WATER TREATMENT APPARATUS AND ITS METHOD

PROBLEM TO BE SOLVED: To provide a water treatment apparatus and its method, capable of performing an immersion-type filtration stably at a low cost, even when the quality of raw water fluctuates.SOLUTION: The water treatment apparatus 100 comprises: a water tank 3 for receiving raw water; a membrane module 4 stored and immersed in the water tank 3 for filtration treatment to make filtrate water; a drain channel 10 capable of draining water retained in the water tank 3; a flow regulating device P2 capable of regulating the flow rate of the water drained from the drain channel 10; a water quality sensor 2 for measuring the quality of the raw water; and a controlling unit 20 for controlling the flow regulating device P2 based on the measurement by the water quality sensor 2. The water treatment method comprises filtration treatment of raw water by utilizing the difference of water level while draining the water retained in the water tank 3 to increase the flow rate of the retained water drained from the drain channel 10 when an amount of a suspended substance contained in the raw water increases.SELECTED DRAWING: Figure 1 【課題】原水の水質が変動したとしても、浸漬型の膜濾過を低コストで安定的に行える水処理装置及び水処理方法を提供する。【解決手段】水処理装置１００は、原水が導入される水槽３と、水槽３に水中に浸漬された状態で保持され、原水を濾過処理して濾過水を作る膜モジュール４と、水槽３に滞留する滞留水を排水可能な排水路１０と、排水路１０を通じて排水される滞留水の流量を調整可能な流量調整装置Ｐ２と、原水の水質を計測する水質センサ２と、水質センサ２による計測に基いて流量調整装置Ｐ２を制御する制御部２０と、を備える。水処理方法は、水槽３に滞留する滞留水を排水しつつ水位差を利用して原水を濾過処理し、原水に含まれている濁質の量が増加したとき、排水路１０を通じて排水される滞留水の量を増加させるものである。【選択図】図１