Abstract: A head flush apparatus for a pressure vessel uses an equalization chamber that channels the fluid generated by the head flush into a low volume chamber and withdraws fluid from the pressure vessel through the low volume chamber. Withdrawing fluid generated by the head flush and channeling the fluid through the low volume chamber reduces or eliminates the circulation of fluid between the equalization chamber and the adjacent process chamber and minimizes the amount of contamination that can result from any circulation of fluid resulting from pressure fluctuations. The withdrawal of fluid through the low volume chamber also provides a non-contaminating path for withdrawing leakage from the vessel.

Abstract: A random media member for a rotating biological contactor. The media member has a concave hemispherical shaped body with an inner tube with radial plate like ribs and an outer tube with radial plate like ribs, all molded together as an integral part. In one embodiment, a hollow cylinder is molded to the outside of the body. In another embodiment, parallel spaced legs are substituted for the outer cylinder. The tubes and ribs provide surfaces for bacteria to attach.

Abstract: The present invention is directed to a closed cycle aquaculture system for fish rearing which includes as part of a water treatment subsystem a rotating biological contactor. The contactor nitrifies the contaminated water to remove toxic materials therefrom and also can be operated to maintain the temperature of the water near the wet-bulb temperature of the surrounding air when desirable.

Abstract: A gas, for example, oxygen which has low solubility in water is efficiently dissolved and reacted with a substance in a flowing liquid medium by injecting the gas into the flowing liquid at spaced apart points such that a bubble flow condition is maintained and the injected gas is dissolved and substantially consumed by reaction with the substance in the interval between adjacent injection points; in this way the gas is injected at a point at which the aqueous liquid has maximum dissolving capacity and the number of injection points can be minimized; in another embodiment oxygen injection is controlled to maintain a desired oxygen:liquid ratio effective for efficient dissolving of the oxygen while maintaining the bubble flow condition, however, this requires more injection points.

Abstract: A method for sorbing metal values from a slurry containing the same is disclosed. The slurry is advanced through a plurality of vessels arranged in series while countercurrently directing a sorbent through the vessels. Metal values are sorbed from the slurry in each of the vessels by mixing the pulp to achieve homogeneity with the pulp being maintained at a predetermined level in the vessel. A portion of the homogeneous pulp is directed into an interstage screening system disposed within the vessel and at least partially submerged beneath the predetermined pulp level, whereby the sorbent is separated from the slurry. The separated sorbent is primarily returned to the vessel while a portion of the sorbent is removed from the interstage screening system.

Abstract: The present invention relates to a sample filtration device of the type employing differential pressure. An outer container filled with a sample to be filtered slidably receives a hollow plunger having filter media disposed near one end and sealing means disposed in an annular groove about the periphery of the plunger. The annular groove of the plunger is formed by two components: an annular shoulder on a collector portion and the axial face of an annular ring formed in a retainer portion. The two portions are frictionally engaged to retain the filter in place and form the annular groove for the sealing means. This construction permits straight-pull molding of the component parts which eliminates mold mismatch flaws.