| 摘要 |
<P>PROBLEM TO BE SOLVED: To stably supply produced water of high purity while suppressing oxidative deterioration of a reverse osmosis membrane (a RO membrane), to promptly devise a countermeasure even when oxidative deterioration occurs and further to attain energy saving. <P>SOLUTION: Raw water pumped up from a raw water pump 1 is supplied to an active carbon filtering apparatus 2 to remove free chlorine contained in the raw water. Then the raw water from which free chlorine is removed is supplied to a water softening apparatus 3 to soften the raw water to hardness of 5 mg CaCO<SB>3</SB>/L or less and thus treated water is produced and is supplied to a RO apparatus 4. In the RO apparatus 4, operating pressure of 0.5 MPas or less is applied to the RO membrane 12a composed of an ultra low pressure membrane to carry out membrane filtration separation to water filtrate (product water) of high purity and condensed water. Further a first silica concentration measuring apparatus 10a and a second silica concentration measuring apparatus 10b calculate a silica removing ratio ϕ and proceeding of oxidative deterioration of the RO membrane 12a is monitored. <P>COPYRIGHT: (C)2010,JPO&INPIT |
