Zur Adsorption von Dichlormethan und 1,1,1-Trichlorethan aus Modellabwässern mit Adsorberpolymeren und Aktivkohlen

Adsorption of Dichloromethane and 1,1,1-Trichloroethane from Synthetic Wastewaters with Polymeric Adsorbents and Activated Carbons Isotherms, kinetics, and dynamics of adsorption of dichloromethane and 1,1,1-trichloroethane from synthetic wastewaters onto novel polymeric adsorbents were investigated in comparison to traditional polymeric adsorbents and activated carbons. The polymeric adsorbents and the activated carbons showed no large differences in adsorption kinetics, whereas the novel, crosslinked polymeric adsorbents exhibited at times higher adsorption capacities than the traditional, not crosslinked polymeric adsorbents and activated carbons.     

Untersuchungen zur adsorptiven Abtrennung von leichtflüchtigen chlorierten Kohlenwasserstoffen (LCKW) aus huminstoffhaltigen Wässern mit neuartigen Adsorberpolymeren

Investigations of the Adsorptive Separation of Volatile Chlorinated Hydrocarbons (VCHC) from Water with Humic Substance by Novel Polymeric Adsorbents and Activated Carbons. Part I: Isotherms and Kinetics of Adsorption The isotherms and kinetics of adsorption of different volatile chlorinated hydrocarbons (VCHC) (1,2-dichloroethane, 1,1,1-trichloroethane, trichloroethene) and a humic substance from water as well as these VCHC from water with humic substance onto novel polymeric adsorbents (WOFATIT EP 63, DOWEX XUS 43493 and XUS 43546, MACRONET MN 100 and MN 200) were studied in comparison to activated carbons (NORIT ROW 0.8 SUPRA, PRECOLITH BKK 3, HYDRAFFIN CG). It was determined that the novel polymeric adsorbents remove the VCHC well and the humic substance in contrast to the activated carbons only a few. The decrease of the equilibrium loading for the VCHC due to the presence of humic substance is at the activated carbons approximately double as high as at the novel polymeric adsorbents, whereas in the kinetics of adsorption no substantial influences of the humic substance on the mass transfer were determined.     

Untersuchungen zur adsorptiven Abtrennung von leichtflüchtigen chlorierten Kohlenwasserstoffen (LCKW) aus huminstoffhaltigen Wässern mit neuartigen Adsorberpolymeren und Aktivkohlen. Teil II:: Dynamik der Adsorption

Investigations of the Adsorptive Separation of Volatile Chlorinated Hydrocarbons (VCHC) from Water with Humic Substance by Novel Polymeric Adsorbents and Activated Carbons. Part II: Dynamics of Adsorption In this publication, the dynamics of adsorption of different volatile chlorinated hydrocarbons (VCHC) (1,2-dichloroethane, 1,1,1-trichloroethane, trichloroethene) and a humic substance from water as well as of these VCHC from water with humic substance onto novel polymeric ad-[QJ][HR] sorbents (WOFATIT EP 63, DOWEX XUS 43493, MACRONET MN 100 and MN 200) was studied in comparison to activated carbons (NORIT ROW 0.8 SUPRA, PRECOLITH BKK 3, HYDRAFFIN CG). The obtained breakthrough curves and the following predicted characteristic values reveal that the polymeric adsorbents do not remove or remove the humic substance only with low adsorption capacity in contrast to the activated carbons. At the adsorption of the VCHC from water with humic substance it was determined that the influence of the humic substance on the adsorption capacity is substantially less on polymeric adsorbents than on activated carbons.     

Adsorptive Separation of 1, 2‐Dichloroethane from Model Wastewater by Natural Clinoptilolite

The adsorptive separation of 1, 2‐dichloroethane from model wastewater by different Slovak natural and octadecylammonium‐modified clinoptilolites has been studied. It was found that the 1, 2‐dichloroethane will be adsorbed by natural as well as by surfactant‐modified clinoptilolites; all clinoptilolites have a similar adsorption loading. There was also no remarkable difference between the natural and surfactant‐modified clinoptilolites in respect to the adsorption kinetics.     

Zur Bildung von Artefakten und deren Vermeidung bei der Bestimmung leichtflüchtiger Halogenkohlenwasserstoffe in Wasser mittels Headspace-Gaschromatographie unter den Bedingungen der DIN 38407 Teil 5 (DEV-F5). Teil I: Bildung von Dehydrohalogenierungsprodukten aus gesättigten LHKW

Formation of Artefacts and its Suppression during the Determination of Volatile Halogenated Hydrocarbons in Water by Means of Headspace Gas Chromatography under the Standard Conditions of DIN 38407-F5. Part I: Formation of Dehydrohalogenation Products from Saturated Halogenated Hydrocarbons Under the conditions recommended by DIN 38407-F5 for the headspace gas-chromatographic determination of volatile halogenated organic substances in water (equilibration at 60…80°C for a least 60 min) several halocarbons are degraded by dehydrohalogenation resulting in the formation of unsaturated artefacts with one halogen atom less. Thus pentachloroethane and 1,1,2,2-tetrachloroethane are decomposed to form tetrachloroethylene and trichloroethylene, respectively. This leads to low results of the analytes and to false-positive detection of the reaction products. The unwanted degradation reactions can be reduced by decreasing the temperature and duration of equilibration, and they are completely suppressed by acidification of the samples.     

Über das Vorkommen von R-Plasmiden in Escherichia coli und koliformen Keimen aus Wasser und Abwasser Teil 1: Einführung und Bedeutung der übertragbaren Chemotherapeuti-karesistenz bei gramnegativen Keimen aus Wasser und Abwasser

Plasmids have been known for about 20 years. Meanwhile, there have been selected different species of bacteria, as Shigella, Salmonella, Gonococci and Haemophilusinfluenzae strains with a plasmid-infected resistance. The share of resistant microorganisms has increased due to the application of chemotherapeutic agents in the human and veterinary medicine and in the flora. As can be proved, the application of liquid manure on large areas and its frequently observed introduction of wastewater — also from hospitals — contribute to the distribution of the plasmids (resistance plasmids) in the environment.     

Nitrifikation – Grundlagen des Stoffwechsels und Probleme bei der Nutzung von Ammoniakoxidanten

Nitrification – Fundamentals of the Metabolism and Problems at the Use of Ammonia Oxidizers From an ecological point of view, a great problem results from the release of increasing amounts of inorganic and organic nitrogen compounds. Apart from gaseous nitrogen compounds, such as the greenhouse gas N₂O, soluble nitrogen compounds such as ammonium cause difficulties. In recent years, great progress has been made regarding the reduction of the emission of sulfur and phosphorus compounds. Since there are no effective strategies for the decrease of nitrogen releases, the emission of such compounds has even been increasing. Therefore, great efforts are being made to eliminate the soluble nitrogen compounds in particular, for example in wastewater treatment plants. A decisive meaning befits the chemolithoautotrophic ammonia oxidizers. This review focuses on the ecological consequences of the release of ammonia in particular, the metabolism of the ammonia oxidizing microorganisms under consideration of the latest research results, and the problems that arise in the context of using these bacteria for the removal of ammonia.     

Zur Bildung von Artefakten und deren Vermeidung bei der Bestimmung leichtflüchtiger Halogenkohlenwasserstoffe in Wasser mittels Headspace-Gaschromatographie unter den Bedingungen der DIN 38407 Teil 5 (DEV-F5). Teil II: Überhöhte Trihalogenmethanbefunde in gechlortem Schwimmbeckenwasser

Formation of Artefacts and its Suppression during the Determination of Volatile Halogenated Hydrocarbons in Water by Means of Headspace Gas Chromatography under the Standard Conditions of DIN 38407-F5. Part II: Increased Trihalomethane Formation in Chlorinated Swimming-pool Water A comparison of two analytical standard procedures for the determination of trihalomethanes (THM) in water (headspace gas chromatography and pentane extraction/gas chromatography) yielded strongly differing results. Under the conditions recommended by the German Standard Method DIN 38407-F5 (60…80°C for at least 60 min) degradation of thermo-labile chlorination products occurs resulting in elevated THM concentrations. The reactions involved are partly pH-dependant, and these can be suppressed by sample acidification. The degradation of trihalogen acetic acids, however, can only be influenced by minimizing the equilibration time and temperature. Other intermediate chlorination products (haloacetonitriles) are also degraded to THM after preceding hydrolysis to the corresponding carboxylic acids. Comparative results obtained with a purge and trap method at ambient temperature, i.e. without thermal stress during the enrichtment step, are lower than with static headspace GC but still high in comparison to the pentane extraction method. Presumably volatile THM-precursors are also trapped and subsequently decomposed upon thermal desorption from the trap. As the static headspace GC is the most rational method of LHKW determination available, the recommended experimental sample handling conditions should be modified in a way that deterioration reactions are reduced as far as possible.     

Gewässergütebewertung und Bewertung von Abwasserfahnen in Rhein und Main auf der Basis mikrobieller Enzymaktivitäten

Quality Mapping of Surface Water and Assessment of Treated and Untreated Waste-water Inputs into the Rhine and Main River Based on Microbial Enzyme Activities Microbial enzyme activities are used for an extension of the traditional quality mapping of surface water. In the following study, the enzymatic parameters were proved and validated on samples from various creeks and rivers in Baden-Württemberg and on samples gathered from the Rhine and Main Rivers (Germany). The test parameters should also be used for the control and the preservation of the capacity of the biological self-purification, which is the only natural and essential process in drinking-water conditioning of surface water. Main subject of the surveys was the development of criteria for an assessment of the measured enzymatical inhibition effects. Therefore, classes of inhibition and indices of inhibition are defined.     

Untersuchung der Anwendungsmöglichkeiten von einigen komplexbildenden Ionenaustauschern zur Kupferabtrennung aus natürlichen Wässern und Abwässern

Application of Some Complexing Ion Exchangers for Copper Recovery from Natural Water and Wastewater The rational use of water resources is one of the urgent environmental control problems. These problems can be solved by the treatment of sewage. Removal of different non‐ferrous heavy metal ions from wastewater is of great importance. Besides, the selective complexing ion exchangers are of interest because of their good sorption properties. The present paper is devoted to the study of some complexing resins for copper recovery from natural water and sewage. The following carboxylic resins were studied: the cation exchangers KB‐2T, KB‐4 and the amphoteric ion exchangers ANKB 35, AMF‐2T, and AMF‐2S (manufacturer – “TOKEM” company, Kemerovo, Russia). The exchangers investigated differed from each other both by their functional groups and by their matrix physical structures. The copper recovery from CuCl₂‐, CuSO₄‐, and Cu(NO₃)₂‐solutions was studied in batch‐experiments (in presence of NaCl, Na₂SO₄, and NaNO₃). The initial copper concentration in the solutions was 0.0002...0.008 mol/L; pH values were 1.0...5.0. After equilibrium (24 h) the resins were separated from the solution. The copper concentration in the solutions after the sorption was determined by the photometrical method with pyridylazoresorcin (λ = 500 nm). On the basis of the experimental data distribution ratio, the separation factors, equilibrium constants, and stability constants of copper complexes in the exchanger phase were calculated. It was found out in this work that the amphoteric ion exchanger AMF‐2T of macroreticular structure is the most effective for the copper sorption from sewage.     

Feinauflösung von UV-Spektren durch Differentiation 1. und 2. Ordnung im Rahmen der Kohlenwasserstoffanalyse

Fine Resolution of UV Spectra by Differentiation of 1st and 2nd Order in Hydrocarbon Analysis Basic UV spectra (0th order) in unpolar solvents such as cyclohexane are useful — though with some reservations — in characterizing mineral oils occuring in pure form and aromatic fractions in environmental samples separated by chromatographic techniques. The common standard raffinates, biogenic hydrocarbons or other mixes of hydrocarbons including polycyclic aromatics can be approximately identified. The spectra of 1st and 2nd order improve the reliability of the results and permit above all to detect polycondensated aromatics even in traces. Finally, partial spectra of 1st and 2nd order in the wavelength ranges 205…240, 220…260, and 260…320 nm allow because of their very specific structures a simple and fast practically definite assignment to the above-mentioned groups of aromatics. Analogously, substituted aromatics in detergents and other technical products have already been identified. The method is suitable as a fast preliminary test, at least.     

Beschreibung der Desorption von Zink aus Flußsedimenten mittels Freundlich- und Langmuir-Isothermen Mathematical Description of the Desorption of Zinc from River Sediments by NTA Using Freundlich and Langmuir Equations

Remobilization of zinc from sediments from Rhine and Neckar rivers with nitrilotriacetic acid (NTA) in water has been studied in order to obtain a mathematical relation between quantities of mobilized zinc on sediments and concentration of zinc and NTA in aqueous solution. Remobilization has been measured by stirring the sediments for 70 hours in polyethylene flasks and analyzing dissolved zinc by AAS. Concentration of free zinc ions in solution is correlated with amount of zinc fixed on the sediments in form of adsorption equations by Freundlich and Langmuir and the linear equation. Whereas for the Rhine river sediment all correlations are of similar quality, the standard deviation for the linear correlation with the Neckar sediment is about twice as large as for the others. The adsorption energies on both sediments are similar, however, the adsorption capacity and therefore, the remobilized amount of zinc is larger for the Rhine sediment. For mathematical modelling of technical processes, eg., for technical decontamination of sediments the linear correlation may be recommended.     

Untersuchung der Sorptionseigenschaften des Kationenaustauschers KB-2M mit Makronetzstruktur zur Abtrennung von Zinkionen aus Ab- und Spülwässern

Study of Sorptional Properties of the Cation Exchanger KB-2M with Macroreticular Structure for Recovery of Zinc Ions from Sewage and Rinsing Water Although a number of ion-exchange methods have been employed for the recovery of some transition metals from industrial effluents, knowledge about ion-exchange resins with macroreticular structure is poor. The present paper describes the mechanism of sorption on such exchangers and their application for recovery of zinc from sewage rinsing water. Ion exchanger of macroreticular structure are polymers with long-chained cross-linking agents. We have synthesized carboxylic ion-exchange resins by hydrolysis of copolymerisates of methyl acrylate with different cross-linking agents: divinylbenzene, divinyl sulfide, divinyl ester of ethylene glycol and divinyl ester of di- or triethylene glycol. The sorption process on modifications of the carboxylic resins KB-2 of various structure was studied with different methods: potentiometric titration, infrared spectroscopy, electron microscopy, X-ray structural analysis. The initial zinc concentration in rinsing water was 0.05 mol/L at pH from 3 to 6. For the sorption, 0.2…1.0 g of resin were equilibrated with 100 mL of zinc solution. After equilibrium (12 h), the resin was separated from solution. The zinc ions were determined by atomic absorption spectrometry after stripping with 100 mL of 10% sulfuric acid. The distribution ratio D was calculated (D: mmole of Zn sorbed per gram of resin divided by mmole of Zn per millilitre of solution). By means of infrared spectroscopy, the mechanism of sorption of zinc ions from rinsing water was determined. There may be a possibility of the formation of complexes in the cation-exchange resin phase. It was found out in this paper that the cation-exchanger KB-2M of macroreticular structure is the most effective for the sorption of the Zn²⁺-ions from sewage and rinsing water.