Tennessee Wastewater Operator Practice Exam

What factors influence ORP readings?

1. Temperature and water quality

2. pH levels and turbidity

3. Water pressure and chemical additives

4. Temperature and sediment concentration

The correct answer is: Temperature and water quality

Oxidation-Reduction Potential (ORP) readings are significantly influenced by both temperature and water quality. The temperature of the water can affect the chemical reactions taking place, which in turn impacts the ORP readings. For instance, higher temperatures typically increase the rate of chemical reactions, which can lead to more oxidizing or reducing conditions. Water quality is also a crucial factor, as it encompasses various characteristics such as the presence of dissolved oxygen, organic and inorganic contaminants, and overall chemical composition. These elements directly alter the oxidation-reduction reactions occurring in the water. Cleaner, well-oxygenated water typically has higher ORP values, whereas water with high levels of pollutants may exhibit lower ORP values due to the presence of reducing agents. Other options, while containing noteworthy elements that can influence water quality, are not as directly impactful on ORP readings as temperature and overall water quality are. For example, pH levels can influence ORP, but they are not as dominant as the combined effects of temperature and water quality. Thus, focusing on the impact of both temperature and the broader definition of water quality provides a more comprehensive understanding of ORP reading fluctuations.