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Researched by Nicole B. 1999-2000 |
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The purpose of this experiment was to determine what the effects of different amounts of phosphorous on the photosynthesis of aquatic plants.
I became interested in this idea when I started learning about the high amounts of phosphorus in water around the state due to detergents.
The information gained from this experiment will educate
people about how the phosphates that are in their detergents that run into
the streams, lakes, rivers, etc will affect the oxidation of aquatic plant
life and the food chain.
My hypothesis is that as the amount of the phosphates in the water increases the amount of oxygen given off of the elodea will decrease.
I base my hypothesis on the quote on the Internet that
ì When phosphates disperse into rivers lakes, etc, it causes a large
growth rate on algae and causes the plants to choke by lack of oxygen in
the water.
The constants in this study were:
The type of plants that I used
The amount of water
The type of water.
The amount of light each beaker gets.
The type of phosphate used (triopolyphosphate)
The manipulated variable was
(The amount of phosphates in the water.
The responding variable was
(The amount of oxygen that the elodea lets off.
To measure the responding variable I will use a funnel
and a beaker to measure the oxygen given off from the elodea plant.
|
QUANTITY |
ITEM DESCRIPTION |
| 3- | 200ml Beakers |
| 6-bunches | Elodea |
| 3- | 2L.Beakers |
| 3-small | Funnels |
| 1-small | Box of TIDE (33oz.) |
| 3- | 2L Bottles |
| 3- | 25ml. Graduated Cylinders |
| 1 | Ring Stands |
| 1 | Data Record Sheet |
1. Collect all materials.
2. Take three 200mL. beakers.
3. Put one bunch of elodea in each beaker.
4. Place each 200mL. beaker into a separate two liter
beaker.
5. Then place a funnel over each beaker.
6. Fill each two liter bottle to the rim.
7. In one bottle put 2tbls. of Tide in the water, then
in the other bottle put 4tbls. of Tide inn the water. Leave the other
bottle of water neutral.
8. Mix both of the bottles with Tide in them for exactly
30 seconds.
9. Label the bottle that is neutral with an ìAî.
10. Label the bottle with the 2tbls. of Tide in it with
a ìBî.
11. Label the bottle with the 4tbls. of Tide in it with
a ìCî.
12. Label one 2 liter bottle with an ìAî
the second bottle with a ìBî and the third bottle with a ìCî.
13. Have someone help, while they are holding the funnel
over the 200mL. beaker fill the beaker with the ìAî on it
with solution and so on with "B"î and "C". Only fill
the beakers until the spout of the funnel is fully emerged.
14. Then fill a 25mL. graduated cylinder all the way
to the top with that beakers solution.
15. Place the cylinder in the solution till fully emerged.
16. Flip the cylinder until the rim of the cylinder is
overlapping the spout of the funnel. Donít allow any air into
it.
17. Use a ring stand clamp to hold the cylinder in place.
18. Let set so soap bubbles settle and take reading.
At the end of experiment subtract first reading from final reading.
19. Measure at 48hrs. following the beginning of the
experiment. Measure in mL. how much air the elodea produced in each
solution.
20. Repeat entire experiment once more.
21. Average up data.
22. Write out results.
23. Draw conclusion.
24. Enter data into computer.
25. Graph data.
( While conducting my experiment I stumbled upon an inconvenience.
I discovered that my solution B, B1, C, and C1 were too strong and were
killing the algae. When I discovered this I made a change from 4tbls.
to 2tsp. and from 2tbls. to 1tsp.
The original purpose of this experiment was to determine the effects of different amounts of phosphorous on the photosynthesis of aquatic plants.
The results of the experiment were that as the amount of phosphates in the water increased the amount of oxygen given off of the elodea decreased. So the effects were that as the phosphates increased it caused the rapid amount of growth in the algae and caused less amounts of light to reach the plant. Also the amounts of phosphorous became too high and killed the algae. The high amounts of phosphorous also killed the elodea.
See graphs below.
My hypothesis was that as the amount of phosphorous is increased the amount of oxygen the elodea gives off would decrease.
The results indicate that this hypothesis should be accepted.
Because of the results of this experiment, I wonder if the amount of phosphates also would affect the fish in the water as much as the elodea.
If I were to conduct this project again I would compare
the effects of various detergents on the photosynthesis of aquatic plants
instead of the amount of one detergent. I would also give the
elodea a longer length of time to photosynthesize.