Abstract: A water softening device includes an electrolysis device, a first circulation flow path and a second circulation flow path, a first sensor, a second sensor, and a controller, wherein the controller controls the electrolysis device to execute a first mode in which the alkaline water is allowed to flow through the first circulation flow path and the acidic water is allowed to flow through the second circulation flow path, and a second mode in which the acidic water is allowed to flow through the first circulation flow path (8A) and the alkaline water is allowed to flow through the second circulation flow path, and controls to stop electrolysis by the electrolysis device based on a detection value of the first sensor or the second sensor in the first mode and the second mode.

Abstract: The water treatment device according to the present disclosure includes: an electrochemical cell having electrodes including a positive electrode and a negative electrode, and a bipolar membrane; a tank; a power supply configured to apply power to the electrodes; a water circulation flow path having at least the tank and the electrochemical cell and through which water circulates; a circulation device configured to circulate water in the water circulation flow path; a raw water supply path configured to supply raw water to the water circulation flow path; and a control device. In performing water softening treatment in the electrochemical cell where power is applied to the electrodes so as to remove ions from raw water and soft water is produced, the control device drives the circulation device so as to circulate water in the water circulation flow path.

Abstract: An electrochemical cell according to the present disclosure includes a casing provided with an inflow port and an outflow port, a bipolar membrane laminated body in which two or more bipolar membranes are laminated so as to be opposed, electrodes disposed so as to sandwich the bipolar membrane laminated body, and a first diffusion member disposed between the inflow port and the bipolar membrane laminated body, and provided with through holes communicating between the inflow port and the bipolar membrane laminated body. The first diffusion member is formed such that each of the through holes provided in a peripheral edge portion has a larger opening area than an opening area of the through holes provided in a central portion. This can uniformize a flow of water, so that water treatment can be efficiently executed.

Abstract: The water treatment device according to the present disclosure includes: an electrochemical cell having electrodes including a positive electrode and a negative electrode, and a bipolar membrane; a tank; a power supply configured to apply power to the electrodes; a water circulation flow path having at least the tank and the electrochemical cell and through which water circulates; a circulation device configured to circulate water in the water circulation flow path; a raw water supply path configured to supply raw water to the water circulation flow path; and a control device. In performing water softening treatment in the electrochemical cell where power is applied to the electrodes so as to remove ions from raw water and soft water is produced, the control device drives the circulation device so as to circulate water in the water circulation flow path.

Abstract: An electrochemical cell according to the present disclosure includes a casing provided with an inflow port and an outflow port, a bipolar membrane laminated body in which two or more bipolar membranes are laminated so as to be opposed, electrodes disposed so as to sandwich the bipolar membrane laminated body, and a first diffusion member disposed between the inflow port and the bipolar membrane laminated body, and provided with through holes communicating between the inflow port and the bipolar membrane laminated body. The first diffusion member is formed such that each of the through holes provided in a peripheral edge portion has a larger opening area than an opening area of the through holes provided in a central portion. This can uniformize a flow of water, so that water treatment can be efficiently executed.