Water preparation device, in particular for a drain cleaning vehicle

A water treatment arrangement which can, for example, be used in a sewer cleaning vehicle is described. An exemplary arrangement includes a separation device for a supplied mud-water mixture and a water tank which is connected to it for cleaned water. The separation device and the water tank can form a structural unit. The separation device for the mud-water mixture can be surrounded, at least in areas, by the water tank for cleaned water.