Ökotechnologischer Einsatz von höheren Wasserpflanzen in stehenden und gestauten Gewässern — Möglichkeiten,Grenzen

Species of macrophytes which are suitable for the biogenic aeration of the hypolimnion by macrophytes must reach positive balances of the net primary production at a high development of populations also at low light intensities and temperatures (winter). Elodea canadensis, Juncus bulbosus and Littorella uniflora from suitable sites were exposed after holding at different water depths, and the biomass development was investigated in relation to the radiation intensity. Parallel to that, the net primary production was determined in dependence on the light intensity in the bottle experiment by air-conditioned laboratory experiments (oxygen method). Elodea canadensis has been found to be suitable for the ecotechnological application to more eutrophic waters with neutral pH, especially because of the low light compensation point of the net primary production. Colonization with Juncus bulbosus, however, seems to be possible only in the acidophilic range (pH<7), whereas Littorella uniflora is not suitable for floating vegetation covers because of the higher light compensation point for a hypolimnetic colonization and the linkage to the substrate.     

Zum Leistungsvermögen makroporöser Adsorberpolymere bei der Elimination organischer Mikroverunreinigungen

In laboratory experiments the adsorption of eleven different organic substances in water is individually tested in the range of concentration of 0.2… 5.0 mg/l on EP 60 and EP 61 (styrene-divinylbenzene, non-polar) and EP 62 and Y 59 (acrylic-acid-ester-divinylbenzene, polar). In batch experiments the elimination at 1… 2 g/l adsorber quantity was 35… 80%, strongly dissociated anionic substances as benzoic acid being adsorbed only to a low degree and weakly cationic and undissociated substances being adsorbed well. Within a homologous series adsorption increases with the molar mass until the pore diameter will become too small for the taking up of substances. Under dynamic conditions (filtration technology) an elimination of 90… 100% can be expected. As a whole, the adsorption on activated carbon was better in all cases than the adsorption on the polymers. The desorption for the regeneration of the polymers is the more difficult the better the substance contained is adsorbed. By repeated loading and regeneration only a slight influence on the adsorption and desorption of a substance was found.