Performance of forward (direct) osmosis process: membrane structure and transport phenomenon.
Performance of forward (direct) osmosis process: membrane structure and transport phenomenon.
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DOI：
10.1021/es0519177
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发表时间：
2006-02
影响因子：
11.4
通讯作者：
H. Ng;Wanling Tang;W. Wong
中科院分区：
文献类型：
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作者：
H. Ng;Wanling Tang;W. Wong
利用实验室装置研究了正向(直接)渗透(FO)过程的性能，以阐明膜结构和取向对水通量的影响。以碳酸氢铵、葡萄糖和果糖为拉伸液，对两种类型的反渗透膜和一种反渗透膜进行了试验，从盐水料液中提取水。在相同的实验条件下，FO膜能够获得比RO膜更高的水通量，同时保持了97%以上的高盐截留率。提高操作温度增加了FO过程中的水通量。为了考察膜取向对水通量的影响，对FO膜进行了正反向(面向料液的致密选择层)和正反向(面向料液的致密选择层)试验。对FO过程中的传输现象提出了解释，解释了FO膜在垂直方向上使用时，由于内部浓差极化较小，性能更好的观察结果。研究表明，理想的FO膜应该由一层薄而致密的选择性层组成，没有任何松散的织物支撑层。
The performance of a forward (direct) osmosis (FO) process was investigated using a laboratory-scale unit to elucidate the effect of membrane structure and orientation on waterflux. Two types of RO membrane and a FO membrane were tested using ammonium bicarbonate, glucose, and fructose as the draw solution to extract water from a saline feed solution. The FO membrane was able to achieve higher water flux than the RO membranes under the same experimental conditions while maintaining high salt rejection of greater than 97%. Increasing operating temperature increased the water flux in FO process. To investigate the effect of membrane orientation on water flux, the FO membrane was tested normally (dense selective layer facing draw solution) and reversely (dense selective layer facing feed solution). Explanations on transport phenomenon in FO process were proposed which explain the observation that the FO membrane, when used in the normal orientation, performed better due to lesser internal concentration polarization. This study suggests that an ideal FO membrane should consist of a thin dense selective layer without any loose fabric support layer.