Method of cleaning floating filter medium for biological filtering apparatus

摘要

A method of preparing and cleaning a floating filter medium for a biological cleaning apparatus includes the steps of forming a filter layer by placing in a treating tank a granular floating filter medium having a specific gravity of about 0.3 or less and a particle size of 1 to 15 mm. Wastewater enters the tank and flows through the filter layer. Excess sludge is separated and removed from the filter medium by discharging an amount of water from the treating tank, from below the filtered layer, equivalent to 0.5 to 1.5 times the filling amount of the filter medium in a time period of between 5 to 90 seconds.