Phosphorus Uptake by Biological Slimes

Although much interest through the years has surrounded luxury uptake of phosphurus by activated sludge, critical attention has largely ignored this subject in favor of biological slimes of the type found in trickling filters. Relevant to the matter of phosphorus uptake by slimes is the question of the principal mechanism involved—physical or biochemical. A unique channel apparatus with provisions for exposure of the slime surface to UV radiation was constructed to study these questions. Results strongly suggest that initial removal of soluble phosphorus in a liquid stream, passing over a viable biological slime attached to a fixed surface, is primarily the result of a biochemical, rather than a physical adsorption, mechanism. No evidence was found that luxury uptake of phosphorus takes place by biological slimes under normal operating conditions.