Water Desalination by Electrodialysis

Additional Challenges

What Can I Do With This Simulation?

  1. Now that you have worked on optimizing the parameter settings for desalinating brackish water in a single stage, how much energy (and money) can you save by desalinating salt water through multiple stages?
    Your Mission: Design a process where you take feed water with 35 ppt salinity (like seawater) through two or more desalination stages, with a goal of no higher than 2 ppt salinity (usable for agriculture). For example, you could go from 35 ppt to 20 ppt to 2 ppt, or from 35 ppt to 25 ppt to 15 ppt to 2 ppt. How low can you get the energy cost?
  2. When engineers design processes, they actually have to consider a variety of factors which sometimes involve tradeoffs (for example, is how quickly you desalinate water more important or how much energy it takes?)
    Your Mission: Choose a "client" from the options below, and design a desalination process for them using the simulation:
    • Your client is a family living in a rural area with a well on their property. The water from the well needs to be desalinated before they can use it for drinking and household purposes. The salinity of the well water is approximately 4 ppt.
    • Your client has been pumping water from an estuary to use in their factory. Due to changes in their manufacturing process, they now need to reduce the salinity of the water before using it. The estuary water has a salinity of 1.2%, but the manufacturing process requires no higher than 0.5% salinity. The factory uses approximately 5 million liters of water per day.
    • Your client has acquired land near the ocean and a permit to operate an electrolytic desalination plant. There are farms, orchards, and small towns in the area, all of which currently buy 90% of their water. Your client's research estimates that, due to increasing water prices from current sources, they could sell up to approximately 10 million gallons of water per day, provided they can desalinate the water for under 60 cents per 100 gallons.

Simulation Applet

screenshot of simulation

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What Can I Do With This Simulation?


In this challenge, you will design a desalination process using the simulation. You will need to decide the dimensions of your cells and cell stack, the flow pressure level, and the amount of voltage to apply.

Your Mission: Design a process to desalinate brackish water with salinity 7 ppt into drinkable water (no more than 1 ppt) for as little cost per volume as you can.