Abstract: A floating decanter for removing supernatant from sequential batch reactors, clarifiers, or other similar devices. Sealed tanks support a central sump which has two peripheral openings which allow liquid to enter the sump and a cover to prevent splash over. A drain opening in the bottom of the sump allows liquid to drain out of the sump. Each of the peripheral openings has a hinged floating weir. Skirts around the drain opening in the bottom define the height of liquid in the sump upon which the floating weir rides. A barrier generally in front of and above the floating weir, prevents the surface of the liquid from entering the sump of the decanter. A horizontal plate positioned at the bottom of the sump provides a spoiler which discourages liquid from below the level of the sump from entering the sump. A plate, hinged where it joins the barrier above the weir, extends down to the lower lip of the sump.

Abstract: A floating skimmer is used for automatically removing oil and other floating matter from the surface of liquid surrounding the skimmer, preferably in a basin or sump. Floats around the periphery and above the general body of the skimmer provide flotation while the unit is at rest. Two liquid removal devices are provided, one to remove the most dense liquid (generally oil) accumulated in the skimmer sump. A gasketed, hinged, floating weir rests on the fluid level in the skimmer sump and when liquid is removed from the sump by either the first or second device or a combination of both, the weir falls back, creating a cascade action which attracts the surface of surrounding liquid into the skimmer sump. Instrumentation is included to provide information for automatic operation and status reporting of the skimmer.

Abstract: A portable liquid surface skimmer efficiently removes small spills of petroleum derivatives from the surface of water, and is useful, for example, on thin sheen spills of oil or gasoline, in boating marinas. The skimmer is controlled by a long handle held by an operator, with a swivel connection to the skimmer body. The skimmer body is placed in the water empty, to take on a controlled amount of water as ballast, putting the skimmer at a proper level to skim the surface using a floating weir. A withdrawal conduit from the skimmer's sump leads to a storage tank or more preferably to some form of separator on shore or on a dock, for further separation of water from the contaminants. In one preferred form of the system and method, the skimmed oil/water mix is passed through a special filter medium which removes the petroleum sufficiently that the water can be returned to its source, eliminating the need for hauling large volumes of liquid away to a disposal site.