A fine bubble generator may include an inlet into which gas-dissolved water in which gas is dissolved flows, an outlet out of which the gas-dissolved water flows; and a fine bubble generation portion disposed between the inlet and the outlet. The fine bubble generation portion may include a venturi portion including a diameter-reducing flow path and a diameter-increasing flow path, wherein a flow path diameter of the diameter-reducing flow path reduces from upstream to downstream, and the flow path diameter of the diameter-increasing flow path increases from upstream to downstream, a discharging flow path configured to discharge the gas-dissolved water, which flowed out of the venturi portion, out of the fine bubble generation portion; and a recirculation flow path connecting a midstream of the outflow path and the venturi portion.

An aeration apparatus for aerating water discharged from a hydraulic turbine includes: a manifold disposed within a crown of a runner of the hydraulic turbine; a plurality of radial pipes extending radially from an outer perimeter of the manifold and in fluid communication with the manifold; and one or more air injectors having a first end disposed within an aeration pipe, each of the one or more air injectors having a second end extending into a nozzle at a first end of one of the radial pipes. Rotation of the aeration apparatus resulting from rotation of the runner causes pumping of water from the manifold through the radial pipes past the one or more air injectors, and water flowing past the one or more air injectors causes air to become entrained in the water. The radial pipes discharge the water and entrained air from the aeration apparatus.

An aerator has a submersible mixing tube having a water inlet and an aerated water outlet. An aspirating tube penetrates the mixing tube between the water inlet and the aerated water outlet, the aspirating tube having an air outlet introducing air into the mixing tube and an air inlet drawing in air from atmosphere above a water surface. The mixing tube has an outboard motor lower unit engagement to engage a lower unit of an outboard motor in use such that a propeller thereof locates entirely within the mixing tube with a midsection of the outboard motor extending from the engagement. As such, the propeller of the outboard motor lower unit thrusts water past the air inlet thereby creating suction at the inlet to draw air via the mixing tube to mix with the water to expel a plume of aerated water.

A trihalomethane (THM) and volatile organic compound (VOC) removal system includes: a storage vessel; a fluid inlet on the storage vessel where fluid enters said storage vessel; a fluid outlet on the storage vessel where fluid exits said storage vessel; and a fluid fitting on said storage vessel. Fluid leaves the storage vessel via an inlet conduit attached to the fluid fitting and flows through a pump and passes through a venturi aspirator, and returns to the storage vessel through an outlet conduit attached to the storage vessel.

A diffusion system comprising an upper unit and a lower unit. The upper unit comprises a series of tubing that is situated so as to effectuate collision of the fluid and air molecules. The upper unit uses vortex winding and unwinding and pressure gradients to avoid gas and liquid separation to accomplish successful collisions between a gas and a liquid. The lower unit comprises a filtering system, liquid intake system, air intake system, and submersible liquid transportation system.

Apparatus for introducing a gas into a main medium, comprising: a main conduit for guiding the main medium, a multitude of injection lines for guiding the gas, wherein each of the injection lines has a respective end section with a respective outlet opening situated within the main conduit, and wherein the end sections are oriented essentially parallel to each other and to the main conduit. With the apparatus a gas can be introduced in particular into waste water for obtaining a biologically activated sludge. Thereby, interaction between the gas and the waste water can be particularly pronounced due to a particularly large liquid-gas-interface caused by particularly extensive turbulences. Further, shear stress acting on particles in the activated sludge can be advantageously low, thus avoiding damage of the biological particles.

An impeller-free vortex generator apparatus for fluid mixing, including: a fluid tank including: a first fluid inlet port, the first fluid inlet port including a curved flow channel between a first sidewall segment of the fluid tank and a second sidewall segment of the fluid tank, a second fluid inlet port, and a fluid outlet port; and a first fluid intake duct in fluid communication with the first fluid inlet port; wherein the first fluid intake duct is provided substantially on a tangent to the first sidewall segment of the fluid tank and aligned to deliver a first fluid to an internal surface of the first sidewall segment.

An aerating system for treating a waste lagoon or some type of wastewater that captures and recirculates air that has been previously pumped into the lagoon via a skirt. The system also utilizes an oxygen source to pump oxygen into the waste lagoon or wastewater that can also be recirculated. A manifold of the system is designed to have intakes for both the recirculated air and for the oxygen source.

The present invention provides a new carbon dioxide fixation apparatus. The carbon dioxide fixation apparatus (1) of the present invention includes: a first reaction vessel (10); a carbon dioxide fixing agent feeding unit (110); and a gas-liquid mixing unit. The first reaction vessel (10) can contain a carbon dioxide fixing agent, the carbon dioxide fixing agent feeding unit (110) can feed the carbon dioxide fixing agent into the first reaction vessel (10), and the gas-liquid mixing unit can mix a gas containing carbon dioxide into the carbon dioxide fixing agent.

There is a standpipe arrangement for holding and for supplying gas to aerators in a clarifying basin. The standpipe arrangement comprises a pipe conduit with holding means for aerators, with gas openings to the aerators and with means of fastening the pipe conduit on the base of the clarifying basin. The pipe conduit comprises several support pipes connected to each other, at the connection points of which fastening means are arranged. By way of the fastening means the support pipes are fixed both at a distance above the base of the clarifying basin as well as laterally and against rotation about the pipe axis, but can be moved along the pipe axis.