Florida Wastewater Practice Test

In biological treatment, in what form are nutrients better utilized by microorganisms?

1. Solid

2. Gas

3. Liquid

4. Soluble

The correct answer is: Soluble

Microorganisms in biological treatment processes, such as those used in wastewater treatment, are more effective at utilizing nutrients when they are in a soluble form. Nutrients like nitrogen and phosphorus must be dissolved in water to be readily available for microbial uptake. When these nutrients are soluble, they can easily diffuse across the cell membranes of microorganisms, facilitating efficient absorption and metabolism. In contrast, nutrients that are in solid or gas form are less accessible to microorganisms. Solid nutrients require breakdown into smaller, soluble molecules before microbial uptake can occur, which can slow down the treatment process. Similarly, gaseous nutrients do not readily dissolve in the aqueous environment necessary for biological treatment, limiting their use by microorganisms. Therefore, soluble nutrients are paramount in promoting the growth and activity of microbial populations that perform crucial functions during wastewater treatment.