Water Desalination & Filtration Instructions
Part 1: Thermal Desalination:
- Plastic container with a sealable top, Plastic wrap and cup
- Bowl which can sit on the bottom of the plastic container
- Heat lamp
- Warm (~90F) water with 3% table salt dissolved in it
- Assemble the thermal desalination reactor as indicated in the diagram below
- Place the reactor in the sun (the heat lamp) to maximize the heating of the salt water while allowing for the sides to remain cool for condensation
- While the thermal desalination is progressing, work on the filtration task on page 2
- When complete, carefully disassemble the reactor and collect as much of the clean water as possible in your plastic cup. Be careful not to contaminate your clean water with the salt water!
- Bring the water to the measuring station for measurement of water conductivity (quality) and quantity
Part 2: Water Filtration:
- 2 L plastic bottle, cut in half
- Filtration materials (gravel, sand, cotton, coffee filter paper)
- “Contaminated” water – water w/coarse ground pepper and ground cinnamon
- Jug of water for testing, cups
Using any of the materials provided, design a water filtration system which can be used to separate the contaminants from the given contaminated water. Consider the size of the contaminants, the “size” of the water flow path through the system, and any challenges with clogging of the flow path.
You will have multiple opportunities to test your filter with contaminated water. Your filter will be judged based on how much water you can filter in a given time, and how clear your filtered water is. We will measure water clarity using a turbidimeter.
After testing your filter, throw away your filter materials in the bucket provided and rinse out your plastic container.
- Before building anything, think about how the water will flow through the materials in your filter, how it could clog, what limits flow rate and filtration effectiveness, and how that impacts how you may layer the different filter materials, or even which materials you would use
- You should pre-saturate / test your system with your clean water before using it with dirty water to test the expected flow rate you will achieve, and to make sure any filter material contaminants are washed out