Membrane distillation is a promising option for desalination owing to its advantages, but additional studies are still required before drawbacks such as membrane wetting can be resolved. To investigate the effects of organic and inorganic contents in feed solutions on membrane wetting, a lab-scale direct contact membrane distillation system was operated with different compositions of synthetic feed solutions. CaCl₂ and MgSO₄ were added to the feed solutions at different concentrations. Humic acids were injected into the feed solutions as organic additives. The hydrophilicity of humic acids was changed by ozonation with different ozone contact times. Membrane wetting was monitored by measuring the distillate flux and conductivity during operation. As a result, when the concentrations of CaCl₂ and MgSO₄ increased, membrane wetting was increasingly promoted. Once the membrane pores were wetted, salts could pass through from the feed side to the distillate side through the wetted pores, resulting in scale formation even on the distillate side of the membrane after being dried, which was confirmed by scanning electron microscopy. Without ozonation, humic acids were hydrophobic and induced severe membrane fouling, but this retarded the membrane wetting. With ozonation, humic acids were hydrophilic and accelerated the membrane wetting, which was more significant with longer ozone contact times. Hydrophilic ozonated humic acids reduced the liquid entry pressure of the membranes, enhancing the potential for membrane wetting.

中文翻译：

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直接接触式膜蒸馏过程中进料组成与膜润湿之间的相关性

膜蒸馏由于其优点而成为脱盐的有前途的选择，但是在解决诸如膜润湿之类的缺点之前，仍需要进行额外的研究。为了研究进料溶液中有机和无机含量对膜润湿的影响，使用了实验室规模的直接接触式膜蒸馏系统，对合成进料溶液的不同成分进行了操作。CaCl ₂和MgSO ₄将其以不同浓度添加到进料溶液中。腐殖酸作为有机添加剂注入进料溶液中。腐殖酸的亲水性通过臭氧化与不同的臭氧接触时间而改变。通过测量操作过程中的馏分通量和电导率来监测膜的润湿性。结果，当CaCl ₂和MgSO ₄的浓度膜润湿增加，膜的润湿性越来越高。一旦膜孔被润湿，盐就可以通过被润湿的孔从进料侧流到馏出物侧，甚至在干燥后的膜的馏出物侧上也形成水垢，这通过扫描电子显微镜得到了证实。如果不进行臭氧处理，则腐殖酸是疏水性的，会导致严重的膜污染，但这会阻碍膜的润湿。进行臭氧化处理后，腐殖酸具有亲水性，并加速了膜的润湿，而臭氧接触时间越长，腐殖酸的作用就越大。亲水的臭氧化腐殖酸降低了膜的液体进入压力，增加了膜润湿的可能性。