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.     

Untersuchungen über den Harnstoffeintrag in das Badewasser

As investigations carried out in an immersion basin of a sauna, with rinsed-off sweat and in indoor and outdoor swimming-baths have shown, from the total of 702 ± 529 mg/urea released per bather there are released 37.06 ± 24.75 mg through the skin into water; hence a urine introduction of 30 … 35 ml per bather resulting. The urea concentration in the bathing water does not show any correlation with the NH⁺₄-concentration and the COD-Mn. Although urea-degrading bacteria are present with concentrations of up to 1 ± 10⁵ colonies/ml, there does not occur any enzymatic decomposition of urea in the bathing water. Nitrification was not detected in the bathing water, either. The use of urea as a hygienic quality criterion for bathing water is not regarded as necessary: the determination of the NH⁺₄-concentration suffices as an indicator of the pollution with faecal matter and the bound effective chlorine.     

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.     

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.     

Die gaschromatographische Bestimmung von freien flüchtigen Fettsäuren (C2 — C6) im Sickerwasser von Hausmülldeponien

After extensive experiments aimed at determining the free volatile fatty acids (C₂ to C₆) in organically highly polluted percolation water of household refuse dumping places there proved optimum a column packed with 10% Carbowax 20 M on Chromatron N-AW-DMCS after having been conditioned for five days at 270°C and subsequently covered with 10% hard wax. On short retention times the investigated isomeric column pairs are completely separated. Equally favourable results were obtained also for liquid manure and silage extracts. The detection limits lie between 10 and 20 mg/l, the relative standard deviation is 20 … 30% in the range of the lower detection limit and 2 … 3% at 200 mg/l in the upper range. In the investigation of percolation waters with concentrations between 235 and 4300 mg/l reproducibility lies at a mean relative standard deviation of 0.5 … 2.8%. The technique is well suited for routine checking.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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%.     

Efficaciousness of Certain Chemicals to Control Dracunculiasis — A Field Trial

To prevent infection with Dracunculus medinensis, a carrier host, the copepod Cyclops, has to be controlled. After preceding laboratory investigations a field trial with well water and different additions of chlorine and sodium permanganate is carried out. The exposure is performed at an ambient temperature of 25… 40 °C and in bright and dark samples (5… 11 h of sunshine/d) as well as in the well. The residual concentrations of the two chemicals are an exponential function of the time of exposure with half-times between 6 and 23 h for chlorine and 11… 30 h for sodium permanganate. The depletion of the two oxidizing agents under light is faster than in darkness. Dosage should be done in such a way that the LC_90,24h after 24 h of exposure will not be fallen below; in a specific case, this guarantees at the same time that the permissible concentrations for drinking water will not be reached 96 h after addition. For this, initial concentrations of 30 mg 1 Cl₂ or 50 mg/l KMnO_r are necessary. Under these conditions, the Cyclops population had died on the seventh day after the application of chemicals, but after seven weeks it reached the original density again. With one application of chloride or sodium permanganate a week Dracunculiasis can be completely controlled.     

DO-Process Models for Shallow Systems. Part 1: Ponds and Lakes

Model statements are presented for describing the oxygen concentration in dependence on various system quantities and five different shallow water bodies. A nonlinear model in the form of a polynomial and with parameter estimation by means of recursive regression proves suitable. It is a blackbox model in which the water temperature, the biomass of phytoplankton and zooplankton and the solar irradiation are the most important input quantities. The model applications to the five water bodies reach measures of determinateness of 0.6 … 0.74 and mean square deviations between the measured and calculated oxygen concentrations of 3 … 4 mg/l O₂. Simulations of the model output by changed input data are discussed.     

Toxicity of Phenol,Pentachlorophenol and Sodium Pentachlorophenolate to a Freshwater Teleost Lebistes reticulatus (Peters)

Lebistes reticulatus (Peters) was exposed to various concentrations of phenol, pentachlorophenol and sodium pentachlorophenolate to determine their toxicity, lethal concentrations and slope functions by a static bioassay procedure. Simultaneous controls were also run. The 94h LC₅₀ values were 47.5mg/l (42.04 … 53.68) for phenol, 0.77 mg/l (0.616 … 0.963) for sodium pentachlorophenate and 0.97 mg/l (0.866 … 1.086) for pentachlorophenol. On this basis, the rank order is sodium pentachlorophenolate-pentachlorophenol-phenol. During the treatment, fish showed an abnormal swimming reflex, excessive mucus secretion, haemorrhage near lips, abdomen and basis of fins and loss of equilibrium followed by death.     

Einsatz einer konstruierten Mischkultur zur Verwertung von Mischsubstraten mit inhibierend wirkenden Substanzen

By way of introduction the general fundamentals and kinetic setups of the competitive and non-competitive as well as substrate inhibition of cultures of microorganisms are stated. Investigated on a laboratory scale is the degradation of liquid pig slurry in a 600-1 stirring fermenter with discontinuous addition (pO₂≧=30 = saturation) of methanol as external substrate by a yeast mixed culture of Metschnikowia and Pichia membranifaceans to utilize the steam-volatile fatty acids (12 g/l) and of Acetobacter methanolicus to utilize methanol. A stable fermentation with stable residual concentrations of 235 mg/l fatty acids, 142 mg/l mH₄-N an 100 … 300 mg/l methanol for aperiod of 2400 h can be achieved.     

Effect of Complexing Agents on the Acute Toxicity of Copper to Common Guppy Lebistes reticulatus (PETERS)

The acute toxicity of copper and copper plus complexing agents to common guppy Lebistes reticulatus was studied for 96 h by a static bioassay technique. The addition of complexing agents viz. disodium salt of EDTA, citric acid, sodium thiosulphate and glycine in Cu²⁺ solutions caused a great decrease in the per-cent mortality as compared to that of Cu²⁺ test solutions alone. 10 mg/l of complexing agent was added in each copper concentration in all the test series. The 96 h LC₅₀ values and 95% confidence limits in mg/l of Cu²⁺ plus were 1.23 (0.95…1.65) for Cu²⁺ alone; 4.30 (4.04 … 4.55) for Cu²⁺ plus EDTA; 1.94 (1.69 … 2.18) for Cu²⁺ plus citric acid; 3.44 (2.96 … 3.74) for Cu²⁺ sodium thiosulphate and 2.29 (2.22 … 3.02) for Cu²⁺ plus glycine.     

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.