摘要:

AbstractSince the statements by Peters on the steam distillation had not been confirmed, concentration was carried out by steam distillation/extraction (diethyl ether) in an apparatus after Rijks et al. The final determination is performed gas‐chromatographically from the ethereal extract with addition of tetrachloroethane as internal standard and securing of results by means of coupling of GC/MS. The method yields rates of retrieval of 80 … 100% in the concentration range of 10

ISSN:0323-4320    

DOI:10.1002/aheh.19890170102

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

摘要:

AbstractThe oxygen demand of the fine sediments behind the hydroelectric dam at Altenwörth, on the Austrian Danube, was investigated using a simple Biological Oxygen Demand (BOD) method. The demand was fractionated into biological and chemical uptake and the variation with depth was studied. Chemical uptake was fast, being 90% complete within 15 minutes. Biological uptake was slower and fairly constant for some hours. The kinetics was examined and the chemical uptake found to correspond quite well with a first order rate equation

ISSN:0323-4320    

DOI:10.1002/aheh.19890170103

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

摘要:

AbstractThe unity of the structure, function and performance of an ecosystem and the importance of the biotic factors are represented by the example of the storage reservoir. Besides the morphometric relation of the trophogenic layer to the tropholytic one, the effect of the stability and mixing depth as well as of the o‐PO4content on the phytoplankton development is demonstrated. The secondary production of zooplankton is described with respect to its interaction with phytoplankton and the specific relations between the available food and the greazing pressure of predators for the structure of populations ofDaphniaare treated in particular. The practical consequences resulting from abiotic and biotic structural features for water quality are pointed ou

ISSN:0323-4320    

DOI:10.1002/aheh.19890170104

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19890170105

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

摘要:

AbstractDuring complex ecological investigations on Lake Jarun (and neighbouring interstitial underground waters) which took place in 1984 and 1985, macrozoobenthos was also studied. Its qualitative and quantitative composition in a large part depends on the degree of trophy and saprobity of the water. Specially examined were the oligochaetes and chironomids larvae, which besides having a large numerical percentage also occurred with a large number of species. In addition, the representatives of other groups of macroscopic invertebrates were also mentioned, especially those which have a special significance as indicators of a certain degree of trophy and saprobity, and which are important because of their oasis preservation in this ecosystem.

ISSN:0323-4320    

DOI:10.1002/aheh.19890170106

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

摘要:

AbstractIn 1986 a chemical spill took place from the Sandoz plant in Basel, Switzerland, into the Rhine River. Several chemicals entered the river and were transported downstream. In this paper we rank the environmental hazard of eight chemicals, Disulfoton, Dinitroorthocresol, Propetamphos, Thiometon, Parathion, Etrimphos, Metoxuron and Fenitrothion found in the German section of the Rhine River. Five attributes related to the toxicity, physio‐chemical characteristics and fate are used to rank the chemicals. The fate attributes were derived using the fate model EXWAT. Two ranking methods were used and results were compared. One method is based on the standardization of the data into attributes and aggregation into an index. The second method allows one to visually compare chemicals based on a large number of test results which might otherwise be very confusing when displayed in a table form: The Hasse diagram is an effective graphical display of data difficult to understand otherwise. Results by both ranking methods show that these chemicals can be divided into two groups, the most hazardous include Dinitroorthocresol, Propetamphos and Parathion, and the least hazardous include Disulfoton, Thiometon, Etrimphos, Metoxuron and Fenitrothio

ISSN:0323-4320    

DOI:10.1002/aheh.19890170107

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

摘要:

AbstractPhysiological and ecological aspects of the application of copper sulfate as an algicide within aquatic ecosystems are reviewed. Excessive developments of algae due to eutrophication of stagnant waters have to be controlled by preventive measures preferably. Application of algicides should be an exception. The mostly used algicide is copper sulfate because it is effective, selective, economical and undesired ecological side‐effects could not be detected. Since blue‐green algae are very copper sensitive, blooms of that species can be controlled effectively. Although toxicity to fish and invertebrates has been proved for a wide range of concentrations, they are actually not endangered by the commonly applied copper concentrations, because they show avoidance reactions and are only affected by prolonged exposition to copper. Some authors, however, showed free ions to be quickly removed from the water body. Organic compounds, water hardness and high alkalinity decrease the amounts of soluble and toxic copper specimens. Some blue‐green algae species produce strong copper‐complexing and detoxifying agents‐extracellular polypeptides and hydroxamic acids. Some chelatic agents, on the other hand, increase the algicidal effectivity of copper in alkaline waters. Also lipid‐soluble ligands increase copper toxicity in many cases. Some uncertainty in knowledge call for further research.–to determine the very right moment for copper application before algal bloom appearance to avoid oxygen depletion and fish kills‐therefore to improve forecaste of bloom development.–to define the dependence of copper toxicity on the physiological state of the algae.–to search for the effects of co‐stress (simultaneous pH‐shock) in order to restrict copper concentration to low levels and–to estimate and forecast partitioning of copper to the extracellular (chemically bound) and intracellular (taken

ISSN:0323-4320    

DOI:10.1002/aheh.19890170108

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19890170109

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

摘要:

AbstractThe denitrification of biologically purified wastewater from the fibre‐board production is investigated in the batch experiment in a laboratory reactor with and without addition of methanol (0.5 ml/l) as an additional source of carbon. Without addition of methanol, in the main only a reduction of nitrate to nitrite occurs, which accumulates. The rate of reaction is low, so that the process is not yet finished after 10 h. The addition of methanol leads to an acceleration of the reactions and to a full denitrification of the wastewater within 4

ISSN:0323-4320    

DOI:10.1002/aheh.19890170110

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

摘要:

AbstractFor a speedy solution to the problem of water resources preservation it is necessary at present to enhance the level of research aimed at establishing a system of classification of water pollutants. Control of the state of the environment must be based on wide use of achievements by different branches of scientific research. Watching the change of the biological component of the biosphere (biomonitoring) is to ascertain the response by susceptible biotic forms to environmental pollutant influence. Microorganisms are among the organismus which are most susceptible to environment influence. Test culture responses to influences from different pollutants were evaluated by building mathematical models. The principles worked out in drawing up response models could be used to develop classification systems.

ISSN:0323-4320    

DOI:10.1002/aheh.19890170111

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY