The purification performance of a forward osmosis (FO) membrane on natural organic matter (NOM) contained in real surface water by was investigated systematically. FO could reject the natural dissolved organic matter (DOM) effectively with removal efficiencies of approximately 99.0%. When the natural water samples (e.g., raw surface water) had lower fouling tendencies, the active layer facing the draw solution (AL-facing-DS mode) provided a higher water flux than that in the alternative membrane orientation because the isoflux point occurred later in the process. It was found that the concentration of calcium ions had a more severe effect on decreasing the fouling flux of the FO membrane than that of the organic foulant. Furthermore, the concentrated feed solution had a more significant effect on the fouling flux decline of the natural DOM containing more small molecules than natural DOM containing more macromolecules. Additionally, the fouling that occurred in the AL-facing-DS orientation was compensated by the reduced internal concentration polarization (ICP) level based on the occurrence of the critical compensation point. It was also revealed that the permeation drag caused by the water flux and the chemical interactions induced by the feed solution pH and the calcium ion concentration played a significant role in the adsorption of small natural DOM molecules in the porous structure of the FO membrane. Based on the analysis of the interfacial free energies, the interactions between the natural DOM and the surface of the support layer dominated the initial fouling of the FO membrane, while subsequent fouling was controlled by the interaction between the approaching DOM molecules and the already adsorbed DOM.

系统研究了正渗透膜对真实地表水中所含天然有机物的净化性能。FO可以有效去除自然溶解的有机物（DOM），去除效率约为99.0％。当天然水样品（例如原地面水）具有较低的结垢倾向时，面向汲取溶液的活性层（面向AL的DS模式）提供的水通量高于替代膜取向时的通量，因为等通点的发生较晚正在进行中。已发现，钙离子的浓度对降低FO膜的结垢通量的影响比有机污垢剂更严重。此外，浓缩的进料溶液对包含更多小分子的天然DOM的污垢通量下降的影响要大于包含更多大分子的天然DOM的结垢通量下降的影响。此外，基于临界补偿点的出现，通过降低的内部浓度极化（ICP）级别可以补偿在面向AL的DS方向上发生的结垢。还揭示了由水通量引起的渗透阻力以及由进料溶液pH和钙离子浓度引起的化学相互作用在FO膜的多孔结构中的小的天然DOM分子的吸附中起重要作用。根据界面自由能的分析，