Waste water treatment unit, e.g. for remote home, has one or more tanks planted with reeds and containing filtering layers of granular material in different sizes

摘要

The treatment unit consists of one or more tanks (1, 2) to receive the waste water, each with a recuperation drain (5) for the filtered water in the bottom, and one or more layers (14 - 17) of a filtering material. The filtering layers are of granular materials with different grain sizes, the coarsest, having a grain size of 10 - 20 mm, being at the bottom and the finest, with grains up to 2.5 mm in size, at the top. The upper layers are planted, especially with reeds. One of the layers is of a porous material with an increased specific surface, and one is of a natural mineral material such as expanded schist marketed as Mayennite (RTM). A preferred version of the unit has two tanks (1, 2), each with a 3 sq m surface area, a distributor (19) between them, and aeration pipes (7, 11). The treated water can be drained into a pit so that it filters into the ground, or can be stored for subsequent use, e.g. for watering plants.