Dissolved Oxygen Experiment

Measurement of Dissolved Oxygen

• The purpose of the experiment was to show how temperature affects the amount of dissolved oxygen in an aquatic sample.
• Water samples were collected at different temperatures (4°C, 25°C, and 30°C) and the dissolved oxygen was determined using the Winkler Method.
• The percent saturation of oxygen was calculated using a nomograph.
• Results indicated that as the temperature increased, the dissolved oxygen in the sample decreased.

Importance of Dissolved Oxygen

• Dissolved oxygen levels are crucial in determining the quality of an aquatic environment.
• Dissolved oxygen is necessary for the metabolic processes of organisms found in water.
• Terrestrial environments hold over 95% more oxygen than aquatic environments.
• Oxygen levels in aquatic environments are very vulnerable to even the slightest change.

Measurement of Primary Productivity

• The purpose of the experiment was to demonstrate how light intensity influences primary productivity in an aquatic sample.
• Water samples were collected and wrapped to simulate different light intensities (dark, 100% light, 65% light, 25% light, 10% light, and 2% light).
• The dissolved oxygen of the samples was determined using the Winkler Method.
• Results indicated that the greater the light, the greater the primary productivity.

Procedure and Materials

• Materials used included BOD bottles, water sample, thermometer, chemicals for the Winkler method, titration vial, syringe, starch, and a nomograph.
• Procedures involved collecting water samples, fixing and testing for dissolved oxygen, and calculating percent saturation of oxygen.

Data and Observations

• Table 1 shows the results of the dissolved oxygen measurement experiment.
• Graphs 1 and 2 display the relationships between temperature and dissolved oxygen.
• Table 2 shows the results of the primary productivity experiment.
• Graph 3 displays the relationship between light intensity and primary productivity.