摘要:

AbstractShip‐based experiments around Berlin and laboratory tests were carried out in order to develop spectroscopic methods for thein‐situdetermination of chlorophylla(Chla) and chemical oxygen demand (CODcr) of surface waters. The regression analysis of spectroscopic data (reflectance (R); laser‐stimulated and conventional fluorescence (IF)) and chemical‐biological data yielded correlations of a relatively good

ISSN:0323-4320    

DOI:10.1002/aheh.19910190102

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractHighly sensitive and selective methods for the determination of trace elements in waters and solutions are made possible by the combination of flotation and spectrophotometry (flotation spectrophotometry). The basis for it are multiply charged anion complexes of the analyte, which form sparingly soluble ion association complexes with singly charged basic dye cations in aqueous solution. Intense shaking of the aqueous solution with an organic solvent (having a low dielectric constant) results in the accumulation of these ion association complexes at the interface or on the vessel walls (flotation step). After separating the ion association complexes from the liquid phases, they are dissolved and dissociated in a polar organic solvent and the absorbance of the basic dye ions is measured as a function of the concentration of the analyte. By the example of the trace determination of arsenic in natural water, the possibilities of analytical chemistry by combination of flotation steps and spectrophotometry are demonstrated. According to the arsenic content, its determination can be performed by flotation spectrophotometry with crystal violet (detection limit 50 ng/ml As), by an indirect determination of arsenic via flotation spectrophotometry of molybdenum in the dodecamolybdoarsenic acid (detection limit 1 ng/ml As) or by the combination of collector precipitation of arsenic with zirconium hydroxide followed by froth flotation and flotation spectrophotometry as the determination technique (detection limit 0.05 ng/ml As). The reproducibilities of these variants are indicated and their accuracy is checked by comparison of methods.

ISSN:0323-4320    

DOI:10.1002/aheh.19910190103

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractThe main methods of estimating the mean volume of ciliates are given: ‐ cell‐shape comparison to a simple geometrical figure, ‐ direct determination, ‐ models method.The last is more precise and its simplified variant allows us to computerize the procedure of calculation the mean cell volume

ISSN:0323-4320    

DOI:10.1002/aheh.19910190104

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractSome data based on quantitative measurements at the individual and histological levels have been compared in four different populations ofMytilus edulisfrom the Biscay coast. Each population has been divided into two groups, corresponding to animals living at high and low tide levels. Biometric measurements show evident differences between samples from these two groups at all the studied stations. This should be the result of a distinct adaptation to hydric stress. On the other hand, a positive correlation between the flesh condition (FC) index: and the mean epithelial thickness (MET) of digestive tubules has been found. So, authors conclude that both FC and MET are good populational stress indices, and the use of both parameters simultaneously can be helpful in the assessment of environmental stress.

ISSN:0323-4320    

DOI:10.1002/aheh.19910190105

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractUrea uptake by the planktonic community was studied in the central Baltic Sea in July/August 1987, in March 1988 and in August 1988. Uptake was measured with14C‐urca incubations. Uptake rates were determined in the range of 0.8 … 5.7 nmol/dm3· h urea in March and 25.6 … 48.0 nmol/dm3· h urea in August. Respired CO2was found to represent 98 to 99 = of total uptake. Light stimulated urea uptake; parallel dark incubations showing usually 4.5 to 80.0 = of the uptake in the light. These results and size fractionation studies indicated that phytoplankton was dominating urea uptake. Urea proved to be an important nitrogen source for phytoplankton during the regenerated phase of the phytoplankton suc

ISSN:0323-4320    

DOI:10.1002/aheh.19910190106

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper embodies findings of twelve month on the effect of straw‐board mill effluents on the distribution and diversity of phytoplankton of the river Dhasan. The phytoplankton of the three stretches (Reference Station A, Effluent Mixing Station B and Diluted Station C) of the river was sampled regularly every month and analysed qualitatively and quantitatively. Simultaneously some of the relevant chemical parameters of the water were also analysed. The result of the water were also analysed. The result of the plankton study showed that the plankton concentration was very low. It ranged from 166 organisms to 2240 organisms per litre only. The maximum and minimum numbers were recorded in February and June‐July respectively at all stations. Winter was found to be the most favourable season and the rainy season the most unfavourable with regard to the population density. From the samples collected from all the stations we could recognise 54 genera of chlorophyceae, 25 genera of Bacillariophyceae, 24 genera of cyanophyceae, 3 genera of Dinophyceae and 2 genera each of euglenophyceae, chrysophyceae and xanthophyceae. The percentage composition of the various groups varied with stations, but by and large chlorophyceae and bacillariophyceae dominated in all the sampling stations. The data were subjected to ‘ANOVA’ and ‘t’ tests. The results show that the observed variations in the distribution and diversity of phytoplankton among the three stations were not significant at the 5= level except in the case of Eug

ISSN:0323-4320    

DOI:10.1002/aheh.19910190107

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractThe work was undertaken to investigate the mycoflora of the river Pisa and its tributary, the river Skroda. Samples of water were collected once a month over four years (1984 … 1987) for hydrochemical analysis and studies of the fungus content. Forty‐three species of fungi were found in these rivers. The following fungi unknown in Poland were found in the Pisa river:Achlya megaspermaandRhipidium partenospo

ISSN:0323-4320    

DOI:10.1002/aheh.19910190108

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractThe water‐hygienic aspects of the possibility of a release of microorganisms modified by genetic engineering are discussed on the basis of three examples: release of large amounts of bacterial spores into a drinking water protection zone for insect control etc., biotechnological nitrate elimination under anaerobic conditions in the drinking water treatment, protection of groundwater resources when the sewage‐engineering deep‐shaft biology is applied. In future, the biotechnology with microorganisms modified by genetic engineering (GEMs) will be increasingly applied in industry (pharmacy, foodstuff production), agriculture (pest control, plant preservation) and environmental protection (drinking water treatment, wastewater treatment, disposal site systems). Therefore, the monitoring of air, wastewater and production with respect to their content of GEMs or recombined DNA is a component of production hygiene in the sense of an environmental monit

ISSN:0323-4320    

DOI:10.1002/aheh.19910190109

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractThere are investigated the variables O2, BOD5, seston, NO3‐N, NH4‐N and o‐PO4from at least five‐year series of five stations along a river section of 50 km. After exclusion of a linear trend and substraction of the individual monthly mean values from the monthly mean of many years in order to eliminate the effect of the annual variation as well as testing for normal distribution, first the correlation coefficients of the variables to the flow rate Q and the temperatures of air and water are determined, which show directional changes just in the longitudinal profile of the river. The same holds for the correlation of the variables between the measuring points. From this the model structure is derived, according to which the concentration at one measuring station can be simulated by multiple regression to Q and T at the same level as well as the concentration at the upper level. The results are discussed in detail and evaluated with respect to their inclusion in longterm management models of water quantity man

ISSN:0323-4320    

DOI:10.1002/aheh.19910190110

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY

摘要:

AbstractThe fixation of slightly soluble substances on inert carriers offers the possibility to examine the exchange of heavy metals at these phases under dynamic conditions. Investigations are presented for the exchange of Zinc under various conditions (pH, different concentrations of other cations such as Na+and Ca2+or of NTA as a chelating agent) on fixed MnO2‐hydrate, Fe(OH3), CaCO3and a natural clay‐slate. Batch‐experiments showed that all phases are able to sorb Zinc with MnO2‐hydrate as the best sorbent for this metal (highest sorption constant and capacity). Column desorption experiments demonstrate that a decrease of the pH of the aqueous phase or an addition of NTA remobilise Zinc from MnO2‐hydrate, Fe(OH)3, CaCO3and also from the clay‐slate. The same effect of releasing sorbed metal (with exception of the CaCO3‐phase) show Na+or Ca2+containing solutions. Therefore Zinc is bonded under natural conditions on the oxihydrates and the clay‐slate in a labile, ion‐exchangeable form in contrast to CaCO3, on which Zinc is sorbed probably

ISSN:0323-4320    

DOI:10.1002/aheh.19910190111

出版商:WILEY‐VCH Verlag GmbH    

年代:1991

数据来源: WILEY