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.     

Polarographische Bestimmung von Schwermetallen im Klärschlamm

The differential-pulse polarography (DPP) and the stripping voltametry (SV) are investigated in detail with respect to their suitability for the quantitative detection of individual traces of heavy metals in sewage sludge. The results are checked on the basis of AAS analyses and by the standard-addition method. From the hydrochloric-acid extracts of fused sludge samples down to 1 μg/l can be detected by the SV, whereas the DPP reaches a sensitivity of 100 μg/l. The following basic electrolytes are used: Zn: 2 … 3 mol/l H₃PO₄; Cu: 0.4 mol/l K₂CO₃, 0.2 mol/l Na-K-tartrate, 0.1 mol/l HCl; Ni: 1 mol/l NH₄OH, 1 mol/l NH₄Cl, 25 ml/l triethylamine; Pb and Cd: 0.1 … 0.2 mol/l HCl.     

Verfahren zur Nitrateliminierung im Gewässer

In a storage reservoir with a hypolimnic volume of 3.5 hm³ the water contains 40 mg/l nitrate. A straw bale of 60 by 20 by 1.5 m was introduced as a reactor. Hypolimnic water having been polluted with a waste product of the fatty acid synthesis (30 … 20% formic, acetic, propionic, butyric and valeric acids) were pumped through it. By the use of a total of 43.8 t fatty acid mixture from June to August an additional oxygen depletion of 14 t O₂ is achieved and 49 t NO₃^? are removed at the same time. The ammonium concentration did not increase, the NO₂^? concentration, however, rose to 12 … 13 mg/l NO₂ at times. The fatty acids were used up save 0.1 mg/l. The increase of the NO₂^? concentration, of the number of germs and of the iron, manganese and phosphorus back solution due to the controlled anaerobic conditions is the drawback of the process.     

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.     

Zum Auftreten von leichtflüchtigen Halogenkohlenwasserstoffen im Badewasser

110 samples from two swimming-pools were gas-chromatographically investigated for halogenated hydrocarbons. In spite of varying chlorine concentrations between 0.1 and 2.5 mg/l Cl₂ the bacteriological results were unobjectionable. The total of the haloforms was between 1.2 and 182 μg/l, with the average value of 90 μg/l. Besides CHCl₃, CHBrCl₂, CHBr₂Cl and CCl₃NO₂ there were observed other, still unidentified compounds in the chlorinated bathing water which clearly are successive products of disinfection, too. The water treatment by flocculation and filtration does not bring about any elimination of trihalomethanes. Of special importance is the occurrence of trichloronitromethane in concentrations of 0.13 … 1.2 μg/l, whose LC₅₀ in the Daphnia test is 189 μg/l, at a threshold concentration of 160 μg/l. To limit the pollution of water and air to a minimum, specific conditions must be adhered to in the operation of indoor swimming-pools.     

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.     

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.     

Simulation des Nitratabbaus im Grundwasser

Ten 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 k_M = 210 mg/l, v_max = 1.5 mg/l · d or k₁ = 0.005 d^?1.     

Influence of Temperature on the Toxicity of Phenol and its Chloro- and Nitro-derivatives to the Fish Notopterus notopterus (PALLAS)

There is determined the LC₅₀ for 24 … 96 h of phenol, 2,4-dinitrophenol and pentachlorophenol as sodium salt by static assay at water temperatures of 16, 23 and 36°C. In addition, the combinations of the three substances were tested in the same way. With decreasing temperature, the toxicity of the individual substances decreased by 6.5 … 22%, that of the mixtures by 10 … 87%; with rising temperature, the toxicity increased by 38 … 747% and 75 … 744%, respectively. The safety limits at 23°C lie between 0.3 μg/l for a synergistically acting mixture and 0.9 mg/l for an antagonistically acting one; for the individual substances this range is 3.5 μg/l to 0.5 mg/l.     

Zur Rolle der Stickstoffixation im Stoffhaushalt eines geschichteten Sees

In the dimict lake Arend (5.1 km², 146 hm³, 49.5 m z_max), nitrogen is production-limiting with concentrations below the detection limit during the production period. Phytoplankton achieves biomasses of up to 18 mg/l fresh matter, essential contributions being made by Aphanizomenon with 2 mg/l and Anabaena with up to 10 mg/l. Nitrogen fixation was measured by the ethine reduction technique (acetylene reduction) during periods of the occurrence of heterocystforming Cyanophyceae and achieved peak values up to 6.59 μg N² · h^?1 · l^?1 or 14.87 m^?2 · h^?1 g N₂ · m^?2 · h^?1. The rates of fixation show a safe correlation with the biomass of heterocyst-containing Cyanophyceae (r = 0.88), their development beginning at values below the N : P-ratio of 2.66.     

The Concentrations of Cadmium,Lead and Copper in Filtrated Baltic Sea Water Samples Collected at Two Seasons in 1969

Two research cruises on the Baltic Sea, in July and November of 1979, were made for investigating the Baltic Sea water for its contents of dissolved cadmium, lead and copper. Atomic absorption spectrophotometry and voltammetry were used as methods of investigation, the latter method having supplied slightly lower results. In the water layer of 0 … 50 m the cadmium concentrations were 0.03 … 0.05 μg/l and the lead concentrations were 0.1 … 0.2 μg/l, seasonal changes did not have any effect on them. The copper concentrations, on the other hand, were 0.4 … 1.2 μg/l in summer and 0.1 … 0.7 μg/l in autumn. Compared with ocean waters, the lead content is remarkably high. In anoxic deep waters of the Baltic Sea the concentrations of the three metals, especially that of cadmium, are very low (< 0.01 μg/l).     

Veränderungen der Diatomeenflora der Werra unter dem Einfluß des Salzgehaltes

Under the influence of the wastewaters of the potash industry the Werra river shows considerably varying salt contents (0.47 … 28.2 g/l Cl^?, annual means 4.4 … 11.4 g/l Cl^?) in dependence on the hydrological situation. Between 1982 and 1988 a total of 112 taxa of diatoms were observed. Of special interest is the occurrence of Stauroneis constricta (EHRENBERG) CLEVE, which is new for the river Werra. Its spreading upstream was observed. Compared with earlier findings as well as within each annual cycle there are observed clear changes in the species present and in the colonization structures in dependence on the salt content. The close relations between the salt content and the diatom communities are truly expressed by the index of halobic organisms. Diversity indices of 1.048 … 3.259 as well as values of 0.074 … 0.817 for evenness verify the imbalance of the colonization, without, however, revealing a relation to the salt content, except for variations of concentration which may be too sudden.     

Methods of Analyzing Quinones in Water and Their Application in Studying the Effects of Hydrophytes on Phenols. Part 3: Phenol Elimination under the Action of Aquatic Plants

In two test series, for which 10 and 2 … 4 g/1 wet matter of higher and lower aquatic plants from the lake Baikal and from the waters in the surroundings of Irkutsk were used, phenol solutions having concentrations of 10^?3 … 10^?5 M (1 … 5 mg/1) were applied. During the investigations the possible error clue to the presence of microorganisms was eliminated. The phenol decomposition by aquatic plants proceeds as a first-order reaction. The results of analyses are summarized in several tables and graphical representations.     

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.     

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.     

Acute toxicity of bis(tributyltin) oxide to a marine copepod

A static renewal toxicity test was conducted to evaluate the response of the copepod Acartia tonsa to bis(tributyltin) oxide (TBTO), the active compound of recently developed antifouling paints. Copepods were individually placed in test tubes containing 4 ml of 0.3, 0.5, 1.0, 1.7 or 3.0 μg l^?1 TBTO with acetone and seawater. Thirty copepods were used for each treatment and control condition and all solutions were renewed daily. The 96-h LC₅₀ was 1.0 μg l^?1 with a 95% confidence interval between 0.8 and 1.2 μg l^?1 TBTO. The 144-h EC₅₀ was 0.4 μg l^?1 TBTO which approaches concentrations recently measured in San Diego Bay. Some copepods exposed to 0.3 μg l^?1 TBTO became moribund after six days.     

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.     

Hydrobiological Investigations of the Water Quality of the Water Supply Reservoirs Husinec and Římov

The two eutrophicated reservoirs Husinec (2.6 km³, 35 ha, z_max 18 m, MQ 1.87 m^3/s) and ?ímov (34.5 hm³, 216 ha, z_max 44 m, MQ 4.14 m^3/s) show concentrations of total phosphorus of 10… 50 mg/m³ and chlorophyll contents of 7… 36 mg/m³ in the summer season. For both reservoirs a good correlation exists between the chlorophyll concentration and the density of the phytoplankton (20 · 10³… 13 · 10⁶ ind./l). With average concentrations of 10… 20 mg/m³ chlorophyll a in summer, the water can be treated for producing drinking water only at a higher expenditure. The water quality will be improved by a reduction of the phosphorus load.     

Stabilization System for Waste Water Treatment and Use. Part 1. Chemistry

The difficulties arisen in an assimilation pond, as it is called, after 17 years of operation were solved by a stabilization system for the purification of effluents and utilization for fish breeding. It consists of two basins (0.56 and 1.04 ha) and a fish pond (15.58 ha) to which water can flow from a brook by-passing the system. When the stabilization system had worked for 6 years, it was proved that in the case of the average daily intake of milk of 93,846…118,134 litres, effluents flowing out of the dairy plant amounted to 205.28…228.53 m³, on average. The BOD₅ of effluents ranged from 201.33 to 261.73 kg/d and the total solids ranged from 95.5 to 139.3 kg/d on average. The average daily outflow from the pond amounted to 394.7…1567.0 m³ of water with 4.1…23.8 kg of BOD₅ and with 29.3…112.4 kg of total solids. The average decrease of the main nutrients and extractable substances ranged from 62.8% (Ca²⁺) to 100% (NO^?3). Only the BOD₅ value at the end of the growing season in 1984 (8.4…10.3 mg/l) exceeded three times the standards for the admissible pollution of the receiving stream.     

Untersuchungen über die Beeinflussung der planktischen Photosynthese durch anorganische Metallsalze im eutrophen Alpnachersee und der mesotrophen Horwer Bucht

The effects on phytoplankton photosynthesis of inorganic metal salts HgCl₂, CuSO₄, Cd(NO₃)₂, ZnCl₂ and Pb(NO₃)₂ were studied over monthly intervals. In experiments with individual metals, phytoplankton photosynthesis was not adversely affected if the concentration increase above background levels did not exceed 10^?9 mole Hg/l, 5·10^?9 mole Cu/l, 2·10^?8 mole Cd/l, 5·10^?8 mole Zn/l and 2·10^?7 mole Pb/l, respectively. However when the concentration was increased by 5·10^?10 mole Hg/l+5·10^?9 mole Cu/l+5·10^?9 mole Cd/l+5·10^?8 mole Zn/l+5·10^?8 mole Pb/l photosynthesis was significantly reduced, due to a synergetic effect of the combined metals. The influence of phytoplankton density, pH-value concentration of calcium, dissolved organic nitrogen and allochthonous debris on heavy metal toxicity was investigated. Changes in phytoplankton composition are believed to the main reason for the seasonal variation in the toxic effects of heavy metals.