In certain rural areas, collective water treatment is not an economically viable solution due to the cost of the water collection facilities (difficult terrain, distance between the houses); for various reasons, however, the traditional individual water treatment system is not highly regarded (bad installation, insufficient maintenance, …) and thus, work has been carried out to develop a high-performance and compact alternative solution for domestic waste water treatment.

This alternative system makes use of a compact sand filter installed downstream from the septic tank, the filter's performance is based on supply regulation and improvement of the waste's surface distribution.

Hydraulic laboratory studies and follow-up on a testing stand using real effluent have enabled us to develop a standardized compact system which is suitable for use in most terrains. The filter's purification performance is outstanding; at a daily supply rate of 150 l/m2, the average purification yields are over 90 % for COD, BOD, NH4, NKT

From the bacteriological point of view, bacterial contamination is also significantly reduced.

Laboratory tests are being carried out at present, with the aim of further improving purification by inducing a denitrification process enabling reduction of nitrate levels.

This system's compact overall dimensions and relatively low cost mean that it can be used not only for individual waste water treatment but also for effluent treatment for small communities (≤ 400 inhabitant equivalent).

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