Solute Diffusion Research Articles

Application of Bernoulli wavelet method on triple‐diffusive convection in Jeffery–Hamel flow

AbstractIn this article, triple‐diffusive convection in the Jeffery–Hamel flow of viscous fluid is studied. The Jeffery–Hamel flow depends upon the radial component of velocity, while the peripheral velocity is zero. The problem has been articulated as nonlinear coupled partial differential equations (PDEs) together with the pertinent boundary conditions. The reduction of the nonlinear coupled PDEs into new nonlinear coupled ordinary differential equations is achieved via a collection of appropriate transformations, which is solved using the Bernoulli wavelet method. The obtained results were compared with the numerical results, confirming the good agreement between the present and previous numerical results. Dimensionless velocity, temperature, and concentration profiles are discussed for the relevant factors involved. Furthermore, skin friction, heat transfer, and solute diffusions are calculated.

Natural extract-polymer monodisperse submicron particles from Plateau-Rayleigh microjets

Particles of interest in food, pharmaceutical, and nutraceutical sectors are often formulated with a polymer and one or more natural or synthetic active compound. The two components frequently have distinct hydrophilicity. Submicrometric particles with narrow size dispersion can be made by the droplet-to-particle route by electrospray. In the steady cone-jet mode a liquid Taylor cone (TC) continuously emits a Plateau-Rayleigh microjet which breaks up spontaneously and periodically into tiny droplets, which later dry up to form solid particles. To achieve a stable process of this kind, we argue that it is necessary to: (i) operate near the minimum solution flow rate compatible with TC stability, (ii) prevent the drying of the TC by surrounding it with a gentle gas stream saturated in solvent vapor, and (iii) monitor the electric current and image the TC. We demonstrate this process in the preparation of curcumin (CUR) loaded polyvinylpyrrolidone (PVP) submicrometric particles as a function of solution composition and ambient relative humidity. In the atomization step (jet and droplet formation), the initial droplet size and charge are determined by the liquid properties and flow rate. The particles’ shapes were spherical (with or without internal voids), corrugated due to shell buckling (with compact interiors), and filamented due to Coulombic instabilities, depending on the interplay of different factors at the droplet drying step. These included the droplet size and charge, solvent evaporation, solute diffusion, water uptake from the ambient, mechanical forces, and solution thermodynamics. The electric current and droplet size are suitably predicted by scaling laws developed for simple Newtonian fluids. Hence, our particle sizes lie always between the predicted droplet and compact-sphere sizes, at a distance which depends on the particle morphology. CUR-loaded PVP quasi-monodisperse submicron particles could be an interesting model for drug delivery and biomedical applications.

Enhancement of solute diffusion in microdroplets using microrotors under rotational magnetic field

In vertical contact control (VCC), a microdroplet array selectively contacts with an opposite microdroplet array. Generally, VCC is useful for the dispenser mechanism based on solute diffusion between microdroplet pairs. However, sedimentation due to gravity can cause an inhomogeneous distribution of solutes in microdroplets. Therefore, it is necessary to enhance solute diffusion to achieve the accurate dispensing of a large quantity of solute in the direction opposite to that of gravity. Herein, we applied a rotational magnetic field to the microrotors in microdroplets to enhance the solute diffusion in microdroplets. Driven by microrotors, the rotational flow can generate a homogeneous distribution of solutes in microdroplets. We analyzed the diffusion dynamics of solutes using a phenomenological model, and the results showed that the rotation of microrotors can increase the diffusion constant of solutes.

Electrostatic hindrance to diffusion in flexible crosslinked gels: A coarse-grained simulation study.

In this work, we study how electrostatic forces slow down the diffusion of solute in flexible gels through coarse-grained simulations. The model used explicitly considers the movement of solute particles and polyelectrolyte chains. These movements are performed by following a Brownian dynamics algorithm. The effect of three electrostatic parameters characterizing the system (solute charge, polyelectrolyte chain charge, and ionic strength) is analyzed. Our results show that the behavior of both the diffusion coefficient and the anomalous diffusion exponent changes upon the reversal of the electric charge of one of the species. In addition, the diffusion coefficient in flexible gels differs significantly from that in rigid gels if the ionic strength is low enough. However, the effect of chain flexibility on the exponent of anomalous diffusion is significant even at high ionic strength (100 mM). Our simulations also prove that varying the polyelectrolyte chain charge does not have exactly the same effect as varying the solute particle charge.

Robust estimates of solute diffusivity in polymers for predicting patient exposure to medical device leachables

AbstractMedical devices often include polymeric components, which contain additives or contaminants that may leach into patients and pose a health risk. Previously, we proposed a mass transport model that conservatively estimates the leaching kinetics and only requires the solute's diffusion coefficient in the polymer, , to be specified. Because determining experimentally is time‐consuming, we also parameterized empirical models to estimate worst‐case values using only the solute molecular weight, . These models were based on a modest database and were limited to 19 polymers and larger solutes ( g/mol). Here, we assemble a much larger database, which enables us to construct more accurate models using a robust statistical approach, expanding the coverage to 50 device‐relevant polymers and smaller solutes ( g/mol). Then, we demonstrate several applications of these bounds, including modeling the release kinetics. Finally, we observe an interesting phenomenon, a discontinuous drop in of up to 25,000× for solutes with g/mol in glassy polymers. Using molecular simulations and cheminformatics tools, we propose a novel definition of the effective diameter of free volume channels in polymers, and we show that solutes larger than this channel size diffuse much more slowly.

Linking Soil Structure, Hydraulic Properties, and Organic Carbon Dynamics: A Holistic Framework to Study the Impact of Climate Change and Land Management

AbstractClimate change and unsustainable land management practices have resulted in extensive soil degradation, including alteration of soil structure (i.e., aggregate and pore size distributions), loss of soil organic carbon, and reduction of water and nutrient holding capacities. Although soil structure, hydrologic processes, and biogeochemical fluxes are tightly linked, their interaction is often unaccounted for in current ecohydrological, hydrological and terrestrial biosphere models. For more holistic predictions of soil hydrological and biogeochemical cycles, models need to incorporate soil structure and macroporosity dynamics, whether in a natural or agricultural ecosystem. Here, we present a theoretical framework that couples soil hydrologic processes and soil microbial activity to soil organic carbon dynamics through the dynamics of soil structure. In particular, we link the Millennial model for soil carbon dynamics, which explicitly models the formation and breakdown of soil aggregates, to a recent parameterization of the soil water retention and hydraulic conductivity curves and to solute and O2 diffusivities to soil microsites based on soil macroporosity. To illustrate the significance of incorporating the dynamics of soil structure, we apply the framework to a case study in which soil and vegetation recover over time from agricultural practices. The new framework enables more holistic predictions of the effects of climate change and land management practices on coupled soil hydrological and biogeochemical cycles.

Supervivencia y su relación con el tipo de transferencia de solutos de membrana peritoneal, en pacientes con enfermedad renal crónica incidentes en terapia de diálisis peritoneal en RTS Colombia entre los años 2007-2017

IntroductionIn some studies, the peritoneal solute transfer rate (PSTR) through the peritoneal membrane has been related to an increased risk of mortality. It has been observed in the literature that those patients with rapid diffusion of solutes through the peritoneal membrane (high/fast transfer) and probably those with high average transfer characterized by the peritoneal equilibrium test (PET) are associated with higher mortality compared to those patients who have a slow transfer rate. However, some authors have not documented this fact. In the present study, we want to evaluate the (etiological) relationship between the characteristics of peritoneal membrane transfer and mortality and survival of the technique in an incident population on peritoneal dialysis in RTS Colombia during the years 2007 to 2017 using a competing risk model. Materials and methodsA retrospective cohort study was carried out at RTS Colombia in the period between 2007 and 2017. In total, there were 8170 incident patients older than 18 years, who had a PET between 28 and 180 days from the start of therapy. Demographic, clinical, and laboratory variables were evaluated. The (etiological) relationship between the type of peritoneal solute transfer rate at the start of therapy and overall mortality and technique survival were analyzed using a competing risk model (cause-specific proportional hazard model described by Royston-Lambert). ResultsPatients were classified into four categories based on the PET result: slow/low transfer (16.0%), low average (35.4%), high average (32.9%), and high/fast transfer (15.7%). During follow-up, with a median of 730 days, 3025 (37.02%) patients died, 1079 (13.2%) were transferred to hemodialysis and 661 (8.1%) were transplanted. In the analysis of competing risks, adjusted for age, sex, presence of DM, HTA, body mass index, residual function, albumin, hemoglobin, phosphorus, and modality of PD at the start of therapy, we found cause-specific HR (HRce) for high/fast transfer was 1.13 (95% CI 0.98–1.30) P = .078, high average 1.08 (95% CI 0.96–1.22) P = .195, low average 1.09 (95% CI 0.96–1.22) P = .156 compared to the low/slow transfer rate. For technique survival, cause-specific HR for high/rapid transfer of 1.22 (95% CI 0.98–1.52) P = .66, high average HR was 1.10 (95% CI 0.91–1.33) P = .296, low average HR of 1.03 (95% CI 0.85–1.24) P = .733 compared with the low/slow transfer rate, adjusted for age, sex, DM, HTA, BMI, residual renal function, albumin, phosphorus, hemoglobin, and PD modality at start of therapy. Non-significant differences. ConclusionsWhen evaluating the etiological relationship between the type of peritoneal solute transfer rate and overall mortality and survival of the technique using a competing risk model, we found no etiological relationship between the characteristics of peritoneal membrane transfer according to the classification given by Twardowski assessed at the start of peritoneal dialysis therapy and overall mortality or technique survival in adjusted models. The analysis will then be made from the prognostic model with the purpose of predicting the risk of mortality and survival of the technique using the risk subdistribution model (Fine & Gray).

Single-Molecule Fluorescence Investigations of Solute Transport Dynamics in Nanostructured Membrane Separation Materials.

Many materials used for membrane separations are composed of nanoscale structures such as pores and domains. Such nanostructures often control the solute permeability and selectivity of the separation membranes. Thus, for future development of highly efficient separation membranes, it is important to understand the structural and chemical properties of these nanostructures and also their influences on solute transport dynamics. For the last two decades, single-molecule fluorescence techniques have been used to measure the detailed dynamics of solute molecules diffusing in various nanostructured materials, giving valuable insights into molecular transport mechanisms influenced by nanoscale material heterogeneity. This Perspective discusses recent single-molecule fluorescence studies on solute diffusion in materials relevant to membrane separations, including dense polymer films and nanoporous materials. These studies have revealed the formation and properties of nanostructures and unique transport dynamics of solute molecules manipulated by their confinement and partitioning to the nanostructures, which play key roles in membrane separations. This Perspective will also point out scientific challenges toward a thorough understanding of molecular-level mechanisms in membrane separations.

Critical Analysis of Published Physical Property Data for Aqueous Potassium Hydroxide. Collation into Detailed Models for Alkaline Electrolysis

Physical properties of aqueous KOH solutions are crucial to the design and operation of alkaline electrolyzers but have been scarcely and sometimes unreliably reported. Obtaining published data for various properties currently requires time-consuming searches and subsequent interpretation, interpolation, and extrapolation. This work collates and critically analyzes published data for a range of physical properties relevant to alkaline electrolysis, including the density, viscosity, conductivity, surface tension, oxygen/hydrogen solubility, oxygen/hydrogen diffusivity, and water vapor pressures of aqueous KOH solutions, as a function of temperature, KOH molarity, and pressure. Correlation functions, in the form of excel spreadsheets, have been developed to allow interpolation of the most reliable data and computation of desired quantities at specific temperatures, pressures, and KOH concentrations. Composite models incorporating these properties have been developed for automated computation of (i) diffusive gas crossover and (ii) gas production volumes, including (iii) water vapor content, and associated (iv) dissolved gas concentrations in the liquid electrolyte, as a function of KOH concentration, temperature, pressure, current density, and separator thickness and porosity. These spreadsheets are provided in the Supporting Information, as tools and reference points for researchers and practitioners in alkaline electrolysis.

Printable Hydrogel Arrays for Portable and High-Throughput Shear-Mediated Assays.

Hydrogels have been widely used to entrap biomolecules for various biocatalytic reactions. However, solute diffusion in these matrices to initiate such reactions can be a very slow process. Conventional mixing remains a challenge as it can cause irreversible distortion or fragmentation of the hydrogel itself. To overcome the diffusion-limit, a shear-stress-mediated platform named the portable vortex-fluidic device (P-VFD) is developed. P-VFD is a portable platform which consists of two main components, (i) a plasma oxazoline-coated polyvinyl chloride (POx-PVC) film with polyacrylamide and alginate (PAAm/Alg-Ca2+) tough hydrogel covalently bound to its surface and (ii) a reactor tube (L × D: 90 mm × 20 mm) where the aforementioned POx-PVC film could be readily inserted for reactions. Through a spotting machine, the PAAm/Alg-Ca2+ hydrogel can be readily printed on a POx-PVC film in an array pattern and up to 25.4 J/m2 adhesion energy can be achieved. The hydrogel arrays on the film not only offer a strong matrix for entrapping biomolecules such as streptavidin-horseradish peroxidase but are also shear stress-tolerant in the reactor tube, enabling a >6-fold increase in its reaction rate after adding tetramethylbenzidine, relative to incubation. Through using the tough hydrogel and its stably bonded substrate, this portable platform effectively overcomes the diffusion-limit and achieves fast assay detection without causing appreciable hydrogel array deformation or dislocation on the substrate film.

Modeling Segregation of Fe–C Alloy in Solidification by Phase-Field Method Coupled with Thermodynamics

The primary carbide in high carbon chromium bearing steels, which arises from solute segregation during non-equilibrium solidification, is one of the key factors affecting the mechanical properties and performance of the related components. In this work, the effects of carbide forming element diffusion, primary austenite grain size, and the cooling rate on solute segregation and carbide precipitation during the solidification of an Fe–C binary alloy were studied by the phase-field method coupled with a thermodynamic database. It was clarified that increasing the ratio of solute diffusivity in solid and liquid, refining the grain size of primary austenite to lower than a critical value, and increasing the cooling rate can reduce the solute segregation and precipitation of primary carbide at late solidification. Two characteristic parameters were introduced to quantitatively evaluate the solute segregation during solidification including the phase fraction threshold of primary austenite when the solute concentration in liquid reaches the eutectic composition, and the maximum segregation ratio. Both parameters can be well-correlated to the ratio of solute diffusivity in solid and liquid, the grain size of primary austenite, and the cooling rate, which provides potential ways to control the solute segregation and precipitation of primary carbide in bearing steels.

Forward-Reverse Osmosis Processes for Oily Wastewater Treatment

In this study, the feasibility of Forward–Reverse osmosis processes was investigated for treating the oily wastewater. The first stage was applied forward osmosis process to recover pure water from oily wastewater. Sodium chloride (NaCl) and magnesium chloride (MgCl2) salts were used as draw solutions and the membrane that was used in forward osmosis (FO) process was cellulose triacetate (CTA) membrane. The operating parameters studied were: draw solution concentrations (0.25 – 0.75 M), oil concentration in feed solution (FS) (100-1000 ppm), the temperature of FS and draw solution (DS) (30 - 45 °C), pH of FS (4-10) and the flow rate of both DS and FS (20 - 60 l/h). It was found that the water flux and oil concentration in FS increase by increasing the concentration of draw solutions, the flow rate of FS and the temperature for a limit (40oC), then, the water flux and oil concentration decrease with increasing the temperature because of happening the internal concentration polarization phenomenon. By increasing the oil concentration in FS and the flow rate of the DS, the water flux and oil concentration in FS decreased, while it had a fluctuated behavior with increasing pHof oily wastewater. It was found also that MgCl2 gives water flux higher than NaCl. So the values of resistance to solute diffusion within the membrane porous support layer were 55.93 h/m and 26.21 h/m for NaCl and MgCl2 respectively. The second stage was applied reverse osmosis process using polyamide (thin film composite (TFC)) membrane for separating the fresh water from a diluted (NaCl) solution using different parameters such as draw solution concentration (0.08–0.16 M), feed flow rate (20–40 l/h).

Radiation absorption impact on the thermophysical properties of Cu- and TiO2-water nanofluids: Laplace transform technique

An electrically conducting time-dependent flow of water-based nanofluid comprised of Copper and Titanium oxide over a stationary plate embedding with a porous matrix is analyzed in this study. The novelty arises due to the interaction of both the thermal radiation as well as the radiation absorption that affect the heat transport phenomenon. In the single-phase flow, both the variation of particle concentration and the solutal concentration for the inclusion of chemical reaction are taken care of. Also, the influence of the free convection phenomena is explained significantly. The transformed dimensionless system of the governing equations is handled analytically by using the Laplace Transform method. The behavior of the characterizing parameters involved in the governing equations is presented via graphs and the simulation of the numerical results of the rate coefficients like shear rate and rate of heat and solutal transfer is deployed through the table. However, the physical significance of these parameters is deliberated briefly. Finally, the important outcomes are higher heavier species because of lesser solutal diffusivity which attenuates the fluid concentration throughout the domain. Further, radiation absorption causes a significant boost in the nanofluid temperature distribution.

Laponite nanoclay-modified sacrificial composite ink for perfusable channel creation via embedded 3D printing

Vascularization is a major hurdle in developing in vitro thick tissue constructs. Fortunately, embedded sacrificial printing has emerged as a promising technology to fabricate perfusable channels. The objective of this study is to develop a Laponite nanoclay-modified polyvinyl alcohol (PVA) sacrificial composite ink that has improved printability, minimized interdiffusivity, and satisfactory post-printing removability during embedded printing of perfusable channels. With the addition of Laponite nanoclay, not only the printability of the PVA-Laponite nanoclay composite ink is significantly improved, but also the interdiffusion between the gelatin precursor solution and the PVA-Laponite nanoclay composite ink is largely mitigated. The diffusion of the gelatin precursor solution into the PVA-Laponite nanoclay composite ink is of great importance for printing controllable perfusable channels since the diffused gelatin may cross-link as the gelatin composite matrix does during and after printing, resulting in residual gelatin gel in the channel and altered channel dimensions. In particular, the PVA-2.0% Laponite nanoclay sacrificial ink shows good printability and minimized interdiffusivity while maintaining good post-printing removability, which can be a good sacrificial composite ink for thick perfusable tissue creations. The channel diameter reduction due to the gelatin solution diffusion can be satisfactorily predicted based on the unidirectional diffusion model. This study further demonstrates the feasibility of using the proposed sacrificial ink for vascular tissue engineering applications.

Disentangling the impact of cerebrospinal fluid formation and neuronal activity on solute clearance from the brain

BackgroundDespite recent attention, pathways and mechanisms of fluid transposition in the brain are still a matter of intense discussion and driving forces underlying waste clearance in the brain remain elusive. Consensus exists that net solute transport is a prerequisite for efficient clearance. The individual impact of neuronal activity and cerebrospinal fluid (CSF) formation, which both vary with brain state and anesthesia, remain unclear.MethodsTo separate conditions with high and low neuronal activity and high and low CSF formation, different anesthetic regimens in naive rat were established, using Isoflurane (ISO), Medetomidine (MED), acetazolamide or combinations thereof. With dynamic contrast-enhanced MRI, after application of low molecular weight contrast agent (CA) Gadobutrol to cisterna magna, tracer distribution was monitored as surrogate for solute clearance. Simultaneous fiber-based Ca2+-recordings informed about the state of neuronal activity under different anesthetic regimen. T2-weighted MRI and diffusion-weighted MRI (DWI) provided size of subarachnoidal space and aqueductal flow as surrogates for CSF formation. Finally, a pathway and mechanism-independent two-compartment model was introduced to provide a measure of efficiency for solute clearance from the brain.ResultsAnatomical imaging, DWI and Ca2+-recordings confirmed that conditions with distinct levels of neuronal activity and CSF formation were achieved. A sleep-resembling condition, with reduced neuronal activity and enhanced CSF formation was achieved using ISO+MED and an awake-like condition with high neuronal activity using MED alone. CA distribution in the brain correlated with the rate of CSF formation. The cortical brain state had major influence on tracer diffusion. Under conditions with low neuronal activity, higher diffusivity suggested enlargement of extracellular space, facilitating a deeper permeation of solutes into brain parenchyma. Under conditions with high neuronal activity, diffusion of solutes into parenchyma was hindered and clearance along paravascular pathways facilitated. Exclusively based on the measured time signal curves, the two-compartment model provided net exchange ratios, which were significantly larger for the sleep-resembling condition than for the awake-like condition.ConclusionsEfficiency of solute clearance in brain changes with alterations in both state of neuronal activity and CSF formation. Our clearance pathway and mechanism agnostic kinetic model informs about net solute transport, solely based on the measured time signal curves. This rather simplifying approach largely accords with preclinical and clinical findings.

Redefining a traditional membrane modelling approach

The traditional solution–diffusion model, long used for studying water transport in reverse osmosis membranes, is re-evaluated with molecular dynamics simulations.

Cations impact radical reaction dynamics in concentrated multicomponent aqueous solutions.

Ultraviolet (UV) photolysis of nitrite ions (NO2-) in aqueous solutions produces a suite of radicals, viz., NO·, O-, ·OH, and ·NO2. The O- and NO· radicals are initially formed from the dissociation of photoexcited NO2-. The O- radical undergoes reversible proton transfer with water to generate ·OH. Both ·OH and O- oxidize the NO2- to ·NO2 radicals. The reactions of ·OH occur at solution diffusion limits, which are influenced by the nature of the dissolved cations and anions. Here, we systematically varied the alkali metal cation, spanning the range from strongly to weakly hydrating ions, and measured the production of NO·, ·OH, and ·NO2 radicals during UV photolysis of alkaline nitrite solutions using electron paramagnetic resonance spectroscopy with nitromethane spin trapping. Comparing the data for the different alkali cations revealed that the nature of the cation had a significant effect on production of all three radical species. Radical production was inhibited in solutions with high charge density cations, e.g., lithium, and promoted in solutions containing low charge density cations, e.g., cesium. Through complementary investigations with multinuclear single pulse direct excitation nuclear magnetic resonance (NMR) spectroscopy and pulsed field gradient NMR diffusometry, cation-controlled solution structures and extent of NO2- solvation were determined to alter the initial yields of ·NO and ·OH radicals as well as alter the reactivity of NO2- toward ·OH, impacting the production of ·NO2. The implications of these results for the retrieval and processing of low-water, highly alkaline solutions that comprise legacy radioactive waste are discussed.

Brain Endothelial Cells Play a Central Role in the Development of Enlarged Perivascular Spaces in the Metabolic Syndrome.

Brain capillary endothelial cell(s) (BECs) have numerous functions, including their semipermeable interface-barrier (transfer and diffusion of solutes), trophic (metabolic homeostasis), tonic (vascular hemodynamics), and trafficking (vascular permeability, coagulation, and leukocyte extravasation) functions to provide brain homeostasis. BECs also serve as the brain's sentinel cell of the innate immune system and are capable of antigen presentation. In metabolic syndrome (MetS), there are two regions resulting in the proinflammatory signaling of BECs, namely visceral adipose tissue depots supplying excessive peripheral cytokines/chemokines (pCCs) and gut microbiota dysbiotic regions supplying excessive soluble lipopolysaccharide (sLPS), small LPS-enriched extracellular vesicle exosomes (lpsEVexos), and pCCs. This dual signaling of BECs at their receptor sites results in BEC activation and dysfunction (BECact/dys) and neuroinflammation. sLPS and lpsEVexos signal BECs' toll-like receptor 4, which then signals translocated nuclear factor kappa B (NFkB). Translocated NFkB promotes the synthesis and secretion of BEC proinflammatory cytokines and chemokines. Specifically, the chemokine CCL5 (RANTES) is capable of attracting microglia cells to BECs. BEC neuroinflammation activates perivascular space(s) (PVS) resident macrophages. Excessive phagocytosis by reactive resident PVS macrophages results in a stagnation-like obstruction, which along with increased capillary permeability due to BECact/dys could expand the fluid volume within the PVS to result in enlarged PVS (EPVS). Importantly, this remodeling may result in pre- and post-capillary EPVS that would contribute to their identification on T2-weighted MRI, which are considered to be biomarkers for cerebral small vessel disease.

Microstructural Evolution and Mechanical Properties of SiC/Al-40Si Composites Fabricated by High Pressure Solidification.

The microstructure and mechanical properties of SiC/Al-40Si composites prepared under high pressure were studied. As the pressure increases from 1 atm to 3 GPa, the primary Si phase in the Al-40Si alloy is refined. With increasing pressure, the composition of the eutectic point increases, the solute diffusion coefficient decreases exponentially, and the concentration of Si solute at the front of the solid-liquid interface of the primary Si is low, which contributes to the refining of the primary Si and inhibiting its faceted growth. The bending strength of SiC/Al-40Si composite prepared under 3 GPa was 334 MPa, which was 66% higher compared to the Al-40Si alloy prepared under the same pressure.

The Potential of Multi-stage Pressure Retarded Osmosis for Blue Energy Harvesting

Objective: This study aims to investigate the potential benefits of using different multi-stage and multi-pass flow configurations for improving the efficiency of the pressure-retarded osmosis (PRO) process, which generates energy by utilizing the difference in osmotic pressure between two salinity solutions. Methods: To achieve the objective, the study used a numerical simulation based on the solution diffusion model. A flat sheet forward osmosis membrane was simulated to investigate the potential of the proposed multi-stage PRO configurations. Results: The results of the simulation showed that the multi-stage PRO arrangement generated 18% more power than the single-stage PRO system. Additionally, the multi-pass arrangement resulted in a 58% increase in power output. Conclusion: This study provides important insights into the development of optimized PRO membrane and module configurations to improve the efficiency of energy generation. The findings highlight the potential benefits of multi-stage and multi-pass flow configurations, which can help to advance the field of renewable energy generation using the PRO process.