Stepaeration Activatedsludge Process

A two-stage, step-aeration activated-sludge process (see Figure 7.21.3) shows the design procedures involved (Ramalho 1983). This example assumes that the feed stream is equally divided between the two stages and the MLVSS concentration is constant throughout the tank. The steady-state mass balances on the microorganisms yield the following equations:

Q(r + 1)X - Q(r + 0.5)X = 0.5QX = YQ(Se1 - Se2) - kdXV2

A steady-state mass balance on the microorganisms around the entire system yields the following equations:

(Q - Qw)Xe + QwXr = YQ[(Si - SJ + (Se1 - SJ] - 2kdXV

(Q - Qw)Xe + QwXr = YQ(Si - Se) - 2kdXV 7.25(24) where V1 = V2 = V (equal volumes for each stage) and

The SRT and recycling ratio (r) of the process are as follows:

Equation 7.25(25) can be generalized for an n-stage, step-aeration, activated-sludge process as follows:

whereas Equation 7.25(26) is valid for any numbers of stages.

Was this article helpful?

0 0
Trash Cash Machine

Trash Cash Machine

How recyclable trash can save the world and bank us huge profits! Get All The Support And Guidance You Need To Be A Success At Recycling! This Book Is One Of The Most Valuable Resources In The World When It Comes To How To Make Profits With Trash!

Get My Free Ebook

Post a comment