Two-step ultrafiltration of rhamnolipids using PSU-g-PEG membrane
- 作者：Xuwei Longa ; Qin Menga ; mengq@zju.edu.cn ; Ruyi Shaa ; Qilong Huanga ; Guoliang Zhangb ; guoliangz@zjut.edu.cn
- 关键词：UF-1 ; the first ultrafiltration step ; UF-2 ; the second ultrafiltration step ; UF ; ultrafiltration ; PSU ; polysulfone ; PEG ; poly-ethylene glycol ; PSU-g-PEG ; polysulfone-g-poly-ethylene glycol ; BSA ; bovine serum albumin ; BCA ; bicinchoninic acid ; R (%) ; reject
- 刊名：Journal of Membrane Science
- 出版年：2012
- 期刊代码：55_03767388
- 类别：ch
- 出版时间：1 August, 2012
- 卷：409-410
- 期：Complete
- 页码：105-112
- 文件大小：1572 K
摘要
The practical application of two-step ultrafiltration in industry has been limited by severe membrane fouling and the need for a large ethanol dose. To develop an antifouling membrane in two-step ultrafiltration of rhamnolipids from cell-free culture broth, this study evaluated the possibility of using polysulfone-g-polyethylene glycol (PSU-g-PEG), a polysulfone (PSU) hollow-fiber membrane surface modified by polyethylene glycol (PEG). Compared with the commercially available ultrafiltration hollow-fiber membrane PSU, PSU-g-PEG sustained a higher efficiency and maintained better antifouling property in operation. After further optimization of operation conditions (pH and ethanol concentration), over 98%of rhamnolipids were retained in the first ultrafiltration step by the PSU-g-PEG membrane and 87%of the retained rhamnolipids permeated the membrane in the second ultrafiltration. Moreover, the water flux of a treated membrane could be restored to 93%of its initial flux by a regular flush and could be completely recovered by a subsequent overnight immersion. Interestingly, the PSU-g-PEG membrane sustained its high separation efficiency and good antifouling property after extremely long operation (7 h) and seven consecutive operations. These results indicate that the PSU-g-PEG membrane has a large potential for industrial application in recovering rhamnolipids from cell-free culture broth.