Photosynthesis

Energy in food

Energy in an ecosystem

Connely Creek study

In the first trimester the evenvironmental science class takes a few trips to Connelly creek, which is a few blocks away from the school. The students bring sampling bottles and a meter stick the measure and sample the creek. They measure width, depth, flow and collect a few samples of the water. They use ths information to calculate the velocity, Nitrates, Dissolved Oxygen (or D.O.) and Biochemical Oxygen Demand (or B.O.D.).

Calculation Protocols:

Nitrates:
1. Fill the test tube to 5mL line.

2. Add one nitrate #1 Test Tab

3. Cap the tube and mix until the tablet has disintegrated

4. Add one nitrate #2 CTA Test Tab

5. Cap the tube and mix until the tablet has disintegrated

6. Wait 5 min

DO:
1. Fill the DO bottle (round bottle with glass container) with sample water by allowing the sample water to overflow the bottle for 2-3 min. Avoid turbulence and bubbles in the sample while filling.

2. Incline the bottle slightly and inset the stopper with a quick thrust to avoid trapping air bubbles. If bubbles become trapped discard sample and repeat the test.

3. Remove the stopper and add the contents of one dissolved oxygen 1 reactant powder pillow and one dissolved oxygen 2 reactant powder pillow. Stopper the bottle carefully to avoid trapping air bubbles. If bubbles become trapped discard sample and repeat the test.

4. Shake the bottle vigorously to mix. Flocculent precipitate will form. Brownish- orange precipitate indicates oxygen is present.

5. Wait for the flocculent to settle to approx. half the bottle volume. Floc will not settle if high concentrations of chloride are present. In this case wait 4-5 min before proceeding.

6. Shake the bottle vigorously again.

7. Wait for floc to settle halfway.

8. Remove the stopper and add contents of on dissolved oxygen 3 reactant powder pillow. Stopper the bottle carefully to avoid trapping air bubbles. If bubbles become trapped discard the sample and repeat the test.

9. Shake the bottle vigorously to mix. Floc will dissolve and the sample will turn yellow if oxygen is present.

10. Fill plastic tube with prepared sample.

11. Pour the contents of the tube into a square, mixing bottle.

12. Add sodium Thiosulfate standard solution. Count each drop. Swirl the mix after each drop. Add drops until the sample becomes colorless.

BOD:
1.Take sample from the creek in a black bottle that light cannot get into.

2. Wait one week

Flow:
1. Find velocity by measuring space in creek in ft.

2. Timing it, float a leaf from the top of your space measured, to the bottom

3. Then find the depth in 5 different places going, horizontally, across the creek and then find the mean of that

4. Then find the width of the creek in 5 different places going, horizontally, across the creek and then find the mean of that