Innovations for Optimizing Centrifuge Solids Dewatering of Undigested and Separated Primary and Thickened Waste Activated Biosolids Clark County Water Reclamation District Solids Dewatering Facility

摘要

The Clark County Water Reclamation District (CCWRD) recently completed construction of a new 180 dry ton (360,000 pound [lb]) per day (average) centrifuge dewatering facility. Because CCWRD uses biological nutrient removal (BNR) and does not digest its biosolids, several unique features were included in the design. Chief among these is the ability to keep primary solids (PS) and thickened waste activated sludge (TWAS) separated all the way through pumping, storage, and dewatering. The purpose of this is to make sure as much phosphorous as possible is removed with the dewatered biosolids, rather than being returned to the plant in the centrate. Capabilities were also provided to blend the solids prior to dewatering because this could minimize the required number of centrifuges that need to run, and will simplify operation. Other features of the facility include a highly automated truck loading facility, extensive odor control, and an automated control system with the ability to make changes to the polymer dose with changes in the solids characteristics during unmanned operation. Operational objectives include minimizing power consumption, polymer dose, and number of truckloads of dewatered biosolids to be hauled to the landfill.