This metal containing waste water treatment method introduces a metal
containing waste water from above into a submerged membrane separation
tank 1 in which a reaction section 2, a submerged membrane section 3
having a submerged membrane 5 and a precipitation section 4 are arranged
in order from top to bottom, causes a reaction by adding a pH adjuster to
the reaction section 2, subsequently separates water from metal by the
submerged membrane 5 of the submerged membrane section 3 and subsequently
precipitates and concentrates the metal in the precipitation section 4.
As described above, according to this treatment method, the pH adjuster
is added to the reaction section 2, and therefore, solid-liquid
separation can be effected by the submerged membrane 5 with a hydroxide
formed. Moreover, the metal can be precipitated and concentrated by the
action of gravity without using energy in the precipitation section 4.