Trickling filters are aerobic fixed-growth reactors that incorporate suspended media which promote the growth of biomass. The name is derived from the process itself, which involves delivery of screened waste water (or liquor) to the top of the media filter. The liquor is then allowed to trickle down through the media. Concurrently air is driven upward through the media. The biomass serves to both remove organic material and to remove ammonia by assimilation. Excess biomass drains out of the media chamber and into a secondary clarifier where it is separated and transferred to sludge disposal.
ABCO supplies both rock and plastic media solutions. Plastic media is generally the preferred option as it has fewer limitations in terms of weight and can also provide a larger surface area per volume. Rock media can provide a higher degree of nitrate removal for low hydraulic loading systems, however is less efficient as the loading increases.