ABSTRACT
The trickling filter process is one of the oldest forms of dependable biological treatment for wastewater. Trickling filter operation involves spraying wastewater over a solid media such as rock, plastic, or redwood slats (or laths). Several calculations are useful in the operation of trickling filters: these include hydraulic loading, organic loading, and biochemical oxygen demand and suspended solids removal. The main three loading parameters for the trickling filter are hydraulic loading, organic loading, and recirculation ratio. As the wastewater trickles over the surface of the media, a growth of microorganisms (bacteria, protozoa, fungi, algae, helminths or worms, and larvae) develops. As the microorganisms use the food and oxygen, they produce more organisms, carbon dioxide, sulfates, nitrates, and other stable by-products; these materials are then discarded from the slime back into the wastewater flow and are carried out of the filter.
