This paper investigates the separation of anionic oligosaccharides produced by thermal degradation at 120 degrees C of polygalacturonic acids (PGA). Initially, the PGA solution was clarified by two successive centrifugations. These centrifugations were later replaced by two microtiltrations (MF) which did not modify oligosaccharides composition. A dynamic filtration module with a disk rotating at 2000 rpm near a circular organic membrane was used in all filtration steps. Several micro- and ultrafiltrations (MF and UF) in cascade (50, 20, and 10 kDa) and a nanofiltration at 1 kDa were used to separate oligomers with degrees of polymerization (Dp) <= 7. Permeate fluxes ranged from 400 Lh(-1) m(-2) for the first MF to 240 Lh(-1) m(-2) for the 10 kDa UF and 60 to 100 Lh(-1) m(-2) for the 1 kDa NF, showing the high potential of dynamic filtration for this application.