Activated Sludge System and Maximum Aeration Period

Activated Sludge System
An activated sludge system is a biological wastewater treatment process that utilizes microorganisms to break down organic matter present in wastewater. The system is operated in aeration tanks where the microorganisms are introduced to the wastewater and supplied with oxygen to carry out the biological reactions.

Maximum Aeration Period
The aeration period is the duration for which the microorganisms are supplied with oxygen in the aeration tanks. The maximum aeration period for a conventional activated sludge system depends on various factors such as the type and concentration of pollutants in the wastewater, the nature of microorganisms, and the design of the aeration tanks. However, the general maximum aeration period for a conventional activated sludge system is six hours.

Reason for Maximum Aeration Period
The maximum aeration period is necessary for the system to maintain a balance between the growth and decay of microorganisms. If the aeration period is too short, the microorganisms may not have sufficient time to carry out the required biological reactions, leading to incomplete treatment of wastewater. Conversely, if the aeration period is too long, the microorganisms may overgrow and consume all available nutrients, leading to the death of microorganisms and poor treatment performance.

Conclusion
The maximum aeration period for a conventional activated sludge system is six hours, which is necessary to maintain a balance between the growth and decay of microorganisms. The actual aeration period may vary depending on the specific design and operational conditions of the system.