1. What is BOD in Sewage?

BOD (Biochemical Oxygen Demand) is a measure of the amount of oxygen that microorganisms will consume while decomposing organic matter under aerobic conditions in sewage and wastewater.

2. How Does the Calculator Work?

The calculator uses the BOD formula:

Where:

• \( BOD \) — Biochemical Oxygen Demand (kg/m³)
• \( DO \) — Dissolved Oxygen Consumed (kg/m³)
• \( V \) — Volume of Diluted Sample (m³)
• \( Vu \) — Volume of Undiluted Sample (m³)

Explanation: This formula calculates the biochemical oxygen demand by multiplying the dissolved oxygen consumed by the ratio of diluted to undiluted sample volumes.

3. Importance of BOD Calculation

Details: BOD measurement is crucial for assessing the organic pollution level in sewage and wastewater, determining treatment efficiency, and ensuring compliance with environmental regulations.

4. Using the Calculator

Tips: Enter dissolved oxygen consumed in kg/m³, volume of diluted sample in m³, and volume of undiluted sample in m³. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical BOD range for sewage?
A: Typical BOD values for raw sewage range from 100-400 mg/L, while treated sewage should have BOD levels below 20-30 mg/L.

Q2: Why is BOD testing important?
A: BOD testing helps determine the effectiveness of wastewater treatment processes and the potential environmental impact of discharged wastewater.

Q3: How long does a BOD test take?
A: Standard BOD tests typically take 5 days (BOD₅) to complete, though some rapid methods are available.

Q4: What factors affect BOD results?
A: Temperature, pH, nutrient availability, and the presence of toxic substances can all affect BOD measurement results.

Q5: What's the difference between BOD and COD?
A: BOD measures biologically degradable organic matter, while COD (Chemical Oxygen Demand) measures both biologically degradable and non-degradable organic matter.