMAC), cetyltrimethylammonium bromide (HTMAB) and cetylbenzyldimethylammonium chloride (HBDMAC). The results indicate DSDMAC is less toxic than the other two surfactants and that it biodegrades rapidly at both lower (2.5 mg/L) and higher (10 mg/L) concentrations.
Entwicklung von Enzymimmunoassays zum Nachweis von Phenoxycarbonsäure‐Herbiziden in Trink‐ und Grundwässern Development of Enzyme Immunoassays for the Detection of Phenoxycarboxylic Acid Herbicides in Drinking Water and Groundwater
Authors: Weber W. , Rubach K. 
Published: February 2007

AbstractFür den Nachweis von Phenoxycarbonsäure‐Herbiziden in Trink‐ und Grundwässern wurden für MCPB [4‐(4‐Chlor‐2‐Methylphenoxy)buttersäure], Mecoprop [2‐(4‐Chlor‐2‐Methylphenoxy)propionsäure] und 2,4‐D [2,4‐Dichlorphenoxyessigsäure] kompetitive Festphasen‐Enzymimmunoassays mit polyklonalen Antikörpern entwickelt. Das Trägerprotein für die Immunisierung war Rinderserumalbumin, als Enzymtracer wurden Meerrettichperoxidase‐Konjugate für die Tests eingesetzt. Bei den drei Antiseren stand die Optimierung bezüglich der Nachweisgrenze und der Testempfindlichkeit im Vordergrund. Für die Mecoprop‐und 2,4‐D‐Antiseren waren der pH‐Wert und die Ionenstärke des Inkubationspuffers von großem Einfluß sowie die Verwendung von weniger affinen Enzymtracern. Das MCPB‐Antiserum reagiert mit 2,4‐DB [4‐(2,4‐Dichlorphenoxy)buttersäure] gleichermaßen spezifisch. MCPB bzw. 2,4‐DB können mit 0.02 μg/L (80% B/B0) nachgewiesen werden, der Testmittelpunkt (50% B/B0) liegt bei 0.1 μg/L. Beim Mecoprop‐Antiserum wurde die Nachweisgrenze auf 0.02 μg/L optimiert, der Grenzwert der Trinkwasserverordnung von 0.1 μg/L liegt bei 60% B/B0. Die stärkste kreuzreagierende Aktivität ging vom Mecoprop‐Methylester aus MCPB, 2,4‐DB und Dichlorprop reagieren mit 50%, 6.7% und 6.3% kreuz. Das 2,4‐D‐Antiserum reagiert mit 2,4‐D weniger empfindlich, hier liegt die Nachweisgrenze bei 0.4 μg/L. Der 2,4‐D‐Isooctylester und 2,4‐D‐Methylester zeigen als kreuzreagierende Verbindungen hohe Querempfindlichkeiten von 3630% und 2230%. Die Kreuzreaktionen der Verbindungen 2,4‐DB, MCPB und MCPA [4‐Chlor‐2‐Methylphenoxyessigsäure] betragen 520%, 69% und 41%. 100 Grundwasserproben wurden laborintern dotiert. Alle positiven Proben wurden als richtig‐positiv erkannt, falsch‐negative Ergebnisse traten nicht auf.
Characterization of Saale River Sediments by IR Spectroscopy Charakterisierung von Saale‐Sedimenten durch Infrarotspektroskopie
Authors: Hobert H. , Schulz U. , Einax J. 
Published: February 2007

AbstractThe main constituents of sediment samples of the river Saale were analysed by IR spectroscopy. The composition of the sediments is determined mainly by the geological conditions (increase of carbonates, decrease of clays along the stream). Anthropogenic influences on the main components were not recognized. IR spectroscopy connected with multivariate data treatment is a suitable method to determine the main components of sediments and soils presupposed that the particle size distribution of the samples is similar. A quantitative chemical analysis in terms of individual substances or substance groups is possible if a set of reference spectra can be compiled.
Functional Community Organization of Macroinvertebrates in Lotic Habitats of the Plitvice Lakes Funktionelle Organisation der Makroinvertebraten‐Gemeinschaft in den lotischen Habitaten der Seen von Plitvice
Authors: Habdija I. , Primc‐Habdija B. , Belinić I. 
Published: February 2007

AbstractThe community and trophic structure of benthic macroinvertebrates were studied in different types of habitats in the karstic Plitvice Lake system located in the NW Dinarid mountains (Croatia). The spatial distribution of functional macroconsumer groups shows that longitudinal community functional organization doesn't correspond with the River Continuum Concept (RCC) hypothesis. Collector guilds were the most abundant functional feeding groups at all the sites analyzed. The domination of shredders was found only in habitats in the source areas of the supply streams. The disturbed longitudinal community functional organization is caused by a discontinuum in the gradient of physical factors which is a result of the geomorphological origin of travertine barriers along the hydrosystem.
Beeinflussung der Enzymaktivität einer Protease durch Huminstoffe Influence of Humic Substances on the Activity of a Protease
Authors: Jahnel J. B. , Mahlich B. , Frimmel F. H. 
Published: February 2007

AbstractDie vorliegenden Untersuchungen zeigen den Einfluß von vier ausgewählten isolierten Huminstoffen (HS) auf die Enzymaktivität (EA) des proteolytischen Enzyms Pronase E. Die EA wird durch die Hydrolyse des Substrates Casein mit Hilfe eines Aminosäure‐Analysators erfaßt. Alle untersuchten HS führen mit steigender Konzentration zu einer stärkeren Verringerung der EA. Die Fulvinsäuren (FA) HO3 FA, FBR FA und FBR 1.0 FA wirken ab 150 mg/L enzymhemmend, während FBI‐2 FA erst bei höheren Konzentrationen die EA verringert. Am Beispiel der enzymatischen Hydrolyse von L‐Leucin‐2‐naphthylamid‐hydrochlorid in Gegenwart von HO3 FA als Inhibitor wird die aktivitätsverändernde Enzym‐HS‐Wechselwirkung als nichtkompetitive Hemmung charakterisiert.
The Role of Particulate Matter in the Mobilization of Trace Metals during Anaerobic Digestion of Solid Waste Material Die Bedeutung der partikulären Substanz für die Mobilisierung von Spurenmetallen beim anaeroben Abbau fester Abfallstoffe
Authors: Peiffer St. , Becker U. , Herrmann R. 
Published: February 2007

AbstractMetal ions bound to particulate matter represent the greatest portion (i.e. > 95%) of the total metal content found in leachate from reactor experiments where solid waste material was anaerobically digested. This seems true even though strong complexing agents are in solution which increase the solubility of Pb and Cu by a factor up to 104… 105 over that theoretically predicted according to the solubility of the corresponding sulfide mineral. A titrimetric characterization of the metal ion binding sites of the particulate matter suggests that the metal binding properties of the particulate matter are mainly due to organic, aminoacid‐type compounds (amines. thio groups, carboxylic groups) probably of bacterial origin. The change of the concentration of the binding sites with time, together with the change of the composition of the particulate matter indicates that bacterial flocs are suspended in the leachate during the switch from acidogenic to methanogenic conditions — either due to the detachment of bacterial films from the solid material by the intensive gas production or due to the formation of syntrophic methanogenic bacterial associations or a combination of both. A combination of the two factors, strong affinity of bacterial mass to metal ions on the one hand, and suspending of the bacterial mass in the leachate on the other hand, will therefore imply a great mobilizing potential for trace metals. Consequently, the highest concentrations of particulate bound Cd were found in reactor experiments where sewage sludge contaminated with Cd was added to the waste material. An increase of the concentration of dissolved cadmium over the solubility of cadmium sulfide, however, could not be observed.
Removal of Phosphate in Aqueous Solution by Permethylated Poly(ethyleneimine) Entfernung von Phosphat mit permethyliertem Poly(ethylenimin) in wäßriger Lösung
Authors: Palmer V. , Zhou R. , Geckeler K. E. , Bayer E. 
Published: February 2007

AbstractThe use of cationic, water‐soluble, permethylated poly(ethyleneimine) (PMP) for the removal of phosphate ions was investigated using the Liquid‐phase Polymer‐based Retention (LPR) technique. The results showed that the retention values were dependent on the filtration factor (Z) and pH. In the presence of 10 mg/L phosphate and 1% PMP, 52% of the phosphate was retained at pH = 1.0 and 93% at pH = 8.5 for Z = 2. However only 11% of phosphate was retained at pH = 1.0 and 80% at pH = 8.5 for Z = 5. The maximum binding capacity of phosphate by 1% of PMP was 22 mg phosphate per gram of PMP at pH = 1.0 and 185 mg phosphate per gram of PMP at pH = 7.0. The influence of nitrate, chloride, and sulfate ions on the interaction of phosphate ions with PMP was also investigated. It was found that the interaction is strongly influenced by sulfate ions. In addition, viscosimetric measurements were performed and discussed.
Polarographische Bestimmung von Nickel und Chrom in Klärschlämmen Polarographic Determination of Nickel and Chromium in Sewage Sludge
Authors: Kolb M. , Mann J. , Schäfer J. , Müller F. , Bogenschütz G. , Dengler C. 
Published: February 2007

AbstractEs wurde polarographisch der Gehalt an Ni und Cr in einem hochbelasteten und einem niedrig belasteten Klärschlamm bestimmt. Dabei wurde der DIN‐Aufschluß (Königswasser) angewandt und die erhaltene Lösung zusätzlich mit H2O2/UV (90 °C, 60 min) zur weiteren Zerstörung der organischen Matrix behandelt. Daneben wurde die Lösung des DIN‐Aufschlusses auch mit Hilfe der Flammen‐AAS bzw. ICP‐OES untersucht.Bei der Bestimmung von Ni zeigte sich, daß keine dem Königswasseraufschluß nachgeschaltete H2O2/UV‐Behandlung erforderlich ist. Dagegen ergaben sich bei der Chrombestimmung Minderbefunde, wenn der Klärschlamm nur mit Königswasser aufgeschlossen wird. Erst nach einer Photolyse (H2O2/UV) und genau einzuhaltenden Weiterbehandlungsschritten wurde eine gute Übereinstimmung mit den zertifizierten Werten bzw. den AAS/ICP‐Gehalten gefunden.