1. What is Reactor Volume using Wasting Rate from Return Line?

Definition: This calculator determines the required volume of a reactor in wastewater treatment systems when the concentration of solids in the effluent is low.

Purpose: It helps environmental engineers design and optimize activated sludge systems in wastewater treatment plants.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( V \) — Reactor Volume (m³)
• \( θ_c \) — Mean Cell Residence Time (days)
• \( Q_w' \) — WAS Pumping Rate from Return Line (m³/day)
• \( X_r \) — Sludge Concentration in Return Line (kg/m³)
• \( X \) — Mixed Liquor Suspended Solids (MLSS) (kg/m³)

Explanation: The formula calculates reactor volume based on the sludge wasting rate and concentration parameters.

3. Importance of Reactor Volume Calculation

Details: Proper reactor sizing ensures efficient biological treatment, proper sludge age maintenance, and compliance with effluent quality standards.

4. Using the Calculator

Tips: Enter the mean cell residence time, WAS pumping rate, sludge concentration in return line, and MLSS values. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is Mean Cell Residence Time?
A: Also called sludge age, it's the average time that microorganisms stay in the system.

Q2: What is WAS Pumping Rate?
A: Waste Activated Sludge pumping rate is the flow rate of excess sludge being removed from the system.

Q3: What is typical MLSS concentration?
A: Typically ranges between 1.5-4 kg/m³ in conventional activated sludge systems.

Q4: When is this formula applicable?
A: Specifically for cases where the concentration of solids in the effluent is negligible compared to the return sludge concentration.

Q5: How does reactor volume affect treatment?
A: Larger volumes provide more contact time for biological treatment but require more energy for mixing and aeration.