Tennessee Wastewater Operator Practice Exam

How is the organic content of water typically measured?

1. Using TSS and VSS methods

2. By determining pH and conductivity

3. Using BOD, COD, and TOC

4. Through visual inspection and smell

The correct answer is: Using BOD, COD, and TOC

The organic content of water is most effectively measured using Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), and Total Organic Carbon (TOC). Each of these methods provides insight into the level of organic materials present in the water, which is critical for assessing water quality and the impact of wastewater on the environment. BOD measures the amount of oxygen required by microorganisms to decompose organic material in a sample over a specified time, typically five days. A higher BOD indicates a higher level of organic pollution. COD is a more rapid measure that quantifies the total oxygen required to chemically oxidize both biodegradable and non-biodegradable substances in the sample, offering a broader perspective on organic content. TOC directly measures the carbon content of organic compounds in water, reflecting the contribution of organic matter to water pollution. The other methods mentioned, such as TSS and VSS, primarily focus on suspended solids rather than organic content specifically, pH and conductivity pertain more to the chemical properties of the water and do not directly measure organic compounds, while visual inspection and smell provide subjective and non-quantitative assessments, lacking the precision required for water quality analysis. Thus, utilizing BOD, COD, and TOC allows for a comprehensive evaluation of