The BioDoc® Trickling Filter Rotary Distributor is a patented system for optimizing the performance of trickling filters. It consists of a motor drive, a programmable logic controller (PLC) and a flexible program of speed variation designed for individual treatment plants. If power to the unit is stopped due to outage or interruption, the motor disengages the gearing, allowing the unit to spin hydraulically until power is restored. With the dosing rate optimized, the trickling filter can become the most efficient process equipment in the plant, and plant performance overall is greatly improved.
During the mid-1940’s, plant operators in England began to experiment with the speed of the rotary distributor, and corresponding effects on the performance of the trickling filter. They soon discovered the benefits of lengthening the dosing cycle to enhance plant operations. An increasing number of U.S. plants have followed this example and experienced the benefits of slowing down their trickling filters.
But slowing the distributor is only the beginning. With the benefit of ongoing research and design efforts, we’ve learned more in the past few years about enhancing the performance of trickling filters. Three operating procedures for Rotary Distributors have proven to be paramount to improving treatment plant performance:
1. A daily flushing cycle to clean the media.
2. A dosing rate to promote deeper bio-growth.
3. An operating cycle to encourage maximum wetting during peak load periods.
WesTech has designed the BioDoc® Rotary Distributor to automatically perform each of these functions, and as a result, the hundreds of BioDoc installations worldwide perform to a new level of process efficiency.
Side-by-side tests of the BioDoc modulated drive and a conventional unit revealed that, while settled BOD5 removals were similar, the BioDoc drive kept the media cleaner and improved oxygenation. Further, the results showed a 15% higher BOD5 oxidation rate, and 50% increased nitrification.