Showing papers on "Reverse osmosis published in 2012"
TL;DR: A review of developing antifouling RO membranes in recent years, including the selection of new starting monomers, improvement of interfacial polymerization process, surface modification of conventional RO membrane by physical and chemical methods as well as the hybrid organic/inorganic RO membrane are presented.
777 citations
TL;DR: An overview on the potential treatments to overcome the environmental problems associated to the direct discharge of RO concentrates is given and recent studies that are mainly focused on reducing the organic pollutant load through the application of innovative advanced oxidation technologies are addressed.
647 citations
TL;DR: An energy consumption of 0.29 Wh l(-1) is demonstrated for the removal of 25% salt using this novel desalination battery, which is promising when compared to reverse osmosis, the most efficient technique presently available.
Abstract: Water desalination is an important approach to provide fresh water around the world, although its high energy consumption, and thus high cost, call for new, efficient technology. Here, we demonstrate the novel concept of a "desalination battery", which operates by performing cycles in reverse on our previously reported mixing entropy battery. Rather than generating electricity from salinity differences, as in mixing entropy batteries, desalination batteries use an electrical energy input to extract sodium and chloride ions from seawater and to generate fresh water. The desalination battery is comprised by a Na(2-x)Mn(5)O(10) nanorod positive electrode and Ag/AgCl negative electrode. Here, we demonstrate an energy consumption of 0.29 Wh l(-1) for the removal of 25% salt using this novel desalination battery, which is promising when compared to reverse osmosis (~ 0.2 Wh l(-1)), the most efficient technique presently available.
394 citations
TL;DR: In this article, a comprehensive review of the main innovations and future trends in the design of seawater reverse osmosis desalination technology is presented, with a special focus on the use of renewable energies as an innovation in the medium-term for medium and large production capacities.
385 citations
TL;DR: In this article, the authors proposed a flow-through electrode (FTE) capacitive desalination, where the feed water flows directly through electrodes along the primary electric field direction, which enables significant reduction in desalization time and can desalinate higher salinity feeds per charge.
Abstract: Capacitive desalination (CD) is a promising desalination technique as, relative to reverse osmosis (RO), it requires no membrane components, can operate at low (sub-osmotic) pressures, and can potentially utilize less energy for brackish water desalination. In a typical CD cell, the feed water flows through the separator layer between two electrically charged, nanoporous carbon electrodes. This architecture results in significant performance limitations, including an inability to easily (in a single charge) desalinate moderate brackish water feeds and slow, diffusion-limited desalination. We here describe an alternative architecture, where the feed flows directly through electrodes along the primary electric field direction, which we term flow-through electrode (FTE) capacitive desalination. Using macroscopic porous electrode theory, we show that FTE CD enables significant reductions in desalination time and can desalinate higher salinity feeds per charge. We then demonstrate these benefits using a custom-built FTE CD cell containing novel hierarchical carbon aerogel monoliths as an electrode material. The pore structure of our electrodes includes both micron-scale and sub-10 nm pores, allowing our electrodes to exhibit both low flow resistance and very high specific capacitance (>100 F g−1). Our cell demonstrates feed concentration reductions of up to 70 mM NaCl per charge and a mean sorption rate of nearly 1 mg NaCl per g aerogel per min, 4 to 10 times higher than that demonstrated by the typical CD cell architecture. We also show that, as predicted by our model, our cell desalinates the feed at the cell's RC timescale rather than the significantly longer diffusive timescale characteristic of typical CD cells.
350 citations
TL;DR: A thin film composite ABM was prepared by the interfacial polymerization method, where AquaporinZ-containing proteoliposomes were added to the m-phenylene-diamine aqueous solution and achieved significantly higher water permeability and comparable NaCl rejection than controls.
295 citations
TL;DR: The difference in the separation behaviour of these hydrophobic trace organics in the FO (using NaCl the draw solute) and RO modes could be explained by the phenomenon of retarded forward diffusion of solutes.
286 citations
TL;DR: In this article, an integrated forward and reverse osmosis process for seawater desalination for agricultural irrigation is proposed. But, the proposed method is limited in part because of high costs and energy consumption.
280 citations
TL;DR: In this paper, the authors highlight the recent developments of reverse osmosis (RO) TFC membrane and its challenges in seawater desalination process with respect to fouling problem, boron rejection and chlorine attack.
272 citations
TL;DR: The magnitude and distribution of adhesion forces suggest that the antifouling properties of the superhydrophilic membranes originate from the barrier provided by the tightly bound hydration layer at their surface, as well as from the neutralization of the native carboxyl groups of thin-film composite polyamide membranes.
Abstract: This study investigates the fouling behavior and fouling resistance of superhydrophilic thin-film composite forward osmosis membranes functionalized with surface-tailored nanoparticles. Fouling experiments in both forward osmosis and reverse osmosis modes are performed with three model organic foulants: alginate, bovine serum albumin, and Suwannee river natural organic matter. A solution comprising monovalent and divalent salts is employed to simulate the solution chemistry of typical wastewater effluents. Reduced fouling is consistently observed for the superhydrophilic membranes compared to control thin-film composite polyamide membranes, in both reverse and forward osmosis modes. The fouling resistance and cleaning efficiency of the functionalized membranes is particularly outstanding in forward osmosis mode where the driving force for water flux is an osmotic pressure difference. To understand the mechanism of fouling, the intermolecular interactions between the foulants and the membrane surface are a...
261 citations
TL;DR: A hybrid forward osmosis-nanofiltration (FO-NF) system designed for brackish water desalination was systematically investigated in this paper, and it was found that the hybrid FO-NF process has many advantages over the stand-alone RO process, such as lower hydraulic pressure, less flux decline caused by membrane fouling and higher flux recovery after cleaning.
TL;DR: The present study indicates that the use of NF membrane in dye removal from the effluent of Iraqi textile mills is promising and had higher removal potential with lower effective cost.
Abstract: Currently, biological method has been utilized in the treatment of wastewater -containing synthetic dyes used by textile industries in Iraq. The present work was devoted to study the operating feasibility using reverse osmosis (RO) and nanofiltration (NF) membrane systems as an alternative treatment method of wastewater discharged from Iraqi textile mills. Acid red, reactive black and reactive blue dyes were selected, based on the usage rate in Iraq. Effects of dye concentration, pH of solution, feed temperature, dissolved salts and operating pressure on permeate flux and dye rejection were studied. Results at operating conditions of dye concentration = 65 mg/L, feed temperature = 39°C and pressure = 8 bar showed the final dye removal with RO membrane as 97.2%, 99.58% and 99.9% for acid red, reactive black and reactive blue dyes, respectively. With NF membrane, the final dye removal were as 93.77%, 95.67%, and 97% for red, black and blue dyes, respectively. The presence of salt (particularly NaCl) in the dye solution resulted in a higher color removal with a permeate flux decline. It was confirmed that pH of solution had a positive impact on dye removal while feed temperature showed a different image. A comparison was made between the results of dye removal in biological and membrane methods. The results showed that membrane method had higher removal potential with lower effective cost. The present study indicates that the use of NF membrane in dye removal from the effluent of Iraqi textile mills is promising.
TL;DR: In this article, both 3D and 2D models were developed to mechanistically describe the relationship between support membrane pore structure, support material permeability, coating film thickness and resulting composite membrane permeability; in addition, an analytical model was developed as an approximate, but more convenient approach for assessing trends of composite membrane transport.
TL;DR: The present work confirmed the feasibility of electro-Fenton process for the treatment of RO concentrate accounting for its cost-effectiveness in wide pH ranges and investigated the in situ generation of hydrogen peroxide to gain insights into the process.
TL;DR: In this article, the authors examined the energy efficiency of single-stage MD-based desalination cycles in each of the MD configurations commonly used for desalification (direct contact, air gap, and vacuum) and compared the gained output ratio, or GOR, of each configuration across the range of membrane module geometries, and operating conditions.
TL;DR: A new experimental protocol is introduced that accounts for membrane deformation in a spacer-filled channel to determine the membrane properties (A, B, and S) and it is shown that at high pressures feed spacers block the permeation of water through the membrane area in contact with the spacer, thereby reducing overall water flux.
Abstract: This article analyzes the influence of feed channel spacers on the performance of pressure retarded osmosis (PRO). Unlike forward osmosis (FO), an important feature of PRO is the application of hydraulic pressure on the high salinity (draw solution) side to retard the permeating flow for energy conversion. We report the first observation of membrane deformation under the action of the high hydraulic pressure on the feed channel spacer and the resulting impact on membrane performance. Because of this observation, reverse osmosis and FO tests that are commonly used for measuring membrane transport properties (water and salt permeability coefficients, A and B, respectively) and the structural parameter (S) can no longer be considered appropriate for use in PRO analysis. To accurately predict the water flux as a function of applied hydraulic pressure difference and the resulting power density in PRO, we introduced a new experimental protocol that accounts for membrane deformation in a spacer-filled channel to...
TL;DR: In this article, a direct contact membrane distillation (DCMD)-based desalination process is explored in the range of 80-130°C for brines containing 10,000-ppm sodium chloride with porous flat sheet polytetrafluoroethylene (PTFE) membranes.
TL;DR: In this paper, a pressure-retarded osmosis (PRO) system between pure water and concentrated brine was used for salinity power generation using hollow fiber modules, which achieved the maximum output power density of 7.7 W/m2 at a 2.5 MPa hydraulic pressure difference and 38% permeation of pure water into the brine.
Abstract: Salinity power generation using hollow fiber modules was examined using the pressure-retarded osmosis (PRO) system between pure water and concentrated brine. Pure water and concentrated brine were supplied from a regional sewage treatment facility and sea water desalination (sea water reverse osmosis [SWRO]) plant. To minimize the effect of the concentration polarization near the membrane surface on the pure water side, the number of open ports in the module was increased from 3 to 4 and that modification was found to be effective because non-permeating pure water, which left the module through fourth port, flushed leaked salt from the brine side through the membrane. Our prototype PRO plant got the maximum output power density, 7.7 W/m2 at a 2.5 MPa hydraulic pressure difference and a 38% permeation of pure water into the brine. To remove the organic foulant in the pure water, a low pressure Reverse Osmosis (RO) membrane and coagulation–sedimentation method with ozonation showed good results. Ho...
TL;DR: System optimization analysis revealed that doubling FO membrane packing density, tripling FO membrane permeability, and optimizing system operation could reduce the environmental impact of the hybrid ODN-SWRO process compared to SWRO by more than 25%; yet, novel hybrid nanofiltration-RO treatment of seawater and wastewater can achieve almost similar levels of environmental impact.
TL;DR: In this paper, a double-skinned crosslinked layer-by-layer (xLbL) forward osmosis (FO) membrane with a double skin design has been synthesized and characterized.
TL;DR: The present review describes the recent advances made in radioactive waste treatment using membrane separation technology and discusses the membrane methods for collective separation of radionuclides.
TL;DR: In this paper, both S-1 and ZSM-5 membranes were tested using a pervaporation set up for the desalination of aqueous solutions containing NaCl in concentrations corresponding to brackish (0.3-1 wt), sea (3.5 wt%), and brine (7.5-15 wt%) water.
TL;DR: This review aims to provide a summary of research into bromide and iodide removal from drinking water sources and compared Halide removal techniques, and areas for future research have been identified.
TL;DR: In this paper, a commercial reverse osmosis (RO) membrane via layer-by-layer (LbL) assembly has been used to reduce membrane fouling of RO membrane and the obtained membranes exhibited antifouling properties against various hydrophobic foulants.
TL;DR: In this paper, the authors proposed the concept of fertiliser drawn forward osmosis (FDFO) desalination for non-potable irrigation where maximum water is required.
Abstract: With the world’s population growing rapidly, pressure is increasing on the limited fresh water resources Membrane technology could play a vital role in solving the water scarcity issues through alternative sources such as saline water sources and wastewater reclamation The current generation of membrane technologies, particularly reverse osmosis (RO), has significantly improved in performance However, RO desalination is still energy intensive and any effort to improve energy efficiency increases total cost of the product water Since energy, environment and climate change issues are all inter-related, desalination for large-scale irrigation requires new novel technologies that address the energy issues Forward osmosis (FO) is an emerging membrane technology However, FO desalination for potable water is still a challenge because, recovery and regeneration of draw solutes require additional processes and energy This article focuses on the application of FO desalination for non-potable irrigation where maximum water is required In this concept of fertiliser drawn FO (FDFO) desalination, fertilisers are used as draw solutions (DS) The diluted draw solution after desalination can be directly applied for fertigation without the need for recovery and regeneration of DS FDFO desalination can make irrigation water available at comparatively lower energy than the current desalination technologies As a low energy technology, FDFO can be easily powered by renewable energy sources and therefore suitable for inland and remote applications This article outlines the concept of FDFO desalination and critically evaluates the scope and limitations of this technology for fertigation, including suggestions on options to overcome some of these limitations
TL;DR: In this paper, the authors focused on characterization of the natural organic matter (NOM) fraction causing fouling on the active layer (AL) of a forward osmosis (FO) membrane in a novel plate and frame module configuration.
TL;DR: A review of the developments in the field of nitrate removal processes which can be effectively used for denitrifying ground water as well as industrial water can be found in this paper.
Abstract: Nitrate contamination of ground water resources has increased in Asia, Europe, United States, and various other parts of the world This trend has raised concern as nitrates cause methemoglobinemia and cancer Several treatment processes can remove nitrates from water with varying degrees of efficiency, cost, and ease of operation Available technical data, experience, and economics indicate that biological denitrification is more acceptable for nitrate removal than reverse osmosis and ion exchange This paper reviews the developments in the field of nitrate removal processes which can be effectively used for denitrifying ground water as well as industrial water
TL;DR: In this paper, a surface modified polyamide (PA) thin film composite (TFC) membrane was prepared using in-situ polymerization of sorbitol polyglycidyl ether (SPGE) on the membrane surface.
TL;DR: In this article, a large-scale integrated water reuse process based on MBR+RO technology (capacity 200 m3/d) has been designed and established in a German laundry within an EC funded project eventually resulting in a reuse ratio of around 80% of the total wastewater.
TL;DR: In this article, a pilot-scale membrane system was used for decolorization and removal of chemical oxygen demand and salts in dyewaters from dyewashing processes in a weaving industry.