A separation apparatus and method are employed using a separation channel for rotation about an axis. Such channel includes radially spaced apart inner and outer side wall portions and an end wall portion. An inlet conveys fluid into the channel. A barrier is located in the channel intermediate of the inner and outer side wall portions. A first flow path communicates between upstream and downstream sides of the barrier. A collection region may be located downstream of the barrier for communication with the first flow path. An outer side wall section of the channel may be positioned radially outward of an upstream section thereof. The barrier may join the outer side wall portion along a substantial portion of an axial length of the channel. First and second exit flow paths may allow communication with the channel either upstream or downstream of the barrier or both.