Acidic treatment liquid processing apparatus, acidic treatment liquid processing method, surface treatment system, and surface treatment method

An acidic treatment liquid processing method, comprising:

• passing an acidic treatment liquid containing a dichromate ion and a metal cation into a first chamber separated from a second chamber by a diaphragm permeable to a metal cation, and passing an acid aqueous solution into the second chamber;
• applying a voltage while using a first electrode disposed in the first chamber as an anode and a second electrode disposed in the second chamber as a cathode to move a metal cation in the acidic treatment liquid to the acid aqueous solution through the diaphragm;
• and
• measuring, during applying a voltage to the first electrode and the second electrode, a temperature of the acidic solution in the second chamber using a sensor,
• wherein, in response to a determination that the diaphragm breaks based on a measurement result of the sensor, the applying of the voltage and the passing of the acidic treatment liquid are stopped.