Membrane distillation (MD) that can sustainably recover freshwater until salt crystallization is a potential candidate for hypersaline wastewater treatment. However, a huge challenge for MD is membrane scaling, which sharply decreases membrane flux and salts rejection efficiency. This study reported an ion-nucleating competition cooperated with commercial antiscalants to mitigate membrane scaling. Results showed that the superhydrophobic PVDF (SH-PVDF) membrane could effectively delay the gypsum nucleation on the slippery membrane surface owing to the increased membrane surface roughness, but scaling inevitably occurs on the membrane surface in the supersaturated condition. Introducing the foreign ions such as one-component Na⁺ or Mg²⁺ and two-component Na⁺/Mg²⁺ mixture can improve the gypsum solubility and delay gypsum nucleation for mitigating membrane scaling. Besides, the synergistic combination of commercial antiscalant and ion-nucleating competition is extraordinarily effective in retarding membrane scaling and preventing membrane pore wetting, achieving a high-water recovery of ~85 % and robust salt rejection of ~100 %. The mechanisms of ion-nucleating competition cooperated with antiscalants were also discussed with the help of characterizations. This work provided a novel ion-nucleating competition in collaboration with antiscalants for hypersaline wastewater management, which is important for MD to be applied in near-zero liquid discharge (ZLD).

可以可持续地回收淡水直到盐结晶的膜蒸馏 (MD) 是高盐废水处理的潜在候选者。然而，MD 面临的一个巨大挑战是膜结垢，这会急剧降低膜通量和盐截留效率。该研究报告了一种离子成核竞争与商业阻垢剂合作以减轻膜结垢。结果表明，超疏水PVDF（SH-PVDF）膜由于增加了膜表面粗糙度，可以有效延缓滑膜表面的石膏成核，但在过饱和条件下，膜表面不可避免地会产生结垢。引入外来离子如单组分Na ⁺或Mg ²⁺和双组分Na ⁺/Mg ²⁺混合物可以提高石膏溶解度并延迟石膏成核以减轻膜结垢。此外，商业阻垢剂和离子成核竞争的协同组合在延缓膜结垢和防止膜孔润湿方面非常有效，实现了约 85% 的高水回收率和约 100% 的强脱盐率。还借助表征讨论了离子成核竞争与阻垢剂的协同作用机制。这项工作与阻垢剂合作提供了一种新的离子成核竞争，用于高盐废水管理，这对于将 MD 应用于近零液体排放 (ZLD) 非常重要。