Purpose:

Indicate the amount of water pollution in a specific area.

Introduction:

Oxygen is one of the essential elements for the existence of life, but life can only exist when the concentration of oxygen falls within certain limits. When measuring oxygen in aquatic environments we are actually measuring the amount of oxygen dissolved in the water; thus the name Dissolved Oxygen or DO for short. The level of DO in water depends on many physical, chemical, and biochemical activities in the sample or at the sample site. The three most important factors to consider are temperature, pressure, and salinity. The amount of oxygen a given sample can hold in solution will vary with the temperature of the sample, the pressure or altitude at which the sample is measured, and the concentration of salts dissolved in the sample.

Materials:

Extech D.O Meter

Thermometer

Flask

Procedure:

1. Disconnect sensor from meter.

2. Then turn on the thermometer

3. Slide the O2 / D.O. selector to O2

4. Press the “o” key to wall the meter.

5. Connect the senor to the meter.

6. Allow the meter to stand for five minutes until stable reading.

7. Press the O2 / cal key to display 20.

Data:

Tap Water 2.9 mg/L at 26.9C

Drinking Water 1.9 m/L at 26.9C

Conclusion:

From our experiment, we can conclude that as the temperature of a water samples was the sample. The amount of dissolved oxygen decreases, thus the percentage of saturation increases. From this, we can determine that warmer water has more oxygen, and thus, is a more productive environment. We can also determine that water that receives more sunlight has higher levels of oxygen in it.