An aeration nozzle is provided, having on one end an air supply port (16a) connected to an aeration pump (13) and a waste water suction port (17) for suctioning waste water in a processing tank (3, 4), and having a micro-bubble generation unit (18), provided facing the air supply port, for mixing air supplied by the air supply port and waste water suctioned from the waste water suction port and generating micro-bubbles (9), wherein a plurality of blades of cylindrical micro-bubble generators (19) included in the micro-bubble generation unit (18) is configured such that tip ends of the blades are formed so as to face one another around the center of the cylindrical micro-bubble generators (19a, 19b); and by being formed from an elastic member (such as rubber), the tip ends of the blades are configured so as to bend with the base ends as starting points.

A functional water producing apparatus in an embodiment includes: a water pressure regulator configured to regulate the water pressure of the ultrapure water, the water pressure regulator having a pressure regulating valve configured to regulate a water pressure of the ultrapure water to an almost constant pressure and a feed water pump configured to pressurize the ultrapure water; a dissolving device configured to dissolve functional gas imparting a specific function in the ultrapure water regulated the water pressure by the water pressure regulator; and a control device configured to control the feed water pump to regulate the water pressure of the functional water to a predetermined constant pressure based on a water pressure or a flow rate of the functional water flowing out of the dissolving device.

A fluid distribution device for a gas-liquid contactor the device having a first side, a second side and a plurality of through-holes extending from the first side to the second side, through which holes a first fluid can flow. The fluid distribution device further having an interior, which is delimited by the first side and the second side and which is sealed in a fluid-tight manner in relation to the through-holes, a plurality of openings, which connect the interior to the second side, and a fluid connection, through which a second fluid can be introduced into or evacuated from the interior. A gas-liquid contactor having a fluid distribution device of this type and to a method for adding a gas to a liquid is also disclosed.

A blow-molding plastic bubble-generating device is provided, including a board-like shell body. The board-like shell body is formed through blowing a hollow embryo placed in a mold, the hollow embryo is blown and expanded, the hollow embryo is penetrated through by a plurality of needle posts on an inner wall of the mold to form the board-like shell body, the board-like shell body is integrally formed and hollow and has a shell wall which completely and continuously surrounds the board-like shell body, and the shell wall has a plurality of through holes.