Electrochemical cell, water treatment device provided with same, and operating method for water treatment device

A water treatment device comprising:

• an electrochemical cell having a casing provided with an inflow port of water in a lower portion, and an outflow port of the water in an upper portion, a bipolar membrane laminated body in which two or more bipolar membranes are laminated so as to be opposed, and electrodes disposed such that an anode and a cathode are opposed to sandwich the bipolar membrane laminated body;
• a first water channel connected to the inflow port;
• a second water channel that connects the outflow port and a supply port to which water subjected to water softening treatment by the electrochemical cell is supplied;
• a connection channel that connects the second water channel and the first water channel;
• a tank disposed in the connection channel;
• a channel switch that switches a flow destination of the water flowing in the second water channel to the supply port or the connection channel;
• and
• a pump provided in the connection channel.

An operating method for water treatment device, the water treatment device including:

• an electrochemical cell having a casing provided with an inflow port of water in a lower portion, and an outflow port of the water in an upper portion, a bipolar membrane laminated body in which two or more bipolar membranes are laminated so as to be opposed, and electrodes disposed such that an anode and a cathode are opposed to sandwich the bipolar membrane laminated body;
• a first water channel connected to the inflow port;
• a second water channel that connects the outflow port and a supply port to which water subjected to water softening treatment by the electrochemical cell is supplied;
• a connection channel that connects the second water channel and the first water channel;
• a tank disposed in the connection channel;
• a channel switch that switches a flow destination of the water flowing in the second water channel to the supply port or the connection channel;
• and
• a pump provided in the connection channel, the operating method comprising:
• switching a flow destination of water flowing in the second water channel to the connection channel by the channel switch, which is defined as a step A;
• and
• activating the pump, which is defined as a step B.