Hassan A. Arafat

Khalifa University | KU · Center for Membrane and Advanced Water Technology

Membrane distillation (MD) has shown potential as a means of desalination and water purification. As a thermally driven membrane technology which runs at relatively low pressure, which can withstand high salinity feed streams, and which is potentially more resistant to fouling, MD could be used for desalination where reverse osmosis is not a good o...

Economic evaluation was carried out to understand the main contributors to water production cost in solar-powered membrane distillation (SP-MD) systems. Three SP-MD systems (Direct Contact (DCMD), Air Gap (AGMD), and Vacuum (VMD)) were modeled and economically analyzed. A parametric study was conducted on the AGMD, the most frequently used SP-MD co...

Polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) membranes were prepared via the electrospinning method. Three sets of mats, with different fiber diameters and physical properties, were obtained by varying polymer concentration from 10 to 15 wt%. Membranes were formed by hot pressing the prepared mats to fuse the fibers. As prepared mats w...

Street littering is considered an important environmental health issue in the Middle East. This problem is growing steadily and is attracting great concerns within the communities. The purpose of this paper, which focuses on Nablus district (Palestinian Territory), is to measure the perception and opinion of residents toward littering, in addition...

The development of sustainable materials for energy is a critical challenge in the pursuit of a circular economy. This study presents an innovative approach for recycling lithium-ion batteries (LIBs) using a novel, sustainable deep eutectic solvent (DES) composed of glycine, ascorbic acid, and water. This natural, chloride-free ternary DES leverage...

In the flourishing field of materials science and engineering, ionic liquids (ILs) stand out for their advantageous features, unique tunable properties, and environmentally friendly attributes, making them ideal candidates for various applications. However, the enormous diversity of ILs presents a challenge that has traditionally been addressed thr...

Feed spacers are incorporated in membrane modules to enhance fluid mixing, thereby enhancing membrane flux. Previous experimental work showed that triply periodic minimal surfaces (TPMS)-based spacers induce significant improvements in membrane distillation (MD) performance, which was attributed to the suppression of membrane boundary layer, reduci...

The membrane research community has witnessed a significant research growth on feed spacers since 2010, both in quantity and scope. Increasingly novel spacer geometries and spacer chemistries are being reported in literature to tackle key challenges facing membrane processes, including concentration polarization, energy consumption, low flux, and f...

The motivation of this computational research is to comprehensively analyze the performance of the air gap membrane distillation (AGMD) process by varying the membrane porosity at different inlet feed temperatures (Tfeed) in counter-current and co-current flow regimes. This computational study also includes the comparative study of different membra...

Renewable energy-enabled desalination systems are crucial for solving the global water scarcity challenges in an environmentally friendly manner. In this work, we report an air gap membrane distillation (AGMD) process that utilizes polyvinylidene fluoride (PVDF) membranes blended with a photothermally active and relatively inexpensive activated car...

In this work, novel mussel-inspired polydopamine nanoparticles functionalized with ionic liquid (PDA-IL) were synthesized via one step oxidative polymerization and Schiff-base addition reaction using dopamine and ionic liquid (3-aminopropylammonium acetate). The synthesized polydopamine-ionic liquid (PDA-IL) was utilized as an efficient adsorbent i...

In this work, a quaternized polydopamine (QSiPD) nanohybrid was synthesized via condensation reaction between the silicon hydroxyl moieties of the hydrolyzed QSiP and hydroxyl moieties of polydopamine (PDA) and applied for the first time as a single additive to Poly(ether sulfone) (PES) ultrafiltration (UF) and loose nanofiltration (NF) membranes m...

Lithium-ion batteries (LIBs) wide usage constitutes a disposal threat to the environment. As a result, several laws are being introduced to encourage the recycling of this waste, particularly, in lithium recovery. Deep eutectic solvent (DES) has been reported as an efficient solvent in valuable metal recovery from spent LIB. However, efficient deep...

The impact of feed spacer design on membrane fouling mechanism in ultrafiltration (UF) process under constant flux mode was systematically investigated. Thecombined intermediate pore blocking and cake filtration model was employed,coupled with experimental crossflow UF experiments of dextran and sodium alginate (SA) in aqueous feed solutions. Filtr...

Predicting the performance of a full-scale direct contact membrane distillation (DCMD) module based on experimental lab-scale results is rather difficult, since the DCMD performance is dependent on many different process parameters. Hence, there is a need for a methodology to perform DCMD system up-scaling based on lab-scale experimental results. I...

In this research, choline chloride/malonic acid (ChCl-MA) deep eutectic solvent (DES) supported onto silica (SiO2) nanoparticles were incorporated into polyimide (PI) membrane precursor solution to develop novel composite mixed matrix membranes via phase inversion to improve their hydrophilicity, porosity, mean pore size, surface roughness, and wat...

A novel high-performance hybrid ultrafiltration (UF) membrane was fabricated by blending polydopamine-coated graphene oxide (PDGO) nanosheets with sulfonated poly(ether sulfone) (SPES) via phase inversion method and tested for the removal of natural organic matter (humic acid; HA) from aqueous solution. The PDGO nanosheets were synthesized via self...

In this study, a new quaternized polydopamine anchored reduced graphene oxide (QSiPD-rGO) nanohybrid was prepared through a one-step mussel-inspired tailoring of GO using a quaternized silica precursor and dopamine. The QSiPD-rGO was applied for the first time as a nanofiller, at a significant loading rate of up to 8 wt%, to manufacture positively...

New genres of ionic liquids and deep eutectic solvents (DES) have recently emerged as eco-efficient "designer's solvents". Herein, we report the liquification of the water soluble diol 2,2,4-trimehtyl-1,3-pentanediol (TMPD) into a novel hydrophobic DES with thymol or menthol, where the intrinsic supercooling properties of the constituents yielded e...

Per-/poly-fluoroalkyl substances (PFAS) are an emerging class of environmental contaminants used as additives to either enhance the thermo-chemical stability of products or alter the properties of surfaces. PFAS are amphiphilic molecules, composed of fluoro-alkyl chains terminated by specialized functional groups such as carboxylic, sulphonic acids...

In this study, process enhancements achieved by the use of 3D printed feed spacers based on triply periodic minimal surfaces (TPMS) were comparatively assessed using the two most common membrane distillation (MD) configurations: air gap (AGMD) and direct contact (DCMD). The MD performance was assessed based on the impact of spacer design (TPMS vs....

A novel 3D printed photocatalytic feed spacer was developed for use in membrane-based water and wastewater filtration systems. The spacer fulfilled two new functions; degradation of membrane-permeating pollutants in the feed and membrane cleaning, in addition to its basic role as membrane support. The spacer, designed based on a triply periodic min...

Surface modification of feed spacers rather than membranes may hold more merit as an antiscaling strategy in membrane distillation (MD), as it avoids compromising the functionality of MD membrane. In this work, an antiscaling polyamide 3D printed spacer was developed for MD. The surface of the printed spacer was coated with fluorinated silica (FS)...

The globally recurring droughts, day-zero scenarios and the lack of resiliency of traditional water resources to climate change has led to an increased dependence on desalination as a more robust alternative. However, the adoption and proliferation of desalination are strongly affected by a plethora of often overlooked socio-political factors. Thes...

The removal of heavy metal ions from industrial wastewater is essential as they pose serious threats to human health and the environment. In this study, novel poly(vinylidene fluoride) (PVDF)-alpha-zirconium phosphate (PVDF-α-ZrP) mixed matrix membranes (MMM) were prepared via the phase inversion method. Membranes with different α-ZrP nanoparticles...

The unprecedented performance of fouling resistant, high flux and high rejection hybrid ultrafiltration polysulfone membranes with charge tunable channels using functionalized polymer chains grafted graphene oxide (SPK-g-GO) nanosheets for natural organic matter removal from aqueous feed is herein reported. The novel SPK-g-GO nanosheets were first...

The unprecedented performance of fouling resistant, high flux and high rejection hybrid ultrafiltration polysulfone membranes with charge tunable channels using functionalized polymer chains grafted graphene oxide (SPK-g-GO) nanosheets for natural organic matter removal from aqueous feed is herein reported. The novel SPK-g-GO nanosheets were first...

In this study, the impacts of three feed spacer design parameters; thickness, porosity and architecture, on the cleaning efficiency of ultrafiltration (UF) membranes were studied, both in backwash and relaxation cleaning modes, using sodium alginate solution dosed with CaCl2 as the process feed. Both commercial, net-type spacers and 3D-printed spac...

Static mixers are frequently used in water treatment applications, for example as inline coagulators. A desired geometry of a static mixer is one that results in low mixing energy and high mixing efficiency. Triply periodic minimal surfaces (TPMS) are architectures which are described mathematically such that the mean curvature is zero at any point...

Thin film deposition (TFD) allows for precise tuning of the chemical and physical properties of a membrane to improve performance, including the selectivity, flux, chemical resistance, and antifouling and antimicrobial properties. TFD techniques have a unique advantage over other traditional surface modification methods (e.g., grafting) vis-à-vis t...

In this work, four novel hydrophobic deep eutectic solvents (DES) were prepared from a combination of menthol (Men) or thymol (Thy) as hydrogen bond acceptors (HBA) with 1-decanol (Dec) or 2-methyl-2,4-pentanediol (MPD) as hydrogen bond donors (HBD), for the extraction of boron from aqueous solutions. The DESs were characterized in terms of their p...

One solution to the water scarcity problem is membrane-based desalination technologies. However, these technologies still need further improvement. Modeling tools are helpful in this regard to investigate and enhance the transport phenomena through the membrane or within the module flow channels. Various simulation tools, which depend on specific t...

Lignin forms a recalcitrant structure in lignocellulosic biomass and hence huge amount of enzymes are required for disintegrating it into their subsequent components, like glucose and other by-products. Thus, the pretreatment is an ineluctable step in the bioethanol scheme for the delignification of biomass and also the recovery of lignin, an emer...

Wetting phenomenon inside the pore is a significant obstacle hindering membrane distillation (MD) from being fully industrialized. Herein, a new equation is provided for the users, using the combination of computational fluid dynamics (CFD) and genetic programming (GP) tools for estimation of liquid entry pressure (LEP), a parameter closely related...

In this work, a new protocol was developed for creating charge-tuned, hydrophilic hybrid ultrafiltration (UF) membranes with high flux, rejection rate and fouling resistance. The membranes were fabricated using a combination of sulfonated poly(ether sulfone) (SPES) and aminated graphene (GO-SiO2-NH2) nanohybrid via the non-solvent induced phase sep...

The effects of select system parameters on the performance of direct contact membrane distillation (DCMD), in terms of permeate flux (J) and temperature polarization coefficient (TPC), were investigated and compared for flat-sheet (FS) and hollow-fiber (HF) modules. Three-dimensional (3D) computational fluid dynamics (CFD) models were developed and...

In this study, the performance of novel 3D printed spacers was investigated for scaling control in direct contact membrane distillation (DCMD). The spacers, designed as triply periodic minimal surfaces (TPMS), were tested under calcium sulfate scaling conditions, with brine recycling leading to continuous feed concentration increase. The DCMD exper...

3D printing offers the flexibility to achieve favorable spacer geometrical modification. The role of 3D printed spacers for organic fouling mitigation in direct contact membrane distillation (DCMD) is evaluated. Compared to a commercial spacer, the design of 3D printed triply periodic minimal surfaces spacers (Gyroid and tCLP) - varying filament th...

The critical factors and interactions which affect the module-level performance of permeate gap membrane distillation (PGMD) were investigated. A three-dimensional computational fluid dynamics (CFD) model was developed for the PGMD configuration, and the model was validated using experimental data. The realizable k- ε turbulence model was applied f...

In this work, a universal integrated framework to assess the sustainability of desalination technologies was developed. The framework integrates the techno-economic, environmental and social factors of sustainability using a combination of multi-criteria decision analysis techniques, such as the analytic hierarchy process, swing and weighted summat...

This study reports on the enhancement of direct contact membrane distillation (DCMD) performance by incorporating magnetite nanoparticles (NP) in polyvinylidene fluoride (PVDF) membranes to render the membrane bulk hydrophilic while maintaining a hydrophobic top surface. Hansen solubility parameters (HSP) were first calculated to assess the affinit...

Conventional water resources in many regions are insufficient to meet the water needs of growing populations, thus reuse is gaining acceptance as a method of water supply augmentation. Recent advancements in membrane technology have allowed for the reclamation of municipal wastewater for the production of drinking water, i.e., potable reuse. Althou...

An ideal feed spacer balances high flux and low pressure drop while minimizing fouling. In this work, several feed spacer with complex triply periodic minimal surface (TPMS) geometries were designed and fabricated using additive manufacturing (AM) processing. AM technology was employed to vary the voidage and directionality of the spacers. The fabr...

A filter element comprises a membrane layer; and a feed spacer on the membrane layer, wherein the feed spacer comprises a plurality of unit cells arranged in three dimensions, wherein each of the plurality of unit cells comprises a cavity defined by a triply periodic minimal surface, and wherein the cavities of the plurality of unit cells are inter...

Two polyvinylidene fluoride (PVDF) membrane modification approaches, i.e. PVP modification and sulfonation, were applied and investigated in this study to produce fouling resistant membrane for microalgae filtration. Both methods were able to alter membrane surface to become more hydrophilic. However, clean water permeance increased only for the PV...

A two-dimensional computational fluid dynamics (CFD) model was developed and validated to estimate the liquid entry pressure (LEP) of hydrophobic membranes used for membrane distillation (MD). The volume of fluid (VOF) approach was employed to model the pore wetting process at pore-scale. As a result, the water/air interface could be identified at...

Polyvinylidene fluoride (PVDF) membranes play a key role in several industrial applications. Tuning the properties of these membranes enables a sharp selectivity for the target application. The goal of this work is to chemically bind carbon nanotubes (CNT) onto the surface of PVDF membranes. Such membranes can open the door for a variety of new app...

In this chapter, the main problems associated with brine discharge, specifically its impact on the marine environment, are discussed. The use of different brine disposal methods alongside the environmental concerns associated with each respective method is presented. Modeling brine discharge using existing software tools are briefly discussed. Brin...

The accelerated awareness of water's strategic value for national security has placed desalination in the heart of the food-water-energy nexus. In this chapter, an introduction is made to high-level sustainability appraisal of desalination from an ecological, economic, and social points of view drawing on the classical definition of sustainability....

Full sustainability appraisal of all desalination options is necessary to determine which technologies perform the best in regards to environment, economic and social aspects. It is widely recognized and accepted that sustainability assessments should take a life cycle approach, taking into account all relevant sustainability aspects. Therefore, an...

Reverse osmosis (RO) by polymeric membranes is known to be among the successful technologies for brackish and seawater desalination. For the development of these polymeric RO membranes, two different techniques have been used – the phase inversion method for asymmetric membranes, such as cellulose acetate membrane and the interfacial polymerization...

A method comprising a two-step alkali/acid treatment of poly (vinylidene fluoride) (PVDF) polymer is developed for the fabrication of flat-sheet PVDF membranes functionalized with labile hydroxyl groups. This method involves the application of a short-duration modification in alkali medium (5% KOH). Extensive characterizations were performed on the...

Polyvinylidene fluoride (PVDF) membranes play a key role in several industrial applications due to their favorable properties, including their high chemical stability. Tuning the properties of PVDF membranes enables a sharp selectivity for the target application. One of the direct methods to achieve this goal is the selective activation of PVDF mem...

Ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]oAc) was employed for the pretreatment of sugarcane bagasse (SCB) and extraction of lignin, a potentially valuable by-product of the biofuel industry. Response surface methodology based on central composite design was exploited and thereby an empirical model, exhibiting a coefficient of determ...

The fabrication of polyvinylidene fluoride (PVDF) membranes was studied using chitosan as a hydrophilic additive for flux enhancement and stability. Chitosan (CS) was blended with PVDF at 0.5, 1.0, 1.5, 2.0 and 2.5% (w/w) concentration, to prepare mixed matrix membrane using the phase inversion method. CS presence within the polymer matrix was conf...

Polyvinylideneflouride (PVDF) has considerable usage in different disciplines including sensors, piezoelectric materials, biomedical application as well as membranes. In this paper, facile and effective method for the activation of inert PVDF surface and molecular grafting of this material is presented. Mild concentration of piranha reagent used to...

The critical failure mode for membrane distillation (MD) desalination is wetting through the pores of the hydrophobic membrane, which allows the saline solution to leak through and contaminate the permeate. The standard practice for reversing membrane wetting is to dry out the membrane for several hours before resuming the desalination process. An...

This study explored the impact of hydrophobic fumed silica (FS) particles as an inorganic additive in the preparation of polyvinylidenefluoride (PVDF) membranes using the phase inversion technique. PVDF membranes were prepared by varying the percentage of FS additive (0-5 wt.%) in the dope solution. Hansen solubility parameters (HSPs) were calculat...

Hollow fiber membranes consisting of polyethersulfone (PES) reformed with high proportions of –OH, aryl-N and alkyl-F groups in nonsolvent additives were compared for the removal of residual Cr (VI), COD, and bacteria from treated wastewater effluent by studying the underlying functional and molecular interactions during dope preparation and phase...

Research on membrane distillation (MD) experienced a slow growth from the 1970s through 90s but has gained revived interest recently. Despite recent developments, MD still has to overcome several hurdles to pave its path to successful commercialization. This article presents a systematic map review of all research publications available in the Scie...

Storing desalinated water within a strategic aquifer storage and recovery system has been identified as a potential cost-effective solution for the Gulf Council Cooperation (GCC) countries. In this study, we investigated a wind-driven reverse osmosis (RO) scheme to create fresh water for ASR. The ongoing Liwa ASR project in the United Arab Emirates...

Booming population, higher standard of living, and growing industrialization continue to exert a demand for energy. The continuous and unlimited use of fossil fuels to meet the growing energy demand would deplete the finite oil reserves, and have detrimental environmental impacts causing global warming and climate change. Given the present circumst...

Sizing of large scale pervaporation units from experimental data requires mathematical models which can predict the pervaporation process performance adequately. In this work, a modeling approach is reported with a semi-empirical flux model regressed over experimental flux data measured at lab scale. The regression approach generates a temperature...

Polyvinylidene fluoride (PVDF) is a popular polymer material for making membranes for several applications, including membrane distillation (MD), via the phase inversion process. Non-solvent-induced phase separation (NIPS) and vapor-induced phase separation (VIPS) are applied to achieve a porous PVDF membrane with low mass-transfer resistance and h...