A method of removing arsenic from water by using a reactor that is provided with
a fluidized bed of carriers is disclosed. An arsenic-containing influent is mixed
in the reactor with a sulfide aqueous solution or metallic salt aqueous solution
at a predetermined pH, thereby resulting in formation of crystals of arsenic sulfides
or arsenic acid metal salts. The arsenic contained in the influent is thus removed
by crystallization. An effluent with a reduced arsenic content is discharged from
the reactor. The carriers, on which the crystals are formed, are periodically removed
from the reactor which is replenished with fresh carriers immediately after.