WATER TREATMENT DEVICE

PROBLEM TO BE SOLVED: To provide a water treatment device enhancing performance for water purification treatment. SOLUTION: This device is provided with a tank 3 for housing water 1 to be treated, granular photocatalyst bodies 21 added into the tank 3, a light source 19 for irradiating the photocatalyst bodies 21 with light, capturing members 13, 15 for the photocatalyst bodies 21 provided in flow paths 5, 7 of the water 1 to be treated and communicating with the tank 3, and liquid transfer means 9, 11 provided in the flow paths 5, 7, and a flow direction of the water 1 to be treated in the tank 3 is changed by alternately operating the liquid transfer means 9, 11. Thus, since the flow direction of the water 1 to be treated flowing through the collection members 13, 15 changes and inverts, the photocatalyst bodies 21 captured with the capturing members 13, 15 and the photocatalyst bodies 21 staying in the vicinity of the capturing members 13, 15 can be re-dispersed into the water 1 to be treated in the tank 3, and the light from the light source 19 can be efficiently received and the photocatalyst activity is enhanced.