Abstract: A media panel for a rotating biological treatment apparatus for treating waste water, the rotating biological treatment apparatus including a rotatable shaft having a longitudinal axis and a plurality of media panel assemblies stacked on the shaft and each including a hub mounted on the shaft and a plurality of media panels mounted on the hub, the media panel comprising a planar member having a first side and a second side, and the planar member being mountable on the hub to extend normal to the longitudinal axis of the shaft to form a portion of a generally disk-shaped media panel assembly extending normal to the longitudinal axis of the shaft; the first side of the planar member including at least one first set of alternating grooves and ridges, and the second side of the media panel including at least one second set of alternating grooves and ridges; the grooves and ridges of the first and second sets of alternating grooves and ridges each having a first radially inner portion, a second radially inner port

Abstract: A wastewater treatment apparatus is disclosed in which a rotating biological contactor rotatably mounted on a horizontal shaft is deeply submerged in a wastewater tank, so that a substantial portion of attached biomass does not come into contact with the ambient air. A plurality of gas conduits are disposed in the tank beneath the rotating contactor and are positioned to provide rotational energy to the contactor, to serve as the principal source of oxygen for the submerged biomass and to regulate the rotational velocity of the biological contactor so that the oxygen containing air bubbles are caused to rise into the central region of media rather than being swept along and confined to the outer radius of the media as it rotates.