Conducting the test: A sample of water is taken from the river and covered completely. The cover is to prohibit any sunlight from entering the water and causing photosynthesis, which would produce excess oxygen. The water is left to sit for 5 days, over which time period any aerobic (oxygen-requiring) organism will be consuming available oxygen. The amount of dissolved oxygen after five days is subtracted from the calculated amount of dissolved oxygen at the time of the original testing. The difference is the amount of oxygen required by the aerobic organisms in the water (BOD).
Testing: The amount of dissolved oxygen needed by micro-organisms in a body of water to break down organic material.
Importance: Used as a gauge of the effectiveness of wastewater treatment plants, it is known as a "conventional pollutant" in the U.S. Clean Water Act.
Natural Occurrence: Almost all aquatic organisms need dissolved oxygen to survive. This dissolved oxygen is vital for the decomposers that break down organic material essential for life.
Human Impact: Humans use BOD tests to determine the amount of bacteria and micro-organisms in the river. Nitrates and Phosphates can effect the outcome of a BOD test. If phosphates and nutrients are in excess, this can cause eutrophication- possibly leading to algal blooms.
Data: Our tests revealed an average BOD of 5.7mg/L, equivalent to a Q-value of 53/100. These results indicate that the demand for dissolved oxygen is very poor in this portion of the river.
Explanation of Results: We received an average Q-value of 53/100. These results are considered medium low which is not preferred. However there are factors that may have played a role in the finding of this data. The river was significantly low, causing there to be a higher concentration of materials.
Testing: The amount of dissolved oxygen needed by micro-organisms in a body of water to break down organic material.
Importance: Used as a gauge of the effectiveness of wastewater treatment plants, it is known as a "conventional pollutant" in the U.S. Clean Water Act.
Natural Occurrence: Almost all aquatic organisms need dissolved oxygen to survive. This dissolved oxygen is vital for the decomposers that break down organic material essential for life.
Human Impact: Humans use BOD tests to determine the amount of bacteria and micro-organisms in the river. Nitrates and Phosphates can effect the outcome of a BOD test. If phosphates and nutrients are in excess, this can cause eutrophication- possibly leading to algal blooms.
Data: Our tests revealed an average BOD of 5.7mg/L, equivalent to a Q-value of 53/100. These results indicate that the demand for dissolved oxygen is very poor in this portion of the river.
Explanation of Results: We received an average Q-value of 53/100. These results are considered medium low which is not preferred. However there are factors that may have played a role in the finding of this data. The river was significantly low, causing there to be a higher concentration of materials.