Nano-bubble generating apparatus and method

An apparatus for producing nano-bubbles in a moving liquid, comprising:

• an elongate conduit having an opening extending axially from a first end to a second end through which the moving liquid can flow, wherein the elongate conduit is elongate in a direction extending from the first end to the second end, the elongate conduit further comprising a gas diffuser disposed on an inner surface of the elongate conduit, the gas diffuser comprising an outer surface configured to contact the moving liquid flowing through the elongate conduit, the gas diffuser comprising a plurality of pores configured to receive a gas from a gas source and transport the gas to the outer surface of the diffuser;
• and
• a funnel comprising:
• a first open end configured to receive the moving liquid, the first open end defining a first cross-sectional area;
• a second open end opposite the first open end, the second open end defining a second cross-sectional area that is smaller than the first cross-sectional area, the second open end fluidly coupled to the opening of the elongate conduit;
• and
• a wall extending from the first open end to the second open end, wherein the wall of the funnel with respect to the inner surface of the elongate conduit defines an angle of less than 45 degrees, wherein the funnel, due to the angle of less than 45 degrees, and the elongate conduit, due to the length of the elongate conduit from the first end to the second, are configured to generate a flow velocity in the moving liquid received by the opening sufficient to create turbulent flow above a turbulent threshold in the absence of external energy that allows the moving liquid to shear gas from the plurality of pores at the outer surface of the diffuser, thereby forming nano-bubbles at a concentration of at least 1×106 nano-bubbles per milliliter in the moving liquid.