Showing papers on "Forward osmosis published in 2011"
TL;DR: In this article, a thin film composite (TFC) polyamide forward osmosis (FO) membranes with tailored support structure were prepared via phase inversion, and the polyamide rejection layers were synthesized by interfacial polymerization.
528 citations
TL;DR: A theoretical model to predict the water flux in pressure retarded osmosis, from which the power density that can be achieved by a membrane is predicted, is presented, the first to incorporate external concentration polarization, a performance limiting phenomenon that becomes significant for high-performance membranes.
Abstract: Pressure retarded osmosis has the potential to produce renewable energy from natural salinity gradients. This work presents the fabrication of thin-film composite membranes customized for high performance in pressure retarded osmosis. We also present the development of a theoretical model to predict the water flux in pressure retarded osmosis, from which we can predict the power density that can be achieved by a membrane. The model is the first to incorporate external concentration polarization, a performance limiting phenomenon that becomes significant for high-performance membranes. The fabricated membranes consist of a selective polyamide layer formed by interfacial polymerization on top of a polysulfone support layer made by phase separation. The highly porous support layer (structural parameter S = 349 μm), which minimizes internal concentration polarization, allows the transport properties of the active layer to be customized to enhance PRO performance. It is shown that a hand-cast membrane that bal...
503 citations
TL;DR: In this paper, the results on the commonly used chemical fertilizers as FO draw solution were reported based on the currently available FO tech- nology, about nine commonly used fertilizers were finally screened from a comprehensive list of fertilizers and their performances were assessed in terms of pure water flux and reverse draw solute flux.
404 citations
TL;DR: Forward osmosis (FO) is a well-recognized osmotic process for producing clean water because of the low energy input and has great potential for various applications including wastewater reclamation, seawater desalination, and energy production.
Abstract: Clean water shortage is one of the biggest global crises. [ 1 ] Thus clean water production and regeneration have become the main concerns. Among a variety of technologies, forward osmosis (FO) is a well-recognized osmotic process for producing clean water because of the low energy input, [ 2 ] as shown in Figure S1 (Supporting Information). Driven by osmotic pressure gradient ( Δ π ) across a semipermeable FO membrane, water diffuses naturally through the membrane, leaving impurities behind. This process has great potential for various applications including wastewater reclamation, [ 3 ] seawater desalination, [ 4 ] and energy production. [ 5 ]
368 citations
TL;DR: In this article, the support layers of two commercially available thin film composite reverse osmosis membranes were modified to enhance their hydrophilicity, which resulted in an increase in the porosity and reduced internal concentration polarization.
317 citations
TL;DR: In this article, the authors proposed a novel thin film composite membrane for engineered osmosis (EO), which comprises an electrospun polymeric nanofiber support layer and a polyamide skin layer formed by in situ polymerization.
296 citations
TL;DR: Ionic polymer hydrogels with thermal responsive units are found to induce higher water permeation rates in the osmosis process, and higher water release rates under a combination of pressure and thermal stimuli.
295 citations
TL;DR: In this paper, the authors investigated the physical and chemical parameters affecting forward osmosis flux performance during microalgae separation and reported that the presence of Mg 2+ in the feed water had detrimental effect on algal fouling.
294 citations
TL;DR: This study demonstrates that by thoughtful selection of the membrane properties and hydrodynamic conditions, the detrimental effects that limit productivity in a pressure retarded osmosis power generation process can be methodically minimized to achieve high performance.
Abstract: Pressure retarded osmosis has the potential to utilize the free energy of mixing when fresh river water flows into the sea for clean and renewable power generation. Here, we present a systematic investigation of the performance limiting phenomena in pressure retarded osmosis—external concentration polarization, internal concentration polarization, and reverse draw salt flux—and offer insights on the design criteria of a high performance pressure retarded osmosis power generation system. Thin-film composite polyamide membranes were chemically modified to produce a range of membrane transport properties, and the water and salt permeabilities were characterized to determine the underlying permeability-selectivity trade-off relationship. We show that power density is constrained by the trade-off between permeability and selectivity of the membrane active layer. This behavior is attributed to the opposing influence of the beneficial effect of membrane water permeability and the detrimental impact of reverse sa...
290 citations
TL;DR: A new approach to fabricate thin film composite (TFC) membranes via interfacial polymerization for forward osmosis (FO) applications has revealed that it is possible to design TFC-FO membranes with fully sponge-like structure and likely anti-fouling characteristics while maintaining a high water flux.
285 citations
TL;DR: Five emerging applications of forward osmosis that elegantly bypass the difficult step of draw solution regeneration and make common processes more sustainable are highlighted.
Abstract: Many conventional practices in the production and use of water, energy, and food are unsustainable. Existing technologies and concepts can be improved with the integration of forward osmosis, a membrane-based technology that uses osmosis as its driving force. This Feature highlights five emerging applications of forward osmosis that elegantly bypass the difficult step of draw solution regeneration and make common processes more sustainable. These applications enhance the efficiency of the production and use of water, energy, and food; utilize wastes and abundant, low value resources; and better protect the environment.
TL;DR: In this article, forward osmosis (FO) was used to reduce the energy consumption of indirect desalination and extract water from impaired sources by using a secondary wastewater effluent as feed water and Red Sea water as a draw solution.
TL;DR: Novel nanofiltration (NF)-like FO membranes with good magnesium chloride retention were synthesized using layer-by-layer (LbL) assembly using high porosity, finger-like pores, thin cross-section, and high hydrophilicity to achieve a small structural parameter of 0.5 mm.
Abstract: Forward osmosis (FO) has received considerable interest for water- and energy-related applications in recent years. FO does not require an applied pressure and is believed to have a low fouling tendency. However, a major challenge in FO is the lack of high performance FO membranes. In the current work, novel nanofiltration (NF)-like FO membranes with good magnesium chloride retention were synthesized using layer-by-layer (LbL) assembly. The membrane substrate was tailored (high porosity, finger-like pores, thin cross-section, and high hydrophilicity) to achieve a small structural parameter of 0.5 mm. Increasing the number of polyelectrolyte layers improved the selectivity of the LbL membranes while reducing their water permeability. The more selective membrane 6#LbL (with 6 polyelectrolyte layers) had much lower reverse solute transport compared to 3#LbL and 1#LbL. Meanwhile, the FO water flux was found to be strongly affected by both membrane water permeability and solute reverse transport. Severe solute...
TL;DR: In this paper, the authors used asymmetric microporous hollow fibers made of Torlon® polyamide-imide (PAI) material as the porous substrate followed by polyelectrolyte post-treatment using polyethyleneimine (PEI), which has not been reported previously.
TL;DR: In this article, a series of poly(ethylene glycol)diacid-coated (PEG−(COOH)2)-coated magnetic nanoparticles with different size distributions have been synthesized by means of the thermal decomposition method.
Abstract: Forward osmosis (FO) is an emerging technology for desalination and water reuse. However, a big challenge is finding suitable draw solutes. In this work, we have synthesized magnetic nanoparticles (MNPs), investigated their potential as draw solutes in FO systems, and explored their recovery and reusability. A series of poly(ethylene glycol)diacid-coated (PEG−(COOH)2-coated) MNPs with different size distributions have been synthesized by means of the thermal decomposition method. The physical properties and chemical compositions of the resultant MNPs are fully characterized. Transmission electron microscopy (TEM) analyses show the characteristics of spherical morphology with narrow size distribution, and a mean size from 4.2 to 17.5 nm depending on the ratio of the two starting materials of PEG−(COOH)2 to ferric triacetylacetonate (Fe(acac)3). Vibrating sample magnetometer analyses confirm the magnetic behavior of the PEG−(COOH)2 MNPs. The PEG−(COOH)2 layer on the MNPs ascertained from Fourier transform i...
TL;DR: A novel osmotic microbial fuel cell developed by using a forward osmosis (FO) membrane as a separator produced more electricity than the conventional MFC in both batch operation and continuous operation.
Abstract: Anovelosmoticmicrobialfuelcell(OsMFC)wasdevelopedbyusinga forwardosmosis(FO)membraneasaseparator.TheperformanceoftheOsMFCwas examined with either NaCl solution or artificial seawater as a catholyte (draw solution). A conventional MFC with a cation exchange membrane was also operated in parallel for comparison. It was found that the OsMFC produced more electricity than the MFC in both batch operation (NaCl solution) and continuous operation (seawater), likely due to better proton transport with water flux through the FO membrane. Water flux from the anode into the cathode was clearly observed with the OsMFC but not in the MFC. The solute concentration of the catholyte affected both electricity generation and water flux. These results provide a proof of concept that an OsMFC can simultaneously accomplish wastewater treatment, water extraction (from the wastewater), and electricity generation. The potential applications of the OsMFC are proposed for either water reuse (linking to reverse osmosis for reconcentration of draw solution) or seawater desalination (connecting with microbial desalination cells for further wastewater treatment and desalination).
TL;DR: In this paper, the effects of working temperature on separation performance (e.g., water fluxes and recoveries), membrane scaling and cleaning were systematically investigated through a bench-scale forward osmosis (FO) system.
TL;DR: The results suggest that the rejection of the micropollutants is increased by the presence of a fouling layer, possibly due to the higher hydrophilicity of the FO fouled membrane compared to the clean one, the increased adsorption capacity of hydrophilic compounds and reduced mass transport capacity, membrane swelling, and the higher negative charge of the membrane surface.
TL;DR: In this article, an integrated forward osmosis-membrane distillation (FO-MD) hybrid system has been demonstrated for the concentration of protein solutions, specifically a bovine serum albumin (BSA) solution.
TL;DR: In this article, a potentially sustainable integrated FO-UF (forward osmosis-ultrafiltration) system for water reuse and desalination with the aid of super hydrophilic nanoparticles as draw solutes has been proposed.
TL;DR: In this article, the relationship between physicochemical properties of the solution against the membrane support layer and ICP was explored by incorporating constrictivity, and four solutions with different diffusivities, ion/molecule sizes and viscosities were systematically investigated using a bench-scale forward osmosis system.
TL;DR: In this article, a salt accumulation model is developed in a novel osmotic membrane bioreactors (OMBRs) using a dense salt-rejecting forward osmosis membrane, which exhibits high retention of organic matter and various other contaminants.
TL;DR: The hybrid FO-RO process demonstrated that the dual barrier treatment of impaired water could lead to more than 99% rejection of almost all TOrCs that were identified in reclaimed water.
Abstract: Forward osmosis (FO) is a membrane separation technology that has been studied in recent years for application in water treatment and desalination. It can best be utilized as an advanced pretreatment for desalination processes such as reverse osmosis (RO) and nanofiltration (NF) to protect the membranes from scaling and fouling. In the current study the rejection of trace organic compounds (TOrCs) such as pharmaceuticals, personal care products, plasticizers, and flame-retardants by FO and a hybrid FO-RO system was investigated at both the bench- and pilot-scales. More than 30 compounds were analyzed, of which 23 nonionic and ionic TOrCs were identified and quantified in the studied wastewater effluent. Results revealed that almost all TOrCs were highly rejected by the FO membrane at the pilot scale while rejection at the bench scale was generally lower. Membrane fouling, especially under field conditions when wastewater effluent is the FO feed solution, plays a substantial role in increasing the rejectio...
TL;DR: In this article, the authors investigated the effects of membrane orientation on forward osmosis performance in saline water desalination without fouling, and with inorganic or organic fouling.
TL;DR: In this article, the authors proposed a hybrid FO/RO desalination system, which provides many advantages such as reducing RO fouling and scaling, recovery of osmotic energy of RO brine and minimizing the use of chemicals required for conventional pretreatment steps.
TL;DR: In this paper, a layer-by-layer (LbL) assembly of poly(allylamine hydrochloride) (PAH) and poly(sodium 4-styrene-sulfonate) (PSS) on a porous polyacrylonitrile (PAN) substrate was performed with glutaraldehyde (GA).
TL;DR: In this paper, an OMBR system was continuously operated for 73 days and it was found that the high retention property of the FO membrane and salt transmission from the draw solution resulted in increasing mixed liquor salinity until a stable state was reached.
TL;DR: In this paper, a computational fluid dynamics (CFD) model capable of simulating forward osmosis systems with asymmetric membranes is presented, which is inspired by previously published CFD models for pressure-driven systems and the general analytical theory for flux modeling in asymmetric membrane.
TL;DR: In this article, a composite polymer hydrogel with light-absorbing carbon particles incorporated within them that can be used as draw agents in the forward osmosis process of desalination is reported.
Abstract: We report here on new composite polymer hydrogel particles with light-absorbing carbon particles incorporated within them that can be used as draw agents in the forward osmosis process of desalination. These hydrogels are synthesized by free-radical polymerization of different monomers (e.g. sodium acrylate, N-isopropylacrylamide or their mixtures) and the crosslinker N,N′-methylenebisacrylamide with light-absorbing carbon particles. We have previously shown that hydrogel particles are able to draw pure water through forward osmosis membranes, and then the water can be removed by pressure or heating, or a mixture of both. The incorporation of light-absorbing particles leads to natural, enhanced heating and dewatering of the composites compared to neat hydrogels during such irradiation with light. However, it is also advantageously found that these composite polymer hydrogels exhibit higher swelling ratios, and thus produce higher water fluxes in the FO process. Furthermore, with the increasing loadings of carbon particles, the water recovery rates from the swollen composite hydrogels are found to be greatly enhanced.