Abstract: An apparatus for wastewater filtration having a barrel, a basket and a screw on a shaft rotating therein for pushing solid in a distinct output. A removable cartridge comprises a cover for the barrel, the cartridge comprising a pre-sealed shaft connector which releasably connects to at least the upper shaft portion or the lower shaft portion to form the shaft. The screw comprises a brush on an outer rim thereof, the brush having radially outwardly oriented bristles that scrape an inner surface of the basket. The screw comprises a winged wiper at a bottom thereof for sweeping a bottom surface of the barrel, and the solid-material output is provided at the bottom surface of the barrel and is shaped as a rectangular opening which is offset from a central axis of the screw. Solid removal efficiency and maintenance are thereby improved.