Abstract: A process for fish farming includes holding fish within a fish pond and pumping water from the pond. Dividing the pumped water into two streams, a main stream and a secondary stream. Oxygenating the water of the secondary stream by diffusing micro bubbles of oxygen into the water. The method further includes combining the oxygenated water in the secondary stream with the water in the mainstream and returning a substantial portion to the fish pond.

Abstract: A device for dissolving a gas in a liquid. The device comprises a pressure vessel or column for receiving a gas-entrained liquid via an inlet and for injecting the gas-entrained liquid via a riser into a headspace of the vessel. A flow director is disposed in an upper portion of the vessel or column to form a swirling flow path extending into a liquid pool in a lower portion of the vessel or column. An outlet is provided to direct the liquid away from the vessel or column.

Abstract: A method of removing contaminant compounds such as residual pharmaceutical or cosmetic compounds found in drinking water. The method entails directing the drinking water into a water treatment device and injecting ozone into the drinking water to form a drinking water-ozone mixture. Thereafter the water-ozone mixture is held within a holding tank where the ozone oxidizes various contaminant compounds and reduces their concentration in the drinking water. From the holding tank, the water-ozone mixture is directed to an ultraviolet light chamber where the water is treated with ultraviolet light.

Abstract: A method and arrangement for sewage pre-treatment in a sewer pipeline infrastructure upstream of a sewage treatment facility of a sewage treatment system includes selecting a site in the sewer pipeline infrastructure between a source of untreated sewage and the sewage treatment facility of the system, providing a source of a biological activity enhancing agent at the preselected site, and introducing the agent from the source thereof into a flow of untreated sewage at the selected site so as to convert the sewage from an untreated state to a pre-treated state in the pipeline infrastructure upstream of the sewage treatment facility.