Question

The Food to Microorganisms ratio used in the activated sludge process is given by ___ , where \(V\) is the volume of the reactor, \(S_0\) is the influent substrate concentration, \(SRT\) is the solids retention time, \(X\) is the MLSS, and \(Q\) is the rate of inflow of sewage.

• A. \( \frac{SRT \cdot X}{Q S_0} \)
• B. \( \frac{Q S_0}{V X} \)
• C. \( \frac{S_0 \cdot X}{Q \cdot SRT} \)
• D. \( \frac{SRT \cdot S_0}{V \cdot X} \)

Hint:

When designing activated sludge systems, maintaining the correct F/M ratio ensures efficient microbial activity and wastewater treatment.

Answer 1

The Correct Option is B

The Food to Microorganisms (F/M) ratio in the activated sludge process is given by \( \frac{Q S_0}{V X} \), where: - \(Q\) is the inflow rate of sewage. - \(S_0\) is the influent substrate concentration. - \(V\) is the volume of the reactor. - \(X\) is the MLSS (Mixed Liquor Suspended Solids). This ratio helps determine the microbial growth rate and is critical for efficient treatment. A high F/M ratio can lead to a higher oxygen demand and instability in the treatment process.