Membrane distillation (MD) is a thermally induced membrane separation process that utilizes vapor pressure variance to permeate the more volatile constituent, typically water as vapor, across a hydrophobic membrane and rejects the less volatile components of the feed. Permeate flux decline, membrane fouling, and wetting are some serious challenges faced in MD operations. Thus, in recent years, various studies have been carried out on the modification of these MD membranes by incorporating nanomaterials to overcome these challenges and significantly improve the performance of these membranes. This review provides a comprehensive evaluation of the incorporation of new generation nanomaterials such as quantum dots, metalloids and metal oxide-based nanoparticles, metal organic frameworks (MOFs), and carbon-based nanomaterials in the MD membrane. The desired characteristics of the membrane for MD operations, such as a higher liquid entry pressure (LEPw), permeability, porosity, hydrophobicity, chemical stability, thermal conductivity, and mechanical strength, have been thoroughly discussed. Additionally, methodologies adopted for the incorporation of nanomaterials in these membranes, including surface grafting, plasma polymerization, interfacial polymerization, dip coating, and the efficacy of these modified membranes in various MD operations along with their applications are addressed. Further, the current challenges in modifying MD membranes using nanomaterials along with prominent future aspects have been systematically elaborated.

The activated sludge models (ASMs) commonly used by the International Water Association (IWA) task group are based on chemical oxygen demand (COD) fractionations. However, the proper evaluation of COD fractions, which is crucial for modelling and especially oxygen uptake rate (OUR) predictions, is still under debate. The biodegradation of particulate COD is initiated by the hydrolysis process, which is an integral part of an ASM. This concept has remained in use for over 30 years. The aim of this study was to verify an alternative, more complex, modified (Activated Sludge Model No 2d) ASM2d for modelling the OUR variations and novel procedure for the estimation of a particulate COD fraction through the implementation of the GPS-X software (Hydromantis Environmental Software Solutions, Inc., Hamilton, ON, Canada) in advanced computer simulations. In comparison to the original ASM2d, the modified model more accurately predicted the OUR behavior of real settled wastewater (SWW) samples and SWW after coagulation–flocculation (C–F). The mean absolute relative deviations (MARDs) in OUR were 11.3–29.5% and 18.9–45.8% (original ASM2d) vs. 9.7–15.8% and 11.8–30.3% (modified ASM2d) for the SWW and the C–F samples, respectively. Moreover, the impact of the COD fraction forms and molecules size on the hydrolysis process rate was developed by integrated OUR batch tests in activated sludge modelling.

Over the past decades, numerous materials have emerged as promising amenities for the fabrication of novel membranes. The current study gives insight into a modest and effective method to fabricate a crosslinked poly‐vinylidene fluoride‐co‐hexafluoropropylene membrane with better mechanical properties and permeability for desalination. Poly‐vinylidene fluoride‐co‐hexafluoropropylene membrane was grafted with crosslinked collagen to enhance direct contact membrane distillation used for desalination. Stiffness, rigidity and mechanical properties of the membrane were intensified by incorporating collagen (extracted from eggshells) into the membrane matrix, with glutaraldehyde crosslinkers. Furthermore, to improve water vapor diffusion, immobilized carbon nanofibers (CNF) were integrated in the membrane, casted via phase inversion technique with an optimized controlled approach. The permeate flux of CNF incorporated membrane was as high as 8 LMH, 18% higher than the unmodified poly‐vinylidene fluoride‐co‐hexafluoropropylene membrane at 60 °C, besides minimal salt leakage. The properties of the modified membrane were characterized from its contact angle, morphological structure, surface roughness, dynamic mechanical properties, and water flux. The overall performance of the modified membranes was better than the virgin membranes. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48021.