Cation adsorbent and treatment method for solution using same

The invention relates to a cation adsorbent and a treatment method for a solution using the same. The cation adsorbent of an embodiment includes tungsten oxide particles having a BET specific surface area in a range of 0.82 m /g or more and 820 m /g or less. The cation adsorbent is added to a solution to be treated containing cations being recovery objects, and the cation adsorbent adsorbing the catious is precipitated. The generated precipitate is separated from the solution to recover the cations.