Tennessee Wastewater Operator Practice Exam

Activated sludge describes a process that converts waterborne wastes into what?

1. Biomass

2. Gas

3. Liquid effluent

4. Nutrients

The correct answer is: Biomass

Activated sludge is a biological wastewater treatment process that utilizes microorganisms to break down organic matter in waterborne wastes. This process is essential for reducing pollutants in wastewater before it is discharged or treated further. When we refer to activated sludge, we are specifically highlighting the role of microorganisms, which consume organic material as their food source, leading to the production of new microbial biomass. This biomass consists of the microorganisms and the cellular material they produce, which collectively contribute to the reduction of pollutants in wastewater. During the aeration phase, these microorganisms thrive and multiply, thus converting a significant portion of the organic matter into biomass. In contrast, while gases (like carbon dioxide) and liquid effluents are indeed generated during the process, the primary focus of the activated sludge method is on biomass production as a means of effectively managing and removing contaminants from the wastewater. Nutrients also play a role in the process, as microorganisms require them to grow, but the end product of interest in the context of activated sludge is the biomass itself, which can be further processed or disposed of after treatment.