Activated Sludge Process enables this process to be demonstrated. A pump delivers raw water contaminated with dissolved organic substances (organic matter) into the aeration tank. Since aerobic microorganisms need oxygen, the raw water is aerated in the aeration tank. The activated sludge is mixed with the raw water by stirring machines. In the secondary clarifier the activated sludge is then separated from the treated water by sedimentation. The activated sludge process is the most important biological process in water treatment. Aerobic microorganisms (activated sludge) in the aeration tank use the organic matter as a source of nutrition, biodegrading it in the process. A portion of the activated sludge is returned to the aeration tank (return sludge). The treated water is collected in a tank. Oxygen concentration, pH-value and temperature can be controlled. The following flow rates are adjustable: raw water, return sludge, internal recirculation for pre-denitrification and air.
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