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 water quality problems due to high phosphorus (P) concentrations in the lake. The aim was to flocculate the suspended solids 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 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. Due to the application of PAC (poly-aluminium-chloride) as a flocculation agent, suspended solids were rapidly removed from the water column, with the result that the lake was able to reopen for swimming soon after the application. Phosphate and total phosphorus concentrations have remained at very low levels since the application with improved diversity of fauna and flora in the lake, 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