Search

Pulsed electric field disinfection is an effective non-thermal water disinfection technology. Compared to conventional disinfection techniques, PEF inactivation has several advantages including no by-products. In this context, the use of silver ions in conjunction with a reverse osmosis filtration system has been proposed as a safe and cost-effective treatment approach that can be used in a point of use technologies. This system contains two silver meshes as electrodes inside a reverse osmosis membrane with the application of a pulsed electric field on it as a disinfection method, After conducting chemical and physical tests of the water samples before and after the treatment system, it was noticed that most of these characteristics were significantly affected by increasing the number of electrical impulses and the intensity of the applied voltage as a result of the increase in the ionization process of silver in water.

Enhancing the water permeation while maintaining high salt rejection of existing reverse osmosis (RO) membranes remains a considerable challenge. Herein, we proposed to introduce polymer of intrinsic microporosity, PIM-1, into the selective layer of reverse osmosis membranes to break the trade-off effect between permeability and selectivity. A water-soluble a-LPIM-1 of low-molecular-weight and hydroxyl terminals was synthesized. These designed characteristics endowed it with high solubility and reactivity. Then it was mixed with m-phenylenediamine and together served as aqueous monomer to react with organic monomer of trimesoyl chloride via interfacial polymerization. The characterization results exhibited that more “nodule” rather than “leaf” structure formed on RO membrane surface, which indicated that the introduction of the high free-volume of a-LPIM-1 with three dimensional twisted and folded structure into the selective layer effectively caused the frustrated packing between polymer chains. In virtue of this effect, even with reduced surface roughness and unchanged layer thickness, the water permeability of prepared reverse osmosis membranes increased 2.1 times to 62.8 L∙m–2∙h–1 with acceptable NaCl rejection of 97.6%. This attempt developed a new strategy to break the trade-off effect faced by traditional polyamide reverse osmosis membranes.

Recent years, membrane separation technology has attracted significant research attention because of the efficient and environmentally friendly operation. The selection of suitable materials to improve the membrane selectivity, permeability and other properties has become a topic of vital research relevance. Two-dimensional (2D) materials, a novel family of multifunctional materials, are widely used in membrane separation due to their unique structure and properties. In this respect, as a novel 2D material, graphitic carbon nitride (g-C3N4) have found specific attention in membrane separation. This study reviews the application of carbon nitride in gas separation membranes, pervaporation membranes, nanofiltration membranes, reverse osmosis membranes, ion exchange membranes and catalytic membranes, along with describing the separation mechanisms. © 2020 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd.. All rights reserved.

This current paper presented a new candidate and potentially to improve the current membrane materials in water filtration process. With that, the primary materials used in this research study is layered double hydroxides (LDH) nanoclay which can be obtained from earth minerals and self-synthesized from inorganic salts were discussed thoroughly to help a better understanding of these materials. However, the current technologies of water separation were still lagging behind and ineffective especially in removal of divalent metal ions and multivalent salts. Infeasibility of reverse osmosis membrane make it not a viable option for divalent salts filtration. With that, nanofiltration (NF) membrane offered as an alternative to substitute available method. In this study, thin film nanocomposite (TFN) membranes were fabricated by incorporating layered double hydroxides (LDH) nanoclay. The LDH nanoclay with different loading ratio of 0, 0.05, 0.1, 0.15 and 0.2 were impregnated into polyamide layer on top of polysulfone substrates. The fabricated TFN were characterized in terms of physicochemical properties (SEM and FTIR) and membrane hydrophilicity (contact angle). After the addition of LDH, the morphological structures of TFN membranes were changed and the surface hydrophilicity was enhanced significantly. FESEM images displayed a typical ridge and valley morphology with nodule-like structures. As the LDH loading was increased, the contact angle decreased from 34.56˚ to 15.76˚ showing the surface hydrophilicity of membrane is improved. The separation performance of membrane was evaluated in terms of salt rejection ability by cross flow filtration system. The best performance NF membrane was found to be TFN 0.05 with high water flux and MgCl2 rejection with values of 24.18 L/m2.h and 91% respectively. This study has experimentally validated the potential of LDH materials in membrane process for improvement in water separation process.

In the last few decades, Water Pollution by heavy metal waste has become a sober problem of concern. There are several conventional methods available for removing heavy metals such as chemical precipitation, flotation, ion-exchange, membrane filtration, reverse osmosis, electro dialysis, ultrafiltration, nanofiltration, coagulation, flocculation etc. Among the available methods adsorption is considered to be a suitable alternate due to its simplicity, effectiveness, cost-effective, versatility and safeness. Adsorption is an ideal method and adsorbent is one of the important factors which determine the efficiency of adsorption. This review throws an eloquent report on the removal of various heavy metals and its toxicity, using Perovskite as adsorbent and discusses the various factors which influence the adsorption process such as pH, initial concentration, temperature, adsorbent dosage, and contact time. In addition to it, associated Δ G ∙ (standard Gibbs free energy change), ΔH° (standard enthalpy change), ΔS° (standard entropy change), adsorption kinetics involved by pseudo-first-order, second order model and equilibrium adsorption by Langmuir and Freundlich isotherms are also debated. The efficiency of regeneration and reuse of the adsorbent by various methods are also summarized. This review will help the scientific community working on adsorption to choose a suitable adsorbent Perovskite for the heavy metal removal.

High operation and maintenance costs, and ‘last-mile’ issues for populations not connected to municipal water infrastructure, have limited the utility of centralized reverse osmosis (RO) systems to alleviate water availability issues for rural communities. To address these challenges, a decentralized RO module which employs tubular RO membranes was designed and investigated. The system represents an appropriate technology because it requires minimal pretreatment and it fits in self-contained, low-profile suitcase. This compact desgin also incorporated innovative 3D printed static mixers to minimize salt concentration polarization and to improve performance. Since grid electricity may also be discontinuous in the target use cases, the system was tested with two direct current (DC) power solutions: a photovoltaics-battery configuration and an alternator-battery. The final prototype weighs less than 15 kg and was found to have a production capacity of ∼8 L/h, consuming ∼100 W of pumping power. Experiments of the prototype module revealed a 96% rejection rate of salt from a 1000–2000 ppm synthetic groundwater solution and a >99% rejection coefficient for bovine serum albumin protein and humic acid. From these performance metrics, it was estimated that 36 sets of this decentralized system (with a total CapEx of US$23,400) could provide drinking water for ∼600 rural households at a unit cost of water of 1 LKR/L (0.005 USD/L) in Sri Lanka. Overall, this study demonstrates how computational modeling and 3D printing can be leveraged to develop a compact and cost-effective decentralized RO package that could be rapidly deployed to water-stressed rural areas and in disaster relief applications.

Graphene is novel & invigorating nanocarbon material that has drawn in both scholastic and industrial interest in last 10–15 years. It is by and large widely investigated as a result of its extraordinary properties including, superior mechanical and non-corrosive property, amazingly high surface area, great optical translucency, outstanding electrical and heat carrying properties and so forth. More importantly, these properties can be tailored to some extent by developing different grades of derivatives of Graphene. In this report, a various routes used to produce Graphene & Graphene-based materials are reviewed, detailed review of recent progress in application of these materials for desalination of water and purification of air is presented. Various attributes of Graphene & its derivatives which can revolutionise the air filtration & water desalination processes are underlined. Graphene Aerogels and doped sheets prove to be efficient alternates for air filtration & pollutant removal applications with relatively high specific surface area of around 1300 m2/g [24]. These doped derivatives show improved adsorption efficiency around 55–65% [25], which is studied to be rising with energy inputs like potential difference. Graphene and its derivatives-based water filtration is proving to be extremely efficient than the conventional water filtration & desalination mechanisms. Reverse Osmosis (RO), one of the widely used conventional methods of desalination comes with a large expense of money and energy but yields low volumes of filtered water. About 85–95% of input water gets wasted in the RO mechanism, yielding only 5–15% of usable water. The conventional Solar desalination is more efficient as compared to RO, but even that can be improved by 70–90% [45-47] by incorporating Graphene and its derivatives as part of a volumetric system, light absorbing layer and filtration layer in Solar Desalination process. The graphene-based membranes because of their high permeability and excellent ion repellency can be used for desalination applications with a removal efficiency of 33–100% [61] depending on the pore size and the applied pressure. Capacitive Deionization method of desalination can also be a very efficient alternative to the RO due to its minimal energy requirement of only 0.1–2.03 kWh/m3 [52].

Acid mine drainage (AMD) is a multi-factor pollution formed from complex chemical, physical, and biological interactions that takes place under ambient conditions in abandoned and active mines. Over the years, researchers have been investigating ways to mitigate its potential impact on the environment through various treatment technologies. The aim of this review was to critically analyze the broad spectrum of treatment methods that have been engaged in published literature on the remediation of AMDs. Adsorption treatment using zeolites, fly ash, biochar activated carbon, clay-based minerals and biomass-based adsorbents was discussed. Given an appropriate choice of adsorbent, ions in AMD can be reduced between 50% and 99%. Membrane separation processes like nanofiltration, reverse osmosis and hybrid systems were discovered to be more effective than adsorption and can effect over 90% rejection at optimized conditions. Biological processes showed a far wider range of performance amongst all treatment types due to the selectivity in performance of the different micro-organisms used although Advanced Oxidation Process (AOPs) have been shown to achieve>80% ions removal. In all biological processes studied ranging from wetlands to bioreactors, algal bioreactors seemed the most effective in this domain. Most of these treatment technologies are corrective while preventive techniques can be explored to prevent the production of AMD. Despite the positive outcomes of the different types of treatment, they have associated technical issues. It is recommended that more preventive techniques be explored to reduce the production of AMD. The review discussed how AMD treatment would affect environmental protection and water resource management.

Water supply in rural islands or coastal areas is a basic task for people's livelihood. The all-pervading reverse osmosis (RO) technology is an energy-intensive process. To achieve sustainability goals, the development of renewable driven power supply system for RO plant is significant. Nowadays, the energy, economic and environmental indicators have rarely simultaneously investigated for the type of renewable power supply system with underwater compressed air energy storage (UW-CAES) for RO plant. In this paper, an energy-economic-environmental trade-off multi-objective optimization for such system is proposed in both grid-connected and off-grid schemes. A bi-level optimization strategy based on MOPSO algorithm and TOPSIS method is adopted to seek the optimal configuration and energy management strategy. A real-world case is implemented to demonstrate this method. The results show that the TPC/COE/EC set in optimal grid-connected scheme system is 3.716 × 106¥/0.814¥kWh−1/795.922 kg with a configuration of 511 PVs, 12 WTs and a 900 m3 bag volume in UW-CAES. Whereas, the TPC/COE/EC in optimal off-grid system is 4.076 × 106¥/2.305 kWh−1/566.254 kg with a 705/8/900 m3 configuration. In energy perspective, both schemes can match the load well. In economic perspective, the grid-connected scheme has a considerable profit, whereas the off-grid has no revenue. In environmental perspective, both schemes can reduce the carbon emission remarkably.

Exposure to bioaerosols in enclosed livestock facilities have been reported to pose health risks to workers and animals. Environment-friendly methods for reducing bioaerosol levels in enclosed animal production units could provide important environmental control options. In this study, laboratory-scale electrospray modules were developed to generate engineered water nanostructures (EWNS) to inactivate microbes. The EWNS were generated using three spray liquids (reverse osmosis (RO) water, saline water, and NaOH solution). The physicochemical properties (size, lifetime, reactive oxygen species (ROS) content) of the generated EWNS were characterised. Results showed that the average diameter of the EWNS droplets ranged from 40 to 45 nm. It was found that approximately 17% of the generated EWNS was still present after 4.5 h, and that the most predominant ROS generated was OH·. Furthermore, the efficacy of the generated EWNS in inactivating Escherichia coli was assessed under conditions relevant to livestock facilities. The electrospray modules were installed in an acrylic chamber, which was used to simulate the airspace in an animal barn. After 60-min treatment, reductions in E. coli concentrations inside the chamber were 69%, 64%, and 50% using RO water, saline water, and NaOH solution, respectively, at a ventilation rate of seven air changes per hour (ACH). At 15 ACH, the efficacy of the EWNS generated using RO water was 37%. The results show the potential of the EWNS technology as a microbial decontamination method for animal confinement buildings; however, in-barn tests are necessary before it can be fully implemented in commercial livestock barns.

Recently, the rapid worldwide growth of seawater reverse osmosis (SWRO) desalination capacity has reignited the boron removal challenge in drinking water. The objective of this review is to discuss the recent advances and patents in boron mitigation strategies in SWRO systems, and to present the energy and environmental concerns of SWRO desalination system with boron rejection. First, the operating parameters of SWRO systems that affect boron removal are presented, before we discuss the reported findings and patents of boron control improvement from the standpoint of membrane materials advancement and from the development of various configurations, such as double pass reverse osmosis and hybrid SWRO processes with other separation technologies like ion exchange (IX), nanofiltration (NF), and electrodeionization (EDI). Thereafter, issues over SWRO desalination’s detrimental environmental impact are reviewed: thus, seawater intake, brine discharge, and energy consumption constitute the main weaknesses. Then, sustainable solutions are proposed to reduce the environmental burdens. As SWRO desalination is an energy intensive process, exergy analysis emerges as a key tool to assess the performance of this process. Therefore, the use of exergy analysis to SWRO desalination in general and, as an example, to a full-scale SWRO desalination plant located in Spain, are discussed. The findings indicate that the SWRO unit is responsible for over 64% of exergy destruction due to the irreversibilities associated with the large pressure drop and the high salinity of the brine.

Outer-selective thin film composite (TFC) hollow fiber membranes have the advantages of fiber blockage with less pressure drop and high surface area module. This work highlights novel strategies to design continuous interfacial polymerization that can allow mass production, performance controllability, and small margin of error in performance. Processing parameters were symmetrically optimized to maximize high water flux and salt rejection using poly(piperazine-amide) TFC membranes. For further improving the membrane performance, polyvinyl alcohol was incorporated for an interlayer, thereby having the water flux of 48 LMH/bar and the salt rejection (Na2SO4) of 99.6%. The system can be used in a variety of applications such as reverse osmosis, forward osmosis, or gas separations by simply replacing the monomers.

Carbon nanotubes (CNTs) are promising for realizing ultrafast membranes with implications to molecular separations and beyond. However, it is a big challenge to harness the potential of CNTs for designing scalable yet high-performance membranes. Here we systematically explore the role of loading and vacuum-assisted alignment of CNTs for improving the desalination performance of polyamide (PA) based thin-film composites. To rule out the dispersion instability issues, we focused on carboxylated single-walled CNTs (SWCNTs) commercially available in the market. After applying a pre-treatment for cleaning, we deposited SWCNTs on porous polysulfone supports by vacuum filtration and coated a PA layer on top via interfacial polymerization. Morphological assessments supported by polarized Raman microspectroscopy allowed the quantification of SWCNT alignment. At an optimum SWCNT loading, which we found critical for alignment, the water permeability of resulting membranes significantly improved without compromising NaCl selectivity. Also, we achieved an improved boric acid selectivity, arguably owing to the hydrophobic nature of nanotube channels. Moreover, nanotubes promoted resistance against chlorine degradation and improved mechanical strength. Vacuum deposition is instrumental for infiltrating SWCNTs into the support layer, but a mat layer forms between the support and PA layers when SWCNT loading exceeds the limit that the support pores can accommodate. Given that we use ordinary SWCNTs and a scalable methodology (vacuum-assisted infiltration), the developed membranes are promising for practical applications. © 2021 Elsevier Ltd

The utilization of renewable energy to run desalination plants has enormously expanded in the last two decades. In this study, a grid-connected hybrid solar-wind system is proposed to power a small-scale Reverse Osmosis (RO) desalination unit. In a case study, the system's performance has been analyzed under the weather conditions of the Eastern Province, Saudi Arabia. A numerical model has been developed based on a mixed-integer linear programming (MILP) approach to design and size the proposed system. The developed model is solved on an hourly basis to capture hourly variations of weather conditions with the aim to obtain an efficient design to operate the RO plant and supply freshwater to a small community living in a remote area at minimum cost. The developed model allows finding the optimal number of wind turbines, the number of photovoltaic (PV) modules, and the energy purchased from the national grid. Since the desalination energy consumption depends on the feed water conditions, two energy consumption rates are considered, namely, 2 and 4 kWh/m3. The results show that brackish water can be purified for the two different energy requirements at a cost varying between 1.72 and 1.84 $/m3, respectively.

Solar desalination is a promising technology to reduce the costs and environmental impact associated with the use of fossil fuel resources. Currently, almost all reverse osmosis (RO) desalination technologies powered by solar thermal energy are based on organic Rankine cycle (ORC) systems. Considering the significant advantages of the Stirling cycle in the utilization of solar energy, in this paper we present a RO desalination system powered by a solar dish-Stirling (DS) engine; a detailed parametric analysis based on finite-time thermodynamics is carried out to evaluate the water productivity as well as the energy and exergy efficiency of the system. The water productivity monotonically increases with increasing absorber temperature, while the optimal absorber temperature for maximum energy and exergy efficiency ranges from 1100 to 1300 K. Linear correlations are found between the optimal working fluid temperature of the source side and the maximized water productivity, energy/exergy efficiency, and average absorber temperature. The water productivity and energy/exergy efficiencies show an initial increase followed by a decrease with increasing sink side temperature. Among these properties, the stagnation point for maximum water productivity is found at a higher sink side temperature.

The combined heating, cooling, power (CCHP) and freshwater system are designed separately with two types of desalination plants including multi-effect desalination with thermal vapor compression (MED-TVC) and reverse osmosis (RO). This combined system meets the heating, cooling, power and fresh water needs of a hotel in Iran. Gas turbines and diesel engines are considered as prime movers (PM) for conversion of fuel to power and heat. The integration of the CCHP system with RO desalination was investigated in two modes of RO without colloidal fouling (first day of operation) and with colloidal fouling formation rate in a period of 90 days. The genetic algorithm (GA) was implemented to find the optimal values of 21 design parameters in the case of CCHP system with RO desalination and 22 design parameters in the case of CCHP system with MED-TVC desalination to minimize the annual cost. Optimization results showed that the diesel engine prime mover has a greater advantage over the gas turbine in the all studied modes. In addition, combination of CCHP + RO without colloidal fouling and with colloidal fouling and combination of CCHP + MED-TVC with diesel engine as PM showed 9.66 %, 1.80 % and 11.68 % reduction in annual cost compared with gas turbine as PM, respectively.

In this paper, the feasibility of hybrid nanofiltration-reverse osmosis (NF-RO) process to remove hardness in brackish water at higher recovery rate and concentrate minimization is investigated. Two nanofiltration (NF) membranes are tested in the first stage for selecting the appropriate membrane on the basis of lower applied pressure and higher permeate flow. Then the evaluation of the performances of hybrid NF-RO system of each stage is studied in terms of recovery rate and Langelier saturation index (LSI) values to prevent the corrosion potential. The blending strategy is adopted with NF brine and reverse osmosis (RO) permeate in order to bring the RO permeate characteristics in accordance with drinking water standards and to minimize the volume of NF brine. Also, energy consumption performance of conventional nanofiltration (NF-NF) and NF-RO hybrid system in hardness removal is compared. The results show that the NF-RO hybrid system combined to blending strategy provides the simplest process but most energy efficient process compared to a single conventional NF-NF. Moreover, including NF upstream of RO is responsible of the increasing of the overall water recovery rate (95 %) and of the permeate quality with lower total dissolved solids (TDS). However, less water with lower salinity treated by RO increases significantly the recovery rate in RO stage up to 80 %. The portion rate of NF brine blending with RO permeate is equal to 32.45 %, corresponding to 240 L/h, which meet the water quality regulations for drinking water. Hybrid NF-RO system has a lower energy cost per m3 than NF-NF, it is around of 0.055 $/m3. At the same time, this procedure minimizes the fraction of brine disposal dumping to sewage, making it environmentally friendly.

A series of polymeric membranes were synthesized by blending polyurethane with sodium alginate (0.2, 0.4, 0.6, 0.8 and 1.0%). The structural, morphological and thermal properties of the membranes were examined by FTIR, SEM, AFM and TGA, respectively. Performance evaluation (salt rejection and flux) was assessed through reverse osmosis technique (RO). The FTIR spectra of membranes confirmed extensive hydrogen bonding (3350 cm−1). The SEM and AFM analyses supported a progressively rising surface roughness of blended membranes. The hydrophilicity, crosslinking density and thermal stability of the membranes were improved with an increase in alginate content. The capability of salt (NaCl and MgCl2) rejection was improved with alginate up to 0.8%. In addition, the rejection of divalent ions was better than monovalent ions (94 ± 0.96% for NaCl and 98 ± 0.98% for MgCl2). The blended membranes ascertained an effective chlorine resistivity. The antibacterial activity was also promising, which enhanced with the alginate content in the membrane. The sodium alginate blended membrane with polyurethane proved to be an efficient approach to develop the blended membranes with tunable properties for water desalination.

Reverse osmosis concentrated leachate (ROCL) from landfill leachate treatment contains high amounts of refractory organics. In this study, a combination of polymerized ferric sulfate (PFS) and nanoscale zero-valent iron/peroxymonosulfate/ozone (nZVI/PMS/O3) approach was adopted to remove refractory pollutants in ROCL. The effects of coagulant species, dosage and initial pH on the pre-treatment of organics from ROCL during coagulation process were investigated. Moreover, the influences of experimental factors, including initial pH, ozone doses, PMS, and nZVI on the removal of refractory organics in ROCL from coagulation effluent were systematically studied. The characteristics of organics were determined by using microscopic, spectroscopic and electron paramagnetic resonance (EPR) analyses. The batch experimental results indicated that the refractory organic contaminants in ROCL were effectively removed through PFS-nZVI/PMS/O3 treatment. The maximum removal efficiencies of COD and TOC were 89.1% and 83.2% under the optimum conditions: PFS of 8 g/L, ozone dose of 100 mg/min, PMS dose of 1.5 mM and nZVI dose of 10 mM, and at these conditions, the biodegradability index (BOD5/COD) was enhanced from 0.02 to 0.32. The excitation-emission matrix fluorescence spectroscopy (EEM) analysis indicated that humic-like and fulvic-like substances in ROCL were effectively removed. According to EPR analysis, hydroxyl and sulfate radicals were the dominant reactive species for the degradation of organics in nZVI/PMS/O3 system. Overall, the environmental and economic analysis suggested that the PFS-nZVI/PMS/O3 system was a cost-effective method for cleaning refractory organics from ROCL.

Membrane Distillation (MD) is an emerging technology that, on a technical level, has been demonstrated to be a promising technique in regard to enabling the provision of potable water in remote areas and arid regions. Though extensive studies have invested their efforts in optimizing the operating parameters of MD, few have focused on investigating its economic feasibility; a real-world constraint that limits even the most effective of inventions. This study provides a systematic evaluation of the economics involved in using an MD system to produce potable water from brackish water. This study takes into consideration both the direct and indirect effects of identified key parameters (plant size, use of waste heat, membrane permeability). Results indicate that individually, utilizing solar energy, waste heat recovery, and reducing the plant size significantly impact the final cost of water purified, ergo water price (WP). Likewise, combining solar-thermal sources with waste heat to power MD processes can in turn result in a greatly lowered water price. For instance, a MD system relying on waste heat and solar thermal (providing 40% and 60% of its energy requirements respectively), can lower water price from $6.80/m3 (the price of operating a standalone MD solely powered by grid electricity) to a mere $1.6/m3. Finally, a sensitivity analysis was performed to optimize the cost savings that can be realized via the MD process. It was shown that increasing membrane permeability and contribution of renewable energy (i.e. solar-thermal and waste heat) used in operating the process, while reducing the desalination plant capacity, would likely result in a significant decrease in the water production cost of MD, leading to a more competitive, sustainable, and economically-feasible desalination process for small-scale and remote applications.

Reverse osmosis (RO) has been shown to be an efficient treatment method for radioactive wastewater, which has been employed in nuclear power plants. However, the fouling on RO membrane surface should be solved to fabricate modified RO membranes with selective and fouling-resistant surface, which is essential for the further widespread application of RO. To provide fundamental insights into fouling control methods, the influence of surface properties on surfactant fouling was investigated with modified RO membranes. The results showed that surfactant fouling reduced the flux of RO membranes by 35 %–75 %. The interfacial free energies associated with the surfactants and RO membranes surface were calculated by XDLVO theory to explain surfactant fouling mechanisms. The interfacial free energies associated with CTAB and RO membrane surface increased from 3.18 to 41.22 and 69.62 mJ m−2 and SDBS increased from 20.21 to 34.07 and 43.97 mJ m−2, Tween 80 increased from -2.63 to 3.98 and 9.61 mJ m−2 with PEI and EPTAC grafting. The results indicated that the changes of interfacial free energies were mainly caused by the changes of membrane hydrophilicity and surface charge. Fabricating RO membrane with hydrophilic and neutrally charged surface was potential for improving all kinds of surfactants resistant capability. Besides, surfactant fouling had great influence on membrane permeability. The changes of radioactive nuclide rejections were mainly caused by the changes of membrane surface charge while the increase of boron rejection was attributed to the rise of membrane surface steric-hindrance. Therefore, the membrane hydrophilicity and surface charge should be carefully considered in radioactive wastewater containing surfactants treatment.

Reverse osmosis (RO) is one of the most successful membrane technologies for desalination and contaminant removal from water. RO is applied globally, and can be used for both small- and large-scale applications. To characterize membrane performance, standard testing uses membrane coupons and a NaCl solution in a labscale setup under controlled conditions. Ideally, experiments are done for a range of applied hydrostatic pressures and salt concentrations, with water flux and salt rejection measured in each experiment. This full dataset can then be checked for internal consistency, and all these data must then be described by a comprehensive theoretical framework, i.e., we need an appropriate set of equations to parametrize these data. Parameters derived from this procedure, such as water and salt permeability, can then be compared to those obtained in other studies, for other membranes, salts, or temperatures. If this theory indeed correctly describes data for water flux and salt flux, it can also be applied in larger scale models for RO modules and combinations of modules, which are the basis of engineering design and economic optimization. Herein, we present a novel equation for salt flux that we derive from the full solution-friction (SF) theory. This equation interpolates between an equation for neutral membranes on the one hand, and an equation for highly-charged membranes on the other hand, and thus it is more generally applicable. We apply this new equation to several datasets of seawater RO membranes, and we propose an accurate method to compare the salt permeability of different membranes.

Biofouling is a ubiquitous problem in many industrial systems including reverse osmosis (RO) desalination units where the biofilm impedes the water flow. It is essential to develop novel cleaning methods that are non-damaging and environmentally friendly. The most promising cleaning agents are enzymes, which can selectively cleave the components that stabilize the biofilm. However, biofilm-degrading enzymes are often difficult to identify due to the unknown matrix composition and lack of effective screening methods. To overcome this, a flexible screening platform was developed to evaluate enzyme treatment on fouling removal directly on RO membranes. The developed platform was used to identify enzymes that could degrade biofilms on fouled RO membranes. The membrane biofilms were destabilized by a range of enzyme groups, most effectively by proteases, lipases, DNase, cellulolytic enzymes, and pectin-degrading enzymes. The most effective enzyme formulations could clean the membranes more effectively than conventional chemical cleaning agents, removing 45 % of the biofilm compared with 0 %–19 % for the chemicals (p ≤ 0.001), indicating that enzymes have the potential to replace or complement chemical cleaning. The screening platform thus proved a potent tool for systematically studying biofilms and could be applied to combat biofilms in many other applications.

Membranes are widely used in separation processes due to their low energy requirement, small footprint and simplicity. New membranes have been developed based on novel materials and fabrication techniques to address separation challenges in the field of membrane science. In the case of liquid phase separations, ion-ion separation and chiral resolution using membranes have attracted growing interest for their applications such as in high-value mineral extraction and pharmaceutical manufacturing. Furthermore, reverse osmosis operation favors ultra-high-pressure range for treating feed with higher salinity with higher water recovery. Herein we highlight the latest development and design approaches of single species-selective membranes and pressure-resistant membranes and discuss the current limitations of membrane separation in the liquid phase. We subsequently review recent advancement in the fabrication techniques that enable the making of these membranes from emerging materials.

The ability to reuse boron and minimize the volume of radioactive waste could be accomplished with modified reverse osmosis (RO) membranes. RO membranes were fabricated via polyethylenimine (PEI) grafting to separate silicon and radionuclides from boron-containing radioactive wastewater. The positively charged RO membrane promoted more efficient removal of nuclides and silicon while the rejection of boron declined from 55.88 % to 41.71 % after modification. Compared with virgin RO membrane, the SFB-Si, SFB-Cs, and SFB-Co of the modified RO membranes increased from 6.02, 5.16, and 12.62–29.52, 61.91, and 547.15, respectively. SFB-Si, SFB-Cs, and SFB-Co of the simulated RO system with modified RO membranes further increased to 156.96, 1068.12, and 83617.88, respectively. As a result, permeate water with 433.92 mg L−1 boron, 0.04 mg L−1 silicon, 1.62 μg·L−1 Cs(I), and 0.02 μg·L−1 Co(II) was obtained, which could satisfy radionuclide treatment requirements and allow for the reuse of boron. Overall, modified RO membranes would be able to reuse boron and minimize the volume of discharge of radioactive wastewater.

The management and treatment of brine (saline wastewater) are of great importance, as its discharge to the environment poses a significant threat. A new strategy called minimal liquid discharge (MLD) appears to be a promising and more cost-effective option than zero liquid discharge (ZLD) as it uses only membrane-based technologies, leading to up to 95 % freshwater recovery. This research study introduces and presents for the first time a techno-economic assessment of five MLD treatment schemes that can be implemented in the brine treatment. The technologies included are reverse osmosis (RO), high-pressure RO, forward osmosis (FO), osmotically assisted RO (OARO), and membrane distillation (MD). Results showed that the MLD schemes costs ranged from US$0.79/m3 to US$1.36/m3, while the freshwater recovery ranged from 78 % to 89 %. In schemes 2 and 5, the implementation of MD substantially increased the energy consumption (>20 kW h/m3), however, these schemes were more economical (

Biofouling is recognized as one of the most problematic fouling types in reverse osmosis (RO) processes and lead to high energy requirements and operating costs. Over the past decade, many studies on membrane bioreactor (MBR) systems for wastewater applications demonstrated that disrupting cell-cell communications among bacteria, called quorum quenching (QQ), is a promising approach to inhibit biofouling of membranes. Here, we developed the QQ-column as a novel strategy to control biofouling in RO systems. The QQ-column was prepared by incorporating a recombinant bacterial QQ strain into hydrogel beads and embedding these beads inside a column. The QQ-column was installed upstream of the RO module to degrade N-acyl homoserine lactone, a quorum sensing (QS) signal, from the feed in a laboratory-scale RO system operating in total recycle mode. The QQ-column reduced the concentrations of signal molecules by ~29% in an RO system and mitigated biofilm formation (38.6% reduction of cell number) on the membrane, consequently reducing the transmembrane pressure by 50.1%. These results demonstrate that integrating QQ bacteria into columns is a practical method to control biofouling in RO systems. Economic Development Board (EDB) National Research Foundation (NRF) Accepted version This study was supported by the Research Fund for a new professor by the SeoulTech (Seoul National University of Science and Technology). We also acknowledge financial support from the Singapore Centre for Environmental Life Sciences Engineering, whose research is supported by the National Research Foundation Singapore, Ministry of Education, Nanyang Technological University and National University of Singapore, under its Research Centre of Excellence Programme. The funding support from the Economic Development Board (EDB) of Singapore to the Singapore Membrane Technology Centre (SMTC), Nanyang Environment & Water Research Institute (NEWRI), Nanyang Technological Univer- sity (NTU) is also acknowledged

This work aims to investigate the polyamide (PA) morphology on polysulfone (PSf) membrane supports with different morphologies. It was achieved by systematically varying the N-Methyl-2-Pyrrolidone (NMP) and Dimethylformamide (DMF) solvent composition ratios in dope solution as adapted in Tiraferri et al. The PSf membrane support was firstly synthesized via phase separation technique. Next, the PA layer of the thin film composite (TFC) membrane was synthesized via consistent interfacial polymerization parameters on the PSf membrane support. The PA layer over the resulting array of membrane supports was investigated on their surface wettability, top and cross-sectional morphologies, and performances. Result shows that with more NMP content in the dope solution produces thin and dense sponge-like top skin layer with intense extended finger-like macrovoids sublayer. Meanwhile, more DMF content in the dope solution produces thicker and dense sponge-like morphology on the top skin with finger-like pores underneath. A layer of smaller and loosen ridge-and-valley PA structures is formed on the thicker and dense sponge-like morphology. TFC membrane over support made of NMP to DMF (40:60) was observed had the highest hydrophilicity with the lowest contact angle measurement of 61.9 ± 3.1°. It also performed the highest water permeability of 4.06 LMH/bar, moderate salt rejection of 95.65% with salt permeability of 1.9 gMH.

This research paper is accomplished for designing reverse osmosis membrane for desalination and softening of groundwater at Tikrit University Site. The raw groundwater has TDS ranged between 1570 and 2910 mg/L, temperature, (23–25)C pH(6.27–8.6), Electrical conductivity (3070–3620) µs/cm, Ca(492–640) mg/L, Mg(41–437) mg/L, Total hardness (1400–3400) mg/L, SO4 (700–1296) mg/L, NO3(18.5–40) mg/L. Dissolved oxygen (1.5–4.5) mg/L and Turbidity (1.3–5)NTU. ROSA72, Reverse Osmosis System Analysis is applied to design the reverse osmosis system for softening the groundwater. The result showed reliable design criteria and high quality water which are feed water 0.3 m3/h, feed press 7.91 bar, concentration flow 0.26 m3/h ,membrane area 2.6 m2 permeate flow 0.05 m3/h. water recovery 15%, permeate TDS 39.41 mg/L. ROSA-72 software can be used efficiently in design of reverse osmosis systems.

The fresh water scarcity is the contemporary issue for all areas around the globe due to available water getting polluted by various anthropogenic activities. The conventional Reverse osmosis (RO) system for purification of water needs electricity for its working and generation of electricity by conventional source emits polluting elements which is detrimental for the environment. Unlike conventional RO system, solar based water purification system called solar still is environment friendly and has the potential to mitigate the contemporary issue of fresh water scarcity. Various designs and material selection has been reported by researchers around the globe. In this review work, an effort by authors have been put to summarize double slope solar based water purification units by incorporating different kinds of collectors. After studying different solar based double slope water purification units, a comparison has been made on the basis of yield. It has been concluded that solar based double slope water purification unit incorporated with evacuated tubular collectors is better than other similar setups.

In this work, the FO and PRO experiments were performed using GE Osmonics reverse osmosis (RO) and cellulose triacetate (CTA) FO commercial membranes. Both RO and FO commercial membrane become the benchmark for the PRO membranes modification. The effect of draw solution concentration on water flux, salt reverse flux and membrane type on FO and PRO performance pressure were systematically investigated. The results showed that permeate flow increased with greater draw solution concentration in both FO and PRO modes. In the PRO process, the commercial GE Osmonics RO and CTA FO membranes could only be operated at a pressure not>7 bar with peak power densities achieved of 1.98 Wm−2 and 3.17 Wm−2, respectively.

The presence of protein, carbohydrate, and lipids in dairy wastewater reduces its biological treatment efficiency. However, separating these compounds before wastewater treatment will have economic benefits for the dairy industry, (i) protein and carbohydrate could be used as an alternative nutrition source of farm animals, and (ii) the efficiency of the existing wastewater treatment facilities will be improved. Membrane technology (ultrafiltration UF, nanofiltration NF, and reverse osmosis RO) in combination (UF-NF or UF-RO) has been used for the treatment of dairy wastewater. However, these technologies are pressure driven and energy intensive, further the presence of protein and carbohydrate results into fouling in NF and RO. The present study reports the application of UF and forward osmosis (FO) membrane processes. FO is a concentration driven membrane process which involves migration of water through a semi permeable membrane from low osmotic pressure (feed solution) to high osmotic pressure (draw solution). It results into less fouling than NF or RO. The present study involves an integrated treatment process with UF followed by FO, it has resulted into 65% of carbohydrate retention and 98% of protein retention.

Water security is a pressing issue for global citizens in the 21st century. Concerns over clean water supply, and the environmental impact of industrial waste water, make water treatment a world-wide problem requiring a simple and effective solution. Membrane distillation is an emerging water purification technique that complements state-of-the-art reverse osmosis processes. Membrane distillation achieves high rejection over a range of salt concentrations while maintaining flux, using a temperature differential as opposed to pressure across the membrane. Importantly the process can be driven using low grade waste heat energy. Current membranes used in membrane distillation do not guarantee stable membrane performance under harsh (high salt and acid or base concentrations) conditions. Here we report, a permeable graphene membrane operating in harsh conditions with no observable degradation. A permeate of pH neutral water with a flux of 25 ± 1 L m−2 h−1 is produced by this membrane through near (99.9 ± 0.1%) ion rejection from 0.6 M sodium chloride at pH 1 and pH 13, over 144 h. More complex ion solutions, including real acid mine drainage waste-water, were also successfully purified. These findings may present a membrane that is suitable to improve water supply and reduce the environmental impact of industrial waste-water.

The undesirable health impacts on humans have been observed across the world due to the consumption of arsenic polluted groundwater, particularly in Southeast Asia. In India, West Bengal is the most affected state from groundwater arsenic contamination. Increased arsenic exposure can cause diseases like arsenicosis, skin lesions, cancer, and other health hazards. In this context, arsenic removal is very essential. There are several separation techniques available for arsenic removal like chemical precipitation, ion exchange, adsorption, and reverse osmosis but they have some major disadvantages. Therefore, in the present study, to overcome the demerits and enhance the removal efficiency instead of single process combined ultrasonication and electrocoagulation has been carried out for the arsenic removal from simulated groundwater. The influence of initial concentration variation was examined at various range of initial arsenic concentration (0.1 mg/L, 0.3 mg/L, 0.4 mg/L, and 1 mg/L) under the constant operating conditions of pH (7–8), applied voltage (3–4 V), current density (20.83 A/m2), inter-electrode distance (0.02 m), submerge depth (0.04 m), effective electrode area (0.0024 m2), and ultrasonic frequency (40000 Hz). The experiments lead to the 90% of the removal in duration of 60 min of electrocoagulation. Additionally, the higher current density during electrocoagulation process has also played a vital role by offering 98.108% of arsenic removal. Consequently, for the removal of hazardous pollutant like arsenic, combined ultrasonication and electrocoagulation process is proficient and effective treatment option.

Water is essential for all human beings, animals, plants and other living organisms. The common methods of desalination salt water for production of fresh water by distillation, reverse osmosis and electro dialysis are intensive energy techniques. However, in remote arid areas, the desalination needs not exceed a few cubic meters per day. This decentralized demand favour local water production by developing other desalination processes, especially those using renewable energy. Present work to compare the effect of water depth, single slope and double slope and charcoal as energy storage material is filled in the cylinder and is placed in the still basin in vertical and horizontal positions also compared with the conventional still. To maintain at minimum depth of water in the basin is 0.01 m.

Thin film composite (TFC) reverse osmosis (RO) membrane has been dominating commercial desalination process for several decades since its inception in the 1970s. Despite the ability of generating high quality water at promising water permeability, the commercial TFC RO membrane is still susceptible to fouling and chlorine attack which lead to performance instability as a function of operation time. Over the past decade, the prowess of nanomaterials integration in overcoming the drawbacks of conventional TFC membrane has been proven by many research studies and this has led to the significant progress of thin film nanocomposite (TFN) membrane development. However, it remains a great challenge in integrating the inorganic nanomaterials with the polyamide (PA) selective layer of TFN membrane due to the incompatibility between organic and inorganic materials and the uneven distribution of nanomaterials. In view of this, this article intends to critically review various fabrication techniques that have been developed or modified to incorporate nanofillers within or atop PA layer for the development of TFN membranes. In addition, the essential characteristics of nanofillers in order to achieve good integration with PA layer as well as their impacts in improving membrane performance with respect to water flux, rejection, antifouling, antibacterial and chlorine stability are also reviewed. We hope this review article could provide insights to researchers in fabricating defect-free TFN RO membranes for enhanced water desalination.

Membrane technology plays a vital role in various applications like desalination, ultrafiltration, nano-filtration, reverse osmosis and wastewater treatment. Janus membranes (JMs) are a unique class of polymers having divergent hydrophilic/hydrophobic properties on both sides of their interface. JMs have been exclusively used in the fields of fluid flow to induce unidirectional fluid transportation at the required interfaces. Herein, we report the fabrication of two Janus type bi-layer polymeric membranes with hydrophilic and hydrophobic surfaces on opposite sides using a simple doctor blading method. First bi-layer Janus membrane consists of polyvinylidene fluoride (PVDF) coating on cellulose cotton fabric (CPV). Second bi-layer Janus membrane (NPV) consists of partly hydrophilic nylon 6, 10 top layer and hydrophobic PVDF bottom layer. PVDF and nylon 6, 10 solutions are cast of a suitable thickness over the respective bottom layers. Prepared Janus membranes were characterised by SEM, FTIR and UV–Visible spectroscopy. Water contact angle measurements confirmed the hydrophilic and hydrophobic behaviour on opposite sides of the membranes. Porosity and equilibrium water content measurements established that both Janus membranes retain native properties of their constituent polymers. These newly engineered Janus type polymeric membranes could find potential application in creating unidirectional fluid flow transfer such as oil–water separations.

A typical combination of spiral wound ultra-filtration and spiral wound reverse-osmosis membranes were used to treat grey water obtained from washing machine discharge in order to recover the surfactant solution as well as water both of which could be reused for another couple of washes. The process leads to the separation of dirt and dust particles from the grey water using the UF process and later the surfactant solution and water is separated from the mixture using the reverse osmosis membrane. Various backwash and backwash-backflush methods were used to increase the membrane performance by decreasing the fouling problems which generally occurs in such types of membranes. These backwashing procedures were found to have enhanced the life of the membrane by cleaning the membranes. The TDS and turbidity of the solution mixtures were analyzed by conductivity meter and turbidity meter respectively and the results obtained from these instruments provided a good idea regarding the separation processes. The UF membranes could decrease the turbidity of a dirty mixture solution but allows the surfactant solution to pass though it which is finally treated using the RO membranes which could decrease both the turbidity and TDS of the solution. The experiment provides a comprehensive idea related to the treatment of grey water which could help in better waste water reuse as well as economic ways of reusing detergents for subsequent washes.

Reverse osmosis (RO) is the leading technology in desalination for both, brackish and seawater. Modeling RO process is a complex task as there are a high dependence on the operating conditions and feedwater characteristics. One of the main drawbacks of this technology is the performance decay due to fouling impact. Usually, fouling make the pressure drop to increase. This increase has not been reflected in the proposed models in RO process. The aim of this work was to proposed a time-dependent model for the pressure drop in RO process. For this purposes long-term experimental data of two full-scale brackish water RO desalination plants with two stages each were used. The first desalination plant was operating along 11 years in continuous regime while the second desalination plant was in operation during 14 years in intermittent regime. In the first desalination plant, the pressure drop ranges were 75-250 kPa and 25-150 kPa in the first and second stage respectively while in the second desalination plant were 50-200 kPa and 20-125 kPa. The behavior of the experimental data in both cases was close to an exponential function. The mentioned function was fitted in time domain using the standard deviation as error function.

This work demonstrates the use of baromembrane method based on reverse osmosis (RO) process. The method is realized on mobile complex, which allows to concentrate and determine ultra-low activity of radionuclides in water cooling ponds of Russian nuclear fuel cycle enterprises. The existence level of radionuclide background creates difficult conditions for identification the contribution of liquid discharges enterprise, as standard monitoring methods have a very high detection level for radionuclides. Traditional methods for determining the background radionuclides concentrations require the selection of at least 500 liters (l) of water, followed by their evaporation to form a dry residue. This procedure with RO membranes requires at least 5 days. It is possible to reduce the time and energy spent on evaporation of hundreds of water liters by pre-concentrating radionuclides in a smaller sample volume with baromembrane method. This approach allows preliminary concentration of water samples from 500 l volume till 20 l volume during several hours. This approach is universal for the concentration of dissolved salts of any heavy metals, other organic compounds and allows the preparation of water countable samples in much shorter time compared to the traditional evaporation method.

A low-pressure nitrogen plasma (LPNP) modified commercial thin-film composite membrane was used for pre-concentration of the clarified pomegranate juice (C-PJ) by reverse osmosis (RO). Pre-concentrates then submitted to osmotic distillation (OD) for further concentration. The productivity of the integrated membrane process was benchmarked considering both the performance and the final product quality. The modified RO membranes had great potential for shortening duration of consecutive concentration process, enabling up to 36% time saving during concentration of the C-PJ from 15.6 degrees Brix to >65 degrees Brix. Aroma losses observed in stand-alone OD are also prevented by shortening the duration of OD. Lower retention of malic acid, gallic acid, glucose, and fructose was observed due to the increased permeability following LPNP modification. However, these losses did not seem to affect the total acidity, total phenolic content, and total antioxidant activity of the concentrates obtained. The total color change was also in the range of barely noticeable values. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

This paper focuses on an analysis of the current situation of distillation and reverse osmosis technologies and their relationship with renewable energies, to the extent that there is a strong trend in the use of distillation and reverse osmosis technologies. Large-scale seawater desalination using renewable energy is not developed, so a detailed study of the combination of renewable energy facilities, reverse osmosis, and distillation systems are needed to be effective and competitive compared to the use nonrenewable energy. Solar multiple is a very important parameter in the solar thermal industry. This is in the range of 1.5 – 3 and depends on the relationship between storage and plant power. This parameter is important because it reflects a balance between the cost of the parabolic trough collectors and the total of the solar thermal plant. If the same criterion is followed, with a thermal gap of 100 °C, chosen for the parabolic trough collectors sizing, the solar multiple in the system object of this article, has a value higher than 3. The proposed system employs renewable energies for reducing the downtime of the desalination plants, doing possible that the desalination plants being competitive in sites with poor quality solar radiation.

Although the time-lag method is one of the most common tools for the characterization of gas permeation membranes, it is entirely unknown in the vast area of liquid permeation membranes. The time-lag method requires a dynamic permeation test initiated by a step-change in the driving force for the species permeation, which is relatively easy for gas permeation, but not for liquid permeation. In this paper, we present preliminary trials to overcome this obstacle for liquid permeation membranes by performing a sudden change in the osmotic pressure by changing the draw solution concentration. To accomplish this, we have modified a standard forward osmosis testing system to monitor the changes in the mass of feed and draw solutions, and the conductivity of feed solution in real-time. To demonstrate the system's operation, we tested commercial, low-pressure reverse osmosis thin film composite membranes in the active-layer-facing-draw-solution orientation. We present and discuss the resulting time-dependent changes in the water flux and the reverse salt flux, and the processing of the experimental data. The shapes of time-dependent water and salt masses are similar to the pressure decay curves and pressure rise curves, respectively, in a time-lag gas permeation experiment.

The shortage of potable water, especially in developing countries has attracted researchers to try and overcome this problem. Desalination is one of the most effective methods used to solve this problem. Among desalination techniques, Reverse Osmosis (RO) has higher priority than thermal desalination methods, on account of its comparatively limited energy consumption. Different methods were introduced to enhance the performance of RO desalination plants. This study focused on employing an Energy Recovery System (ERS) to enhance the performance of the small RO plant for remote areas. The unit capacity was 2.4 m3/day, occupied with two double-acting cylinders with their control elements working as an ERS. An experimental setup is used to verify the effectiveness of the proposed ERS. A simulation model is designed and implemented to enable changing system parameters of the plant. The different system pressure experimental and model results were exposed and compared. The obtained results showed good agreement between experimental and simulation model values. The effect of recovery ratio on the power saving is highlighted. The ERS saved power consumption by 80%. The cost analysis of the small RO desalination plant with and without ERS was evaluated and showed a significant reduction in total cost.

A submerged photocatalytic membrane reactor (SPMR) was used with suspended and immobilized N–TiO2 under visible irradiation for diclofenac (DCF) removal from wastewater. The effects of initial N–TiO2 concentrations for the SPMR with suspended N–TiO2 were determined for batch processes. Hydrogen peroxide was also coupled with the photocatalytic process. In continuous conditions, a reverse osmosis (RO) membrane was combined with the SPMR for enhancing effluent quality. DCF removal by the SPMR with suspended and immobilized N–TiO2 at a low N–TiO2 dosage (0.5 g/L) was not much different between the two systems, but increased with higher N–TiO2 dosages for the reactor with suspended N–TiO2. Coupling H2O2 with the photocatalytic process under visible irradiation enhanced the DCF removal efficiency. In continuous conditions, DCF concentrations in the photoreactor increased during the reaction time, while those in the effluent (RO permeate) were steady for both systems and both processes. The permeate flux in the reactor with suspended N–TiO2 declined faster than in the reactor with the immobilized N–TiO2. Coupling H2O2 with the photocatalytic process yielded more resistant permeate flux rates. The cake layer formed on the microfiltration membrane of the SPMR with suspended N–TiO2 under visible irradiation was denser than others after completing the process.

The review covers the hydrodynamic and physico-chemical aspects of a number of inter-related situations arising in relation to flows in the individual nanochannels and microchannels or in the interconnected networks of microscopic pores inside membranes formed by electrospun nanofibers. The applications of such flows or devices comprised of such elements are discussed too, having in mind reverse osmosis, cooling of high-power microelectronics by means of nanoparticles of phase-change materials, charging oils in electrostatic atomizers, printing wearable microelectronics on textiles, separators, and forensic science. Such flows can be also used for non-specific adsorption of heavy metal ions on biopolymer-containing membranes, and scavenging of nanoparticles from throughflows by means of the van der Waals or Coulombic forces. Microchannel flows inside the inter-connected pores of electrospun membranes can be electrokinetically driven as the electro-osmotic Smoluchowski flows, which opens a way to malleable membranes and surfaces. They also can be thermo-responsive or pH-responsive in the case of membranes formed from PNIPAM and poly(N-isopropyl acrylamide) electrospun nanofibers, which yield novel actuators and drug carriers.

Summary Desalination technologies, which remove solutes from water, are essential to the purification of water for agricultural and industrial purposes and for potable use. While a variety of desalination technologies exist, their performance and durability need improvements to meet future clean water demands. This challenge is particularly complex as a variety of feed water sources exists, which contain various amounts of salt, dissolved organic matter, suspended particulates, and other contaminants. Hence, predictive knowledge of the underlying physics and chemistry at the atomic and molecular scale is crucial for designing improved desalination materials and processes. In this Perspective, we outline how advanced characterization techniques, including X-ray, neutron, electron-based, and positron-based methods can be advantageously applied to water desalination technologies to provide detailed molecular insight, especially when combined with computational modeling. We summarize some of the scientific challenges in two prominent desalination techniques, membrane reverse osmosis and capacitive deionization, and lay out some specific approaches toward solving these challenges. With these developments, we anticipate that the use of advanced characterization can help advance the field of water desalination in much the same way that these have aided progress in energy storage and conversion science over the last decades.

Experimental tests of a small polygeneration plant unit based on hybrid renewable energy and desalination have been used to validate a novel model simulation of this plant. It provides electricity by coupling photovoltaic/thermal collectors and a micro-wind turbine, fresh water by means of hybrid desalination (membrane distillation, and reverse osmosis), and sanitary hot water coming from the photovoltaic/thermal collectors and an evacuated tubes collector. Plant was designed to operate in off-grid conditions and conventional energy storage systems were used (lead acid batteries and hot water tank). Simulation model was performed in TRNSYS environment and it was fully validated by comparing several key plant measurements. The analysis was focused on five typical days of summer, fall and winter. Some differences found in experimental and simulated values were analysed. To reduce those gaps, some modifications have been suggested to the model or the pilot unit respectively. As a result, a validated model in TRNSYS of the plant was obtained. This model can be used for the further scale up of new projects to cover any other scheduled demands of power and water in isolated areas, whenever is based on the combination of the abovementioned technologies.