Nidal Hilal

New York University Abu Dhabi · NYUAD Water Research Center

Over the last decades, the tightening of water quality regulations and the increased attention given to trace contaminants in water has been favouring the emergence of novel treatment technologies in order to upgrade or improve conventional water treatment processes. This review surveys recent studies on using combined ion exchange (IX) and pressur...

This paper presents an overview on recent developments in surface modification of polymer membranes for reduction of their fouling with biocolloids and organic colloids in pressure driven membrane processes. First, colloidal interactions such as London-van der Waals, electrical, hydration, hydrophobic, steric forces and membrane surface properties...

Ceramic membranes are gaining importance in several mainstream membrane applications. Their high chemical and thermal resistance stability make them ideal candidates for oil/water separation, dye rejections, in dairy production, catalyst recovery and in treating a variety of wastewater effluents. Although ceramic microfiltration and ultrafiltration...

Feed spacers are an important component of membrane‐based filtration systems as they promote turbulence and mass transfer during the filtration process—thereby, reducing the membrane fouling and improving the flux. Whereas spacers are used as a separate component in conjunction with membranes, herein, we demonstrate that membrane‐integrated spacers...

Despite water being critical for human survival, its uneven distribution, and exposure to countless sources of pollution make water shortages increasingly urgent. Membrane technology offers an efficient solution for alleviating the water shortage impact. The selectivity and permeability of membranes can be improved by incorporating additives of dif...

Brine, in the form of seawater, salt lakes and geothermal water, holds massive amounts of valuable minerals. Among the variety of metallic and non-metallic elements that are recovered from brine at varying scales, Lithium (Li) has received immense interest in recent years due to its exponentially rising demand. Concentrated brine, which is the by-p...

Electrospinning is a versatile technique for the fabrication of nanofibrous, nanostructured composite membranes for a large number of applications. This mini-review focuses on electrospun membranes for various MD configurations. We provide a background to the electrospinning process, recent developments, and the potential of the electrospinning tec...

Membrane fouling is one of the challenging issues surrounding membrane‐based separation. Here in, we demonstrate direct 3D printing of electrically conductive interdigitated spacer on an ultrafiltration membrane for membrane cleaning and chlorination via periodic electrolysis. The spacers were 3D printed on the membrane surface via material extrusi...

Much research has been carried out in recent years to investigate the use of nanomaterials as fillers in polymeric nanofiltration membranes, to improve water transport and fouling resistance whilst preserving, where possible, selectivity. This review paper considers the background to this research, including membrane fabrication and incorporation o...

Nanofiltration (NF) membrane has been applied for the treatment of wastewater owing to its unique features such as higher selectivity towards divalent/polyvalent ions while allowing permeation for monovalent ions and small molecules of less than 100 Da. Thus, the use of NF in wastewater treatment is promising for water recycling, reuse, and recover...

Air gap membrane distillation (AGMD) is a low-temperature separation process applied commonly to desalination of (hyper)saline feeds. The low energy efficiency of heating the bulk feed solution to drive vapor transport in MD must be addressed through novel materials and techniques. In this work, we introduce the concept of intermittent electrical h...

The implementation of membrane surface modification to enhance the performance of membrane-based separation has become a favored strategy due to its promise to address the trade-off between water permeability and salt rejection as well as to improve the durability of the membranes. Tremendous work has been committed to modifying polymeric membranes...

Membrane Distillation (MD) is a membrane-based, temperature-driven water reclamation process. While research emphasis has been largely on membrane design, upscaling of MD has prompted advancements in energy-efficient module design and configurations. Apart from the four conventional configurations, researchers have come up with novel MD membrane mo...

The saline wastewater from various sources including agriculture and industrial activities, appears to have high salt concentration, organic content and other pollutants which can harm the environment. Thus, saline waste-water treatment has become one of the major concerns in many countries. Membrane technology offers great potential in saline wast...

Surface modification of membranes is an effective approach for imparting unique characteristics and additional functionalities to the membranes. Chemical grafting is a commonly used membrane modification technique due to its versatility in tailoring and optimizing the membrane surface with desired functionalities. Various types of polymers can be p...

Inorganic membranes hold great potential for various mainstream applications such as in wastewater treatment, drug manufacturing, food and beverage production, and dairy purification. There are numerous commercially available ceramic membranes which possess high corrosion resistance, high strength, and good heat resistance. However, these membranes...

Zeolites, in the form of monolithic and well-defined structures, offer great opportunity as potential adsorbents to remediate various environmental pollutants. In this work, zeolite-Y structures were fabricated via 3D printing technique and their potential was demonstrated for removing toxic heavy metals from wastewater. Using a lab-scale column-ty...

Water scarcity is a grand challenge that requires continuous exploration of new desalination technologies in order to augment the global supply of fresh water. In this context, membrane distillation (MD) is a promising technology that operates based on a thermal gradient to transfer vapor molecules across a porous hydrophobic membrane. Lack of suit...

Fertilizer-drawn forward osmosis (FDFO) is a potential alternative to recover and reuse water and nutrients from agricultural wastewater, such as palm oil mill effluent that consists of 95% water and is rich in nutrients. This study investigated the potential of commercial fertilizers as draw solution (DS) in FDFO to treat anaerobic palm oil mill e...

Fouling is major concern in several industries involving separation of heavy oil components such as crude and motor oils. In this work, a novel free-standing, conductive ceramic membrane, made from nanozeolite and carbon nanostructures (CNS) was fabricated. Various nano-zeolite: CNS ratios were studied. The membranes were tested for oil/water separ...

Ultrafiltration (UF) and nanofiltration (NF) membranes have attracted great research interest to treat dye wastewaters. However, UF membranes suffer from low dye rejection and NF membrane have low salt recovery. There is a tradeoff between the dye rejection and salt recovery in the UF and NF membranes. A novel membrane is required for dye rejection...

Water scarcity is a global issue that needs to be urgently addressed to alleviate its adverse impacts on social and economic development. Desalination has been touted as an attractive alternative that can sustainably provide freshwater, particularly when there is no better option to augment water supplies. Tremendous research innovations and evolut...

Emerging technologies present many new possibilities for diversifying the desalination industry, which is currently dominated by thermal desalination, and reverse osmosis. In this review, we highlight recent developments in emerging desalination technologies, focusing on those nearing commercialization i.e. forward osmosis and membrane distillation...

The shortage of clean water sources and increase of demand for fresh water have become as major global challenges not only in industries but also inhuman life. Meanwhile, membrane technology has been extensively noticed due to high separation efficiency, energy-saving and environmentally-friendly characteristic. So, development of new membrane is a...

Unmatched flexibility in terms of material selection, design and scalability, along with gradually decreasing cost, has led 3D printing to gain significant attention in various water treatment and desalination applications. In desalination, 3D printing has been applied to improving the energy efficiency of existing technologies. For thermal desalin...

Water constitutes one of the basic necessities of life. Around 71% of the Earth is covered by water, however, not all of it is readily available as fresh water for daily consumption. Fresh water scarcity is a chronic issue which poses a threat to all living things on Earth. Seawater, as a natural resource abundantly available all around the world,...

Membrane distillation (MD) is a useful technology for water desalination possible at low temperatures using inexpensive membranes offering high salt rejection. Therefore, in the present study, economically and eco-friendly Saudi red clay, tetraethyl orthosilicate, ammonia, and sodium alginate powder as a binder were used to fabricate a ceramic memb...

Membrane fouling in water treatment is a major drawback in membrane-based separation processes. In this work, periodic electrolytic membrane cleaning was used for the first time on ceramic-based electrically conductive membranes. Highly conductive nano zeolite/CNS, hydrophilic microfiltration membranes were fabricated through vacuum filtration, wit...

Nano zeolite-Y ultrafiltration (UF) membrane, with mean pore diameter of 28 nm was fabricated using a simple isostatic pressing technique. Zeolite-Y has preferential water pathways and a unique 3-D microporous structure. The zeolite-Y used in this study has an Al to Si (Al/Si) ratio of 0.07 which renders the membrane superhydrophilic with complete...

With limited resources as a driver, the search for novel materials for improved desalination processes has been a major component of water research in recent years. Graphene and its derivatives are one such promising material. Graphene is a 2D material, which exhibits remarkable strength and durability, has a very high specific surface area, is eas...

Pressure retarded osmosis (PRO) has gained attention due to its use as a salinity gradient energy-generating membrane process. This process can convert difference in salinity between two streams into energy as it allows water transport through a semi-permeable membrane against the application of hydraulic pressure. This review provides a comprehens...

Forward osmosis (FO) has been recognized as the preferred alternative membrane-based separation technology for conventional water treatment technologies due to its high energy efficiency and promising separation performances. FO has been widely explored in the fields of wastewater treatment, desalination, food industry and bio-products, and energy...

Nowadays, integrated microfiltration (MF) membrane systems treatment is becoming widely popular due to its feasibility, process reliability, commercial availability, modularity, relative insensitivity in case of wastewater of various industrial sources as well as raw water treatment and lower operating costs. The well thought out, designed and impl...

Membrane distillation (MD) lags behind other desalination processes such as reverse osmosis due to relatively high energy consumption. Heating in membrane distillation forms a significant component of total energy consumption. This review provides an overview of the various conventional and non-conventional heating methods used in the MD process, f...

Desalinated water is not suitable for direct use as it is prone to corrosion and has adverse effects on human health and the environment. Desalinated water is slightly acidic, lacks minerals and cannot be used un-buffered, thus making remineralization an important component downstream of desalination. We systematically review remineralization requi...

Forward osmosis technology is one of the most rapidly developing processes of desalination and water treatment. The transport of boron in forward osmosis (FO) using various FO membranes was investigated in this study. Three specific membranes — an FTS H2O™ membrane, a PSU membrane and an Aquaporin Inside™ membrane — were applied to study the impact...

Further reduction in energy consumption is an attractive prospect for both well-established technologies such as reverse osmosis and electrodialysis, and for emerging desalination technologies struggling to reach commercialization. One way of reducing energy consumption and meeting target water demands is by playing on the strengths of two or more...

The world is facing the third coronavirus caused pandemic in less than twenty years. The SARS-CoV-2 virus not only affects the human respiratory system, but also the gastrointestinal tract. The virus has been found in human feces, in sewage and in wastewater treatment plants. It has the potential to become a panzootic disease, as it is now proven t...

Recently, forward osmosis (FO) has attracted a great deal of attention in desalination and wastewater treatment. Nevertheless, there are several critical challenges such as the need for new advances in designing membranes that must be met to enhance the water flux in FO processes, control the reverse salt flux, concentration polarization and foulin...

The utilization of seawater for drinking purposes is limited by the high specific energy consumption (SEC) (kW-h/m³) of present desalination technologies; both thermal and membrane-based. This is in turn exasperated by high water production costs, adding up to the water scarcity around the globe. Most technologies are already working near their the...

Membrane distillation (MD) is a thermally driven separation process with great potential, but is currently limited by low energy efficiency. Heating of the entire circulating feed represents a major source of energy consumption in MD. Here, we present electrically conductive carbon nanostructure (CNS-) coated polypropylene (PP) membranes as a possi...

The primary intention of this review is to showcase and quantify the level of research interest and current research trends, concerning UF membrane applications and processes within the past decade (2009–2018). Detected statistics manifested a resurgent interest in the UF technology on a yearly basis. "Journal of Membrane Science" and "Desalination...

Studies have previously been done on efficacies of chitosan and zeolite in ammonium ion (NH4+) removal. However, no study compares the adsorption performance of natural zeolite (NZ) and activated NZ (ANZ) with high molecular weight chitosan (HMWC) and low molecular weight chitosan (LMWC). Hence, this study investigates the potentials of NZ, ANZ, LM...

Membrane performance is a region of growing research interest, where new functional nanomaterials are continually sought. In this study, nano zeolite type Y was prepared through a unique ball milling process. The produced zeolite has a high surface area, and abundant flow channels with a well-defined pore structure facilitating water passage, but a...

Freshwater scarcity is one of the grand challenges that has posed threats to the global economy, societal stability and ecosystem balance. Desalination has been long recognized as an effective approach for fresh water production from seawater and brackish water. Forward osmosis (FO) is currently one of the most studied technologies for seawater and...

Salinity gradient processes, such as Forward Osmosis and Pressure Retarded Osmosis, have been proven to be promising technologies for reducing the energy consumption in water treatment processes, for energy production, and for energy recovery. Based on the thermodynamic concepts, specifically Gibbs' Free Energy of Mixing, the concentration of the d...

Scientific research today is marked by a growing differentiation and specialization in the disciplines and interdisciplinary research. This paper investigates a number of challenges of Interdisciplinary collaborations in implementation of a circular economy approach within textile and graphic designs. These challenges range from achieving economy o...

In this study, novel nano crystalline composite strings made from mixed nickel-tungsten oxides (NiWO4-WO3-WO2.9) have been fabricated. The NiWO4-WO3 fibers produced by the electrospinning method were post treated in an argon atmosphere at 800 °C which yielded NiWO4-WO3-WO2.9 nanocrystals attached together forming a string-like structure. The presen...

Study of forward osmosis (FO) has been increasing steadily over recent years with applications mainly focusing on desalination and wastewater treatment processes. The working mechanism of FO lies in the natural movement of water between two streams with different osmotic pressure, which makes it useful in concentrating or diluting solutions. FO has...

The research efforts on the development of ideal forward osmosis membranes with high water flux and low reverse salt flux have been devoted in the recent years. In this study, thin film composite polyamide forward osmosis membranes were prepared. The porous polysulfone (PSU), polyphenylsulfone (PPSU), and polyethersulfone (PESU) substrates used in...

Synthetic solutions assimilating irrigated groundwater containing varying concentrations of humic acid (10 mg/L), saline (10–35 g/L) and metal agents (5-10 mg/L), were processed through a ceramic microfiltration membrane (Sterilox Ltd., 0.5 μm). This was done with enrichment schemes using polymeric coagulants (PDADMAC) applied to enhance the remova...

Research on membrane technology to provide fresh water while considering inextricably linked energy issues has resulted in remarkable accomplishments in the production of membranes, such as thin film composite (TFC) membranes, for relatively low-energy desalination and wastewater reclamation via the forward osmosis (FO) process. Exhaustive and cont...

High demand for palm oil results in the production of huge quantities of palm oil mill effluent (POME) wastewater containing a high amount of organics. Currently, this is often processed by anaerobic digestion, but the waste water still requires further processing. Dewatering of POME digestate could simultaneously recover nutrients for use as organ...

Since its inception in the 19th century, microfiltration (MF) has evolved as a membrane-based separation technology for treating various effluents and wastewaters. This review aims to familiarize its readers with general and specific research trends on various topics in MF. The level of research interest has been measured by the number of publicati...

A novel parallel technique that couples the lattice–Boltzmann method and a finite volume scheme for the prediction of concentration polarisation and pore blocking in axisymmetric cross–flow membrane separation process is presented. The model uses the Lattice–Boltzmann method to solve the incompressible Navier–Stokes equations for hydrodynamics and...

Utilization of an integrated forward osmosis-solar powered membrane distillation system can provide a promising method for brackish water desalination. In this study, the brackish water feed and fertilizer draw solutions were operated in a forward osmosis process to generate irrigation water for agriculture. Forward osmosis was also selected as mem...

A conductive form of networked cellulose, prepared by incorporating carbon nanotubes, has been used in polyvinyl alcohol (PVA) membranes for reverse osmosis. The use of networked cellulose and carbon nanostructures (CNS) not only helps control the thermal, mechanical and electrical properties of the membrane, but also enhances RO performance and al...