Abstract: A gas-liquid dissolving apparatus includes an intake unit that takes in to-be-treated water from an oxygen-deficient water area, an oxygen-containing gas supply unit, a bottomed gas-liquid dissolving chamber that has at least one hole formed in a lower portion and a top plate provided in an upper portion, a nozzle that ejects the gas supplied by the supplying unit and the water supplied by the intake unit, a gas-liquid separating chamber that has a gas-vent hole formed in an upper portion and a takeout port provided in a lower portion thereof, and a water supplying unit that returns the water taken out from the takeout port to the oxygen-deficient water area.

Abstract: A gas-liquid dissolving apparatus that dissolves an oxygen-containing gas into water taken in from an oxygen-deficient water area, increases a dissolved oxygen concentration of the water, and returns the increased dissolved oxygen concentration water to the oxygen-deficient water area is provided.