1. What is Specific Substrate Utilization Rate Per Day?

Definition: The rate at which a specific substrate is utilized by microorganisms within a treatment system, expressed on a per-day basis.

Purpose: It helps wastewater treatment professionals understand the efficiency of biological treatment processes.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( U' \) — Specific substrate utilization rate (1/s)
• \( Q_s \) — Sewage discharge (m³/s)
• \( Q_i \) — Influent BOD (kg/m³)
• \( Q_o \) — Effluent BOD (kg/m³)
• \( V \) — Volume of tank (m³)
• \( X' \) — Mixed liquor suspended solids (kg/m³)

Explanation: The formula calculates how efficiently microorganisms are consuming organic matter in the wastewater treatment process.

3. Importance of This Calculation

Details: Understanding substrate utilization rates helps optimize treatment plant operations, ensuring efficient organic matter removal while maintaining healthy microbial populations.

4. Using the Calculator

Tips: Enter all required parameters with appropriate units. The calculator will compute the specific substrate utilization rate in inverse seconds (1/s).

5. Frequently Asked Questions (FAQ)

Q1: What is a typical range for this rate?
A: Typical values range from 0.001 to 0.01 1/s, depending on system design and wastewater characteristics.

Q2: How does temperature affect this rate?
A: Microbial activity (and thus utilization rate) generally increases with temperature up to optimal ranges.

Q3: What if I get a negative value?
A: Negative values suggest measurement errors, as effluent BOD shouldn't exceed influent BOD in properly functioning systems.

Q4: How can I use this value in process control?
A: Monitoring changes can indicate shifts in microbial activity or wastewater characteristics needing adjustment.

Q5: What's the relationship to F/M ratio?
A: This rate is related to the food-to-microorganism (F/M) ratio, another key process control parameter.