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Hildesheim, Germany

Willmitzer H.,Thuringer Fernwasserversorgung | Grosse N.,Limnosa Sachverstandigenburo | Mehling A.,Harzwasserwerke GmbH | Nienhuser A.,Bergischen Trinkwasser Verbund GmbH BTV | And 2 more authors.
GWF, Wasser - Abwasser

Advantageous effects of zooplankton grazing in establishing high water quality in lakes and reservoirs often have been documented. Zooplankton filtration, particularly by larger daphnids, distinctly reduces particle concentrations in the water column giving rise for clearwater. Consequently, water processing treatment costs are reduced. In 2009, ATT has finished a zooplankton project which related the results of microscopic zooplankton analysis and water quality data from 53 reservoirs in Germany. There is ample evidence from the results, that the potential of biofiltration can be assessed from the analysis of zooplankton community size. Accordingly, a CSI (=community size index) as a new method for the assessment of bio filtration in reservoirs was created. The CSI revealed as a valuable tool for optimizing food-web management in reservoirs. Thus, as top-down control is to be an essential tool for reservoirs water quality management beside external nutrient abatement reservoir water quality management can be improved. Source

Teicke J.,Harzwasserwerke GmbH | Baumann K.,ALNUSGbR

Dams and nature protection are usually regarded as incompatible. In the Upper Harz, however, old dam plants have produced an extremely rare flora and fauna after operating over centuries with ruthlessly changing water levels. Since hardly any practical use of these water reservoirs still takes place today, nature protection authorities are expressly demanding the continued operation with varying water levels. Source

On 31st July 2010 the UNESCO World Heritage Commission decided to add the buildings of the historic Upper Harz Water Management to the list of World Heritage Sites, supplementing the existing World Heritage Site Goslar/Rammelsberg. Thus German hydraulic structures have been recognized for the first time as world cultural heritage. This recognition also applies to 65 dams whose origins go back to the Middle Ages, and which are therefore among oldest still operating in Germany. Source

Schmukat A.,Harzwasserwerke GmbH | Schmukat A.,Federal Institute of Hydrology | Duester L.,Federal Institute of Hydrology | Goryunova E.,Federal Institute of Hydrology | And 4 more authors.
Journal of Hazardous Materials

Besides the leaching behaviour of a construction material under standardised test-specific conditions with laboratory water, for some construction materials it is advisable to test their environmental behaviour also under close to end use conditions. The envisaged end use combined with the product characteristics (e.g. mineral phases) is decisive for the choice of environmental factors that may change the release of substance that potentially cause adverse environmental effects (e.g. fertilisation or ecotoxicity). At the moment an experimental link is missing between mono-factorial standardised test systems and non standardised complex incubation experiments such as mesocosms which are closer to environmental conditions. Multi-factorial batch experiments may have the potential to close the gap. To verify this, batch experiments with copper slag were performed which is used as armour stones in hydraulic engineering. Design of experiments (DoE) was applied to evaluate the impact of pH, ionic strength, temperature and sediment content on the release of As, Cu, Mo, Ni, Pb, Sb and Zn. The study shows that release and sediment-eluent partitioning of metal(loid)s are impacted by interactions between the studied factors. Under the prevalent test conditions sediment acts as a sink enhancing most strongly the release of elements from the material. © 2015 Elsevier B.V. Source

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