Technical details of the Multiclean - Multimedia filter (MF)
Removes suspended solids and part of the COD from the water
Pumps the effluent through the sand filters and activated carbon filters when the pressure drop over the sand filter is within limits. Removal of part of the COD might be required to meet the effluent COD demand.
Deep filtration and large dirt retaining capacity. Furthermore, the water is evenly divided over the full cross section of the filter by special mushroom shaped inlet diffusers. A raised filter bed results in more contact time with medium.
Equipped with several man holes for inspection and filling.
Automatic cleaning by backwashing
When the pressure drop over one of the sand filters exceeds a certain level, valves are set in such a way that the effluent of the other filters is directed in the reverse direction through that filter to flush out the accumulated suspended solids. The back wash flow is directed to the effluent buffer and filtration/sludge drying bed as to not increase the hydraulic load of the biological treatment system.
Automatic control valves
Flow and pressure adjustment valves change the output of the pump between the low feed flow and the high back wash flow. Selects between normal operation and back washing for each sand filter and between discharging water leaving the sand filter to either the activated carbon filters or the effluent sewer or the effluent buffer.