Oxygen Required in Aeration Tank Calculator

Formula Used:

\[ O_a = \frac{Q_s \times (Q_i - Q)}{f} - (1.42 \times Q_w \times X_R) \]

Sewage Discharge (Q_s):

m³/s

Influent BOD (Q_i):

kg/m³

Effluent BOD (Q):

kg/m³

Ratio of BOD to Ultimate BOD (f):

Volume of Wasted Sludge per day (Q_w):

m³/s

MLSS in Returned or Wasted Sludge (X_R):

kg/m³

Oxygen Required in Aeration Tank (O_a):

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1. What is Oxygen Required in Aeration Tank?

Oxygen Required in Aeration Tank is the amount of oxygen needed to sustain the aerobic microbial activity that breaks down organic matter in the wastewater. It is a critical parameter in designing and operating wastewater treatment plants.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ O_a = \frac{Q_s \times (Q_i - Q)}{f} - (1.42 \times Q_w \times X_R) \]

Where:

\( O_a \) — Oxygen Required in Aeration Tank (mg/day)
\( Q_s \) — Sewage Discharge (m³/s)
\( Q_i \) — Influent BOD (kg/m³)
\( Q \) — Effluent BOD (kg/m³)
\( f \) — Ratio of BOD to Ultimate BOD
\( Q_w \) — Volume of Wasted Sludge per day (m³/s)
\( X_R \) — MLSS in Returned or Wasted Sludge (kg/m³)

Explanation: The formula calculates the oxygen demand based on the organic load and accounts for oxygen consumed in sludge wastage.

3. Importance of Oxygen Calculation

Details: Accurate oxygen calculation is crucial for maintaining proper aerobic conditions in the aeration tank, ensuring efficient organic matter removal, and preventing system failure.

4. Using the Calculator

Tips: Enter all values in appropriate units. Sewage discharge and sludge volume should be in m³/s, BOD and MLSS concentrations in kg/m³. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: Why is oxygen required in aeration tanks?
A: Oxygen is required to support aerobic bacteria that break down organic pollutants in wastewater through biological oxidation.

Q2: What factors affect oxygen requirements?
A: Organic loading rate, temperature, microbial population, and sludge wastage rate are key factors affecting oxygen demand.

Q3: How is the BOD ratio determined?
A: The ratio of BOD to ultimate BOD (f) is typically determined through laboratory testing and varies based on wastewater characteristics.

Q4: What happens if oxygen supply is insufficient?
A: Insufficient oxygen leads to anaerobic conditions, poor treatment efficiency, odor problems, and potential system failure.

Q5: Can this formula be used for all types of wastewater?
A: While generally applicable, specific wastewater characteristics may require adjustments to the formula or additional factors.