Tennessee Wastewater Operator Practice Exam

What is one purpose of primary treatment in wastewater management?

1. To perform disinfection

2. To remove sludge and scum

3. To aerate the wastewater

4. To chemically neutralize harmful substances

The correct answer is: To remove sludge and scum

Primary treatment in wastewater management primarily aims to remove large solids, sludge, and scum from the wastewater before it undergoes further treatment. This process is crucial because it helps to reduce the load on subsequent treatment processes, such as secondary treatment, which focuses more on removing dissolved and suspended organic matter through biological processes. By effectively removing heavier solids and floating materials during primary treatment, the process helps to protect downstream equipment from damage, ensures more efficient operation, and improves the overall quality of the effluent. This means that the water can be treated more effectively in later stages, leading to better overall treatment outcomes and compliance with environmental regulations. The other choices, while relevant to different stages of wastewater treatment, do not correctly represent the primary treatment. Disinfection occurs later in the treatment process after secondary treatment; aeration is a key aspect of secondary treatment that promotes the growth of microorganisms; and chemical neutralization is typically involved in managing pH levels in certain treatment scenarios rather than serving as a primary treatment function.