1. What is the BOD Mass Formula?

The BOD (Biochemical Oxygen Demand) mass formula calculates the daily mass of organic matter in wastewater based on concentration and flow rate. This is important for wastewater treatment plant design and operation.

2. How Does the Calculator Work?

The calculator uses the BOD mass formula:

Where:

• \( BOD \) — Biochemical Oxygen Demand concentration (mg/L)
• \( Flow \) — Wastewater flow rate (L/day)
• \( 10^{-6} \) — Conversion factor from mg to kg

Explanation: The formula converts the concentration (mg/L) to total mass (kg/day) by multiplying by flow rate and applying a unit conversion factor.

3. Importance of BOD Mass Calculation

Details: Calculating BOD mass loading is essential for sizing treatment systems, determining treatment efficiency, and meeting regulatory discharge limits.

4. Using the Calculator

Tips: Enter BOD concentration in mg/L and flow rate in liters per day. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is BOD important in wastewater treatment?
A: BOD measures the amount of oxygen required by microorganisms to break down organic matter, indicating the pollution strength of wastewater.

Q2: What are typical BOD values for different wastewaters?
A: Domestic sewage: 100-300 mg/L, food processing: 500-5000 mg/L, industrial: varies widely by industry.

Q3: How does flow rate affect BOD mass loading?
A: Higher flow rates with the same BOD concentration result in proportionally higher mass loading to the treatment system.

Q4: What's the difference between BOD and COD?
A: BOD measures biodegradable organics, while COD (Chemical Oxygen Demand) measures all oxidizable matter including non-biodegradable organics.

Q5: How is this calculation used in treatment plant design?
A: BOD mass loading determines the required capacity of biological treatment units like activated sludge systems or trickling filters.