Abstract Pressure retarded osmosis (PRO) is an innovative technique to yield osmotic energy. Nevertheless, the PRO performance is exacerbated by the severe membrane fouling occurring within the porous support. It is a potential alternative for sustainable power harvesting to change the membrane orientation from active layer facing draw solution (AL−DS) or PRO mode to active layer facing feed solution (AL−FS) or FO mode for a low-fouling propensity. A novel integral PRO hollow fiber membrane was developed in this work by phase inversion and followed with a facile cross-linking post-treatment. The structure and properties of the resultant membrane were systematically investigated using a series of characterization protocols. The PRO performance of the membrane was studied under various hydraulic pressures at the AL−FS orientation. The results reveal that the substrate with sponge-like structure and relatively dense inner surface can better withstand high pressure in PRO process. Two steps of cross-linking endowed the membrane with a smaller pore size on the outer surface that exhibits high rejection against various inorganic salts. The novel integral membrane can achieve a stable power density output around 4.3 W m−2 at 12 ~ 13 bar hydraulic pressure, using a real wastewater reverse osmosis (RO) retentate and 1.0 M sodium chloride as the feed and draw stream, correspondingly. This result demonstrates that the PRO operation in the AL−FS orientation (FO mode) offers a significant advantage over the AL−DS orientation (PRO mode) by eliminating the pretreatment of the feed water or/and other measures associated with membrane fouling control in the PRO mode. To implement the PRO operation with the AL−FS orientation, developing a robust membrane with an integral structure is critical. The newly developed integral hollow fiber membrane via chemical cross-linking presents the potential for PRO operation in the AL−FS orientation.

中文翻译：

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具有化学交联的整体中空纤维膜，用于压力延迟渗透，以面向进料溶液的活性层取向操作

摘要 压力延迟渗透 (PRO) 是一种产生渗透能的创新技术。然而，PRO 性能会因多孔载体内发生的严重膜污染而恶化。将膜取向从面向活性层的汲取溶液 (AL-DS) 或 PRO 模式更改为面向活性层的进料溶液 (AL-FS) 或 FO 模式，以实现低污染倾向，这是可持续能量收集的潜在替代方案。在这项工作中，通过相转化开发了一种新型一体式 PRO 中空纤维膜，然后进行了简单的交联后处理。使用一系列表征方案系统地研究了所得膜的结构和性质。在 AL-FS 方向的各种液压压力下研究了膜的 PRO 性能。结果表明，具有海绵状结构和相对致密的内表面的基材在PRO工艺中可以更好地承受高压。两步交联使膜在外表面具有较小的孔径，对各种无机盐表现出很高的截留率。新型整体膜可以在 12 ~ 13 bar 水压下实现大约 4.3 W m-2 的稳定功率密度输出，相应地使用真正的废水反渗透 (RO) 截留物和 1.0 M 氯化钠作为进料和抽取流。该结果表明，在 AL-FS 方向（FO 模式）下的 PRO 操作通过消除进料水的预处理或/和其他与膜污染控制相关的措施，提供了优于 AL-DS 方向（PRO 模式）的显着优势。 PRO 模式。为了实现具有 AL-FS 方向的 PRO 操作，开发具有整体结构的坚固膜至关重要。新开发的通过化学交联的整体中空纤维膜在 AL-FS 方向具有 PRO 操作的潜力。