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COVID-19 infections and severe acute respiratory syndrome (SARS) have caused an unprecedented health crisis across the globe with numerous deaths, as well as causing a tremendous economic crash worldwide.

Metal–organic frameworks (MOFs) are widely explored for advances in hybrid membranes because of their bonding and fondness in polymers.

Membrane technologies have been successfully developed as the separation and purification processes, such as desalination, wastewater treatment, gas separation and so forth. It is known that membrane pore size and pore size distribution (PSD) are the factors by which membrane performance is significantly affected. In this study, a novel mathematical model is presented to evaluate the PSD. Although the new model is based on the bubble gas transport method, it is different from the conventional approach since this model starts from the assumption of a distribution function, typically Gaussian normal distribution, for the PSD, and a flow rate versus pressure line is drawn theoretically based on the assumed PDS. Then, the mean pore size and standard deviation of the PSD are optimized by the best fit of the theoretical line to the experimental one using the nonlinear regression analysis. A unique feature of the proposed model is that fewer experimental data points are necessary to find the optimal PSD. In addition, experiments with the dry membrane are no longer required. The PSDs estimated by this model for three commercial membranes were compared with those obtained by the conventional method, and an excellent agreement was observed.

Membrane distillation (MD) is an emerging technology for the desalination of brines. In some cases, liquid penetrates into the pores of the membrane, causing pore wetting. MD’s commercialization is hindered largely due to the occurrence of pore wetting phenomena since it results in the reduction of flux and/or permeate quality. Hence, it is of crucial importance for MD to prevent pore wetting from occurring. In this paper, the methods of detecting pore wetting and the membrane parameters related to this phenomenon are reviewed and possible sources of MD pore wetting occurrence are identified. Moreover, the methods to prepare membranes specifically designed for the mitigation of membrane wetting, such as the design of membrane materials, membrane surface modification, preparation of nanocomposite membranes by the addition of nanoparticles, dual-layered membranes, and membranes with a re-entrant structure are discussed. Finally, process-based approach for wetting mitigation, mainly by the pretreatment of the feed solution, is elucidated, and models for wetting phenomena are also outlined. Thus, attempts are made in this review to discuss all aspects of the pore wetting of MD membranes.

Usually, membrane performances are primarily motivated by the surface morphology. The morphological structure of the thin-film composite (TFC) membrane presents new potential applications for forward osmosis (FO) activities. In this review, the effect of different layered structural modifications on the activities of the TFC-FO flat sheet membranes was reviewed, highlighting several membranes layered frameworks along with the literature evidence. Also, we thoroughly investigated how the morphological properties including surface porosity, pore size, thickness and roughness influence the performance of FO membranes. This review paper concluded that the porosity, tortuosity, membrane thickness, surface roughness, water flux, salt rejection and reverse salt fluxes were altered by different layered structural modifications on the FO membranes. In addition, layer-by-layer (LbL) surface modified TFC-FO membranes helps to (i) prevent the direct contact of the skin and support layers, (ii) minimized the water transport resistance and increased the membrane selectivity, (iii) improved the water flux and solute rejection and (iv) reduced the structural parameter (S-value) and the internal concentration polarization (ICP).