Intermittently Decanted Extended Aeration (IDEA)

Specifications of IDEA System:
• Ease of Design and Construction. The biological reactors, i.e.: Demand Aeration Tanks & Intermittent Aeration Tanks consist of either square or rectangular tanks which are easy and fast to design.
• IDEA sewage treatment plants do not require equalization tank or secondary clarifier; this apparently will save plenty of area as compared with the conventional sequencing batch reactor (SBR) or circular-tank structures. Due to the above reasons, huge amount of inventory cost can also be saved.
• IDEA system is an extended aeration process which produces sludge with retention time or sludge age more than 20 days. As such, the sludge generated is well stabilized and does not require further digestion in a sludge digester.
• Due to the relatively longer sludge age, IDEA sewage treatment plants can absorb the shock loads better than any other process.
• Sludge volume index as low as 100 ml/g is typically achieved for a well maintained and operated IDEA sewage treatment plant. Low SVI means good settling sludge; this will enable IDEA sewage treatment plant to have a higher MLSS operating level without incurring wash-over of suspended solid during decanting phase. Such a low SVI value is almost impossible in the SBR system.
• The inlet flow is continuous, while the treated effluent is discharged intermittently.
• IDEA system is a cyclic process which consists of Aerate, Settle and Decant occur in 6 to 8 times a day, this enables sewage to nitrified and denitrified in many cycles and ensure the nitrogen gas liberated into the sewage has never exceeded the nitrogen solubility limit in the sewage