Abstract: An oxidation ditch for circulating a waste water stream and having a channel formed by a continuous vertical outside wall extending upward from a bottom and having at least one section shaped to form a curved area into which a vertical turbine is operatively positioned and by a partition wall also extending upward from the bottom and positioned inside the outside wall with one of its ends adjacent the vertical turbine, the improvement of which comprises a baffle positioned in the channel upstream of the vertical turbine to minimize the mixing of the upstream waste water with the backwash created by the vertical turbine.

Abstract: Operation of an intra-channel clarifier within a circulating sewage stream can be enhanced by flow adjusting vanes positioned within the sewage stream between the clarifier and channel wall, proximate to the clarifier sludge ports. In a preferred embodiment, the vanes are aligned perpendicular to the flow of the stream, on a vertical axis. The vanes are divided into an independently adjustable upper and lower portion which can be used to direct the sewage flow and alter the cross sectional area of the sewage stream in the vicinity of the clarifier. The rate at which sludge is removed from the clarifier is affected by the velocity of the sewage stream beneath the sludge ports as well as any turbulence or eddy currents which are produced.

Abstract: A process for treating wastewater to biologically remove phosphorous as well as lowering ammonia, TSS and BOD levels is provided. The process employs a plurality of basins which may be individually controlled to achieve anaerobic, anoxic or aerobic conditions. The basins are reconfigurable in that the flow of influent to a basin, transfer of mixed liquor between basins and effluent discharge from a basin can be varied to create a treatment cycle which has features of both continuous and batch processes while minimizing recycle rates and hydraulic level changes.

Abstract: A treatment system for water or wastewater is provided, comprising a tank having a substantially circular continuous sidewall and a bottom; a mixing device, for mixing and circulating liquid within the tank, positioned within the tank; and an intra-channel clarifier, positioned within the tank between the center of the tank and the sidewall such that the clarifier will be partially submerged when the tank contains liquid, the clarifier including a bow, a stern, side walls, an entry opening and at least one discharge port in the bottom, the clarifier having an elongated shape such that the side walls are generally parallel to the sidewall of the tank.

Abstract: A skimmer system is provided for structures having a floor, two side walls and at least one open end, the structure being semi-submersibly positionable in a moving liquid stream. The skimmer system comprises at least one side trough having a bottom, an interior trough wall and an exterior trough wall. The exterior trough wall is coincident with the interior side of one side wall of the structure and is provided with at least one opening communicating betweeen the interior of the trough and the exterior of the structure. The interior trough wall is provided with at least one opening communicating between the interior of the trough and the interior of the structure.

Abstract: A turbulence control system is provided comprising a first baffle, fixedly connected across the interior of an intra-channel clarifier having side walls between the side walls near the point of entry of wastewater into the clarifier, the first baffle covering a desired portion of the cross-sectional flow area within the clairifier; and a second baffle, fixedly connected across the interior of the clarifier between the side walls downstream of the first baffle and covering a desired portion of the cross-sectional flow area left uncovered by the first baffle. The turbulence control system may also comprise at least one accumulation baffle, connected between the side walls and near the bottom of the clarifier, the accumulation baffle extending upward to a desired height within the clarifier, but not so high as to produce a flow velocity which would impede settlement of sludge within the clarifier.

Abstract: A filter for use in conjunction with an intrachannel clarifier is provided comprising an enclosure, positionable within a channel and connectible to an intrachannel clarifier, and having a floor and sides; a filter compartment fixed within the enclosure, and having sides, either connected to or coincidental with the sides of the enclosure and segregating the interior of the filter compartment from the remainder of the enclosure; a porous medium support, fixedly connected to the sides of the enclosure and positioned within the filter compartment; a bottom, below the medium support and fixedly connected to the sides of the filter compartment; a filter medium, positioned within the filter compartment above the medium support; a conduit, connecting between the interior of the filter compartment beneath the medium support and the interior of the enclosure; a liquid dispersion mechanism, positioned within the filter compartment above the filter medium, for receiving liquid from outside the enclosure and dispersing

Abstract: A side skimmer provided in a channel containing flowing liquid includes a skimmer mechanism and a skimmer drain. The skimmer mechanism includes a fixed portion secured in a hinge-like manner to one side of the channel and aligned with an obstruction located partially across the channel width, and a movable wing-like portion extending above and below the liquid surface. This mechanism selectively deflects the flow into the drain, and is movable between a closed position, which allows free flow between the mechanism in the channel side and the obstruction, and an open position between the fixed portion and the obstruction, which directs flow to the skimmer drain. The skimmer drain is vertically movable between a closed position above the liquid surface, and an open position just below the surface whereby floating matter is removed.