An orbital wastewater treatment system includes a tank and a partition
disposed in the tank to define a pair of channels in the tank. The tank
has a turning wall bounding contiguous portions of the channels. The
partition has an end spaced from the turning wall, whereby the channels
communicate with one another. A driven shaft is disposed vertically in
the tank between the end of the partition and the turning wall. The
driven shaft is provided at an upper end with a surface aerator and at a
lower end with a horizontal impeller. At least one baffle member is
disposed in the tank partially about a lower end of the shaft including
the impeller.