Abstract: A gas-extraction arrangement for a settling tank included in a wastewater treatment system, the tank having an outlet zone defined by an effluent trough at least one side of which has a weir to permit clarified water from the tank to spill therein. The trough is covered by a hood which acts to confine the atmosphere thereabove to the hood region, at least one side of the hood protruding into the tank water at a point spaced from the weir to create a scum baffle preventing grease and other floating matter from being discharged into the trough. The hood is coupled to a suction pump which acts to draw noxious gases emitted as the water spills over the weir into a gas-control system or other means for deactivating the gases.

Abstract: A package for a flowable material such as a plant growth medium and which can be converted for use as a container for growing plants therein. The package has an elongated or square flexible outer container and is filled with the flowable filling material. The container has markings for cutting out a pair of openings at either end of the top surface to thereby leave a carrying handle in the middle.

Abstract: A multi-nozzle high pressure fluid sprayer which can be safely indexed to a selected nozzle while the sprayer is under high fluid pressure. The sprayer head contains an offset member having at least one fluid nozzle therein. The offset member can be rotated to align a selected nozzle with a source of high pressure fluid.

Abstract: A high pressure spray nozzle is provided having a central stream of fluid that can be changed to a coaxial flow of fluid by rotation of the housing cap to thereby produce an outer stream of fluid which is a coaxial to the central stream of fluid.

Abstract: A multi nozzle high pressure fluid sprayer which can be safely indexed to a selected nozzle while the sprayer is under high fluid pressure. The sprayer contains separate seals at the inlet of each nozzle to permit a safe and effective indexing to either of the nozzles while the fluid is under high pressure or to provide a total shutoff of the fluid. The sealing arrangement includes a channel to provide back pressure to the seal area around each of the nozzles to prevent the seals from being disgorged or damaged as the sprayer head is indexed from nozzle to nozzle while under high pressure.