Entry Task:

How was your Spring Break? Share about what you did over break! Anything new and exciting?

Objective:

The students will be able to explain the desalination process.

Assessment Question #9

Explain why some Middle Eastern countries, such as the UAE use desalinization processes. Be sure to fully explain and describe the desalinization process. Discuss the benefits and concerns of this process.

WATER!

 Why is water essential to human life?

Why it is not possible for humans to drink water from the ocean?

How does fresh water differ from ocean water?

Ocean water contains about 3.5% table salt (NaCl), while fresh water has a much lower concentration of salt (about 0.05%). Since the human body has a salt concentration of about 0.9%, drinking ocean water actually dehydrates or removes water from the cells of the body. Human body cells require water to complete a number of different cellular processes. Drinking fresh water provides these cells with water to carry out the necessary functions of the cell

What percentage of the water on Earth is fresh water?

Over 75% of planet Earth is covered by water. However, about 97.5% of all of the water on Earth is ocean water, or water with a salt concentration of about 3.5%. In fact, only around 2.5% of Earth’s water is fresh water for direct human consumption. While ocean water is highly abundant, fresh drinking water sources are much scarcer than sea water.

What percentage of Earth’s fresh water is readily available in lakes, river, and streams?

Most of Earth’s fresh water is not readily available for human consumption. About 70% of this water is locked up in ice caps and would have to first be melted before yielding drinking water. Other fresh water is in the atmosphere or deep within the earth in locations not reachable with current technologies. Only 1.3% of fresh water is located in regions where relatively easy access to the water is available.

What are some common methods for purifying ocean water?

Although currently costly, ocean water can be purified or desalinated for human drinking. A number of process can remove the salt from ocean water, including ion exchanges, reverse osmosis, and boiling or freezing the ocean water. Some have even suggested that icebergs could be lassoed, towed to dry regions, and melted to supply drinking water. A more practical solution is to use small temperature gradients between different depths of ocean water to power a desalination plant. All of these methods have limitations and generally are much more expensive than using existing fresh water supplies.

What is desalination?

Desalination Game! Challenge the class to figure out the most effective

way to desalinate water and make it safe for drinking using an online simulation.

Explain that the simulation is designed to be a very challenging puzzle. They must work together to figure out how to build a machine that will desalinate water for the class. Tell students they will work in pairs for 5-10 minutes, and then collaborate with other class members.

POSTED ON GOOGLE CLASSROOM: https://educators.brainpop.com/bp-game/desalination/

Username = uasdubaiPassword = uasd1234

Have students share their strategy with the pair they teamed up with.

Did they click randomly and observe what happened, read the blurbs and reason based on the information there, experiment with various pipes, or use the help button?

Invite the pairs to talk about what strategy seemed to have been most effective.

Which pipes are needed for each connection? (Gas pipes are for transporting gas, water pipes for water, etc.)

How do you know when/where a water pump is needed? (You need a pump anytime you pull water out of a reservoir.)

Make sure students understand they need to have a green "complete" message for each of the tasks and can then press the "start" button to test out their system. They can hit "reset depths" to experiment with the optimal water flow.

Conclusion…How is water desalinated and/or purified in places where there is no easily accessible clean drinking water?

Research various methods that are being used.