[en] A crossflow filtration campaign to remove entrained solids and precipitated solids from Hanford Tank 241-AN-102 Envelope C was completed. A 0.61 m (2-foot) long, 0.0095 m (3/8 inches) internal diameter, 0.1 micron pore size Mott crossflow filter tube was used. An Envelope C (241-AN-102) sample containing entrained solids was then successfully pretreated for removal of strontium-90 and transuranic activity. The 1.2-liter sample was caustic adjusted, strontium and permanganate precipitated, and crossflow filtered in a bench scale demonstration. Filtration fluxes for the precipitate ranged from 2.93 to 8.80 m³/(m²day) [0.05 to 0.15 gpm/ft²]. Transmembrane pressures were in the range of 2.06 to 4.83 bar [30 to 70 psid] and crossflow velocities were in the range of 2.8 to 4.6 m/s [9 to 15 ft/s]. The filtrate product was decontaminated for strontium by a factor of 30 (1.7 uCi/ml at 5.8 M sodium). This work provides important confirmation of the new process to achieve both acceptable filterability and decontamination for Envelope C wastes to be treated by the Hanford River Protection Project (RPP)