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Hello, my name is
Cristin Brickner and I am an eighth grader at James W. Parker Middle School. I
am currently taking Earth and Space Science class. My classmates are also
currently involved in Creek Connections. Creek Connections is when we test
creeks for its chemical quality. We send our results to Allegheny College in
Meadvillle. Later, we take part in a symposium.
Creek Connections got me interested in Dissolved Oxygen. Dissolved Oxygen is microscopic oxygen molecules that are mixed in the water, it is found in air space between water molecules. My question is "Is there a measurable difference between running and pooled creek water?" The reason I ask this is because when running creek water hits rocks it is exposed the air. The oxygen is mixed into the water which increases the oxygen level in the water. The oxygen will change from biological oxygen demand such as: natural resources like fallen leaves, temperature changes which takes capacity. Or human impact like eutrophication. Eutrophication is when fertilizers spill into creeks which increases plant growth. The plants will soon die, aerobic bacteria will decompose them, that will take oxygen from the stream. My literature reference was the "Creek Connections Handbook" which tells me that there is more dissolved oxygen in running creek water than there is in pooled creek water, but it does not give me a measurable difference. My hypothesis is that there is more oxygen in running creek water than there is in pooled creek water. The materials I used to conduct my analysis was the Hach Kit. Inside the Hach Kit was Dissolved Oxygen Reagents, test tubes, and Sodium Thiosulfate Standard Solution. Before my experiments, I rinsed the the test tubes and Dissolved Oxygen sample bottles with Distilled Water. Then I performed my Standard Dissolved Oxygen Tests. To do this I took six sample bottles to a creek. I took three samples of running creek water and three of pooled creek water. Then I poured Dissolved Oxygen Reagents into all six bottles. I shook them, let them settle until the bottom was colored and the top was clear. Then I shook them again. After this, I went to the lab and put a third reagent in, I shook it, but I did not wait for it to settle this time. Following that I poured the sample into a test tube, then that into a smaller sample bottle. Next, I took the Sodium Thiosulfate Standard Solution by using a titration method. I used two creeks to perform my experiment. One is found behind my school which I will refer to as Parker Run. The other can be found behind my house, it doesn’t have a name, but I’ll refer to it as Brick Road.
I got these maps from Topozone.com. This is where Parker Run is located and here is a picture of it. This is a graph of my results.
The solid black bars represent running creek water and the lightly colored in bars represent pooled creek water. The dates are shown under the two bars of which I sampled. I tested five times total. Three times I sampled at Parker Run and two at Brick Road. The bars represent the average of three samples. In each time that I tested there was more oxygen in running creek water then there was in pooled creek water. My conclusion is that "Running creek water had more Dissolved Oxygen than pooled creek water." My data are consistent with my hypothesis. I have been able to constantly show, that running creek water has more Dissolved Oxygen than pooled creek water. I hope you enjoyed reading this. |
