Importance of Activated Sludge Process in Wastewater Treatment

What is an Activated Sludge Process?
An activated sludge process is the way of treating the industrial and sewage wastewater through activated micro-organisms that stabilize the organic matter through aerobic and a continuous flow of system.

 

The activated micro-organisms such as bacteria and protozoa degrade the organic matter of wastewater into carbon dioxide, water and other products.

 

During the entire process of activated sludge treatment, aerobic environment is maintained and this is done either by diffuse or mechanical aeration method.

 

After the reaction with micro-organism, the wastewater is passed into secondary clarifier. During the process of clarification in effluent treatment plant, the sludge gets settle down and clear effluent then is discharged for further processing.

 

Illustration Number Illustration : Activated Sludge Process

 

Activated Sludge Process
To begin the activated sludge process first of air or oxygen is passed through wastewater+microorganism. This forms the biological floc in which organic matter of sewage or other wastewater is reduced to simpler form. The healthy sludge is brown floc and if the process of activated sludge takes place in poor conditions then along with required result mucilaginous filamentous bacteria also develops. This type o f sludge is then very difficult to settle down and this also results in the sludge blanket decanting that contaminate the quality of final product.

 

The entire process can take place in different kinds of sludge treatment plants. These can be package plant, oxidation ditch, deep shaft, surface-aerated basins and lagoons.

 

Types of Micro-organisms in Activated Sludge Process
The main type of micro-organisms involved in activated sludge process are bacteria and protozoa. Also the gram negative species that includes carbon oxidizers, nitrogen oxidizers, aerobes and facultative anaerobes are used in the process.

 

The category of protozoa includes the flagellates, ciliates and amoebas.
Controlled Activated Sludge Process
It is very important that the entire activated sludge process takes place in the controlled environment for high performance. The main factors in the control process are: