Different Types Of Membranes Research Articles

Fouling in Membrane Distillation, Osmotic Distillation and Osmotic Membrane Distillation

Various membrane separation processes are being used for seawater desalination and treatment of wastewaters in order to deal with the worldwide water shortage problem. Different types of membranes of distinct morphologies, structures and physico-chemical characteristics are employed. Among the considered membrane technologies, membrane distillation (MD), osmotic distillation (OD) and osmotic membrane distillation (OMD) use porous and hydrophobic membranes for production of distilled water and/or concentration of wastewaters for recovery and recycling of valuable compounds. However, the efficiency of these technologies is hampered by fouling phenomena. This refers to the accumulation of organic/inorganic deposits including biological matter on the membrane surface and/or in the membrane pores. Fouling in MD, OD and OMD differs from that observed in electric and pressure-driven membrane processes such electrodialysis (ED), membrane capacitive deionization (MCD), reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF), microfiltration (MF), etc. Other than pore blockage, fouling in MD, OD and OMD increases the risk of membrane pores wetting and reduces therefore the quantity and quality of the produced water or the concentration efficiency of the process. This review deals with the observed fouling phenomena in MD, OD and OMD. It highlights different detected fouling types (organic fouling, inorganic fouling and biofouling), fouling characterization techniques as well as various methods of fouling reduction including pretreatment, membrane modification, membrane cleaning and antiscalants application.

Effects of battery design, environmental temperature and electrolyte flowrate on thermal behaviour of a vanadium redox flow battery in different applications

This paper examines the effect of flowrate, cell number, tank dimension and environment temperature on the thermal behaviour of the vanadium redox flow battery. Simulations are carried out under a power arbitrage scenario for two different types of membranes. It was found that at high flowrates the thermal behaviour of the stack is similar to that of the storage tanks. Increasing the number of cells in the stack does not change the shape of the general thermal gradient across the cells, but changing the tank dimensions can affect the system temperature significantly. The environment temperature has a significant impact on the system thermal behaviour as does the types of membrane used. This study shows that by altering the parameters, the thermal behaviour of the system can be regulated and even, in some cases, controlled within desirable ranges to prevent vanadium salt precipitation at temperature extremes.

Performances of nanofiltration and low pressure reverse osmosis membranes for desalination: characterization and modelling

The nanofiltration and the reverse osmosis processes are the most common techniques for the desalination of water contaminated by an excess of salts. In this present study, we were interested in the characterization of commercial, composite and asymmetric membranes of nanofiltration (NF90, NF270) and low pressure reverse osmosis (BW30LE). The two types of characterization that we opted for our study: (i) characterization of electrical proprieties, in terms of the surface charge of various membranes studied by the measurement of the streaming potential, (ii) hydrodynamic characterization in terms of hydraulic permeability with pure water, mass transfer and phenomenological parameters for each system membrane/salt using hydrodynamic approaches. The irreversible thermodynamics allowed us to model the observed retention Robs of salts (NaCl and Na2SO4) for the different membranes studied, to understand and to predict a good filtration with a membrane. A study was conducted on the type of mass transfer for each system membrane/salt: convection and diffusion. The results showed that all tested membranes are negatively charged for the solutions at neutral pH, this is explained by their material composition. The results also showed competitiveness between the different types of membranes. In view of that the NF remains effective in terms of selective retention with less energy consumption than LPRO.

PREPARATION AND CHARACTERIZATION OF SUPERHYDROPHILIC NANOCOMPOSITE ULTRAFILTRATION MEMBRANES FOR TREATMENT OF HIGHLY CONCENTRATED OIL-IN-WATER EMULSION

In oily wastewater treatment using membrane technology, surface fouling is the major issue that could deteriorate membrane flux and shorten its lifespan. Therefore, nanocomposite membranes were developed in this study by incorporating titanium dioxide (TiO2) and hydrous manganese oxide (HMO) nanoparticles into polymeric membrane matrix. Three different types of membranes were fabricated. They were pristine PES and membrane incorporated with TiO2 or HMO. With respect to pure water flux, TiO2- and HMO-incorporated membranes showed value of 57 and 40 L/m2.h, respectively. These values were 33-90% higher than that of control PES membrane. In treating 500 ppm oily solution, TiO2 membrane exhibited the highest water flux. However, the membrane’s oil removal rate was slightly compromised. When tested with higher concentration of oily solution (5,000 or 10,000 ppm), TiO2- and HMO-incorporated membranes still showed promising water flux with 94.5-99.6% oil removal rate. This proved that ultrafiltration membrane incorporated with suitable nanomaterials could improve the water flux of pristine PES membrane and is of more practical for industrial applications.

Limitations and options using resorbable versus nonresorbable membranes for successful guided bone regeneration.

Deficient bony ridges often complicate the implant treatment plan. Several treatment modalities are used to regenerate bone, including guided bone regeneration (GBR). The purpose of this study was to summarize the knowledge on different types of membranes available and currently used in GBR procedures in a staged approach or with simultaneous implant placement. The primary role of the membranes is to exclude epithelial and connective tissue cells from the wound area to be regenerated, and to create and maintain the space into which pluripotential and osteogenic cells are free to migrate. A literature search was performed for articles that were published in English on the topic. A selected number of studies were chosen in order to provide a review of the main characteristics, applications, and outcomes of the different types of membranes. Resorbable membranes are made of natural or synthetic polymers like collagen and aliphatic polyesters. Collagens are the most common type used. They have similar collagen composition to the periodontal connective tissue. Other materials available include human, porcine, and bovine pericardium membranes, human amnion and chorion tissue, and human acellular freeze-dried dermal matrix. Nonresorbable membranes used in GBR include dense-polytetrafluoroethylene (d-PTFE), expanded-polytetrafluoroethylene (e-PTFE), titanium mesh, and titanium-reinforced polytetrafluoroethylene. The most common complication of nonresorbable membranes is exposure, which has detrimental effect on the final outcome with both types of membranes. For vertical bone augmentation procedures, the most appropriate membranes are the nonresorbable. For combination defects, both types result in a successful outcome.

The Critical Role of Supporting Electrolyte Selection on Flow Battery Cost

Redox flow batteries (RFBs) are promising devices for grid energy storage, but additional cost reductions are needed to meet the U.S. Department of Energy recommended capital cost of $150 kWh−1 for an installed system. The development of new active species designed to lower cost or improve performance is a promising approach, but these new materials often require compatible electrolytes that optimize stability, solubility, and reaction kinetics. This work quantifies changes in RFB cost performance for different aqueous supporting electrolytes paired with different types of membranes. A techno-economic model is also used to estimate RFB-system costs for the different membrane and supporting salt options considered herein. Beyond the conventional RFB design incorporating small active species and an ion-exchange membrane (IEM), this work also considers size-selective separators as a cost-effective alternative to IEMs. The size selective separator (SSS) concept utilizes nanoporous separators with no functionalization for ion selectivity, and the active species are large enough that they cannot pass through the separator pores. Our analysis finds that SSS or H+-IEM are most promising to achieve cost targets for aqueous RFBs, and supporting electrolyte selection yields cost differences in the $100’s kWh−1.

Novel silk protein barrier membranes for guided bone regeneration.

This study assesses the biocompatibility of novel silk protein membranes with and without modification, and evaluates their effect on facilitating bone formation and defect repair in guided bone regeneration. Two calvarian bone defects 12 mm in diameter were created in each of a total of 38 rabbits. Four different types of membranes, (silk-, hydroxyapatite-modified silk-, β-TCP-modified silk- and commonly clinically used collagen-membranes) were implanted to cover one of the two defects in each animal. Histologic analysis did not show any adverse tissue reactions in any of the defect sites indicating good biocompatibility of all silk protein membranes. Histomorphometric and histologic evaluation revealed that collagen and β-TCP modified silk membranes supported bone formation (collagen: bone area fraction p = 0.025; significant; β-TCP modified silk membranes bone area fraction: p = 0.24, not significant), guided bone regeneration and defect bridging. The bone, which had formed in defects covered by β-TCP modified silk membranes, displayed a more advanced stage of bone tissue maturation with restoration of the original calvarial bone microarchitecture when compared to the bone which had formed in defects, for which any of the other test membranes were used. Micro-CT analysis did not reveal any differences in the amount of bone formation between defects with and without membranes. In contrast to the collagen membranes, β-TCP modified silk membranes were visible in all cases and may therefore be advantageous for further supporting bone formation beyond 10 weeks and preventing soft tissue ingrowth from the periphery. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2603-2611, 2017.

Characterization and Performance Evaluation of Ultrafiltration Membrane for Humic Acid Removal

Background/Objectives: Humic Acid (HA) appears in conventional water treatment processes will compose to carcinogenic disinfection by-products. This has sparked this study to examine the effectiveness of polymeric membranes in HA removal. Methods/Statistical Analysis: Different types of membranes with a wide range of Molecular Weight Cut-Off (MWCO) were used in this study and their separation performances were evaluated by varying the Transmembrane Pressure (TMP) and HA concentrations. The permeates and feeds were analyzed by measuring the UV absorbance at wavelength of 254 nm. Findings: Among four membrane modules that used in this study, it was found that membrane Modules 1, 2 and 3 demonstrated similar performances in HA removal with a separation rate of at least 50%. Excellent HA separation (>90%) was reported with the use of membrane Module 4. Increasing of HA concentration from 0.1 to 0.2 mg/L did not expressively reduce membrane efficiency. These membranes however having severe fouling which contributed to a low permeate flow rates after a few runs. The permeate flux was initially high but reduced over the operation time. Simple cleaning could be conducted to recover the permeate flux but not 100% recovery as compared to the original fresh membranes. Application/Improvements: Based on the experiments, it can be established that the hollow fiber UF membrane is suitable for HA removal.

Chemical properties of lipids strongly affect the kinetics of the membrane-induced aggregation of α-synuclein.

Intracellular α-synuclein deposits, known as Lewy bodies, have been linked to a range of neurodegenerative disorders, including Parkinson's disease. α-Synuclein binds to synthetic and biological lipids, and this interaction has been shown to play a crucial role for both α-synuclein's native function, including synaptic plasticity, and the initiation of its aggregation. Here, we describe the interplay between the lipid properties and the lipid binding and aggregation propensity of α-synuclein. In particular, we have observed that the binding of α-synuclein to model membranes is much stronger when the latter is in the fluid rather than the gel phase, and that this binding induces a segregation of the lipids into protein-poor and protein-rich populations. In addition, α-synuclein was found to aggregate at detectable rates only when interacting with membranes composed of the most soluble lipids investigated here. Overall, our results show that the chemical properties of lipids determine whether or not the lipids can trigger the aggregation of α-synuclein, thus affecting the balance between functional and aberrant behavior of the protein.

Life cycle assessment of membrane-based carbon capture and storage

Many investigations have conducted life cycle assessments (LCA) of the most commonly discussed routes of carbon capture and storage (CCS): post-combustion with amine wash separation; oxyfuel using cryogenic air separation and pre-combustion by integrated gasification combined cycle (IGCC) using physical separation. A research alliance developed corresponding separation systems using different types of membranes to allow a more energy efficient separation process: polyactive polymeric membranes for post-combustion, ceramic membranes for oxyfuel and metallic membranes for IGCC separation. By conducting an LCA, the study examines the actual greenhouse gas emissions and other environmental impacts of the new membrane separation technologies, together with concepts implementing the more common technologies. The reference systems represent today’s state-of-the-art supercritical coal fired power plant in Germany, together with a more advanced ultra-supercritical plant operating at 700 °C without CO2 capture. The results demonstrate that among the three reference power plants the IGCC is the superior concept due to the highest efficiency. Regarding climate change, the IGCC power plants with CO2 capture are still the best concepts. When other environmental impacts are considered, the capture technologies are inferior. The membrane concepts show the overall better results in comparison to the conventional capture technologies. The environmental impacts for membrane applications add a new range of findings to the field of CCS LCAs. Now the results for several different approaches can be compared directly for the first time.

Protein adsorption through Chitosan-Alginate membranes for potential applications.

BackgroundChitosan and Alginate were used as biopolymers to prepare membranes for protein adsorption. The network requires a cross-linker able to form bridges between polymeric chains. Viscopearl-mini® (VM) was used as a support to synthesize them. Six different types of membranes were prepared using the main compounds of the matrix: VM, Chitosan of low and medium molecular weight, and Alginate.ResultsExperiments were carried out to analyze the interactions within the matrix and improvements were found against porous cellulose beads. SEM characterization showed dispersion in the compounds. According to TGA, thermal behaviour remains similar for all compounds. Mechanical tests demonstrate the modulus of the composites increases for all samples, with major impact on materials containing VM. The adsorption capacity results showed that with the removal of globular protein, as the adsorbed amount increased, the adsorption percentage of Myoglobin from Horse Heart (MHH) decreased. Molecular electrostatic potential studies of Chitosan–Alginate have been performed by density functional theory (DFT) and ONIOM calculations (Our own N-layered integrated molecular orbital and molecular mechanics) which model large molecules by defining two or three layers within the structure that are treated at different levels of accuracy, at B3LYP/6-31G(d) and PM6/6-31G(d) level of theory, using PCM (polarizable continuum model) solvation model.ConclusionsFinally, Viscopearl-mini® acts as a suitable support on the matrix for the synthesis of Chitosan–Alginate membranes instead of cross-linkers usage. Therefore, it suggests that it is a promise material for potential applications, such as: biomedical, wastewater treatment, among others.Graphical abstractChitosan, Alginate, and Cellulose beads-based membranes for protein adsorption. Special attention was given for preparation, charaterization, adsorption capacity, and molecular electrostatic potential studies calculation. Viscopearl-mini® gives support on the matrix of Chitosan–Alginate membranes instead of cross-linkers usage

Nanocomposite Membrane with Different Carbon Nanotubes Location for Nanofiltration and Forward Osmosis Applications

We investigated the effect of carbon nanotubes (CNTs) location on the property and performance of prepared membranes. Four different types of membranes were prepared, including (1) thin film composite (TFC, polyamide active layer on polysulfone substrate), (2) nanocomposite-supported thin film composite (nTFC, polyamide active layer on CNT-embedded polysulfone substrate), (3) thin film nanocomposite (TFN, CNT-incorporated polyamide active layer on polysulfone substrate), and (4) nanocomposite-supported thin film nanocomposite (nTFN, CNT-incorporated polyamide active layer on CNT-embedded polysulfone substrate). The water permeability followed the sequence of nTFN > TFN > nTFC > TFC. However, the rejection and salt permeability exhibited the opposite trend. The incompatibility between CNTs and polymers provided nanocorridors, through which both water and solutes could pass. The nTFN membrane exhibited the highest porosity and lowest structural parameter. Moreover, the nTFN membrane possessed the best antif...

Role of Facilitated Transport Membranes and Composite Membranes for Efficient CO2 Capture – A Review

AbstractCO2 emission from anthropogenic sources has raised global environmental concerns, and efficient reduction of these greenhouse gas emissions by capturing CO2 is recognized world‐wide as very important along with the implementation of new green energy technology. Membrane technology is considered to be one of the efficient techniques to be used for CO2 capture. Among different types of membranes, mixed matrix membranes and facilitated transport membranes have gained much interest in recent years due to documented high CO2 permeance through these membranes, especially when the gas is humid as is the case for flue gas from combustion. In the current review, a comprehensive discussion is focused on the development of hybrid membranes involving the selection of the fixed site carrier (FSC) membranes and the interaction of nanosilica‐particles in a polymer membrane for efficient CO2 capture. Other facilitated transport membranes and mixed matrix membranes are also briefly discussed.

Assessing the feasibility of two hybrid MBR systems using PAC for removing macro and micropollutants

The removal of 10 organic micropollutants (OMPs) was studied in two MBRs using different types of membrane (flat sheet microfiltration, MF, and hollow fiber ultrafiltration, UF) operated under aerobic conditions with direct dosing of powdered activated carbon (PAC) in the mixed liquor. In both reactors high COD degradation and nitrification were achieved (>95%), while nitrate removal was only observed after PAC addition. The adsorbent improved the operation of both systems (sludge properties and microbial diversity) which resulted in an enhancement of the quality of the final effluent. The operation with both types of membrane was feasible being the UF system slightly better in terms of the quality of the final effluent. The strategy of 250 mg/L of PAC additions every 35 days was validated according to the results obtained for the removal of the most recalcitrant OMPs, such as diclofenac and carbamazepine. Concerning the type of membrane, only significant differences were observed for diclofenac and roxithromycin, which were better removed in the UF configuration. These differences were attributed to sorption and/or further biotransformation processes occurring in the cake layer.

Deacidification of cranberry juice by electrodialysis: Impact of membrane types and configurations on acid migration and juice physicochemical characteristics

Abstract Cranberry is a typical fruit from North America having a very high acidity that makes raw juice hardly acceptable for consumers. In this study, the reduction of juice acidity was investigated using electrodialysis (ED) with different types of membranes and cell configurations. Electrodialysis is an ecofriendly membrane technology used in a large range of food applications. Three different ED configurations were tested at the laboratory scale: bipolar and anion-exchange membranes (ED2MB), bipolar and ultrafiltration membranes (ED2MBUF), and cation-exchange and ultrafiltration membranes (EDUF). Each configuration was evaluated in terms of juice physicochemical parameters (titratable acidity, conductivity, total soluble solids, color, anthocyanins, organic acids and mineral contents) and electrodialytic parameters (membrane conductivity and thicknesses, global system resistance). In ED2MB configuration, a 40% deacidification rate was reached after 3 h of treatment (80% after 6 h) whereas 0% and only 8% were obtained after 3 h with ED2MBUF and EDUF configurations, respectively. Furthermore, a selective migration of organic acids was observed with the ED2MB configuration: citric acid (22 ppm/min), malic acid (11 ppm/min) and quinic acid (6.5 ppm/min). Consequently, ED2MB configuration allows the deacidification of cranberry juice and the production of pure acids (no waste generated) without any chemical consumption due to the bipolar membrane in-situ generation of proton and hydroxyl species from water.

CO2 Separation from Flue Gases Using Different Types of Membranes

The emission of greenhouse gases such as CO2 is the main cause of global warming. Its separation from different emission sources such as chemical industries, power stations etc. to reduce greenhouse effect has been a mutual interest of the world. Conventional processes such as absorption, cryogenic distillation and adsorption used for this purpose but there are some drawbacks such as high energy consumption, process complexity and high capital cost are major issues which need some efficient alternative technique to be worked on. The developing technique such as Membrane separation is highly compact, energy efficient, environmental friendly, scale-up flexible and possibly more economical than previously well-established technologies. The purpose of this review is to classify membrane separation process used for CO2 gas separation from flue gases. This review covers introduction of membrane includingpolymeric and inorganic membranes, provide recent advancements such as mixed matrix membranes, facilitated transport membranes and carbon membranes which have improved permeability and selectivity. This review also portraits the basic differences between different types of membranes used for CO2 separation, highlighted operating conditions for different membranes and mention further research possibilities in this field.

Response of different osmotic membranes and calibration of a coupled model capturing the temperature effect for the osmotic method

Reliable suction control is of paramount importance for experimental unsaturated soil mechanics. The osmotic method, based on polyethylene glycol (PEG) and semi-permeable membranes, is one of the possible methods to control suction. Although this method is quite simple to implement, reliable results can only be obtained with adequate calibration curves linking suction and PEG concentration, and a good understanding of the factors influencing the method. Several studies have investigated different aspects of this method, including the osmotic potential generated by given PEG concentrations, but the effect of temperature is not yet fully captured. This paper presents the results of a comprehensive study of the osmotic method looking at the long-term response of three different types of membranes, the effect of temperature, PEG molecular weight (MW) and the combination of different MW cut off (MWCO) on the calibration curves. Finally the data were used to calibrate a model capturing the temperature effect, in a coupled manner, in order to provide a robust calibration.

Biological Waste Gas Treatment using Membrane Based Technology

This article presents a literature review on developments of membrane reactors for biological waste gas treatment as well as examples of applications to different compounds. The use of membranes combines selective separation of compounds from a waste gas stream followed by biological removal. Gas transport phenomena and different types of membranes used in biological waste gas treatment are discussed. So far, membrane-based biological waste gas treatment has only been tested on laboratory scale. If the long-term stability of these reactors can be demonstrated, membrane bioreactor technology can be useful in the treatment of gas streams containing poorly water-soluble pollutants and highly chlorinated hydrocarbons, which are difficult to treat with conventional methods for biological waste gas treatment.

Solubilization and Characterization of β-Mannosyltransferase from Pig Aorta

Glycosyltransferase in general play a very important role in the post-translational modification of number of biomolecules including glycoproteins. The glycosylation of the protein occurs in the endoplasmic reticulum and is carried out by at least 14 different types of membrane bound glycosyltransferases. It is now well established that glycosylation of protein occurs either at serine or threonine residues (O-glycosylation) or at asparagine residue (N-glycosylation) of proteins. To date there is no definite demonstration of the presence of O-mannosylation of proteins in higher eukaryotes. However, it is a common feature in yeast and other fungal strain, indicating that glycosyltransferases are species-specific as well as tissue-specific. In higher eukaryotes the Nglycosylation is the major post translational process, initiated by the synthesis of a large lipid oligosaccharide, Glc3-Man9-GlcNAc2-PP-Dolichol. This represents the immediate precursor of carbohydrate unit involved in the biosynthesis of glycoproteins. The large oligosaccharide is then transferred from the lipid oligosaccharide to the acceptor lipid by the oligosaccharide transferase. β-Mannosyltransferase is the key enzyme of the dolichol pathway that catalyzes the transfer of mannose to the chitobiose lipid (GlcNAc2-PP-Dol), acceptor substrate from GDP-mannose. This enzyme has been purified to near homogeneity and characterized from pig aorta tissue, using different chromatography techniques, and studying its properties.

Fundamental study of a novel membrane filtration cleanup method for pesticide analysis in agricultural products

The recovery and purification characteristics of membrane filtration for pesticide analysis of agricultural products were investigated. Eight different types of membranes classified by their molecular weight cut off (MWCO) and material were used. The results showed that the recovery and purification characteristics varied according to the eluting solvent used, as well as the membrane's MWCO and material. The recovery increased as the MWCO increased, and the purification increased when the eluting solvent contained water. A GK membrane with acetonitrile-water (1:1, v/v) was the most effective membrane filtration method among those tested. The pesticide analysis of spinach using the GK filtration method indicated that this method results in better purification than the modified QuEChERS method.