Science Buddies: "Ask an Expert"

My science project is beased on Earth science. I am required to do a project and my tittle is Can the sun clean salt water. Based on my research i found out that it cant because the sun will evoporate the water and will leave the salt behind. I beleave that my research is correct because the sun evaporates water. What i need to know is if this is true or not. Thank you for reading this.

Hi! That's a great question, and very important to humankind since water is one of our basic (important) requirements.

Can you define what you mean by "clean salt water" ?

If you mean removing the salts from seawater, than you are correct - sunlight does not remove the salt from seawater, and it will even concentrate it by evaporating some of the water away. Have you considered what would happen if you collected the (pure) water that evaporates off? Can you trap this water vapor somehow?

What do you plan to do as your project? You might consider something like distilling a liquid - where you use a heat source such as a flame instead of the sun. Maybe you could modify this to ake an apparatus to allow the use of the sun as well.

http://www.sciencebuddies.com/science-f ... M&from=TSW

Dear Kjustman,

Sunmoonstars made an excellent point about defining what you mean by cleaning the water. The following link describes an experiment by which salt can be removed from water, but note that it does not only entail leaving a bucket of water in the sun. In that case, the water would evaporate and be lost to the atmosphere. If you use the following mechanism or the distillation mechanism in the link that Sunmoonstars posted for you, the "clean" distilled water should not be lost.

http://www.education.com/activity/artic ... er_middle/

Hope this helps!
Michelle

Thanks for your answer. it really helped me!!!!