How to Calculate Aeration Tank Air Quantity?

This example in connection with our previous post,

How to calculate Aeration Tank Volume?


Total BOD to be removed (Influent) = 250 mg/l (assume) x 1400  = 350 kg/Day (we consider 1400 M3/Day Effluent Plant)

Hence O2 to be transferred =350 kg/Day

Method of Aeration = Fine Bubble Diffuser

SOTE (Standard O2 Transfer Efficiency For 300 mm disc type diffuser submergence) =20%

Hence O2 required 350/0.20 =1750 kg/day.

Assuming alpha Factor (Ratio of SOTE in clean water to effluent water)=0.8 and

Another alpha Factor (Factor for fouling of diffusers) =0.8

Oxygen requirement =2734 kg/day {Oxygen % in the atmospheric air = 23.2%}

Hence, Air Requirement =11790 kg/day {With Sp.gravity of Air at 50°C =0.8 kg/M³}

Air requirement = 14737 M³/Day = 614 M³/Hr

Allowing 5% extra, So 650 M³/Hr @ 0.5 kg/cm2 blower can be select 

further note below points too.,

one more point to be consider the Depth of aeration Tank,  suppose it is 4 metre depth select 0.5 or 0.6 kg/cm² in blower side.

Article by Sivanandan



  1. Uday Dixit says:

    Thank Sir.

  2. Shailendra says:

    Excellent . Informative,

  3. Jancy says:

    The info is very useful . For my clarification, in Air requirement of aeration tank topic

    Total BOD to be removed = 250 (assume) x 1400 = 350 kg/Day; What does 1400 denotes?
    And for more details to know can you provide me the contact mail id. since I work in STP concern I like to know more about Calculation and process details from your website.

    Thank you,

  4. Pankaj says:

    What is 1400 in this calculation

  5. P_rocks says:

    Can you Please explain these calculations in detail

  6. maithili says:

    Total BOD to be removed = 250 (assume) x 1400 = 350 kg/Day

    what is 1400?

    • T.P.Sivanandan says:

      thanks your point out – 1400 we consider as effluent qty in m3/day

      • anurag says:

        Nice Post!! Really helpful.

        Can you tell me roughly SOTE % for a tubular fine bubble (say 600 mm to 1000mm) & Disc Type Coarse Bubble(80mm, 150mm)?
        Is there any thumb rule for calculating it?
        waiting for your reply

    • R.Manojkumar says:

      Plant capacity

  7. Harpreet singh says:

    Nice information sir.thanks

  8. Harpreet singh says:

    Nice information sir.thanks but finally what is volume of aeration tanks??

  9. Chetan Nimje says:

    Sir what is 250 in this calculation

0 Trackbacks

Leave a Reply

Your email address will not be published. Required fields are marked *