Question

3) With increased levels of oxidizable materials, the biochemical oxygen demand (BOD) will

A) increase.
B) decrease.
C) remain the same.
D) increase or decrease depending on the nature of the materials involved.

Answer 1

When levels of oxidizable materials increase, the biochemical oxygen demand (BOD) in a water body will increase, leading to higher oxygen consumption and potential harm to aquatic ecosystems.

Step-by-step explanation:

With increased levels of oxidizable materials, the biochemical oxygen demand (BOD) will increase. This is because more oxygen is needed for the aerobic bacterial decomposition of the additional organic matter. When a water body has an elevated concentration of organic waste, like sewage, the bacteria that break down this organic matter consume more dissolved oxygen (O₂), generating carbon dioxide and water as end products. This process can lead to oxygen depletion in the water, creating a hostile environment for aquatic life that requires higher oxygen levels.