摘要:

AbstractThis report on a seminar of the Water Research Institute in Prague deals with the methodological aspects of the measurement and evaluation of data for the water quality in impoundments in the CSSR mainly with respect to: the assessment of external causes, especially of anthropogenic influences in the catchment area, on the water quality (eutrophication, humic substances, trace elements), of the multi‐purpose utilization of impoundments, the classification and development of the water quality in impoundments, the intensified utilization of impoundments as well as the influences of sediments and the effect of piscicultural measures on the water quality. The paper is subdivided into the following chapters: system of measurement network and analysis, stratification number of samples, number of the criteria to be investigated, extreme periods of discharge, multi‐purpose utilization of impoundments, eutrophication, fish sto

ISSN:0323-4320    

DOI:10.1002/aheh.19850130102

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractIn continuation of a publication on the behaviour of fluorotensides in aqueous solution there were tested four selected fluorotensides, among them a noniononic ethoxylated substance and three anion‐active substances, in two different equipment with respect to their biochemical degradability. The BOD5, the potassium permanganate consumption, the dry matter contents and the loss on ignition as well as the dehydrogenase test were used as parameters for judging the degradation behaviour. In all the four cases a high biochemical stability was found, so that they must be classified into the group C “biochemically not degradable or difficult to degrade” in agreement with the results found, according to the water pollutants cata

ISSN:0323-4320    

DOI:10.1002/aheh.19850130103

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractThe carbon‐dioxide assimilation ofFontinalis antipyreticais inhibited by 100 mg/1Zn2+or Pb2+, without a lethal effect being caused. With increasing time of exposure from one to six days the threshold value of toxicity is lowered and at the same time the net assimilation is reduced within the range of concentration of 0.1 mg/1. In the ecological optimum of the environmental conditions the toxicity is weaker than under other unfavourable environmental conditions at the same time. Therefore, the photoecologically optimum illumination of 1200 lx is an effective bioprotector against phytotoxic lead ion concentrations, so that at 1200 lx also at a comparatively high load a positive photosynthesis balance can be maintained. In the dark, in the first hour after the application of the lead ions dissimilation is a function of concentration, subsequently the respiration differences decrease very much in the range between 0 and 100 mg/1 lead(II)‐ions. Stimulating effects could be demonstrated only by 0.01 mg/1 Pb2+and only for the carbondioxide assimilat

ISSN:0323-4320    

DOI:10.1002/aheh.19850130104

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractSamples taken from the influent and effluent of a biological wastewater treatment plant were immediately analysed and investigated at different intervals within four weeks after sampling. They were stored in the dark at 277 and 293 K and at pH 2 and pH 12 each. None of the measures resulted in a correct stabilization or preservation of the samples: orthophosphate cannot be stabilized by any measure, the total phosphate needs not be stabilized, the COD gives values which are still useful only at pH 2 and 277 K, TOC and DOC do not show useful results with none of the applied techniques, equally insufficient are the results for ammonium‐ and nitrate‐ions. In addition, differences occur in the behaviour of the samples taken from the influent and effluent. In agreement with the results published in the literature, the chemical analysis has to be carried out within 6 h after sampl

ISSN:0323-4320    

DOI:10.1002/aheh.19850130105

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractToday only 35% of the catchment area are covered by forests after deforestation, as compared with the original 70%. In connection with that, the concentration of humic matter has decreased from the original 8 mg/1 to 4 mg/1. The analysis of these changes is facilitated by the linear regressions of a high significance which exist between the COD‐Mn and humic acid concentration and the colour. Parallel to deforestation, also the nitrate concentration increased, which, however, can be explained by higher nitrogen concentrations in precipitatio

ISSN:0323-4320    

DOI:10.1002/aheh.19850130106

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractThe LC50for 12… 96 h of a distillery waste water were determined forLebistes reticulatus, Lymnaea luteola, Lymnaea acuminataandViviparus bengalensisin the batch experiment with daily exchange of the medium. The sensitivity of the species increases in the given sequence with values of the LC50,96 hof 10.77 to 3.72 % proportion of wastewater in the medium. Compared with this, with values of the LC50,48 hof 14.06… 15.71 % after 48 h of exposure there is no significant difference in sensitivity, whereas after exposure for 12 and 24 h the sensitivity grows in the following order:V. bengalensis, L. acuminata, L. luteola, Lebistes reticulatus. Toxicity is obviously primarily determined by the sulphides; with increasing time of exposure also the suspended matter and other factors act toxica

ISSN:0323-4320    

DOI:10.1002/aheh.19850130107

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractA model is described for the relation between water quantity and water quality in the aquifer with the diffuse substance input by the gravitation water being taken into account. The model is based on a partial differential equation of the second order for a flow pipe. For constant transport parameters, a sink of the kinetics of the first order and a time‐dependent source term an exact analytical solution is presented and explained by a model. At a diffuse substance input, the dispersion has only a slight influence on the transport of substances contained in water. Potential applications of these solutions to different problems are mentione

ISSN:0323-4320    

DOI:10.1002/aheh.19850130108

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractFor a correct determination of the activated sludge activity with the aid of TTC an optimum TTC concentration is required not only in the solution, but also as related to the biomass. Since TTC has toxic effects on bacteria, the selection of the optimum TTC concentration is connected with problems: in the suboptimal range the TTC concentration as referred to the existing bioactivity is too low, in the supraoptimal range the toxic effect does not permit any correct determination of activity. A generally optimum range cannot be stated due to the very different activities and sensitivities of the present bacterial populations. Therefore, the application of the TTC methods requires the simultaneous parallel application of different TTC concentrations and the determination of the activity in the plateau range of the relation between the TTC concentration and the formazan concentration formed.

ISSN:0323-4320    

DOI:10.1002/aheh.19850130109

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19850130110

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY

摘要:

AbstractIn the process of the biological treatment of sewage, the multicomponent system of the substrate is converted by an association of microorganisms. The composition of species of microorganisms in the system depends on the substrate available and on the conversion of substrate. For this, a mathematical model is presented, which describes the change of the composition of species according to the rate of growth of the individual species on the basis of load (substrate available/biomass). The diversity of the biological system increases with decreasing load. The model is tested by practical examples.

ISSN:0323-4320    

DOI:10.1002/aheh.19850130111

出版商:WILEY‐VCH Verlag GmbH    

年代:1985

数据来源: WILEY