著者

長谷川 裕晃 大津 里実

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集B編 (ISSN:18848346)

巻号頁・発行日

vol.77, no.783, pp.2049-2057, 2011 (Released:2011-11-25)

参考文献数

20

被引用文献数

1

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The reverse osmosis (RO) method is a method obtaining the fresh water by using semi permeable RO membrane. However, the RO method has to give continuous operation at high pressure in seawater desalination plants. In the present study, in order to improve the efficiency of RO desalination under low pressure conditions, the water treatment system is proposed by using microbubbles in salt water disposal. Microbubbles are very small air bubbles with diameters of the order of less than several tens microns, and our proposed microbuble generator was developed in our previous study. The RO desalination efficiency can be improved by microbubble generation in salt water in contrast to the method with no microbubbles, and the efficiency of desalination is significantly improved by microbubbles with a high electrical potential. The effect of the microbubbles on the rate of osmosis was also investigated by measurements of the electric conductivity and the shrinkage rate of microbubbles. The electrical conductivity of salt water decreases with increasing the electrical property of the gas-water interface (ζ- potential) of microbubbles. Furthermore, microbubbles with a high electrical potential of high number density in salt water can exist in salt water because the rising velocity and the shrinkage rate of microbubbles become smaller with increasing the high electrical potential of microbubbles.