Operating trickling filters in series when a primary clarifier is out of service is an effective strategy to maintain adequate treatment capacity and efficiency. This approach allows for a more continuous flow of wastewater through the system, ensuring that the biological processes occurring on the trickling filter media can still manage the organic load presented by the influent.
When in series, the first trickling filter can help reduce the organic loading to the second filter. This arrangement enhances the overall performance of the treatment process by allowing the filters to share the treatment burden, which can help in maintaining effluent quality standards. By providing an additional stage of treatment, the filters work together to compensate for the lack of primary clarification, which typically serves to remove larger solids and reduce the organic load prior to biological treatment.
In contrast, the other approaches could lead to inadequate treatment. Shutting down the trickling filters would halt the treatment process, while using only one filter at a time might not sufficiently handle the incoming flow, risking overloading and potentially causing process failures. Installing temporary clarifiers can be a resource-intensive and time-consuming solution that may not be immediately feasible, especially in emergency situations. Therefore, running the filters in series is the most practical and effective response in this scenario.