Delta Life 7

André analyses water samples from monitoring wells to determine the efficiency of the reed filter. An impenetrable membrane filled with soil and planted with reeds is located below the reed filter. A windmill supplies the energy to pump up conta­ minated groundwater. Harmless chemicals such as ethylene, CO 2 and chloride enter the drains with the water. Numerous kinds of micro-organisms break down a wide range of contaminated materials in the helophyte filter. About 100 cubic metres of contaminated water remains at least a week in the treatment container. The reed filter also works in winter conditions. 22 BY ANDREA FORZONI IMAGE WELMOED JILDERDA André Cinjee uses a wind-powered reed filter to clean up groundwater. A griculture, industry and households pollute ground­ water with things like detergents, pesticides and fertilisers, putting the quality of drinking water at risk. Deltares develops natural solutions such as reed filters to clean up waste water from households and industry. Reed filters made from reeds that grow in porous soil are a proven way of cleaning up waste water. Microbial and chemical processes around the roots of the plants convert the contaminated water into clean water, gas, minerals and fertilisers. Just like swamps in a natural environment. Researcher André Conjee and his colleagues Nanne Hoekstra, Jan Gerritse and Johan van Leeuwen have developed this technology further. They are conducting practical tests in an installation in Amersfoort (NL). The innovative thing about the set-up is that it treats contaminated groundwater instead of sewage water. Another special feature is that a windmill is used to generate energy to pump up the groundwater. As a result, expensive fuel becomes unnecessary and there are no carbon emissions. This double green technology may be a solution for large cities and industrial areas. It will help local authorities, homes and businesses to prevent the spread of dangerous substances and to maintain the quality of drinking water. REEDS: A SMARTWATER TREATMENT SYSTEM TESTING GROUND