本研究以恆壓過濾系統，採透析過濾及濃縮程序兩種操作方法過濾玻尿酸溶液，探討在不同pH值(3、5、7、13)、攪拌速度(0、100、300、500 rpm)及進料濃度(0.25、0.5、1、2 kg/m3)下，對濾速、濃度極化、阻隔率及過濾阻力之變化。 在低進料濃度(0.25 kg/m3)及高攪拌速度(500 rpm)下，當操作壓力大於150 kPa時，已接近極限濾速區域。在溶液pH=3時，HA分子較接近為球狀粒子，堆積形態緊密，濾速相對較低。濃度高時，因溶液黏度較高會產生較大的過濾阻力使得濾速較低；由過濾阻力之分析，發現濃度極化阻力遠大於薄膜阻力及結垢阻力，加入攪拌可有效降低濃度極化阻力而提升濾速。濃縮程序中，在攪拌速度為500 rpm下，可將HA濃度從0.5 kg/m3濃縮至1.5 kg/m3，隨著槽內濃度及黏度上升濾速降低，於濃縮後期因薄膜表面膠層形成，濃度極化阻力急劇上升。 This study investigated the diafiltration and concentration of HA solution in a dead-end stirred cell. The flux behavior, HA rejection and filtration resistance were discussed under various operating parameters such as pH value (3, 5, 7 and 13), stirred rate (0, 100, 300 and 500 rpm) and feed concentration (0.25, 0.5, 1 and 2 kg/m3). At low feed concentration (0.25 kg/m3) and high stirred rate (500 rpm), the limiting flux region was reached as the operation pressure exceeded 150 kPa. For pH = 3, the permeate was relatively low due to the fact that the HA molecule is close to a spheroid particle and results in a compact polarization layer. The filtration resistance increased with the increase of feed concentration due to the increment of feed viscosity; By measuring the filtration resistances, it is noted that the concentration polarization resistance is significantly larger than the membrane resistance or the fouling resistance. The addition of stirred rate can effectively disturb the concentration polarization layer and enhance the permeate flux. At 500 rpm, the 0.5 kg/m3 HA solution was concentrated to 1.5 kg/m3. The permeate flux decreased with the increases of solution concentration and viscosity in the stirred cell. Moreover, the filtration resistance increased hugely at the late stage of concentration due to the formation of gel layer on the membrane surface.
