Water Pollution and Control: Activated Sludge Treatment

 Secondary Methods:

Activated Sludge Treatment

The activated sludge process (ASP) is a wastewater treatment method that uses aeration tanks to mix oxygen with sewage to break down organic contaminants. The process involves several steps, including aeration, settling, and sludge treatment. 

Steps 

1. Aeration

Air or oxygen is blown into the sewage to break down solids and encourage microbial growth

Diffusers or mechanical aerators provide oxygen to the aeration tanks

 

2. Settling

The wastewater-microorganism mixture flows into settling tanks, also known as clarifiers

The activated sludge particles settle at the bottom, leaving clarified water at the top

 

3. Sludge treatment

A portion of the settled sludge is recycled back into the aeration tank

The excess sludge is removed and treated before disposal Considerations

 

Wastewater characteristics: The quality and quantity of wastewater being treated 

Environmental conditions: The temperature and presence of toxic substances 

Oxygen transfer requirements: The amount of oxygen needed to foster microbial activity 

Sludge treatment requirements: How to minimize the environmental impact of the sludge 



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