1. What is Deoxygenation Constant?

Definition: The deoxygenation constant (K_D) represents the rate at which oxygen is consumed by microorganisms during the decomposition of organic matter in water.

Purpose: It's a crucial parameter in water quality modeling, particularly in calculating the Biochemical Oxygen Demand (BOD) of wastewater.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( K_D \) — Deoxygenation constant (1/day)
• \( t \) — Time period (days)
• \( L_t \) — Oxygen equivalent at time t (kg/m³)
• \( L_s \) — Organic matter at start (kg/m³)

Explanation: The formula calculates the rate constant based on the ratio of remaining oxygen demand to initial organic matter over a specific time period.

3. Importance of Deoxygenation Constant

Details: Understanding K_D helps in designing wastewater treatment systems, predicting oxygen depletion in water bodies, and assessing environmental impacts of organic pollution.

4. Using the Calculator

Tips: Enter the time period in days, oxygen equivalent (L_t), and initial organic matter (L_s). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical range for K_D?
A: For domestic sewage, K_D typically ranges from 0.1 to 0.4 per day at 20°C.

Q2: How does temperature affect K_D?
A: K_D increases with temperature, typically following the Arrhenius relationship with θ ≈ 1.047.

Q3: What's the difference between K_D and BOD rate constant?
A: K_D is the deoxygenation rate constant, while the BOD rate constant (k) includes both oxidation and nitrification effects.

Q4: How do I measure L_t and L_s?
A: These are typically measured through BOD tests - L_s is the initial BOD and L_t is the BOD remaining after time t.

Q5: What units should I use for consistent results?
A: Use consistent mass units (kg/m³ or mg/L) for both oxygen equivalent and organic matter, with time in days.