A positive pressure disc-type filtration apparatus including a collection trough internal to the cylindrical pressure vessel housing the filter discs. The collection trough is entirely disposed within the cylinder of the pressure vessel and configured and located to receive and direct filter cake removed from the discs and then reslurried and sluiced toward the center of the trough using jets of liquid, to be discharged longitudinally centrally through a single outlet extending downwardly from the trough and through the wall of the pressure vessel. A method of filtration is also disclosed.