Electrodialysis Calculator

What is Electrodialysis?

Electrodialysis is an electrochemical separation process that uses ion-exchange membranes and an electric field to remove ions from a solution. It is commonly used in water treatment, desalination, and the food industry to separate charged species from aqueous solutions.

Formula

The key formula for electrodialysis calculations is the ion removal rate:

\[ R = \frac{I}{F} \]

Where:

• \( R \) is the ion removal rate (mol/s)
• \( I \) is the total current (A)
• \( F \) is Faraday's constant (96,485 C/mol)

Calculation Steps

Let's calculate the ion removal rate and final concentration for an electrodialysis process:

1. Given:
   • Total current (\( I \)) = 10 A
   • Flow rate (\( Q \)) = 100 L/h
   • Initial concentration (\( C_i \)) = 0.1 mol/L
2. Calculate the ion removal rate: \[ R = \frac{I}{F} = \frac{10 \text{ A}}{96,485 \text{ C/mol}} \approx 1.036 \times 10^{-4} \text{ mol/s} \]
3. Calculate the concentration change: \[ \Delta C = \frac{R \times 3600}{Q} = \frac{1.036 \times 10^{-4} \text{ mol/s} \times 3600 \text{ s/h}}{100 \text{ L/h}} \approx 0.0373 \text{ mol/L} \]
4. Calculate the final concentration: \[ C_f = C_i - \Delta C = 0.1 \text{ mol/L} - 0.0373 \text{ mol/L} \approx 0.0627 \text{ mol/L} \]

Example and Visual Representation

Let's visualize the electrodialysis process:

This diagram illustrates:

• The electrodialysis cell (blue outline)
• Cathode (green) and Anode (red) compartments
• Feed solution entering the cell
• Diluate (treated water) leaving the cell
• Concentrate (removed ions) leaving the cell
• Ion movement (yellow circles) from diluate to concentrate