Trickling filter

Listing ID #3515811

The under drains system is important both as a collection unit and as a porous structure through which air can circulate. The collected liquid is passed to a settling tank where the solids are separated from the treated waste water. In practice, a portion of the liquid collected in the under drain system or the settled effluent is recycled, usually to dilute strong influent waste water and to bring the filter effluent back in contact with the biological population for further treatment.