A drum-type filtration system for the separation of a liquid phase and a solid phase, comprising: - a frame, which forms at least one first tank for collecting a mixture of a liquid phase and a solid phase to be separated; - a drum-type filtering assembly, which is supported by said frame so that it can rotate about its own longitudinal axis and is at least partially immersed in said first tank, which is adapted to retain on its outside the solid phase and inside which the liquid phase evacuated through at least one discharge port formed at an end face is collected; - means for rotary actuation of said filtering assembly about its own longitudinal axis; - means for washing said filtering assembly, which are arranged at least partially inside it and operate outward to remove the solid phase retained outside said filtering assembly; - means for collecting and evacuating the solid phase removed from said filtering assembly during washing; and wherein said collection and evacuation means comprise at least one wall, which is contoured so as to form a substantially cylindrical portion whose axis of symmetry is parallel to the longitudinal axis of said filtering assembly, which is arranged inside said first tank and below said filtering assembly for the deposit of the solid phase removed during washing, at least one channel for collecting the solid phase arranged substantially parallel to the longitudinal axis of said filtering assembly and proximate to said wall, means which scrape said wall, are supported outside said filtering assembly, can move so as to rotate about said axis of symmetry, and are adapted to transfer the solid phase deposited on said wall into said channel, and means (12, 21, 22, 23, 24, 25, 26) for extracting said solid phase from said channel, characterized in that said frame comprises a second tank for collecting the liquid phase separated by said filtering assembly, which is connected to said discharge port and isolated from said first tank and a third tank, which is connected to said first tank and in which at least one conveyor belt is accommodated which is at least partially immersed and cooperates in removing the solid phase, said filtering assembly being included in a pre-filtration section that is entirely independent of said conveyor belt, the conveyor belt being suitable for delay-timing operation for sedimentation of solid phase thereon and further pre-filtration before the mixture of liquid and solid phases enters said first tank. - a frame, which forms at least one first tank for collecting a mixture of a liquid phase and a solid phase to be separated; - a drum-type filtering assembly, which is supported by said frame so that it can rotate about its own longitudinal axis and is at least partially immersed in said first tank, which is adapted to retain on its outside the solid phase and inside which the liquid phase evacuated through at least one discharge port formed at an end face is collected; - means for rotary actuation of said filtering assembly about its own longitudinal axis; - means for washing said filtering assembly, which are arranged at least partially inside it and operate outward to remove the solid phase retained outside said filtering assembly; - means for collecting and evacuating the solid phase removed from said filtering assembly during washing;