Seawater membrane distillation (SWMD) is a promising separation technology due to its ability to operate as a stand-alone desalination unit operation. This paper reviews approaches to improve laboratory-to-pilot-scale MD performance, which comprise operational strategies, module design, and specifically tailored membranes. A detailed comparison of SWMD and sea water reverse osmosis is presented to further analyze the critical shortcomings of SWMD. The unique features of SWMD, namely the ability to operate with extremely high salt rejection and at extreme feed concentration, highlight the SWMD potential to be operated under zero liquid discharge (ZLD) conditions, which results in the production of high-purity water and simultaneous salt recovery, as well as the elimination of the brine disposal cost. However, technical challenges, such as thermal energy requirements, inefficient heat transfer and integration, low water recovery factors, and lack of studies on real-case valuable-salt recovery, are impeding the commercialization of ZLD SWMD. This review highlights the possibility of applying selected strategies to push forward ZLD SWMD commercialization. Suggestions are projected to include intermittent removal of valuable salts, in-depth study on the robustness of novel membranes, module and configuration, utilization of a low-cost heat exchanger, and capital cost reduction in a renewable-energy-integrated SWMD plant.

中文翻译：

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海水膜蒸馏 (SWMD) 向独立零液体排放 (ZLD) 淡化的进展

海水膜蒸馏 (SWMD) 是一种很有前途的分离技术，因为它能够作为独立的脱盐装置运行。本文回顾了提高实验室到中试规模 MD 性能的方法，其中包括操作策略、模块设计和专门定制的膜。给出了 SWMD 和海水反渗透的详细比较，以进一步分析 SWMD 的关键缺点。SWMD 的独特功能，即能够在极高的脱盐率和极高的进料浓度下运行，突出了 SWMD 在零液体排放 (ZLD) 条件下运行的潜力，从而产生高纯度水和同时盐回收，以及消除盐水处理成本。然而，技术挑战，诸如热能需求、低效率的传热和集成、低水回收率以及缺乏对真实案例有价盐回收的研究，正在阻碍 ZLD SWMD 的商业化。本综述强调了应用选定策略来推动 ZLD SWMD 商业化的可能性。预计建议包括间歇性去除有价值的盐，深入研究新型膜、模块和配置的稳健性，利用低成本热交换器，以及降低可再生能源集成 SWMD 工厂的资本成本。本综述强调了应用选定策略来推动 ZLD SWMD 商业化的可能性。预计建议包括间歇性去除有价值的盐，深入研究新型膜、模块和配置的稳健性，利用低成本热交换器，以及降低可再生能源集成 SWMD 工厂的资本成本。本综述强调了应用选定策略来推动 ZLD SWMD 商业化的可能性。预计建议包括间歇性去除有价值的盐，深入研究新型膜、模块和配置的稳健性，利用低成本热交换器，以及降低可再生能源集成 SWMD 工厂的资本成本。