Scientific World Index Directory

Search For Articles :

Entries for Scientific Index

Displaying 281 - 320 of 459 1 2 3 4 5 6 7 8 9 10 11 12
Title Author 1 Author 2 Abstract PDF
Ibuprofen Recovery from Aqueous Solutions by Supported Liquid Membranes Teresa A. Razo-Lazcano

Abstract: Pharmaceuticals recently have acquired a big importance because of its growing detection in wastewater. The
propionic acid derivatives, such as ibuprofen, are among the most commonly anti-inflammatories used by population. For
this reason it is necessary to develop a friendly separation technique with environment, like the Supported Liquid
Membranes (SLM). In this work, SLM have been prepared in order to recover ibuprofen from aqueous solutions. Two
different organic phases were evaluated (dodecane and Parleam 4), as well as trioctylamine as carrier, and Abil EM 90
as surfactant in the preparation of SLM. The SLM prepared was tested in the IBP transfer process through the
membrane, from feed phase to stripping phase. The results showed that it is possible to recover almost 98% of IBP, this
using the SLM and a phosphate buffer solution of pH 7 like stripping phase.

Effect of Inclusion of 1-Butyl-3-Methylimidazolium Trifluoromethanesulfonate on CO2 and N2Permeabilities for PVDF and PVDF-HFP Membranes Takashi Makino1,* Mitsuhiro Kanakubo

Abstract: The CO2 and N2 permeabilities for polymer inclusion membranes, consisting of 1-butyl-3-methylimidazolium
trifluoromethanesulfonate ([bmim][TfO]) in poly (vinylidenedifluoride) (PVDF) and poly (vinilidenedifluoride-cohexafluoropropylene)
(PVDF-HFP), at the temperatures from 298.2 K to 348.2 K, have been evaluated. The PVDF and
PVDF-HFP membranes, containing 75 wt% of [bmim][TfO], had the CO2 permeabilities of 585 and 976 barrers,
respectively, and the CO2 selectivities of 15 at 348.2 K. These values were higher than those of the supported ionic liquid
membrane of [bmim][TfO] (428 barrers and 12). Furthermore, the Differential scanning calorimetry and Raman
spectroscopy were performed to analyze the micro-structures of membranes. These analyses indicate that the polymer
matrix was plasticized and the polymorphs changed from the non-polar α-phase to the polar β-phase by the addition of
[bmim][TfO]. According to the solution-diffusion transport mechanism, it is concluded that the inclusion membranes with
the sufficiently plasticized, i.e. phase-changed, PVDF and PVDF-HFP membranes absorbed the larger amount of gas
species than the neat [bmim][TfO], and PVDF-HFP is more effective than PVDF for the enhancement in gas absorption.

A Vegetable Oil-based Green Process for the Membrane Extraction of Ionic Solutes M. Hossain*  

Abstract: Extraction or removal of the polluting components can be accomplished by a variety of physical, chemical and
biological methods. Solvent extraction has demonstrated as one of the promising methods to accomplish the extraction
or removal of ions more or less selectively from the source streams. The processes, especially when operated in
membrane modules, have been successful and effective in reducing the pollutant concentration. In the development of
these processes in to industrial operations the solvents (or the extracting phase) used or recommended in the literature
are from non-sustainable source, they have undesirable properties (toxic, corrosive and health and safety issues). In
recent years there have been research work to examine the feasibility of other solvents from sustainable sources and
with good characteristics to overcome or minimize some of the above adverse effects. In this paper, the effectiveness of
sunflower oil (as a model for vegetable oil), is described in extraction (or removal) of a polluting component in a smallscale
membrane contactor. The components are: chromate ion and ammonium ion and the process is developed using a
carrier molecule (di-2-ethylhexyl phosphate for ammonium and Aliquat 336 for chromate) in sunflower oil. The removal
percentages are very good (in the range of 43-99%) and obtained at their natural conditions (with no chemical added for
the adjustment of pH) of the aqueous feed. The main attraction of the process is the good performance of sunflower oil,
which can be considered a “green” solvent system as it has the benefit of being environmentally friendly, less costly,
non-toxic and sustainable.

Organic Micropollutant Removal by a Nanofiltration Pilot Plant used to Treat Spring Water from a Wastewater-Irrigated Valley Alma Chávez* Francisco J. Torner

Abstract: The abundance of freshwater springs in the Tula Valley is well documented. Large quantities of untreated
wastewater from Mexico City are used for irrigation purposes, with the resultant emerging springs. Studies are needed to
assess how safe water is to be supplied to the community. Comparative membrane studies were done on lab-scale, from
which NF270 membrane was selected for a pilot plant in situ (critical flux 185Lm-2h-1). The system was successful at
removing natural organic matter, hardness and pathogenic content. On-site membrane pretreatment using microfiltration and
softening allowed moderate recoveries (60%) and slow permeate flux losses (124-90Lm-2h-1). Micropollutant (MP) removal was
greater than 90% for most of the pharmaceuticals, hormones and phthalates using spiked spring water. However,
moderate and variable removals were found when the concentrations of MPs were very low. Molecular structure and
hydrophobicity were loosely related to the removal rates of the compounds evaluated, however an accumulating effect
on the membrane might be key for higher MP removals. A threshold of concentration could have to be overcome to allow the
removal process to achieve a better performance. In consequence, optimization of a large-scale process is the next step to

Hydrogen Production using Solar Membrane Reactor Technology Ali Khosravani Elahe Safaee*

Abstract: Fossil fuels as energy resources are decreasing rapidly which will cause a fuel supply crisis in the future.
Based on the predictions, global energy consumption has been increased significantly and will continue to rise about two
times higher than now till 2050. On the other hand, the extent of the pollutions released from each of the fossil fuels
made too many problems for human’s lives. Thus, the need for new energy sources has increased recently. The need of
affordable and clean alternatives for fossil fuels convinced researchers to test other technologies for energy creation. For
example, electrical energy produced by fuel cells is one of the perfect solutions to decrease environmental pollution due
to its high efficiency, non-environmental pollution and consumption of hydrogen as a clean fuel. Generally hydrogen can
be obtained from various sources such as fossil fuels (natural gas reforming of coal and natural gas), renewable
resources, water electrolysis and etc. Of course, each of these processes has its advantages and disadvantages in
different conditions. The solar reactor membrane technology in recent years has been proposed as an effective way to
produce hydrogen from renewable sources. The purpose of this study is on hydrogen production processes using solar
membrane reactor technology. Therefore, various hydrogen production methods have been proposed and the
advantages and disadvantages of each method have been analyzed. The combination of membrane technology with
solar technology and the developments in solar membrane systems is a good alternative to fossil fuels as a green
process for hydrogen production, which is cost-effective in terms of thermal efficiency and fuel consumption rate.

Removal of Diclofenac from Water using an Hybrid Process Combining Activated Carbon Adsorption and Ultrafiltration or Microfiltration Hassan Abdi Bogoreh Catherine Charcosset*

Abstract: Small amounts of pharmaceuticals are increasingly found in natural waters and wastewaters in treatment
plants. Several processes are developed for their removal such as hybrid membrane processes. These techniques
integrate membrane filtration (mainly ultrafiltration or microfiltration) to a physical technique (such as flocculation or
sorption on activated carbon). In this study, we report results on a process with sorption on activated carbon and
microfiltration or ultrafiltration using a ceramic membrane, with a specific attention to the influence of the membrane pore
size. The membranes showed little fouling at the experimental conditions used (maximum 500 mg/L activated carbon),
while an important increase in conductivity was observed in permeate samples due to the salting out of ions from the
activated carbon particles. Besides, the removal of diclofenac and humic acid (both at 10 mg/L) was higher than 90 %
during the treatment with both ultrafiltration and microfiltration, however microfiltration was preferred due to its higher
flux. These results suggest that hybrid processes of activated carbon/ultrafiltration or microfiltration could be interesting
alternatives for processing waters containing small amounts of pharmaceuticals.

Comparative Study on Composite Electrodes for Medium Temperature PEFC I. Gatto A. Carbone*

Abstract: The purpose of the present study consists in the development of a MEA (Membrane-Electrode-Assembly) for
Polymer Electrolyte Fuel Cells (PEFCs) applications at intermediate temperatures (T>100°C) through the introduction of
inorganic compounds within the catalytic layer of the electrodes. For this aim, composite electrodes containing three
inorganic compounds, with different chemical and physical properties, were developed with percentages ranging
between 0-14 wt% of zeolite H-BETA, titania (TiO2) and yttria stabilized zirconia (YSZ) maintaining the same Platinum
loading of 0.5 mg/cm2 and assembling the electrodes to a commercial N115 membrane. Electrochemical studies in terms
of V-I curves were carried out in a temperature range of 80-130°C in order to select the optimal content of filler.
A comparison between the standard electrode and the best composite electrode containing the optimal amount for each
investigated inorganic material was carried out. The role of inorganic materials is to limit the ionomer swelling by
maintaining the mechanical characteristics of the polymer quite unaltered and to enhance the durability of the
electrocatalyst to degradation phenomena during the fuel cell operation at a temperature over the critical one. For each
inorganic material, a different optimal amount was found to be dependent on their chemical-physical properties, in
particular the particle size, acidity and intrinsic proton conductivity. At high temperature (130°C), the beneficial effect of
oxides introduction is more evident: a reduced cell resistance, a reduced Tafel slope, increased OCV values and
improved fuel cell performance for composite electrodes than the standard one. It was supposed that a limit in the oxide
introduction exists and it depends on physical properties of the inorganic filler, in particular the grain size, the acidity, the
intrinsic proton conductivity and the physical properties of the polymeric matrix used as an ionomer.

Diffusion of C1-C3 Alkanes in Semicrystalline Poly(4-Methyl-1- Pentene) as a Two-Phase Polymeric System S.Y. Markova I.N. Beckman

Abstract: Poly(4-methyl-1-pentene) (PMP) is using up to now as the hollow fiber air separation membranes. This
polymer with good resistance to organics attack can be prospective for separation of lower hydrocarbons.
An attempt for the theoretical consideration and experimental study of the C1-C3 alkanes diffusion in poly(4-methyl-1-
pentene) (PMP) as a binary system in the temperature range from 253,K to 353, K covering the glass transition region of
PMP (~ 303, K) is carried out in this work. The permeability of CH4, C2H6, C3H8 has been measured by the permeability
differential method under the partial pressure drop across the membrane 1 bar with the gas chromatography analysis of
the permeate flux. The diffusion coefficients have been calculated from the experimental differential permeability curves
by using linearization method developed earlier. Novelty of results is that at temperatures below Tg PMP can be
considered as a single-phase system from the gas transfer point of view. At the temperatures above Tg PMP can be
considered as a two-phase medium with diffusion coefficients of C1-C3 alkanes in amorphous (Da) and crystalline phases
(Dc) (Da>Dc) which differ by not more than an one order of magnitude. For the first time it is shown that the diffusivity of
C1-C3 alkanes in amorphous and crystalline PMP phases is decreasing in accordance with sequence DCH4 >DC2H6
>DC3H8. A certain scatter of the PMP data published in the literature was noted. Obtained data can be relatively
compared with published ones only for methane: for virgin PMP films we obtained PCH4 = 16.7 Barrer; it is known for the
extrusion PMP films that PCH4 = 14.6 – 19.8 Barrer, for casted PMP films PCH4 = 0.4 – 1.2 Barrer. The values for ethane
and propane in crystalline phase of PMP are obtained for the first time. Evaluation of permeability through crystalline
phase at temperature 313,K shows that PC2H6 = 15 Barrer; PC3H8 = 5 Barrer. For real estimation of the separation
efficiency PMP it is needed an additional research with taking into account the crystallinity and temperature
dependences for diffusivity based on results of this study.

A Study of High Temperature Mixed Ionic-Electronic Conducting (MIEC) Ceramic Membrane Catalytic Reactor with Single-Step Water-Gas-Shift (WGS) Reaction for Hydrogen Production and Separation Elango Balu J.N. Chung1,*

Abstract: The feasibility of a catalytic reactor made of mixed ionic-electronic conducting (MIEC) ceramic membrane as a
significant option to enhance the production of pure H2 from biomass gasification is established. Thin film
SrCe0.7Zr0.2Eu0.1O3-δ (SCZE) membranes supported by a NiO-SrCe0.8Zr0.2O3-δ (NiO-SCZ) tubular structure were
developed and tested in simulated high-temperature steam gasification conditions. The main advantage of this
membrane reactor design is that it acts as a water gas shift (WGS) reactor for more hydrogen production and
simultaneously separates H2 brought in by the feed gas stream and that produced in the membrane. The current process
avoids the need for a two-stage reactor setup requiring WGS and H2 separation independently. The possibility of
sequestering the isolated pure CO2 stream is also a plus to this membrane reactor.
This paper showcases the experimental analysis of a MIEC ceramic membrane reactor, tested at high temperatures
typically found in biomass high-temperature steam gasification systems. Syngas produced from high-temperature
gasification of biomass is a complex mixture of hydrocarbons and steam. The current experiments conducted using the
tubular SCZE membranes exposed to [CO] and [H2O] vapor at 900°C and 1 atm. showed the feasibility of carrying out
WGS reaction and separating hydrogen thus produced in a single pass at gasifier exit conditions .The process described
in this paper has not been reported previously in the literature. The results show that SCZE membranes can consistently
separate the hydrogen produced by maintaining the integrity of the membrane structure at high temperatures. The
overall reactor system efficiency was estimated to be close to 40%.

Determination of CO2 Absorption Kinetics in Amino Acid Salts Solutions Using Membrane Contactors Rui Afonso Sofia Félix

Abstract: The reaction kinetics of CO2 with amines is usually studied using a stirred-cell reactor. This involves the
construction of a sensitive and cumbersome apparatus, used through a lengthy and complicated experimental
procedure. In this work, the feasibility of using an alternative method is assessed, based on the permeation of CO2
through a membrane contactor into the amine-containing solution. A hollow fibre module of polydimethylsiloxane dense
layer supported on a porous polyetherimide layer was initially tested, but membrane resistance to CO2 permeation was
too large to allow liquid resistance to be dominant, and thus the kinetic parameters of the solution could not be
determined. A membrane with lower resistance was then used, a porous polytetrafluoroethylene (PTFE) flat-sheet
membrane, which did allow for liquid resistance to be dominant, and thus permitted the calculation of kinetic parameters
in the reaction system.
The kinetic constants calculated from the data obtained with the permeation experiments performed with the PTFE
membrane were compared with results reported in the literature. The two sets of results show differences, although the
general concentration dependence trends were similar. Similar differences have previously been observed between
works of different authors, and so the method tested should be considered viable.

Theoritical Study of Various Configurations of Membrane Processes for Olefins Separation K. Ghasemzadeh1,* M. Jafari

Abstract: The major purpose of present study, is investigation of the ZIF-8 membrane performance for various
configurations, namely; single stage, series multistage and countercurrent recycle cascade (CRC), during separation of
propylene from propane and other gases. To this aim, a balck-box model was developed using Pro II software vesion 9
and its validation was carried out by comparing the simulation results with experimental data. The results of simulation
validation illustrated a good agreement between theoritical results and experimental data. After simulation validation, for
propylene separation, various configurations of ZIF-8 membrane process (single stage, series multistage and
countercurrent recycle cascade (CRC) multistage) were compared and the best results were achieved for CRC
configuration. In this work, the influence of the some significant operating parameters, namely pressure gradient, feed
molar flow rate and membrane surface area on the performance of ZIF-8 membrane was studied in term of purification
efficiency of propylene. In general, the simulation results showed that the ZIF-8 membrane presents acceptable
performance to produce high purity propylene. It can be concluded that the propylene composition in the permeate side
was decreased by membrane surface area, while the feed flow rate and pressure gradient effects were different.
However, increasing of feed flow rate indicated the enhancement of propylene molar fraction in retentate side and
consequently this result showed decreasing of the membrane performance

Theoretical Understanding of How Solution Properties Govern Nanofiltration Performances Sébastien Déon1,* Patrick Dutournié

Abstract: Mechanisms governing transfer of ions through nanofiltration membranes are complex and it is primordial to
understand how rejection and selectivity performances depend on the properties of the solution. For this purpose, a
knowledge model based on a coupling between equilibrium partitioning induced by steric, electric and dielectric
exclusions and transport inside pores by diffusion, convection and electro-migration is proposed to theoretically discuss
the influence of solution properties on performances. After detailing the physical description of this model, the influence
of ion size on rejection is firstly discussed from simulations obtained in several appropriate cases. Since electrostatic
interactions are known to play a role on ion rejection, the influence of ion valence and concentration is then studied and
different behaviors are brought to light depending on ions considered. Finally, the influence of confinement within
nanopores on water dielectric properties and its consequences for ion separation are also addressed.

A Heat Exchanger Reactor Equipped with Membranes to Produce Dimethyl Ether from Syngas and Methyl Formate and Hydrogen from Methanol A. Bakhtyari A. Darvishi

Abstract: The energy crisis of the century is a motivation to present processes with higher energy efficiency for
production of clean and renewable resources of energy. Hence, a catalytic heat exchanger reactor for production of
dimethyl ether (DME) from syngas, and hydrogen and methyl formate (MF) from methanol is investigated in the present
study. The proposed configuration is equipped with two different membranes for in-situ separation of products. Syngas is
converted to DME through an exothermic reaction and it supplies a part of required energy for the methanol
dehydrogenation reaction. Produced water in the exothermic side and produced hydrogen in the endothermic side are
separated by using appropriate perm-selective membranes. In-situ separation of products makes the equilibrium
reactions proceed toward higher conversion of reactants. A mathematical model based on reasonable assumptions is
developed to evaluate molar and thermal behavior of the configuration. Performance of the system is aimed to enhance
by obtaining optimum operating conditions. In this regard, Genetic Algorithm is applied. Performance of the heat
exchanger double membrane reactor working under optimum conditions (OTMHR) is compared with a heat exchanger
reactor without membrane (THR). OTMHR promotes methanol conversion to MF to %87.2, carbon monoxide conversion
to %95.8 and hydrogen conversion to %64.6.

On the Relationship between the Permeability Parameters of Gases and Vapors of C1-C4 Aliphatic Alcohols in Hydrophobic Polymeric Membranes A. A. Kozlova M.G. Shalygin

Abstract: A correlation approach for the evaluation of permeability, diffusion and solubility coefficients of lower aliphatic
alcohols in polymeric membranes using basic parameters of gas transfer is proposed in this work. Previously published
results of experimental study of water, ethanol and n-butanol vapors transfer in hydrophobic membranes based on
glassy polymers as well as obtained new experimental data on vapor permeability of methanol, n-propanol and gases
were critically reviewed. An attempt to demonstrate correlation of selective gas and vapor transfer parameters of
membranes is made in the present study. The establishment of correlation of permeability of gases and C1-C4 aliphatic
alcohols vapors in hydrophobic polymeric membranes allows to use available methods and data of gas transfer
characteristics of membrane materials and membranes for estimation of the vapor separation properties, e.g., modern
Data Base for gas permeability parameters of polymers can be used for evaluation of the membrane separation potential
in relation to lower aliphatic alcohols. The hydrophobic polymers were selected in order to avoid specific interactions
between alcohols and polymer (such as strong induction, dipole-dipole interactions and H-bond creation). Results
include a preliminary estimation of diffusion coefficients of water and C1-C4 alcohols vapors on the basis of correlation
analysis that was previously proposed for the estimation of gas transport parameters. The proposed approach allows to
explain the observed characteristics of the mentioned vapors permeability in polymeric membranes and to show new
relations of gases and vapors transfer in membranes. It seems that obtained results will be useful for the development of
vapor-phase membrane methods of organic substances separation.

Effect of Mass Transfer Resistance of Polymeric Surfactant on Transport of Metal through Bulk Liquid Membrane Interface Diptendu Das Nil

Abstract: This research work deals with an investigation on the reduction of mass transfer coefficient due to the
presence of polymeric surfactant/ polycondensate layer in the liquid membrane. Mo(VI) is chosen as target species
which are to be removed from feed solution using Bulk Liquid membrane (BLM) in presence of polymeric surfactant and
extractant. Mathematical model is developed for simulation of kinetics of Mo(VI) extraction using BLM. Study reveals that
for efficient Mo(VI) extraction, reduction of stripping rate is not at all desirable. Abil EM 90 is found best suitable
polymeric surfactant as it has least mass transfer resistance of Mo(VI) transport in strip phase. This study is very useful
for selecting suitable polymeric surfactant/ polycondensate layer for stabilising liquid emulsion membrane for metal
extraction/recovery purpose.

Assessment of the SEDE Model: Determination of Membrane Potential and Salt Rejection of a Nanofiltration Membrane Yannick Lanteri Anthony Szymczyk

Abstract: Up to now, the SEDE (Steric Electric and Dielectric Exclusion) model was used to describe solute rejection in
nanofiltration or membrane potential measurements. This model uses four fitting parameters: pore size, thickness to
membrane porosity ratio, volume charge density (X) and dielectric constant of the solution inside pores (εp). Because
these two latter parameters are extremely difficult to measure, an alternative method for assessing the SEDE model was
to study both salt rejections and membrane potentials for a same salt. Experiments were conducted with a NF polyamide
membrane in CaCl2 solutions. In the case of single salt solutions, experimental rejections and membrane potentials can
be described by a number of couples (X, εp) because both electric and dielectric exclusion contribute to reject ions. Only,
one of the couples was found to provide a good description of both experimental rejections and membrane potentials.
The fact that a unique choice for X and εp allows accounting simultaneously for both the salt rejection and the membrane
potential data is an indicator of the global coherence of the SEDE model.

A Review on Membranes for Clinical Treatment and Drug Delivery in Medical Applications Catherine Charcosset* Nil

Abstract: Membrane processes are used extensively in biomedical applications. This state of the art review presents the
main applications including renal kidney, blood filtration, blood oxygenator, artificial liver, artificial pancreas, and drug
delivery devices. For well-established treatments like dialysis, plasmapheresis, and blood oxygenator, the techniques are
summarized by presenting membranes used, devices, configurations and treatments. The artificial liver and the artificial
pancreas are not clinically used and some main aspects related to the development of these devices are given, including
configurations and liver or pancreatic cells. Finally, drug delivery devices based on membranes, which are an important
area in pharmaceutics, are summarized by focusing on diffusion and transdermal delivery systems, as well as colloids
like liposomes and nanocapsules. These colloids with nanometric size are surrounded by a lipidic or polymeric thin
membrane which controls drug transfer to the surrounding medium.

Theoretical Considerations of Pressure Drop and Mass Transfer of Gas Flow in Spiral Wound Membrane Modules M. Metaiche J. Sanchez-Marcano*

Abstract: In this work we give the preliminary results of the development of two reliable correlations for the calculation of
the friction and mass transfer coefficients for the gas transfer through spiral wound membrane modules. The mass
transfer coefficient which allows determining the polarization phenomenon was taken in consideration through the
calculation of the Sherwood number near the surface of the membranes. Both correlations take in consideration the
inclination angle of transversal and longitudinal filaments of grids in spacers. They allow a good prediction of the
pressure drop, friction coefficient and the mass transfer in spiral modules for gas flow when compared with experimental
results obtained in a previous work reported in the literature.

Hybridization of Advanced Oxidation Processes with Membrane Separation for Treatment and Reuse of Industrial Laundry Wastewater Sylwia Mozia Magdalena Janus

Abstract: A new attempt to treat and reuse the industrial laundry wastewater using biological treatment followed by
advanced oxidation processes (AOPs) and membrane separation is presented. Three various configurations of the
hybrid systems were investigated: (1) biological treatment in a Moving Bed Biofilm Reactor (MBBR) – photocatalysis with
suspended TiO2 P25, enhanced with in situ generated O3 – ultrafiltration (UF) – nanofiltration (NF); (2) biological
treatment in MBBR– photocatalysis with immobilized TiO2 P25, enhanced with in situ generated O3 – UF - NF; (3)
biological treatment in MBBR – photolysis/ozonation (with in situ generated O3) – UF – NF. For comparison purpose the
wastewater was additionally treated in the MBBR – UF – NF mode (4). Application of AOPs contributed to the UF
membrane fouling mitigation during treatment of the biologically pretreated laundry wastewater. The highest
improvement of the UF permeate flux was found in case of the MBBR effluent treated with application of the immobilized
TiO2 bed which was attributed to the highest efficiency of mineralization observed for that system. Since the applied
wastewater contained significant amounts of inorganic ions, mainly Na+ and Cl-, the NF as the final polishing step was
proposed. The quality of NF permeate was independent on the AOP mode applied and, moreover, significantly higher
than the quality of water currently used in the laundry. It was concluded that the NF permeate could be recycled to any
stage of the laundry system. Taking into consideration that application of TiO2 increases the overall treatment costs and
that although the O3/UV pretreatment is less efficient than photocatalysis, it still allows to improve the UF permeate flux
for ca. 35% compared to the direct UF of the MBBR effluent, the MBBR – UV/O3 – UF – NF system was proposed as the
most beneficial configuration for the treatment and reuse of the industrial laundry wastewate

Characterization of Metal-Doped Methylated Microporous Silica for Molecular Separations Hany Hassan El-Feky Kelly Briceño

Abstract: Novel silica xerogels are prepared and developed by sol-gel method in the present study. The preparation
involves cobalt-doping within the organic templated silica matrices, where methyltriethoxysilane (MTES), which contains
methyl groups as a covalently bonded organic template is used. The synthesis and surface properties of cobalt-doped
methylated microporous silica xerogels with different MTES and cobalt content are revealed by surface and
microstructural techniques, such as TGA, FTIR, X-ray and N2 adsorption measurements. The doping process enhances
the thermal stability of the silica xerogels up to ~ 560 °C in oxidizing atmosphere. Besides, this process has no significant
effect on the incorporation of the organic template within the silica matrix. As result of the promoted densification of the
xerogels either by increasing MTES content and heat treatment, there is structural change of the silica xerogels such as
decreasing the micropore volume and broadening of the pore size distribution. Heat treatment and increasing the cobalt
oxide content from 5 to 10% weight ratio resulted in samples with approximately the same structural parameters. This
suggests that the cobalt particles are homogeneously dispersed in the silica matrix. The novel silica xerogels exhibit
trend toward micropores formation suggesting that these doped silica xerogels can be precursor materials for molecular
sieve silica membranes applications. Two silica membranes, hydrophobic and cobalt-doped hydrophobic, are prepared
and their performance is examined by the study of transport of He, H2 and N2. Preliminary results show that the
microporous structure obtained in the unsupported cobalt-doped hydrophobic material are preserved after coating inside
the tubular support.

Development of PEBAX Based Membrane for Gas Separation: A Review M.S. Abdul Wahab A.R. Sunarti*

Abstract: Polymer is among the favorite materials used for membrane separation as they are cheap, easily cast, low
maintenance cost and commercially easy to get eventhough the material needs to be altered to meet the separation
industry specific needs. There are two common issues in membrane preparation which are the produced sheet are too
brittle and has no strength to withstand pressure during separation process and the porosity of the sheet sometimes not
suitable with the gas kinetic diameter for the separation to occur. PEBAX or Poly ether block amide is the answer for the
issues as this elastomer provides good mechanical strength from the hard segment of the crystalline poly amide block
while the soft polyether will drive the separation process. This unique material can be casted either by phase inversion of
the PEBAX itself with other polymer or by coating them on the other polymer substrate

Preparation of Polymer Inclusion Membranes (PIMs) with Ionic Liquid and its Application in Dye Adsorption Process Supported by Statistical Analysis D. Shanthana Lakshmi Sergio Santoro

Abstract: Polymer inclusion membranes (PIMs) were prepared via Non-Solvent Induced Phase Separation (NIPS) using
polyethersulfone (PES) loaded with a liquid ionic, 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]).
Hydrophilic porous PIMs with a controlled morphology were obtained and tested for the removal of reactive blue 19
(RB19) as a model anionic dye. The dye adsorption efficiency depends on several variables i.e. pH, contact time, initial
dye concentration, amount and weight of adsorbent (PIMs). The optimal values of these parameters were calculated by
the multivariate approach of “Experimental design” and, in particular, a central composite design (CCD). The optimal
conditions obtained from the response surface data are: [BMIM][PF6] concentration 10.7wt%, pH 3.0, RB19 dye
concentration 10.0 ppm and PIMs of weight 0.055 mg. The experimental adsorption percentage of RB19value (69.2%)
was in agreement to those predicted by the CCD model (71.7%).

Ultrafiltration of Orange Press Liquor: Effect of Operating Conditions on Membrane Fouling and Permeate Flux René Ruby-Figueroa, Carmela Conidi

Abstract: Orange press liquor, a by-product of the orange juice production, was clarified by cross flow ultrafiltration (UF),
on laboratory scale, by using polysulphone hollow fibre membranes with molecular weight cut-off of 100 kDa. The effect
of operating conditions, such as transmembrane pressure, feed flow rate and temperature, on fouling index, total
resistance and permeate flux was investigated.
Analysis of the results revealed that in the range of operating values investigated permeate flux increased with
temperature, pressure and feed flow rate according to concentration polarization models. Total resistance and fouling
index increased with pressure and decreased with feed flow rate. An increase of temperature in the range 15-35 °C
reduced the value of total resistance but enhanced the fouling index.
According to the experimental results the optimum conditions to maximize permeation fluxes were found to be 1.4 bar of
pressure, 35°C and a feed flow rate of 245 L/h; on the other hands, operating conditions of 0.2 bar, 15 °C and 245 L/h
were identified as the best ones to minimize membrane fouling.

Pure Hydrogen Production from Steam Reforming of Bio-Sources G. Bagnato A. Iulianelli

Abstract: Two synthetic mixtures simulating biogas (CH4 /CO2 = 66.2/33.8) and bioethanol (H2O/EtOH = 13/1) have
been used for producing hydrogen by steam reforming reaction in a commercial dense self-supported Pd-Ag membrane
reactor. The experimental campaign was subdivided into two parts. Firstly, we studied biogas steam reforming reaction,
evaluating the reaction pressure influence (between 200 and 350 kPa) at 450°C, H2O/CH4feed molar ratio = 4/1, GHSV
=2370h-1, sweep gas flow rate (N2) = 28.55 mL/min and countercurrent configuration. As best result, we reached 60%
CH4 conversion and 40% hydrogen recovery at 350kPa.
Successively, we carried out bioethanol steam reforming reaction studying the influence of reaction temperature
between 350 and 400°C at 300 kPa of reaction pressure, GHSV=700 h-1 in the presence of sweep gas (N2 = 28.55
mL/min) and countercurrent configuration, obtaining - at 400 °C - maximum ethanol conversion, hydrogen yield and
recovery equal to 70%, 50% and 65%, respectively. In addition, we compared the membrane reactor performance with a
traditional reactor exercised at the same conditions, only varying the reaction pressure between 200 and 300 kPa. The
aim of this work is constituted by the pure hydrogen production from bio-sources exploitation in membrane reactors at
bench scale, starting with the utilization of commercial membranes available in the market and in the perspective of
scaling up the process for potential industrial development.

Membrane Bioreactor in China: A Critical Review Olusegun K. Abass Xing Wu

Abstract: The application of membrane bioreactor (MBR) for wastewater treatment and reuse has received ample
scientific and industrial considerations due to its potential for improved effluent quality, strong anti-shock loading
capacity, less residual sludge and small footprint. Particularly in 2006, since the first operation of a large-scale MBR in
China, it’s acceptability for wastewater reclamation had nearly tripled in recent years. This rigorous review work focus on
the overall operational chain for the MBR system with attention placed on the Chinese MBR market, fouling
characteristics, energy costs, and application trend in China. Recent developments in membrane materials,
compositions, and properties are summarized. Roles of cake-layer formation, extracellular polymeric substances (EPS)
and hydrodynamic effect on membrane fouling are critically assessed. Lastly, future perspective regarding long term
development of MBR applications in China and potential areas of fouling mitigation are identified

Supported Liquid Membrane Composed of Tertiary or/and Quaternary Amine for the Extraction of Lactic Acid B.S. Chanukya Navin K. Rastogi*

Abstract: The present work deals with the extraction of lactic acid from aqueous solution, fermentation broth and
buttermilk by supported liquid membrane. The mixed amine extractant system of tertiary amine (Tri-octyl-amine) and
quaternary amine (AliquatTM 336) in xylene was used in the supported liquid membrane The parameters such as effect of
mixed amine extractant system, its ratios and concentration, stirring speed, strip: feed phase volume, and solute
permeability as well as extraction efficiencies were calculated. The extraction of lactic acid from fermentation broth using
standardised supported liquid membrane conditions showed 17.3% and 31.9% extraction with deionized water and
Na2CO3 solution as the strip phase respectively and from buttermilk: 67 and 65.9% extraction with deionized water and
Na2CO3 solution as the strip phase, respectively. The present study demonstrates the potential of supported liquid
membrane composed of a combination of tertiary amine and quaternary amine as carriers for lactic acid extraction from
aqueous and real systems.

A Comparative Study on Sulfonated PEEK and PVDF Blend Membranes for Direct Methanol Fuel Cells Göknur Dönmez Hüseyin Deligöz

Abstract: Various polymeric blend membranes based on sulfonated poly(ether ether ketone) (sPEEK) and
poly(vinylidene fluoride) (PVDF) are prepared by solution casting method for direct methanol fuel cells (DMFCs).
Physicochemical properties of the membranes are studied after blending sPEEK with PVDF in different ratios. It is found
that the thermal stabilities of all blend membranes are above 200oC which is sufficiently high for use in DMFC. Water
uptake values of the blend membranes vary between 9-20% as a function of the blend composition. Similar to the water
uptake property, proton conductivity values and surface hydrophilicity of the samples increase with sPEEK portion in the
blend. Water uptake of sPEEK30/PVDF70 blend membrane is about 9.2%, the proton conductivity of this membrane is
0.8, and the methanol permeability of sPEEK30/PVDF70 blend membrane is about 1/10 that of untreated
Nafion®117 reported in the literature. Based on the results, it is concluded that the sPEEK/PVDF polymer blends can be
considered as a candidate membrane for DMFC applications considering their controllable properties, cheapness and
easy preparation

Optimal Design of Thermal Membrane Distillation Systems for the Treatment of Shale Gas Flowback Water Nesreen A. Elsayed Maria A. Barrufet

Abstract: Shale gas production is associated with the significant consumption of fresh water and discharge of
wastewater. The flowback wastewater is tied to the hydraulic fracturing technology used for completing and stimulating
the horizontal wells in the very tight formations characterizing the shale formation. Treatment and reuse of these large
volumes of wastewater can lead to substantial savings in fresh water usage and reduction of the negative environmental
impact thereby enhancing sustainability of the shale gas industry. Such treatment requires selective and cost-effective
Thermal membrane distillation (TMD) is an emerging technology that offers several advatanges such as high selectivity
in separating water from inorganic solutes and modular nature that can accommodate a wide range of flows. It can also
utilize low-level heats that are typically available from shale-gas production and processing.
The objective of this work is to develop an optimization approach for the design of TMD systems to treat flowback water.
A multi-period formulation is developed to account for the time-based variation in the flowrate and concentration of the
flowback water. Modeling equations are used to relate design and operating variables to performance and cost. The
optimization formulation also accounts for the period-based changes in the required design and operating variables and
reconciles them over the selected periods. Other constraints include quality of the permeate and water-recovery ratio.
The optimization formulation and design approach are applied to a case study for the treatment of flowback water for the
Marcellus Shale Play. For 75% water recovery, the cost of the permeate is about $2.6/m3. As higher recoveries are
sought, the cost per m3 of permeate increases due to capital productivity factors in dealing with the decreasing amount of
flowback water over time. The results are reported using a Pareto chart that trades off recovery objectives with cost of
treated water.

Hydrogen Production: Overview of Technology Options and Membrane in Auto-Thermal Reforming Including Partial Oxidation and Steam Reforming S. M. Sadati P. Vousoughi

Abstract: Hydrogen, a constituent in many chemical compounds in nature, is a key component for several chemical
processes such as hydrogenation, hydrocracking, and hydrotreating, or even for fuel. On the other hand, Synthesis gas
containing hydrogen, which is one of the most popular intermediate products are used in many industries. There are
many ways for production of hydrogen such as reforming of hydrocarbons (e.g. natural gas), partial oxidation,
autothermal reforming, membrane reactors, and thermal gasification of biomass and waste. In the world, more hydrogen
is produced from natural gas. In this study, several methods of hydrogen production have been considered and all
advantages and disadvantages of listed technologies have been expressed. Finally, according to these points optimum
technology for hydrogen production has been proposed.

Investigation on the Radon Emanation for Domestic Gypsum Boards Cheol Min Lee Yeong Don Kwak

Abstract: The present study investigates radon emissions from commercial gypsum boards currently available on the
domestic market in order to provide accurate information to the public. Gypsum boards that have been manufactured
domestically since 2012 were used for the study. Measurements and analyses were performed using the closedcontainer
method with Nuclear Track Detectors (NRSa), which are long-term passive measuring devices. Of the 19
containers used, 2 were used as background concentration, without inserting samples. The average concentration of
radon within the air of the enclosed container was measured as 28.5 Bq/m3, and the maximum concentration was 132.0
Bq/m3. It was found that the radon emission per unit area of the gypsum boards was 0.0223 ± 0.0258 mBq/m2·h and the
emission per unit weight was 0.0037± 0.0046 mBq/kg·h. Gypsum boards manufactured over a three-year period, from
2012 to 2014, were categorized by one-year terms, and the difference in the radon emission according to the year of
manufacture was examined. It was found that three years of continuous radon emission from building materials did not
cause a natural decrease in the radon exhalation rate. It was also found that there is no difference in the radon
exhalation rate caused by the characteristics of the gypsum boards, that is, by general or waterproof gypsum boards.

Recycling of Polysulfone: Study Properties of Membranes Mayank Saxena Saroj Sharma

Abstract: Many significant developments regarding membranes have been taken place in past few decades. The wet
phase inversion is a simple method to prepare asymmetric polysulfone membranes. Membranes were fabricated from
polysulfone using N,N dimethyl formamide (solvent) and water (non-solvent) and permeation properties were
investigated. We have explored the differences in performances of the membranes prepared from consecutive phase
inversion of polysulfone. The effect of addition of sodium lauryl sulphate and their multi stage phase inversion were also
studied. Functional group ruination/formation, Morphology, hydrophobicity, MWCO were analysed from different
analytical instruments (viz. SEM, FTIR-ATR, TGA, contact angle, GPC). Fourier Transform Infrared (FTIR-ATR) spectra
of polysulfone membranes were analysed to identify the variations of the bonds. The results obtained from water
permeation experiments showed that consecutive phase separation of polysulfone increased the water permeability of
the membranes. The polysulfone membranes resulted from multistage phase separation showed decreasing trend in
separation for polyethylene oxide (PEO, 200kDa) as well as Bovine Serum Albumin (BSA, 66 kDa).

Impact of Coenzyme Q10 on the Physical Properties of Model Lipid Membranes Ajda Ota Marjeta Sentjurc

Abstract: We investigated the influence of coenzyme Q10 on structural changes of model lipid membranes formed by
1,2-dipalmitoyl-sn-glycero-3-phosphocholine and by a mixture of phosphatidylcholine and sphingomyelin (2.4:1).
Structural changes in the membranes were measured using electron paramagnetic resonance and differential scanning
calorimetry. Two spin probes were used to monitor membrane characteristics: MeFASL (10,3) to monitor the changes
close to the water-lipid interface, and MeFASL (2,11) to monitor the changes in the middle of the bilayer of the model
lipid membranes. These data show that perturbation of CoQ10 in the lipid membranes, promotes a decrease in the
dynamics of the lipid acyl chains, i.e., it increases the ordering of the membrane interior. The results from DSC
measurements suggested that the CoQ10 in the bilayer does not significantly perturb the thermal and enthalpic stability of
DPPC (the gel-to-liquid transition does not change) but additionally stabilizes the lipid bilayer due to the aggregation of
CoQ10 within the lipid bilayer. The CoQ10 fraction in an aggregated state increased in proportion to its concentration in the
DPPC multilamellar liposomes.

Evaluation of Performance of Sequential Membranes Used in Pilot Scale Biogas Plant: A Case Study for Laying Hen Manure Duygu Karaalp Elif Aksöyek Pekgüzel

there is significant amount of waste disposal problem. One of the environmental assesment options for the use of this
waste is environmentally friendly biofuel production such as biomethane. High nitrogen content is one of the important
challenges to transform chicken manure to biofuel. For this reason, significant amount of dilution water is required in the
systems using manure as mono substrate and thereby very large storage volumes (storage time 4-6 months) are needed
for the enormous amount of effluent after anaerobic digestion process. These two subjects are threatening the economic
viability of the biogas production. Furthermore, need for dilution water is an economic burden to the businesses in
countries where the water scarcity is a serious concern. On the other hand, integrated use of membrane system offers
possibility of using the digestion effluent as dilution water over and over where nitrogen is removed selectively by
membrane assisted biogas reactor configuration. In this way, significant economy could be provided in the overall project
budget by eliminating the final storage needs as well as water saving. For this purpose, the performance results of a pilot
plant scale membrane system consisting of micro (MF), ultra (UF), nano (NF) and reverse osmosis (RO) membranes are
presented in this study to be used in real scale applications. The feasibility of continuous reuse of digestate as fresh feed
water was suggested. For this purpose, NF90 and X20 type membranes were found to be most effective ones for the
recovery of ammonium (88% and 98%) from the digestate,

Siloxane Diacrylate-based All-Solid Polymer Electrolytes for Lithium Batteries Matteo Destro Claudio Gerbaldi

Abstract: Fully solid polymer electrolyte (SPE) membranes were prepared by UV induced free radical polymerisation
(UV-curing) of acrylated siloxane polyalkyleneoxide copolymers in the presence of different lithium salts. The main chain
contains locally mobile segments of ethoxy groups as part of the copolymer, and these moieties can provide coordination
sites for the mobility of Li+ ions. The materials are produced through a solvent free procedure, and used as ionconducting
media as well as a separator in high temperature lithium-based batteries. The preparation process is easy,
simple and versatile. The final product obtained demonstrates good mechanical integrity due to the highly cross-linked
nature of the polymer network, and wide thermal stability. The membranes are also soft, easy to manage and
transparent. They also exhibit acceptable ionic conductivity and wide electrochemical stability window.

Transportation Characteristics of Bisphenol A Affected by Humic Substances Through Ultrafiltration Membrane with Low Molecule Weight Cut-Off Congcong Tang Wei Zuo

Abstract: The hydrophobic interaction properties between bisphenol A (BPA) and humic substances (HS) were
investigated using an ultrafiltration (UF) membrane with 1000Da Molecule Weight Cut-off (MWCO). Expect for other
influences, the Stokes radius of the hydration molecule of the BPA affected by HS was calculated with the hydrodynamic
model by simulation of BPA transportation in the membrane. It was found that the rejection efficiencies of BPAs visibly
increased in the presence of various HS (humic acid and fulvic acid). Simulation results showed that the effective radius
of the hydration molecules was increased accordingly. It is proposed that the HS addition may improve the
hydrophobicity and hydration of the BPA hydration molecules, which increased the effective radius of the BPA
molecules. This research helps to understand the interaction between hydrophobic molecules and natural organic
matters (NOMs) during the removal of emerging hydrophobic contaminants using a membrane with low MWCO.

Pure Hydrogen Production via Ethanol Steam Reforming Reaction over a Novel Pt-Co Based Catalyst in a Dense Pd-Ag Membrane Reactor (An Experimental Study) A. Basile V. Palma

Abstract: In this work, a novel Co based catalyst containing 10 wt% of Co and 3 wt% of Pt Supported on Al2O3 pellets
coated with CeO2-ZrO2 and Al2O3 was prepared. This catalyst has been utilized in dense Pd-Ag membrane (MR) and
traditional (TR) reactors for ethanol steam reforming (ESR) reaction. In particular, ESR reaction was carried out between
400 and 490 °C and in a pressure range of 100 - 300 kPa with an ethanol/water feed molar ratio of 1/13 and GHSV of
805 h-1. The pressure in shell side of the MR was kept constant at 100 kPa during the whole experimental campaign.
The experimental results in terms of ethanol conversion, hydrogen recovery, flow and yield as well as products
compositions are reported. Moreover, a comparison between MR and TR at 490 °C and the same operating conditions is
realized, pointing out that the MR is able to give higher ethanol conversions and hydrogen yields as well as lower CO
content than the TR in all the reaction tests. The best results were observed at higher temperature and pressure for the
MR and at lower pressure for the TR. By using the aforementioned catalyst, ethanol conversion and hydrogen recovery
of 90% and 67% were achieved respectively at 490 °C and 300 kPa during ESR reaction in the MR, whereas a
conversion of 75% was observed in the TR at the same temperature and at 100 kPa.

Discrimination of Conductance of Lower and Higher Oligomeric Alamethicin Pores Dinara Aliverdieva Dmitry Mamaev1

Abstract: Experimental studies of antimicrobial peptides having a pore-forming mechanism of action have recently
attracted increasing interest due to their broad spectrum of activity and numerous clinical applications. Alamethicin has
been widely studied as an antimicrobial peptide and a model for ion channel-forming proteins. However, the lack of
simple analytical tools for studying mechanisms of interaction of pore-forming peptides and biological membranes at very
low peptide concentrations remains a problem. Here in a short report, we describe an experimental approach for
performing time-dependent discrimination of transmembrane current induced by fractions of lower- and higher-order
oligomeric alamethicin pores using mitochondria.

Synthesis and Characterization of Solid SiO2/P2O5/ZrO2􀀁PVP Membrane for Fuel Cell Applications T. Uma T. Mahalingam

Abstract: A novel polymer network membrane composed by SiO2/P2O5/ZrO2􀀁PVP was prepared to improve the proton
conductivity of PVP membrane. Its physico-chemical properties were characterized using scanning electron microscopy
(SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), and
solid-state nuclear magnetic resonance (NMR). XRD data shows that the crystallinity increases with increase in
concentration of SiO2 and ZrO2. Our results indicate the formation and interconnection of ion clusters. It is observed that
this new membrane exhibits better proton conductivity as compared to the pristine membrane making them suitable for
fuel cell applications.

Biodegradable Barrier Membranes Based on Nanoclays and Carrageenan/Pectin Blends Isabel M. Coelhoso Ana Rita V. Ferreira

Abstract: The aim of this work is the study of the barrier properties of biodegradable membranes based on commercial
pectin and kappa-carrageenan and organically modified nanoclays. Membranes (67% k-carrageenan, 33% pectin) with
different amounts of nanoclays (1, 5 and 10%) were prepared by the solution intercalation method and casting. The films
exhibited enhanced gas and water vapour barrier properties when compared to the ones without nanoclay particles. A
water vapour permeability reduction of 35% for a nanoclay loading of 10 % was observed. The positive impact on the
films’ barrier properties of the organic nanoclay particles inclusion, results from a combined effect of increased tortuosity
and reduction of water sorption due to the hydrophobic nature of the clay. The permeability to carbon dioxide has been
significantly reduced (50% reduction for 1% nanoclay content).
Scanning electron microscopy coupled with energy dispersive X-ray spectroscopy analysis indicated the presence of
under exfoliated nanoclay aggregates at 10%. The membranes have also shown a decrease of their stiffness and an
increase of the elongation at break with the inclusion of nanoclay particles. An attenuation of the membranes
transparency was observed, however, the colour measured after the application of test membranes on coloured paper
sheets, did not change significantly with the inclusion of nanoclay particles.

An Overview on the Bioethanol Production using Membrane Technologies S.M. Sadati.T1 K. Ghasemzadeh

Abstract: Membrane process is a novel effective technology that can improve the efficiency of a bio-refinery plant. In
this study, an overview of the main subjects dealing with the coupling between bioethanol production plant and
membrane process is presented as a new technology. Nowadays, several methods to improve existing processes in
industrial environments are studied. For example, methods such as flow back to increase the efficiency and the use of
more advanced devices has always been a goal of managers. However, using of membranes and membrane processes
can be very efficient and includes a lot of advantages. Indeed, a bio-refinery is one of the suitable choices that can apply
membrane technology to improve the conditions for the biofuel production. To achieve these goals and advantages
being aware of their useful parts is necessary. Frequently, by helping a bio-refinery, sugar is changed into ethanol in one
step using yeast during the fermentation process. Moreover, needed sugars are often provided by Biological sources or
starch, cellulose and lignocellulosic materials. Hence, by changing the type of feedstock, the steps to achieve the
product can be different in the agenda. Therefore, the improvements by the introduction of membranes in the bioethanol
production process are discussed, in terms of efficiency and final product purity

Title Author 1 Author 2 Abstract PDF
Powered by Gravity Forms Directory
Displaying 281 - 320 of 459 1 2 3 4 5 6 7 8 9 10 11 12