Mat Nawi Normi Izati, Bilad Muhammad Roil, Zolkhiflee Nurazrina, Nordin Nik Abdul Hadi, Lau Woei Jye, Narkkun Thanitporn, Faungnawakij Kajornsak, Arahman Nasrul, Mahlia Teuku Meurah Indra
Chemical Engineering Department, Universiti Teknologi PETRONAS, Seri Iskandar, Perak 32610, Malaysia.
Ad Advanced Membrane Technology Research Centre (AMTEC), Universiti Teknologi Malaysia, Skudai 81310, Johor, Malaysia.
Polymers (Basel). 2019 May 13;11(5):865. doi: 10.3390/polym11050865.
Membrane distillation (MD) is an attractive technology for desalination, mainly because its performance that is almost independent of feed solute concentration as opposed to the reverse osmosis process. However, its widespread application is still limited by the low water flux, low wetting resistance and high scaling vulnerability. This study focuses on addressing those limitations by developing a novel corrugated polyvinylidene difluoride (PVDF) membrane via an improved imprinting technique for MD. Corrugations on the membrane surface are designed to offer an effective surface area and at the same time act as a turbulence promoter to induce hydrodynamic by reducing temperature polarization. Results show that imprinting of spacer could help to induce surface corrugation. Pore defect could be minimized by employing a dual layer membrane. In short term run experiment, the corrugated membrane shows a flux of 23.1 Lmh and a salt rejection of >99%, higher than the referenced flat membrane (flux of 18.0 Lmh and similar rejection). The flux advantage can be ascribed by the larger effective surface area of the membrane coupled with larger pore size. The flux advantage could be maintained in the long-term operation of 50 h at a value of 8.6 Lmh. However, the flux performance slightly deteriorates over time mainly due to wetting and scaling. An attempt to overcome this limitation should be a focus of the future study, especially by exploring the role of cross-flow velocity in combination with the corrugated surface in inducing local mixing and enhancing system performance.
膜蒸馏（MD）是一种颇具吸引力的海水淡化技术，主要是因为其性能几乎与进料溶质浓度无关，这与反渗透过程不同。然而，其广泛应用仍受到低水通量、低抗润湿性和高结垢易发性的限制。本研究致力于通过一种改进的压印技术开发一种新型的波纹聚偏氟乙烯（PVDF）膜来解决这些限制，该技术用于膜蒸馏。膜表面的波纹设计用于提供有效的表面积，同时作为湍流促进剂，通过降低温度极化来诱导流体动力学。结果表明，间隔物的压印有助于诱导表面波纹。采用双层膜可将孔隙缺陷降至最低。在短期运行实验中，波纹膜的通量为23.1 Lmh，脱盐率>99%，高于参考平板膜（通量为18.0 Lmh，脱盐率相似）。通量优势可归因于膜的有效表面积更大以及孔径更大。在50小时的长期运行中，通量优势可维持在8.6 Lmh。然而，通量性能会随着时间略有下降，主要是由于润湿性和结垢。克服这一限制的尝试应成为未来研究的重点，特别是通过探索错流速度与波纹表面相结合在诱导局部混合和提高系统性能方面的作用。
