Showing papers on "Desalination published in 2011"
TL;DR: The possible reductions in energy demand by state-of-the-art seawater Desalination technologies, the potential role of advanced materials and innovative technologies in improving performance, and the sustainability of desalination as a technological solution to global water shortages are reviewed.
Abstract: In recent years, numerous large-scale seawater desalination plants have been built in water-stressed countries to augment available water resources, and construction of new desalination plants is expected to increase in the near future. Despite major advancements in desalination technologies, seawater desalination is still more energy intensive compared to conventional technologies for the treatment of fresh water. There are also concerns about the potential environmental impacts of large-scale seawater desalination plants. Here, we review the possible reductions in energy demand by state-of-the-art seawater desalination technologies, the potential role of advanced materials and innovative technologies in improving performance, and the sustainability of desalination as a technological solution to global water shortages.
4,840 citations
TL;DR: A review of the development of reverse osmosis (RO) membrane materials can be found in this paper, where an overview of RO performance in relation to membrane materials and methods of synthesis is provided.
1,649 citations
TL;DR: In this paper, a tradeoff relation and upper bound between water permeability and water/salt selectivity are observed. But, the authors do not consider the effect of sample size and measurement variables (e.g., pressure and salt concentration in the case of salt rejection).
617 citations
TL;DR: This review focuses on nanostructured materials that are directly involved in the separation of water from salt as opposed to mitigating issues such as fouling and can potentially enable the development of next-generation desalination systems with increased efficiency and capacity.
Abstract: Desalination of seawater and brackish water is becoming an increasingly important means to address the scarcity of fresh water resources in the world. Decreasing the energy requirements and infrastructure costs of existing desalination technologies remains a challenge. By enabling the manipulation of matter and control of transport at nanometer length scales, the emergence of nanotechnology offers new opportunities to advance water desalination technologies. This review focuses on nanostructured materials that are directly involved in the separation of water from salt as opposed to mitigating issues such as fouling. We discuss separation mechanisms and novel transport phenomena in materials including zeolites, carbon nanotubes, and graphene with potential applications to reverse osmosis, capacitive deionization, and multi-stage flash, among others. Such nanostructured materials can potentially enable the development of next-generation desalination systems with increased efficiency and capacity.
593 citations
TL;DR: In this paper, the authors present a comprehensive review and assessment of desalination technologies such as thermal which includes multi-stage flash (MSF) and multiple effect distillation (MED), membrane reverse osmosis (RO), and hybrid (MS F/MED-RO).
562 citations
TL;DR: A review of recent advances in reverse osmosis technology as related to the major issues of concern in this rapidly growing desalination method is presented in this article, where a summary of the major advances in RO performance and mechanism modeling is also presented and available transport models are introduced.
560 citations
TL;DR: In this paper, the causes, consequences and control of biofouling in RO membranes used for seawater desalination are discussed in some detail: biofilm formation, role of EPS, and sequence of events leading to bio fouling.
543 citations
TL;DR: In this paper, the authors consider the mechanism of scale formation and the properties of alkaline, non-alkaline and silica based scales that are encountered when reverse osmosis is used in desalination, brackish water and wastewater recycling applications.
510 citations
TL;DR: In this paper, a country-level quantitative assessment of the water-energy nexus in the MENA region is performed, and the results show that up to 9% of the total annual electrical energy consumption may be attributed to ground water pumping and desalination.
449 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: A review on boron removal from seawater can be found in this article, where the main focus is on current and future technologies, current and the future for the removal of Boron.
TL;DR: In this paper, the authors have synthesized the graphene sheets by hydrogen induced exfoliation of graphitic oxide followed by functionalization, and these functionalized graphene sheets were used for simultaneous removal of high concentration of inorganic species of arsenic (both trivalent and pentavalent) and sodium from aqueous solution using supercapacitor based water filter.
TL;DR: In this paper, a gas hydrate-based desalination system was proposed with a dual cylinder unit, which is able to extract hydrate pellets from the reactor containing hydrate slurries.
TL;DR: In this article, a range of different charged and polar functional groups were added to a 1.1 nm diameter (8,8) CNT that was previously found to be only moderately effective at rejecting ions.
Abstract: The use of semipermeable membranes containing carbon nanotubes (CNTs) that form continuous pores has been suggested as a way to reduce the cost of desalination viareverse osmosis. Example membranes containing aligned CNTs have been fabricated, but obtaining only the very narrow pores that are able to block the passage of ions while allowing a rapid flow of water remains a challenge and previous computational studies have focused on idealised tubes. Here molecular dynamics simulations are used to examine water and ion transport through functionalised CNTs with the aim of investigating whether such chemical modification allows the performance of CNT based membranes to be improved, or for larger diameter pores to be used. A range of different charged and polar functional groups were added to a 1.1 nm diameter (8,8) CNT that was previously found to be only moderately effective at rejecting ions. These CNTs were incorporated into membranes and simulations were conducted with a hydrostatic pressure difference to determine the ion rejection and flux of water passing through each as well as the energy barriers presented to ions and water molecules. The results show that the addition of charges at the entrance of the pore can help to prevent the passage of ions, however, any functionalisation also reduces the flow of water through the membrane due to increased electrostatic interactions between the water molecules and the CNT. Assuming pore densities that have previously been achieved, the performance of these membranes in the simulations is still many times better than existing technology and thus the inclusion of functionalised CNTs in desalination membranes may prove to be useful in achieving salt rejection and rapid water flow.
TL;DR: A comprehensive review of all the indirect solar desalination technologies along with plant specific technical details is provided in this paper, where efforts assessing the economic feasibility and cost affecting parameters for each Desalination technology are also reviewed.
Abstract: Solar powered desalination has been the focus of great interest recently worldwide. In the past, majority of the experimental investigations focused on solar coupled thermally driven conventional desalination technologies such as Multi-Stage Flash (MSF) and Multi-Effect Distillation (MED). With the advancement in membrane technology and its advantages such as high Recovery Ratios (RR) and low specific energy requirements Reverse Osmosis (RO) desalination has gained popularity. Currently, 52% of the indirect solar desalination plants are RO based with MED and MSF having a 13% and 9% share respectively. Membrane Distillation (MD) based plants represent 16% of the total and have been a focus of recent research efforts. This paper aims to provide a comprehensive review of all the indirect solar desalination technologies along with plant specific technical details. Efforts assessing the economic feasibility and cost affecting parameters for each desalination technology are also reviewed.
TL;DR: A comprehensive review of energy minimization strategies for membrane-based desalination processes and utilization of lower GHG emission renewable energy resources is presented.
TL;DR: The correct application of Second Law efficiency shows which systems operate closest to the reversible limit and helps to indicate which systems have the greatest potential for improvement.
Abstract: Increasing global demand for fresh water is driving the development and implementation of a wide variety of seawater desalination technologies. Entropy generation analysis, and specifically, Second Law efficiency, is an important tool for illustrating the influence of irreversibilities within a system on the required energy input. When defining Second Law efficiency, the useful exergy output of the system must be properly defined. For desalination systems, this is the minimum least work of separation required to extract a unit of water from a feed stream of a given salinity. In order to evaluate the Second Law efficiency, entropy generation mechanisms present in a wide range of desalination processes are analyzed. In particular, entropy generated in the run down to equilibrium of discharge streams must be considered. Physical models are applied to estimate the magnitude of entropy generation by component and individual processes. These formulations are applied to calculate the total entropy generation in several desalination systems including multiple effect distillation, multistage flash, membrane distillation, mechanical vapor compression, reverse osmosis, and humidification-dehumidification. Within each technology, the relative importance of each source of entropy generation is discussed in order to determine which should be the target of entropy generation minimization. As given here, the correct application of Second Law efficiency shows which systems operate closest to the reversible limit and helps to indicate which systems have the greatest potential for improvement.
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: Carbon nanotube enhanced membrane distillation is presented for water desalination and it is demonstrated that the immobilization of the CNTs in the pores of a hydrophobic membrane favorably alters the water-membrane interactions to promote vapor permeability while preventing liquid penetration into the membrane pores.
Abstract: Carbon nanotube (CNT) enhanced membrane distillation is presented for water desalination. It is demonstrated that the immobilization of the CNTs in the pores of a hydrophobic membrane favorably alters the water−membrane interactions to promote vapor permeability while preventing liquid penetration into the membrane pores. For a salt concentration of 34 000 mg L−1 and at 80 °C, the nanotube incorporation led to 1.85 and 15 times increase in flux and salt reduction, respectively.
TL;DR: In this paper, the authors used electrodes made from single walled carbon nanotubes (SWCNTs) together with cation-and anion-exchange membranes for batch mode desalination.
TL;DR: The development of a continuously operated MDC--upflow microbial desalination cell (UMDC) for the purpose of salt removal demonstrated the potential of the UMDC as either a sole desalinated process or a pre-desalination reactor for downstream desalinating processes.
TL;DR: In this article, the authors focused on experimental studies on full-scale spiral wound MD-modules with a membrane surface area of 5-14m 2, and provided a comparison of a four module production charge.
TL;DR: Compared to slight changes in desalination, H(2) production was more significantly affected by the applied voltage and cathode buffer capacity, suggesting cathode reactions were likely affected byThe external power supply in addition to the anode microbial activity.
Abstract: The versatility of bioelectrochemical systems (BESs) makes them promising for various applications, and good combinations could make the system more applicable and economically effective. An integrated BES called microbial electrolysis and desalination cell (MEDC) was developed to concurrently desalinate salt water, produce hydrogen gas, and potentially treat wastewater. The reactor is divided into three chambers by inserting a pair of ion exchange membranes, with each chamber serving one of the three functions. With an added voltage of 0.8 V, lab scale batch study shows the MEDC achieved the highest H2 production rate of 1.5 m3/m3 d (1.6 mL/h) from the cathode chamber, while also removing 98.8% of the 10 g/L NaCl from the middle chamber. The anode recirculation alleviated pH and high salinity inhibition on bacterial activity and further increased system current density from 87.2 to 140 A/m3, leading to an improved desalination rate by 80% and H2 production by 30%. Compared to slight changes in desalinati...
TL;DR: In this article, the authors investigated the CDI characteristics of CNT sponges by simply compressing them into a CDI cell without any additives, and the deduced maximum desalination capacity was 40 mg g−1, almost 50% higher than the optimal result reported in the literature.
Abstract: Capacitive Deionization (CDI) is a promising method for desalination of brackish water because of its energy-efficiency as compared with conventional techniques such as membrane separation and thermal distillation. Carbon nanotube (CNT) sponges, prepared by chemical vapor deposition, are very flexible and have three-dimensional continuous and mesoporous structures, making them promising electrode materials for capacitive deionization. The CDI characteristics of CNT sponges were investigated for the first time by simply compressing them into a CDI cell without any additives. Desalination of NaCl solutions at different concentrations was conducted with a flow-through CDI cell at 1.2V. Experimental data fit well with the Langmuir model, and the deduced maximum desalination capacity was 40 mg g−1, almost 50% higher than the optimal result reported in the literature. By comparing with other carbon-based materials, the excellent CDI performance of CNT sponges was attributed to higher conductivity and larger effective surface area due to their monolithic continuous flexible framework, crystalline microstructure and preferred pore size distribution.
TL;DR: In this article, the authors investigated and reviewed alternative salt recovery methods that have been developed and widely employed were reviewed, and economic analysis of concentrate utilization in comparison with disposal was performed.
TL;DR: In this article, stacked microbial desalination cells (SMDCs) were developed in order to promote the desalization rate in a single-desalination-chambered MDC.
Abstract: Microbial desalination cell (MDC) is a new method to obtain clean water from brackish water using electricity generated from organic matters by exoelectrogenic bacteria. Anions and cations, derived from salt solution filled in the desalination chamber between the anode and cathode, move to the anode and cathode chambers under the force of electrical field, respectively. On the basis of the primitive single-desalination-chambered MDC, stacked microbial desalination cells (SMDCs) were developed in order to promote the desalination rate in the present study. The effects of desalination chamber number and external resistance were investigated. Results showed that a remarkable increase in the total desalination rate (TDR) could be obtained by means of increasing the desalination cell number and reducing the external resistance, which caused the charge transfer efficiency increased since the SMDCs enabled more pairs of ions separated while one electron passed through the external circuit. The maximum TDR of 0.0252 g/h was obtained using a two-desalination-chambered SMDC with an external resistance of 10 Ω, which was 1.4 times that of single-desalination-chambered MDC. SMDCs proved to be an effective approach to increase the total water desalination rate if provided a proper desalination chamber number and external resistance.
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.
01 Jan 2011
TL;DR: In this article, Membrane and desalination technologies, Membranes and desalinization technologies, membrane-and desalification technologies, and water desalinisation technologies are discussed.
Abstract: Membrane and desalination technologies , Membrane and desalination technologies , کتابخانه مرکزی دانشگاه علوم پزشکی تهران
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.