STUDY ON DESALINATION PROCESS USING LIQUID MEMBRANE

为了建立新型的生化产品下游处理脱盐系统，本工作开发了以下两种使用液膜系统的装置，并对它们的特性进行了实验研究。在脱盐装置的设计中，重要的是使两种W/O乳状液接触，以用进料溶液提取阳离子和阴离子，防止乳状液彼此接触。装置（1）：将两种W/O乳状液分别通过的中空纤维放入包括进料溶液的搅拌槽中。装置（2）：将两种W/O型乳状液的搅拌槽用料液能通过而各乳状液不能通过的隔板隔开，该装置（1）由于难以将乳液相和进料溶液之间的界面保持在中空纤维的孔中，和光纤的外部压力。同时，在装置（2）中，发现用含氟聚合物涂覆并以5 mm的间隔堆叠的两个不锈钢网可用作分离乳液的隔板。乳状液与隔板的碰撞速率是控制乳状液泄漏的重要因素之一，通过调节乳状液的分散条件和乳状液与料液的体积比，可以实现仅离子的迁移。

For the establishment of the novel desalination system in the downstream processing of biochemical products, the following two apparatus using the liquid membrane system were developed in the present work and their characteristics were investigated experimentally. In the design of the apparatus for the desalination, it is important to contact the two kinds of W/O emulsions to extract the cation and anion with the feed solution, preventing the emulsions from contacting each other.Apparatus (1) : The hollow fibers, through which the two kinds of W/O emulsions were separately passed, were put in the stirred cell including the feed solution.Apparatus (2) : The stirred cells including the two kinds of W/O emulsions respectively were separated by the partition through which the feed solution can pass but each emulsion can not.As a result, the apparatus (1) was not available for the desalination system because it is difficult to keep the interface between the emulsion phase and the feed solution in the pore of the hollow fiber adjusting the inner and outer pressures of the fiber. While, in the apparatu (2), it was found that the two stainless steel meshes which were coated by the fluorine-contained polymers and piled at intervals of 5 mm are useful as the partition to separate the emulsions. Also, the collision rate of emulsions to the partition is one of the important factors to control the leakage of the emulsions, and we can accomplish to transfer only the ions by adjusting the dispersion conditions of emulsions and the volume ratio of emultions to that of the feed solution.