摘要:

AbstractOn the basis of an analysis of literature and of own investigations, the state of metalions in natural waters is described as essential for the properties. There are investigated especially: hydrolysis, polymerization and complexation with humic substances. An analytical method for determining the degree of dispersion and the shares of free and complexed metal‐ions as well as their charge and molar mass is presente

ISSN:0323-4320    

DOI:10.1002/aheh.19840120402

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19840120403

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractChemical substances can be transformed under the influence of physical/chemical and/or biochemical active factors. By this, the ecotoxicological and hygienic‐toxicological properties and effects of the substances are changed also with respect to toxicity, late effects (carcinogenetic, mutagenic, teratogenetic ones) as well as the bio‐ and geo‐accumulation behaviour. Such transformations occur also during water treatment, and therefore also the properties and effects of the transformation products have to be taken into account for determining the limit values for pollutants in raw water for the production of drinking water. Since frequently we have incompletely known transformation products or mixtures of substances, a coefficient of hazard is suggested for the evaluation. It is the quotient of the threshold concentrations of the initial substance and of the transformation products for the different (organoleptic, toxic, carcinogenic, teratogenetic etc.) effects. For several organic substances it is demonstrated that the transformation products can be regarded less toxic compared with the initial substance. Strong oxidants, however, cause an increased danger in many

ISSN:0323-4320    

DOI:10.1002/aheh.19840120404

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractThe toxicity of Na‐pentachlorophenate toViviparus bengalensisis investigated by batch tests with daily exchange of medium in the temperature range between 19 °C (February), 27 °C (April), 32 °C (June) and 30 °C (August) at times of exposure between 12 and 96 h. In the range of higher concentrations, pronounced abnormalities in behaviour by secreting mucus and discharging eggs and embryos occur. The LC50are lowest for all times of exposure at 27 °C, whereas the times of survival with a given concentration are highest at 30 °C. From the LC50, 96h, 27°C= 66 μg/l results a safe concentration of only 47 μg/l Na‐pentachlorophenate forViviparus

ISSN:0323-4320    

DOI:10.1002/aheh.19840120405

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19840120406

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractThe measurement is carried out after addition of perchloric acid up to a concentration of 0.45 M perchloric acid, and the results are compared with those obtained in 0.16 M sodium citrate as well as with a gas‐chromatographic determination, and they show a good agreement, The detection limit is 0.002 mg/l F−, the coefficient of variation is nearly 0.01 at 0.85 mg/l F−, independently of whether a direct measurement or a measurement with a standard addition is carried out. The measurement is disturbed by aluminium(III)‐ and Iron(II

ISSN:0323-4320    

DOI:10.1002/aheh.19840120407

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractAn investigation is made on the COD/OC ratio for samples from two ponds, one brook, three rivers and four reservoirs, all samples having been taken from sampling stations with a low organic load, with 2.6… 127 mg/l COD and 0.9… 38 mg/l OC. The samples were filtrated by filtration with pore sizes of 40 or 1 μm. In the course of self‐purification, the OC concentration in rivers and reservoirs decreases to 8 mg/l, whereas ponds reached minimum values of the same size. The quotient COD/OC varies as the mean value for the individual waters between 2.55 in reservoirs and 3.92 in ponds. The overall trend of the values in the sequence of pond — river — reservoir is decreasing. The variability of the COD/OC ratios both within and between the groups results in artifinial intercepts in linear regressions of the two parameters. The distribution of the values is discussed, quotients larger than four may be associated with sulphur‐containing compounds possibly coming from t

ISSN:0323-4320    

DOI:10.1002/aheh.19840120408

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractIn four tropical water works there are carried out investigations on the floc rising occurring during the day‐hours, and especially in the hot season, in the flocculators. This phenomenon is caused by the great heating of the raw water during the day‐hours, due to which between 10.00 a. m. and 10.00 p. m. a temperature difference up to 3.7 K between the influent and the effluent of the flocculators occurs during a retention period of 3.5… 5 h within the flocculators. Even temperature differences of only 1 K result in floc rising, reducing the filter run by four to seven hours. Oversaturation of the raw water with oxygen by the photosynthetic oxygen production constitutes an additional cause. As a measure against the rising and passing‐on of flocs we recommend the aeration of the water at the raw water intake point, to prevent a thermal stratification during the day‐hours and at the same time to remove the perhaps given oxygen overs

ISSN:0323-4320    

DOI:10.1002/aheh.19840120409

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractHeteropneustes (Saccobranchus) fossilis(Pisces; Clariidae) is exposed to the biocides Chlordane, Aldrin, Metasystox, Dichlorvos, Carbofuran and Sevin for 30 d at a concentration of the 1/15 fraction of LC50;96hwith daily exchange of the medium. At intervals of 5 d the respiration rate was determined for 1 h. In addition, after the end of tests 13 haematological parameters as well as the activities of the adenosine triphosphatases and the acetylcholinesterase were determined in the liver, the kidney and the gills. During all exposures to biocides the respiration rate decreases significantly with the test time. At all exposures the blood concentrations of glucose, sodium‐ and chloride‐ions show a significant increase, whereas the cholesterin content and the clotting time decrease significantly. The ATPase activity is significantly reduced only by Aldrin and Chlordane. A significant reduction of the acetylcholinesterase activity occurs in each of the three investigated tissues only for Metasystox and Dichlorvos and in the liver in addition also for Chlordane, Aldrin and Carbofuran. Therefore, the respiration rate and haematological criteria permit a general stress indication, enzymatic activities constitute a specific indication of individual groups of biocides, so that a systematic analysis of these three indication groups will probably provide a specific resultant statement in a biomonitoring system due to the specific inhibition patt

ISSN:0323-4320    

DOI:10.1002/aheh.19840120410

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19840120411

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY