Predicting the Performance of Belt Filter Presses Using the Crown Press for Laboratory Simulation

Abstract : Belt filter presses (BFPs) are among the most commonly used devices to dewater wastewater sludge. The concept used by a BFP to achieve dewatered cake solids is relatively simple; however, replicating this performance in the laboratory in order to predict the performance of a BFP with reasonable reliability has proven to be a challenge. The Crown Press is one tool that has been shown to replicate the performance of anaerobically digested sludge on a BFP. This study used the Crown Press to replicate and predict the performance of waste activated sludge (WAS) from the Mauldin Road wastewater treatment plant on BFPs. Several operational variables, including belt speed, belt tension, polymer type, and polymer dose, were changed on the Crown Press to predict how the changes on the BFP would affect performance. Two polymers were chosen to be tested on the BFPs at Mauldin Road based on Crown Press predictions. The first polymer performed the same as the plant's current polymer in the lab, and the second performed better (achieved higher final cake solids) than the current polymer. These predictions were borne out in the BFP tests, showing that the Crown Press predictions were accurate. The Crown Press predictions were also compared to the predictions made by the capillary suction time (CST) and specific resistance to filtration (SRF) tests. The Crown Press provided more information regarding the affect of polymer type and dose on cake solids than either CST or SRF. The Crown Press was shown to be a viable tool to assess potential changes in BFP performance with WAS when operational variables change.