Method for recovering pulp fiber from used hygiene product

A method of recovering pulp fibers from a used hygiene product which includes pulp fibers and a polymer absorbent material, the method comprising:

• introducing the used hygiene product into a treatment tank with an ozone dissolved aqueous solution;
• and
• decomposing the polymer absorbent material to lower a molecular weight of the polymer absorbent material and make the polymer absorbent material dissolvable,
• wherein said decomposing comprises treating the used hygiene product under a circulation mode by
• injecting water into the treatment tank by a first flow rate,
• discharging the aqueous solution from the treatment tank by a second flow rate, and
• introducing an ozone containing gas into the aqueous solution inside the treatment tank, wherein
• a product of an ozone concentration (mass ppm) of the aqueous solution and a time (minute) of the treating the used hygiene product is 100 to 6000 mass ppm·minute.