bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Physico‐Chemical Characteristics of the Used Filter Sand and its Role in the Seven Water Works Systems in a Tropical Region
Authors: Prasad D. Y. , Belsare D. K. 
Published: February 2007

AbstractThe filter‐technical equipment of seven water works in a tropical region of India is described. The structure of the filter sand layer, the grain size distribution and the degree of uniformity are compared by means of tables. The uniformity coefficient of a good filter sand is smaller than 1.7. Besides physical properties, also the surface properties of the filter sand grains are of interest. Different analytical methods for determining the incrustation are described. The amount of the filter grain load also depends on age, i.e. on the service life of the filter sand. The efficiency of a filter plant is determined also by the regeneration process, i.e. by back‐wash. This includes the methods of scouring with water only and the back‐washing with water/air.
Karpfenintensivbewirtschaftung von Seen und Eutrophierung
Authors: Kalbe L. 
Published: February 2007

AbstractIn the Galenbeck lake, a shallow lake covering 700 ha and having a nutrient load of 0.23 g/m2a P as well as 4.3 g/m2a N, in 1965 a stock of carp of 500 animals/ha was established and additionally fed with grain. This stock of carp resulted in a considerable whirling‐up and redeposition of the soft lime sediments, the rich submersed vegetation disappeared and the phytoplankton reached maxima of 885,420 cells/ml, whereas the zooplanktion reached only 4530 ind./l. The chlorophyll contents increased to 464 mg/m3, the depth of visibility decreased to 10 cm. The total planktonic primary production is estimated at 500 g/m2a C at least. These changes are regarded as eutrophication, its cause being attributed mainly to the internal fertilization by an intensified recirculation of nutrients from the sediment, but also by the fertilization which is connected with feeding. When the fish rearing had ceased and the stock of carp had been fished off, in 1970 a reacreation of the lake began, and in 1974 the lake reached again its original state as a clear‐water lake with an abundant contents of macrophytes, supported also by the P‐retention in an upstream storage reservoir for spray‐irrigation water.
Zum Leistungsvermögen makroporöser Adsorberpolymere bei der Elimination organischer Mikroverunreinigungen
Authors: Walther H.‐J. , Kaeding J. , Fechner P. 
Published: February 2007

AbstractIn laboratory experiments the adsorption of eleven different organic substances in water is individually tested in the range of concentration of 0.2… 5.0 mg/l on EP 60 and EP 61 (styrene‐divinylbenzene, non‐polar) and EP 62 and Y 59 (acrylic‐acid‐ester‐divinylbenzene, polar). In batch experiments the elimination at 1… 2 g/l adsorber quantity was 35… 80%, strongly dissociated anionic substances as benzoic acid being adsorbed only to a low degree and weakly cationic and undissociated substances being adsorbed well. Within a homologous series adsorption increases with the molar mass until the pore diameter will become too small for the taking up of substances. Under dynamic conditions (filtration technology) an elimination of 90… 100% can be expected. As a whole, the adsorption on activated carbon was better in all cases than the adsorption on the polymers. The desorption for the regeneration of the polymers is the more difficult the better the substance contained is adsorbed. By repeated loading and regeneration only a slight influence on the adsorption and desorption of a substance was found.
Zur Analytik von Chlorphenoxyalkansäuren und Chlorphenolen. Teil 2: Nachweis von Chlorphenoxyalkansäuren und Chlorphenolen in der Fischgalle
Authors: Grahl K. , Hermenau H. 
Published: February 2007

AbstractThe bile liquid is preserved with ethanol and the protein is precipitated. Prefractionating is done by liquid‐liquid extraction by chloroform and ethyl acetate. The extracts are column‐chromatographically separated on Florisil and subsequently detected by thin‐layer chromatography. For determining the identity of substances, the penta fluorobenzyl derivatives are prepared and chromatographed under the same conditions. Detection is carried out with the aid of ammoniacal silver nitrate reagency and ultraviolet irradiation. The highly polar conjugates of chlorophenoxyalkane acids and chlorophenols which are present in the bile are cracked by acid hydrolysis and then cleaned by re‐extraction. In this way, 2, 4‐D, MCPA, MCPP, 2,4‐dichlorophenol and 2‐methyl‐4‐chlorophenol were detected from Salmo gairdneri. 6… 21 d after the application of the herbicides in the catchment area their concentration in the fish bile amounted to about 200 mg/l, 90% of them having been conjugates. Thus, the biliary excretion of xenobiotic substances offers an important new aspect of biomonitoring by means of fish tests, especially in the range of subacute and chronic toxicity.
Die Desinfektion von Trinkwasser — ein kritischer Überblick
Authors: Stachel B. , Gabel B. , Lahl U. , Zeschmar B. 
Published: February 2007

AbstractIn the chlorination of drinking water about 90% of chlorine show an oxidizing effect, 10% result in halogenated reaction products, ca. 1% of them consisting of trihalomethanes. When chlorine dioxide is applied, in most the trihalomethanes remain below the detection limit, but increasingly polar organic reaction products originate, on the other hand. Chloramine is rarely applied, mostly for securing transport with storage reservoir waters. Only little information about reaction products is available. By the application of ozone one obtains a wide spectrum of reaction products, the aldehyde contents can be influenced by activated carbon. Especially critical is the formation of persistent epoxides, above all from pesticides. Due to antimon burners, the ultraviolet irradiation is gaining in interest, and in many cases its biocidal effect is superior to that produced by chlorination and ozonization, except for the problem of re‐germination in the water supply network. The costs of ultraviolet irradiation, however, are much higher than those of the other techniques, of which chlorination causes only about one quarter of the costs of the other chemical disinfection techniques.
Möglichkeiten der Nachreinigung von Abwässern aus der Kunstlederproduktion mit Hilfe von Algen, Teil 2
Authors: Chromek J. , Kupec J. , Marvan P. , Mládek M. 
Published: February 2007

AbstractThe attempt was made to use the alga Scenedesmus quadricauda for the purification of wastewaters from the production of artificial leather. The dimethylamine contained in these wastewaters is continuously decomposed and the remaining nitrogen‐containing residuals are used as a nutrient source for the production of algal biomass. In continuous experiments with original wastewaters, dimethylamine and its metabolites showed a pronounced inhibiting effect. In practice, a longer retention time in the reactors as well as a sufficient share of municipal wastewater are required in order to avoid a limiting of growth due to a phosphorus deficiency. The second part of this paper is concluded by information about other investigations performed by us on the purification of artificial leather wastewaters with the aid of the biological nitrogen elimination under specific conditions with a successful denitrification of up to 95%.
Zur Veränderung der Bestände von Phragmites australis (CAVANILLES) TRINIUS ex STEUDEL (Phragmites communis TRINIUS) im Breiten Luzin bei Feldberg (Mecklenburg)
Authors: Richter W. M. 
Published: February 2007

AbstractThis paper represents the documentation of phragmites stocks by means of photographic records with a panoramic camera (120°/45° angular coverage, f 28 mm, 1 : 2.8). There are demonstrated the changes in the stock of reed due to grazing, boat traffic, entering from the bank and passing at the back as well as the weakening of stocks under the influence of increasing nutrient contents in the water. The method allows a very efficient inspection and documentation of the hatching strips and their changes.
Untersuchungen zur Phosphataufnahme durch Unterwasserpflanzen
Authors: Kussatz C. , Gnauck A. , Jorga W. , Mayer H.‐G. , Schürmann L. , Weise G. 
Published: February 2007

AbstractThe uptake of phosphorus by Potamogeton pectinatus, P. lucens, Ranunculus fluitans, Elodea canadensis, Myriophyllum spicatum and Ceratophyllum demersum is investigated in batch tests at 0.02, 0.04, 0.4 and 4.0 mg/l PO in the medium for 4, 28 and 52 h. Uptake is strictly dependent on concentration, a saturation function being discernible already after 52 h. At rising concentration the mechanism of uptake is determined by a decreasing rate of incorporation. The rates of uptake are dependent also on the actual and maximum cell nutrient contents. Species with a low phosphorus content of <5 mg PO/g dry weight as Elodea canadensis, Potamogeton pectinatus and Myriophyllum spicatum show their maximum phosphorus incorporation at low substrate concentrations. At phosphorus contents >5 mg PO/g dry weight the phosphorus incorporation is increased only at substrate concentrations of 0.04… 0.4 mg/l PO.
Humic Acids in the Inflows to the Fláje Reservoir after Deforestation of its Watershed
Authors: Micka J. , Fiala L. , Chalupa J. 
Published: February 2007

AbstractToday only 35% of the catchment area are covered by forests after deforestation, as compared with the original 70%. In connection with that, the concentration of humic matter has decreased from the original 8 mg/1 to 4 mg/1. The analysis of these changes is facilitated by the linear regressions of a high significance which exist between the COD‐Mn and humic acid concentration and the colour. Parallel to deforestation, also the nitrate concentration increased, which, however, can be explained by higher nitrogen concentrations in precipitation.
Acute Toxicity of Distillery Effluent on a Freshwater Fish and Three Pond Snails
Authors: Khangarot B. S. , Rao P. S. , Shekhawat S. S. , Durve V. S. 
Published: February 2007

AbstractThe LC50for 12… 96 h of a distillery waste water were determined forLebistes reticulatus, Lymnaea luteola, Lymnaea acuminataandViviparus bengalensisin the batch experiment with daily exchange of the medium. The sensitivity of the species increases in the given sequence with values of the LC50,96 hof 10.77 to 3.72 % proportion of wastewater in the medium. Compared with this, with values of the LC50,48 hof 14.06… 15.71 % after 48 h of exposure there is no significant difference in sensitivity, whereas after exposure for 12 and 24 h the sensitivity grows in the following order:V. bengalensis, L. acuminata, L. luteola, Lebistes reticulatus. Toxicity is obviously primarily determined by the sulphides; with increasing time of exposure also the suspended matter and other factors act toxically.
The Influence of the TTC Concentration on the Determination of Activated Sludge Activity
Authors: Miksch K. 
Published: February 2007

AbstractFor a correct determination of the activated sludge activity with the aid of TTC an optimum TTC concentration is required not only in the solution, but also as related to the biomass. Since TTC has toxic effects on bacteria, the selection of the optimum TTC concentration is connected with problems: in the suboptimal range the TTC concentration as referred to the existing bioactivity is too low, in the supraoptimal range the toxic effect does not permit any correct determination of activity. A generally optimum range cannot be stated due to the very different activities and sensitivities of the present bacterial populations. Therefore, the application of the TTC methods requires the simultaneous parallel application of different TTC concentrations and the determination of the activity in the plateau range of the relation between the TTC concentration and the formazan concentration formed.
Zytotoxikologische Untersuchung von Schadstoffen und Wasserblüten mit gefrierkonserviertem Bullensperma (Spermatest)
Authors: Kalbe L. , Recknagel R.‐D. 
Published: February 2007

AbstractThe method is based on the determination of the number of the nonmotile sperms and/or the lethally damaged sperms with the aid of the fluorescent dye primuline. Incubation takes place at a suspension density of 10.000/mm3… 38.000/mm3, at 40°C or 46 °C for 15… 60 min. During the test with sublimate the loss of motility amounts to 55% at 4 mg/l Hg2+, the LC50 is 7.3 mg/l Hg2+. Phenyl‐mercuric acetate causes the total loss of motility with 20 mg/l, the LC50 is above 168 mg/l (equivalent to 100 mg/l Hg2+). The LC50 of sodiumpentadecylmonosulphonate and dodecylpyridinchloride are 11.6 and 15.8 mg/l, resp. Filtrates of blooming of cyanophyceae on Baltic, having been digested by repeated freezing and thawing, with 1.5… 6.4 g/l dry matter showed motility losses of 30… 100 % for Nodularia spumigena, whereas no significant effect was produced by a filtrate of Microcystis aeruginosa with 28.2 g/l dry matter as well as water‐blooming of Nodularia spumigena from the Small Jasmund Bodden.
Zur indirekten Ermittlung von Selektivitätskoeffizienten für Ionenaustauschreaktionen
Authors: Ender V. , Bosholm J. 
Published: February 2007

AbstractA relation is derived for the calculation of unknown selectivity coefficients from unknown values of tertiary reactions and its validity is proved by experimental investigations of the systems H+/Na+/Ca2+, H+/Na+/Co2+ and H+/Na+/Al3+ at the strongly acid cation exchanger Wofatit KPS.
Water Quality Control by Means of Measuring the Specific Electrolytic Conductivity
Authors: Rummel W. 
Published: February 2007

AbstractResults of investigations on the basis of series of measurements having been performed for many years on the electrolytic conductivity in several waters with different degrees of pollution have shown a good correlation between residue from evaporation and conductivity. For concentrations of more than 2500 mg/l chloride these functional relations loose their validity. Because of this finding, the routine investigations of the residue from evaporation in the laboratory were stopped. Comparative measurements of residue from evaporation and conductivity which were repeated after a few years indicated deviations between 0.5 and 8 %. Limited artificial additions of salt, acid, base and thawing salt caused linear changes of the conductivity of the water samples, so that in continuous water quality control systems respective disturbances will be automatically signalled and transmitted and the extent of the pollution can be determined quantitatively with the aid of integral calculus.
Zur ökonomischen Bedeutung der biologischen Selbstreinigung
Authors: Tümpling W. V. 
Published: February 2007

AbstractIn twelve flowing water (Q 1.04… 30.4 m3/s, 0.5… 1.2 m/s) the self‐purification efficiency in 110 river sections (L 1.3… 26.4 km) is determined as the load difference in kg · d−1 COD‐Mn as well as in g · m−3 referred to the daily passage. In the economical comparison, the self‐purification efficiency is valued as substitution for wastewater treatment plants of the same capacity. At a mean specific capacity of 8.6 g · m−3, the self‐purification efficiency of the investigated waters is equivalent to economical values of 124 · 103… 534 · 103 M km−1 investment costs, 11 · 103… 80 · 103 M · a−1km−1 operating costs and 5… 81 MWh · a−1 km−1 expenditure of energy. The specific capacity in g · m−3 COD‐Mn shows an exponential regression to the degree of saprobity (L = 0.015 · exp (1.7358 · S)). From this empirical model the limits of the self‐purification capacity of aerobic waters by oxygen input can be detected: in respective examples more than 50% of the required oxygen input are due to weirs.
Anforderungen an die Gütebewirtschaftung von Oberflächengewässern in tropischen und subtropischen Klimaten
Authors: Uhlmann D. 
Published: February 2007

AbstractA survey is given of the special conditions and their effects by means of a large number of examples. There should be pointed out especially the possible mass development of higher aquatic plants, partly high concentrations of turbidity‐causing substances, the lack of oxygen even at slight water depths as well as the often high contents of pathogenic agents and a pronounced thermal stratification in storage reservoirs. Conclusions for the quality management are derived.
Stand der einheitlichen Wasseranalytik in der DDR
Authors: Legler Ch. , Breitig G. 
Published: February 2007

AbstractUniform analytical methods for water investigations have been available in the GDR since 1957 (chemistry) and 1961 (biology). The AUSGEWÄHLTEN METHODEN DER WASSERUNTERSUCHUNG (Selected Methods of Water Analysis) published between 1970 and 1976 in several parts of two volumes were based upon analytical methods which had been co‐ordinated within the framework of the Council of Mutual Economic Aid. The chemical, physicochemical, physical and electrochemical methods (vol. I) and the biological, microbiological and toxicological methods (vol. II) compiled here are obligatory by the technical standard TGL 28400 „Wasseruntersuchungen — Grundsätze zur Untersuchungsmethodik”︁ (water analyses—principles for the analytical methods). Now a survey of the further development of this collection of methods is given by the authors in their second edition of 1982 (vol. II) and 1985 (vol. I).
Zur Elimination organischer Verbindungen durch Adsorberpolymere
Authors: Walther H. J. , Kümmel R. , Worch E. , Tsaussides E. , Hellmig R. 
Published: February 2007

AbstractAn investigation is made into the performance of a commercial product (Wofatit EP 61) and of newly‐developed experimental samples of macroporous adsorption polymers (copolymers of styrene and divinyl benzene) with a much larger specific surface in batch and filter experiments. Against organic adsorptives having the character of weak electrolytes, adsorption polymers show a significantly pH‐dependent elimination capacity. Non‐ionic or only weakly dissociated anionic adsorptives are removed by the experimental samples to a much higher degree than by the commercial adsorption polymer. Highly dissociated anionic compounds can be removed by activated carbon better than by macroporous adsorption polymers.
Biochemische Abbaubarkeit ausgewählter alicyclischer Verbindungen
Authors: Wotzka J. , Giest B. , Pfitzner St. 
Published: February 2007

AbstractThirteen alicyclic compounds (C5… C7) are examined for their biochemical degradability in a laboratory activating tank and in two respirometers (Warburg, Sapromat). The tests were performed with adapted and nonadapted activated sludge. In addition, the COD was determined by three different methods. With the exception of cycloheptane (BOD < 25% of the BODtheor.), six compounds prove to be easily degradable (BOD > 45% of the BODtheor.) and six compounds prove to be degradable (BOD 45… 25% of the BODtheor.).
Langzeitveränderungen essentieller Nährstoffe in der zentralen Ostsee
Authors: Nehring D. 
Published: February 2007

AbstractThe continuing phosphate accumulation with 0.04… 0.075 μmol · 1−1 · a−1 in the deep water and 0.024… 0.026 μmol · 1−1 · a−1 in the winter‐time surface layer of central Baltic Sea stations is confirmed by the continued previous investigations. After an increase the nitrate concentrations in the deep water decreased significantly between 1979 and 1982, which is obviously due to denitrification processes caused by unfavourable oxygen conditions in the boltom water. In the Fårö Deep and in the Landsort Deep a significant correlation between nitrate and oxygen concentrations was found. In the winter‐time surface layer, for the nitrate a positive trend prevailed with 0.148… 0.225 μmol · 1−1 · a−1, which was in close correlation with an increase in salinity. This eutrophication is caused by the prevailing anthropogenic influences and also by oceanological changes as the decrease in the stability of stratification in the Gotland Deep with an intensification of the vertical exchange of matter. Consequences of eutrophication consist in the increase of the biomass of zooplankton and zoobenthos and in the yields of the Baltic Sea fisheries, but also in the increased loading of the oxygen balance causing longer anoxie periods in the deep water.
Effects of Chronic Exposure to Sublethal Doses of Two Pesticides on Alkaline and Acid Phosphatase Activities in the Intestine of a Fresh Water Teleost, Channa striatus BL. (Channidae)
Authors: Arora N. , Kulshrestha S. K. 
Published: February 2007

AbstractThe effects of chronic exposures to sublethal concentration of two pesticides Carbaryl and Endosulfan on alkaline and acid phosphatase activities in the intestine of a fresh water teleost Channa striatus have been observed by exposing the fish for a period of two to thirty days to 10 ppm and 20 ppm of Carbaryl and 0.00075 and 0.001 ppm of Endosulfan. The inhibition of alkaline phosphatase activity has been dependent on the duration of exposure, concentration and the type of pesticide used. The acid phosphatase activity increased with the duration of exposure in higher concentration of Carbaryl and both the concentrations of Endosulfan. Endosulfan produced more pronounced effects than Carbaryl.
On the Kinetics of Denitrification. Part 4: Studies on Denitrification with the pH Auxostat
Authors: Bürger G. , Behrens U. 
Published: February 2007

AbstractContinuous denitrification was investigated in the system acetate medium—mixed culture with the pH auxostat. The cultivation method was applicable under defined conditions. The maximum specific growth rate obtained was 0.37… 0.38 h−1. A comparison with data from the chemostat was performed.
Occurrence and Chemistry of Zinc in Freshwaters – its Toxicity and Bioaccumulation with Respect to Algae: A Review Part 2: Toxicity and Bioaccumulation with Respect to Algae
Authors: Vymazal J. 
Published: February 2007

AbstractZinc has definitely been established to be required for the growth of both higher plants and algae, but it can act either in a stimulatory mode or in an inhibitory one, depending on its level of availability. A variety of environmental factors are known to modify the toxicity of zinc in water on algae. It has been observed that algae differ in their tolerance to zinc.It is well known that algae can accumulate zinc or other metals from water, producing an internal concentration greater than in their surroundings. The modes of accumulation and concentration factors are given.
Effect of synthetic fertilizers and atmospheric precipitation on nitrogen enrichment in surface waters
Authors: Beneš J. , Boehmová M. , Fiala L. , Veselý M. , Vokounová E. 
Published: February 2007

AbstractThe increase of the nitrate concentration in surface waters used as water supply resources has been investigated with a view to the effects of agricultural activities and atmospheric precipitation. The nitrate concentration increased beyond the acceptable limit for infants after 1975, when due to the permanent augmentation of the synthetic fertilizer rates the organic humus quantities decreased to a minimum. The variability of nitrate concentrations in atmospheric precipitation is dependent on the magnitude of precipitation and the intensity of industry in the given region. At an average value of atmospheric precipitation the nitrogen value in agricultural regions varies within 6 to 12 kg · ha−1 · a−1, in regions with extended industries up to 24 kg · ha−1 · a−1.