Water and phosphorus mass balance of Lake Tegel and Schlachtensee - a modelling approach.

Management models for aquatic systems can be used to determine which measures in the watershed or in the water body have been effective and/or which one should be used in future. The newly developed management models presented in the following for Lake Tegel and Schlachtensee are empirical and lake specific. The values for the unknown factors are estimated by an iterative process using optimisation routines and sensitivity analysis methods.

Strategy and current status of combating eutrophication in two Berlin lakes for safeguarding drinking water resources.

After reduction of the external phosphorus load by phosphorus elimination plants, Lake Tegel and Schlachtensee in Berlin underwent a significant trophic improvement. The phosphorus elimination plants work by precipitation/coagulation/flocculation--sedimentation--post precipitation--filtration. The external load was reduced by one to two orders of magnitude down to 10-20 mgg PL(-1).

Long-term effects of phosphorus precipitations with alum in hypereutrophic Lake Süsser See (Germany).

Precipitation and inactivation of phosphorus (P) by the addition of aluminum (Al) is a widely applied lake restoration measure. Many studies about short-term effects are reported, but little is known about long-term effects. To reduce this lack of knowledge we investigated the German hardwater lake, Süsser See, which was treated almost annually from 1977 to 1992 with aluminum sulfate (alum).

Decision support for the selection of an appropriate in-lake measure to influence the phosphorus retention in sediments.

Many in-lake measures which aimed to influence the phosphorus retention in lake sediments have failed to improve the trophic state of the lakes. The present paper introduces a systematic approach to select an appropriate in-lake measure. Before selecting an in-lake measure the goal of the measure should be defined, the problems of the lake must be identified, and the probability of success must be estimated.