摘要:

The model setups having been used so far for the mathematical description of the nitrogen and phosphorus transport are outlined in the order of the components of runoff in the drainage area: transport of nutrients in the process of runoff formation and concentration for infiltration and runoff within soil, surface runoff, transport in the receiving water. For the surface runoff the “Universal Soil Loss Equation USLE” is used frequently as the starting point for model formation, as well as the sediment impulse answer. Adsorption and desorption are taken into account by the respective isotherms. Models from agriculture are used for the representation of the nutrient balance in the soil, whereas for the transport in the receiving water especially regressions on flow and deterministic model setups on nutrient conversion are applied. In all models the empirical share is still very high, and so far the model checking has failed due to insufficient measuring d

ISSN:0323-4320    

DOI:10.1002/aheh.19830110602

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19830110603

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

Plasmids have been known for about 20 years. Meanwhile, there have been selected different species of bacteria, as Shigella, Salmonella, Gonococci and Haemophilusinfluenzae strains with a plasmid‐infected resistance. The share of resistant microorganisms has increased due to the application of chemotherapeutic agents in the human and veterinary medicine and in the flora. As can be proved, the application of liquid manure on large areas and its frequently observed introduction of wastewater — also from hospitals — contribute to the distribution of the plasmids (resistance plasmids) in the enviro

ISSN:0323-4320    

DOI:10.1002/aheh.19830110604

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

The method after Strickland and Parsons is modified for fresh water as follows: filtration on glass‐fibre paper, oxidation with K2Cr2O7in cone. H2SO4for 2 h at 130 °C, dilution to 2.5 times the volume by aqua dest., centrifuging‐off of the turbidity and extinction measurement at 445 nm against the blank value, the sample solution being balanced to the transmission of 100% (extinction = 0). Here, the following calibration line holds for the concentration C and the quantity of oxidation solution Ox: C = E1cmc · 0.162 · Ox, C in mg filter. The oxidation solution contains 4.8 g K2Cr2O7as dissolved in 20 ml aqua dest. and made up with conc. H2SO4to 11. With 5 ml of this solution one is able to determine 0.05 … 1 mg C/filter. Calibration is performed with 125 mg/l glucose solution. Comparative investigations have shown a good agreement with elementary‐analytically obtained measured values. The occurring errors have been determined mainly by sampling. In the range of very small values we have to take into account a blank value of the filter due to the adsorption of dissolved organic substances on

ISSN:0323-4320    

DOI:10.1002/aheh.19830110605

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

The Actinomycetes strain of the genusRhodococcushaving been isolated from the river Saale is able to use phenol as the sole carbon source up to concentrations of 2 g/l and metabolizes phenol via the β‐ketoadipic acid path (ortho‐cleavage). The synthesis of the inducable enzyme system can be inhibited by chloramphenicol. In detailed experiments in discontinuous and continuous cultures the growth rate and the yield coefficient attain their maxima of 0.256 h−1and 0.62, resp., at phenol concentrations of 0.5 … 0.8 g/l. At higher substrate concentrations there occurs a substrate inhibition. In the range between 20 and 40°C growth and phenol utilization are highly dependent on te

ISSN:0323-4320    

DOI:10.1002/aheh.19830110606

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractAfter extensive experiments aimed at determining the free volatile fatty acids (C2to 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 routin

ISSN:0323-4320    

DOI:10.1002/aheh.19830110607

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractThe reservoir, having a volume of 76 hm3, a surface area of 1001 ha and a maximum depth of 17 m, is divided by a dam into two parts. Half of the upper part with an area of 200 ha is densely covered by macrophytes (Elodea, Potamogeton). The three main tributaries with 2.6 m3/s on an average are highly polluted and show α‐mesosaprobic conditions. The reservoir is investigated between September and March in its longitudinal section at eight stations. The organic load and the total solids show a total decrease by 60% and 66%, respectively, and 70% of this selfpurification occurs in the upper, separated part of the reservoir. In the same way, also the total nitrogen is reduced, whereas the total phosphorus is reduced already in the upper part of the reservoir by 71%, then decreasing to 21% in the second part of the reservoir. With phosphorus, besides the biological elimination obviously also precipitation by the dissolved iron occurs, the concentration of which is reduced by 44 or 76%, resp. The bacteriological load of water improved by two to three orders of magnitu

ISSN:0323-4320    

DOI:10.1002/aheh.19830110608

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractIn the daily exchange of the medium with only 7.1 mg/l Ca2+and 0.7 mg/l Mg2+during the batch experiment the LC50,96hforCyprinus carpiois 0.063 mg/l Cu2+and 3.12 mg/l Zn2+at water temperatures of 11 to 14°C. Significant differences in mortality as referred to the LC50,12hoccur for copper only after 72 h of exposure and for zinc after 48 h of exposure. The values of LC50,96hare clearly lower for both metals in the investigations described than most data given in literature for different fish species

ISSN:0323-4320    

DOI:10.1002/aheh.19830110609

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19830110610

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19830110611

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY