Troubleshooting an Existing RBC (Rotating Biological Contactor) Facility,
Abstract:
Analysis of the problems experienced with the RBCs at the Kirksville WWTP indicated that performance problems are associated with organic overloading. It also appears that organic overloading is the principal contributing cause of the large number of shaft failures that have been experienced. This organic overloading results in excessive growth of biomass which is not sloughed, and causes structural overloading of the RBC shafts. Aeration effectively increases biomass sloughing, reducing the structural loads on the shafts. At the Kirksville WWTP, aeration of the first three bays in each train at 200 cfm should provide adequate biomass sloughing to maintain structural loads at allowable levels, under current and projected future organic loading conditions. Some improvement in process performance for SBOD5 removal appeared to result from aeration. However, it was concluded that at the design organic loading the WWTP will likely not meet its performance objective even with reasonable supplemental aeration. Supplemental aeration, combined with reductions in loadings to levels recommended by the manufacturer, will be required to provide adequate wastewater treatment.