Retention Time given Volume of Flocculation Basin Calculator

Retention Time Formula:

\[ T = \frac{V \times T_{m/d}}{Q_e} \]

Volume of Tank:

m³

Time in Min Per Day:

min/day

Flow Rate of Secondary Effluent:

m³/s

Tolerance:

Retention Time (seconds):

1. What is Retention Time in Flocculation Basin?

Definition: Retention time refers to the average duration that water remains in the flocculation basin during the treatment process.

Purpose: It helps ensure proper mixing and contact time for floc formation in water treatment plants.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ T = \frac{V \times T_{m/d}}{Q_e} \]

Where:

\( T \) — Retention time (seconds)
\( V \) — Volume of tank (m³)
\( T_{m/d} \) — Time in minutes per day (min/day)
\( Q_e \) — Flow rate of secondary effluent (m³/s)

Explanation: The volume multiplied by time factor gives the total capacity-time product, which when divided by flow rate gives the retention time.

3. Importance of Retention Time Calculation

Details: Proper retention time ensures effective flocculation, which is critical for particle removal in water treatment processes.

4. Using the Calculator

Tips: Enter the volume of tank in m³, time factor in min/day, flow rate in m³/s, and tolerance percentage (default ±5%). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical retention time for flocculation?
A: Typically 20-45 minutes, but depends on water quality and treatment objectives.

Q2: Why include a tolerance percentage?
A: The tolerance accounts for variations in flow rates and operational conditions (±5% is common).

Q3: How does flow rate affect retention time?
A: Higher flow rates decrease retention time, potentially reducing treatment effectiveness.

Q4: What units should I use for the inputs?
A: Use m³ for volume, min/day for time factor, and m³/s for flow rate.

Q5: How do I convert between different time units?
A: 1 day = 1440 minutes; 1 hour = 60 minutes; 1 second = 1/60 minutes.