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 biological wastewater treatment systems.

2. How Does the Calculator Work?

The calculator uses the MLVSS formula:

Where:

• \( MLSS \) — Mixed Liquor Suspended Solids (mg/L)
• \( VSS \) — Volatile Suspended Solids (mg/L)
• \( TSS \) — Total Suspended Solids (mg/L)

Explanation: The formula calculates the volatile (organic) fraction of the mixed liquor suspended solids, which represents the active biomass in the system.

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, VSS, and TSS values in mg/L. All values must be positive, and VSS should not exceed TSS. Typical MLVSS ranges from 1,500 to 4,000 mg/L in conventional activated sludge systems.

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 is a typical VSS/TSS ratio?
A: Typically 0.7-0.8 for domestic wastewater, but can vary depending on wastewater characteristics and system operation.

Q3: How often should MLVSS be measured?
A: Daily or several times per week for process control in most activated sludge plants.

Q4: What affects MLVSS concentration?
A: Wastewater strength, sludge age, aeration, temperature, and sludge wasting rate all affect MLVSS.

Q5: What if VSS is higher than TSS?
A: This is impossible as VSS is a fraction of TSS. Check your lab measurements if you get this result.