本篇論文主要在探討逆流型透析器中伴隨超過濾或回流以提高質量傳送之操作。在理論的推導過程中為了數學上的簡便我們假設超過濾通量並未隨著質量傳送而遞減。由本次研究結果可知在透析伴隨超過濾情況下對於質量傳送速率會有明顯地的提升，值得一提的是當溶質質傳係數較小時，增加超過濾操作會大量提高質量傳送速率。由進料體積流率來看，提高透餘相的體積流率會比提高透析相的體積流率還要更好。最後我們發現提高超過濾通量以及進料體積流率可使溶質與溶劑分離效率更佳的良好。由於數學推導過程的假設，其研究結果可能僅適用於輕微的濃度極化現象及輕微的透膜壓差遞減之情形。 在逆流型交流式透析器伴隨內回流操作中，我們假設流體於通道橫切面的速度和溶質濃度為均一。由本次研究結果可知在透析伴隨內回流情況下對於質量傳送速率也會有明顯地的提升。也因為多了回流裝置使得溶質進料體積流率會比無回流裝置的進料體積流率還大，如此一來便可降低裝置內的質傳阻力。由整理出的圖表可看出提高回流比與提高進料體積流率和進料濃度可大幅增加質傳效率。 The effect of application of either ultrafiltration or recycle operation to dialysis in countercurrently rectangular membrane modules was investigated. For the dialysis coupled with the application of ultrafiltration operation in a countercurrrently parallel-flow device, the assumption of uniform ultrafiltration flux was made 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 increased with increasing ultrafiltration flux, as well as with increasing the volumetric flow rates. Furthermore, increasing the volumetric flow rate in retentate phases is more beneficial to mass transfer than increasing in dialysate phase. For dialysis with internal recycling operation in countercurrently cross-flow device, the uniform velocities and concentrations in the cross sections of flow channels were assumed. 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.