| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a water treatment system capable of suppressing deposition of scale on the membrane surface and fouling without increasing a load of a pretreatment unit. <P>SOLUTION: The water treatment system includes a pretreatment unit 3, a membrane separation device 7 that separates pretreatment water W2 into permeated water W5 and thickened water W6, a storage tank 9, a water quality detecting means 14, a water level detecting means 18, a pressurizing pump 5, an inverter 6, drain valves 11 to 13, a control part 10 for drive that controls the inverter 6 so that the flow rate of the permeated water W5 becomes a first target flow rate value or a second target flow rate value smaller than the first target flow rate value, and a control part 10 for flow rate that, when the water quality detected with the water quality detecting means 14 exceeds a permissible water quality value, and (i) if the storage tank 9 has less than a reference water level, the drain valves 11 to 13 are controlled so that the flow rate is set to the first target flow rate value and the thickened water W6 becomes a first discharge flow rate, and (ii) if the storage tank 9 has the reference water level or more, the drain valves 11 to 13 are controlled so that the flow rate value is set to the second target flow rate value and the thickened water W6 becomes the second discharge flow rate. <P>COPYRIGHT: (C)2013,JPO&INPIT |
