PNNL

Abstract

The long-time (>100 hours of operation) flux was measured for a set of tests where slurry waste simulant was separated and continuously recycled in a stainless steel crossflow filter. The tests were conducted at various constant axial velocities and transmembrane pressures. In all five tests, the flux continued to decay at long times and did not reach a steady-state. The long-time slope of the decay was unaffected by the axial velocity, and larger transmembrane pressure resulted in a larger slope. The experimental results are compared to theoretical predictions of the time to initiate cake formation and the time to reach steady-state, both of which do not imply long-time phenomena would be expected. A more reasonable match between theory and experiment was achieved using a model based on the principles of dead-end filtration.