The present invention provides an improved solids removal and concentrating unit. The solids removal and concentrating unit comprises a tank, an inlet line, an outlet line, and a sludge removal line communicating with the tank. The solids removal unit further has a plurality of linear baffles positioned in the tank forming a baffle row, with the baffles being positioned in a substantially vertical orientation. Finally, the tank further has a plurality of baffle rows. The baffles operate to reduce the velocity of a carrier liquid behind the baffles. The baffles also operate to form slight vortexes in the carrier liquid behind the baffles and thereby facilitate the downward movement of solids.