Biosand filters are used for purification of wastewater. Wastewater is pre-treated in precipitation tanks and then pumped to biosand filters. In biosand filters, wastewater is treated by being drained through filter material and naturally occurred microorganisms.
Biological sand filters consist of: Precipitation tank, pump part, Ø40 mm. manifold, drain pipe, outlet well, membrane 0.5 mm. thick and Ø110 mm. membrane bushing.
Wastewater can after purification be led to streams, ditches, drainages, etc.
Tunetanken biosand filters meet the requirements of SOP (increased requirement for reduction of organic material as well as nitrification and reduction of phosphorous), SO (increased requirement for reduction of organic material), OP (reduction of organic material and reduction of phosphorous) and O (reduction of organic material) purification classes.