
Denitrifying Bacteria and Nitrate Removal
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Can adding bacteria to polluted water speed up nitrate removal? You fill six beakers with water from an algae-rich pond. Three beakers receive doses of Nitrobacter and Nitrosomonas (bacteria that convert nitrates into nitrogen gas). The other three get nothing.
All six beakers are sealed with plastic wrap. Once a week for three weeks, you test the nitrate level in each beaker with a nitrate test kit.
The beakers with added bacteria showed a much faster drop in nitrate levels than the untreated ones.
Hypothesis
The hypothesis is that nitrate-rich water containing denitrifying bacteria will exhibit a faster rate of reduction in nitrate levels.
Method & Materials
You will measure and pour water into beakers, add denitrifying bacteria, cover the beakers with plastic wrap, and measure the nitrate levels in each beaker over the course of three weeks.
You will need 2000 milliliters of water from an algae-rich pond, a plastic container with 2 liter capacity, 15ml of Nitrobacter and Nitrosomonas bacteria, 6 beakers, a measuring cylinder, a syringe, a roll of plastic wrap, and a nitrate test kit.
Results
The experiment showed that the beakers with the denitrifying bacteria added had a faster rate of reduction in the nitrate levels. This proves that the hypothesis is true.
Why do this project?
This science project is interesting and unique because it shows how denitrifying bacteria can help reduce nitrate levels in water and save the aquatic ecosystem.
Also Consider
Variations of this experiment could include testing the levels of ammonia and nitrite in water, or comparing the effect of denitrification in water samples from different sources.
Full project details
Additional information and source material for this project are available below.Related video
These videos explain the science behind this project and demonstrate key concepts used in the experiment.
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