Massachusetts Wastewater Practice Exam

The main purpose of a BOD (Biochemical Oxygen Demand) analysis in wastewater treatment is to determine the amount of organic material present in the water. BOD measures the amount of oxygen that microorganisms will consume while decomposing organic matter under aerobic conditions over a specific period, usually five days at 20°C.

This measurement is critical because it serves as an indicator of the wastewater's organic pollution level. A high BOD implies a higher concentration of biodegradable organic material, which can lead to oxygen depletion in receiving water bodies. This can harm aquatic life, hence monitoring BOD is essential for assessing the effectiveness of wastewater treatment processes and ensuring compliance with environmental regulations.

The other options focus on different aspects of water quality monitoring. Measuring pH levels is a separate analysis important for evaluating acidity or alkalinity. Assessing chemical oxygen demand (COD) directly measures all chemical oxidizable substances, not just organic, while analyzing nutrient levels pertains to elements like nitrogen and phosphorus, which influence eutrophication rather than organic load. Thus, while they are all relevant to wastewater management, BOD specifically targets organic material quantification.