Abstract: The invention provides a fluid treatment apparatus including a fluid bed reactor. The fluid bed reactor includes a flow distribution system having a flow distributor for introducing untreated fluid into the reactor. The untreated fluid is introduced at a flow rate sufficient to generate an upflow velocity within the reactor that fluidizes the media bed within the reactor. The flow distribution system also includes a backflow prevention apparatus for supplying an auxiliary fluid to the flow distributer in the event flow of untreated fluid to the flow distributor is interrupted. The auxiliary fluid flushes the flow distributor while the media bed defluidizes to prevent the media bed from backing up into the flow distributor as it settles to the bottom of the reactor.

Abstract: Disclosed herein is a treatment facility comprising a fluid bed reactor including a reactor tank containing a bed of particles which function as a carrier for growth of biological material, the reactor tank having an inlet and an outlet, the reactor further including structure for conducting liquid to be treated, from the reactor tank inlet, upwardly through the bed of particles at a rate conducive to fluidization of the bed of particles; an equalization surge tank for housing liquid to be treated in the fluid bed reactor, the equalization surge tank having an inlet, and an outlet; conduit structure for supplying liquid from the outlet of the equalization surge tank to the inlet of the fluid bed reactor; and structure for supplying an oxidant into the equalization surge tank, in such a manner that stripping of volatile constituents is avoided, for oxidizing iron in the liquid in the equalization surge tank.