Water treatment device and operation method for same

An operation method for a water treatment device comprising:

• an electrolysis device that generates alkaline water and acidic water by electrolysis and has an electrode whose polarity can be switched;
• a first circulation flow path and a second circulation flow path that are circulation flow paths connected to the electrolysis device and are capable of alternately passing the alkaline water and the acidic water generated by the electrolysis device through;
• a water storage tank that stores treated water generated by the electrolysis device;
• and a control device,
• the control device executing at least two electrolysis steps and a polarity switching step of switching the polarity of the electrode of the electrolysis device between the electrolysis steps executed consecutively,
• wherein the electrolysis step includes the steps of:
• supplying raw water to the electrolysis device;
• generating alkaline water and acidic water by electrolysis of raw water and causing the alkaline water and the acidic water to pass through the first circulation flow path or the second circulation flow path;
• and
• delivering the alkaline water and the acidic water that are generated to the water storage tank and storing the alkaline water and the acidic water in the water storage tank as treated water, and
• the control device performs control, in the polarity switching step, to cause the acidic water or the treated water generated by the electrolysis device to pass through the electrolysis device.