Located near Tilburg in the Netherlands, De Rauwbraken is a manmade recreational lake, which is popular among swimmers and divers. It was created in 1967 by sand excavation and has a total surface area of approximately 4 hectares.
The treatment was an initiative of the Aquatic Ecology Department of Wageningen University who proposed that the lake be treated by a combination of Phoslock and a flocculent due to persisting problems of cyanobacteria and high phosphorus (P) concentrations in the lake. The aim was to flocculate the algal biomass to the bottom of the lake using the flocculent and then use Phoslock to capture any orthophosphate in the water column as well as phosphorus released from decomposing algae and the sediment. Eighteen tonnes of Phoslock and two tonnes of the flocculent solution were applied
The treatment of “De Rauwbraken” had an immediate and sustained effect on the lake’s appearance and ecological status. Algae and other particles were rapidly removed from the water column, with the result that the lake was able to reopen for swimming soon after the application, while phosphate and total phosphorus concentrations have remained at very low levels since the application. This has prevented blue green algae from reappearing in large numbers, with the result that no blue green algal blooms have been recorded since the treatment. The diversity of fauna and flora in the lake are indicative of a healthy ecosystem.
1 Collins Street
Melbourne VIC 3000
Phoslock (Beijing) Ecological Engineering Technology Co. Ltd
902 T6 Ronghua South Broads
No.2, Yizhuang Economic Technological Development area
Daxing, Beijing, China