Otterstedter See, Germany
In Germany, Phoslock is sold under the tradename Bentophos.
The Otterstedter See is a 4.5 ha lake near the city of Bremen in Northern Germany which was treated with 11 tonnes of Phoslock/Bentophos between the 30.10.2006 and the 1.11.2006. The lake is a natural lake with a maximum depth of 11m which was formed approximately 12,000 years ago at the end of the ice age. It is a popular recreational lake for the town of Ottersberg and is surrounded on all sides by cottages built amongst trees.
Phosphorus concentrations in the sediment were measured to be 2,900 mg P / kg dry weight, of which almost 70% was determined to be available for biological processes. Removal of water from the hypolimnion for several years prior to the application had reduced phosphorus concentrations above the sediment but had been unsuccessful in preventing phosphorus release from the sediment.
The application of Phoslock/Bentophos was undertaken by Bentophos GmbH, the licensee for Germany, and was aimed at preventing continued release of phosphorus from the sediment. This objective was achieved and the results of the application are presented in the downloadable treatment report.