California Wastewater Treatment Operator Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

COD and BOD are both parameters used to measure the organic content in wastewater, but they do so in different ways. COD directly measures the amount of oxygen required to oxidize organic matter, while BOD measures the amount of oxygen consumed by microorganisms in breaking down organic matter. Therefore, neither A nor B is the correct answer. Additionally, D is incorrect as both COD and BOD are closely related to wastewater treatment processes. Overall, C is the correct answer because although these measurements indirectly measure the organic content, they do so in different ways and are both integral to understanding and managing wastewater treatment processes.