1. What is MLVSS?

MLVSS (Mixed Liquor Volatile Suspended Solids) represents the concentration of organic solids in the activated sludge process of wastewater treatment. It's a key parameter for monitoring and controlling the biological treatment process.

2. How Does the Calculator Work?

The calculator uses the MLVSS equation:

Where:

• \( MLVSS \) — Mixed Liquor Volatile Suspended Solids (mg/L)
• \( ash\_fraction \) — Fraction of inorganic solids (dimensionless, 0-1)
• \( MLSS \) — Mixed Liquor Suspended Solids (mg/L)

Explanation: The equation calculates the volatile (organic) portion of the total suspended solids by subtracting the inorganic (ash) fraction.

3. Importance of MLVSS Calculation

Details: MLVSS is crucial for determining the active biomass concentration in activated sludge systems, which directly affects treatment efficiency and process control.

4. Using the Calculator

Tips: Enter MLSS in mg/L and ash fraction as a decimal between 0 and 1. Typical ash fractions range from 0.2 to 0.4 for municipal wastewater.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between MLSS and MLVSS?
A: MLSS includes all suspended solids, while MLVSS represents only the volatile (organic) portion that contains the active biomass.

Q2: How is ash fraction determined?
A: Ash fraction is measured by igniting dried MLSS at 550°C - the remaining mass is the ash (inorganic) fraction.

Q3: What are typical MLVSS values?
A: In activated sludge systems, MLVSS typically ranges from 1,500 to 4,000 mg/L, depending on the process.

Q4: Why is MLVSS important?
A: MLVSS helps determine food-to-microorganism (F/M) ratio, which is critical for process control and optimization.

Q5: How often should MLVSS be measured?
A: For most plants, daily measurement is recommended, though smaller plants may measure less frequently.