An apparatus for producing a composition that includes nano-bubbles dispersed in a liquid carrier includes: (a) an elongate housing comprising a first end and a second end, the housing defining a liquid inlet, a liquid outlet, and an interior cavity adapted for receiving the liquid carrier from a liquid source; and (b) a gas-permeable member at least partially disposed within the interior cavity of the housing. The gas-permeable member includes an open end adapted for receiving a pressurized gas from a gas source, a closed end, and a porous sidewall extending between the open and closed ends having a mean pore size no greater than 1.0 m. The gas-permeable member defines an inner surface, an outer surface, and a lumen. The housing and gas-permeable member are configured to form a composition that includes the liquid carrier and the nano-bubbles dispersed therein.

A reactor for treating water, the reactor comprising a buoyant structure for supporting at least one cell for suspension in a body of water in use, wherein each cell is removeably attachable to the buoyant structure and is arranged to house biomedia. A water treatment system comprising the reactor in a body of water. A method of treating water comprising passing water to be treated through the reactor in a body of water.

A stabilized, gas-infused liquids containing ultra high concentrations of infused gas, produced by: generating a gas-infused liquid in a sealed vessel under a high pressure of at least 20 psi; stabilizing the gas-infused liquid by passing the liquid while still under the high pressure through a tubular flow path arrangement which compresses the infused gas into nano bubbles in the liquid; infusing an additional amount of the gas into the stabilized liquid by injecting the same, while still under high pressure, back into the sealed pressure vessel along with more of the gas; and again stabilizing the liquid by again passing liquid, while still under the high pressure, through the tubular flow path arrangement to thereby form the additional amount of infused gas into nano bubbles in the liquid.

A stabilized, gas-infused liquids containing ultra high concentrations of infused gas, produced by: generating a gas-infused liquid in a sealed vessel under a high pressure of at least 20 psi; stabilizing the gas-infused liquid by passing the liquid while still under the high pressure through a tubular flow path arrangement which compresses the infused gas into nano bubbles in the liquid; infusing an additional amount of the gas into the stabilized liquid by injecting the same, while still under high pressure, back into the sealed pressure vessel along with more of the gas; and again stabilizing the liquid by again passing liquid, while still under the high pressure, through the tubular flow path arrangement to thereby form the additional amount of infused gas into nano bubbles in the liquid.

A computer-implemented method of closed-loop dissolved oxygen monitoring and control at a hydroelectric plant includes: regulating at least one aeration valve coupled to a turbine using pattern recognition; wherein a target parameter for the regulating is a dissolved oxygen concentration of water downstream of the hydroelectric plant. The dissolved oxygen concentration may be at least 5.0 milligrams per liter. The pattern recognition may be performed using a neural network.

A computer-implemented method of closed-loop dissolved oxygen monitoring and control at a hydroelectric plant includes: regulating at least one aeration valve coupled to a turbine using pattern recognition; wherein a target parameter for the regulating is a dissolved oxygen concentration of water downstream of the hydroelectric plant. The dissolved oxygen concentration may be at least 5.0 milligrams per liter. The pattern recognition may be performed using a neural network.

An artificial-whirlpool generator includes a whirlpool generating member including at least one water inlet, a whirlpool generating chamber communicating with the water inlet, and a whirlpool outlet that is formed at a lower end portion of the whirlpool generating member and communicates with the whirlpool generating chamber; a position-fixing means that fixes the whirlpool forming member such that the entirety of the whirlpool generating member or only a portion of the whirlpool generating member, including the whirlpool outlet is submerged; and a swirling flow forming unit that forces water in a waterbody to be introduced into the whirlpool generating chamber through the water inlet and rotates the introduced water in one direction around an axle provided at a center portion of the whirlpool generating chamber to form a whirlpool that descends toward the whirlpool outlet.

An artificial-whirlpool generator includes a whirlpool generating member including at least one water inlet, a whirlpool generating chamber communicating with the water inlet, and a whirlpool outlet that is formed at a lower end portion of the whirlpool generating member and communicates with the whirlpool generating chamber; a position-fixing means that fixes the whirlpool forming member such that the entirety of the whirlpool generating member or only a portion of the whirlpool generating member, including the whirlpool outlet is submerged; and a swirling flow forming unit that forces water in a waterbody to be introduced into the whirlpool generating chamber through the water inlet and rotates the introduced water in one direction around an axle provided at a center portion of the whirlpool generating chamber to form a whirlpool that descends toward the whirlpool outlet.

An apparatus for producing a composition that includes nano-bubbles dispersed in a liquid carrier includes: (a) an elongate housing comprising a first end and a second end, the housing defining a liquid inlet, a liquid outlet, and an interior cavity adapted for receiving the liquid carrier from a liquid source; and (b) a gas-permeable member at least partially disposed within the interior cavity of the housing. The gas-permeable member includes an open end adapted for receiving a pressurized gas from a gas source, a closed end, and a porous sidewall extending between the open and closed ends having a mean pore size no greater than 1.0 m. The gas-permeable member defines an inner surface, an outer surface, and a lumen. The housing and gas-permeable member are configured to form a composition that includes the liquid carrier and the nano-bubbles dispersed therein.

A safety access system for use on floats, typically in the field of water and wastewater treatment, the system including rotatable and removable handrails and sockets attached to the float to receive the handrails.