Abstract: A random media member for a rotating biological contactor. The media member has a concave hemispherical shaped body with an inner tube with radial plate like ribs and an outer tube with radial plate like ribs, all molded together as an integral part. In one embodiment, a hollow cylinder is molded to the outside of the body. In another embodiment, parallel spaced legs are substituted for the outer cylinder. The tubes and ribs provide surfaces for bacteria to attach.

Abstract: A biological reactor and media members wherein the reactor is made up of a hollow drum having end shields with openings in the drum periphery so that liquid can flow through the drum periphery. The drum is supported by outwardly extending shafts attached to end shields and no shaft section is disposed inside the drum. Hemispherical shaped hollow media members with internal ribs are supported in the drum for bacteria to form on and legs are attached to the outside of the hollow media members to engage other media members and thus, providing further agitation. About forty percent (40%) of the drum is disposed in the liquid.