The Effect of Orifice Flow Treatment on Biosludge Dewaterability

This research assessed the potential for orifice flow treatment to improve biosludge dewaterability by disintegrating the flocs, thereby releasing the interstitial water trapped within them. Pulp and paper waste activated sludge, municipal waste activated sludge, and municipal anaerobically digested sludge samples were orifice flow treated at strain rates up to 29,280 ± 1060 s-1, 34,540 s-1, and 34,090 s-1, respectively, and their particle size distribution, water distribution, and dewaterability were assessed. Although orifice flow treatment disintegrated the biosludge flocs, it did not significantly affect the interstitial water content. Overall, orifice flow treatment worsened filterability. Orifice flow treatment did, however, increase the centrifuge cake solids content of pulp and paper and municipal waste activated sludge by 10 and 15 % respectively, showing the potential to improve biosludge centrifugability. Additionally, orifice flow treatment was more effective in disintegrating pulp and paper waste activated sludge flocs than sonication at the same energy output.M.A.S