- The hydrodynamic study of a liquid-solid fluidized bed
- Mode of operation of a bacterial bed
- The study of influencing quantities: flow, mass and surface load of the trickling filter
Fixed microorganisms eliminate organic matter by absorption of soluble and suspended constituents. As the microorganisms grow, the film thickness increases and there is an aerobic and then anaerobic two-layer film. In this second part, the endogenous mechanisms and the gases produced lead to local detachments of the biofilm which release areas available for a new colonization. This phenomenon of detachment of the biofilm or "self-cleaning" is essentially a function of the organic and hydraulic loads applied to the filter.
The oxygen necessary for aerobic metabolism is supplied by natural draft or by forced ventilation.
The liquid collected at the outlet of the film feeds a secondary settling tank in which the sludge produced is separated from the treated water. Part of the collected liquid is frequently recycled to the head of the bacterial bed to dilute the influent and ensure sufficient wetting of the biofilm. Main biological purification process in the 1950s, trickling filters have a number of advantages over activated sludge
- less monitoring;
- significant energy savings (no air blowing);
- fairly rapid "recovery" after a toxic shock;
The driver consists of: