Abdelrazeq Haneen, Khraisheh Majeda, Hassan Mohammad K
Department of Chemical Engineering, College of Engineering, Qatar University, Doha P.O. Box 2713, Qatar.
Center for Advanced Materials, Qatar University, Doha P.O. Box 2713, Qatar.
Membranes (Basel). 2022 Apr 14;12(4):424. doi: 10.3390/membranes12040424.
Membrane distillation (MD) is an attractive separation process for wastewater treatment and desalination. There are continuing challenges in implementing MD technologies at a large industrial scale. This work attempts to investigate the desalination performance of a pilot-scale direct contact membrane distillation (DCMD) system using synthetic thermal brine mimicking industrial wastewater in the Gulf Cooperation Council (GCC). A commercial polyethylene membrane was used in all tests in the DCMD pilot unit. Long-term performance exhibited up to 95.6% salt rejection rates using highly saline feed (75,500 ppm) and 98% using moderate saline feed (25,200 ppm). The results include the characterization of the membrane surface evolution during the tests, the fouling determination, and the assessment of the energy consumption. The fouling effect of the polyethylene membrane was studied using Humic acid (HA) as the feed for the whole DCMD pilot unit. An optimum specific thermal energy consumption (STEC) reduction of 10% was achieved with a high flux recovery ratio of 95% after 100 h of DCMD pilot operation. At fixed operating conditions for feed inlet temperature of 70 °C, a distillate inlet temperature of 20 °C, with flowrates of 70 l/h for both streams, the correlations were as high as 0.919 between the pure water flux and water contact angle, and 0.963 between the pure water flux and salt rejection, respectively. The current pilot unit study provides better insight into existing thermal desalination plants with an emphasis on specific energy consumption (SEC). The results of this study may pave the way for the commercialization of such filtration technology at a larger scale in global communities.
膜蒸馏（MD）是一种用于废水处理和海水淡化的有吸引力的分离工艺。在大规模工业应用中实施MD技术仍面临持续挑战。这项工作旨在研究中试规模的直接接触式膜蒸馏（DCMD）系统处理模拟海湾合作委员会（GCC）工业废水的合成热盐水的脱盐性能。DCMD中试装置的所有测试均使用了商用聚乙烯膜。长期运行结果表明，使用高盐度进料（75,500 ppm）时，脱盐率高达95.6%，使用中盐度进料（25,200 ppm）时，脱盐率为98%。结果包括测试过程中膜表面演变的表征、污垢测定以及能耗评估。以腐殖酸（HA）作为整个DCMD中试装置的进料，研究了聚乙烯膜的污垢效应。在DCMD中试运行100小时后，实现了10%的最佳比热能消耗（STEC）降低，通量恢复率高达95%。在进料入口温度为70°C、馏出物入口温度为20°C、两股水流流速均为70 l/h的固定操作条件下，纯水通量与水接触角之间的相关性高达0.919，纯水通量与脱盐率之间的相关性高达0.963。当前的中试装置研究更深入地了解了现有的热法海水淡化厂，重点关注比能耗（SEC）。本研究结果可能为这种过滤技术在全球范围内更大规模的商业化铺平道路。
