How is recirculation of affluent performed in a trickling filter?

Recirculation of affluent in a trickling filter is primarily performed to maintain a constant hydraulic load. This process involves taking a portion of the effluent from the filter and returning it to the influent. By doing so, it helps to keep a steadier flow and ensures that the filter operates under optimal conditions. Maintaining a consistent hydraulic load is essential for achieving efficient treatment, as it allows for more effective contact between the wastewater and the microbial film on the media.

When hydraulic load fluctuates significantly, it can lead to problems like underloading or overloading the filter, affecting both the treatment efficiency and the overall stability of the biological processes taking place. Thus, recirculation plays a crucial role in optimizing the performance of the trickling filter system.