A vacuum truck has a cylindrical tank which can be pivoted to discharge through a rear door is arranged for transporting collected solids while liquid is extracted and returned. Two tank extraction outlets in the top wall at the front and rear are connected to the vacuum pump and each includes a float valve ball contained in a receptacle above the top wall as to allow the tank to be filled to the top wall. For separating the materials into liquid which is pumped away and solids for transportation, the tank includes a generally upstanding dividing wall across the tank having a bottom wall portion, which can pivot away as the tank is tilted, and has a top edge defining a weir over which liquid can flow into the liquid collection area, and an upper screening section defined by a support screen and a hanging chain curtain in front of the screen.