METHOD FOR BACK WASHING BIOLOGICAL ACTIVATED CARBON

摘要

PROBLEM TO BE SOLVED: To curtail time and the volume of water for regenerating biological activated carbon by passing back washing water into a biological activated carbon column having a biological activated carbon bed for clarifying water and removing the deposits accumulated in this bed. SOLUTION: The washing water is passed as back washing water in an upward direction from below reverse from the direction of flow at the time of clarifying the water into the biological activated carbon bed 2 packed with the granular biological activated carbon, by which the deposits accumulated in the bed 2 are washed away and are suspended as suspended matter in the water. The suspended matter floating up to the water surface of the back washing water is discharged together with the back washing water from a back washing water discharge pipe 14 disposed in the upper part of the column 1. On the other hand, the suspended matter floating in the water near the expansion boundary formed by the expansion of the bed 2 as a result of the flow of the biological activated carbon grains by the back washing water is discharged together with the back washing water from a pipe which is a discharge pipe overhanging onto this expansion boundary and is provided with holes on the pipe wall.