An above-grade blower – the only moving part in the treatment process – pushes air into the airlift, which produces robust recirculation of oxygenated water throughout the submerged media.
The oxygenated water supports the growth of useful microorganisms on the surface of the media. These attached-growth microorganisms break down the organic material in the wastewater.
Microbial growth on the media surface is sloughed off by the vigorous aeration provided by the airlift. The excess solids settle out of the media to the bottom of the tank, where they are stored for intermittent removal.
Treated effluent leaves the module through a built-in baffle into the receiving environment.