1. What is MLVSS?

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

2. How Does the Calculator Work?

The calculator uses the MLVSS equation:

Where:

• \( MLSS \) — Mixed Liquor Suspended Solids (mg/L)
• \( volatile\_fraction \) — Fraction of MLSS that is volatile (0-1)

Explanation: The equation calculates the biologically active portion of the mixed liquor suspended solids.

3. Importance of MLVSS Calculation

Details: MLVSS is crucial for determining the appropriate food-to-microorganism (F/M) ratio, assessing treatment efficiency, and ensuring proper operation of activated sludge systems.

4. Using the Calculator

Tips: Enter MLSS in mg/L and volatile fraction (typically 0.7-0.8 for municipal wastewater). Both values must be valid (MLSS > 0, volatile fraction between 0-1).

5. Frequently Asked Questions (FAQ)

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

Q2: What are typical MLVSS values?
A: Typical MLVSS ranges from 1,500-4,000 mg/L in conventional activated sludge systems, depending on the process.

Q3: How is volatile fraction determined?
A: By igniting dried MLSS at 550°C and measuring the weight loss (volatile solids burn off at this temperature).

Q4: Why is MLVSS important for process control?
A: It helps determine the active biomass available for organic matter removal and nutrient conversion.

Q5: How often should MLVSS be measured?
A: Daily to weekly in most plants, depending on system stability and regulatory requirements.