California Wastewater Treatment Operator Practice Exam 2025 - Free Wastewater Treatment Operator Practice Questions and Study Guide

BOD stands for Biochemical Oxygen Demand, which is a crucial parameter in wastewater treatment. It measures the amount of oxygen that microorganisms will consume while decomposing organic matter in a water sample over a specific period, usually five days at a temperature of 20 degrees Celsius.

This measurement is significant because it provides an indication of the organic pollution level in the wastewater. A higher BOD value suggests a greater amount of biodegradable organic material present, which can lead to oxygen depletion in receiving waters if not adequately treated. Understanding BOD helps wastewater treatment operators design appropriate processes to reduce the organic matter in wastewater and ensure that the effluent meets environmental standards before it is discharged back into natural water bodies. This makes it vital for assessing the efficiency of treatment methods and the potential impact on aquatic ecosystems.