Water Treatment Plant Operator Practice Exam

The concentration of dissolved oxygen in water is significantly influenced by temperature, and it is indeed true that colder water can hold more dissolved oxygen compared to warmer water. This relationship occurs because gas solubility in liquids generally increases as temperature decreases; thus, the oxygen molecules have more capacity to remain dissolved in cooler temperatures.

Additionally, the concept of solubility also relates to the dynamics of water, where colder temperatures reduce molecular movement, allowing more gas to dissolve. Therefore, when considering the factors that determine oxygen levels in aquatic environments, the interplay of temperature and the characteristic that colder water can support higher levels of dissolved oxygen is essential to understanding aquatic ecosystems and water treatment processes.

The other potential factors, while important in different contexts, do not capture the direct and clear effect temperature has on dissolved oxygen concentration in the same way that the presence of cold water does.