在本論文中，對超過濾和內回流操作在順流型薄膜膜組中進行了研究。對於應用超過濾操作在順流型平板薄膜透析器中，研究中為了數學演算的方便，假設了均一的超過濾通量，所得的結果可能僅能適用於輕微的濃度極化和透膜壓差的現象。應用超過濾操作在質量傳送之中，可以達到相當大的改善效果，特別是那些有較低質傳係數的系統中。當增加超過濾通量或增加體積流率，分離效率也會明顯的增加。此外，對質量傳送而言，增加透餘相中的體積流率比增加透析相的體積流率更有效益。 而順並流型裝置伴有內回流操作系統中，假設流體渠道截面中的速度和濃度皆均一。和無回流的裝置相比，有內回流操作的透析器有較好的質傳效果，蓋因其增加了流體速度，導致質傳阻力減少。提高效率伴隨著回流比增加，特別是較大體積流率和入口濃度的操作系統。 The applications of either ultrafiltration or recycle operation to dialysis in cocurrently rectangular membrane modules was investigated. For the dialysis with the application of ultrafiltration operation in a cocurrrently parallel-flow device, uniform ultrafiltration flux was assumed for operation with slight concentration polarization and declination of transmembrane pressure. Considerable improvement in mass transfer is achievable if the operation of ultrafiltration is applied, especially for the system with low mass transfer coefficient.The enhancement in separation efficiency is significantly in increased with increasing ultrafiltration flux, as well as with increasing the volumetric flow rates. Moreover, increasing the volumetric flow rate in retentate phases is more beneficial to mass transfer than increasing in dialysate phase. For dialysis with the application of internal recycling operation in cocurrently parallel flow device, the assumptions made that both uniform velocities and concentrations in the cross sections of flow channels were uniform. In contrast to a device without reflux, considerable mass transfer is achievable if the dialyzers are operated with internal recycling, which provides an increase in fluid velocity, resulting in a reduction of mass-transfer resistance. The improvement increases with reflux ratio, especially for large flow rate and feed concentration.