Background
Plant based purification systems, also known as green filters, are water channels whose water surface is covered by aquatic plants, which have swimming roots. Through metabolism of the plants, organic substances which are in the waste water are degrading. By these plant based purification systems domestic waste water can be cleaned relatively well.
The green filter has been implemented in Paraguay, in a community with about 4,000 inhabitants. The project was run by the south American partner organisation Fundación Moisés Bertoni. The Global Nature Fund (GNF) as well as the Fundación Global Nature (FGN) from Spain shared their knowledge and experiences in the field of green filter systems.
Project implementation
The municipality already used a waste water system, to which 841 households were attached. But there was no intact waste water purification system to treat the domestic waste water, before running into river Salado, giving rise to eutrophication. This again led to hygienic and health problems of the residents, since they use the water from the river for drinking and for washing.