Science Buddies: "Ask an Expert"

Hi, I'm a 10th grader at Carroll High School and for my science fair project I plan to build a packed-column air stripper to remove ammonia from water. I'm thinking that I'll add 1ppm of ammonia to distilled water, and then run it through the air stripper. What concentration of ammonia should I use, and where could i buy it? I am planning to use ammonia test strips to measure the 'purified' water's ammonia content.
Thanks Everybody, Dan

Hi Dan,

Great idea! Ammonia is a pretty bad pollutant, very toxic to aquatic critters, and can come from a lot of different sources both natural and manmade.

I checked the EPA criteria for ammonia as a pollutant in freshwater ponds and rivers-- http://www.google.com/url?sa=t&rct=j&q= ... XY&cad=rja

The limit for total ammonia nitrogen over a 30 day period was 1.9 ppm (mg/L) in 2013. Are your ammonia test strips sensitive enough to measure that low of concentration?

Since the target level is 1.9 ppm or less, you would want to spike the water with ammonia to a higher level—maybe 20 or even 50 ppm if your stripper can handle that much ammonia. All chemistry labs have ammonium hydroxide solutions of various molarities so check with your school chem department. Alternatively you can buy cleaning solutions containing 5-10% ammonia. Just make sure they contain ONLY ammonia and not detergent or other compounds.

Good luck!

Sybee