Untersuchungen zur Bestimmung und zum Vorkommen des Thiocyanats im Wasserkörper der westlichen Ostsee

For the gas-chromatographic determination of thiocyanate in waters two enrichment processes were used: 1) the evaporation of the water sample on the water bath and 2) the adsorptive enrichment on Wofatit EA 60. As the example of the investigation of water samples from the Baltic Sea has shown, the less selective process 1 gave higher results of measurements than the adsorptive method 2. As compared with the GDR's coastal region of the Baltic (0.4 … 5.2 μg/l), the SCN^? concentrations (1986) in the western offshore region (0.1 … 2.1 μg/l) are considerably lower. With increasing depth and growing salt content the SCN^? concentration in the Baltic decreases. Anthropogenic influences, such as the input of residual products of sewage works effluents, can be inferred from the relatively increased SCN^? concentrations in the coastal region.     

Zur ökonomischen Bedeutung der biologischen Selbstreinigung

In 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.     

Grundwasserchemismus im Bezirk Neubrandenburg. Teil 3. Jodid im Grundwasser

The iodide contents in 389 ground-water-tapping plants of the county are compared with the geological character of the aquifer, the carbonate and non-carbonate hardness and the nitrate and chloride contents of the waters. 54% of the plants have I-concentrations of 3 … 7 μg/l. In the air-covered ground-water (hardness quotient<2.8) 2 … 50 μg/l I are found, whereas in the confined ground-water (hardness quotient >2.8) 2 … 50 μg/l I are contained. In general, the I-content increases with the carbonate hardness, a connection with till existing. Therefore, ground-waters of the Miocene have relatively low salt- and I-contents. Geogenic salt influences in the form of NaCl increase the I-contents to 50 … 100 μg/l. Anthropogenic influences in the residential area and due to waste increase the Cl^?- and I^?-concentrations. There were not detected any dependences between the I- and NO₃-contents.     

ClT-3 — ein neues Gerät für die Chloridbestimmung in der Wasseranalytik

The device is used for the coulometric titration of chloride with electrolytically generated silver ions and biamperometric end-point indication via a second pair of silver electrodes. The device consists of the external measuring cell with the generator- and indicator-electrode systems and a magnetic stirrer as well as the titrator proper, which contains all electric and electronic components for the realization of the course of measurements up to the digital display of measured values. Four modes of operation can be chosen with the units mmol/1 Cl^? or mg Cl^? in 100 ml sample and sample volumes of 50 μ and 200 μl the compensation of systematic dosing errors or the taking into account of constant matrix effects being possible by means of a steplessly adjustable correction factor between 0.95 and 1.05. The measuring range is 25 … 2,000 mg/1 Cl^? with variability coefficients between 0.3 and 3% if a microlitre pipette with a PE pipette tip is used. An even lower variability of the results can be expected from an improved sample dosing Disturbances caused by ions subject to electrolytic redox processes were detected (Fe, S^2?, CrO₄^2?).     

Der Einfluß von Erdölkohlenwasserstoffen auf die Primärproduktion des Donauplanktons

Danube river water samples were saturated with mineral oil, and then the primary production (gross) was determined by means of the light-dark bottle method (oxygen) in situ at depths of 0.1… 1.5 m in comparison with untreated samples. Samples were exposed for half a solar day alternately during the first and second half-days. Investigations carried out between March and October for periods of 14 days showed a mean production of 2.56 g · m^?2d^?1 O₂, which was reduced by 36% due to 12.6 mg/l hydrocarbons. Production decreases with the water depth from 6.2 to 0.9 mg · l^?1d^?1 0₂, whereas the inhibition by hydrocarbons increases from 31 to 41%.     

Studies on Primary Productivity and some Hydrochemical Aspects of a Polluted Water-body of the Himalayan Jhelum Valley

The lake without any outlet (11 ha, 55000 m³, z_max 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.     

Biological effects of anthropogenic salt-load on the aquatic Fauna: A synthesis of 17 years of biological survey on the rivers Werra and Weser

The reduction and the smoothened amplitudes of the chloride concentrations since 2000 have resulted in a gradual positive development of the aquatic fauna in the River Werra. In the salinized section of the river increasing species numbers have been determined along the salinity gradient, which shows maximum chloride concentrations of about 2500 mg/l, maximum potash concentrations at approximately 200 mg/l, and magnesia concentrations peaked at 320 mg/l. As an immediate consequence of the reduction in salt concentration the immigration of various caddis fly species into the lower River Werra was observed. The Number of taxa per sample rose from 5 to more than 30 in the lower Werra region. Changes in species-richness could be seen more frequently in river sections where chloride concentrations fluctuated around 1500 mg/l.     

Automatisierte Labormethoden zur Wasserbeschaffenheitsuntersuchung unter Anwendung der kontinuierlichen Fließanalytik

The analytical measurement technique presented consists of the ADM 300 flow stream system with two-channel operation and the AE 4 evaluation unit for four-channel operation. Selected parameters for important components of water quality are presented, such as those used in preferred combined methods in the practice of the laboratories of water and wastewater monitoring. The following components with detection limits in mg/l are concerned: ammonium 0.04, nitrite 0.07, nitrate 0.32, N_org. 0.35, o-PO₄ 0.02, total PO₄ 0.08, SiO₂ 0.08, sum of cations 0.79 mmole/l; Mn 0.02, Fe 0.34, Cl^? 15.4 and UV-absorbance 0.01 cm^?1. The detailed examination of the techniques on samples of waters has proved a statistically secured agreement of the analytical results with the results of the standard methods, with the simultaneous increase of the number of analyses by 100 … 300= and a saving of chemicals of 80= compared with the manual analysis. The device system has the interfaces required for the further data processing by means of PC. The boundary conditions for the application of this technique, especially the necessary lot sizes and laboratory organization, are referred to.     

Zur Konzentrationsabhängigkeit der Sorption von Co(II) an Titanschwamm

The sorption of Co(II) from aqueous solutions on granulated titanium dioxide was investigated in dependence on pH-value (pH = 6 … 10) and solution concentration (c_L = 10^?7 … 10^?2 mol/kg) at 83 °C. The precipitation in the solution occurred at high pH-values and solution concentrations was determined by control experiments without the adsorber. The adsorption isotherms are S-shaped. This can be interpreted as transition from chemisorption at the basic material to surface precipitation.     

Chlorination of Humic Acids and Chloroform Production

By diluting a boggy water there is produced water with a COD-Mn of 3.4 … 10.6 mg/l O₂ which is due only to humic substances. The water is mixed with 2.5 … 12.9 mg/l Cl₂ at pH-values of 5.2 … 8.5 and incubated for 24 h at 20°C. CHCl₃ concentrations of 38 … 480 μg/l were found by the subsequent gas-chromatographic determination. The production of chloroform can be calculated by means of a quadratic polynomial in dependence on COD-Mn, chlorine concentration and pH-value.     

An Estimation of the Mercury Content in the Waters of the Pomeranian Baltic-Shore-Area

In 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 (?upawa) 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.     

Vorkommen und Bewertung polyzyklischer aromatischer Kohlenwasserstoffe in einem mit kommunalen und industriellen Abwässern belasteten Fließgewässer

The river with a catchment of 5,400 km² is investigated over a length of 230 km at seven stations for the total concentration of six polycyclic aromatic hydrocarbons (PAH) and the total of three carcinogenic polycyclic substances (CPS) in the water by means of thin-layer chromatography. The maximum load occurs in the lower course downstream of large industrial wastewater introduction points with 5.1 μg/l polycyclic aromatic hydrocarbons, whereas in the upper course the maxima are at 2 … 3 μg/l polycyclic aromatic hydrocarbons for a mainly municipal pollution. The average daily load increases from 0.146 kg/d PAH and 0.048 kg/d CPS to 4.168 and 1.401 kg/d, respectively. In the flowing water there cannot be observed any self-purification concerning these substances, by an interconnected storage reservoir seston is reduced and thus also the PAC-concentrations are reduced by 50 … 60%. The PAH-concentration shows a significant positive correlation with the COD-Mn and the ammonium concentration. There is also a good agreement between the concentrations measured and the concentrations calculated from the wastewater load in the longitudinal section of the river.     

Zytotoxikologische Untersuchung von Schadstoffen und Wasserblüten mit gefrierkonserviertem Bullensperma (Spermatest)

The 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.     

Salt pollution of the middle and lower sections of the river Werra (Germany) and its impact on benthic macroinvertebrates

In two survey phases (2003 and 2008) organic, nutrient and salt contamination parameters have been investigated in the lower Werra in order to estimate the importance of these different kinds of pollution for the quality component of macroinvertebrates according to the European Water Framework Directive. The chemical and biological investigations have been carried out comparing a “reference” section without salt contamination with the salt contaminated section due to the potash mining industry from Vacha to Hannoversch Münden close to the mouth of the Werra. The results show that the drastic differences between the macroinvertebrate assemblages of the Werra upstream and downstream the salt contaminated sections are clearly caused by the salt load. The other kinds of chemical impacts are not responsible for the observed fundamental change within the composition of the benthic invertebrate assemblage. General degradation of stream morphology, indicated by macroinvertebrates, shows a good ecological status for the non-salt-contaminated part of the river and a bad status for the salt contaminated sites of the lower Werra.     

Estimate of the Eutrophication Process in the Gruža Reservoir (Serbia and Montenegro)

The Gru?a Reservoir (located at 238…269 m a. s. l., volume 64.6 · 10⁶ m³, surface 934 ha, drainage area 318 km², max. depth 31 m, mean theoretical retention time 22 months) was investigated during the years 1996 to 2001. The obtained values of trophic state parameters (9…200 μg L^?1 total phosphorus, 3…99 μg L^?1 chlorophyll‐a, and 0.5…2 m transparency) indicate that water of the Gru?a Reservoir is eutrophic according to three types of classification: Carlson, OECD, and Jones and Lee. It was noticed that values of average biomass abundance are large in the Gru?a Reservoir, and they could indicate a richer trophic state. When these indices are cited in connection with parameters of the trophic state, it is apparent that the Gru?a Reservoir can be classified as a eutrophic water on the basis of total phosphorus content of chlorophyll‐a and hypertrophic water with respect to transparency.     

Physiologie des Phenolabbaus bei Rhodococcus spec. P1 Teil 1: Beziehungen zwischen Wachstum und Phenolabbau

The Actinomycetes strain of the genus Rhodococcus having been isolated from the river Saale is able to use phenol as the sole carbon source up to concentrations of 2 g/l and metabolizes phenol via the β-ketoadipic acid path (ortho-cleavage). The synthesis of the inducable enzyme system can be inhibited by chloramphenicol. In detailed experiments in discontinuous and continuous cultures the growth rate and the yield coefficient attain their maxima of 0.256 h^?1 and 0.62, resp., at phenol concentrations of 0.5 … 0.8 g/l. At higher substrate concentrations there occurs a substrate inhibition. In the range between 20 and 40°C growth and phenol utilization are highly dependent on temperature.     

Effect of Zinc,Copper and Mercury on Channa marulius (HAMILTON)

Static bioassay acute toxicity tests of Zinc, Copper and Mercury were conducted to determine the median lethal concentrations (LC₅₀s) of a freshwater teleost Channa marulius (HAM .) The 96 h LC₅₀ and 95% confidence limits for Zn²⁺ were 25.61 (24.13 … 27.12) mg/l; 0.90 (0.80 … 1.038) mg/l; for Cu²⁺ and 0.314 (0.257 … 0.371) mg/l for Hg²⁺. However, these values decreased at 240 h of exposure and were: 21.09 (18.29 … 24.60) mg Zn²⁺/l; 0.66 (0.568 … 0.841) mg Cu²⁺/l; and 0.131 (0.103 … 0.158) mg Hg²⁺/l. The relative potency ratio of Zn/Hg, Zn/Cu and Cu/Hg suggests that fish were most sensitive to Hg, followed by Cu and Zn ions. The acute toxicities of mixtures of Zn²⁺?Cu²⁺; Zn²⁺?Hg²⁺, Cu²⁺?Hg²⁺ and Zn²⁺?Cu²⁺?Hg²⁺ up to 48 h of exposure were also investigated. The additive index and ranges for Zn²⁺?Cu²⁺ were ?0.241 (-0.577 … 0.054); 0.056 (-0.269 … 0.475) for Zn-Hg; 0.285 (-0.043 … 0.718) for Cu-Hg; and -0.542 (-1.215 … 0.005) for Zn-Cu-Hg. All the mixtures tested showed a greater than additive toxicity because index ranges overlapped zero.     

High chloride concentrations in the soil and groundwater under an oak hedge in the West of France: an indicator of evapotranspiration and water movement

Chloride is a major anion in soil water and its concentration rises essentially as a function of evapotranspiration. Compared to herbaceous vegetation, high transpiration rates are measured for isolated trees, shelterbelts or hedgerows. This article deals with the influence of a tree hedge on the soil and groundwater Cl^? concentrations and the possibility of using Cl^? as an indicator of transpiration and water movements near the tree rows. Cl^? concentrations were measured over 1 year at different depths in the unsaturated zone and in the groundwater along a transect intersecting a bottomland oak hedge. We observed a strong spatial heterogeneity of Cl^? concentrations, with very high values up to 2 g l^?1 in the unsaturated zone and 1·2 g l^?1 in the upper part of the groundwater. This contrasts with the low and homogeneous concentrations (60–70 mg l^?1) in the deeper part of the groundwater. Cl^? accumulation in the unsaturated zone at the end of the vegetation season allows us to identify the active root zone extension of trees. In winter, upslope of the tree row, downwards leaching partly renews the soil solution in the root zone, while the slow water movement under the trees or farther downslope results in Cl^? accumulation and leads to a salinization of the soil and groundwater. This salinization is of the same order as experimental conditions produce negative effects on oak seedlings. The measurement of Cl^? concentrations in the unsaturated zone under tree rows at the end of the vegetation season would indicate whether certain topographic, pedological or climatic conditions are likely to favour a strong salinization of the soil, as observed in the present study. Copyright © 2009 John Wiley & Sons, Ltd.     

Die Massenentwicklung der Geißelalge Uroglena americana (Alk.) Lemm in Trinkwassertalsperren Thüringens und ihre Bekämpfung

A mass development of Uroglena americana with cellular densities of up to 13.5 · 10⁶ and 86.10⁶ cells/l, was observed in two drinking-water reservoirs. In the first case the development remained confined to the upper 20 m, in the second case there occurred a gradual shift of the maximum to deeper zones from May to July with decreasing cellular densities down to a depth of 35 m. Laboratory experiments for the control of the algae development were performed in order to protect the drinking-water resources from potential impairments of odour and taste. Samples of the storage-reservoir water with 20.10⁶ cells/l of Uroglena were concentrated up to 1.25 … 12.5 mg/l Ca(OH)₂ (pH-values of 7.2 … 9.6) by addition of calcium hydroxide and observed for 39 h. First impairment of the cells of Uroglena is detectable at 5 mg/l Ca(OH)₂ after 15 h, an immediate effect can be observed at 7.5 mg/l Ca(OH)₂ together with increased sedimentation, also Gymnodinium and Cryptomonas having been damaged. Thereupon a successful control of Uroglena by liming up to pH-values above 8.0 is possible. The application of lime to outdoor areas was not necessary, in the final analysis, since the drinking-water quality could be secured by the optimum choice of the intake depth of raw water with a maximum of 4.10³ to 77.10³ cells/l.