Abstract: A sludge blanket-clarified liquid interface detector apparatus for a wastewater treatment process including a floating decanter assembly preferably includes a sludge detector light source and light sensor pair positioned in spaced apart relation on a sludge layer detector frame which is suspended in depending relation below the floating decanter assembly. The light sensor is interfaced to a process controller to which is also interfaced a decanter valve which flow controls the decant cycle of the process. As the decant cycle proceeds, the decanter assembly descends along with the falling level of liquid in the process reactor until the detector descends past the interface and into the sludge layer. The decrease in light transmission between the light source and sensor is signaled to the controller which causes the decanter valve to close to end the decant cycle to prevent the discharge of polluting sludge from the reactor.

Abstract: An aeration and mixing apparatus for use in a wastewater treatment facility is mounted on a float and includes an axial-flow mixer having a stem that extends through a flow channel in the float, a diffuser cone slidingly mounted on the mixer stem and a diffuser hood fixedly attached to the diffuser cone and located below the float. A diffuser-drive mechanism mounted on the float transfers the diffuser cone and attached diffuser hood between a first, aeration position and a second, anoxic-mixing position. In the first position, the cone is spaced above the channel of the float and the diffuser hood abuts a bottom surface of the float with wastewater being propelled by the mixer upwardly through the hood and flow channel onto the diffuser cone where it is dispersed outwardly in the air above the float.

Abstract: A decanter and support assembly includes a pair of mooring arms pivotally attaching the decanter to a wall of a wastewater reactor basin and hingedly attached to a float buoyantly supporting the decanter. The decanter includes a valve for controlling the draw of liquid thereinto and a flexible discharge conduit that is fixedly attached to the decanter. A control line for powering the valve is mounted at the top of the non-detachable mooring arm. The float supports an actuation device which is operably connected to the control line. In a first embodiment of the decanter valve, the valve is oriented generally vertically at the inlet of the flexible conduit. In a second embodiment of the decanter valve, an actuator mechanism moves an exterior valve hood with a sealing flange which seals the discharge conduit against liquid. The valve hood sleeves a generally cylindrical intake manifold that supports the decanter.

Abstract: An apparatus for use in the biological treatment of contaminated water with activated sludge utilizing a sequencing batch reactor process, fixed film media reactor or the like and, in particular, for supplying oxygen rich gas to the proces. Air is located on one side of an oxygen permeable membrane under a differential pressure urging oxygen in the air to pass through the membrane for separating the oxygen from nitrogen in the air. The oxygen downstream of the membrane is conveyed by a gas line leading to a circulation manifold located in the reactor. Jet nozzles on the circulation manifold communicate with oxygen in the gas line. When activated sludge and wastewater are pumped into the circulation manifold and forced through the jet nozzles, a vacuum is created therein drawing the oxygen rich gas from the membrane into the nozzles and pumping the resulting liquid/gas mixture into the reactor, mixing the oxygen with the wastewater.

Abstract: A pressure responsive valve assembly for use in a decanting apparatus for a wastewater treatment reactor. The valve assembly includes a cylindrical valve plate, a valve member support structure, a valve spring, and a valve member comprising a valve stem and a valve head. A discharge passageway extending through the valve plate has a frusto-conical valve seat located therein. The valve head also has a frusto-conical design having an angle of divergence smaller than that of the valve seat so that when the valve head is biased against the valve seat by the valve spring, the valve seat sealingly engages a peripheral edge of the valve seat. The valve member support structure maintains the valve member in proper alignment with the valve seat and in engaging relationship with the valve spring.

Abstract: A process strategy for the treatment of wastewater in a sequencing batch reactor wherein wastewater in quantities above a preselected minimum amount is proportionally aerated so as to reduce energy usage and operating costs.