| 摘要 |
PROBLEM TO BE SOLVED: To efficiently and economically treat arsenic contained in a solution or soil.SOLUTION: A method for treating arsenic includes an arsenic oxidation step for oxidizing a trivalent arsenic contained in a solution or soil prepared to allow Fe(II)/As(III) being a molar ratio of a bivalent iron to a trivalent arsenic to be equal to or less than five into a pentavalent arsenic through the use of thermophilic iron-oxidizing bacteria. It is preferable that, before the arsenic oxidation step, steps are performed, i.e., a bacterium addition step for adding thermophilic iron-oxidizing bacteria to a solution or soil, and a bivalent iron supply step for supplying bivalent iron to a solution or soil to thereby allow Fe(II)/As(III) to be equal to or less than five before/after the bacterium addition step. It is preferable that, after the arsenic oxidation step, an arsenic immobilizing step for immobilizing a pentavalent arsenic as crystalline arsenic iron is performed. Furthermore, it is preferable that Fe(II)/As(III) is ≥1.5 and ≤3.5. |
