Tennessee Wastewater Operator Practice Exam

What does COD measure in wastewater?

1. The total volume of dissolved solids

2. The measure of oxygen-consuming capacity of organic matter

3. The effectiveness of filtration systems

4. The concentration of pathogens present

The correct answer is: The measure of oxygen-consuming capacity of organic matter

Chemical Oxygen Demand (COD) is an important parameter measured in wastewater management. It quantifies the amount of oxygen that would be consumed if all the organic matter in a sample were to be oxidized by a chemical oxidant. Essentially, it provides a measure of the oxygen-consuming capacity of the organic material present in wastewater. This is critical for understanding the level of pollutants that can be detrimental to aquatic life if the wastewater were to be discharged untreated. Knowing the COD levels helps operators assess the treatment processes required to effectively reduce organic load before the wastewater is released into the environment. A higher COD indicates a larger presence of organic pollutants, which may necessitate more intensive treatment options to meet regulatory discharge standards. Thus, recognizing COD as a measure of the oxygen demand due to organic content is vital for wastewater treatment operations.