Vegetated filters or reed bed are a category of constructed wetlands, as such they display all their benefits. These are wetlands with water flowing through a planted granular substrate. We design and apply the three main categories of vegetated filters, in two treatment steps if required (for categories 1 and 2):
- Vertical vegetated filters: water generally flows from top to bottom, the advantage being no upstream settling requirement for domestic wastewater treatment. For some specific pollutant treatment, the water may flow under pressure from bottom to top;
- Horizontal vegetated filters: water flows from one side of the filter to the other, below the surface of the substrate. A vertical filter or a settling step (such as a septic tank) is required upflow to remove suspended matter.
- Combined vertical and horizontal vegetated filters (see FILTRAN® description).
In addition to the selection of plants adapted to the local climate, our expertise also lies in granular substrate selection:
- Particle size and substrate stability are critical to the proper operation of the filter;
- In accordance with our principles, we work as much as possible with locally-sourced substrates;
- The selection of a reactive substrate (see the specific product category) can provide specific treatment properties to vegetated filters.