California Wastewater Treatment Operator Practice Exam

What should be the operational strategy for a wastewater treatment plant with at least 2 trickling filters if a primary clarifier is out of service?

1. Switch to batch processing

2. Operate the trickling filters in parallel

3. Operate the trickling filters in series

4. Enhance chemical dosing

The correct answer is: Operate the trickling filters in series

When a primary clarifier is out of service at a wastewater treatment plant that utilizes trickling filters, operating the trickling filters in series is the most effective operational strategy. Operating trickling filters in series allows for more efficient treatment of the wastewater that is bypassing the primary clarifier. This configuration ensures that the effluent from the first trickling filter is subjected to additional biological treatment by the second one, enhancing the overall removal of organic matter and nutrients. The sequential arrangement can help in achieving a higher level of treatment efficiency, as each filter can provide additional contact time and surface area for the microorganisms to break down contaminants. While operating the trickling filters in parallel might seem advantageous for maximizing flow capacity, it may not provide the same level of treatment efficacy as a series configuration when dealing with increased loading due to the absence of primary clarification. Additionally, an enhancement in chemical dosing could potentially assist in improving the treatment process, but it would not substitute the biological treatment that is essential when a primary clarifier is out. Batch processing is generally not applicable to continuous flow systems like trickling filters, where the aim is to maintain a consistent treatment process. Therefore, utilizing the trickling filters in series is the most appropriate approach to ensure that the wastewater receives adequate