Method for treating arsenic-containing aqueous solution

摘要

Provided is a method for treating an arsenic-containing aqueous solution by water treatment employing a titanium dioxide photocatalyst that is excellent in both photocatalytic activity and solid-liquid separation performance. The method according to the present disclosure includes the steps: of adding catalyst particles to the aqueous solution; oxidizing trivalent arsenic by irradiating the aqueous solution with light having a wavelength of 200 nanometers or more and 400 nanometers or less while stirring the catalyst particles in the aqueous solution; and stopping the stirring and separating the catalyst particles from the aqueous solution by sedimentation. Each catalyst particle is composed only of a titanium dioxide particle and a zeolite particle, the titanium dioxide particle is adsorbed on the outer surface of the zeolite particle, the zeolite particle has a silica/alumina molar ratio of 10 or more, and the catalyst particles are contained in the aqueous solution at a concentration of 0.4 grams/liter or more and 16 grams/liter or less.

主权项

1. A method for treating an arsenic-containing aqueous solution, comprising:
a step (a) of adding catalyst particles to the aqueous solution containing trivalent arsenic; a step (b) of oxidizing trivalent arsenic by irradiating the aqueous solution with light having a wavelength of 200 nanometers or more and 400 nanometers or less while stirring the catalyst particles in the aqueous solution; and a step (c) of stopping the stirring in the step (b) and separating the catalyst particles from the aqueous solution by sedimentation, wherein each catalyst particle is composed only of a titanium dioxide particle and a zeolite particle, the titanium dioxide particle is adsorbed on an outer surface of the zeolite particle, the zeolite particle has a silica/alumina molar ratio of 10 or more, and the catalyst particles are contained in the aqueous solution at a concentration of 0.4 grams/liter or more and 16 grams/liter or less.