aktiivilietepohjainen

Aktiivilietepohjainen refers to a type of biological wastewater treatment process that utilizes a sludge mixture rich in microorganisms. This process is commonly employed in municipal and industrial wastewater treatment plants to remove organic pollutants and nutrients from wastewater. The core of the active sludge method involves cultivating a high concentration of aerobic microorganisms, primarily bacteria, in the presence of dissolved oxygen and the wastewater.

In an activated sludge system, wastewater is mixed with a recycled portion of previously settled activated sludge in an aeration tank. The microorganisms in the sludge consume the organic matter in the wastewater as their food source. Aeration is crucial as it provides the necessary oxygen for the microorganisms to thrive and efficiently break down the pollutants. After a sufficient residence time in the aeration tank, the mixed liquor, containing treated wastewater and suspended sludge, flows into a secondary clarifier.

In the clarifier, gravity separates the sludge from the treated water. The settled sludge, known as activated sludge, is a dense flocculent material containing a large population of metabolically active microbes. A significant portion of this settled sludge is then recycled back to the aeration tank to maintain a high concentration of microorganisms and inoculate the incoming wastewater. The excess sludge, or waste activated sludge, is removed from the system for further treatment, such as dewatering and disposal. The clarified effluent from the secondary clarifier is largely free of organic matter and suspended solids and can be discharged or undergo further polishing steps.