Tennessee Wastewater Operator Practice Exam

What is the DO saturation point in warm water (30 °C) at sea level?

1. 5.2 mg/L

2. 6.4 mg/L

3. 7.6 mg/L

4. 8.5 mg/L

The correct answer is: 7.6 mg/L

The dissolved oxygen (DO) saturation point in water is an important figure, as it indicates the maximum amount of oxygen that can be dissolved in water at a given temperature and pressure. At higher temperatures, like 30 °C, the capacity of water to hold dissolved oxygen decreases. This means that the DO saturation point will be lower compared to colder temperatures. In general, at sea level, the DO saturation level for water at 30 °C is approximately 7.6 mg/L. This value reflects the balance between temperature effects and atmospheric pressure, demonstrating that warmer water can hold less dissolved oxygen than cooler water. It is critical for wastewater treatment and aquatic life since oxygen levels directly affect the health of aquatic ecosystems. The other values presented do not accurately represent the expected saturation level at this temperature. Thus, 7.6 mg/L stands out as the correct answer for the DO saturation point in warm water at 30 °C at sea level.