Ratio Of Bod To Ultimate Given Oxygen Demand Of Biomass Calculator

Formula Used:

\[ f = \frac{Qs \times (Qi - Q)}{O2 + (DO2 \times Qw \times XR)} \]

Sewage Discharge (Qs):

m³/s

Influent BOD (Qi):

kg/m³

Effluent BOD (Q):

kg/m³

Theoretical Oxygen Requirement (O2):

kg/s

Oxygen Demand of Biomass (DO2):

Volume of Wasted Sludge per day (Qw):

m³/s

MLSS in Returned or Wasted Sludge (XR):

kg/m³

Ratio of BOD to Ultimate BOD (f):

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1. What is the Ratio of BOD to Ultimate BOD?

The Ratio of BOD to Ultimate BOD represents the proportion of 5-day biochemical oxygen demand to the ultimate biochemical oxygen demand in wastewater treatment systems. This ratio helps in understanding the biodegradability of organic matter and the efficiency of treatment processes.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ f = \frac{Qs \times (Qi - Q)}{O2 + (DO2 \times Qw \times XR)} \]

Where:

\( Qs \) — Sewage Discharge (m³/s)
\( Qi \) — Influent BOD (kg/m³)
\( Q \) — Effluent BOD (kg/m³)
\( O2 \) — Theoretical Oxygen Requirement (kg/s)
\( DO2 \) — Oxygen Demand of Biomass
\( Qw \) — Volume of Wasted Sludge per day (m³/s)
\( XR \) — MLSS in Returned or Wasted Sludge (kg/m³)

Explanation: This formula calculates the ratio by considering the BOD removal efficiency, oxygen requirements, and biomass characteristics in the treatment system.

3. Importance of BOD Ratio Calculation

Details: Calculating the BOD ratio is crucial for assessing treatment plant performance, optimizing operational parameters, and ensuring compliance with environmental regulations for effluent quality.

4. Using the Calculator

Tips: Enter all required parameters with appropriate units. Ensure values are positive and within reasonable ranges for wastewater treatment applications.

5. Frequently Asked Questions (FAQ)

Q1: What does a high BOD ratio indicate?
A: A high ratio typically indicates efficient BOD removal and good treatment performance, showing that most biodegradable organic matter is being processed.

Q2: How does oxygen demand affect the ratio?
A: Higher oxygen demand requirements generally result in a lower ratio, indicating more oxygen is needed to treat the organic load.

Q3: What are typical values for this ratio?
A: Values vary based on treatment efficiency, but well-operated plants typically achieve ratios between 0.6-0.9, indicating good BOD removal.

Q4: How does sludge wasting affect the calculation?
A: Increased sludge wasting reduces biomass concentration, which can affect oxygen demand calculations and ultimately the BOD ratio.

Q5: Can this ratio be used for process optimization?
A: Yes, monitoring this ratio helps operators optimize aeration rates, sludge retention time, and other operational parameters for better treatment efficiency.