WorldWideScience

Sample records for fiber-based adsorbent technology

  1. A novel fiber-based adsorbent technology

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, T.A. [Chemica Technologies, Inc., Bend, OR (United States)

    1997-10-01

    In this Phase I Small Business Innovation Research program, Chemica Technologies, Inc. is developing an economical, robust, fiber-based adsorbent technology for removal of heavy metals from contaminated water. The key innovation is the development of regenerable adsorbent fibers and adsorbent fiber cloths that have high capacity and selectivity for heavy metals and are chemically robust. The process has the potential for widespread use at DOE facilities, mining operations, and the chemical process industry.

  2. Novel Fiber-Based Adsorbent Technology; FINAL

    International Nuclear Information System (INIS)

    Nixon, P.G.; Tsukamoto, T.; Brose, D.J.

    2001-01-01

    The overall of this Department of Energy (DOE) Phase II SBIR program was to develop a new class of highly robust fiber-based adsorbents for recovery of heavy metals from aqueous waste-streams. The fiber-based adsorbents,when commercialized,will be used for clean up metals in aqueous waste-streams emanating from DOE facilities,industry,mining,and groundwater-cleanup operations.The amount of toxic waste released by these streams is of great significance.The U.S.Environment Protection Agency (EPA) reports that in 1990 alone,4.8 billion pounds of toxic chemicals were released into the environment.Of this waste,the metals-containing waste was the second largest contributor,representing 569 million pounds. This report presents the results of the Phase II program,which successfully synthesized noval fiber-based adsorbents for the removal of Group 12 metals(i.e.mercury),Group 14 metals (lead),and Group 10 metals(platinum and palladium) from contaminated groundwater and industrial waste streams.These fiber-based adsorbents are ideally suited for the recovery of metal ions from aqueous waste streams presently not treatable due to the degrading nature of corrosive chemicals or radioactive components in the feed stream. The adsorbents developed in this program rely on chemically resistant and robust carbon fibers and fabrics as supports for metal-ion selective ligands.These adsorbents demonstrate loading capacities and selectivities for metal ions exceeding those of conventional ion-exchange resins.The adsorbents were also used to construct filter modules that demonstrate minimal fouling,minimal compaction,chemical and physical robustness,and regeneration of metal loading capacity without loss of performance

  3. Analysis of Adsorbed Natural Gas Tank Technology

    Science.gov (United States)

    Knight, Ernest; Schultz, Conrad; Rash, Tyler; Dohnke, Elmar; Stalla, David; Gillespie, Andrew; Sweany, Mark; Seydel, Florian; Pfeifer, Peter

    With gasoline being an ever decreasing finite resource and with the desire to reduce humanity's carbon footprint, there has been an increasing focus on innovation of alternative fuel sources. Natural gas burns cleaner, is more abundant, and conforms to modern engines. However, storing compressed natural gas (CNG) requires large, heavy gas cylinders, which limits space and fuel efficiency. Adsorbed natural gas (ANG) technology allows for much greater fuel storage capacity and the ability to store the gas at a much lower pressure. Thus, ANG tanks are much more flexible in terms of their size, shape, and weight. Our ANG tank employs monolithic nanoporous activated carbon as its adsorbent material. Several different configurations of this Flat Panel Tank Assembly (FPTA) along with a Fuel Extraction System (FES) were examined to compare with the mass flow rate demands of an engine.

  4. Fiber-Based, Trace-Gas, Laser Transmitter Technology Development for Space

    Science.gov (United States)

    Stephen, Mark; Yu, Anthony; Chen, Jeffrey; Nicholson, Jeffrey; Engin, Doruk; Mathason, Brian; Wu, Stewart; Allan, Graham; Hasselbrack, William; Gonzalez, Brayler; hide

    2015-01-01

    NASA’s Goddard Space Flight Center (GSFC) is working on maturing the technology readiness of a laser transmitter designed for use in atmospheric CO2 remote-sensing. GSFC has been developing an airplane-based CO2 lidar instrument over several years to demonstrate the efficacy of the instrumentation and measurement technique and to link the science models to the instrument performance. The ultimate goal is to make space-based satellite measurements with global coverage. In order to accomplish this, we must demonstrate the technology readiness and performance of the components as well as demonstrate the required power-scaling to make the link with the required signal-to-noise-ratio (SNR). To date, all the instrument components have been shown to have the required performance with the exception of the laser transmitter.In this program we are working on a fiber-based master oscillator power amplifier (MOPA) laser transmitter architecture where we will develop a ruggedized package and perform the relevant environmental tests to demonstrate TRL-6. In this paper we will review our transmitter architecture and progress on the performance and packaging of the laser transmitter.

  5. Adsorbent Alkali Conditioning for Uranium Adsorption from Seawater. Adsorbent Performance and Technology Cost Evaluation

    International Nuclear Information System (INIS)

    Tsouris, Costas; Mayes, Richard T.; Janke, Christopher James; Dai, Sheng; Das, S.; Liao, W.P.; Kuo, Li-Jung; Wood, Jordana; Gill, Gary; Byers, Maggie Flicker; Schneider, Eric

    2015-01-01

    The Fuel Resources program of the Fuel Cycle Research and Development program of the Office of Nuclear Energy (NE) is focused on identifying and implementing actions to assure that nuclear fuel resources are available in the United States. An immense source of uranium is seawater, which contains an estimated amount of 4.5 billion tonnes of dissolved uranium. This unconventional resource can provide a price cap and ensure centuries of uranium supply for future nuclear energy production. NE initiated a multidisciplinary program with participants from national laboratories, universities, and research institutes to enable technical breakthroughs related to uranium recovery from seawater. The goal is to develop advanced adsorbents to reduce the seawater uranium recovery technology cost and uncertainties. Under this program, Oak Ridge National Laboratory (ORNL) has developed a new amidoxime-based adsorbent of high surface area, which tripled the uranium capacity of leading Japanese adsorbents. Parallel efforts have been focused on the optimization of the physicochemical and operating parameters used during the preparation of the adsorbent for deployment. A set of parameters that need to be optimized are related to the conditioning of the adsorbent with alkali solution, which is necessary prior to adsorbent deployment. Previous work indicated that alkali-conditioning parameters significantly affect the adsorbent performance. Initiated in 2014, this study had as a goal to determine optimal parameters such as base type and concentration, temperature, and duration of conditioning that maximize the uranium adsorption performance of amidoxime functionalized adsorbent, while keeping the cost of uranium production low. After base-treatment at various conditions, samples of adsorbent developed at ORNL were tested in this study with batch simulated seawater solution of 8-ppm uranium concentration, batch seawater spiked with uranium nitrate at 75-100 ppb uranium, and continuous

  6. Adsorbent Alkali Conditioning for Uranium Adsorption from Seawater. Adsorbent Performance and Technology Cost Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Tsouris, Costas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mayes, Richard T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Janke, Christopher James [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dai, Sheng [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Das, S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liao, W. -P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kuo, Li-Jung [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wood, Jordana [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gill, Gary [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Byers, Maggie Flicker [Univ. of Texas, Austin, TX (United States); Schneider, Eric [Univ. of Texas, Austin, TX (United States)

    2015-09-30

    The Fuel Resources program of the Fuel Cycle Research and Development program of the Office of Nuclear Energy (NE) is focused on identifying and implementing actions to assure that nuclear fuel resources are available in the United States. An immense source of uranium is seawater, which contains an estimated amount of 4.5 billion tonnes of dissolved uranium. This unconventional resource can provide a price cap and ensure centuries of uranium supply for future nuclear energy production. NE initiated a multidisciplinary program with participants from national laboratories, universities, and research institutes to enable technical breakthroughs related to uranium recovery from seawater. The goal is to develop advanced adsorbents to reduce the seawater uranium recovery technology cost and uncertainties. Under this program, Oak Ridge National Laboratory (ORNL) has developed a new amidoxime-based adsorbent of high surface area, which tripled the uranium capacity of leading Japanese adsorbents. Parallel efforts have been focused on the optimization of the physicochemical and operating parameters used during the preparation of the adsorbent for deployment. A set of parameters that need to be optimized are related to the conditioning of the adsorbent with alkali solution, which is necessary prior to adsorbent deployment. Previous work indicated that alkali-conditioning parameters significantly affect the adsorbent performance. Initiated in 2014, this study had as a goal to determine optimal parameters such as base type and concentration, temperature, and duration of conditioning that maximize the uranium adsorption performance of amidoxime functionalized adsorbent, while keeping the cost of uranium production low. After base-treatment at various conditions, samples of adsorbent developed at ORNL were tested in this study with batch simulated seawater solution of 8-ppm uranium concentration, batch seawater spiked with uranium nitrate at 75-100 ppb uranium, and continuous

  7. Preparation of metal adsorbents from chitin/chitosan by radiation technology

    International Nuclear Information System (INIS)

    Nguyen Van Suc; Nguyen Quoc Hien; Ngo Quang Huy; Thai My Phe; Dao Van Hoang; Nguyen Van Hung

    2004-01-01

    The methods of preparation of metal adsorbents basing on chitin/chitosan were developed. That include the adsorbent from chitin grafted with acrylic acid by different irradiation doses; the clinging chitosan gel beads; the coagulable solution and the chitosan composite filter. The process of metal adsorption for each adsorbent was studied as adsorption kinetic, isothermal adsorption. The results have been applied for removal of some elements as Hg, Pb, Cd, U, Cu, ect. in the wastewater. (NHA)

  8. Comparison of pre and post-combustion CO{sub 2} adsorbent technologies

    Energy Technology Data Exchange (ETDEWEB)

    T.C. Drage; A. Arenillas; K. Smith; C.E. Snape [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, School of Chemical, Environmental and Mining Engineering

    2006-07-01

    Adsorption is considered to be one of the most promising techniques for the capture of CO{sub 2} from flue gases. The application of adsorption to both post-combustion capture at pressures close to ambient and for high pressure pre-combustion capture applications, for example IGCC, are explored. Adsorption capacities as a function of adsorbent properties as well as strategies for regeneration, both thermal swing and pressure swing are described. Adsorption at both low and high pressures requires chemical and physical adsorbents respectively. Adsorption at high pressure has the advantage of potential temperature swing regeneration whilst maintaining CO{sub 2} pressure, reducing the overall costs associated with re-compression of the gas for transportation.

  9. Improved of Natural Gas Storage with Adsorbed Natural Gas (ANG) Technology Using Activated Carbon from Plastic Waste Polyethylene Terepthalate

    Science.gov (United States)

    Yuliusman; Nasruddin; Sanal, A.; Bernama, A.; Haris, F.; Hardhi, M.

    2017-07-01

    Indonesia imports high amount of Fuel Oil. Although Indonesia has abundant amount of natural gas reserve, the obstacle lies within the process of natural gas storage itself. In order to create a safe repository, the ANG (Adsorbed Natural Gas) technology is planned. ANG technology in itself has been researched much to manufacture PET-based activated carbon for natural gas storage, but ANG still has several drawbacks. This study begins with making preparations for the equipment and materials that will be used, by characterizing the natural gas, measuring the empty volume, and degassing. The next step will be to examine the adsorption process. The maximum storage capacity obtained in this study for a temperature of 27°C and pressure of 35 bar is 0.0586 kg/kg, while for the desorption process, a maximum value for desorption efficiency was obtained on 35°C temperature with a value of 73.39%.

  10. Modeling adsorption: Investigating adsorbate and adsorbent properties

    Science.gov (United States)

    Webster, Charles Edwin

    1999-12-01

    Surface catalyzed reactions play a major role in current chemical production technology. Currently, 90% of all chemicals are produced by heterogeneously catalyzed reactions. Most of these catalyzed reactions involve adsorption, concentrating the substrate(s) (the adsorbate) on the surface of the solid (the adsorbent). Pore volumes, accessible surface areas, and the thermodynamics of adsorption are essential in the understanding of solid surface characteristics fundamental to catalyst and adsorbent screening and selection. Molecular properties such as molecular volumes and projected molecular areas are needed in order to convert moles adsorbed to surface volumes and areas. Generally, these molecular properties have been estimated from bulk properties, but many assumptions are required. As a result, different literature values are employed for these essential molecular properties. Calculated molar volumes and excluded molecular areas are determined and tabulated for a variety of molecules. Molecular dimensions of molecules are important in the understanding of molecular exclusion as well as size and shape selectivity, diffusion, and adsorbent selection. Molecular dimensions can also be used in the determination of the effective catalytic pore size of a catalyst. Adsorption isotherms, on zeolites, (crystalline mineral oxides) and amorphous solids, can be analyzed with the Multiple Equilibrium Analysis (MEA) description of adsorption. The MEA produces equilibrium constants (Ki), capacities (ni), and thermodynamic parameters (enthalpies, ΔHi, and entropies, ΔSi) of adsorption for each process. Pore volumes and accessible surface areas are calculated from the process capacities. Adsorption isotherms can also be predicted for existing and new adsorbate-adsorbent systems with the MEA. The results show that MEA has the potential of becoming a standard characterization method for microporous solids that will lead to an increased understanding of their behavior in gas

  11. Fiber-based monolithic columns for liquid chromatography.

    Science.gov (United States)

    Ladisch, Michael; Zhang, Leyu

    2016-10-01

    Fiber-based monoliths for use in liquid chromatographic separations are defined by columns packed with aligned fibers, woven matrices, or contiguous fiber structures capable of achieving rapid separations of proteins, macromolecules, and low molecular weight components. A common denominator and motivating driver for this approach, first initiated 25 years ago, was reducing the cost of bioseparations in a manner that also reduced residence time of retained components while achieving a high ratio of mass to momentum transfer. This type of medium, when packed into a liquid chromatography column, minimized the fraction of stagnant liquid and resulted in a constant plate height for non-adsorbing species. The uncoupling of dispersion from eluent flow rate enabled the surface chemistry of the stationary phase to be considered separately from fluid transport phenomena and pointed to new ways to apply chemistry for the engineering of rapid bioseparations. This paper addresses developments and current research on fiber-based monoliths and explains how the various forms of this type of chromatographic stationary phase have potential to provide new tools for analytical and preparative scale separations. The different stationary phases are discussed, and a model that captures the observed constant plate height as a function of mobile phase velocity is reviewed. Methods that enable hydrodynamically stable fiber columns to be packed and operated over a range of mobile phase flow rates, together with the development of new fiber chemistries, are shown to provide columns that extend the versatility of liquid chromatography using monoliths, particularly at the preparative scale. Graphical Abstract Schematic representation of a sample mixture being separated by a rolled-stationary phase column, resulting separated peaks shown in the chromatogram.

  12. Fiber-based laser MOPA transmitter packaging for space environment

    Science.gov (United States)

    Stephen, Mark; Yu, Anthony; Chen, Jeffrey; Numata, Kenji; Wu, Stewart; Gonzales, Brayler; Han, Lawrence; Fahey, Molly; Plants, Michael; Rodriguez, Michael; Allan, Graham; Abshire, James; Nicholson, Jeffrey; Hariharan, Anand; Mamakos, William; Bean, Brian

    2018-02-01

    NASA's Goddard Space Flight Center has been developing lidar to remotely measure CO2 and CH4 in the Earth's atmosphere. The ultimate goal is to make space-based satellite measurements with global coverage. We are working on maturing the technology readiness of a fiber-based, 1.57-micron wavelength laser transmitter designed for use in atmospheric CO2 remote-sensing. To this end, we are building a ruggedized prototype to demonstrate the required power and performance and survive the required environment. We are building a fiber-based master oscillator power amplifier (MOPA) laser transmitter architecture. The laser is a wavelength-locked, single frequency, externally modulated DBR operating at 1.57-micron followed by erbium-doped fiber amplifiers. The last amplifier stage is a polarization-maintaining, very-large-mode-area fiber with 1000 μm2 effective area pumped by a Raman fiber laser. The optical output is single-frequency, one microsecond pulses with >450 μJ pulse energy, 7.5 KHz repetition rate, single spatial mode, and < 20 dB polarization extinction.

  13. Black Sprayable Molecular Adsorber Coating

    Data.gov (United States)

    National Aeronautics and Space Administration — The main objective of this technology project is to develop, optimize, and flight qualify a black version of the molecular adsorber coating and a conductive version...

  14. Fundamental aspects of plating technology. 5. The effect of strongly adsorbed species on the morphology of metal deposits

    Energy Technology Data Exchange (ETDEWEB)

    Popov, K I; Rodaljevic, Z P; Krstajic, N V; Novakovic, S D

    1985-07-01

    It is shown that the improvement in the quality of electrodeposits obtained from CdSO/sub 4/ solution in the presence of strongly adsorbed species compared with that of deposits obtained in the absence of such species is due to a decrease in the exchange current density and an increase in the Tafel slope for the deposition process in the former case.

  15. Adsorber fires

    International Nuclear Information System (INIS)

    Holmes, W.

    1987-01-01

    The following conclusions are offered with respect to activated charcoal filter systems in nuclear power plants: (1) The use of activated charcoal in nuclear facilities presents a potential for deep-seated fires. (2) The defense-in-depth approach to nuclear fire safety requires that if an ignition should occur, fires must be detected quickly and subsequently suppressed. (3) Deep-seated fires in charcoal beds are difficult to extinguish. (4) Automatic water sprays can be used to extinguish fires rapidly and reliably when properly introduced into the burning medium. The second part of the conclusions offered are more like challenges: (1) The problem associated with inadvertent actuations of fire protection systems is not a major one, and it can be reduced further by proper design review, installation, testing, and maintenance. Eliminating automatic fire extinguishing systems for the protection of charcoal adsorbers is not justified. (2) Removal of automatic fire protection systems due to fear of inadvertent fire protection system operation is a case of treating the effect rather than the cause. On the other hand, properly maintaining automatic fire protection systems will preserve the risk of fire loss at acceptable levels while at the same time reducing the risk of damage presented by inadvertent operation of fire protection systems

  16. Fiber-Based Adsorbents Tailored for PLSS Ammonia and Formaldehyde Removal, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of advanced lightweight Trace Contaminant Control (TCC) filters plays an important role in removing ammonia and formaldehyde contaminants?both those...

  17. Fiber-based adsorbents tailored for PLSS ammonia and formaldehyde removal, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of an advanced lightweight Trace Contaminant Control filter will play a critical role in the viability of life support systems for future space and...

  18. Fiber-based wearable electronics: a review of materials, fabrication, devices, and applications.

    Science.gov (United States)

    Zeng, Wei; Shu, Lin; Li, Qiao; Chen, Song; Wang, Fei; Tao, Xiao-Ming

    2014-08-20

    Fiber-based structures are highly desirable for wearable electronics that are expected to be light-weight, long-lasting, flexible, and conformable. Many fibrous structures have been manufactured by well-established lost-effective textile processing technologies, normally at ambient conditions. The advancement of nanotechnology has made it feasible to build electronic devices directly on the surface or inside of single fibers, which have typical thickness of several to tens microns. However, imparting electronic functions to porous, highly deformable and three-dimensional fiber assemblies and maintaining them during wear represent great challenges from both views of fundamental understanding and practical implementation. This article attempts to critically review the current state-of-arts with respect to materials, fabrication techniques, and structural design of devices as well as applications of the fiber-based wearable electronic products. In addition, this review elaborates the performance requirements of the fiber-based wearable electronic products, especially regarding the correlation among materials, fiber/textile structures and electronic as well as mechanical functionalities of fiber-based electronic devices. Finally, discussions will be presented regarding to limitations of current materials, fabrication techniques, devices concerning manufacturability and performance as well as scientific understanding that must be improved prior to their wide adoption. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. The Use of the Molecular Adsorber Coating Technology to Mitigate Vacuum Chamber Contamination During Pathfinder Testing for the James Webb Space Telescope

    Science.gov (United States)

    Abraham, Nithin S.; Hasegawa, Mark M.; Wooldridge, Eve M.; Henderson-Nelson, Kelly A.

    2016-01-01

    As a coating made of highly porous zeolite materials, the Molecular Adsorber Coating (MAC) was developed to capture outgassed molecular contaminants, such as hydrocarbons and silicones. For spaceflight applications, the adsorptive capabilities of the coating can alleviate on-orbit outgassing concerns on or near sensitive surfaces and instruments within the spacecraft. Similarly, this sprayable paint technology has proven to be significantly beneficial for ground based space applications, in particular, for vacuum chamber environments. This paper describes the recent use of the MAC technology during Pathfinder testing of the Optical Ground Support Equipment (OGSE) for the James Webb Space Telescope (JWST) at NASA Johnson Space Center (JSC). The coating was used as a mitigation tool to entrap persistent outgassed contaminants, specifically silicone based diffusion pump oil, from within JSC's cryogenic optical vacuum chamber test facility called Chamber A. This paper summarizes the sample fabrication, installation, laboratory testing, post-test chemical analysis results, and future plans for the MAC technology, which was effectively used to protect the JWST test equipment from vacuum chamber contamination.

  20. Fiber-Based Lasers as an Option for GRACE Follow-On Light Source

    Science.gov (United States)

    Camp, Jordan

    2010-01-01

    Fiber based lasers offer a number of attractive characteristics for space application: state of the art laser technology, leverage of design and reliability from the substantial investments of the telecon industry, and convenient redundancy of higher risk components through fiber splicing. At NASA/Goddard we are currently investigating three GFO fiber-based laser options: a fiber oscillator built in our laboratory; an effort to space qualify a commercial design that uses a proprietary high-gain fiber cavity; and the space qualification of a promising new commercial external cavity laser, notable for its low-mass, compact design. In my talk I will outline these efforts, and suggest that the GFO Project may soon have the option of a US laser vendor for its light source.

  1. Krypton retention on solid adsorbents

    International Nuclear Information System (INIS)

    Monson, P.R. Jr.

    1982-01-01

    An experimental laboratory program was conducted to develop economical solid adsorbents for the retention of krypton from a dissolver off-gas stream. The study indicates that a solid adsorbent system is feasible and competitive with other developing systems which utilize fluorocarbon absorption nd cryogenic distillation. This technology may have potential applications not only in nuclear fuel reprocessing plants, but also in nuclear reactors and in environmental monitoring. Of the 13 prospective adsorbents evaluated with respect to adsorption capacity and cost, the commercially available hydrogen mordenite was the most cost-effective material at subambient temperatures (-40 0 to -80 0 C). Silver mordenite has a higher capacity for krypton retention, but is 50 times more expensive than hydrogen mordenite

  2. Black Sprayable Molecular Adsorber Coating Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The main objective of this technology project is to develop, optimize, and flight qualify a black version of the molecular adsorber coating and a conductive version...

  3. Qualification testing of fiber-based laser transmitters and on-orbit validation of a commercial laser system

    Science.gov (United States)

    Wright, M. W.; Wilkerson, M. W.; Tang, R. R.

    2017-11-01

    Qualification testing of fiber based laser transmitters is required for NASA's Deep Space Optical Communications program to mature the technology for space applications. In the absence of fully space qualified systems, commercial systems have been investigated in order to demonstrate the robustness of the technology. To this end, a 2.5 W fiber based laser source was developed as the transmitter for an optical communications experiment flown aboard the ISS as a part of a technology demonstration mission. The low cost system leveraged Mil Standard design principles and Telcordia certified components to the extent possible and was operated in a pressure vessel with active cooling. The laser was capable of high rate modulation but was limited by the mission requirements to 50 Mbps for downlinking stored video from the OPALS payload, externally mounted on the ISS. Environmental testing and space qualification of this unit will be discussed along with plans for a fully space qualified laser transmitter.

  4. Polarimetry noise in fiber-based optical coherence tomography instrumentation

    Science.gov (United States)

    Zhang, Ellen Ziyi; Vakoc, Benjamin J.

    2011-01-01

    High noise levels in fiber-based polarization-sensitive optical coherence tomography (PS-OCT) have broadly limited its clinical utility. In this study we investigate contribution of polarization mode dispersion (PMD) to the polarimetry noise. We develop numerical models of the PS-OCT system including PMD and validate these models with empirical data. Using these models, we provide a framework for predicting noise levels, for processing signals to reduce noise, and for designing an optimized system. PMID:21935044

  5. Sapphire-fiber-based distributed high-temperature sensing system.

    Science.gov (United States)

    Liu, Bo; Yu, Zhihao; Hill, Cary; Cheng, Yujie; Homa, Daniel; Pickrell, Gary; Wang, Anbo

    2016-09-15

    We present, for the first time to our knowledge, a sapphire-fiber-based distributed high-temperature sensing system based on a Raman distributed sensing technique. High peak power laser pulses at 532 nm were coupled into the sapphire fiber to generate the Raman signal. The returned Raman Stokes and anti-Stokes signals were measured in the time domain to determine the temperature distribution along the fiber. The sensor was demonstrated from room temperature up to 1200°C in which the average standard deviation is about 3.7°C and a spatial resolution of about 14 cm was achieved.

  6. All-plastic fiber-based pressure sensor

    DEFF Research Database (Denmark)

    Bundalo, Ivan-Lazar; Lwin, Richard; Leon-Saval, Sergio

    2016-01-01

    We present a feasibility study and a prototype of an all-plastic fiber-based pressure sensor. The sensor is based on long period gratings inscribed for the first time to the best of our knowledge by a CO2 laser in polymethyl methacrylate (PMMA) microstructured fibers and coupled to a pod......-like transducer that converts pressure to strain. The sensor prototype was characterized for pressures up to 150 mbars, and various parameters related to its construction were also characterized in order to enhance sensitivity. We consider this sensor in the context of future applications in endoscopic pressure...... sensors....

  7. Regenerative adsorbent heat pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1991-01-01

    A regenerative adsorbent heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system and at least a portion of the heat of adsorption. A series of at least four compressors containing an adsorbent is provided. A large amount of heat is transferred from compressor to compressor so that heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

  8. Black molecular adsorber coatings for spaceflight applications

    Science.gov (United States)

    Abraham, Nithin S.; Hasegawa, Mark M.; Straka, Sharon A.

    2014-09-01

    The molecular adsorber coating is a new technology that was developed to mitigate the risk of on-orbit molecular contamination on spaceflight missions. The application of this coating would be ideal near highly sensitive, interior surfaces and instruments that are negatively impacted by outgassed molecules from materials, such as plastics, adhesives, lubricants, epoxies, and other similar compounds. This current, sprayable paint technology is comprised of inorganic white materials made from highly porous zeolite. In addition to good adhesion performance, thermal stability, and adsorptive capability, the molecular adsorber coating offers favorable thermal control characteristics. However, low reflectivity properties, which are typically offered by black thermal control coatings, are desired for some spaceflight applications. For example, black coatings are used on interior surfaces, in particular, on instrument baffles for optical stray light control. Similarly, they are also used within light paths between optical systems, such as telescopes, to absorb light. Recent efforts have been made to transform the white molecular adsorber coating into a black coating with similar adsorptive properties. This result is achieved by optimizing the current formulation with black pigments, while still maintaining its adsorption capability for outgassing control. Different binder to pigment ratios, coating thicknesses, and spray application techniques were explored to develop a black version of the molecular adsorber coating. During the development process, coating performance and adsorption characteristics were studied. The preliminary work performed on black molecular adsorber coatings thus far is very promising. Continued development and testing is necessary for its use on future contamination sensitive spaceflight missions.

  9. Transporting method for adsorbing tower and the adsorbing tower

    International Nuclear Information System (INIS)

    Shimokawa, Nobuhiro.

    1996-01-01

    A cylindrical plastic bag is disposed to the upper surface of an adsorbing tower so as to surround a suspending piece. One opening of the bag is sealed, and other opening is secured in a sealed state to a bag holding portion disposed to glove box at a gate for the adsorbing tower box. The adsorbing tower is transported into the glove box, and after the completion of the operation of the adsorbing tower, the adsorbing tower is taken out in a state that the bag is restricted and sealed at a portion below the adsorbing tower. The bag may be made of a vinyl plastic, the bag holding portion may be a short-cylindrical protrusion, and may have an O-ring groove at the outer surface. Even if the adsorbing tower is heavy, the adsorbing tower can be carried out easily in a state where it is sealed gas tightly. (N.H.)

  10. Single bank NOx adsorber for heavy duty diesel engines

    NARCIS (Netherlands)

    Genderen, M. van; Aken, M.G. van

    2003-01-01

    In a NOx adsorber programme the feasibility for applying this technology to heavy duty diesel engines was investigated. After modelling and simulations for realising best λ < 1 engine conditions a platform was build which was used to obtain good NOx adsorber regeneration settings in a number of

  11. The state of physically adsorbed substances in microporous adsorbents

    International Nuclear Information System (INIS)

    Fomkin, A.A.

    1987-01-01

    Xe, Kr, Ar, CF 3 Cl, CH 4 adsorption in NaX microporous zeolite of 0.98 Na 2 OxAl 2 O 3 x2.36SiO 2 x0.02H 2 O is studied. Some properties of adsorbates (density, coefficients of expansion, enthalpy, heat capacity) are determined and discussed. The adsorbate in the microporous adsorbent is shown to be a particular state of a substance. Liniarity of adsorption isosteres and sharp changes during isosteric heat capacity of the adsorbate points to the fact that in microporous adsorbents phase transformations of the second type are possible

  12. Orientational epitaxy in adsorbed monolayers

    International Nuclear Information System (INIS)

    Novaco, A.D.; McTague, J.P.

    1977-01-01

    The ground state for adsorbed monolayers on crystalline substrates is shown to involve a definite relative orientation of the substrate and adsorbate crystal axes, even when the relative lattice parameters are incommensurate. The rotation angle which defines the structure of the monolayer-substrate system is determined by the competition between adsorbate-substrate and adsorbate-adsorbate energy terms, and is generally not a symmetry angle. Numerical predictions are presented for the rare gas-graphite systems, whose interaction potentials are rather well known. Recent LEED data for some of these systems appear to corroborate these predictions

  13. Dataset on photonic crystal fiber based chemical sensor.

    Science.gov (United States)

    Ahmed, Kawsar; Paul, Bikash Kumar; Chowdhury, Sawrab; Islam, Md Shadidul; Sen, Shuvo; Islam, Md Ibadul; Asaduzzaman, Sayed; Bahar, Ali Newaz; Miah, Mohammad Badrul Alam

    2017-06-01

    This article represents the data set of micro porous core photonic crystal fiber based chemical sensor. The suggested structure is folded cladding porous shaped with circular air hole. Here is investigated four distinctive parameters including relative sensitivity, confinement loss, numerical aperture (NA), and effective area ( A eff). The numerical outcomes are computed over the E+S+C+L+U communication band. The useable sensed chemicals are methanol, ethanol, propanol, butanol, and pentanol whose are lies in the alcohol series (Paul et al., 2017) [1]. Furthermore, V -parameter ( V ), Marcuse spot size (MSS), and beam divergence (BD) are also investigated rigorously. All examined results have been obtained using finite element method based simulation software COMSOL Multiphysics 4.2 versions with anisotropic circular perfectly matched layer (A-CPML). The proposed PCF shows the high NA from 0.35 to 0.36; the low CL from ~10 -11 to ~10 -7  dB/m; the high A eff from 5.50 to 5.66 µm 2 ; the MSS from 1.0 to 1.08 µm; the BD from 0.43 to 0.46 rad at the controlling wavelength λ = 1.55 µm for employing alcohol series respectively.

  14. Dataset on photonic crystal fiber based chemical sensor

    Directory of Open Access Journals (Sweden)

    Kawsar Ahmed

    2017-06-01

    Full Text Available This article represents the data set of micro porous core photonic crystal fiber based chemical sensor. The suggested structure is folded cladding porous shaped with circular air hole. Here is investigated four distinctive parameters including relative sensitivity, confinement loss, numerical aperture (NA, and effective area (Aeff. The numerical outcomes are computed over the E+S+C+L+U communication band. The useable sensed chemicals are methanol, ethanol, propanol, butanol, and pentanol whose are lies in the alcohol series (Paul et al., 2017 [1]. Furthermore, V-parameter (V, Marcuse spot size (MSS, and beam divergence (BD are also investigated rigorously. All examined results have been obtained using finite element method based simulation software COMSOL Multiphysics 4.2 versions with anisotropic circular perfectly matched layer (A-CPML. The proposed PCF shows the high NA from 0.35 to 0.36; the low CL from ~10–11 to ~10−7 dB/m; the high Aeff from 5.50 to 5.66 µm2; the MSS from 1.0 to 1.08 µm; the BD from 0.43 to 0.46 rad at the controlling wavelength λ = 1.55 µm for employing alcohol series respectively.

  15. Inorganic chemically active adsorbents (ICAAs)

    Energy Technology Data Exchange (ETDEWEB)

    Ally, M.R. [Oak Ridge National Lab., TN (United States); Tavlarides, L.

    1997-10-01

    Oak Ridge National Laboratory (ORNL) researchers are developing a technology that combines metal chelation extraction technology and synthesis chemistry. They begin with a ceramic substrate such as alumina, titanium oxide or silica gel because they provide high surface area, high mechanical strength, and radiolytic stability. One preparation method involves silylation to hydrophobize the surface, followed by chemisorption of a suitable chelation agent using vapor deposition. Another route attaches newly designed chelating agents through covalent bonding by the use of coupling agents. These approaches provide stable and selective, inorganic chemically active adsorbents (ICAAs) tailored for removal of metals. The technology has the following advantages over ion exchange: (1) higher mechanical strength, (2) higher resistance to radiation fields, (3) higher selectivity for the desired metal ion, (4) no cation exchange, (5) reduced or no interference from accompanying anions, (6) faster kinetics, and (7) easy and selective regeneration. Target waste streams include metal-containing groundwater/process wastewater at ORNL`s Y-12 Plant (multiple metals), Savannah River Site (SRS), Rocky Flats (multiple metals), and Hanford; aqueous mixed wastes at Idaho National Engineering Laboratory (INEL); and scrubber water generated at SRS and INEL. Focus Areas that will benefit from this research include Mixed Waste, and Subsurface Contaminants.

  16. High performance Mo adsorbent PZC

    Energy Technology Data Exchange (ETDEWEB)

    Anon,

    1998-10-01

    We have developed Mo adsorbents for natural Mo(n, {gamma}){sup 99}Mo-{sup 99m}Tc generator. Among them, we called the highest performance adsorbent PZC that could adsorb about 250 mg-Mo/g. In this report, we will show the structure, adsorption mechanism of Mo, and the other useful properties of PZC when you carry out the examination of Mo adsorption and elution of {sup 99m}Tc. (author)

  17. Nano-yarn carbon nanotube fiber based enzymatic glucose biosensor

    International Nuclear Information System (INIS)

    Zhu Zhigang; Burugapalli, Krishna; Moussy, Francis; Song, Wenhui; Li Yali; Zhong Xiaohua

    2010-01-01

    A novel brush-like electrode based on carbon nanotube (CNT) nano-yarn fiber has been designed for electrochemical biosensor applications and its efficacy as an enzymatic glucose biosensor demonstrated. The CNT nano-yarn fiber was spun directly from a chemical-vapor-deposition (CVD) gas flow reaction using a mixture of ethanol and acetone as the carbon source and an iron nano-catalyst. The fiber, 28 μm in diameter, was made of bundles of double walled CNTs (DWNTs) concentrically compacted into multiple layers forming a nano-porous network structure. Cyclic voltammetry study revealed a superior electrocatalytic activity for CNT fiber compared to the traditional Pt-Ir coil electrode. The electrode end tip of the CNT fiber was freeze-fractured to obtain a unique brush-like nano-structure resembling a scale-down electrical 'flex', where glucose oxidase (GOx) enzyme was immobilized using glutaraldehyde crosslinking in the presence of bovine serum albumin (BSA). An outer epoxy-polyurethane (EPU) layer was used as semi-permeable membrane. The sensor function was tested against a standard reference electrode. The sensitivities, linear detection range and linearity for detecting glucose for the miniature CNT fiber electrode were better than that reported for a Pt-Ir coil electrode. Thermal annealing of the CNT fiber at 250 deg. C for 30 min prior to fabrication of the sensor resulted in a 7.5 fold increase in glucose sensitivity. The as-spun CNT fiber based glucose biosensor was shown to be stable for up to 70 days. In addition, gold coating of the electrode connecting end of the CNT fiber resulted in extending the glucose detection limit to 25 μM. To conclude, superior efficiency of CNT fiber for glucose biosensing was demonstrated compared to a traditional Pt-Ir sensor.

  18. Nano-yarn carbon nanotube fiber based enzymatic glucose biosensor

    Science.gov (United States)

    Zhu, Zhigang; Song, Wenhui; Burugapalli, Krishna; Moussy, Francis; Li, Ya-Li; Zhong, Xiao-Hua

    2010-04-01

    A novel brush-like electrode based on carbon nanotube (CNT) nano-yarn fiber has been designed for electrochemical biosensor applications and its efficacy as an enzymatic glucose biosensor demonstrated. The CNT nano-yarn fiber was spun directly from a chemical-vapor-deposition (CVD) gas flow reaction using a mixture of ethanol and acetone as the carbon source and an iron nano-catalyst. The fiber, 28 µm in diameter, was made of bundles of double walled CNTs (DWNTs) concentrically compacted into multiple layers forming a nano-porous network structure. Cyclic voltammetry study revealed a superior electrocatalytic activity for CNT fiber compared to the traditional Pt-Ir coil electrode. The electrode end tip of the CNT fiber was freeze-fractured to obtain a unique brush-like nano-structure resembling a scale-down electrical 'flex', where glucose oxidase (GOx) enzyme was immobilized using glutaraldehyde crosslinking in the presence of bovine serum albumin (BSA). An outer epoxy-polyurethane (EPU) layer was used as semi-permeable membrane. The sensor function was tested against a standard reference electrode. The sensitivities, linear detection range and linearity for detecting glucose for the miniature CNT fiber electrode were better than that reported for a Pt-Ir coil electrode. Thermal annealing of the CNT fiber at 250 °C for 30 min prior to fabrication of the sensor resulted in a 7.5 fold increase in glucose sensitivity. The as-spun CNT fiber based glucose biosensor was shown to be stable for up to 70 days. In addition, gold coating of the electrode connecting end of the CNT fiber resulted in extending the glucose detection limit to 25 µM. To conclude, superior efficiency of CNT fiber for glucose biosensing was demonstrated compared to a traditional Pt-Ir sensor.

  19. Positronium chemistry in porous adsorbents

    International Nuclear Information System (INIS)

    Foti, G.; Nagy, L.G.; Moravcsik, G.; Schay, G.

    1981-01-01

    Kinetic studies on the annihilation of orthopositronium in porous adsorbents have been performed using lifetime spectroscopy. The positron source applied was 22 Na with 0.2 MBq activity. The adsorbents investigated were silica gels of different particle size and pore structure. The appearance of the long-lived component in the lifetime spectra can be explained by the diffusion of the orthopositronium into the pores affected by the particle size and the pore size of the adsorbent, the coverage on it and the chemical nature of the adsorbate. The long-term aim of the work is to determine and to explain these effects. (author)

  20. Fiber-based hybrid probe for non-invasive cerebral monitoring in neonatology

    Science.gov (United States)

    Rehberger, Matthias; Giovannella, Martina; Pagliazzi, Marco; Weigel, Udo; Durduran, Turgut; Contini, Davide; Spinelli, Lorenzo; Pifferi, Antonio; Torricelli, Alessandro; Schmitt, Robert

    2015-07-01

    Improved cerebral monitoring systems are needed to prevent preterm infants from long-term cognitive and motor restrictions. Combining advanced near-infrared diffuse spectroscopy measurement technologies, time-resolved spectroscopy (TRS) and diffuse correlation spectroscopy (DCS) will introduce novel indicators of cerebral oxygen metabolism and blood flow for neonatology. For non-invasive sensing a fiber-optical probe is used to send and receive light from the infant head. In this study we introduce a new fiber-based hybrid probe that is designed for volume production. The probe supports TRS and DCS measurements in a cross geometry, thus both technologies gain information on the same region inside the tissue. The probe is highly miniaturized to perform cerebral measurements on heads of extreme preterm infants down to head diameters of 6cm. Considerations concerning probe production focus on a reproducible accuracy in shape and precise optical alignment. In this way deviations in measurement data within a series of probes should be minimized. In addition to that, requirements for clinical use like robustness and hygiene are considered. An additional soft-touching sleeve made of FDA compatible silicone allows for a flexible attachment with respect to the individual anatomy of each patient. We present the technical concept of the hybrid probe and corresponding manufacturing methods. A prototype of the probe is shown and tested on tissue phantoms as well as in vivo to verify its operational reliability.

  1. Fiber-Based, Injection-Molded Optofluidic Systems

    DEFF Research Database (Denmark)

    Matteucci, Marco; Triches, Marco; Nava, Giovanni

    2015-01-01

    We present a method to fabricate polymer optofluidic systems by means of injection molding that allow the insertion of standard optical fibers. The chip fabrication and assembly methods produce large numbers of robust optofluidic systems that can be easily assembled and disposed of, yet allow...... out two types of experiments that benefit from the improved optical system: optical stretching of red blood cells (RBCs) and Raman spectroscopy of a solution loaded into a hollow core fiber. The advantages offered by the presented technology are intended to encourage the use of LoC technology...

  2. Cell for studying electron-adsorbed gas interactions; Cellule d'etudes des interactions electron-gaz adsorbe

    Energy Technology Data Exchange (ETDEWEB)

    Golowacz, H; Degras, D A [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires, Deptartement de Physique des Plasmas et de la Fusion Controlee, Service de Physique Appliquee, Service de Physique des Interractions Electroniques, Section d' Etude des Interactions Gaz-Solides

    1967-07-01

    The geometry and the technology of a cell used for investigations on electron-adsorbed gas interactions are described. The resonance frequencies of the surface ions which are created by the electron impact on the adsorbed gas are predicted by simplified calculations. The experimental data relative to carbon monoxide and neon are in good agreement with these predictions. (authors) [French] Les caracteristiques geometriques et technologiques generales d'une cellule d'etude des interactions entre un faisceau d'electrons et un gaz adsorbe sont donnees. Un calcul simplifie permet de prevoir les frequences de resonance des ions de surface crees par l'impact des electrons sur le gaz adsorbe. Les donnees experimentales sur l'oxyde de carbone et le neon confirment les previsions du calcul. (auteurs)

  3. Tunable photonic bandgap fiber based devices for optical networks

    DEFF Research Database (Denmark)

    Alkeskjold, Thomas Tanggaard; Scolari, Lara; Rottwitt, Karsten

    2005-01-01

    In future all optical networks one of the enabling technologies is tunable elements including reconfigurable routers, switches etc. Thus, the development of a technology platform that allows construction of tuning components is critical. Lately, microstructured optical fibers, filled with liquid......, for example a liquid crystal that changes optical properties when subjected to, for example, an optical or an electrical field. The utilization of these two basic properties allows design of tunable optical devices for optical networks. In this work, we focus on applications of such devices and discuss recent...... crystals, have proven to be a candidate for such a platform. Microstructured optical fibers offer unique wave-guiding properties that are strongly related to the design of the air holes in the cladding of the fiber. These wave-guiding properties may be altered by filling the air holes with a material...

  4. Krypton retention on solid adsorbents

    International Nuclear Information System (INIS)

    Monson, P.R. Jr.

    1980-01-01

    Radioactive krypton-85 is released to the atmosphere in the off-gas from nuclear reprocessing plants. Three main methods have been suggested for removal of krypton from off-gas streams: cryogenic distillation; fluorocarbon absorption; and adsorption on solid sorbents. Use of solid adsorbents is the least developed of these methods, but offers the potential advantages of enhanced safety and lower operating costs. An experimental laboratory program was developed that will be used to investigate systematically many solid adsorbents (such as zeolites, i.e., mordenites) for trapping krypton in air. The objective of this investigation is to find an adsorbent that is more economical than silver-exchanged mordenite. Various physical and chemical characteristics such as adsorption isotherms, decontamination factors, co-adsorption, regeneration, and the mechanism and kinetics of noble gas adsorption were used to characterize the adsorbents. In the experimental program, a gas chromatograph using a helium ionization detector was used to measure the krypton in air before and after the adsorbent bed. This method can determine directly decontamination factors greater than 100

  5. Membrane adsorber for endotoxin removal

    Directory of Open Access Journals (Sweden)

    Karina Moita de Almeida

    Full Text Available ABSTRACT The surface of flat-sheet nylon membranes was modified using bisoxirane as the spacer and polyvinyl alcohol as the coating polymer. The amino acid histidine was explored as a ligand for endotoxins, aiming at its application for endotoxin removal from aqueous solutions. Characterization of the membrane adsorber, analysis of the depyrogenation procedures and the evaluation of endotoxin removal efficiency in static mode are discussed. Ligand density of the membranes was around 7 mg/g dry membrane, allowing removal of up to 65% of the endotoxins. The performance of the membrane adsorber prepared using nylon coated with polyvinyl alcohol and containing histidine as the ligand proved superior to other membrane adsorbers reported in the literature. The lack of endotoxin adsorption on nylon membranes without histidine confirmed that endotoxin removal was due to the presence of the ligand at the membrane surface. Modified membranes were highly stable, exhibiting a lifespan of approximately thirty months.

  6. Irradiation Degradation of Adsorbents for Minor Actinides Recovery

    International Nuclear Information System (INIS)

    Watanabe, S.; Sano, Y.; Kofuji, H.; Takeuchi, M.; Koizumi, T.

    2015-01-01

    Extraction chromatography is one of the promising technologies for minor actinides (MA: Am and Cm) recovery from high-level liquid waste. The degradation behaviour of the organic species in the adsorbents under radiation exposure is important to discuss the safety and durability of the adsorbent in the extraction chromatography process. In this study, gamma-ray irradiation experiments on TODGA/SiO 2 -P adsorbent were carried out to investigate the degradation products from radiolysis of the adsorbent. The degraded organic species eluted from the adsorbent and those remaining inside the adsorbent were thoroughly identified by GC/MS, FT-IR and NMR analyses. The species suspected as hydrolysis products of TODGA were mainly detected from the analyses. Since some radicals such as.H or.OH are generated by the gamma-ray irradiation on water molecules, it was discussed that the radicals products from radiolysis of HNO 3 solution are related to the degradation reaction of the extractants. (authors)

  7. Browns Ferry charcoal adsorber incident

    International Nuclear Information System (INIS)

    Mays, G.T.

    1979-01-01

    The article reviews the temperature excursion in the charcoal adsorber beds of the Browns Ferry Unit 3 off-gas system that occurred on July 17, 1977. Significant temperature increases were experienced in the charcoal adsorber beds when charcoal fines were ignited by the ignition of a combustible mixture of hydrogen and oxygen in the off-gas system. The Browns Ferry off-gas system is described, and events leading up to and surrounding the incident are discussed. The follow-up investigation by Tennessee Valley Authority and General Electric Company personnel and their recommendations for system and operational modifications are summarized

  8. Krypton retention on solid adsorbents

    International Nuclear Information System (INIS)

    Monson, P.R. Jr.

    1981-08-01

    Over a dozen prospective adsorbents for krypton were studied and evaluated with respect to adsorption capacity and cost for dissolver off-gas streams from nuclear reprocessing plants. Results show that, at subambient temperature (-40 0 to -80 0 C), the commercially available hydrogen mordenite has sufficient adsorptive capacity to be the most cost-effective material studied. Silver mordenite has a higher capacity for krypton retention, but is 50 times more expensive than hydrogen mordenite. The results indicate that a solid adsorbent system is feasible and competitive with other developing systems whih utilize fluorocarbon absorption and cryogenic distillation

  9. Quantum key distribution over multicore fiber based on silicon photonics

    DEFF Research Database (Denmark)

    Ding, Yunhong; Bacco, Davide; Dalgaard, Kjeld

    on quantum physics. In order to exchange secure information between users, quantum key distribution (QKD), a branch of Quantum Communications (QCs), provides good prospects for ultimate security based on the laws of quantum mechanics [2–7]. Most of QKD systems are implemented in a point-to-point link using...... generations, to HD-entanglement distribution. Furthermore, MCFs are expected as a good candidate for overcoming the capacity limit of a current optical communication system, as example the record capacity of 661 Tbits/s was obtained last year with a 30-cores fiber [8]. Proof of concept experiment has already...... requirements in terms of key generation are needed. A solution may be represented by new technologies applied to quantum world. In particular multicore fiber (MCF) open a new scenario for quantum communications, from high-dimensional (HD) spatial entanglement generation, to HD QKD and multi-user key...

  10. Investigations into Alternative Desorption Agents for Amidoxime-Based Polymeric Uranium Adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Gill, Gary A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kuo, Li-Jung [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Strivens, Jonathan E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wood, Jordana R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wai, Chien [LCW Supercritical Technologies, Inc., Seattle, WA (United States); Pan, Horng-Bin [Univ. of Idaho, Moscow, ID (United States)

    2015-06-01

    Amidoxime-based polymeric braid adsorbents that can extract uranium (U) from seawater are being developed to provide a sustainable supply of fuel for nuclear reactors. A critical step in the development of the technology is to develop elution procedures to selectively remove U from the adsorbents and to do so in a manner that allows the adsorbent material to be reused. This study investigates use of high concentrations of bicarbonate along with targeted chelating agents as an alternative means to the mild acid elution procedures currently in use for selectively eluting uranium from amidoxime-based polymeric adsorbents.

  11. Toward efficient fiber-based quantum interface (Conference Presentation)

    Science.gov (United States)

    Soshenko, Vladimir; Vorobyov, Vadim V.; Bolshedvorsky, Stepan; Lebedev, Nikolay; Akimov, Alexey V.; Sorokin, Vadim; Smolyaninov, Andrey

    2016-04-01

    NV center in diamond is attracting a lot of attention in quantum information processing community [1]. Been spin system in clean and well-controlled environment of diamond it shows outstanding performance as quantum memory even at room temperature, spin control with single shot optical readout and possibility to build up quantum registers even on single NV center. Moreover, NV centers could be used as high-resolution sensitive elements of detectors of magnetic or electric field, temperature, tension, force or rotation. For all of these applications collection of the light emitted by NV center is crucial point. There were number of approaches suggested to address this issue, proposing use of surface plasmoms [2], manufacturing structures in diamond [3] etc. One of the key feature of any practically important interface is compatibility with the fiber technology. Several groups attacking this problem using various approaches. One of them is placing of nanodiamonds in the holes of photonic crystal fiber [4], another is utilization of AFM to pick and place nanodiamond on the tapered fiber[5]. We have developed a novel technique of placing a nanodiamond with single NV center on the tapered fiber by controlled transfer of a nanodiamond from one "donor" tapered fiber to the "target" clean tapered fiber. We verify our ability to transfer only single color centers by means of measurement of second order correlation function. With this technique, we were able to double collection efficiency of confocal microscope. The majority of the factors limiting the collection of photons via optical fiber are technical and may be removed allowing order of magnitude improved in collection. We also discuss number of extensions of this technique to all fiber excitation and integration with nanostructures. References: [1] Marcus W. Doherty, Neil B. Manson, Paul Delaney, Fedor Jelezko, Jörg Wrachtrup, Lloyd C.L. Hollenberg , " The nitrogen-vacancy colour centre in diamond," Physics Reports

  12. Iodine removal adsorbent histories, aging and regeneration

    International Nuclear Information System (INIS)

    Hunt, J.R.; Rankovic, L.; Lubbers, R.; Kovach, J.L.

    1976-01-01

    The experience of efficiency changes with life under various test conditions is described. The adsorbents were periodically removed from both standby and continuously operating systems and tested under various test methods for residual iodine adsorption efficiency. Adsorbent from several conventional ''sampler'' cartridges versus the bulk adsorbent was also tested showing deficiency in the use of cartridge type sampling. Currently required test conditions were found inadequate to follow the aging of the adsorbent because pre-equilibration of the sample acts as a regenerant and the sample is not tested in the ''as is'' condition. The most stringent test was found to be the ambient temperature, high humidity test to follow the aging of the adsorbent. Several methods were evaluated to regenerate used adsorbents; of these high temperature steaming and partial reimpregnation were found to produce adsorbents with near identical properties of freshly prepared adsorbents

  13. Supercritical fluid regeneration of adsorbents

    Science.gov (United States)

    Defilippi, R. P.; Robey, R. J.

    1983-05-01

    The results of a program to perform studies supercritical (fluid) carbon dioxide (SCF CO2) regeneration of adsorbents, using samples of industrial wastewaters from manufacturing pesticides and synthetic solution, and to estimate the economics of the specific wastewater treatment regenerations, based on test data are given. Processing costs for regenerating granular activated carbon GAC) for treating industrial wastewaters depend on stream properties and regeneration throughput.

  14. Analysis of Scaling Law and Figure of Merit of Fiber-Based Biosensor

    Directory of Open Access Journals (Sweden)

    Jui-Teng Lin

    2012-01-01

    Full Text Available This paper presents a normalized transmitted signal (NTS of a fiber-based sensor using gold nanorods as the plasmon excitation medium of the evanescent wave. The NTS and the refractive index (RI sensitivity is calculated as a function of the gold aspect ratio (R, the RI of the sensing medium, and a scaling parameter given by the ratio of the fiber length and its diameter. Finally, the optimal value of gold aspect ratio is calculated to be R = (3.0–4.0 for maximum figure of merits (FOMs defined by the ratio of the refractive index sensitivity and the full width at half maximum. The scaling laws and the FOM presented in this paper may serve as the guidelines for optimal designs in fiber-based nanosensors.

  15. Thermo-tunable hybrid photonic crystal fiber based on solution-processed chalcogenide glass nanolayers

    DEFF Research Database (Denmark)

    Markos, Christos

    2016-01-01

    the air-capillaries of the fiber based on a solution-processed glass approach. The deposited high-index layers revealed antiresonant transmission windows from similar to 500 nm up to similar to 1300 nm. We experimentally demonstrate for the first time the possibility to thermally-tune the revealed....../degrees C at 1300 nm. The proposed fiber device could potentially constitute an efficient route towards realization of monolithic tunable fiber filters or sensing elements....

  16. An image fiber based fluorescent probe with associated signal processing scheme for biomedical diagnostics

    International Nuclear Information System (INIS)

    Vaishakh, M; Murukeshan, V M; Seah, L K

    2008-01-01

    A dual-modality image fiber based fluorescent probe that can be used for depth sensitive imaging and suppression of fluorescent emissions with nanosecond lifetime difference is proposed and illustrated in this paper. The system can give high optical sectioning and employs an algorithm for obtaining phase sensitive images. The system can find main application in in vivo biomedical diagnostics for detecting biochemical changes for distinguishing malignant tissue from healthy tissue

  17. Fatigue behavior of wood-fiber-based tri-axial engineered sandwich composite panels (ESCP)

    Science.gov (United States)

    Jinghao Li; John F. Hunt; Shaoqin Gong; Zhiyong Cai

    2015-01-01

    The static and fatigue bending behavior of wood-fiber-based tri-axial engineered sandwich composite panels (ESCP) has been investigated by four-point bending tests. Fatigue panels and weakened panels (wESCP) with an initial interface defect were manufactured for the fatigue tests. Stress σ vs. number of cycles curves (S-N) were recorded under the different stress...

  18. Single Mode Optical Fiber based Refractive Index Sensor using Etched Cladding

    OpenAIRE

    Kumar, Ajay; Gupta, Geeta; Mallik, Arun; Bhatnagar, Anuj

    2011-01-01

    The use of optical fiber for sensor applications is a topic of current interest. We report the fabrication of etched single mode optical fiber based refractive index sensor. Experiments are performed to determine the etch rate of fiber in buffered hydrofluoric acid, which can be high or low depending upon the temperature at which etching is carried out. Controlled wet etching of fiber cladding is performed using these measurements and etched fiber region is tested for refractive index sensing...

  19. Arsenic Remediation by Synthetic and Natural Adsorbents

    Directory of Open Access Journals (Sweden)

    Muhammad Saqaf Jagirani

    2017-06-01

    Full Text Available The contagion of toxic metals in water is a serious environmental and health concern and threatening problem worldwide. Particularly arsenic contamination in ground water has became great dilemma in the earlier decades. With advent in research for arsenic remediation, standard of drinking water is improving and now reduced to few parts per million (ppm level of arsenic in drinking water sources. However, due to continuous enhancement in environmental pollution, remediation techniques are still needed to achieve the drinking water quality standard. Development of novel and economically feasible removal techniques or materials for selective separation of this toxic specie has been the main focus of research. Several arsenic removal techniques, including membrane separation, coagulation, precipitation, anion exchange have been developed. The aim of this article is to review briefly arsenic chemistry and previous and current available technologies that have been reported various low-cost adsorbents for arsenic removal.

  20. Thermal enhancement of charge and discharge cycles for adsorbed natural gas storage

    KAUST Repository

    Rahman, Kazi Afzalur; Loh, Wai Soong; Chakraborty, Anutosh; Saha, Bidyut Baran; Chun, Won Gee; Ng, Kim Choon

    2011-01-01

    The usage of adsorbed natural gas (ANG) storage is hindered by the thermal management during the adsorption and desorption processes. An effective thermal enhancement is thus essential for the development of the ANG technology and the motivation

  1. Removal of arsenic from water using nano adsorbents and challenges: A review.

    Science.gov (United States)

    Lata, Sneh; Samadder, S R

    2016-01-15

    Many researchers have used nanoparticles as adsorbents to remove water pollutants including arsenic after modifying the properties of nanoparticles by improving reactivity, biocompatibility, stability, charge density, multi-functionalities, and dispersibility. For arsenic removal, nano adsorbents emerged as the potential alternatives to existing conventional technologies. The present study critically reviewed the past and current available information on the potential of nano adsorbents for arsenic removal from contaminated water and the challenges involved in that. The study discussed the separation and regeneration techniques of nano adsorbents and the performance thereof. The study evaluated the adsorption efficiency of the various nanoparticles based on size of nanoparticles, types of nano adsorbents, method of synthesis, separation and regeneration of the nano adsorbents. The study found that more studies are required on suitable holding materials for the nano adsorbents to improve the permeability and to make the technology applicable at the field condition. The study will help the readers to choose suitable nanomaterials and to take up further research required for arsenic removal using nano adsorbents. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Fiber Based Optical Amplifier for High Energy Laser Pulses Final Report CRADA No. TC02100.0

    Energy Technology Data Exchange (ETDEWEB)

    Messerly, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Cunningham, P. [Boeing Company, Springfield, VA (United States)

    2017-09-06

    This was a collaborative effort between Lawrence Livermore National Security, LLC (formerly The Regents of the University of California)/Lawrence Livermore National Laboratory (LLNL), and The Boeing Company to develop an optical fiber-based laser amplifier capable of producing and sustaining very high-energy, nanosecond-scale optical pulses. The overall technical objective of this CRADA was to research, design, and develop an optical fiber-based amplifier that would meet specific metrics.

  3. Influence of the precursor chemical composition on heavy metal adsorption properties of hemp (Cannabis Sativa fibers based biocarbon

    Directory of Open Access Journals (Sweden)

    Vukčević Marija M.

    2017-01-01

    Full Text Available Waste hemp (Cannabis sativa fibers were used as sustainable and renewable raw materials for production of low-cost biocarbon sorbent for heavy metals removal. Carbon precursors of different chemical composition were obtained by oxidative and alkaline treatments of hemp fibers. Influence of lignocellulosic precursor chemical composition on hemp fibers-based biocarbon (HFB characteristics was examined by BET surface area measurement, scanning electron microscopy and mass titration. It was found that lignin content and polymorphic transformation of cellulose increase the SBET of microporous HFBs, while hemicelluloses induce more homogeneous distribution of adsorption active sites. Heavy metal ions adsorption onto HFBs is primarily influenced by the amount of surface oxygen groups, while specific surface area plays a secondary role. Equilibrium data obtained for lead ions adsorption were analyzed by different nonlinear adsorption isotherms, and the best fitting model was chosen using standard deviation and Akaike information criterion (AICC. The maximum adsorption capacities of HFBs ranged from 103.1 to 116.3 mg Pb/g. Thermodynamic parameters showed that Pb2+ adsorption onto HFBs is a spontaneous and complex endothermic process, suggesting the coexistence of physisorption and chemisorption mechanisms. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172007 and Grant no. 172029

  4. Microstructured Optical Fiber-based Biosensors: Reversible and Nanoliter-Scale Measurement of Zinc Ions.

    Science.gov (United States)

    Heng, Sabrina; McDevitt, Christopher A; Kostecki, Roman; Morey, Jacqueline R; Eijkelkamp, Bart A; Ebendorff-Heidepriem, Heike; Monro, Tanya M; Abell, Andrew D

    2016-05-25

    Sensing platforms that allow rapid and efficient detection of metal ions would have applications in disease diagnosis and study, as well as environmental sensing. Here, we report the first microstructured optical fiber-based biosensor for the reversible and nanoliter-scale measurement of metal ions. Specifically, a photoswitchable spiropyran Zn(2+) sensor is incorporated within the microenvironment of a liposome attached to microstructured optical fibers (exposed-core and suspended-core microstructured optical fibers). Both fiber-based platforms retains high selectivity of ion binding associated with a small molecule sensor, while also allowing nanoliter volume sampling and on/off switching. We have demonstrated that multiple measurements can be made on a single sample without the need to change the sensor. The ability of the new sensing platform to sense Zn(2+) in pleural lavage and nasopharynx of mice was compared to that of established ion sensing methodologies such as inductively coupled plasma mass spectrometry (ICP-MS) and a commercially available fluorophore (Fluozin-3), where the optical-fiber-based sensor provides a significant advantage in that it allows the use of nanoliter (nL) sampling when compared to ICP-MS (mL) and FluoZin-3 (μL). This work paves the way to a generic approach for developing surface-based ion sensors using a range of sensor molecules, which can be attached to a surface without the need for its chemical modification and presents an opportunity for the development of new and highly specific ion sensors for real time sensing applications.

  5. White matter fiber-based analysis of T1w/T2w ratio map

    Science.gov (United States)

    Chen, Haiwei; Budin, Francois; Noel, Jean; Prieto, Juan Carlos; Gilmore, John; Rasmussen, Jerod; Wadhwa, Pathik D.; Entringer, Sonja; Buss, Claudia; Styner, Martin

    2017-02-01

    Purpose: To develop, test, evaluate and apply a novel tool for the white matter fiber-based analysis of T1w/T2w ratio maps quantifying myelin content. Background: The cerebral white matter in the human brain develops from a mostly non-myelinated state to a nearly fully mature white matter myelination within the first few years of life. High resolution T1w/T2w ratio maps are believed to be effective in quantitatively estimating myelin content on a voxel-wise basis. We propose the use of a fiber-tract-based analysis of such T1w/T2w ratio data, as it allows us to separate fiber bundles that a common regional analysis imprecisely groups together, and to associate effects to specific tracts rather than large, broad regions. Methods: We developed an intuitive, open source tool to facilitate such fiber-based studies of T1w/T2w ratio maps. Via its Graphical User Interface (GUI) the tool is accessible to non-technical users. The framework uses calibrated T1w/T2w ratio maps and a prior fiber atlas as an input to generate profiles of T1w/T2w values. The resulting fiber profiles are used in a statistical analysis that performs along-tract functional statistical analysis. We applied this approach to a preliminary study of early brain development in neonates. Results: We developed an open-source tool for the fiber based analysis of T1w/T2w ratio maps and tested it in a study of brain development.

  6. White Matter Fiber-based Analysis of T1w/T2w Ratio Map.

    Science.gov (United States)

    Chen, Haiwei; Budin, Francois; Noel, Jean; Prieto, Juan Carlos; Gilmore, John; Rasmussen, Jerod; Wadhwa, Pathik D; Entringer, Sonja; Buss, Claudia; Styner, Martin

    2017-02-01

    To develop, test, evaluate and apply a novel tool for the white matter fiber-based analysis of T1w/T2w ratio maps quantifying myelin content. The cerebral white matter in the human brain develops from a mostly non-myelinated state to a nearly fully mature white matter myelination within the first few years of life. High resolution T1w/T2w ratio maps are believed to be effective in quantitatively estimating myelin content on a voxel-wise basis. We propose the use of a fiber-tract-based analysis of such T1w/T2w ratio data, as it allows us to separate fiber bundles that a common regional analysis imprecisely groups together, and to associate effects to specific tracts rather than large, broad regions. We developed an intuitive, open source tool to facilitate such fiber-based studies of T1w/T2w ratio maps. Via its Graphical User Interface (GUI) the tool is accessible to non-technical users. The framework uses calibrated T1w/T2w ratio maps and a prior fiber atlas as an input to generate profiles of T1w/T2w values. The resulting fiber profiles are used in a statistical analysis that performs along-tract functional statistical analysis. We applied this approach to a preliminary study of early brain development in neonates. We developed an open-source tool for the fiber based analysis of T1w/T2w ratio maps and tested it in a study of brain development.

  7. Optical fiber-based core-shell coaxially structured hybrid cells for self-powered nanosystems

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Caofeng; Zhu, Guang [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia (United States); Guo, Wenxi [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia (United States); State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Dong, Lin [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia (United States); School of Materials Science and Enginnering, Zhenzhou University, Zhenghou 450001 (China); Wang, Zhong Lin [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia (United States); Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing (China)

    2012-07-03

    An optical fiber-based 3D hybrid cell consisting of a coaxially structured dye-sensitized solar cell (DSSC) and a nanogenerator (NG) for simultaneously or independently harvesting solar and mechanical energy is demonstrated. The current output of the hybrid cell is dominated by the DSSC, and the voltage output is dominated by the NG; these can be utilized complementarily for different applications. The output of the hybrid cell is about 7.65 {mu}A current and 3.3 V voltage, which is strong enough to power nanodevices and even commercial electronic components. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Neutron scattering from adsorbed species

    International Nuclear Information System (INIS)

    Shuwang An

    1998-01-01

    Neutron reflection has been used to investigate the structure of layers of water-soluble diblock copolymers poly(2-(dimethylamino)ethyl methacrylate-block-methyl methacrylate (poly(DMAEMA-b-MMA)) (70 mol% DMAEMA, M n = 10k, 80 mol% DMAEMA, M n = 10k, and 70 mol% DMAEMA, M n = 20k) adsorbed at the air-liquid and solid-liquid interfaces. The surface tension behaviour of these copolymers at the air-liquid interface has also been investigated. The study of the structure of layers of poly(DMAEMA-b-MMA) adsorbed at the air-water interface forms the main part of the thesis. The surface structure, the effects of pH and ionic strength, and the effects of composition and molecular weight of the copolymers have been studied systematically. For the 70%-10k copolymer at pH 7.5, the adsorption isotherm shows that there is a surface phase transition. The concentration of copolymer at which the phase transition occurs is close to that at which micellar aggregation in the bulk solution also occurs. At low concentrations (below the CMC), the two blocks of the copolymer are approximately uniformly distributed in the direction normal to the interface and the layer is partially immersed in water. At high concentrations (above the CMC), the adsorbed layer has a cross-sectional structure resembling that expected for a micelle with the majority of the MMA blocks forming the core. The outer layers, comprising predominantly DMAEMA blocks, are not equivalent, being more highly extended on the aqueous side of the interface. The effects of pH and added electrolyte on the structure of layers of the 70%-10k copolymer show that the layered structure is promoted by any changes in the bulk solution that enhance the surface coverage but is inhibited by an increase in the fractional charge on the polyelectrolyte part of the copolymer. The effect of lowering the pH is to increase the positive charge on the weak polyelectrolyte block. Addition of electrolyte generally enhances the amount adsorbed and

  9. Filter-adsorber aging assessment

    Energy Technology Data Exchange (ETDEWEB)

    Winegardner, W.K. [Pacific Northwest Laboratory, Richland, WA (United States)

    1995-02-01

    An aging assessment of high-efficiency particulate (HEPA) air filters and activated carbon gas adsorption units was performed by the Pacific Northwest Laboratory as part of the U.S. Nuclear Regulatory Commission`s (USNRC) Nuclear Plant Aging Research (NPAR) Program. This evaluation of the general process in which characteristics of these two components gradually change with time or use included the compilation of information concerning failure experience, stressors, aging mechanisms and effects, and inspection, surveillance, and monitoring methods (ISMM). Stressors, the agents or stimuli that can produce aging degradation, include heat, radiation, volatile contaminants, and even normal concentrations of aerosol particles and gasses. In an experimental evaluation of degradation in terms of the tensile breaking strength of aged filter media specimens, over forty percent of the samples did not meet specifications for new material. Chemical and physical reactions can gradually embrittle sealants and gaskets as well as filter media. Mechanisms that can lead to impaired adsorber performance are associated with the loss of potentially available active sites as a result of the exposure of the carbon to airborne moisture or volatile organic compounds. Inspection, surveillance, and monitoring methods have been established to observe filter pressure drop buildup, check HEPA filters and adsorbers for bypass, and determine the retention effectiveness of aged carbon. These evaluations of installed filters do not reveal degradation in terms of reduced media strength but that under normal conditions aged media can continue to effectively retain particles. However, this degradation may be important when considering the likelihood of moisture, steam, and higher particle loadings during severe accidents and the fact it is probable that the filters have been in use for an extended period.

  10. Ecological applications of the irradiated adsorbents

    International Nuclear Information System (INIS)

    Tusseyev, T.

    2004-01-01

    Full text: In our previous works it was shown that after irradiation some adsorbents gain new interesting properties such as increasing (or decreasing) of their adsorption capacity, selectivity in relation to some gases, change of chemical bounds of gas molecules with adsorbent surface as well as other properties. We investigated a lot of adsorbents with semiconducting and dielectric properties. A high temperature superconductor was investigated also. Adsorbents were irradiated by ultraviolet (UV) and gamma - radiation, reactor (n.γ) - radiation, α-particles (E=40-50 MeV), protons ( E=30 MeV), and also He-3 ions (E-29-60 MeV). The following techniques were used: volumetric (manometrical), mass-spectrometer and IR spectroscopic methods, and also method of electronic - paramagnetic resonance (spin paramagnetic resonance) The obtained results allow to speak about creation of new adsorbents for gas purification (clearing) from harmful impurities, gas selection into components, an increasing of adsorbing surface. Thus one more advantage of the irradiated adsorbents is that they have 'memory effect', i.e. they can be used enough long time after irradiation. In laboratory conditions we built the small-sized adsorptive pump on the basis of the irradiated zeolites which are capable to work in autonomous conditions. It was found, that some of adsorbents after irradiation gain (or lose) selectivity in relation to definite gases. So, silica gel, which one in initial state does not adsorb hydrogen, after gamma irradiation it becomes active in relation to hydrogen. Some of rare earths oxides also show selectivity in relation to hydrogen and oxygen depending on a type of irradiation. Thus, it is possible to create different absorbents, depending on a solved problem, using a way or selection of adsorbents, either of radiation type and energy, as a result obtained adsorbents can be used for various ecological purposes

  11. Complete braided adsorbent for marine testing to demonstrate 3g-U/kg-adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Janke, Chris [ORNL; Yatsandra, Oyola [ORNL; Mayes, Richard [ORNL; none,; Gill, Gary [PNNL; Li-Jung, Kuo [PNNL; Wood, Jordana [PNNL; Sadananda, Das [ORNL

    2014-04-30

    ORNL has manufactured four braided adsorbents that successfully demonstrated uranium adsorption capacities ranging from 3.0-3.6 g-U/kg-adsorbent in marine testing at PNNL. Four new braided and leno woven fabric adsorbents have also been prepared by ORNL and are currently undergoing marine testing at PNNL.

  12. Enhancing Electrochemical Performance of Graphene Fiber-Based Supercapacitors by Plasma Treatment.

    Science.gov (United States)

    Meng, Jie; Nie, Wenqi; Zhang, Kun; Xu, Fujun; Ding, Xin; Wang, Shiren; Qiu, Yiping

    2018-04-25

    Graphene fiber-based supercapacitors (GFSCs) hold high power density, fast charge-discharge rate, ultralong cycling life, exceptional mechanical/electrical properties, and safe operation conditions, making them very promising to power small wearable electronics. However, the electrochemical performance is still limited by the severe stacking of graphene sheets, hydrophobicity of graphene fibers, and complex preparation process. In this work, we develop a facile but robust strategy to easily enhance electrochemical properties of all-solid-state GFSCs by simple plasma treatment. We find that 1 min plasma treatment under an ambient condition results in 33.1% enhancement of areal specific capacitance (36.25 mF/cm 2 ) in comparison to the as-prepared GFSC. The energy density reaches 0.80 μW h/cm 2 in polyvinyl alcohol/H 2 SO 4 gel electrolyte and 18.12 μW h/cm 2 in poly(vinylidene difluoride)/ethyl-3-methylimidazolium tetrafluoroborate electrolyte, which are 22 times of that of as-prepared ones. The plasma-treated GFSCs also exhibit ultrahigh rate capability (69.13% for 40 s plasma-treated ones) and superior cycle stability (96.14% capacitance retention after 20 000 cycles for 1 min plasma-treated ones). This plasma strategy can be extended to mass-manufacture high-performance carbonaceous fiber-based supercapacitors, such as graphene and carbon nanotube-based ones.

  13. Fiber-based modulated optical reflectance configuration allowing for offset pump and probe beams

    Science.gov (United States)

    Fleming, A.; Folsom, C.; Jensen, C.; Ban, H.

    2016-12-01

    A new fiber-based modulated optical reflectance configuration is developed in this work. The technique maintains the fiber-based heating laser (pump) and detection laser (probe) in close proximity at a fixed separation distance in a ceramic ferrule. The pump beam periodically heats the sample inducing thermal waves into the sample. The probe beam measures the temperature response at a known distance from the pump beam over a range of heating modulation frequencies. The thermal diffusivity of the sample may be calculated from the phase response between the input heat flux and the temperature response of a sample having a reflective surface. The unique measurement configuration is ideal for in situ measurements and has many advantages for laboratory-based systems. The design and development of the system are reported along with theoretical justification for the experimental design. The thermal diffusivities of Ge and SiC are measured and found to be within 10% of reported literature values. The diffusivity for SiO2 is measured with a relative difference of approximately 100% from the literature value when the ferrule is in contact with the sample. An additional measurement was made on the SiO2 sample with the ferrule not in contact resulting in a difference of less than 2% from the literature value. The difference in the SiO2 measurement when the ferrule is in contact with the sample is likely due to a parallel heat transfer path through the dual-fiber ferrule assembly.

  14. Thermodynamics of gas adsorption on solid adsorbents

    International Nuclear Information System (INIS)

    Budrugeac, P.

    1979-01-01

    Starting with several hypotheses about the adsorbtion system and the adsorption phenomenon, a thermodynamic treatment of gas adsorption on solid adsorbants is presented. The relationships for determination from isotherms and calorimetric data of thermodynamic functions are derived. The problem of the phase changes in adsorbed layer is discussed. (author)

  15. Analysis of Adsorbate-Adsorbate and Adsorbate-Adsorbent Interactions to Decode Isosteric Heats of Gas Adsorption.

    Science.gov (United States)

    Madani, S Hadi; Sedghi, Saeid; Biggs, Mark J; Pendleton, Phillip

    2015-12-21

    A qualitative interpretation is proposed to interpret isosteric heats of adsorption by considering contributions from three general classes of interaction energy: fluid-fluid heat, fluid-solid heat, and fluid-high-energy site (HES) heat. Multiple temperature adsorption isotherms are defined for nitrogen, T=(75, 77, 79) K, argon at T=(85, 87, 89) K, and for water and methanol at T=(278, 288, 298) K on a well-characterized polymer-based, activated carbon. Nitrogen and argon are subjected to isosteric heat analyses; their zero filling isosteric heats of adsorption are consistent with slit-pore, adsorption energy enhancement modelling. Water adsorbs entirely via specific interactions, offering decreasing isosteric heat at low pore filling followed by a constant heat slightly in excess of water condensation enthalpy, demonstrating the effects of micropores. Methanol offers both specific adsorption via the alcohol group and non-specific interactions via its methyl group; the isosteric heat increases at low pore filling, indicating the predominance of non-specific interactions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Development of an Optical Fiber-Based MR Compatible Gamma Camera for SPECT/MRI Systems

    Science.gov (United States)

    Yamamoto, Seiichi; Watabe, Tadashi; Kanai, Yasukazu; Watabe, Hiroshi; Hatazawa, Jun

    2015-02-01

    Optical fiber is a promising material for integrated positron emission tomography (PET) and magnetic resonance imaging (MRI) PET/MRI systems. Because its material is plastic, it has no interference between MRI. However, it is unclear whether this material can also be used for a single photon emission tomography (SPECT)/MRI system. For this purpose, we developed an optical fiber-based block detector for a SPECT/MRI system and tested its performance by combining 1.2 ×1.2 ×6 mm Y2SiO5 (YSO) pixels into a 15 ×15 block and was coupled it to an optical fiber image guide that used was 0.5-mm in diameter with 80-cm long double clad fibers. The image guide had 22 ×22 mm rectangular input and an equal size output. The input of the optical fiber-based image guide was bent at 90 degrees, and the output was optically coupled to a 1-in square high quantum efficiency position sensitive photomultiplier tube (HQE-PSPMT). The parallel hole, 7-mm-thick collimator made of tungsten plastic was mounted on a YSO block. The diameter of the collimator holes was 0.8 mm which was positioned one-to-one coupled to the YSO pixels. We evaluated the intrinsic and system performances. We resolved most of the YSO pixels in a two-dimensional histogram for Co-57 gamma photons (122-keV) with an average peak-to-value ratio of 1.5. The energy resolution was 38% full-width at half-maximum (FWHM). The system resolution was 1.7-mm FWHM, 1.5 mm from the collimator surface, and the sensitivity was 0.06%. Images of a Co-57 point source could be successfully obtained inside 0.3 T MRI without serious interference. We conclude that the developed optical fiber-based YSO block detector is promising for SPECT/MRI systems.

  17. Objective-lens-free Fiber-based Position Detection with Nanometer Resolution in a Fiber Optical Trapping System.

    Science.gov (United States)

    Ti, Chaoyang; Ho-Thanh, Minh-Tri; Wen, Qi; Liu, Yuxiang

    2017-10-13

    Position detection with high accuracy is crucial for force calibration of optical trapping systems. Most existing position detection methods require high-numerical-aperture objective lenses, which are bulky, expensive, and difficult to miniaturize. Here, we report an affordable objective-lens-free, fiber-based position detection scheme with 2 nm spatial resolution and 150 MHz bandwidth. This fiber based detection mechanism enables simultaneous trapping and force measurements in a compact fiber optical tweezers system. In addition, we achieved more reliable signal acquisition with less distortion compared with objective based position detection methods, thanks to the light guiding in optical fibers and small distance between the fiber tips and trapped particle. As a demonstration of the fiber based detection, we used the fiber optical tweezers to apply a force on a cell membrane and simultaneously measure the cellular response.

  18. Interplay of adsorbate-adsorbate and adsorbate-substrate interactions in self-assembled molecular surface nanostructures

    DEFF Research Database (Denmark)

    Schnadt, Joachim; Xu, Wei; Vang, Ronnie Thorbjørn

    2010-01-01

    a large tolerance to monatomic surface steps on the Ag(110) surface. The observed behaviour is explained in terms of strong intermolecular hydrogen bonding and a strong surface-mediated directionality, assisted by a sufficient degree of molecular backbone flexibility. In contrast, the same kind of step......-edge crossing is not observed when the molecules are adsorbed on the isotropic Ag(111) or more reactive Cu(110) surfaces. On Ag(111), similar 1-D assemblies are formed to those on Ag(110), but they are oriented along the step edges. On Cu(110), the carboxylic groups of NDCA are deprotonated and form covalent...... bonds to the surface, a situation which is also achieved on Ag(110) by annealing to 200 degrees C. These results show that the formation of particular self-assembled molecular nanostructures depends significantly on a subtle balance between the adsorbate-adsorbate and adsorbate-substrate interactions...

  19. Fiber-Based Polarization Diversity Detection for Polarization-Sensitive Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Hamid Pahlevaninezhad

    2014-09-01

    Full Text Available We present a new fiber-based polarization diversity detection (PDD scheme for polarization sensitive optical coherence tomography (PSOCT. This implementation uses a new custom miniaturized polarization-maintaining fiber coupler with single mode (SM fiber inputs and polarization maintaining (PM fiber outputs. The SM fiber inputs obviate matching the optical lengths of the two orthogonal OCT polarization channels prior to interference while the PM fiber outputs ensure defined orthogonal axes after interference. Advantages of this detection scheme over those with bulk optics PDD include lower cost, easier miniaturization, and more relaxed alignment and handling issues. We incorporate this PDD scheme into a galvanometer-scanned OCT system to demonstrate system calibration and PSOCT imaging of an achromatic quarter-wave plate, fingernail in vivo, and chicken breast, salmon, cow leg, and basa fish muscle samples ex vivo.

  20. Fiber-based optic sensor for detecting human blood clot: present and future revival

    Science.gov (United States)

    Elshikeri, Nada; Bakhtiar, Hazri

    2018-05-01

    Sustaining human’s life-frame away from being impeded by the clot - ghost term, we attempt to approach a mobile fiber-based optical sensor (f-s) for detecting blood clot in a blood vessel (intra-arteries/veins). Blood vessels are the part of the circulatory system that transport blood throughout the human body, thus their significance of being protected arise to the monograph focus. MRI (magnetic resonance imaging), X-rays and other medical instruments are diagnostic immobility techniques with a slackest interval. The corer causation of fiber-based optical sensor is to detect a clump of blood in the bloodstream by providing a prompt mobile diagnostic intervals preserving last-minutes-breath of human’s life. The detector (f-s) has been etched by diluting sulphuric acid ~10% at certain zone to sensate its function. The in-vitro monograph peaks its maximal monitoring when the sensor is attached to Raman Spectroscopy (RS) setup. RS quantifies the relative intensities of fibrinogen bond, which is the first type of blood coagulation elements of blood plasma. Blood coagulation parameters are the major concern of the monograph investigation, such as total haemoglobin (tHb), clotting reaction time (t), clot progression time (t2), maximum clot amplitude (ma) and mean refractive index (r). A blood sample will be drawn from the patient and after centrifugation to separate blood plasma from its constituents, then an immediate sloshing of blood plasma in the (f-s) packet which has its plug-in to RS. Estimating the quantitative analysis of blood sample concentration, RS will determine the presence of coagulation in terms of intensity and medical procedures will dominate the treatment process. Thus, the suggestive monograph provides a definite instrument for investigating blood coagulation intra-arteries/veins promptly.

  1. Alkali metal adsorbate sputtering by molecular impact

    International Nuclear Information System (INIS)

    Moran, J.P.; Wachman, H.Y.; Trilling, L.

    1974-01-01

    An exploratory study of the sputtering by a krypton molecular beam of rubidium adsorbed at low coverage on a tungsten substrate has been described in a previous paper. An extension of this work is reported now

  2. PERVAPORATION USING ADSORBENT-FILLED MEMBRANES

    Science.gov (United States)

    Membranes containing selective fillers, such as zeolites and activated carbon, can improve the separation by pervaporation. Applications of adsorbent-filled membranes in pervaporation have been demonstrated by a number of studies. These applications include removal of organic co...

  3. Chitin Adsorbents for Toxic Metals: A Review

    Directory of Open Access Journals (Sweden)

    Ioannis Anastopoulos

    2017-01-01

    Full Text Available Wastewater treatment is still a critical issue all over the world. Among examined methods for the decontamination of wastewaters, adsorption is a promising, cheap, environmentally friendly and efficient procedure. There are various types of adsorbents that have been used to remove different pollutants such as agricultural waste, compost, nanomaterials, algae, etc., Chitin (poly-β-(1,4-N-acetyl-d-glucosamine is the second most abundant natural biopolymer and it has attracted scientific attention as an inexpensive adsorbent for toxic metals. This review article provides information about the use of chitin as an adsorbent. A list of chitin adsorbents with maximum adsorption capacity and the best isotherm and kinetic fitting models are provided. Moreover, thermodynamic studies, regeneration studies, the mechanism of adsorption and the experimental conditions are also discussed in depth.

  4. Methyl iodide tests on used adsorbents

    International Nuclear Information System (INIS)

    Kovach, J.L.

    1993-01-01

    This paper discusses the history of events leading to the current problems in radioiodine test conditions. These radioiodine tests are performed in the adsorbent media from both safety and non-safety related Nuclear Air Treatment Systems (NATS). The main problem addressed is that currently there are still numerous plant technical specifications for NATS which reference outdated test protocols for the surveillance testing of the radioactive methyl iodide performance of the adsorbents. Recommendations for correcting the test condition problems are presented. 7 refs

  5. Dissolved Air Flotation of arsenic adsorbent particles

    Directory of Open Access Journals (Sweden)

    Mario Enrique Santander Muñoz

    2015-01-01

    Full Text Available The removal of arsenic from synthetic effluent was studied using the adsorbent particle flotation technique (APF and dissolved air flotation (DAF. A sample of an iron mineral was used as adsorbent particles of arsenic, ferric chloride as coagulant, cationic poly-acrylamide (NALCO 9808 as flocculants, and sodium oleate as collector. Adsorption studies to determine the pH influence, contact time, and adsorbent particles concentration on the adsorption of arsenic were carried out along with flotation studies to determine the removal efficiency of adsorbents particles. The results achieved indicate that the adsorption kinetic of arsenic is very rapid and that in range of pH’s from 2 to 7 the adsorption percentages remain constant. The equilibrium conditions were achieved in 60 minutes and about 95% of arsenic was adsorbed when used an adsorbent concentration of 2 g/L and pH 6.3. The maximum adsorption capacity of adsorbent particles was 4.96 mg/g. The mean free energy of adsorption (E was found to be 2.63 kJ/mol, which suggests physisorption. The results of the flotation studies demonstrated that when synthetic effluents with 8.9 mg/L of arsenic were treated under the following experimental conditions; 2 g/L of adsorbent particles, 120 mg/L of Fe(III, 2 mg/L of Nalco 9808, 20 mg/L of sodium oleate, and 40% of recycle ratio in the DAF, it was possible to reach 98% of arsenic removal and 6.3 NTU of residual turbidity in clarified synthetic effluent.

  6. Properties and selection criteria for adsorbents

    International Nuclear Information System (INIS)

    Wirth, H.

    1976-01-01

    The paper gives a survey of the most important industrial adsorbents and of their suitability for different purposes. With special consideration of activated carbon, the properties and characteristic data are discussed which are used for assessing adsorbents. These, among other things, are as follows: specific surface area, pore size distribution, adsorption isotherms, hydrophobic properties, catalytic properties, chemical resistance, heat resistance, particle size and hardness. (orig.) [de

  7. Protein purification using magnetic adsorbent particles

    DEFF Research Database (Denmark)

    Franzreb, M; Siemann-Herzberg, M.; Hobley, Timothy John

    2006-01-01

    The application of functionalised magnetic adsorbent particles in combination with magnetic separation techniques has received considerable attention in recent years. The magnetically responsive nature of such adsorbent particles permits their selective manipulation and separation in the presence...... separations are fast, gentle, scaleable, easily automated, can achieve separations that would be impossible or impractical to achieve by other techniques, and have demonstrated credibility in a wide range of disciplines, including minerals processing, wastewater treatment, molecular biology, cell sorting...

  8. Mesoporous Silica: A Suitable Adsorbent for Amines

    Directory of Open Access Journals (Sweden)

    Abdollahzadeh-Ghom Sara

    2009-01-01

    Full Text Available Abstract Mesoporous silica with KIT-6 structure was investigated as a preconcentrating material in chromatographic systems for ammonia and trimethylamine. Its adsorption capacity was compared to that of existing commercial materials, showing its increased adsorption power. In addition, KIT-6 mesoporous silica efficiently adsorbs both gases, while none of the employed commercial adsorbents did. This means that KIT-6 Mesoporous silica may be a good choice for integrated chromatography/gas sensing micro-devices.

  9. Effect of γ-ray irradiation on adsorbents used in organic waste treatment

    International Nuclear Information System (INIS)

    Unsworth, T.J.; Krishma, R.; Pimblott, S.M.

    2015-01-01

    Radioactive organic liquids (ROLs) are waste that require specific treatment. The Arvia process, developed by Arvia Technology Ltd., combines adsorption of organic material with electrochemical oxidation. This work focuses on the effect of γ-rays on the performance of adsorbents used in the Arvia process. Adsorbents used in this experimental study were provided by Arvia Technology Ltd. Specifically, Nyex 1000, a flake like carbon-based adsorbent, and Nyex 2105, a carbon-based adsorbent with a granular morphology. The γ-ray irradiation experiments were carried out using a Co-60 irradiator. The impact of irradiation on the microstructure, the adsorption capacity and the leaching of the 2 adsorbents were studied. The results show that no significant changes were detected in terms of structure, adsorption capacity and leaching of ions. The results of this paper are promising for the use of Nyex 1000 and Nyex 2105 as adsorbents in electrochemical waste treatment processes which involve high levels of γ-rays. The article is followed by the slides of the presentation

  10. Orthogonal model and experimental data for analyzing wood-fiber-based tri-axial ribbed structural panels in bending

    Science.gov (United States)

    Jinghao Li; John F. Hunt; Shaoqin Gong; Zhiyong Cai

    2017-01-01

    This paper presents an analysis of 3-dimensional engineered structural panels (3DESP) made from wood-fiber-based laminated paper composites. Since the existing models for calculating the mechanical behavior of core configurations within sandwich panels are very complex, a new simplified orthogonal model (SOM) using an equivalent element has been developed. This model...

  11. TU-H-CAMPUS-TeP2-03: High Sensitivity and High Resolution Fiber Based Micro-Detector for Sub-Millimeter Preclinical Dosimetry

    International Nuclear Information System (INIS)

    Izaguirre, E; Pokhrel, S; Knewtson, T; Hedrick, S

    2016-01-01

    Purpose: Current precision of small animal and cell micro-irradiators has continuously increased during the past years. Currently, preclinical irradiators can deliver sub-millimeter fields with micrometric precision but there are no water equivalent dosimeters to determine small field profiles and dose in the orthovoltage range of energies with micrometric resolution and precision. We have developed a fiber based micro-dosimeter with the resolution and dosimetric accuracy required for radiobiological research. Methods: We constructed two prototypes of micro-dosimeters based on different compositions of fiber scintillators to study the spatial resolution and dosimetric precision of small animal and cell micro-irradiators. The first has green output and the second has blue output. The blue output dosimeter has the highest sensitivity because it matches the spectral sensitivity of silicon photomultipliers. A blue detector with 500um cross section was built and tested respect to a CC01 ion chamber, film, and the 1500um green output detector. Orthovoltage fields from 1×1mm2 to 5×5mm2 were used for detector characteristics comparison. Results: The blue fiber dosimeter shows great agreement with films and matches dose measurements with the gold-standard ion chamber for 5×5mm2 fields. The detector has the appropriate sensitivity to measure fields from 1×1mm2 to larger sizes with a 1% dosimetric accuracy. The spatial resolution is in the sub-millimeter range and the spectral matching with the photomultiplier allows reducing the sensor cross section even further than the presented prototype. These results suggest that scintillating fibers combined with silicon photomultipliers is the appropriate technology to pursue micro-dosimetry for small animals and disperse cell samples. Conclusion: The constructed detectors establish a new landmark for the resolution and sensitivity of fiber based microdetectors. The validation of the detector in our small animal and cell

  12. Investigations Into the Reusability of Amidoxime-Based Polymeric Uranium Adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Li-Jung [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Science Lab.; Gill, Gary A. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Science Lab.; Strivens, Jonathan E. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Science Lab.; Wood, Jordana R. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Science Lab.; Schlafer, Nicholas J. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Science Lab.; Wai, Chien M. [Univ. of Idaho, Moscow, ID (United States); LCW Supercritical Technologies, Seattle, WA (United States); Pan, H. B. [Univ. of Idaho, Moscow, ID (United States)

    2016-09-28

    Significant advancements in amidoxime-based polymeric adsorbents to extract uranium from seawater are achieved in recent years. The success of uranium adsorbent development can help provide a sustainable supply of fuel for nuclear reactors. To bring down the production cost of this new technology, in addition to the development of novel adsorbents with high uranium capacity and manufacture cost, the development of adsorbent re-using technique is critical because it can further reduce the cost of the adsorbent manufacture. In our last report, the use of high concentrations of bicarbonate solution (3M KHCO3) was identified as a cost-effective, environmental friendly method to strip uranium from amidoxime-based polymeric adsorbents. This study aims to further improve the method for high recovery of uranium capacity in re-uses and to evaluate the performance of adsorbents after multiple re-use cycles. Adsorption of dissolved organic matter (DOM) on the uranium adsorbents during seawater exposure can hinder the uranium adsorption and slow down the adsorption rate. An additional NaOH rinse (0.5 M NaOH, room temperature) was applied after the 3 M KHCO3 elution to remove natural organic matter from adsorbents. The combination of 3 M KHCO3 elution and 0.5 M NaOH rinse significantly improves the recovery of uranium adsorption capacity in the re-used adsorbents. In the first re-use, most ORNL adsorbents tested achieve ~100% recovery by using 3 M KHCO3 elution + 0.5 M NaOH rinse approach, in comparison to 54% recovery when only 3 M KHCO3 elution was applied. A significant drop in capacity was observed when the adsorbents went through more than one re-use. FTIR spectra revealed that degradation of amidoxime ligands occurs during seawater exposure, and is more significant the longer the exposure time. Significantly elevated ratios of Ca/U and Mg/U in re-used adsorbents support the decrease in abundance of amidoxime ligands and increase carboxylate group from FT-IR analysis. The

  13. Structure of adsorbed monolayers. The surface chemical bond

    International Nuclear Information System (INIS)

    Somorjai, G.A.; Bent, B.E.

    1984-06-01

    This paper attempts to provide a summary of what has been learned about the structure of adsorbed monolayers and about the surface chemical bond from molecular surface science. While the surface chemical bond is less well understood than bonding of molecules in the gas phase or in the solid state, our knowledge of its properties is rapidly accumulating. The information obtained also has great impact on many surface science based technologies, including heterogeneous catalysis and electronic devices. It is hoped that much of the information obtained from studies at solid-gas interfaces can be correlated with molecular behavior at solid-liquid interfaces. 31 references, 42 figures, 1 table

  14. Process for producing zeolite adsorbent and process for treating radioactive liquid waste with the zeolite adsorbent

    International Nuclear Information System (INIS)

    Motojima, K.; Kawamura, F.

    1984-01-01

    Zeolite is contacted with an aqueous solution containing at least one of copper, nickel, cobalt, manganese and zinc salts, preferably copper and nickel salts, particularly preferably copper salt, in such a form as sulfate, nitrate, or chloride, thereby adsorbing the metal on the zeolite in its pores by ion exchange, then the zeolite is treated with a water-soluble ferrocyanide compound, for example, potassium ferrocyanide, thereby forming metal ferrocyanide on the zeolite in its pores. Then, the zeolite is subjected to ageing treatment, thereby producing a zeolite adsorbent impregnated with metal ferrocyanide in the pores of zeolite. The adsorbent can selectively recover cesium with a high percent cesium removal from a radioactive liquid waste containing at least radioactive cesium, for example, a radioactive liquid waste containing cesium and such coexisting ions as sodium, magnesium, calcium and carbonate ions at the same time at a high concentration. The zeolite adsorbent has a stable adsorbability for a prolonged time

  15. Method for modifying trigger level for adsorber regeneration

    Science.gov (United States)

    Ruth, Michael J.; Cunningham, Michael J.

    2010-05-25

    A method for modifying a NO.sub.x adsorber regeneration triggering variable. Engine operating conditions are monitored until the regeneration triggering variable is met. The adsorber is regenerated and the adsorbtion efficiency of the adsorber is subsequently determined. The regeneration triggering variable is modified to correspond with the decline in adsorber efficiency. The adsorber efficiency may be determined using an empirically predetermined set of values or by using a pair of oxygen sensors to determine the oxygen response delay across the sensors.

  16. Adsorbent catalytic nanoparticles and methods of using the same

    Energy Technology Data Exchange (ETDEWEB)

    Slowing, Igor Ivan; Kandel, Kapil

    2017-01-31

    The present invention provides an adsorbent catalytic nanoparticle including a mesoporous silica nanoparticle having at least one adsorbent functional group bound thereto. The adsorbent catalytic nanoparticle also includes at least one catalytic material. In various embodiments, the present invention provides methods of using and making the adsorbent catalytic nanoparticles. In some examples, the adsorbent catalytic nanoparticles can be used to selectively remove fatty acids from feedstocks for biodiesel, and to hydrotreat the separated fatty acids.

  17. An Exposed-Core Grapefruit Fibers Based Surface Plasmon Resonance Sensor

    Directory of Open Access Journals (Sweden)

    Xianchao Yang

    2015-07-01

    Full Text Available To solve the problem of air hole coating and analyte filling in microstructured optical fiber-based surface plasmon resonance (SPR sensors, we designed an exposed-core grapefruit fiber (EC-GFs-based SPR sensor. The exposed section of the EC-GF is coated with a SPR, supporting thin silver film, which can sense the analyte in the external environment. The asymmetrically coated fiber can support two separate resonance peaks (x- and y-polarized peaks with orthogonal polarizations and x-polarized peak, providing a much higher peak loss than y-polarized, also the x-polarized peak has higher wavelength and amplitude sensitivities. A large analyte refractive index (RI range from 1.33 to 1.42 is calculated to investigate the sensing performance of the sensor, and an extremely high wavelength sensitivity of 13,500 nm/refractive index unit (RIU is obtained. The silver layer thickness, which may affect the sensing performance, is also discussed. This work can provide a reference for developing a high sensitivity, real-time, fast-response, and distributed SPR RI sensor.

  18. Electrospun phase change fibers based on polyethylene glycol/cellulose acetate blends

    International Nuclear Information System (INIS)

    Chen, Changzhong; Wang, Linge; Huang, Yong

    2011-01-01

    Highlights: → Ultrafine PEG/CA phase change fibers were fabricated by electrospinning. → PEG content dramatically influenced the fiber morphology and phase change behaviors. → The electrospun fibers have excellent thermal properties for thermal energy storage. - Abstract: Ultrafine phase change fibers based on polyethylene glycol (PEG)/cellulose acetate (CA) blends in which PEG acts as a model phase change material (PCM) and CA acts as a supporting material, were successfully prepared via electrospinning. The effect of PEG content on the morphology, crystalline properties, phase change behaviors and tensile properties of the composite fibers was studied systematically by field-emission scanning electron microscopy (FE-SEM), wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and a tensile tester, respectively. The SEM observation indicates that maximum PEG content in the fibers could reach up to 70 wt%, and the morphology and average diameter of the composite fibers vary with PEG content. Thermal analysis results show that the latent heats of the phase change fibers increase with the increasing of PEG content in the fibers, and the PEG/CA fibers with high enthalpies have a good capability to regulate their interior temperature as the ambient temperature alters. Therefore, the developed phase change fibers have enormous applicable potentials in thermal energy storage and temperature regulation.

  19. Highly versatile fiber-based optical Fabry-Pérot gas sensor.

    Science.gov (United States)

    Liu, Jing; Sun, Yuze; Fan, Xudong

    2009-02-16

    We develop a versatile, compact, and sensitive fiber-based optical Fabry-Pérot (FP) gas sensor. The sensor probe is composed of a silver layer and a vapor-sensitive polymer layer that are sequentially deposited on the cleaved fiber endface, thus forming an FP cavity. The interference spectrum resulting from the reflected light at the silver-polymer and polymer-air interfaces changes when the polymer is exposed to gas analytes. This structure enables using any polymer regardless of the polymer refractive index (RI), which significantly enhances the sensor versatility. In experiments, we use polyethylene glycol (PEG) 400 (RI=1.465-1.469) and Norland Optical Adhesive (NOA) 81 (RI=1.53-1.56) as the gas sensing polymer and show drastically different sensor response to hexanol, methanol, and acetone. The estimated sensitivity for methanol vapor is 3.5 pm/ppm and 0.1 pm/ppm for PEG 400 and NOA 81, respectively, with a detection limit on the order of 1-10 ppm. Gas sensing for the analytes delivered in both continuous flow mode and pulsed mode is demonstrated.

  20. Portable, Fiber-Based, Diffuse Reflection Spectroscopy (DRS) Systems for Estimating Tissue Optical Properties.

    Science.gov (United States)

    Vishwanath, Karthik; Chang, Kevin; Klein, Daniel; Deng, Yu Feng; Chang, Vivide; Phelps, Janelle E; Ramanujam, Nimmi

    2011-02-01

    Steady-state diffuse reflection spectroscopy is a well-studied optical technique that can provide a noninvasive and quantitative method for characterizing the absorption and scattering properties of biological tissues. Here, we compare three fiber-based diffuse reflection spectroscopy systems that were assembled to create a light-weight, portable, and robust optical spectrometer that could be easily translated for repeated and reliable use in mobile settings. The three systems were built using a broadband light source and a compact, commercially available spectrograph. We tested two different light sources and two spectrographs (manufactured by two different vendors). The assembled systems were characterized by their signal-to-noise ratios, the source-intensity drifts, and detector linearity. We quantified the performance of these instruments in extracting optical properties from diffuse reflectance spectra in tissue-mimicking liquid phantoms with well-controlled optical absorption and scattering coefficients. We show that all assembled systems were able to extract the optical absorption and scattering properties with errors less than 10%, while providing greater than ten-fold decrease in footprint and cost (relative to a previously well-characterized and widely used commercial system). Finally, we demonstrate the use of these small systems to measure optical biomarkers in vivo in a small-animal model cancer therapy study. We show that optical measurements from the simple portable system provide estimates of tumor oxygen saturation similar to those detected using the commercial system in murine tumor models of head and neck cancer.

  1. Coupling of a single NV center to a fiber-based microcavity

    International Nuclear Information System (INIS)

    Christoph Becher

    2014-01-01

    The read-out of the spin state of a NV center in diamond or the transfer of quantum information between its spin and a photon would profit enormously from coupling the NV center's optical transitions to a microcavity with a highly directional output. We here report on such a coupling of a single NV center in a nanodiamond to a fiber-based, tunable microcavity at room temperature. Making use of the NV center's strongly broadened emission we operate in the regime of phonon-assisted cavity seeding and realize a widely tunable, narrow-band single photon source. A master equation model well reproduces our experimental results and predicts a transition into a Purcell-enhanced emission regime at low temperatures where up to 65% of the NV emission would be channeled into the cavity mode for our given experimental parameters. Further reducing scattering losses from the nanodiamonds could enable schemes for cavity-enhanced spin measurements or creation of entangled states. (author)

  2. The Orbital Angular Momentum Modes Supporting Fibers Based on the Photonic Crystal Fiber Structure

    Directory of Open Access Journals (Sweden)

    Hu Zhang

    2017-10-01

    Full Text Available The orbital angular momentum (OAM of light can be another physical dimension that we exploit to make multiplexing in the spatial domain. The design of the OAM mode supporting fiber attracts many attentions in the field of the space division multiplexing (SDM system. This paper reviews the recent progresses in photonic crystal fiber (PCF supporting OAM modes, and summarizes why a PCF structure can be used to support stable OAM transmission modes. The emphasis is on the circular PCFs, which possess many excellent features of transmission performance, such as good-quality OAM modes, enough separation of the effective indices, low confinement loss, flat dispersion, a large effective area, and a low nonlinear coefficient. We also compare the transmission properties between the circular PCF and the ring core fiber, as well as the properties between the OAM EDFA based on circular PCF and the OAM EDFA based on the ring core fiber. At last, the challenges and prospects of OAM fibers based on the PCF structure are also discussed.

  3. Fiber-based tissue identification for electrode placement in deep brain stimulation neurosurgery (Conference Presentation)

    Science.gov (United States)

    DePaoli, Damon T.; Lapointe, Nicolas; Goetz, Laurent; Parent, Martin; Prudhomme, Michel; Cantin, Léo.; Galstian, Tigran; Messaddeq, Younès.; Côté, Daniel C.

    2016-03-01

    Deep brain stimulation's effectiveness relies on the ability of the stimulating electrode to be properly placed within a specific target area of the brain. Optical guidance techniques that can increase the accuracy of the procedure, without causing any additional harm, are therefore of great interest. We have designed a cheap optical fiber-based device that is small enough to be placed within commercially available DBS stimulating electrodes' hollow cores and that is capable of sensing biological information from the surrounding tissue, using low power white light. With this probe we have shown the ability to distinguish white and grey matter as well as blood vessels, in vitro, in human brain samples and in vivo, in rats. We have also repeated the in vitro procedure with the probe inserted in a DBS stimulating electrode and found the results were in good agreement. We are currently validating a second fiber optic device, with micro-optical components, that will result in label free, molecular level sensing capabilities, using CARS spectroscopy. The final objective will be to use this data in real time, during deep brain stimulation neurosurgery, to increase the safety and accuracy of the procedure.

  4. Femtosecond laser fabrication of fiber based optofluidic platform for flow cytometry applications

    Science.gov (United States)

    Serhatlioglu, Murat; Elbuken, Caglar; Ortac, Bulend; Solmaz, Mehmet E.

    2017-02-01

    Miniaturized optofluidic platforms play an important role in bio-analysis, detection and diagnostic applications. The advantages of such miniaturized devices are extremely low sample requirement, low cost development and rapid analysis capabilities. Fused silica is advantageous for optofluidic systems due to properties such as being chemically inert, mechanically stable, and optically transparent to a wide spectrum of light. As a three dimensional manufacturing method, femtosecond laser scanning followed by chemical etching shows great potential to fabricate glass based optofluidic chips. In this study, we demonstrate fabrication of all-fiber based, optofluidic flow cytometer in fused silica glass by femtosecond laser machining. 3D particle focusing was achieved through a straightforward planar chip design with two separately fabricated fused silica glass slides thermally bonded together. Bioparticles in a fluid stream encounter with optical interrogation region specifically designed to allocate 405nm single mode fiber laser source and two multi-mode collection fibers for forward scattering (FSC) and side scattering (SSC) signals detection. Detected signal data collected with oscilloscope and post processed with MATLAB script file. We were able to count number of events over 4000events/sec, and achieve size distribution for 5.95μm monodisperse polystyrene beads using FSC and SSC signals. Our platform shows promise for optical and fluidic miniaturization of flow cytometry systems.

  5. Treatment of Rural Wastewater Using a Spiral Fiber Based Salinity-Persistent Sequencing Batch Biofilm Reactor

    Directory of Open Access Journals (Sweden)

    Ying-Xin Zhao

    2017-12-01

    Full Text Available Differing from municipal wastewater, rural wastewater in salinization areas is characterized with arbitrary discharge and high concentration of salt, COD, nitrogen and phosphorus, which would cause severe deterioration of rivers and lakes. To overcome the limits of traditional biological processes, a spiral fiber based salinity-persistent Sequencing Biofilm Batch Reactor (SBBR was developed and investigated with synthetic rural wastewater (COD = 500 mg/L, NH4+-N = 50 mg/L, TP = 6 mg/L under different salinity (0.0–10.0 g/L of NaCl. Results indicated that a quick start-up could be achieved in 15 days, along with sufficient biomass up to 7275 mg/L. During operating period, the removal of COD, NH4+-N, TN was almost not disturbed by salt varying from 0.0 to 10.0 g/L with stable efficiency reaching 92%, 82% and 80%, respectively. Although TP could be removed at high efficiency of 90% in low salinity conditions (from 0.0 to 5.0 g/L of NaCl, it was seriously inhibited due to nitrite accumulation and reduction of Phosphorus Accumulating Organisms (PAOs after addition of 10.0 g/L of salt. The behavior proposed in this study will provide theoretical foundation and guidance for application of SBBR in saline rural wastewater treatment.

  6. Developing strategies for the regeneration of polyethylenimine based CO{sub 2} adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Trevor C. Drage; Karl M. Smith; Ana Arenillas; Colin E. Snape [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, School of Chemical, Environmental and Mining Engineering

    2007-07-01

    Adsorption is considered to be one of the more promising technologies for capturing CO{sub 2} from flue gases. The efficient adsorption of CO{sub 2} at low partial pressures, associated with post-combustion capture, require chemical type adsorbents containing basic amine functional groups. It has been demonstrated that amine polymers, for example polyethylenimine (PEI), immobilised on various porous substrates, silica, zeolites and fly ash, are effective adsorbents for CO{sub 2}. When considering the use of adsorption for large scale CO{sub 2} capture, the ease of regeneration and the lifetime of the adsorbents are critical factors in determining their efficiency, cost and therefore feasibility for use. In this paper two approaches, thermal swing adsorption (TSA) cycles over a range of temperatures and time in an atmosphere of CO{sub 2} and thermally assisted pressure swing desorption, are explored for the regeneration of the PEI based adsorbents. The reactions occurring during the TSA regeneration of PEI based adsorbents in an atmosphere of CO{sub 2}, especially the formation of a thermostable complex between PEI and CO{sub 2} above 130{sup o}C are described. Identification of the complex by FTIR, XPS and 13C NMR and its attempted regeneration will be described. Overall, the results from this research have implications for the selection of regeneration strategies of all amine based CO{sub 2} adsorbents. 5 refs., 1 figs., 1 tab.

  7. The Dynamics and Structures of Adsorbed Surfaces

    DEFF Research Database (Denmark)

    Nielsen, M; Ellenson, W. D.; McTague, J. P.

    1978-01-01

    . Elastic neutron diffraction measurements, determining the two-dimensional structural ordering of the adsorbed films, have been performed on layers of N2, Ar, H2, D2, O2, Kr, and He. Measurements on layers of larger molecules such as CD4 and ND3 have also been reported. Inelastic neutron scattering...... measurements, studying the dynamics of the adsorbed films are only possible in a few especially favourable cases such as 36Ar and D2 films, where the coherent phonon scattering cross-sections are very large. In other cases incoherent scattering from hydrogen can give information about e.g. the mobility...

  8. Theoretical Insight of Physical Adsorption for a Single Component Adsorbent + Adsorbate System: II. The Henry Region

    KAUST Repository

    Chakraborty, Anutosh

    2009-07-07

    The Henry coefficients of a single component adsorbent + adsorbate system are calculated from experimentally measured adsorption isotherm data, from which the heat of adsorption at zero coverage is evaluated. The first part of the papers relates to the development of thermodynamic property surfaces for a single-component adsorbent + adsorbate system1 (Chakraborty, A.; Saha, B. B.; Ng, K. C.; Koyama, S.; Srinivasan, K. Langmuir 2009, 25, 2204). A thermodynamic framework is presented to capture the relationship between the specific surface area (Ai) and the energy factor, and the surface structural and the surface energy heterogeneity distribution factors are analyzed. Using the outlined approach, the maximum possible amount of adsorbate uptake has been evaluated and compared with experimental data. It is found that the adsorbents with higher specific surface areas tend to possess lower heat of adsorption (ΔH°) at the Henry regime. In this paper, we have established the definitive relation between Ai and ΔH° for (i) carbonaceous materials, metal organic frameworks (MOFs), carbon nanotubes, zeolites + hydrogen, and (ii) activated carbons + methane systems. The proposed theoretical framework of At and AH0 provides valuable guides for researchers in developing advanced porous adsorbents for methane and hydrogen uptake. © 2009 American Chemical Society.

  9. Investigations into the Effect of Current Velocity on Amidoxime-Based Polymeric Uranium Adsorbent Performance

    Energy Technology Data Exchange (ETDEWEB)

    Gill, Gary A. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Kuo, Li-Jung [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Strivens, Jonathan E. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Wood, Jordana R. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Schlafer, Nicholas J. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Tsouris, Costas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Environmental Sciences Division; Ladshaw, Austin [Georgia Inst. of Technology, Atlanta, GA (United States); Yiacoumi, Sotira [Georgia Inst. of Technology, Atlanta, GA (United States)

    2015-12-01

    The Fuel Resources Program at the U.S. Department of Energy’s (DOE), Office of Nuclear Energy (DOE-NE) is developing adsorbent technology to extract uranium from seawater. This technology is being developed to provide a sustainable and economically viable supply of uranium fuel for nuclear reactors (DOE, 2010). Among the key environmental variables to understand for adsorbent deployment in the coastal ocean is what effect flow-rates or linear velocity has on uranium adsorption capacity. The goal is to find a flow conditions that optimize uranium adsorption capacity in the shortest exposure time. Understanding these criteria will be critical in choosing a location for deployment of a marine adsorbent farm. The objective of this study was to identify at what linear velocity the adsorption kinetics for uranium extraction starts to drop off due to limitations in mass transport of uranium to the surface of the adsorbent fibers. Two independent laboratory-based experimental approaches using flow-through columns and recirculating flumes for adsorbent exposure were used to assess the effect of flow-rate (linear velocity) on the kinetic uptake of uranium on amidoxime-based polymeric adsorbent material. Time series observations over a 56 day period were conducted with flow-through columns over a 35-fold range in linear velocity from 0.29 to 10.2 cm/s, while the flume study was conducted over a narrower 11-fold range, from 0.48 to 5.52 cm/s. These ranges were specifically chosen to focus on the lower end of oceanic currents and expand above and below the linear velocity of ~ 2.5 cm/s adopted for marine testing of adsorbent material at PNNL.

  10. Volatile organic compounds adsorption using different types of adsorbent

    Directory of Open Access Journals (Sweden)

    Pimanmes Chanayotha

    2014-09-01

    Full Text Available Adsorbents were synthesized from coconut shell, coal and coke by pyrolysis followed by chemical activation process. These synthesized materials were used as adsorbents in adsorption test to determine the amount of volatile organic compounds (VOCs namely, 2-Hydroxyethyl methacrylate (HEMA, Octamethylcyclotetrasiloxane and Alkanes standard solution (C8-C20. The adsorption capacities of both synthesized adsorbents and commercial grade adsorbents (Carbotrap™ B and Carbotrap™ C were also compared. It was found that adsorbent A402, which was produced from coconut shell, activated with 40% (wt. potassium hydroxide and at activating temperature of 800°C for 1 hr, could adsorb higher amount of both HEMA and Octamethylcyclotetrasiloxane than other synthesized adsorbents. The maximum adsorption capacity of adsorbent A402 in adsorbing HEMA and Octamethylcyclotetrasiloxane were 77.87% and 50.82% respectively. These adsorption capabilities were 79.73% and 70.07% of the adsorption capacity of the commercial adsorbent Carbotrap™ B respectively. All three types of the synthesized adsorbent (A402, C302, C402 showed the capability to adsorb alkanes standard solution through the range of C8-C20 . However, their adsorption capacities were high in a specific range of C10-C11. The result from the isotherm plot was indicated that surface adsorption of synthesized adsorbent was isotherm type I while the surface adsorption of commercial adsorbent was isotherm type III.

  11. Achievement report in fiscal 2000 on research and development project for immediately effective and innovative energy environment technologies. Development of new natural gas storage technology using adsorbents; 2000 nendo sokkoteki kakushinteki energy kankyo gijutsu kenkyu kaihatsu jigyo seika hokokusho. Kyuchaku zai wo mochiita shinkina ten'nen gasu chozo gijutsu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    In relation with natural gas which contributes to preserving the environment and reducing dependence on petroleum, research and development has been performed on a storage system using adsorbents that allows storage of natural gas at higher density than conventional systems. This paper summarizes the achievements in fiscal 2000. In material development, the current fiscal year has performed the discussions on synthesis of three dimensional complexes. An adsorbent was synthesized successfully that has adsorption performance 2.5 times greater than the secondary complex. In developing an improved activated carbon, an adsorbent was synthesized successfully that has methane adsorption performance four times greater than the compressed gas, by using monolithic activated carbon that uses no binders. Carbon briquettes were manufactured for the basic testing equipment for fuel storage container of natural gas fueled automobiles. In the system development, installation was completed on a bench scale equipment for a gas holder and BOG treatment system, whereas engineering data were acquired from the single-column type high pressure test and two-column type constituent separation and storage test using natural gas. Selection was carried out on applicable vehicle types for the adsorption storage system for natural gas fueled automobiles, and the basic design was made for fabrication of containers of different shapes. (NEDO)

  12. Achievement report in fiscal 2000 on research and development project for immediately effective and innovative energy environment technologies. Development of new natural gas storage technology using adsorbents; 2000 nendo sokkoteki kakushinteki energy kankyo gijutsu kenkyu kaihatsu jigyo seika hokokusho. Kyuchaku zai wo mochiita shinkina ten'nen gasu chozo gijutsu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    In relation with natural gas which contributes to preserving the environment and reducing dependence on petroleum, research and development has been performed on a storage system using adsorbents that allows storage of natural gas at higher density than conventional systems. This paper summarizes the achievements in fiscal 2000. In material development, the current fiscal year has performed the discussions on synthesis of three dimensional complexes. An adsorbent was synthesized successfully that has adsorption performance 2.5 times greater than the secondary complex. In developing an improved activated carbon, an adsorbent was synthesized successfully that has methane adsorption performance four times greater than the compressed gas, by using monolithic activated carbon that uses no binders. Carbon briquettes were manufactured for the basic testing equipment for fuel storage container of natural gas fueled automobiles. In the system development, installation was completed on a bench scale equipment for a gas holder and BOG treatment system, whereas engineering data were acquired from the single-column type high pressure test and two-column type constituent separation and storage test using natural gas. Selection was carried out on applicable vehicle types for the adsorption storage system for natural gas fueled automobiles, and the basic design was made for fabrication of containers of different shapes. (NEDO)

  13. An optical fiber-based flexible readout system for micro-pattern gas detectors

    Science.gov (United States)

    Li, C.; Feng, C. Q.; Zhu, D. Y.; Liu, S. B.; An, Q.

    2018-04-01

    This paper presents an optical fiber-based readout system that is intended to provide a general purpose multi-channel readout solution for various Micro-Pattern Gas Detectors (MPGDs). The proposed readout system is composed of several front-end cards (FECs) and a data collection module (DCM). The FEC exploits the capability of an existing 64-channel generic TPC readout ASIC chip, named AGET, to implement 256 channels readout. AGET offers FEC a large flexibility in gain range (4 options from 120 fC to 10 pC), peaking time (16 options from 50 ns to 1 us) and sampling freqency (100 MHz max.). The DCM contains multiple 1 Gbps optical fiber serial link interfaces that allow the system scaling up to 1536 channels with 6 FECs and 1 DCM. Further scaling up is possible through cascading of multiple DCMs, by configuring one DCM as a master while other DCMs in slave mode. This design offers a rapid readout solution for different application senario. Tests indicate that the nonlinearity of each channel is less than 1%, and the equivalent input noise charge is typically around 0.7 fC in RMS (root mean square), with a noise slope of about 0.01 fC/pF. The system level trigger rate limit is about 700 Hz in all channel readout mode. When in hit channel readout mode, supposing that typically 10 percent of channels are fired, trigger rate can go up to about 7 kHz. This system has been tested with Micromegas detector and GEM detector, confirming its capability in MPGD readout. Details of hardware and FPGA firmware design, as well as system performances, are described in the paper.

  14. Fiber-based polarimetric stress sensor for measuring the Young's modulus of biomaterials

    Science.gov (United States)

    Harrison, Mark C.; Armani, Andrea M.

    2015-03-01

    Polarimetric optical fiber-based stress and pressure sensors have proven to be a robust tool for measuring and detecting changes in the Young's modulus (E) of materials in response to external stimuli, including the real-time monitoring of the structural integrity of bridges and buildings. These sensors typically work by using a pair of polarizers before and after the sensing region of the fiber, and often require precise alignment to achieve high sensitivity. The ability to perform similar measurements in natural and in engineered biomaterials could provide significant insights and enable research advancement and preventative healthcare. However, in order for this approach to be successful, it is necessary to reduce the complexity of the system by removing free-space components and the need for alignment. As the first step in this path, we have developed a new route for performing these measurements. By generalizing and expanding established theoretical analyses for these types of sensors, we have developed a predictive theoretical model. Additionally, by replacing the conventional free space components and polarization filters with a polarimeter, we have constructed a sensor system with higher sensitivity and which is semi-portable. In initial experiments, a series of polydimethylsiloxane (PDMS) samples with several base:curing agent ratios ranging from 5:1 up to 30:1 were prepared to simulate tissues with different stiffnesses. By simultaneously producing stress-strain curves using a load frame and monitoring the polarization change of light traveling through the samples, we verified the accuracy of our theoretical model.

  15. Photoemission spectroscopy of surfaces and adsorbates

    International Nuclear Information System (INIS)

    Chiang, T.C.; Kaindl, G.; Himpsel, F.J.; Eastman, D.E.

    1982-01-01

    Core level photoelectron spectroscopy is providing new information concerning the electronic properties of adsorbates and surfaces. Several examples will be discussed, including studies of adsorbed rare gas submonolayers and multilayers as well as clean metal surfaces. For rare gas multilayers adsorbed on metal surfaces, the photoelectrons and Auger electrons exhibit well-resolved increases in kinetic energy with decreasing distance between the excited atom and the substrate, allowing a direct labeling of the layers. These energy shifts are mainly due to the substrate screening effects, and can be described well by an image-charge model. For a Kr/Xe bilayer system prepared by first coating a Pd substrate with a monolayer of Kr and then overcoating with a layer of Xe, a thermally activated layer inversion process is observed when the temperature is raised, with Xe coming in direct contact with the substrate. For rare gas submonolayers adsorbed on the Al(111) surface, coverage-dependent core level shift and work function measurements provide information about the adatom spatial distributions, polarizabilities, and dipole moments for the ground and excited states. We have also studied the 2p core level shifts for a clean Al(001) surface relative to the bulk. The shifts have a large contribution from the initial-state effects

  16. Heterogeneous membranes filled with hypercrosslinked microparticle adsorbent

    Czech Academy of Sciences Publication Activity Database

    Hradil, Jiří; Krystl, V.; Hrabánek, P.; Bernauer, B.; Kočiřík, Milan

    2005-01-01

    Roč. 65, 1-2 (2005), s. 57-68 ISSN 1381-5148 R&D Projects: GA ČR GA104/03/0680 Institutional research plan: CEZ:AV0Z40500505 Keywords : heterogeneous membranes * hypercrosslinked adsorbent * microparticle s Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.565, year: 2005

  17. The adsorber loop concept for the contact between seawater and adsorber granulate

    International Nuclear Information System (INIS)

    Koske, P.H.; Ohlrogge, K.

    1984-01-01

    The present paper deals with the so-called ''adsorber loop concept'' in which the adsorber granulate is carried along with the seawater to be processed in a loop-like configuration and is separated again from the depleted water before this is leaving the adsorption unit. This concept enables high seawater velocities thus reducing the required bed area. Theoretical considerations are presented together with experimental results from field tests. (orig.) [de

  18. Electronic spectral properties of surfaces and adsorbates and atom-adsorbate van der Waals interactions

    International Nuclear Information System (INIS)

    Lovric, D.; Gumhalter, B.

    1988-01-01

    The relevance of van der Waals interactions in the scattering of neutral atoms from adsorbates has been recently confirmed by highly sensitive molecular-beam techniques. The theoretical descriptions of the collision dynamics which followed the experimental studies have necessitated very careful qualitative and quantitative examinations and evaluations of the properties of atom-adsorbate van der Waals interactions for specific systems. In this work we present a microscopic calculation of the strengths and reference-plane positions for van der Waals potentials relevant for scattering of He atoms from CO adsorbed on various metallic substrates. In order to take into account the specificities of the polarization properties of real metals (noble and transition metals) and of chemisorbed CO, we first calculate the spectra of the electronic excitations characteristic of the respective electronic subsystems by using various data sources available and combine them with the existing theoretical models. The reliability of the calculated spectra is then verified in each particular case by universal sum rules which may be established for the electronic excitations of surfaces and adsorbates. The substrate and adsorbate polarization properties which derive from these calculations serve as input data for the evaluation of the strengths and reference-plane positions of van der Waals potentials whose computed values are tabulated for a number of real chemisorption systems. The implications of the obtained results are discussed in regard to the atom-adsorbate scattering cross sections pertinent to molecular-beam scattering experiments

  19. Investigations into the Reusability of Amidoxime-Based Polymeric Adsorbents for Seawater Uranium Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Li-Jung [Marine; Pan, Horng-Bin [Department; Wai, Chien M. [Department; Byers, Margaret F. [Nuclear; Schneider, Erich [Nuclear; Strivens, Jonathan E. [Marine; Janke, Christopher J. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831, United States; Das, Sadananda [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831, United States; Mayes, Richard T. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831, United States; Wood, Jordana R. [Marine; Schlafer, Nicholas [Marine; Gill, Gary A. [Marine

    2017-09-29

    The ability to re-use amidoxime-based polymeric adsorbents is a critical component in reducing the overall cost of the technology to extract uranium from seawater. This report describes an evaluation of adsorbent reusability in multiple re-use (adsorption/stripping) cycles in real seawater exposures with potassium bicarbonate (KHCO3) elution using several amidoxime-based polymeric adsorbents. The KHCO3 elution technique achieved ~100% recovery of uranium adsorption capacity in the first re-use. Subsequent re-uses showed significant drops in adsorption capacity. After the 4th re-use with the ORNL AI8 adsorbent, the 56-day adsorption capacity dropped to 28% of its original capacity. FTIR spectra revealed that there was a conversion of the amidoxime ligands to carboxylate groups during extended seawater exposure, becoming more significant with longer the exposure time. Ca and Mg adsorption capacities also increased with each re-use cycle supporting the hypothesis that long term exposure resulted in converting amidoxime to carboxylate, enhancing the adsorption of Ca and Mg. Shorter seawater exposure (adsorption/stripping) cycles (28 vs. 42 days) had higher adsorption capacities after re-use, but the shorter exposure cycle time did not produce an overall better performance in terms of cumulative exposure time. Recovery of uranium capacity in re-uses may also vary across different adsorbent formulations. Through multiple re-use the adsorbent AI8 can harvest 10 g uranium/kg adsorbent in ~140 days, using a 28-day adsorption/stripping cycle, a performance much better than would be achieved with a single use of the adsorbent through very long-term exposure (saturation capacity = 7.4 g U/kg adsorbent). A time dependent seawater exposure model to evaluate the cost associated with reusing amidoxime-based adsorbents in real seawater exposures was developed. The cost to extract uranium from seawater ranged from $610-830/kg U was predicted. Model simulation suggests that a short

  20. Adsorbents for radioactive organic solvent wastes

    International Nuclear Information System (INIS)

    Ichinose, Shigeo; Kiribayashi, Takehiko.

    1986-01-01

    Purpose: To enable to settle radioactive solvents such as tributyl phosphate (TBP) and n-dodecane as they are without using hydrophobicizing agent such as quaternary ammonium salts. Constitution: The adsorbents are prepared by replacing interlaminer ions of swelling-type synthetic mica with alkaline earth metals or metal ions. For instance, synthetic micas introduced with Zr 4+ or Ca 2+ between the layers provide quite different functions from those of starting materials due to the properties of ions introduced between the layers. That is, they provide an intense affinity to organic phosphates such as TBP and transform into material showing a property of adsorbing and absorbing them. Particularly, the fixing nature to the phosphor content constituting TBP is significantly increased. (Horiuchi, T.)

  1. Zeolites as alcohol adsorbents from aqueous solutions

    Directory of Open Access Journals (Sweden)

    Cekova Blagica

    2006-01-01

    Full Text Available The potential usage of zeolites as adsorbents for the removal of organic molecules from water was investigated in a series of experiments with aqueous solutions of lower alcohols. This could represent a simple solution to the problem of cleaning up industrial wastewater as well as recovering valuable chemicals at relatively low costs. Adsorption isotherms of the Langmuir type were applied, and calculations showed that the amount of propanol adsorbed on silicalite corresponded to approximately 70% of the pore volume. The adsorption process is simple, and recovery of the more concentrated products is easily done by heat treatment and/or at lowered pressures. Adsorption experiments with aqueous acetone showed that silicalite had approximately the same adsorption capacity for acetone as for n-propanol. Heats of adsorption were determined calorimetrically.

  2. Green Adsorbents for Wastewaters: A Critical Review

    Directory of Open Access Journals (Sweden)

    George Z. Kyzas

    2014-01-01

    Full Text Available One of the most serious environmental problems is the existence of hazardous and toxic pollutants in industrial wastewaters. The major hindrance is the simultaneous existence of many/different types of pollutants as (i dyes; (ii heavy metals; (iii phenols; (iv pesticides and (v pharmaceuticals. Adsorption is considered to be one of the most promising techniques for wastewater treatment over the last decades. The economic crisis of the 2000s led researchers to turn their interest in adsorbent materials with lower cost. In this review article, a new term will be introduced, which is called “green adsorption”. Under this term, it is meant the low-cost materials originated from: (i agricultural sources and by-products (fruits, vegetables, foods; (ii agricultural residues and wastes; (iii low-cost sources from which most complex adsorbents will be produced (i.e., activated carbons after pyrolysis of agricultural sources. These “green adsorbents” are expected to be inferior (regarding their adsorption capacity to the super-adsorbents of previous literature (complex materials as modified chitosans, activated carbons, structurally-complex inorganic composite materials etc., but their cost-potential makes them competitive. This review is a critical approach to green adsorption, discussing many different (maybe in some occasions doubtful topics such as: (i adsorption capacity; (ii kinetic modeling (given the ultimate target to scale up the batch experimental data to fixed-bed column calculations for designing/optimizing commercial processes and (iii critical techno-economical data of green adsorption processes in order to scale-up experiments (from lab to industry with economic analysis and perspectives of the use of green adsorbents.

  3. Generating Atomistic Slab Surfaces with Adsorbates

    Science.gov (United States)

    2017-12-01

    slabs of various thickness and with various vacuum spacing need be calculated. This can occur in serial or simultaneously . If performed in serial, the...the user. Although the optimization of the slab thickness and vacuum padding can be done simultaneously , it is more computationally conservative to...monolayer is a slab (True if slab), the type of mesh desired (adsorbates.py was written for “Gamma”), how detailed the mesh should be (in units of inverse

  4. Green Adsorbents for Wastewaters: A Critical Review

    Science.gov (United States)

    Kyzas, George Z.; Kostoglou, Margaritis

    2014-01-01

    One of the most serious environmental problems is the existence of hazardous and toxic pollutants in industrial wastewaters. The major hindrance is the simultaneous existence of many/different types of pollutants as (i) dyes; (ii) heavy metals; (iii) phenols; (iv) pesticides and (v) pharmaceuticals. Adsorption is considered to be one of the most promising techniques for wastewater treatment over the last decades. The economic crisis of the 2000s led researchers to turn their interest in adsorbent materials with lower cost. In this review article, a new term will be introduced, which is called “green adsorption”. Under this term, it is meant the low-cost materials originated from: (i) agricultural sources and by-products (fruits, vegetables, foods); (ii) agricultural residues and wastes; (iii) low-cost sources from which most complex adsorbents will be produced (i.e., activated carbons after pyrolysis of agricultural sources). These “green adsorbents” are expected to be inferior (regarding their adsorption capacity) to the super-adsorbents of previous literature (complex materials as modified chitosans, activated carbons, structurally-complex inorganic composite materials etc.), but their cost-potential makes them competitive. This review is a critical approach to green adsorption, discussing many different (maybe in some occasions doubtful) topics such as: (i) adsorption capacity; (ii) kinetic modeling (given the ultimate target to scale up the batch experimental data to fixed-bed column calculations for designing/optimizing commercial processes) and (iii) critical techno-economical data of green adsorption processes in order to scale-up experiments (from lab to industry) with economic analysis and perspectives of the use of green adsorbents. PMID:28788460

  5. Adsorbate Diffusion on Transition Metal Nanoparticles

    Science.gov (United States)

    2015-01-01

    correlation is a Bronsted-Evans-Polanyi ( BEP )- type of correlation, similar to other BEP correlations established earlier for surface-catalyzed bond- breaking...bond-making reactions.6-9 The universal BEP -type correlation is independent of the nature of the adsorbed species and that of the metal surface. For...a certain class of surface-catalyzed reactions, the existence of a BEP -type correlation reflects a similarity between the geometry of the transition

  6. Theoretical Insight of Physical Adsorption for a Single-Component Adsorbent + Adsorbate System: I. Thermodynamic Property Surfaces

    KAUST Repository

    Chakraborty, Anutosh; Saha, Bidyut Baran; Ng, Kim Choon; Koyama, Shigeru; Srinivasan, Kandadai

    2009-01-01

    Thermodynamic property surfaces for a single-component adsorbent + adsorbate system are derived and developed from the viewpoint of classical thermodynamics, thermodynamic requirements of chemical equilibrium, Gibbs law, and Maxwell relations

  7. Biological adsorbent for water decontamination from uranium

    Energy Technology Data Exchange (ETDEWEB)

    Jilek, R [Vyzkumny Ustav Veterinarniho Lekarstvi, Brno-Medlanky (Czechoslovakia); Fuska, J; Nemec, P [Slovenska Vysoka Skola Technicka, Bratislava (Czechoslovakia). Chemickotechnologicka Fakulta

    1978-01-01

    A study was made into the capacity of native and heat-denaturated mycelium to adsorb uranium salts from solutions and into the effect of uranium on the growth of the microorganism biomass. The presence of uranium did not inhibit the growth of Penicillium and Aspergillus strains used at a concentration of up to 5x10/sup -4/ M/dm/sup 3/. Uranium added to a nutrient medium produced complexes with phosphorus ions which were adsorbed on the surface of growing hyphae, thus the removal of the mycelium also removed uranium. The results of the experiments with denaturated mycelium of the same strains suggested that uranium was also bound to the biomass with chemical bonds so that mycelium acted as a ''multifunction ion exchanger'' from which adsorbed uranium can be removed step by step by elution. A sorbent of a three-dimensional structure could be prepared from a dried native mycelium using reinforcing resins, which prevented leakage of the biomass. Uranium sorption by biosorbents is a function of the concentration of the cation sorbed and of the pH of the solution.

  8. Biological adsorbent for water decontamination from uranium

    International Nuclear Information System (INIS)

    Jilek, R.; Fuska, J.; Nemec, P.

    1978-01-01

    A study was made into the capacity of native and heat-denaturated mycelium to adsorb uranium salts from solutions and into the effect of uranium on the growth of the microorganism biomass. The presence of uranium did not inhibit the growth of Penicillium and Aspergillus strains used at a concentration of up to 5x10 -4 M/dm 3 . Uranium added to a nutrient medium produced complexes with phosphorus ions which were adsorbed on the surface of growing hyphae, thus the removal of the mycelium also removed uranium. The results of the experiments with denaturated mycelium of the same strains suggested that uranium was also bound to the biomass with chemical bonds so that mycelium acted as a ''multifunction ion exchanger'' from which adsorbed uranium can be removed step by step by elution. A sorbent of a three-dimensional structure could be prepared from a dried native mycelium using reinforcing resins, which prevented leakage of the biomass. Uranium sorption by biosorbents is a function of the concentration of the cation sorbed and of the pH of the solution. (author)

  9. Characterisation of lignite as an industrial adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Ying Qi; Andrew F.A. Hoadley; Alan L. Chaffee; Gil Garnier [Monash University, Clayton, Vic. (Australia). Department of Chemical Engineering

    2011-04-15

    An alternative use of the abundant and inexpensive lignite (also known as brown coal) as an industrial adsorbent has been characterised. The adsorptive properties of two Victorian lignite without any pre-treatment were investigated using the cationic methylene blue dye as a model compound in aqueous solutions. Two commercial activated carbon products were also studied for comparison. The adsorption equilibrium of the four adsorbents was better described by the Langmuir isotherm model than the Freundlich model. The adsorption capacities of the two untreated lignite adsorbents, Loy Yang and Yallourn, calculated using Langmuir isotherms were 286 and 370 mg/g, respectively, higher than a coconut shell-based activated carbon (167 mg/g), but lower than a coal-based activated carbon (435 mg/g). Surface area results suggested that larger micropores and mesopores were important for achieving good methylene blue adsorption by the activated carbons. However, FTIR and cation exchange capacity analyses revealed that, for the lignite, chemical interactions between lignite surface functional groups and methylene blue molecules occurred, thereby augmenting its adsorption capacity. 63 refs., 3 figs., 7 tabs.

  10. Type of adsorbent and column height in adsorption process of used cooking oil

    Science.gov (United States)

    Hasnelly, Hervelly, Taufik, Yusman; Melany, Ivo Nila

    2015-12-01

    The purpose of this research was to find out the best adsorbent and column height that can adsorb color and soluble impurities substances in used cooking oil. This research was meant for knowledge development of refined cooking oil technology. The used of this research was giving out information on the recycling process of used cooking oil. Research design used 2 × 2 factorial pattern in randomized group design with 6 repetitions. The first factor is adsorbent type (J) that consist of activated carbon (J1) and Zeolit (J2). The second factor is column height (K) with variations of 15 cm (k1) and 20 cm (k2). Chemical analysis parameter are free fatty acid, water content and saponification value. Physical parameter measurement was done on color with Hunter Lab system analysis and viscosity using viscometer method. Chemical analysis result of preliminary research on used cooking oil showed water content of 1,9%, free fatty acid 1,58%, saponification value 130,79 mg KOH/g oil, viscosity 0,6 d Pas and color with L value of -27,60, a value 1,04 and b value 1,54. Result on main research showed that adsorbent type only gave effect on water content whereas column height and its interaction was not gave significant effect on water content. Interaction between adsorbent type (J) and column height (K) gave significant effect to free fatty acid, saponification value, viscosity and color for L, a and b value of recycled cooking oil.

  11. Enhancement of mass transfer by ultrasound: Application to adsorbent regeneration and food drying/dehydration.

    Science.gov (United States)

    Yao, Ye

    2016-07-01

    The physical mechanisms of heat and mass transfer enhancement by ultrasound have been identified by people. Basically, the effect of 'cavitation' induced by ultrasound is the main reason for the enhancement of heat and mass transfer in a liquid environment, and the acoustic streaming and vibration are the main reasons for that in a gaseous environment. The adsorbent regeneration and food drying/dehydration are typical heat and mass transfer process, and the intensification of the two processes by ultrasound is of complete feasibility. This paper makes an overview on recent studies regarding applications of power ultrasound to adsorbent regeneration and food drying/dehydration. The concerned adsorbents include desiccant materials (typically like silica gel) for air dehumidification and other ones (typically active carbon and polymeric resin) for water treatment. The applications of ultrasound in the regeneration of these adsorbents have been proved to be energy saving. The concerned foods are mostly fruits and vegetables. Although the ultrasonic treatment may cause food degradation or nutrient loss, it can greatly reduce the food processing time and decrease drying temperature. From the literature, it can be seen that the ultrasonic conditions (i.e., acoustic frequency and power levels) are always focused on during the study of ultrasonic applications. The increasing number of relevant studies argues that ultrasound is a very promising technology applied to the adsorbent regeneration and food drying/dehydration. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Application of low-cost adsorbents for dye removal--a review.

    Science.gov (United States)

    Gupta, V K; Suhas

    2009-06-01

    Dyes are an important class of pollutants, and can even be identified by the human eye. Disposal of dyes in precious water resources must be avoided, however, and for that various treatment technologies are in use. Among various methods adsorption occupies a prominent place in dye removal. The growing demand for efficient and low-cost treatment methods and the importance of adsorption has given rise to low-cost alternative adsorbents (LCAs). This review highlights and provides an overview of these LCAs comprising natural, industrial as well as synthetic materials/wastes and their application for dyes removal. In addition, various other methods used for dye removal from water and wastewater are also complied in brief. From a comprehensive literature review, it was found that some LCAs, in addition to having wide availability, have fast kinetics and appreciable adsorption capacities too. Advantages and disadvantages of adsorbents, favourable conditions for particular adsorbate-adsorbent systems, and adsorption capacities of various low-cost adsorbents and commercial activated carbons as available in the literature are presented. Conclusions have been drawn from the literature reviewed, and suggestions for future research are proposed.

  13. Characteristics of Microorganism's Fouling on Lithium Adsorbents in Okgye Harbor, Gangneung, Korea

    Science.gov (United States)

    Kim, J.; Yoon, H.; Kong, M.; Yoon, B.; Ryu, J.; Chung, K.; Kim, B.

    2013-12-01

    Marine microorganisms bring about serious ramification for nautical industry such as marine construction. Interaction of bacteria and phytoplankton causes biofouling to marine environments. To understand the marine microorganism's reaction on the inorganic surface, the experimental work carried out in pilot plant for lithium recovery field at Okgye Harbor, Gangneung, Korea through seasonal interval. To inquiry into the surface's effect for lithium recovery adsorbents by bacterial communities and phytoplankton, disk type inorganic adsorbents were immersed in same site at depth of 5 m for 7 days, 14 days and 21 days. Culturable marine bacteria were isolated and identified by 16S rRNA sequencing. Also, size and shape of marine organisms and the adsorption circumstance were investigated by SEM and CLSM (confocal laser scanning microscope). At longer exposure time of adsorbents, increase the bacterial number of individual. Vibrio sp., represented dominant species of biofouling after 21 days and marine phytoplankton increased 7 times after 7 days. Size of phytoplankton were about 50 ~ 100 μm in 0.25 mm2 area of lithium adsorbents. To increase lithium recovery rate of lithium adsorbents and to minimize the biofouling effects, it is necessary to conduct consistently field monitoring. Acknowledgments This research was supported by the national research project titled 'The Development of Technology for Extraction of Resources Dissolved in Seawater' of the Korea Institute of Geoscience and Mineral Resources (KIGAM) funded by the Ministry of Ocean and Fisheries.

  14. The adsorber loop concept for the contact between seawater and adsorber granulate

    International Nuclear Information System (INIS)

    Koske, P.H.; Ohlrogge, K.

    1984-01-01

    For the production of 1 kg uranium from seawater about 10 9 kg seawater - depending on the extraction efficiency - have to be processed in a production plant. Such high seawater flows have to be put through adsorber beds the area of which depends on the flow velocity of the water in the bed. For a typical polyamidoxim (PAO) adsorber granulate with a grain size distribution of 0.3 to 1.2 mm the velocity in a fluidized bed is limited to about 1 cm/s in order to prevent carry out of the adsorber material. The consequences of this rather low bed velocity are large and expensive bed areas for technical production plants. The present paper deals with the so-called ''adsorber loop concept'' in which the adsorber granulate is carried along with the seawater to be processed in a loop-like configuration and is separated again from the water before this is leaving the adsorption unit. This concept enables considerably higher seawater velocities thus reducing the bed area. Theoretical considerations are presented together with experimental results from field tests. (author)

  15. Removal of adsorbent particles od copper ions by Jet flotation

    International Nuclear Information System (INIS)

    Santander, M.; Tapia, P.; Pavez, O.; Valderrama, L.; Guzman, D.

    2009-01-01

    The present study shows the results obtained on the removal of copper ions from synthetic effluents by using the adsorbent particles flotation technique (APF) in a Jet flotation cell (Jameson type). In a typical experimental run, a mineral with high quartz content was used as adsorbent particles in the adsorption and flotation experiments, to determine optimal pH conditions, adsorbent particles concentration; flotation reagents dosage and air/effluent flow ratio for applying in the Jet cell to maximize the efficiency of copper ions adsorptions and the removal of particles adsorbents containing the absorbed copper ions. The results indicate the at pH>7 and at adsorbent particles concentration of 2 kg.m - 3, 99% of copper ions is adsorbed and, when the air/effluent flow ratio applied in the Jet cell is 0,2, 98% of absorbent particles containing the adsorbed copper ions is removed. (Author) 39 refs.

  16. Preparation of carbon dioxide adsorbents from the chemical activation of urea-formaldehyde and melamine-formaldehyde resins

    Energy Technology Data Exchange (ETDEWEB)

    T.C. Drage; A. Arenillas; K.M. Smith; C. Pevida; S. Piippo; C.E. Snape [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, School of Chemical, Environmental and Mining Engineering

    2007-01-15

    Adsorption is considered to be one of the more promising technologies for the capture of CO{sub 2} from flue gases. In general, nitrogen enrichment is reported to be effective in enhancing the specific adsorbent-adsorbate interaction for CO{sub 2}. Nitrogen enriched carbons were produced from urea-formaldehyde and melamine-formaldehyde resins polymerised in the presence of K{sub 2}CO{sub 3} as a chemical activation agent, with activation undertaken over a range of temperatures. CO{sub 2} adsorption capacity was determined to be dependent upon both textural properties and more importantly nitrogen functionality. Adsorbents capable of capturing above 8 wt.% CO{sub 2} at 25{sup o}C were produced from the chemical activation of urea-formaldehyde resin at 500{sup o}C. Chemical activation seems to produce more effective adsorbents than CO{sub 2} activation. 29 refs., 4 figs., 3 tabs.

  17. New Fiber Materials with Sorption Capacity at 5.0 g-U/kg Adsorbent under Marine Testing Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Tomonori [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Brown, S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Das, Sadananda [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mayes, Richard T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Janke, Christopher James [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dai, Sheng [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kuo, Li-Jung [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Strivens, Jonathan E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schlafer, Nicholas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wood, J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gill, G. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Flicker Byers, M. [Univ. of Texas, Austin, TX (United States); Schneider, Eric [Univ. of Texas, Austin, TX (United States)

    2016-03-30

    The Fuel Resources program of the Fuel Cycle Research and Development program of the Office of Nuclear Energy (NE) has focused on assuring that nuclear fuel resources are available in the United States for a long term. An immense source of uranium is seawater, which contains an estimated amount of 4.5 billion tonnes of dissolved uranium. Extraction of the uranium resource in seawater can provide a price cap and ensure centuries of uranium supply for future nuclear energy production. NE initiated a multidisciplinary program with participants from national laboratories, universities, and research institutes to enable technical breakthroughs related to uranium recovery from seawater. The goal is to develop advanced adsorbents to make the seawater uranium recovery technology a cost competitive, viable technology. Under this program, Oak Ridge National Laboratory (ORNL) has developed several novel adsorbents, which enhanced the uranium capacity 4-5 times from the state-of-the art Japanese adsorbents. Uranium exists uniformly at a concentration of ~3.3 ppb in seawater. Because of the vast volume of the oceans, the total estimated amount of uranium in seawater is approximately 1000 times larger than its amount in terrestrial resources. However, due to the low concentration, a significant challenge remains for making the extraction of uranium from seawater a commercially viable alternative technology. The biggest challenge for this technology to overcome to efficiently reduce the extraction cost is to develop adsorbents with increased uranium adsorption capacity. Two major approaches were investigated for synthesizing novel adsorbents with enhanced uranium adsorption capacity. One method utilized conventional radiation induced graft polymerization (RIGP) to synthesize adsorbents on high-surface area trunk fibers and the other method utilized a chemical grafting technique, atom-transfer radical polymerization (ATRP). Both approaches have shown promising uranium extraction

  18. Fiber-based coherent polarization beam combining with cascaded phase-locking and polarization-transforming controls

    Science.gov (United States)

    Yang, Yan; Geng, Chao; Li, Feng; Huang, Guan; Li, Xinyang

    2018-05-01

    In this paper, the fiber-based coherent polarization beam combining (CPBC) with cascaded phase-locking (PL) and polarization-transforming (PT) controls was proposed to combine imbalanced input beams where the number of the input beams is not binary, in which the PL control was performed using the piezoelectric-ring fiber-optic phase compensator, and the PT control was realized by the dynamic polarization controller, simultaneously. The principle of the proposed CPBC was introduced. The performance of the proposed CPBC was analyzed in comparison with the CPBC based on PL control and the CPBC based on PT control. The basic experiment of CPBC of three laser beams was carried out to validate the feasibility of the proposed CPBC, where cascaded controls of PL and PT were implemented based on stochastic parallel gradient descent algorithm. Simulation and experimental results show that the proposed CPBC incorporates the advantages of the two previous CPBC schemes and performs well in the closed loop. Moreover, the expansibility and the application of the proposed CPBC were validated by scaling the CPBC to combine seven laser beams. We believe that the proposed fiber-based CPBC with cascaded PL and PT controls has great potential in free space optical communications employing the multi-aperture receiver with asymmetric structure.

  19. Development of adsorbents for recovery of uranium from seawater

    International Nuclear Information System (INIS)

    Egawa, Hiroaki; Furusaki, Shintaro.

    1987-01-01

    The largest subject for putting the extraction of uranium from seawater in practical use is the development of high performance adsorbents for uranium. In this paper, the way of thinking about the development of adsorbents for extracting uranium from seawater and the recent reports on this subject are described. Next, the research on the adsorbing capacity and adsorbing rate of the adsorbents developed so far is summarized, and the way of thinking about the evaluation of adsorbent performance which is the base of the design of a system for extracting uranium from seawater is explained, taking amidoxime type adsorbent as the example. For Japan where energy resources are scant, the uranium contained in seawater, which is estimated to be about 4.2 billion t, is the most luring important element. Uranium is contained in seawater is very low concentration of 3 ppb, and exists as anion complex salt. In 1960s, the Harwell Atomic Energy Research Establishment in UK found out that titanium oxide hydrate is the most promising as the adsorbent. Also a number of organic absorbents have been developed. In order to bring adsorbents in contact with seawater, pumping, ocean current and wave force are utilized. Adsorbents are in spherical, fiber and film forms, and held as fixed beds and fluidized beds. (Kako, I.) 48 refs

  20. Development of adsorbent for C-14 Gas trapping and characteristics evaluation

    International Nuclear Information System (INIS)

    Park, Geun Il; Kim, I. T.; Kim, K. W.

    2006-08-01

    Desorption characteristics of C-14 adsorbed on spent resin as H 14 CO 3 ion type by applying various stripping solutions were analyzed, and some experiments for gasification of C-14 to CO 2 gas with were also performed. Based on these results, the process concept for spent resin treatment was suggested. Real spent resin was prepared from sampling in storage tank in site 1 of Wolseung Nuclear Power Plant. Desorption characteristics of C-14 and cations of Cs, Co from spent IRN-150 resin was evaluated. Desorption efficiency of C-14 from spent resin by using H 3 PO 4 desorption solution was over 96% regardless of C-14 amount on initial spent resin when comparing a activity of C-14 on initial spent resin. Also, desorption percent of cation of Cs, Co from anion ion-exchange resin (IRN-77) showed that Co-60 was below 1%, Cs-134, 137 was in a range of 2 ∼ 5%. Fundamental studies include an development of adsorbent manufacturing technology and its performance evaluation for C-14 gas trapping, the adsorption process by adopting gas circulation method was suggested for the design of 14 CO 2 gas treatment system generated from spent resin treatment process. In order to predict adsorbent performance of CO 2 trapping, modelling was carried out to verify the breakthrough curves of CO 2 trapping by using soda lime adsorbent. The effect of humidity on CO 2 trapping by using soda lime adsorbent was modelled via chemical reaction in porous media. Assessment of the state-of-the-arts on the solidification of the used adsorbent showed that the cement matrix would be the best-available binder from the view points of the matrix compatibility, properties of the final waste form, simplicity of the process and relatively low cost

  1. Theoretical Insight of Physical Adsorption for a Single Component Adsorbent + Adsorbate System: II. The Henry Region

    KAUST Repository

    Chakraborty, Anutosh; Saha, Bidyut Baran; Ng, Kim Choon; Koyama, Shigeru; Srinivasan, Kandadai

    2009-01-01

    evaluated and compared with experimental data. It is found that the adsorbents with higher specific surface areas tend to possess lower heat of adsorption (ΔH°) at the Henry regime. In this paper, we have established the definitive relation between Ai and ΔH

  2. Natural adsorbents of dyes from aqueous solution

    Science.gov (United States)

    Rahmani, Meryem; El Hajjaji, souad; Dahchour, Abdelmalek; El M'Rabet, Mohammadine

    2017-04-01

    Contamination of natural waters is a current environmental problem and lot of work has been done to find methods for its, prevention and remediation such as ionic exchange, adsorption on active carbon, filtration, electrolysis, biodegradation …etc. Adsorption is one of the most applied methods according to its effectiveness and easy management. Some adsorbents with good properties such as active alumina, zeolites, crop residues … etc, are suitable to substitute usual active carbon. This study aimed at the removal of dyes using oil shale as natural support, and its optimization by factorial experiment. Three factors were considered namly:pollutant concentration, pH and weight of the adsorbent. Tests have been performed with cationic and anionic dyes. Experimental results show that pseudo-first-order kinetic model provided the best fit to the experimental data for the adsorption by the oil shale. Langmuir, Freundlich and Temkin isotherm models were tested to fit experimental data, the adsorption equilibrium was well described by Freundlich isotherm for methylorange and Temkin for methyl blue. Analysis were completed by oil shale characterization educing XRD, IR, XRF techniques, and cationic exchange capacity.

  3. Optimizing heterosurface adsorbent synthesis for liquid chromatography

    Science.gov (United States)

    Bogoslovskii, S. Yu.; Serdan, A. A.

    2016-03-01

    The structural and geometric parameters of a silica matrix (SM) for the synthesis of heterosurface adsorbents (HAs) are optimized. Modification is performed by shielding the external surfaces of alkyl-modified silica (AS) using human serum albumin and its subsequent crosslinking. The structural and geometric characteristics of the SM, AS, and HA are measured via low-temperature nitrogen adsorption. It is found that the structural characteristics of AS pores with diameters D 9 nm reduces significantly due to adsorption of albumin. It is concluded that silica gel with a maximum pore size distribution close to 5 nm and a minimal proportion of pores with D > 9 nm is optimal for HA synthesis; this allows us to achieve the greatest similarity between the chromatographic retention parameters for HA and AS. The suitability of the synthesized adsorbents for analyzing drugs in biological fluids through direct sample injection is confirmed by chromatography. It was found that the percentage of the protein fraction detected at the outlet of the chromatographic column is 98%.

  4. New type of amidoxime-group-containing adsorbent for the recovery of uranium from seawater. III. Recycle use of adsorbent

    International Nuclear Information System (INIS)

    Omichi, H.; Katakai, A.; Sugo, T.; Okamoto, J.

    1986-01-01

    An amidoxime-group adsorbent for recovering uranium from seawater was made by radiation-induced graft polymerization of acrylonitrile onto polymeric fiber, followed by amidoximation. Uranium adsorption of the adsorbent contacted with seawater in a column increased with the increase in flow rate, then leveled off. The relationship between uranium adsorption in a batch process and the ratio of the amount of seawater to that of adsorbent was found to be effective in evaluating adsorbent contacted with any amount of seawater. The conditioning of the adsorbent with an alkaline solution at higher temperature (∼80 0 C) after the acid desorption recovered the adsorption ability to the original level. This made it possible to apply the adsorbent to recycle use. On the other hand, the adsorbent conditioned at room temperature or that without conditioning lost adsorption ability during recycle use. The increase in water uptake was observed as one of the physical changes produced during recycle use of the alkaline-conditioned adsorbent, while the decrease in water uptake was observed with the unconditioned adsorbent. The IR spectra of the adsorbent showed a probability of reactions of amidoxime groups with acid and alkaline solutions, which can explain the change in uranium adsorption during the adsorption-desorption cycle

  5. Cost analysis of seawater uranium recovered by a polymeric adsorbent system

    International Nuclear Information System (INIS)

    Schneider, E.; Lindner, H.; Sachde, D.; Flicker, M.

    2014-01-01

    In tandem with its adsorbent development and marine testing efforts, the United States Department of Energy, Office of Nuclear Energy, routinely updates and expands its cost analysis of technologies for extracting uranium from seawater. If informed by repeatable data from field tests, a rigorous cost analysis can convincingly establish seawater uranium as a “backstop” to conventional uranium resources. A backstop provides an essentially unlimited supply of an otherwise exhaustible resource. Its role is to remove the uncertainty around the long-term sustainability of the resource. The cost analysis ultimately aims to demonstrate a uranium production cost that is sustainable for the nuclear power industry, with no insurmountable technical or environmental roadblocks. It is also a tool for guiding further R&D, identifying inputs and performance factors where further development would offer the greatest reduction in costs and/or uncertainties. A life cycle discounted cash flow methodology is used to calculate the uranium production cost and its uncertainty from the costs of fundamental inputs including chemicals and materials, labor, equipment, energy carriers and facilities. The inputs themselves are defined by process flow models of the adsorbent fabrication and grafting, mooring at sea, recovery, and elution and purification steps in the seawater uranium recovery process. Pacific Northwest National Laboratory (PNNL) has carried out marine tests of the Oak Ridge National Laboratory amidoxime grafted polymer adsorbent in natural seawater. Multiple test campaigns demonstrated that after 60 days of immersion the uranium uptake averaged 3090 ± 310 μg U/g of adsorbent. Past ocean experiments on similar material by the Japan Atomic Energy Agency (JAEA) demonstrated that the adsorbent may be used in the sea six times before being replaced, with 5% uptake degradation per reuse. The mooring and recovery system envisioned for the adsorbent is similar to one proposed by

  6. Creation of the technical adsorbent from local raw materials

    International Nuclear Information System (INIS)

    Isobaev, M.D.; Davlatnazarova, M.D.; Abdullaev, T.H.

    2016-01-01

    The results showed the possibility of obtaining effective adsorbents of walnut shell and the sunflower for environmental purposes, in particular for the purification of polluted waters from heavy metals. It has been shown, that 1 g of walnut shell adsorbent can adsorb on its surface ions of lead in amount of 47% by weight. The dependence of the adsorption activity of the semi-coke received from walnut shell from particle size and concentration of the solution. (author)

  7. Fiber Based Mid Infrared Supercontinuum Source for Spectroscopic Analysis in Food Production

    DEFF Research Database (Denmark)

    Ramsay, Jacob; Dupont, Sune Vestergaard Lund; Keiding, Søren Rud

    Optimization of sustainable food production is a worldwide challenge that is undergoing continuous development as new technologies emerge. Applying solutions for food analysis with novel bright and broad mid-infrared (MIR) light sources has the potential to meet the increasing demands for food...

  8. Fiber-Based, Injection-Molded Optofluidic Systems: Improvements in Assembly and Applications

    Directory of Open Access Journals (Sweden)

    Marco Matteucci

    2015-12-01

    Full Text Available We present a method to fabricate polymer optofluidic systems by means of injection molding that allow the insertion of standard optical fibers. The chip fabrication and assembly methods produce large numbers of robust optofluidic systems that can be easily assembled and disposed of, yet allow precise optical alignment and improve delivery of optical power. Using a multi-level chip fabrication process, complex channel designs with extremely vertical sidewalls, and dimensions that range from few tens of nanometers to hundreds of microns can be obtained. The technology has been used to align optical fibers in a quick and precise manner, with a lateral alignment accuracy of 2.7 ± 1.8 μm. We report the production, assembly methods, and the characterization of the resulting injection-molded chips for Lab-on-Chip (LoC applications. We demonstrate the versatility of this technology by carrying out two types of experiments that benefit from the improved optical system: optical stretching of red blood cells (RBCs and Raman spectroscopy of a solution loaded into a hollow core fiber. The advantages offered by the presented technology are intended to encourage the use of LoC technology for commercialization and educational purposes.

  9. WGS-Adsorbent Reaction Studies at Laboratory Scale

    International Nuclear Information System (INIS)

    Marano, M.; Torreiro, Y.

    2014-01-01

    This document reports the most significant results obtained during the experimental work performed under task WGS adsorbent experimental studies within CAPHIGAS project (National Research Plan 2008-2011, ref: ENE2009-08002). The behavior of the binary adsorbent-catalyst system which will be used in the hybrid system is described in this document. Main results reported here were used during the design and development of the hybrid system adsorbent catalyst- membrane proposed in the CAPHIGAS project. The influence of main operating parameters and the optimized volume ratio adsorbent-catalyst are also presented in this report. (Author)

  10. Neutralization of Rubidium Adsorbate Electric Fields by Electron Attachment

    Energy Technology Data Exchange (ETDEWEB)

    Sedlacek, J. A. [Univ. of Oklahoma, Norman, OK (United States); Kim, E. [Univ. of Nevada, Las Vegas, NV (United States); Rittenhouse, S. T. [Western Washington Univ., Bellingham, WA (United States); US Naval Academy, Annapolis, MD (United States); Weck, Philippe F [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sadeghpour, H. R. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Shaffer, J. P. [Univ. of Oklahoma, Norman, OK (United States)

    2015-10-01

    We investigate the (0001) surface of single crystal quartz with a submonolayer of Rb adsorbates. Using Rydberg atom electromagnetically induced transparency, we investigate the electric elds resulting from Rb adsorbed on the quartz surface, and measure the activation energy of the Rb adsorbates. We show that the Rb induces a negative electron affnity (NEA) on the quartz surface. The NEA surface allows for low energy electrons to bind to the surface and cancel the electric eld from the Rb adsorbates. Our results have implications for integrating Rydberg atoms into hybrid quantum systems and the fundamental study of atom-surface interactions, as well as applications for electrons bound to a 2D surface.

  11. Theoretical Insight of Physical Adsorption for a Single-Component Adsorbent + Adsorbate System: I. Thermodynamic Property Surfaces

    KAUST Repository

    Chakraborty, Anutosh

    2009-02-17

    Thermodynamic property surfaces for a single-component adsorbent + adsorbate system are derived and developed from the viewpoint of classical thermodynamics, thermodynamic requirements of chemical equilibrium, Gibbs law, and Maxwell relations. They enable us to compute the entropy and enthalpy of the adsorbed phase, the isosteric heat of adsorption, specific heat capacity, and the adsorbed phase volume thoroughly. These equations are very simple and easy to handle for calculating the energetic performances of any adsorption system. We have shown here that the derived thermodynamic formulations fill up the information gap with respect to the state of adsorbed phase to dispel the confusion as to what is the actual state of the adsorbed phase. We have also discussed and established the temperature-entropy diagrams of (i) CaCl 2-in-silica gel + water system for cooling applications, and (ii) activated carbon (Maxsorb III) + methane system for gas storage. © Copyright 2009 American Chemical Society.

  12. Breakthrough indicator for aromatic VOCs using needle trap samplers for activated carbon adsorbent.

    Science.gov (United States)

    Cheng, Wen-Hsi; Jiang, Jia-Rong; Huang, Yi-Ning; Huang, Shiun-Chian; Yu, Yan-Pin

    2012-08-01

    Internal circulation cabinets equipped with granular activated carbon (GAC) for adsorbing volatile organic compounds (VOCs) are widely used to store bottles containing organic solvents in universities, colleges, and hospital laboratories throughout Taiwan. This work evaluates the VOC adsorption capacities of GAC using various adsorption times for gas stream mixtures of 100 ppm toluene and 100 ppm o-xylene. Additionally, needle trap sampling (NTS) technology was used to indicate the time for renewing the GAC to avoid VOC breakthrough from adsorbents. Experimental results demonstrate that the proposed models can linearly express toluene and o-xylene adsorption capacities as the natural logarithm of adsorption time (ln(t)) and can accurately simulate the equilibrium adsorption capacities (Qe, g VOCs/g GAC) for gaseous toluene and o-xylene. The NTS, packed with 60-80 mesh divinylbenzene (DVB) particles, was compared in terms of extraction efficiency by simultaneously using the 75-microm Carboxen/polydimethylsiloxane-solid-phase microextraction (Carboxen/PDMS-SPME) fiber for time-weighted average (TWA) sampling, and experimental results indicated that the packed DVB-NTS achieved higher toluene extraction rates. Additionally, the NTS installed in the outlet air stream for adsorbing toluene and o-xylene exhausted through GAC accurately indicated toluene and o-xylene breakthrough times of 4700-5000 min. The GAC-NTS operational instructions to indicate the replacing time of adsorbent in the internal circulation cabinets are also included in this paper.

  13. Heat capacity measurements of atoms and molecules adsorbed on evaporated metal films

    International Nuclear Information System (INIS)

    Kenny, T.W.

    1989-05-01

    Investigations of the properties of absorbed monolayers have received great experimental and theoretical attention recently, both because of the importance of surface processes in practical applications such as catalysis, and the importance of such systems to the understanding of the fundamentals of thermodynamics in two dimensions. We have adapted the composite bolometer technology to the construction of microcalorimeters. For these calorimeters, the adsorption substrate is an evaporated film deposited on one surface of an optically polished sapphire wafer. This approach has allowed us to make the first measurements of the heat capacity of submonolayer films of 4 He adsorbed on metallic films. In contrast to measurements of 4 He adsorbed on all other insulating substrates, we have shown that 4 He on silver films occupies a two-dimensional gas phase over a broad range of coverages and temperatures. Our apparatus has been used to study the heat capacity of Indium flakes. CO multilayers, 4 He adsorbed on sapphire and on Ag films and H 2 adsorbed on Ag films. The results are compared with appropriate theories. 68 refs., 19 figs

  14. Valuing Metal-Organic Frameworks for Postcombustion Carbon Capture: A Benchmark Study for Evaluating Physical Adsorbents

    KAUST Repository

    Adil, Karim

    2017-08-22

    The development of practical solutions for the energy-efficient capture of carbon dioxide is of prime importance and continues to attract intensive research interest. Conceivably, the implementation of adsorption-based processes using different cycling modes, e.g., pressure-swing adsorption or temperature-swing adsorption, offers great prospects to address this challenge. Practically, the successful deployment of practical adsorption-based technologies depends on the development of made-to-order adsorbents expressing mutually two compulsory requisites: i) high selectivity/affinity for CO2 and ii) excellent chemical stability in the presence of impurities. This study presents a new comprehensive experimental protocol apposite for assessing the prospects of a given physical adsorbent for carbon capture under flue gas stream conditions. The protocol permits: i) the baseline performance of commercial adsorbents such as zeolite 13X, activated carbon versus liquid amine scrubbing to be ascertained, and ii) a standardized evaluation of the best reported metal-organic framework (MOF) materials for carbon dioxide capture from flue gas to be undertaken. This extensive study corroborates the exceptional CO2 capture performance of the recently isolated second-generation fluorinated MOF material, NbOFFIVE-1-Ni, concomitant with an impressive chemical stability and a low energy for regeneration. Essentially, the NbOFFIVE-1-Ni adsorbent presents the best compromise by satisfying all the required metrics for efficient CO2 scrubbing.

  15. Ion exchange/adsorbent pilot plant

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    A decontamination of greater than 99% of the actinides and fission products contained in radioactive waste water can be obtained using ion exchange resins. A system for achieving this result is described in this paper. This ion exchange pilot-plant design is the culmination of five years of study of the decontamination of radioactive waste streams by ion exchange resins and other adsorbents at Mound. In order to maintain maximum flexibility of treatments, this pilot-plant design is a conceptual design with specific flows, resins, and column specifications, but with many optional features and no rigid equipment specifications. This flexibility allows the system to be amenable to almost any radioactive waste stream. Very specific designs can be constructed from this conceptual design for the treatment of any specific waste stream. Operating and capital costs are also discussed. 1 figure, 5 tables

  16. Canyon solvent cleaning with solid adsorbents

    International Nuclear Information System (INIS)

    Reif, D.J.

    1987-01-01

    The HM Process at the Savannah River Plant (SRP) uses 7.5% tributyl phosphate in n-paraffin as an extraction solvent. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials that influence product losses, product decontamination, and separation efficiencies. Laboratory studies to improve online solvent cleaning have shown that carbonate washing, although removing residual solvent activity, does not remove binding ligands that hold fission products in the solvent. Treatment of solvent with a solid adsorbent removes binding ligands and significantly improves recycle solvent performance. Both laboratory work defining a full-scale adsorption process and the use of the process to clean HM Process first cycle solvent are presented

  17. The condensation of water on adsorbed viruses.

    Science.gov (United States)

    Alonso, José María; Tatti, Francesco; Chuvilin, Andrey; Mam, Keriya; Ondarçuhu, Thierry; Bittner, Alexander M

    2013-11-26

    The wetting and dewetting behavior of biological nanostructures and to a greater degree single molecules is not well-known even though their contact with water is the basis for all biology. Here, we show that environmental electron microscopy (EM) can be applied as a means of imaging the condensation of water onto viruses. We captured the formation of submicrometer water droplets and filaments on single viral particles by environmental EM and by environmental transmission EM. The condensate structures are compatible with capillary condensation between adsorbed virus particles and with known droplet shapes on patterned surfaces. Our results confirm that such droplets exist down to condensation/evaporation cycle as expected from their stability in air and water. Moreover we developed procedures that overcome problems of beam damage and of resolving structures with a low atomic number.

  18. Applications of core level spectroscopy to adsorbates

    International Nuclear Information System (INIS)

    Nilsson, Anders

    2002-01-01

    In the following review different applications of core-level spectroscopy to atomic and molecular adsorbates will be shown. Core-holes are created through core-level ionization and X-ray absorption processes and the core-hole decays by radiant and non-radiant processes. This forms the basis for X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, Auger electron spectroscopy and X-ray emission spectroscopy. We will demonstrate how we can use the different methods to obtain information about the chemical state, local geometric structure, nature of chemical bonding and dynamics in electron transfer processes. The adsorption of N 2 and CO on Ni(100) will be used as prototype systems for chemisorption while N 2 on graphite and Ar on Pt for physisorption

  19. In vitro hydroxyapatite adsorbed salivary proteins

    International Nuclear Information System (INIS)

    Vitorino, Rui; Lobo, Maria Joao C.; Duarte, Jose; Ferrer-Correia, Antonio J.; Tomer, Kenneth B.; Dubin, Joshua R.; Domingues, Pedro M.; Amado, Francisco M.L.

    2004-01-01

    In spite of the present knowledge about saliva components and their respective functions, the mechanism(s) of pellicle and dental plaque formation have hitherto remained obscure. This has prompted recent efforts on in vitro studies using hydroxyapatite (HA) as an enamel model. In the present study salivary proteins adsorbed to HA were extracted with TFA and EDTA and resolved by 2D electrophoresis over a pH range between 3 and 10, digested, and then analysed by MALDI-TOF/TOF mass spectrometry and tandem mass spectrometry. Nineteen different proteins were identified using automated MS and MS/MS data acquisition. Among them, cystatins, amylase, carbonic anhydrase, and calgranulin B, were identified

  20. Biodegradation of bacterial polysaccharides adsorbed on montmorillonite

    International Nuclear Information System (INIS)

    Guckert, A.; Tok, H.H.; Jacquin, F.

    1977-01-01

    In this research, by means of a model, a study was made of the biodegradation of microbial organic compounds adsorbed on clays, with a parallel experiment on Fontainebleau sand serving as the control. During incubation the three classes of organic matter ( 14 C-labelled glucose, 14 C-labelled polysaccharides and 14 C-labelled microbial cells) mineralize more actively in the presence of sand than in the presence of clay, since the latter provides protection against biodegradation. Mineralization of the adsorbed organic compounds, however, is marked by clear-cut differences after three weeks - glucose (55%)>polysaccharides (43%)>microbial organisms (7.3%). After incubation, chemical extraction of the organo-mineral complexes by alkaline solvents shows only water-soluble and alkali-soluble products in the case of sand; conversely, in that of montmorillonite the bulk of the 14 C was found in the non-extractable fraction or humin (18.1% of the initial 14 C for glucose, 27.3% for the polysaccharides, and 67.6% for the microbial organisms). A second incubation carried out after a phase in which there was drying and remoistening of the organo-mineral complexes, brings to light the important part played by climatic alternations during the biodegradation process. A new mineralization phase is observed, affecting more the bacterial organisms (14.1%) than the polysaccharides (6.3%), with the glucose-base complexes occupying an intermediate position (11.2%). The chemical fractioning of the organo-mineral complexes following re-incubation shows the stability of 14 C in humin very clearly, especially in the case of polysaccharides, where the mineralization phase relates primarily to the products extractable with alkalis. (author)

  1. Fiber based optical tweezers for simultaneous in situ force exertion and measurements in a 3D polyacrylamide gel compartment.

    Science.gov (United States)

    Ti, Chaoyang; Thomas, Gawain M; Ren, Yundong; Zhang, Rui; Wen, Qi; Liu, Yuxiang

    2015-07-01

    Optical tweezers play an important role in biological applications. However, it is difficult for traditional optical tweezers based on objective lenses to work in a three-dimensional (3D) solid far away from the substrate. In this work, we develop a fiber based optical trapping system, namely inclined dual fiber optical tweezers, that can simultaneously apply and measure forces both in water and in a 3D polyacrylamide gel matrix. In addition, we demonstrate in situ, non-invasive characterization of local mechanical properties of polyacrylamide gel by measurements on an embedded bead. The fiber optical tweezers measurements agree well with those of atomic force microscopy (AFM). The inclined dual fiber optical tweezers provide a promising and versatile tool for cell mechanics study in 3D environments.

  2. Development of photonic-crystal-fiber-based optical coupler with a broad operating wavelength range of 800 nm

    International Nuclear Information System (INIS)

    Yoon, Min-Seok; Kwon, Oh-Jang; Kim, Hyun-Joo; Chu, Su-Ho; Kim, Gil-Hwan; Lee, Sang-Bae; Han, Young-Geun

    2010-01-01

    We developed a broadband optical coupler based on a photonic crystal fiber (PCF), which is very useful for applications to optical coherence tomography (OCT). The PCF-based coupler is fabricated by using a fused biconical tapering (FBT) method. The PCF has six hexagonally-stacked layers of air holes. The PCF-based coupler has a nearly-flat 50/50 coupling ratio in a broad bandwidth range of 800 nm, which is much wider than that previously reported for a PCF-based coupler and a singlemode-fiber-based coupler. The bandwidth and the bandedge wavelength of the broadband coupler are controlled by changing the elongation length. The fabricated broadband optical coupler has great potential for realizing a broadband interferogram with a high resolution in an OCT system.

  3. Understanding Trends in Catalytic Activity: The Effect of Adsorbate-Adsorbate Interactions for CO Oxidation Over Transition Metals

    DEFF Research Database (Denmark)

    Grabow, Lars; Larsen, Britt Hvolbæk; Nørskov, Jens Kehlet

    2010-01-01

    Using high temperature CO oxidation as the example, trends in the reactivity of transition metals are discussed on the basis of density functional theory (DFT) calculations. Volcano type relations between the catalytic rate and adsorption energies of important intermediates are introduced...... and the effect of adsorbate-adsorbate interaction on the trends is discussed. We find that adsorbate-adsorbate interactions significantly increase the activity of strong binding metals (left side of the volcano) but the interactions do not change the relative activity of different metals and have a very small...... influence on the position of the top of the volcano, that is, on which metal is the best catalyst....

  4. A nuclear standard high-efficiency adsorber for iodine

    International Nuclear Information System (INIS)

    Wang Jianmin; Qian Yinge

    1988-08-01

    The structure of a nuclear standard high-efficiency adsorber, adsorbent and its performance are introduced. The performance and structure were compared with the same kind product of other firms. The results show that the leakage rate is less than 0.005%

  5. Comparative evaluation of selected starches as adsorbent for Thin ...

    African Journals Online (AJOL)

    The most commonly used is silica gel which is an inorganic adsorbent. Organic substances like cellulose, polyethylene are also used. All these are imported into Nigeria and are unhealthy for economic policies. Most commonly used adsorbent may not be easy to produce locally, but starch, which is a very common product, ...

  6. Synthesis and properties of porous zeolite aluminosilicate adsorbents

    International Nuclear Information System (INIS)

    Shilina, A.S.; Milinchuk, V.K.; Burukhin, S.B.; Gordienko, A.B.

    2015-01-01

    Environmentally safe non-energy-intensive methods of the synthesis have been developed and the properties of solid inorganic nanostructured zeolite-like adsorbents of a broad spectrum have been studied. The sorption capacities of the adsorbents with respect to various components of water pollution have been determined [ru

  7. Development of ultrafiltration and inorganic adsorbents: January--March 1977

    International Nuclear Information System (INIS)

    Koenst, J.W. Jr.

    1977-01-01

    Ultrafiltration media with and without the assistance of bone char filters were evaluated to determine their effectiveness in removing radionuclides from contaminated solutions. Precipitants, resin, adsorbents, and inorganic adsorbents were studied to determine their effectiveness in decontaminating solutions. A study of the effects of radiation on ultrafiltration media was initiated. An ultrafiltration media pilot plant was ordered and is being installed

  8. Friction and diffusion dynamics of adsorbates at surfaces

    NARCIS (Netherlands)

    Fusco, C.

    2005-01-01

    A theoretical study of the motion of adsorbates (e. g. atoms, molecules or clusters) on solid surfaces is presented, with a focus on surface diffusion and atomic-scale friction. These two phenomena are inextricably linked, because when an atomic or molecular adsorbate diffuses, or is pulled, it

  9. Mixed-matrix membrane adsorbers for protein separation

    NARCIS (Netherlands)

    Avramescu, M.E.; Borneman, Z.; Wessling, M.

    2003-01-01

    The separation of two similarly sized proteins, bovine serum albumin (BSA) and bovine hemoglobin (Hb) was carried out using a new type of ion-exchange mixed-matrix adsorber membranes. The adsorber membranes were prepared by incorporation of various types of Lewatit ion-exchange resins into an

  10. Ionogenic adsorbents based on local raw materials for radiation protection

    International Nuclear Information System (INIS)

    Isobaev, M.D.; Davlatnazarova, M.; Turdialiev, M.Z.; Abdullayev, T.H.; Pulatov, E.H.

    2012-01-01

    The successful management of uranium wastes and creating the conditions for effective rehabilitation activities require special adsorbents capable of holding on the surface complexes, including radioactive elements. Currently tested and have shown promising synthetic adsorbents based pitted apricot fruits and other fruit plants. This report presents data for the establishment of ionic type available adsorbents based on Tajikistan coal. As the base for the creation of this type of adsorbent were taken the coal of the 'Ziddi' deposits. As follows from our data on the chemical composition, the studied coals contain more than 20% of the ash. According to the available literature theses ashes contains various minerals compositions that can form the adsorbent's active surface. Thus, the model for this type of activated carbon can serve as a mixture of zeolite, ion exchange resins and activated carbon itself.

  11. Processing method and device for iodine adsorbing material

    International Nuclear Information System (INIS)

    Watanabe, Shin-ichi; Shiga, Reiko.

    1997-01-01

    An iodine adsorbing material adsorbing silver compounds is reacted with a reducing gas, so that the silver compounds are converted to metal silver and stored. Then, the silver compounds are not melted or recrystallized even under a highly humid condition, accordingly, peeling of the adsorbed materials from a carrier can be prevented, and the iodine adsorbing material can be stored stably. Since the device is disposed in an off gas line for discharging off gases from a nuclear power facility, the iodine adsorbing material formed by depositing silver halides to the carrier is contained, and a reducing or oxidizing gas is supplied to the vessel as required, and silver halides can be converted to metal silver or the metal silver can be returned to silver halide. (T.M.)

  12. Nano-sized Adsorbate Structure Formation in Anisotropic Multilayer System

    Science.gov (United States)

    Kharchenko, Vasyl O.; Kharchenko, Dmitrii O.; Yanovsky, Vladimir V.

    2017-05-01

    In this article, we study dynamics of adsorbate island formation in a model plasma-condensate system numerically. We derive the generalized reaction-diffusion model for adsorptive multilayer system by taking into account anisotropy in transfer of adatoms between neighbor layers induced by electric field. It will be found that with an increase in the electric field strength, a structural transformation from nano-holes inside adsorbate matrix toward separated nano-sized adsorbate islands on a substrate is realized. Dynamics of adsorbate island sizes and corresponding distributions are analyzed in detail. This study provides an insight into details of self-organization of adatoms into nano-sized adsorbate islands in anisotropic multilayer plasma-condensate systems.

  13. Noble gas separation with the use of inorganic adsorbents

    International Nuclear Information System (INIS)

    Pence, D.T.; Chou, C.C.; Christian, J.D.; Paplawsky, W.J.

    1979-01-01

    A noble gas separation process is proposed for application to airborne nuclear fuel reprocessing plant effluents. The process involves the use of inorganic adsorbents for the removal of contaminant gases and noble gas separation through selective adsorption. Water and carbon dioxide are removed with selected zeolites that do not appreciably adsorb the noble gases. Xenon is essentially quantitatively removed with a specially developed adsorbent using conventional adsorption-desorption techniques. Oxygen is removed to low ppM levels by the use of a rapid cycle adsorption technique on a special adsorbent leaving a krypton-nitrogen mixture. Krypton is separated from nitrogen with a special adsorbent operated at about -80 0 C. Because the separation process does not require high pressures and oxygen is readily removed to sufficiently limit ozone formation to insignificant levels, appreciable capital and operating cost savings with this process are possible compared with other proposed processes. In addition, the proposed process is safer to operate

  14. Flow boundary conditions for chain-end adsorbing polymer blends.

    Science.gov (United States)

    Zhou, Xin; Andrienko, Denis; Delle Site, Luigi; Kremer, Kurt

    2005-09-08

    Using the phenol-terminated polycarbonate blend as an example, we demonstrate that the hydrodynamic boundary conditions for a flow of an adsorbing polymer melt are extremely sensitive to the structure of the epitaxial layer. Under shear, the adsorbed parts (chain ends) of the polymer melt move along the equipotential lines of the surface potential whereas the adsorbed additives serve as the surface defects. In response to the increase of the number of the adsorbed additives the surface layer becomes thinner and solidifies. This results in a gradual transition from the slip to the no-slip boundary condition for the melt flow, with a nonmonotonic dependence of the slip length on the surface concentration of the adsorbed ends.

  15. Efficiency of moso bamboo charcoal and activated carbon for adsorbing radioactive iodine

    Energy Technology Data Exchange (ETDEWEB)

    Chien, Chuan-Chi; Huang, Ying-Pin; Wang, Wie-Chieh [ITRI South, Industrial Technology Research Institute, Tainan (China); Chao, Jun-Hsing; Wei, Yuan-Yao [Nuclear Science and Technology Development Center, National Tsing Hua University, Hsinchu (China)

    2011-02-15

    Preventing radioactive pollution is a troublesome problem but an urgent concern worldwide because radioactive substances cause serious health-related hazards to human being. The adsorption method has been used for many years to concentrate and remove radioactive pollutants; selecting an adequate adsorbent is the key to the success of an adsorption-based pollution abatement system. In Taiwan, all nuclear power plants use activated carbon as the adsorbent to treat radiation-contaminated air emission. The activated carbon is entirely imported; its price and manufacturing technology are entirely controlled by international companies. Taiwan is rich in bamboo, which is one of the raw materials for high-quality activated carbon. Thus, a less costly activated carbon with the same or even better adsorptive capability as the imported adsorbent can be made from bamboo. The objective of this research is to confirm the adsorptive characteristics and efficiency of the activated carbon made of Taiwan native bamboo for removing {sup 131}I gas from air in the laboratory. The study was conducted using new activated carbon module assembled for treating {sup 131}I-contaminated air. The laboratory results reveal that the {sup 131}I removal efficiency for a single-pass module is as high as 70%, and the overall efficiency is 100% for four single-pass modules operated in series. The bamboo charcoal and bamboo activated carbon have suitable functional groups for adsorbing {sup 131}I and they have greater adsorption capacities than commercial activated carbons. Main mechanism is for trapping of radioiodine on impregnated charcoal, as a result of surface oxidation. When volatile radioiodine is trapped by potassium iodide-impregnated bamboo charcoal, the iodo-compound is first adsorbed on the charcoal surface, and then migrates to iodide ion sites where isotope exchange occurs. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Bioavailability of Carbon Nanomaterial-Adsorbed Polycyclic Aromatic Hydrocarbons to Pimphales promelas: Influence of Adsorbate Molecular Size and Configuration.

    Science.gov (United States)

    Linard, Erica N; Apul, Onur G; Karanfil, Tanju; van den Hurk, Peter; Klaine, Stephen J

    2017-08-15

    Despite carbon nanomaterials' (CNMs) potential to alter the bioavailability of adsorbed contaminants, information characterizing the relationship between adsorption behavior and bioavailability of CNM-adsorbed contaminants is still limited. To investigate the influence of CNM morphology and organic contaminant (OC) physicochemical properties on this relationship, adsorption isotherms were generated for a suite of polycyclic aromatic hydrocarbons (PAHs) on multiwalled carbon nanotubes (MWCNTs) and exfoliated graphene (GN) in conjunction with determining the bioavailability of the adsorbed PAHs to Pimphales promelas using bile analysis via fluorescence spectroscopy. Although it appeared that GN adsorbed PAHs indiscriminately compared to MWCNTs, the subsequent bioavailability of GN-adsorbed PAHs was more sensitive to PAH morphology than MWCNTs. GN was effective at reducing bioavailability of linear PAHs by ∼70%, but had little impact on angular PAHs. MWCNTs were sensitive to molecular size, where bioavailability of two-ringed naphthalene was reduced by ∼80%, while bioavailability of the larger PAHs was reduced by less than 50%. Furthermore, the reduction in bioavailability of CNM-adsorbed PAHs was negatively correlated with the amount of CNM surface area covered by the adsorbed-PAHs. This study shows that the variability in bioavailability of CNM-adsorbed PAHs is largely driven by PAH size, configuration and surface area coverage.

  17. Milestone Report - Complete New Adsorbent Materials for Marine Testing to Demonstrate 4.5 g-U/kg Adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Janke, Christopher James [ORNL; Das, Sadananda [ORNL; Oyola, Yatsandra [ORNL; Mayes, Richard T. [ORNL; Saito, Tomonori [ORNL; Brown, Suree [ORNL; Gill, Gary [PNNL; Kuo, Li-Jung [PNNL; Wood, Jordana [PNNL

    2014-08-01

    This report describes work on the successful completion of Milestone M2FT-14OR03100115 (8/20/2014) entitled, “Complete new adsorbent materials for marine testing to demonstrate 4.5 g-U/kg adsorbent”. This effort is part of the Seawater Uranium Recovery Program, sponsored by the U.S. Department of Energy, Office of Nuclear Energy, and involved the development of new adsorbent materials at the Oak Ridge National Laboratory (ORNL) and marine testing at the Pacific Northwest National Laboratory (PNNL). ORNL has recently developed two new families of fiber adsorbents that have demonstrated uranium adsorption capacities greater than 4.5 g-U/kg adsorbent after marine testing at PNNL. One adsorbent was synthesized by radiation-induced graft polymerization of itaconic acid and acrylonitrile onto high surface area polyethylene fibers followed by amidoximation and base conditioning. This fiber showed a capacity of 4.6 g-U/kg adsorbent in marine testing at PNNL. The second adsorbent was prepared by atom-transfer radical polymerization of t-butyl acrylate and acrylonitrile onto halide-functionalized round fibers followed by amidoximation and base hydrolysis. This fiber demonstrated uranium adsorption capacity of 5.4 g-U/kg adsorbent in marine testing at PNNL.

  18. Testing and evaluation of a slot and tab construction technique for light-weight wood-fiber-based structural panels under bending

    Science.gov (United States)

    Jinghao Li; John F. Hunt; Shaoqin Gong; Zhiyong Cai

    2015-01-01

    This paper presented construction and strain distributions for light-weight wood-fiber-based structural panels with tri-grid core made from phenolic impregnated laminated paper composites under bending. A new fastening configuration of slots in the faces and tabs on the core was applied to the face/core interfaces of the sandwich panel in addition to epoxy resin. Both...

  19. Investigation on the fiber based approach to estimate the axial load carrying capacity of the circular concrete filled steel tube (CFST)

    Science.gov (United States)

    Piscesa, B.; Attard, M. M.; Suprobo, P.; Samani, A. K.

    2017-11-01

    External confining devices are often used to enhance the strength and ductility of reinforced concrete columns. Among the available external confining devices, steel tube is one of the most widely used in construction. However, steel tube has some drawbacks such as local buckling which needs to be considered when estimating the axial load carrying capacity of the concrete-filled-steel-tube (CFST) column. To tackle this problem in design, Eurocode 4 provided guidelines to estimate the effective yield strength of the steel tube material. To study the behavior of CFST column, in this paper, a non-linear analysis using a fiber-based approach was conducted. The use of the fiber-based approach allows the engineers to predict not only the axial load carrying capacity but also the complete load-deformation curve of the CFST columns for a known confining pressure. In the proposed fiber-based approach, an inverse analysis is used to estimate the constant confining pressure similar to design-oriented models. This paper also presents comparisons between the fiber-based approach model with the experimental results and the 3D non-linear finite element analysis.

  20. Surface characterization of Ag/Titania adsorbents

    International Nuclear Information System (INIS)

    Samokhvalov, Alexander; Nair, Sachin; Duin, Evert C.; Tatarchuk, Bruce J.

    2010-01-01

    The Ag/Titania adsorbent for selective removal of the desulfurization-refractive polycyclic aromatic sulfur heterocycles (PASHs) from liquid hydrocarbon fuels was prepared, its total and the Ag specific surface area were determined and the surface reaction sites in the sorbent that may be active in the adsorptive selective desulfurization were characterized by several spectroscopic and surface science techniques. The sorbent contains Ag, Ti, O and spurious C on its surface, as by the XPS measurements. Silver is present as an oxide, as judged by the XPS Auger parameter (AP). The complementary electron spin resonance (ESR) spectroscopy confirms that the majority of Ag is present in the diamagnetic Ag 1+ form, with the minor concentration (∼0.1% of total Ag) present as Ag 2+ . The findings by XPS and ESR are confirmed by the XRD, UV-vis spectroscopy and thermodynamic considerations. The supported Ag is highly dispersed on the surface of the titania support, with the particle size of ∼30-60 A depending on Ag content, with an Ag specific surface area of ∼7-14 m 2 /g, vs. the total surface area of ∼114-58 m 2 /g.

  1. Strain transfer analysis of optical fiber based sensors embedded in an asphalt pavement structure

    International Nuclear Information System (INIS)

    Wang, Huaping; Xiang, Ping

    2016-01-01

    Asphalt pavement is vulnerable to random damage, such as cracking and rutting, which can be proactively identified by distributed optical fiber sensing technology. However, due to the material nature of optical fibers, a bare fiber is apt to be damaged during the construction process of pavements. Thus, a protective layer is needed for this application. Unfortunately, part of the strain of the host material is absorbed by the protective layer when transferring the strain to the sensing fiber. To account for the strain transfer error, in this paper a theoretical analysis of the strain transfer of a three-layered general model has been carried out by introducing Goodman’s hypothesis to describe the interfacial shear stress relationship. The model considers the viscoelastic behavior of the host material and protective layer. The effects of one crack in the host material and the sensing length on strain transfer relationship are been discussed. To validate the effectiveness of the strain transfer analysis, a flexible asphalt-mastic packaged distributed optical fiber sensor was designed and tested in a laboratory environment to monitor the distributed strain and appearance of cracks in an asphalt concrete beam at two different temperatures. The experimental results indicated that the developed strain transfer formula can significantly reduce the strain transfer error, and that the asphalt-mastic packaged optical fiber sensor can successfully monitor the distributed strain and identify local cracks. (paper)

  2. Experimental study on distributed optical fiber-based approach monitoring saturation line in levee engineering

    Science.gov (United States)

    Su, Huaizhi; Li, Hao; Kang, Yeyuan; Wen, Zhiping

    2018-02-01

    Seepage is one of key factors which affect the levee engineering safety. The seepage danger without timely detection and rapid response may likely lead to severe accidents such as seepage failure, slope instability, and even levee break. More than 90 percent of levee break events are caused by the seepage. It is very important for seepage behavior identification to determine accurately saturation line in levee engineering. Furthermore, the location of saturation line has a major impact on slope stability in levee engineering. Considering the structure characteristics and service condition of levee engineering, the distributed optical fiber sensing technology is introduced to implement the real-time observation of saturation line in levee engineering. The distributed optical fiber temperature sensor system (DTS)-based monitoring principle of saturation line in levee engineering is investigated. An experimental platform, which consists of DTS, heating system, water-supply system, auxiliary analysis system and levee model, is designed and constructed. The monitoring experiment of saturation line in levee model is implemented on this platform. According to the experimental results, the numerical relationship between moisture content and thermal conductivity in porous medium is identified. A line heat source-based distributed optical fiber method obtaining the thermal conductivity in porous medium is developed. A DTS-based approach is proposed to monitor the saturation line in levee engineering. The embedment pattern of optical fiber for monitoring saturation line is presented.

  3. Fiber-Based, Double-Sided, Reduced Graphene Oxide Films for Efficient Solar Vapor Generation.

    Science.gov (United States)

    Guo, Ankang; Ming, Xin; Fu, Yang; Wang, Gang; Wang, Xianbao

    2017-09-06

    Solar vapor generation is a promising and whole new branch of photothermal conversion for harvesting solar energy. Various materials and devices for solar thermal conversion were successively produced and reported for higher solar energy utilization in the past few years. Herein, a compact device of reduced graphene oxides (rGO) and paper fibers was designed and assembled for efficient solar steam generation under light illumination, and it consists of water supply pipelines (WSP), a thermal insulator (TI) and a double-sided absorbing film (DSF). Heat localization is enabled by the black DSF due to its broad absorption of sunlight. More importantly, the heat transfer, from the hot DSF to the cold base fluid (water), was suppressed by TI with a low thermal conductivity. Meanwhile, bulk water was continuously transported to the DSF by WSP through TI, which was driven by the surface energy and surface tension based on the capillary effect. The effects of reduction degrees of rGO on the photothermal conversion were explored, and the evaporation efficiency reached 89.2% under one sun with 60 mg rGO. This new microdevice provided a basic technical support for distillation, desalination, sewage treatment, and related technologies.

  4. Strain transfer analysis of optical fiber based sensors embedded in an asphalt pavement structure

    Science.gov (United States)

    Wang, Huaping; Xiang, Ping

    2016-07-01

    Asphalt pavement is vulnerable to random damage, such as cracking and rutting, which can be proactively identified by distributed optical fiber sensing technology. However, due to the material nature of optical fibers, a bare fiber is apt to be damaged during the construction process of pavements. Thus, a protective layer is needed for this application. Unfortunately, part of the strain of the host material is absorbed by the protective layer when transferring the strain to the sensing fiber. To account for the strain transfer error, in this paper a theoretical analysis of the strain transfer of a three-layered general model has been carried out by introducing Goodman’s hypothesis to describe the interfacial shear stress relationship. The model considers the viscoelastic behavior of the host material and protective layer. The effects of one crack in the host material and the sensing length on strain transfer relationship are been discussed. To validate the effectiveness of the strain transfer analysis, a flexible asphalt-mastic packaged distributed optical fiber sensor was designed and tested in a laboratory environment to monitor the distributed strain and appearance of cracks in an asphalt concrete beam at two different temperatures. The experimental results indicated that the developed strain transfer formula can significantly reduce the strain transfer error, and that the asphalt-mastic packaged optical fiber sensor can successfully monitor the distributed strain and identify local cracks.

  5. Novel fiber-based pure chitosan scaffold for tendon augmentation: biomechanical and cell biological evaluation.

    Science.gov (United States)

    Nowotny, J; Aibibu, D; Farack, J; Nimtschke, U; Hild, M; Gelinsky, M; Kasten, P; Cherif, Ch

    2016-07-01

    One possibility to improve the mechanical properties after tendon ruptures is augmentation with a scaffold. Based on wet spinning technology, chitosan fibres were processed to a novel pure high-grade multifilament yarn with reproducible quality. The fibres were braided to obtain a 3D tendon scaffold. The CS fibres and scaffolds were evaluated biomechanically and compared to human supraspinatus (SSP) tendons. For the cytobiological characterization, in vitro cell culture experiments with human mesenchymal stem cells (hMSC) were performed. Three types of 3D circular braided scaffolds were fabricated. Significantly, higher ultimate stress values were measured for scaffold with larger filament yarn, compared to scaffold with smaller filament yarn. During cultivation over 28 days, the cells showed in dependence of isolation method and/or donor a doubling or tripling of the cell number or even a six-fold increase on the CS scaffold, which was comparable to the control (polystyrene) or in the case of cells obtained from human biceps tendon even higher proliferation rates. After 14 days, the scaffold surface was covered homogeneously with a cell layer. In summary, the present work demonstrates that braided chitosan scaffolds constitute a straightforward approach for designing tendon analogues, maintaining important flexibility in scaffold design and providing favourable mechanical properties of the resulting construct.

  6. Differences between tethered polyelectrolyte chains adsorbed onto bare mica and hydrophobically modified mica, comparison with theory.

    Science.gov (United States)

    Balastre, Marc; Tamashiro, Mario N.; Hernandez, Ernesto; Pincus, Philip; Tirrell, Matthew

    2001-03-01

    End-grafted polymers generated from the adsorption of asymmetric diblock copolymers on solid surface play an important role in many areas of science and technology. While the small insoluble block acts as an anchor, the charged soluble block confers useful properties to the surface. This study looks at tethered layers of poly(styrene sulfonate)/poly(t-butyl styrene) (PtBS-PSS) adsorbed on both mica (hydrophilic) and octadecyltriethoxysilane (OTE) modified mica (hydrophobic). Normal compressing forces at two different constant grafting densities (bare and modified mica) were measured with the surface force apparatus and compared with theoretical prediction. The effect of salt concentration (Cs) upon the thickness of the self-assembled layers (Lo) was measured in each case. For adsorption of diblock copolymers onto OTE the resulting scaling relationship is much closer to the brush theory, Lo Cs-1/3. This result suggests that the adsorbed amount on mica is not high enough to form a brush.

  7. Thermal enhancement of charge and discharge cycles for adsorbed natural gas storage

    KAUST Repository

    Rahman, Kazi Afzalur

    2011-07-01

    The usage of adsorbed natural gas (ANG) storage is hindered by the thermal management during the adsorption and desorption processes. An effective thermal enhancement is thus essential for the development of the ANG technology and the motivation for this study is the investigation of a gas storage system with internal thermal control. We employed a fin-tube type heat exchanger that is placed in a pressurized cylinder. A distributed-parameter model is used for the theoretical modeling and simulations are conducted at assorted charging and discharging conditions. These studies included the transient thermal behaviours of the elements within the ANG-charged cylinder and parameters such as pressure and temperature profiles of adsorbent have been obtained during charge and discharge cycles, and results are compared with a conventional compressed methane vessel. © 2011 Elsevier Ltd. All rights reserved.

  8. The molecular mechanism of mediation of adsorbed serum proteins to endothelial cells adhesion and growth on biomaterials.

    Science.gov (United States)

    Yang, Dayun; Lü, Xiaoying; Hong, Ying; Xi, Tingfei; Zhang, Deyuan

    2013-07-01

    To explore molecular mechanism of mediation of adsorbed proteins to cell adhesion and growth on biomaterials, this study examined endothelial cell adhesion, morphology and viability on bare and titanium nitride (TiN) coated nickel titanium (NiTi) alloys and chitosan film firstly, and then identified the type and amount of serum proteins adsorbed on the three surfaces by proteomic technology. Subsequently, the mediation role of the identified proteins to cell adhesion and growth was investigated with bioinformatics analyses, and further confirmed by a series of cellular and molecular biological experiments. Results showed that the type and amount of adsorbed serum proteins associated with cell adhesion and growth was obviously higher on the alloys than on the chitosan film, and these proteins mediated endothelial cell adhesion and growth on the alloys via four ways. First, proteins such as adiponectin in the adsorbed protein layer bound with cell surface receptors to generate signal transduction, which activated cell surface integrins through increasing intracellular calcium level. Another way, thrombospondin 1 in the adsorbed protein layer promoted TGF-β signaling pathway activation and enhanced integrins expression. The third, RGD sequence containing proteins such as fibronectin 1, vitronectin and thrombospondin 1 in the adsorbed protein layer bound with activated integrins to activate focal adhesion pathway, increased focal adhesion formation and actin cytoskeleton organization and mediated cell adhesion and spreading. In addition, the activated focal adhesion pathway promoted the expression of cell growth related genes and resulted in cell proliferation. The fourth route, coagulation factor II (F2) and fibronectin 1 in the adsorbed protein layer bound with cell surface F2 receptor and integrin, activated regulation of actin cytoskeleton pathway and regulated actin cytoskeleton organization. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Mercury adsorption properties of sulfur-impregnated adsorbents

    Science.gov (United States)

    Hsi, N.-C.; Rood, M.J.; Rostam-Abadi, M.; Chen, S.; Chang, R.

    2002-01-01

    Carbonaceous and noncarbonaceous adsorbents were impregnated with elemental sulfur to evaluate the chemical and physical properties of the adsorbents and their equilibrium mercury adsorption capacities. Simulated coal combustion flue gas conditions were used to determine the equilibrium adsorption capacities for Hg0 and HgCl2 gases to better understand how to remove mercury from gas streams generated by coal-fired utility power plants. Sulfur was deposited onto the adsorbents by monolayer surface deposition or volume pore filling. Sulfur impregnation increased the total sulfur content and decreased the total and micropore surface areas and pore volumes for all of the adsorbents tested. Adsorbents with sufficient amounts of active adsorption sites and sufficient microporous structure had mercury adsorption capacities up to 4,509 ??g Hg/g adsorbent. Elemental sulfur, organic sulfur, and sulfate were formed on the adsorbents during sulfur impregnation. Correlations were established with R2>0.92 between the equilibrium Hg0/HgCl2 adsorption capacities and the mass concentrations of elemental and organic sulfur. This result indicates that elemental and organic sulfur are important active adsorption sites for Hg0 and HgCl2.

  10. A theoretical study of adsorbate-adsorbate interactions on Ru(0001)

    DEFF Research Database (Denmark)

    Mortensen, Jens Jørgen; Hammer, Bjørk; Nørskov, Jens Kehlet

    1998-01-01

    the barrier for dissociation, whereas S will increase it. The interaction with alkali atoms is mainly of an electrostatic nature. The poisoning by S is due to two kinds of repulsive interactions: a Pauli repulsion and a reduced covalent bond strength between the adsorbate and the surface d-electrons. In order...... to investigate these different interactions in more detail, we look at three different species (N atoms, and terminally bonded N(2) and CO) and use them as probes to study their interaction with two modifier atoms (Na and S). The two modifier atoms have very different properties, which allows us to decouple...

  11. Scanning tunneling spectroscopy of Co adsorbates on superconducting Pb nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Decker, Regis; Caminale, Michael; Oka, Hirofumi; Stepniak, Agnieszka; Leon Vanegas, Augusto A.; Sander, Dirk; Kirschner, Juergen [Max-Planck-Institut fuer Mikrostrukturphysik, Weinberg 2, 06120 Halle (Germany)

    2015-07-01

    Superconductivity in low-dimensional structures has become an active research area. In order to understand the superconducting pairing, long-standing work has been devoted to the pair breaking effect, where magnetic impurities break Cooper pair singlets. We performed scanning tunneling spectroscopy at low temperature on Co adsorbates on superconducting Pb nanoislands. On the Co adsorbates, we observe spectral features in the superconductor's energy gap, which we attribute to magnetic impurity induced bound states, a hallmark of the pair breaking effect. We discuss the response of the superconducting islands to the presence of Co adsorbates.

  12. Technology.

    Science.gov (United States)

    Online-Offline, 1998

    1998-01-01

    Focuses on technology, on advances in such areas as aeronautics, electronics, physics, the space sciences, as well as computers and the attendant progress in medicine, robotics, and artificial intelligence. Describes educational resources for elementary and middle school students, including Web sites, CD-ROMs and software, videotapes, books,…

  13. Investigations to increase the efficiency of fluorine and boron removal from groundwater using radiation-induced graft polymerization adsorbent

    International Nuclear Information System (INIS)

    Iyatomi, Yosuke; Shimada, Akiomi; Ogata, Nobuhisa; Sugihara, Kozo; Hoshina, Hiroyuki; Seko, Noriaki; Kasai, Noboru; Ueki, Yuji; Tamada, Masao

    2010-01-01

    The Japan Atomic Energy Agency is performing a research project in the Mizunami Underground Research Laboratory (MIU) to build a firm scientific and technological basis for the studies of the deep underground environment in crystalline rock. In the project, it is necessary to reduce the fluorine and boron concentrations in groundwater pumped from the MIU shafts to levels below the environmental standards. This is done at the MIU water treatment facility using coagulation and ion exchange treatment for fluorine and boron, respectively. In addition, in 2006, research started on the efficient treatment of groundwater for removal of fluorine and boron using a radiation-induced graft polymerization adsorbent. The adsorbent removed boron at a flow rate (space velocity (SV)=120 h -1 ) higher than that of a general ion exchange resin (SV=10 h -1 ) and the adsorbent could be used repeatedly. It was also apparent that the pH of groundwater had an influence on adsorption performance. With respect to fluorine removal, more than 90% of fluorine was removed. However, the adsorbent for fluorine showed a lower adsorption capacity than that for boron. The reason for this difference is considered to be related to the initial concentration difference between fluorine and boron in the groundwater. Therefore, it is necessary to define the initial concentrations of dissolved materials, which can be used as better indicators of the performance of the adsorbent. (author)

  14. Dual-mode optical fiber-based tweezers for robust trapping and manipulation of absorbing particles in air

    Science.gov (United States)

    Sil, Souvik; Kanti Saha, Tushar; Kumar, Avinash; Bera, Sudipta K.; Banerjee, Ayan

    2017-12-01

    We develop an optical tweezers system using a single dual-mode optical fiber where mesoscopic absorbing particles can be trapped in three dimensions and manipulated employing photophoretic forces. We generate a superposition of fundamental and first order Hermite-Gaussian beam modes by the simple innovation of coupling a laser into a commercial optical fiber designed to be single mode for a wavelength higher than that of the laser. We achieve robust trapping of the absorbing particles for hours using both the pure fundamental and superposition mode beams and attain large manipulation velocities of ˜5 mm s-1 in the axial direction and ˜0.75 mm s-1 in the radial direction. We then demonstrate that the superposition mode is more effective in trapping and manipulation compared to the fundamental mode by around 80%, which may be increased several times by the use of a pure first order Hermite-Gaussian mode. The work has promising implications for trapping and spectroscopy of aerosols in air using simple optical fiber-based traps.

  15. Performance analysis for IEEE 802.11 distributed coordination function in radio-over-fiber-based distributed antenna systems.

    Science.gov (United States)

    Fan, Yuting; Li, Jianqiang; Xu, Kun; Chen, Hao; Lu, Xun; Dai, Yitang; Yin, Feifei; Ji, Yuefeng; Lin, Jintong

    2013-09-09

    In this paper, we analyze the performance of IEEE 802.11 distributed coordination function in simulcast radio-over-fiber-based distributed antenna systems (RoF-DASs) where multiple remote antenna units (RAUs) are connected to one wireless local-area network (WLAN) access point (AP) with different-length fiber links. We also present an analytical model to evaluate the throughput of the systems in the presence of both the inter-RAU hidden-node problem and fiber-length difference effect. In the model, the unequal delay induced by different fiber length is involved both in the backoff stage and in the calculation of Ts and Tc, which are the period of time when the channel is sensed busy due to a successful transmission or a collision. The throughput performances of WLAN-RoF-DAS in both basic access and request to send/clear to send (RTS/CTS) exchange modes are evaluated with the help of the derived model.

  16. A Feasibility Study of Photoacoustic Detection of Hidden Dental Caries Using a Fiber-Based Imaging System

    Directory of Open Access Journals (Sweden)

    Takuya Koyama

    2018-04-01

    Full Text Available In this paper, the feasibility of an optical fiber-based photoacoustic imaging system for detecting caries lesions inside a tooth is examined. Models of hidden caries were prepared using a pigment with an absorption spectrum similar to that of real caries lesions, and the occlusal surface of the model teeth containing the pigment was irradiated with laser pulses with a wavelength of 532 nm. An examination of the frequency spectra of the emitted photoacoustic waves revealed that the spectra from simulated caries lesions included frequency components in the range of 0.5–1.2 MHz that were not seen in the spectra from healthy parts of the teeth. This indicates that hidden caries can be detected via a photoacoustic imaging technique. Accordingly, an imaging system for clinical applications was fabricated. It consists of a bundle of hollow-optical fibers for laser radiation and an acoustic probe that is attached to the tooth surface. Results of ex vivo imaging experiments using model teeth and an extracted tooth with hidden caries lesions show that relatively large caries lesions inside teeth that are not seen in visual inspections can be detected by focusing on the above frequency components of the photoacoustic waves.

  17. An Optical Fiber-Based Sensor Array for the Monitoring of Zinc and Copper Ions in Aqueous Environments

    Directory of Open Access Journals (Sweden)

    Steven Kopitzke

    2014-02-01

    Full Text Available Copper and zinc are elements commonly used in industrial applications as aqueous solutions. Before the solutions can be discharged into civil or native waterways, waste treatment processes must be undertaken to ensure compliance with government guidelines restricting the concentration of ions discharged in solution. While currently there are methods of analysis available to monitor these solutions, each method has disadvantages, be it high costs, inaccuracy, and/or being time-consuming. In this work, a new optical fiber-based platform capable of providing fast and accurate results when performing solution analysis for these metals is described. Fluorescent compounds that exhibit a high sensitivity and selectivity for either zinc or copper have been employed for fabricating the sensors. These sensors demonstrated sub-part-per-million detection limits, 30-second response times, and the ability to analyze samples with an average error of under 10%. The inclusion of a fluorescent compound as a reference material to compensate for fluctuations from pulsed excitation sources has further increased the reliability and accuracy of each sensor. Finally, after developing sensors capable of monitoring zinc and copper individually, these sensors are combined to form a single optical fiber sensor array capable of simultaneously monitoring concentration changes in zinc and copper in aqueous environments.

  18. Dynamics of CO 2 Adsorption on Amine Adsorbents. 2. Insights Into Adsorbent Design

    KAUST Repository

    Bollini, Praveen

    2012-11-21

    Packed bed breakthrough experiments are reported for commercial zeolite 13X and 3-aminopropyl-functionalized SBA-15 silica materials with three different amine loadings. Mass and heat transfer dynamics for all four materials are modeled successfully. Amine adsorbents with open pores are found to exhibit faster mass diffusion rates compared to zeolite 13X. When amine loading is increased by coupling aminopropyl groups, premature breakthrough combined with a long tail is observed. Contrary to conventional physisorbants, finite heat losses to the column wall do not explain the long breakthrough tail. A rate model that accounts for heterogeneity in diffusion was found to accurately capture the breakthrough shape of the high loading material. Batch uptake measurements support the hypothesis that slow diffusion through the polymer phase is what hampers adsorption kinetics in the high amine loading adsorbent. The results emphasize the importance of designing materials that are not overloaded with amine sites, as excessive amine loadings can lead to depressed adsorption kinetics and premature column breakthrough. © 2012 American Chemical Society.

  19. Electronic structure of benzene adsorbed on Ni and Cu surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Weinelt, M.; Nilsson, A.; Wassdahl, N. [Uppsala Univ. (Sweden)] [and others

    1997-04-01

    Benzene has for a long time served as a prototype adsorption system of large molecules. It adsorbs with the molecular plane parallel to the surface. The bonding of benzene to a transition metal is typically viewed to involve the {pi} system. Benzene adsorbs weakly on Cu and strongly on Ni. It is interesting to study how the adsorption strength is reflected in the electronic structure of the adsorbate-substrate complex. The authors have used X-ray Emission (XE) and X-ray Absorption (XA) spectroscopies to selectively study the electronic states localized on the adsorbed benzene molecule. Using XES the occupied states can be studies and with XAS the unoccupied states. The authors have used beamline 8.0 and the Swedish endstation equipped with a grazing incidence x-ray spectrometer and a partial yield absorption detector. The resolution in the XES and XAS were 0.5 eV and 0.05 eV, respectively.

  20. Enhanced vanillin production from ferulic acid using adsorbent resin.

    Science.gov (United States)

    Hua, Dongliang; Ma, Cuiqing; Song, Lifu; Lin, Shan; Zhang, Zhaobin; Deng, Zixin; Xu, Ping

    2007-03-01

    High vanillin productivity was achieved in the batch biotransformation of ferulic acid by Streptomyces sp. strain V-1. Due to the toxicity of vanillin and the product inhibition, fed-batch biotransformation with high concentration of ferulic acid was unsuccessful. To solve this problem and improve the vanillin yield, a biotransformation strategy using adsorbent resin was investigated. Several macroporous adsorbent resins were chosen to adsorb vanillin in situ during the bioconversion. Resin DM11 was found to be the best, which adsorbed the most vanillin and the least ferulic acid. When 8% resin DM11 (wet w/v) was added to the biotransformation system, 45 g l(-1) ferulic acid could be added continually and 19.2 g l(-1) vanillin was obtained within 55 h, which was the highest vanillin yield by bioconversion until now. This yield was remarkable for exceeding the crystallization concentration of vanillin and therefore had far-reaching consequence in its downstream processing.

  1. Production of Flocculants, Adsorbents, and Dispersants from Lignin.

    Science.gov (United States)

    Chen, Jiachuan; Eraghi Kazzaz, Armin; AlipoorMazandarani, Niloofar; Hosseinpour Feizi, Zahra; Fatehi, Pedram

    2018-04-10

    Currently, lignin is mainly produced in pulping processes, but it is considered as an under-utilized chemical since it is being mainly used as a fuel source. Lignin contains many hydroxyl groups that can participate in chemical reactions to produce value-added products. Flocculants, adsorbents, and dispersants have a wide range of applications in industry, but they are mainly oil-based chemicals and expensive. This paper reviews the pathways to produce water soluble lignin-based flocculants, adsorbents, and dispersants. It provides information on the recent progress in the possible use of these lignin-based flocculants, adsorbents, and dispersants. It also critically discusses the advantages and disadvantages of various approaches to produce such products. The challenges present in the production of lignin-based flocculants, adsorbents, and dispersants and possible scenarios to overcome these challenges for commercial use of these products in industry are discussed.

  2. Order-disorder transitions in adsorbed systems on magnetic surfaces

    International Nuclear Information System (INIS)

    Aguilera-Granja, F.; Moran-Lopez, J.L.; Instituto Politecnico Nacional, Mexico City. Centro de Investigacion y de Estudios Avanzados); Falicov, L.M.

    1984-01-01

    It is investigated the effect of adsorbed atoms on the magnetic properties of ferromagnets. The Ising model is employed considering nearest neigbours with antiferromagnetic coupling between atoms. (M.W.O.) [pt

  3. Production of Flocculants, Adsorbents, and Dispersants from Lignin

    Directory of Open Access Journals (Sweden)

    Jiachuan Chen

    2018-04-01

    Full Text Available Currently, lignin is mainly produced in pulping processes, but it is considered as an under-utilized chemical since it is being mainly used as a fuel source. Lignin contains many hydroxyl groups that can participate in chemical reactions to produce value-added products. Flocculants, adsorbents, and dispersants have a wide range of applications in industry, but they are mainly oil-based chemicals and expensive. This paper reviews the pathways to produce water soluble lignin-based flocculants, adsorbents, and dispersants. It provides information on the recent progress in the possible use of these lignin-based flocculants, adsorbents, and dispersants. It also critically discusses the advantages and disadvantages of various approaches to produce such products. The challenges present in the production of lignin-based flocculants, adsorbents, and dispersants and possible scenarios to overcome these challenges for commercial use of these products in industry are discussed.

  4. Comparative analysis of the efficiencies of two low cost adsorbents ...

    African Journals Online (AJOL)

    ISHIOMA

    tanning, metallurgical operation and manufacturing have led to the release ... pulmonary fibrosis and inhibit many enzymatic functions. (Liphadzi ... sector is a low cost adsorbent for heavy metal but has ... as its economic value is less. The aim ...

  5. Low Pressure Adsorbent for Recovery & Storage Vented Hydrogen, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A high performance fullerene-based adsorbent is proposed for recovery and storage hydrogen and separating helium via pressure-swing-adsorption (PSA) process....

  6. Selectivity of β-Sitosterol Imprinted Polymers as Adsorbent

    Science.gov (United States)

    Fauziah, St.; Hariani Soekamto, Nunuk; Taba, Paulina; Bachri Amran, Muh

    2018-03-01

    Molecularly Imprinted Polymers (MIPs) are smart materials that have been used as adsorbents in separation processes of compounds because they have a memorial effect to a certain compound. In this research, MIP synthesized was used as adsorbent for β-sitosterol. The objective of the research was to know the selectivity of MIP in adsorbing β-sitosterol. The concentrations of β-sitosterol after adsorption and desorption were analyzed by a UV-Vis spectrophotometer and the selectivity test was analyzed by HPLC. Result showed that the MIP had high adsorption ability ( qe ). The recovery of β-sitosterol from MIP for the adsorption-desorption process was 68.48%. The MIP was very selective to β-sitosterol compared to cholesterol because it can adsorb β-sitosterol as many as 100%, whereas the adsorption of cholesterol was only 30.27 %.

  7. TESTING OF CARBONACEOUS ADSORBENTS FOR REMOVAL OF POLLUTANTS FROM WATER

    Directory of Open Access Journals (Sweden)

    RAISA NASTAS

    2012-03-01

    Full Text Available Testing of carbonaceous adsorbents for removal of pollutants from water. Relevant direction for improving of quality of potable water is application of active carbons at various stages of water treatments. This work includes complex research dealing with testing of a broad spectrum of carbonaceous adsorbents for removal of hydrogen sulfide and nitrite ions from water. The role of the surface functional groups of carbonaceous adsorbents, their acid-basic properties, and the influence of the type of impregnated heteroatom (N, O, or metals (Fe, Cu, Ni, on removal of hydrogen sulfide species and nitrite ions have been researched. The efficiency of the catalyst obtained from peach stones by impregnation with Cu2+ ions of oxidized active carbon was established, being recommended for practical purposes to remove the hydrogen sulfide species from the sulfurous ground waters. Comparative analysis of carbonaceous adsorbents reveals the importance of surface chemistry for oxidation of nitrite ions.

  8. Characterization of novel adsorbents for radiostrontium reduction in foods

    International Nuclear Information System (INIS)

    Puziy, A.M.; Bengtsson, G.B.; Hansen, H.S.

    1999-01-01

    Distribution coefficients, pH dependence, isotherms, kinetics and breakthrough curves of Sr binding have been measured on several types of adsorbents (carbons modified with titanium silicate, crystalline titanium silicate, mixed titanium-manganese oxide, and synthetic zeolites A4 and P) from different water solutions. It is concluded that acid-base properties of the adsorbent is very important for Sr binding. Titanium silicate based adsorbents had reduced chemical stability in an artificial food fluid below pH 2, the mixed titanium manganese oxide below pH 6, zeolite A4 below pH 5 and zeolite P below pH 7. Consideration is given to the feasibility of the adsorbents for food decontamination. (author)

  9. Adsorption of β-galactosidase on silica and aluminosilicate adsorbents

    Science.gov (United States)

    Atyaksheva, L. F.; Dobryakova, I. V.; Pilipenko, O. S.

    2015-03-01

    It is shown that adsorption of β-galactosidase of Aspergillus oryzae fungi on mesoporous and biporous silica and aluminosilicate adsorbents and the rate of the process grow along with the diameter of the pores of the adsorbent. It is found that the shape of the adsorption isotherms changes as well, depending on the texture of the adsorbent: the Michaelis constant rises from 0.3 mM for the enzyme in solution to 0.4-0.5 mM for the enzyme on a surface in the hydrolysis of o-nitrophenyl-β-D-galactopyranoside. It is concluded that β-galactosidase displays its maximum activity on the surface of biporous adsorbents.

  10. Adsorption of uranium on adsorbents produced from used tires

    International Nuclear Information System (INIS)

    Mahramanlioglu, M.

    2003-01-01

    Potential use of adsorbents produced from used tires for the removal of uranium from aqueous solutions is investigated. Two different adsorbents were used including char and activated carbon produced from used tires. The surface area was larger on activated carbon. Adsorption experiments were carried out as a function of time, adsorbent concentration, pH and initial concentration of uranium. The adsorption kinetics was found to follow the Lagergren equation. The rate constants of intraparticle diffusion and mass transfer coefficients were calculated. It was shown that the equilibrium data could be fitted by the Langmuir and Freundlich equations. The adsorption of uranium in the presence of different cations were also studied and the results were correlated with the ionic potential of the cations. It was demonstrated that the activated carbon produced from used tires can be considered as an adsorbent that has a commercial potential for uranium removal. (author)

  11. Role of adsorbates on current fluctuations in DC field emission

    International Nuclear Information System (INIS)

    Luong, M.; Bonin, B.; Long, H.; Safa, H.

    1996-01-01

    Field emission experiments in DC regime usually show important current fluctuations for a fixed electric field. These fluctuations are attributed to adsorbed layers (molecules or atoms), liable to affect the work function, height and shape of the potential barrier binding the electron in the metal. The role of these adsorbed species is investigated by showing that the field emission from a well desorbed sample is stable and reproducible and by comparing the emission from the same sample before and after desorption. (author)

  12. Simulations of the Static Friction Due to Adsorbed Molecules

    OpenAIRE

    He, Gang; Robbins, Mark O.

    2001-01-01

    The static friction between crystalline surfaces separated by a molecularly thin layer of adsorbed molecules is calculated using molecular dynamics simulations. These molecules naturally lead to a finite static friction that is consistent with macroscopic friction laws. Crystalline alignment, sliding direction, and the number of adsorbed molecules are not controlled in most experiments and are shown to have little effect on the friction. Temperature, molecular geometry and interaction potenti...

  13. Vanadium (4) complexing in phase of adsorbent with benzimidazole groups

    Energy Technology Data Exchange (ETDEWEB)

    Shvoeva, O P; Kuchava, G P; Evtikova, G A; Belyaeva, V K; Myasoedova, G V; Marov, I N [AN SSSR, Moscow (USSR). Inst. Geokhimii i Analiticheskoj Khimii

    1989-04-01

    Equilibrium and kinetic characteristics of V{sup 4+} sorption by POLYORGS XI-H adsorbent with benzimidazole groups (BIm) are investigated. Using ESR method it is stated that (VO{sup 2+}):(BIm)1:2 complex, where VO{sup 2+} is combined with nitrogen atoms of two imidazole groups, is formed in adsorbent phase. The highest distribution factor of 4.7x10{sup 3} is attained at pH6.

  14. Residence time determination for adsorbent beds of different configurations

    Energy Technology Data Exchange (ETDEWEB)

    Otermat, J.E.; Wikoff, W.O.; Kovach, J.L.

    1995-02-01

    The residence time calculations of ASME AG-1 Code, Section FC, currently specify a screen surface area method, that is technically incorrect. Test data has been obtained on Type II adsorber trays of different configurations to establish residence time in the adsorber trays. These data indicate that the air volume/carbon volume ratio or the average screen area are more appropriate for the calculation of the residence time calculation than the currently used, smallest screen area basis.

  15. Vanadium (4) complexing in phase of adsorbent with benzimidazole groups

    International Nuclear Information System (INIS)

    Shvoeva, O.P.; Kuchava, G.P.; Evtikova, G.A.; Belyaeva, V.K.; Myasoedova, G.V.; Marov, I.N.

    1989-01-01

    Equilibrium and kinetic characteristics of V 4+ sorption by POLYORGS XI-H adsorbent with benzimidazole groups (BIm) are investigated. Using ESR method it is stated that [VO 2+ ]:[BIm]1:2 complex, where VO 2+ is combined with nitrogen atoms of two imidazole groups, is formed in adsorbent phase. The highest distribution factor of 4.7x10 3 is attained at pH6

  16. Summary of Adsorption Capacity and Adsorption Kinetics of Uranium and Other Elements on Amidoxime-based Adsorbents from Time Series Marine Testing at the Pacific Northwest National Laboratory

    International Nuclear Information System (INIS)

    Gill, Gary A.; Das, Sadananda; Mayes, Richard; Saito, Tomonori; Brown, Suree S.; Tsouris, Constantinos; Tsouris, Costas; Wai, Chien M.; Pan, Horng-Bin

    2016-01-01

    The Pacific Northwest National Laboratory (PNNL) has been conducting marine testing of uranium adsorbent materials for the Fuel Resources Program, Department of Energy, Office of Nuclear Energy (DOE-NE) beginning in FY 2012. The marine testing program is being conducted at PNNL's Marine Sciences Laboratory (MSL), located at Sequim Bay, along the coast of Washington. One of the main efforts of the marine testing program is the determination of adsorption capacity and adsorption kinetics for uranium and selected other elements (e.g. vanadium, iron, copper, nickel, and zinc) for adsorbent materials provided primarily by Oak Ridge National Laboratory (ORNL), but also includes other Fuel Resources Program participants. This report summarizes the major marine testing results that have been obtained to date using time series sampling for 42 to 56 days using either flow-through column or recirculating flume exposures. The major results are highlighted in this report, and the full data sets are appended as a series of Excel spreadsheet files. Over the four year period (2012-2016) that marine testing of amidoxime-based polymeric adsorbents was conducted at PNNL's Marine Science Laboratory, there has been a steady progression of improvement in the 56-day adsorbent capacity from 3.30 g U/kg adsorbent for the ORNL 38H adsorbent to the current best performing adsorbent prepared by a collaboration between the University of Tennessee and ORNL to produce the adsorbent SB12-8, which has an adsorption capacity of 6.56 g U/kg adsorbent. This nearly doubling of the adsorption capacity in four years is a significant advancement in amidoxime-based adsorbent technology and a significant achievement for the Uranium from Seawater program. The achievements are evident when compared to the several decades of work conducted by the Japanese scientists beginning in the 1980's (Kim et al., 2013). The best adsorbent capacity reported by the Japanese scientists was 3.2 g U/kg adsorbent for a 180

  17. Summary of Adsorption Capacity and Adsorption Kinetics of Uranium and Other Elements on Amidoxime-based Adsorbents from Time Series Marine Testing at the Pacific Northwest National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Gill, Gary A. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Kuo, Li-Jung [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Strivens, Jonathan E. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Wood, Jordana R. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Schlafer, Nicholas J. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Janke, Christopher J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Das, Sadananda [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mayes, Richard [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Saito, Tomonori [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Brown, Suree S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Tsouris, Constantinos [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Tsouris, Costas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wai, Chien M. [Univ. of Idaho, Moscow, ID (United States); LCW Supercritical Technologies, Seattle, WA (United States); Pan, Horng-Bin [Univ. of Idaho, Moscow, ID (United States)

    2016-09-29

    The Pacific Northwest National Laboratory (PNNL) has been conducting marine testing of uranium adsorbent materials for the Fuel Resources Program, Department of Energy, Office of Nuclear Energy (DOE-NE) beginning in FY 2012. The marine testing program is being conducted at PNNL’s Marine Sciences Laboratory (MSL), located at Sequim Bay, along the coast of Washington. One of the main efforts of the marine testing program is the determination of adsorption capacity and adsorption kinetics for uranium and selected other elements (e.g. vanadium, iron, copper, nickel, and zinc) for adsorbent materials provided primarily by Oak Ridge National Laboratory (ORNL), but also includes other Fuel Resources Program participants. This report summarizes the major marine testing results that have been obtained to date using time series sampling for 42 to 56 days using either flow-through column or recirculating flume exposures. The major results are highlighted in this report, and the full data sets are appended as a series of Excel spreadsheet files. Over the four year period (2012-2016) that marine testing of amidoxime-based polymeric adsorbents was conducted at PNNL’s Marine Science Laboratory, there has been a steady progression of improvement in the 56-day adsorbent capacity from 3.30 g U/kg adsorbent for the ORNL 38H adsorbent to the current best performing adsorbent prepared by a collaboration between the University of Tennessee and ORNL to produce the adsorbent SB12-8, which has an adsorption capacity of 6.56 g U/kg adsorbent. This nearly doubling of the adsorption capacity in four years is a significant advancement in amidoxime-based adsorbent technology and a significant achievement for the Uranium from Seawater program. The achievements are evident when compared to the several decades of work conducted by the Japanese scientists beginning in the 1980’s (Kim et al., 2013). The best adsorbent capacity reported by the Japanese scientists was 3.2 g U/kg adsorbent for a

  18. Efforts to Consolidate Chalcogels with Adsorbed Iodine

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Brian J.; Pierce, David A.; Chun, Jaehun

    2013-08-28

    This document discusses ongoing work with non-oxide aerogels, called chalcogels, that are under development at the Pacific Northwest National Laboratory as sorbents for gaseous iodine. Work was conducted in fiscal year 2012 to demonstrate the feasibility of converting Sn2S3 chalcogel without iodine into a glass. This current document summarizes the work conducted in fiscal year 2013 to assess the consolidation potential of non-oxide aerogels with adsorbed iodine. The Sn2S3 and Sb13.5Sn5S20 chalcogels were selected for study. The first step in the process for these experiments was to load them with iodine (I2). The I2 uptake was ~68 mass% for Sn2S3 and ~50 mass% for Sb13.5Sn5S20 chalcogels. X-ray diffraction (XRD) of both sets of sorbents showed that metal-iodide complexes were formed during adsorption, i.e., SnI4 for Sn2S3 and SbI3 for Sb13.5Sn5S20. Additionally, metal-sulfide-iodide complexes were formed, i.e., SnSI for Sn2S3 and SbSI for Sb13.5Sn5S20. No XRD evidence for unreacted iodine was found in any of these samples. Once the chalcogels had reached maximum adsorption, the consolidation potential was assessed. Here, the sorbents were heated for consolidation in vacuum-sealed quartz vessels. The Sb13.5Sn5S20 chalcogel was heated both (1) in a glassy carbon crucible within a fused quartz tube and (2) in a single-containment fused quartz tube. The Sn2S3 chalcogel was only heated in a single-containment fused quartz tube. In both cases with the single-containment fused quartz experiments, the material consolidated nicely. However, in both cases, there were small fractions of metal iodides not incorporated into the final product as well as fused quartz particles within the melt due to the sample attacking the quartz wall during the heat treatment. The Sb13.5Sn5S20 did not appear to attack the glassy carbon crucible so, for future experiments, it would be ideal to apply a coating, such as pyrolytic graphite, to the inner walls of the fused quartz vessel to prevent

  19. The effects of mineral adsorbents added to broilers diet on breast meat quality

    Directory of Open Access Journals (Sweden)

    Okanović Đorđe G.

    2013-01-01

    Full Text Available The aim of these investigations was to determine the influence of mineral adsorbents “Minazel” and “Minazel Plus” added into broiler diet, on the carcass quality and nutritional, technological and sensory properties of breast meat. The examination was done on Cobb 500 provenience divided into 4 groups: control group C (fed without addition of mineral adsorbent, experimental group E I (0.5% of Minazel, experimental group E II (0.2% of Minazel Plus, experimental group E III (0.3% of Minazel Plus. The results showed that the broilers fed with the addition of mineral adsorbents, had a higher (P < 0.01 mass of chilled carcass “ready to grill“ and breast mass, than the broilers of the control group. Based on the parameters and criteria for defining the quality of chicken breast meat (pHu and L* it can be concluded that meat of all groups had in average "normal" quality. According to the results of sensory analyzed roasted breast meat, meat of experimental groups had preferable smell and tenderness. [Projekat Ministarstva nauke Republike Srbije, br. 46012

  20. A lumped-parameter model for cryo-adsorber hydrogen storage tank

    Energy Technology Data Exchange (ETDEWEB)

    Senthil Kumar, V.; Raghunathan, K. [India Science Lab, General Motors R and D, Creator Building, International Technology Park, Bangalore 560066 (India); Kumar, Sudarshan [Chemical and Environmental Sciences Lab, General Motors R and D, 30500 Mound Road, Warren, MI 48090 (United States)

    2009-07-15

    One of the primary requirements for commercialization of hydrogen fuel-cell vehicles is the on-board storage of hydrogen in sufficient quantities. On-board storage of hydrogen by adsorption on nano-porous adsorbents at around liquid nitrogen temperatures and moderate pressures is considered viable and competitive with other storage technologies: liquid hydrogen, compressed gas, and metallic or complex hydrides. The four cryo-adsorber fuel tank processes occur over different time scales: refueling over a few minutes, discharge over a few hours, dormancy over a few days, and venting over a few weeks. The slower processes i.e. discharge, dormancy and venting are expected to have negligible temperature gradients within the bed, and hence are amenable to a lumped-parameter analysis. Here we report a quasi-static lumped-parameter model for the cryo-adsorber fuel tank, and discuss the results for these slower processes. We also describe an alternative solution method for dormancy and venting based on the thermodynamic state description. (author)

  1. Gold recovery from low concentrations using nanoporous silica adsorbent

    Science.gov (United States)

    Aledresse, Adil

    The development of high capacity adsorbents with uniform porosity denoted 5%MP-HMS (5% Mercaptopropyl-Hexagonal Mesoporous Structure) to extract gold from noncyanide solutions is presented. The preliminary studies from laboratory simulated noncyanide gold solutions show that the adsorption capacities of these materials are among the highest reported. The high adsorption saturation level of these materials, up to 1.9 mmol/g (37% of the adsorbent weight) from gold chloride solutions (potassium tetrachloroaurate) and 2.9 mmol/g (57% of the adsorbent weight) from gold bromide solutions (potassium tetrabromoaurate) at pH = 2, is a noteworthy feature of these materials. This gold loading from [AuC4]- and [AuBr4 ]- solutions corresponds to a relative Au:S molar ratio of 2.5:1 and 3.8:1, respectively. These rates are significantly higher than the usual 1:1 (Au:S) ratio expected for metal ion binding with the material. The additional gold ions loaded have been spontaneously reduced to metallic gold in the mesoporous material. Experimental studies indicated high maximum adsorptions of gold as high as 99.9% recovery. Another promising attribute of these materials is their favourable adsorption kinetics. The MP-HMS reaches equilibrium (saturation) in less than 1 minute of exposure in gold bromide and less than 10 minutes in gold chloride. The MP-HMS materials adsorption is significantly improved by agitation and the adsorption capacity of Au (III) ions increases with the decrease in pH. The recovery of adsorbed gold and the regeneration of spent adsorbent were investigated for MP-HMS adsorbent. The regenerated adsorbent (MP-HMS) maintained its adsorption capacity even after repeated use and all the gold was successfully recovered from the spent adsorbent. For the fist time, a promising adsorbent system has been found that is capable of effectively concentrating gold thiosulphate complexes, whereas conventional carbon-inpulp (CIP) and carbon-in-leach (CIL) systems fail. The

  2. Technology

    Directory of Open Access Journals (Sweden)

    Xu Jing

    2016-01-01

    Full Text Available The traditional answer card reading method using OMR (Optical Mark Reader, most commonly, OMR special card special use, less versatile, high cost, aiming at the existing problems proposed a method based on pattern recognition of the answer card identification method. Using the method based on Line Segment Detector to detect the tilt of the image, the existence of tilt image rotation correction, and eventually achieve positioning and detection of answers to the answer sheet .Pattern recognition technology for automatic reading, high accuracy, detect faster

  3. Research on the theory and application of adsorbed natural gas used in new energy vehicles: A review

    Science.gov (United States)

    Nie, Zhengwei; Lin, Yuyi; Jin, Xiaoyi

    2016-09-01

    Natural gas, whose primary constituent is methane, has been considered a convincing alternative for the growth of the energy supply worldwide. Adsorbed natural gas (ANG), the most promising methane storage method, has been an active field of study in the past two decades. ANG constitutes a safe and low-cost way to store methane for natural gas vehicles at an acceptable energy density while working at substantially low pressures (3.5-4.0 MPa), allowing for conformable store tank. This work serves to review the state-of-the-art development reported in the scientific literature on adsorbents, adsorption theories, ANG conformable tanks, and related technologies on ANG vehicles. Patent literature has also been searched and discussed. The review aims at illustrating both achievements and problems of the ANG technologies- based vehicles, as well as forecasting the development trends and critical issues to be resolved of these technologies.

  4. NiO(111) nanosheets as efficient and recyclable adsorbents for dye pollutant removal from wastewater

    International Nuclear Information System (INIS)

    Song Zhi; Hu Juncheng; Chen Lifang; Richards, Ryan

    2009-01-01

    Semiconductor single-crystalline polar NiO(111) nanosheets with well-defined hexagonal holes have been investigated for application in dye adsorption and combustion processes. With regard to adsorption technologies, high surface area metal oxides have an advantage over activated carbon in that the adsorbed species can be combusted and the adsorbent reused in the case of metal oxides while regeneration of activated carbon remains challenging and thus the adsorbent/adsorbate system must be disposed of. Here, three typical textile dyes, reactive brilliant red X-3B, congo red and fuchsin red, were studied for removal from wastewater with two NiO systems and activated carbon. These studies revealed that the NiO(111) nanosheets exhibited much more favorable adsorptive properties than conventionally prepared nickel oxide powder (CP-NiO) obtained from thermal decomposition of nickel nitrate. The maximum adsorption capabilities of the three dyes on NiO(111) nanosheets reached 30.4 mg g -1 , 35.15 mg g -1 and 22 mg g -1 for reactive brilliant red X-3B, congo red and fuchsin acid, respectively, while the maximum adsorption capabilities of the three dyes on CP-NiO were only 8.4, 13.2 and 12 mg g -1 for reactive brilliant red X-3B, congo red and fuchsin acid. To simulate the adsorption isotherm, two commonly employed models, the Langmuir and the Freundlich isotherms, were selected to explicate the interaction of the dye and NiO(111). The isotherm evaluations revealed that the Langmuir model demonstrated better fit to experimental equilibrium data than the Freundlich model. The maximum predicted adsorption capacity was 36.1 mg g -1 . In addition, adsorption kinetic data of NiO(111) followed a pseudo-second-order rate for congo red. These studies infer that NiO(111) nanosheets possess desirable properties for application in adsorption and combustion applications.

  5. Study on the adsorption performance of composite adsorbent of CaCl2 and expanded graphite with ammonia as adsorbate

    International Nuclear Information System (INIS)

    Li, S.L.; Wu, J.Y.; Xia, Z.Z.; Wang, R.Z.

    2009-01-01

    A novel constant volume test unit was built to study the adsorption performance of a new type composite adsorbent. This test unit can measure the adsorption isosteres of the working pairs. The adsorption isosteres are the curves of the adsorption pressure variation with the adsorption temperatures at constant adsorption quantities. Compared to the former test results of isothermals and isobars, the isosteres are better for the calculation of the adsorption heat, desorption heat and the selection the adsorption working pairs. Three experimental results were obtained: the first result was that the expanded graphite powders were superior to the expandable graphite powders to facilitate the transportation of working fluid in the composite adsorbent. The second one was that the composite adsorbent treated by solution is more homogeneous than the simple mixed composite adsorbent and the treated composite adsorbent has a better mass transfer performance. The last one was that the adsorption isosteres was the same one not only in the heating process but also in the cooling process and this performance was not relevant to the homogeneity of the composite adsorbent

  6. Effect of fiber-based creep feed on intake, digestion, ruminal fermentation, and microbial efficiency in nursing calves.

    Science.gov (United States)

    Soto-Navarro, S A; Knight, M H; Lardy, G P; Bauer, M L; Caton, J S

    2004-12-01

    Six Angus crossbred cow-calf pairs (653 +/- 35 kg and 157 +/- 10 kg initial BW for cows and calves, respectively) were used to evaluate the influence of a fiber-based creep feed on intake, ruminal fermentation, digestion characteristics, and microbial efficiency in nursing beef calves. Cow-calf pairs were stratified by calf age and assigned randomly to one of two treatments: control (no supplement) or supplemented. Supplemented calves received 0.9 kg of a 49% soy hulls, 44% wheat middlings, 6% molasses, and 1% limestone supplement (DM basis) daily. All calves were cannulated in the rumen and duodenum and given ad libitum access to chopped brome hay (Bromus inermus L; 7.43% CP, 40.96% ADF, and 63.99% NDF; DM basis). Supplementation was initiated on May 1 (88 +/- 10.3 d calf age). Three sampling periods were conducted throughout the study (June 14 to 25, July 5 to 16, and August 9 to 20). Supplement and forage were offered at 0800 daily. Total, hay, and milk OM intakes of nursing calves were not affected by supplementation (2,014 vs. 2,328 +/- 288.8, 1,486 vs. 1,029 +/- 3,06.9, and 528 vs. 575 +/- 87.0 g/d, respectively). Milk OM intake was less (P 0.40) total-tract OM digestibility during June and August; however, during July, total-tract OM digestibility was lower (P = 0.03) for the control calves. Ruminal ammonia concentration, total VFA, and butyrate molar proportion increased (P effects on OM intake, total-tract OM digestibility, and ruminal fermentation characteristics in nursing beef calves.

  7. SERS spectra of pyridine adsorbed on nickel film prepared by magnetron sputtering

    Science.gov (United States)

    Li, Daoyong; Ouyang, Yu; Chen, Li; Cao, Weiran; Shi, Shaohua

    2011-02-01

    As a repeating well and cheaper enhancement substrate, the nickel film was fabricated with magnetron sputtering coating instrument. Surface enhanced Raman spectra (SERS) of pyridine adsorbed on this nickel film are compared with the experimental values of gaseous pyridine, the theoretical value of pyridine solution listed in other literatures and our method is better than electro-chemical etching electrode method for large scale preparation. The enhancement factor of the nickel film is calculated and the result indicates that magnetron sputtering coating technology is feasible for obtaining good SERS active surface.

  8. Microporous carbonaceous adsorbents for CO2 separation via selective adsorption

    KAUST Repository

    Zhao, Yunfeng

    2015-01-01

    Selective adsorption of CO2 has important implications for many energy and environment-related processes, which require the separation of CO2 from other gases (e.g. N2 and CH4) with high uptakes and selectivity. The development of high-performance adsorbents is one of the most promising solutions to the success of these processes. The present review is focused on the state-of-the-art of carbon-based (carbonaceous) adsorbents, covering microporous inorganic carbons and microporous organic polymers, with emphasis on the correlation between their textural and compositional properties and their CO2 adsorption/separation performance. Special attention is given to the most recently developed materials that were not covered in previous reviews. We summarize various effective strategies (N-doping, surface functionalization, extra-framework ions, molecular design, and pore size engineering) for enhancing the CO2 adsorption capacity and selectivity of carbonaceous adsorbents. Our discussion focuses on CO2/N2 separation and CO2/CH4 separation, while including an introduction to the methods and criteria used for evaluating the performance of the adsorbents. Critical issues and challenges regarding the development of high-performance adsorbents as well as some overlooked facts and misconceptions are also discussed, with the aim of providing important insights into the design of novel carbonaceous porous materials for various selective adsorption based applications. This journal is © The Royal Society of Chemistry.

  9. Adsorption behavior of lithium from seawater using manganese oxide adsorbent

    International Nuclear Information System (INIS)

    Wajima, Takaaki; Munakata, Kenzo; Uda, Tatsuhiko

    2012-01-01

    The deuterium-tritium (D-T) fusion reactor system is expected to provide the main source of electricity in the future. Large amounts of lithium will be required, dependent on the reactor design concept, and alternative resources should be found to provide lithium inventories for nuclear fusion plants. Seawater has recently become an attractive source of this element and the separation and recovery of lithium from seawater by co-precipitation, solvent extraction and adsorption have been investigated. Amongst these techniques, the adsorption method is suitable for recovery of lithium from seawater, because certain inorganic ion-exchange materials, especially spinel-type manganese oxides, show extremely high selectivity for the lithium ion. In this study, we prepared a lithium adsorbent (HMn 2 O 4 ) by elution of spinel-type lithium di-manganese-tetra-oxide (LiMn 2 O 4 ) and examined the kinetics of the adsorbent for lithium ions in seawater using a pseudo-second-order kinetic model. The intermediate, LiMn 2 O 4 , can be synthesized from LiOH·H 2 O and Mn 3 O 4 , from which the lithium adsorbent can subsequently be prepared via acid treatment., The adsorption kinetics become faster and the amount of lithium adsorbed on the adsorbent increases with increasing solution temperature. The thermodynamic values, ΔG 0 , ΔH 0 and ΔS 0 , indicate that adsorption is an endothermic and spontaneous process. (author)

  10. Kinetics of conformational changes of fibronectin adsorbed onto model surfaces.

    Science.gov (United States)

    Baujard-Lamotte, L; Noinville, S; Goubard, F; Marque, P; Pauthe, E

    2008-05-01

    Fibronectin (FN), a large glycoprotein found in body fluids and in the extracellular matrix, plays a key role in numerous cellular behaviours. We investigate FN adsorption onto hydrophilic bare silica and hydrophobic polystyrene (PS) surfaces using Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR) in aqueous medium. Adsorption kinetics using different bulk concentrations of FN were followed for 2h and the surface density of adsorbed FN and its time-dependent conformational changes were determined. When adsorption occurs onto the hydrophilic surface, FN molecules keep their native conformation independent of the adsorption conditions, but the amount of adsorbed FN increases with time and the bulk concentration. Although the protein surface density is the same on the hydrophobic PS surface, this has a strong impact on the average conformation of the adsorbed FN layer. Indeed, interfacial hydration changes induced by adsorption onto the hydrophobic surface lead to a decrease in unhydrated beta-sheet content and cause an increase in hydrated beta-strand and hydrated random domain content of adsorbed FN. This conformational change is mainly dependent on the bulk concentration. Indeed, at low bulk concentrations, the secondary structures of adsorbed FN molecules undergo strong unfolding, allowing an extended and hydrated conformation of the protein. At high bulk concentrations, the molecular packing reduces the unfolding of the stereoregular structures of the FN molecules, preventing stronger spreading of the protein.

  11. Application of Molecular Adsorber Coatings in Chamber A for the James Webb Space Telescope

    Science.gov (United States)

    Abraham, Nithin S.

    2017-01-01

    As a coating made of highly porous zeolite materials, the Molecular Adsorber Coating (MAC) was developed to capture outgassed molecular contaminants, such as hydrocarbons and silicones. For spaceflight applications, the adsorptive capabilities of the coating can alleviate on-orbit outgassing concerns on or near sensitive surfaces and instruments within the spacecraft. Similarly, this sprayable paint technology has proven to be significantly beneficial for ground-based space applications, in particular, for vacuum chamber environments. This presentation describes the application of the MAC technology for the James Webb Space Telescope (JWST) at NASA Johnson Space Center (JSC). The coating was used as a mitigation tool to entrap outgassed contaminants, specifically silicone-based diffusion pump oil, from within JSCs cryogenic optical vacuum chamber test facility called Chamber A. This presentation summarizes the background, fabrication, installation, chemical analysis test results, and future plans for the MAC technology, which was effectively used to protect the JWST test equipment from vacuum chamber contamination. As a coating made of highly porous zeolite materials, the Molecular Adsorber Coating (MAC) was developed to capture outgassed molecular contaminants, such as hydrocarbons and silicones. For spaceflight applications, the adsorptive capabilities of the coating can alleviate on-orbit outgassing concerns on or near sensitive surfaces and instruments within the spacecraft. Similarly, this sprayable paint technology has proven to be significantly beneficial for ground-based space applications, in particular, for vacuum chamber environments. This presentation describes the application of the MAC technology for the James Webb Space Telescope (JWST) at NASA Johnson Space Center (JSC). The coating was used as a mitigation tool to entrap outgassed contaminants, specifically silicone-based diffusion pump oil, from within JSCs cryogenic optical vacuum chamber test

  12. Effectiveness Study of Drinking Water Treatment Using Clays/Andisol Adsorbent in Lariat Heavy Metal Cadmium (Cd) and Bacterial Pathogens

    Science.gov (United States)

    Pranoto; Inayati; Firmansyah, Fathoni

    2018-04-01

    Water is a natural resource that is essential for all living creatures. In addition, water also caused of disease affecting humans. The existence of one of heavy metal pollutants cadmium (Cd) in the body of water is an environmental problem having a negative impact on the quality of water resources. Adsorption is one of the ways or methods that are often used for the treatment of wastewater. Clay and allophanic soil were used as Cd adsorbent by batch method. Ceramic filter was used to reduce Cd concentration in the ground water. This study aims to determine the effect of the composition of clay and Allophane, activation temperature and contact time on the adsorption capacity of Cd in the model solution. The optimum adsorption condition and the effectiveness of drinking water treatment in accordance with Regulation of the Minister of Health using clay/Andisol adsorbents in ensnare heavy metals Cd and bacterial pathogens. Identification and characterization of adsorbent is done by using NaF, Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), specific surface area and total acidity specific. The Cd metal concentrations were analysed by atomic absorption spectroscopy. Adsorption isotherms determined by Freundlich and Langmuir equations. Modified water purification technology using ceramic filters are made with a mixture of clay and Andisol composition. The results showed samples of clay and Andisol containing minerals. The optimum condition of adsorption was achieved at 200 °C of activation temperature, 60 minutes of contact time and the 60:40 of clay:Andisol adsorbent composition. Freundlich isotherm represented Cd adsorption on the clay/Andisol adsorbent with a coefficient of determination (R2=0.99) and constant (k=1.59), higher than Langmuir (R2=0.89). The measurement results show the water purification technology using ceramic filters effectively reduce E. coli bacterial and Cd content in the water.

  13. Quantitative relationship between adsorbed amount of solute and solvent composition

    International Nuclear Information System (INIS)

    Wang Yan; Geng Xindu; Zebolsky, Don M.

    2003-01-01

    A new adsorption isotherm that relates the amount of solute adsorbed to the solvent concentration is proposed. The new equation is derived from Geng and Shi's stoichiometric displacement model for adsorption (SDM-A). The obtained equation may be simplified to an expression containing two parameters. The equation with two parameters, valid for low concentrations of solute, is a logarithmically linear relationship. The intercept contains a thermodynamic equilibrium constant of the solute displacing solvent from the adsorbent. The slope is the negative value of the stoichiometric displacement parameter (Z), the average total number of solvent molecules displaced from an active site on the adsorbent and from the solute. Tests with a homologous series of aromatic alcohols by frontal analysis in reversed phase liquid chromatography demonstrate that experimental results fit the equation well

  14. Lotus Dust Mitigation Coating and Molecular Adsorber Coating

    Science.gov (United States)

    O'Connor, Kenneth M.; Abraham, Nithin S.

    2015-01-01

    NASA Goddard Space Flight Center has developed two unique coating formulations that will keep surfaces clean and sanitary and contain contaminants.The Lotus Dust Mitigation Coating, modeled after the self-cleaning, water-repellant lotus leaf, disallows buildup of dust, dirt, water, and more on surfaces. This coating, has been successfully tested on painted, aluminum, glass, silica, and some composite surfaces, could aid in keeping medical assets clean.The Molecular Adsorber Coating is a zeolite-based, sprayable molecular adsorber coating, designed to prevent outgassing in materials in vacuums. The coating works well to adsorb volatiles and contaminates in manufacturing and processing, such as in pharmaceutical production. The addition of a biocide would also aid in controlling bacteria levels.

  15. Solid adsorbents for removal of hydrogen sulphide from hot gas

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E.; Yumura, Motoo

    1986-04-01

    A wide range of solids have been tested as potential adsorbents for H/sub 2/S removal from hot gas. These solids can be divided into two main groups, i.e., the adsorbents containing alkaline earth metals and those containing transition metals. Among the former, calcium oxide and naturally occurring materials such as limestone, dolomite and calcium silicate have attracted a great deal of attention. The adsorbents of the second group include iron oxide alone or in combination with some supports, zinc oxide, zinc ferrite and manganese oxide. The materials containing both the alkaline earth metals and transition metals, e.g., manganese nodules, fly ash and the reject from the aluminium industry (red mud) have been evaluated as well.

  16. Radioactive diffusion gaseous probe technique for study adsorbent structure inhomogeneity

    International Nuclear Information System (INIS)

    Zyuzin, A.Yu.; Korobkov, V.I.; Bekman, I.N.

    1990-01-01

    One of the versions of the method of diffusion gaseous probe - method of longitudinal shear in combination with autoradiography (ARG) - was used for characterising sorbents and catalysts, which are considered to be promising for reprocessing of sulfur-containing natural gases. Hydrogen sulfide, labelled with 35 S was used as diffusion radioactive probe. Zeolite granules of 4A type and granulated adsorbents on the basis of CR and AM aluminium oxides, which are industrial catalysts of Clauss reaction developed at SNEA company, were used as objects under investigation. It is shown that technique for fabrication of 4A zeolite granules leads to asymmetrical pore distribution over the granule diameter. Technique for AM granule fabrication leads to occuRrence of local inhomogeneities of the structure in the form of narrow coaxial rings with decreased or increased local adsorption ability. Granules of adsorbent of CR type are characterized by rather homogeneous structure. It is recommended to use the mentioned method for industrial adsorbent diagnosis

  17. Heat transfer between adsorbate and laser-heated hot electrons

    International Nuclear Information System (INIS)

    Ueba, H; Persson, B N J

    2008-01-01

    Strong short laser pulses can give rise to a strong increase in the electronic temperature at metal surfaces. Energy transfer from the hot electrons to adsorbed molecules may result in adsorbate reactions, e.g. desorption or diffusion. We point out the limitations of an often used equation to describe the heat transfer process in terms of a friction coupling. We propose a simple theory for the energy transfer between the adsorbate and hot electrons using a newly introduced heat transfer coefficient, which depends on the adsorbate temperature. We calculate the transient adsorbate temperature and the reaction yield for a Morse potential as a function of the laser fluency. The results are compared to those obtained using a conventional heat transfer equation with temperature-independent friction. It is found that our equation of energy (heat) transfer gives a significantly lower adsorbate peak temperature, which results in a large modification of the reaction yield. We also consider the heat transfer between different vibrational modes excited by hot electrons. This mode coupling provides indirect heating of the vibrational temperature in addition to the direct heating by hot electrons. The formula of heat transfer through linear mode-mode coupling of two harmonic oscillators is applied to the recent time-resolved study of carbon monoxide and atomic oxygen hopping on an ultrafast laser-heated Pt(111) surface. It is found that the maximum temperature of the frustrated translation mode can reach high temperatures for hopping, even when direct friction coupling to the hot electrons is not strong enough

  18. SAPO-34 coated adsorbent heat exchanger for adsorption chillers

    International Nuclear Information System (INIS)

    Freni, Angelo; Bonaccorsi, Lucio; Calabrese, Luigi; Caprì, Angela; Frazzica, Andrea; Sapienza, Alessio

    2015-01-01

    In this work, adsorbent coatings on aluminum surfaces were prepared by dip-coating method starting from a water suspension of SAPO-34 zeolite and a silane-based binder. Silane-zeolite coatings morphology and surface coverage grade were evaluated by scanning electron microscopy. Adhesive and mechanical properties were evaluated by peel, pull-off, impact and micro-hardness tests, confirming the good interaction between metal substrate, binder and zeolite. Adsorption equilibrium and kinetics of water vapour adsorption on the adsorbent coating were studied in the range T = 30–150 °C and pH 2 O = 11 mbar using a CAHN 2000 thermo-balance. It was found that, in the investigated conditions, the organic binder doesn't affect the water adsorption capacity and adsorption kinetics of the original SAPO-34 zeolite. Subsequently, the zeolite coating was applied on a finned flat-tubes aluminum heat exchanger realizing a full-scale AdHEx with an uniform adsorbent coating 0.1 mm thick and a metal/adsorbent mass ratio = 6. The cooling capacity of the realized coated AdHEx was measured by a lab-scale adsorption chiller under realistic operating conditions for air conditioning applications. The coated AdHEx produced up to 675 W/kg ads specific cooling power with a cycle time of 5 min. Adsorption stability of the coated adsorber subjected to 600 sorption cycles was successfully verified. - Highlights: • Adsorbent coatings on aluminum surfaces were prepared by dip-coating method. • Silane-zeolite coatings morphology, and mechanical properties were studied. • The zeolite coating was applied on a finned flat-tubes aluminum heat exchanger. • The coated AdHEx was tested in a lab scale adsorption chiller

  19. Hydrogen molecule on lithium adsorbed graphene: A DFT study

    International Nuclear Information System (INIS)

    Kaur, Gagandeep; Gupta, Shuchi; Gaganpreet; Dharamvir, Keya

    2016-01-01

    Electronic structure calculations for the adsorption of molecular hydrogen on lithium (Li) decorated and pristine graphene have been studied systematically using SIESTA code [1] within the framework of the first-principle DFT under the Perdew-Burke-Ernzerhof (PBE) form of the generalized gradient approximation (GGA)[2], including spin polarization. The energy of adsorption of hydrogen molecule on graphene is always enhanced by the presence of co-adsorbed lithium. The most efficient adsorption configuration is when H 2 is lying parallel to lithium adsorbed graphene which is in contrast to its adsorption on pristine graphene (PG) where it prefers perpendicular orientation.

  20. Surface characterization of adsorbed asphaltene on a stainless steel surface

    International Nuclear Information System (INIS)

    Abdallah, W.A.; Taylor, S.D.

    2007-01-01

    X-ray photoelectron spectroscopy was used to characterize a single layer of adsorbed asphaltene on a metallic surface. The deposits were created by immersing a stainless steel disc into a dilute asphaltene solution with either toluene or dichloromethane as the solvent, although the toluene solution allowed for better control of the adsorbed asphaltene layer and less atmospheric oxygen contamination. The analyses for C 1s, S 2p 3/2 , N 1s and O 1s photoemission peaks indicated that different functional groups are present in the asphaltene layer including carboxylic, pyrrolic, pyridininc, thiophenic and sulfite, with slight differences in their binding energies

  1. Adsorbates in a Box: Titration of Substrate Electronic States

    Science.gov (United States)

    Cheng, Zhihai; Wyrick, Jonathan; Luo, Miaomiao; Sun, Dezheng; Kim, Daeho; Zhu, Yeming; Lu, Wenhao; Kim, Kwangmoo; Einstein, T. L.; Bartels, Ludwig

    2010-08-01

    Nanoscale confinement of adsorbed CO molecules in an anthraquinone network on Cu(111) with a pore size of ≈4nm arranges the CO molecules in a shell structure that coincides with the distribution of substrate confined electronic states. Molecules occupy the states approximately in the sequence of rising electron energy. Despite the sixfold symmetry of the pore boundary itself, the adsorbate distribution adopts the threefold symmetry of the network-substrate system, highlighting the importance of the substrate even for such quasi-free-electron systems.

  2. Use of kaolin as a potential low-cost adsorbent for the removal of malachite green from colored effluents

    Energy Technology Data Exchange (ETDEWEB)

    Foletto, E.L.; Caponi, N.; Collazzo, G.C.; Jahn, S.L.; Dotto, G.L.; Mazutti, M.A. [Universidade Federal de Santa Maria (UFSM), RS (Brazil)

    2016-07-01

    Full text: This study investigated the potential of raw kaolin as a low-cost adsorbent for the removal Malachite Green (MG) from colored effluents. The morphology, chemical structure and the surface properties of the adsorbent were investigated by characterization techniques such as X-ray diffraction, N2 adsorption-desorption isotherms, Fourier transform infrared spectroscopy, X-ray fluorescence spectroscopy and scanning electron microscopy. A possible technological application of kaolin is the MG removal from aqueous media, which was investigated by batch adsorption experiments. The adsorption kinetics was studied using the pseudo-first order, pseudo-second order and Elovich models. The adsorption isotherms were studied using Langmuir, Freundlich and Sips models. Maximum adsorption capacity was found to be 128 mg g-1, and this satisfactory result may be associated to some properties of adsorbent. Therefore, the results of this investigation revealed that kaolin can be utilized as a promising low-cost adsorbent to remove MG from colored effluents. (author)

  3. Recent progress on R and D of innovative extractants and adsorbents for partitioning of minor actinides at JAEA

    International Nuclear Information System (INIS)

    Kimura, Takaumi; Morita, Yasuji; Koma, Yoshikazu

    2010-01-01

    The R and D effort on partitioning of minor actinides (MA) at the Japan Atomic Energy Agency (JAEA) has been concentrated on development and improvement of innovative extractants and adsorbents as the fundamental studies and of MA recovery process as the advanced aqueous reprocessing system in fast reactor cycle technology development (FaCT) project. This paper reviews current status and prospects of the R and D activities on the partitioning of MA at JAEA. (authors)

  4. Structural and thermodynamic characterization of modified cellulose fiber-based materials and related interactions with water vapor

    Energy Technology Data Exchange (ETDEWEB)

    Bedane, Alemayehu H., E-mail: Alemayehu.Bedane@unb.ca; Xiao, Huining, E-mail: hxiao@unb.ca; Eić, Mladen, E-mail: meic@unb.ca; Farmahini-Farahani, Madjid, E-mail: Madjid.Farahani@unb.ca

    2015-10-01

    Highlights: • Coating on paper increases the specific surface area but decreases the pore diameter. • Pore size reduction and decrease of hydrophilic property caused reduction in WVTRs. • The low monolayer moisture content of the sample is generally related to the low WVTR. • The net isosteric heats of adsorption decreased with increased sample moisture content. • FT-IR results reveal the formation of water clusters at higher relative humidities. - Abstract: In this study, the surface characteristics, water vapor interactions, and state of water adsorbed on unmodified and coated paper samples were investigated in an attempt to obtain a better understanding of the fundamental principles related to thermodynamics of this process, as well as to provide essential insight that could be used for further improvement of the papers’ barrier properties. Based on the BET measurement, the coated paper samples showed higher specific surface areas than unmodified paper; however, their mean pore diameters are smaller. The BJH method was used for pore size distribution analysis. Hydrophobic properties of the paper samples were determined from experimental isotherms, e.g., monolayer moisture content, and these results have been related to the water vapor transfer rates (WVTRs) showing a complex nature of these relations. The highest peak corresponding to the modified samples with smaller pore sizes was found to be in the range of 1–30 nm, while it was in the 30–100 nm pore size range for unmodified paper. The net isosteric heats of sorption for different unmodified and modified paper samples were determined from water vapor adsorption isotherms measured at 15, 25, and 35 °C. The net isosteric heats of sorption decreased with an increase of moisture content after reaching the maximum values at 12.53, 15.25, 14.71, 23.2, and 22.77 kJ/mol for unmodified, zein grafted, calendered coated, PLA, and PHBV coated papers, respectively. The state of adsorbed water and water

  5. Solid Adsorbents for Low-Temperature CO{sub 2} Capture with Low-Energy Penalties Leading to More Effective Integrated Solutions for Power Generation and Industrial Processes

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Nannan [Chinese Academy of Sciences Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai (China); Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham (United Kingdom); Tang, Zhiyong; Wei, Wei [Chinese Academy of Sciences Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai (China); Snape, Colin Edward [Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham (United Kingdom); Sun, Yuhan, E-mail: sunyh@sari.ac.cn [Chinese Academy of Sciences Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai (China)

    2015-03-09

    CO{sub 2} capture represents the key technology for CO{sub 2} reduction within the framework of CO{sub 2} capture, utilization, and storage (CCUS). In fact, the implementation of CO{sub 2} capture extends far beyond CCUS since it will link the CO{sub 2} emission and recycling sectors, and when renewables are used to provide necessary energy input, CO{sub 2} capture would enable a profitable zero- or even negative-emitting and integrated energy–chemical solution. To this end, highly efficient CO{sub 2} capture technologies are needed, and adsorption using solid adsorbents has the potential to be one of the ideal options. Currently, the greatest challenge in this area is the development of adsorbents with high performance that balances a range of optimization-needed factors, those including costs, efficiency, and engineering feasibility. In this review, recent advances on the development of carbon-based and immobilized organic amines-based CO{sub 2} adsorbents are summarized, the selection of these particular categories of materials is because they are among the most developed low-temperature (<100°C) CO{sub 2} adsorbents up to date, which showed important potential for practical deployment at pilot-scale in the near future. Preparation protocols, adsorption behaviors as well as pros and cons of each type of the adsorbents are presented, it was concluded that encouraging results have been achieved already, however, the development of more effective adsorbents for CO{sub 2} capture remains challenging and further innovations in the design and synthesis of adsorbents are needed.

  6. Mercury chemisorption by sulfur adsorbed in porous materials

    NARCIS (Netherlands)

    Steijns, M.; Peppelenbos, A.; Mars, P.

    1976-01-01

    The sorption of mercury vapor by adsorbed sulfur in the zeolites CaA (= 5A) and NaX (=13X) and two types of active carbon has been measured at a temperature of 50°C. With increasing degree of micropore filling by sulfur the fraction of sulfur accessible to mercury atoms decreased for CaA and NaX.

  7. Electrospun chitosan/baker's yeast nanofibre adsorbent: preparation ...

    Indian Academy of Sciences (India)

    poration, complexation, reverse osmosis and membrane pro- cesses [2–4]. ... activities and some human activities such as exploitation of uranium and ... bre adsorbent for U(VI) and Th(IV) removal from aqueous solutions. 2. Experimental ..... Adsorption capacity of uranium(VI) and thorium(IV) in binary systems. where. H.

  8. Substrate induced ordering of molecular adsorbates on Au(111)

    International Nuclear Information System (INIS)

    Schott, J.H.; White, H.S.; Arana, C.R.

    1992-01-01

    Using scanning tunneling microscopy in dimethylformate, [Ru(bpy) 2 (bpy-(CH 2 ) x -bpy) 2+ ] (x = 4 and 5) monolayers adsorbed on the unreconstructed and √3 x 22 reconstructed surfaces of Au(111) were imaged in this paper. The substrate had a highly ordered pattern on the reconstructed surface, but random spatial distribution on the unreconstructed surface. 17 refs., 3 figs

  9. Removal of nickel from wastewater using an agricultural adsorbent

    African Journals Online (AJOL)

    2009-11-26

    Nov 26, 2009 ... qmax is the theoretical maximum adsorption capacity of the adsorbent (mg/g). KL is the Langmuir affinity constant (ℓ/mg). Ce is the supernatant equilibrium concentration of the system (mg/ℓ) (Febrianto et al., 2009). The Freundlich isotherm model can also be expressed in the linearised logarithmic form (Eq.

  10. Magnetic-supported cucurbituril: A recyclable adsorbent for the ...

    Indian Academy of Sciences (India)

    Administrator

    removal of humic acid from simulated water. QIN YANG* ... The commonly used adsorbents are activated carbon. (Deng and Bai ... Q[n] is practically insoluble in all common organic solvents. ... Q[n] has other advantages such as its strong rigid structure .... and it does not result in the phase change of Fe3O4. In addition ...

  11. Interactions between adsorbed macromolecules : measurements on emulsions and liquid films

    NARCIS (Netherlands)

    Vliet, van T.

    1977-01-01

    The aim of this study was to gain more insight into the factors, determining the inter- and intramolecular interactions between adsorbed macromolecules. To that end several experimental and theoretical approaches were followed, using well-defined systems. It was shown that these

  12. Analytical phase diagrams for colloids and non-adsorbing polymer

    NARCIS (Netherlands)

    Fleer, G.J.; Tuinier, R.

    2008-01-01

    We review the free-volume theory (FVT) of Lekkerkerker et al. [Europhys. Lett. 20 (1992) 5591 for the phase behavior of colloids in the presence of non-adsorbing polymer and we extend this theory in several aspects: (i) We take the solvent into account as a separate component and show that the

  13. Application of adsorbent as a novel technique during ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-09-17

    Sep 17, 2008 ... hydrophilic compound (carbon), thermally activated at temperatures of 300, 500, 700 and ... carbon in microbial degradation of anthracene, elicits an enhanced disappearance rate of the ... persistence, toxicity and their tendency to bioaccumulate ... paper therefore, investigates the use of adsorbent (acti-.

  14. Airclad fiber laser technology

    DEFF Research Database (Denmark)

    Hansen, Kim P.; Olausson, Christina Bjarnal Thulin; Broeng, Jes

    2011-01-01

    High-power fiber lasers and amplifiers have gained tremendous momentum in the last 5 years. Many of the traditional manufacturers of gas and solid-state lasers are now pursuing the fiber-based systems, which are displacing the conventional technology in many areas. High-power fiber laser systems...... require reliable fibers with large cores, stable mode quality, and good power handling capabilities-requirements that are all met by the airclad fiber technology. In the present paper we go through many of the building blocks needed to build high-power systems and we show an example of a complete airclad...... laser system. We present the latest advancements within airclad fiber technology including a new 100 m single-mode polarization-maintaining rod-type fiber capable of amplifying to megawatt power levels. Furthermore, we describe the novel airclad-based pump combiners and their use in a completely...

  15. Airclad fiber laser technology

    DEFF Research Database (Denmark)

    Hansen, Kim P.; Olausson, Christina Bjarnal Thulin; Broeng, Jes

    2008-01-01

    High-power fiber lasers and amplifiers have gained tremendous momentum in the last five years, and many of the traditional manufactures of gas and solid-state lasers are pursuing the attractive fiber-based systems, which are now displacing the old technology in many areas. High-power fiber laser...... systems require specially designed fibers with large cores and good power handling capabilities - requirements that are all met by the airclad fiber technology. In the present paper we go through many of the building blocks needed to build high-power systems and we show an example of a complete airclad...... laser system. We present the latest advancements within airclad fiber technology including a new 70 μm single-mode polarization-maintaining rod-type fiber capable of amplifying to MW power levels. Furthermore we describe the novel airclad based pump combiners and their use in a completely monolithic 350...

  16. Direct analysis of intact biological macromolecules by low-energy, fiber-based femtosecond laser vaporization at 1042 nm wavelength with nanospray postionization mass spectrometry.

    Science.gov (United States)

    Shi, Fengjian; Flanigan, Paul M; Archer, Jieutonne J; Levis, Robert J

    2015-03-17

    A fiber-based laser with a pulse duration of 435 fs and a wavelength of 1042 nm was used to vaporize biological macromolecules intact from the condensed phase into the gas phase for nanospray postionization and mass analysis. Laser vaporization of dried standard protein samples from a glass substrate by 10 Hz bursts of 20 pulses having 10 μs pulse separation and energy resulted in signal comparable to a metal substrate. The protein signal observed from an aqueous droplet on a glass substrate was negligible compared to either a droplet on metal or a thin film on glass. The mass spectra generated from dried and aqueous protein samples by the low-energy, fiber laser were similar to the results from high-energy (500 μJ), 45-fs, 800-nm Ti:sapphire-based femtosecond laser electrospray mass spectrometry (LEMS) experiments, suggesting that the fiber-based femtosecond laser desorption mechanism involves a nonresonant, multiphoton process, rather than thermal- or photoacoustic-induced desorption. Direct analysis of whole blood performed without any pretreatment resulted in features corresponding to hemoglobin subunit-heme complex ions. The observation of intact molecular ions with low charge states from protein, and the tentatively assigned hemoglobin α subunit-heme complex from blood suggests that fiber-based femtosecond laser vaporization is a "soft" desorption source at a laser intensity of 2.39 × 10(12) W/cm(2). The low-energy, turnkey fiber laser demonstrates the potential of a more robust and affordable laser for femtosecond laser vaporization to deliver biological macromolecules into the gas phase for mass analysis.

  17. Adsorbed natural gas usage in vehicles; Uso veicular do gas natural adsorvido

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Flavio Barboza; Miller, Francisco Mateus; Moura, Newton Reis de [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2004-07-01

    This paper presents and evaluates the actual state of development of the natural gas storage in activated carbons (ANG - adsorbed natural gas) for vehicles applications. This paper also presents the technological challenges that must be overcome to turn ANG viable for vehicles applications. The main results published in ANG, its theoretical limit and a preliminary comparison between the ANG and the GNC technologies are also presented in this work. The parameters used in that comparison were storage capacity, reservoir's weight and volume. The maximum methane storage capacity in activated carbon monoliths (theoretical limit), determined by molecular simulation, is lower than the CNG ones. Therefore, the ANG contribution to vehicles applications is not related to a higher storage capacity but to its lower working pressure, that represents an advantage by the following aspects: reduction or elimination the loss of useful space inside the vehicle; safety and price reduction of NG at fueling station. (author)

  18. Natural material adsorbed onto a polymer to enhance immune function

    Directory of Open Access Journals (Sweden)

    Reinaque AP

    2012-08-01

    Full Text Available Ana Paula Barcelos Reinaque,1 Eduardo Luzía França,2 Edson Fredulin Scherer,3 Mayra Aparecida Côrtes,1 Francisco José Dutra Souto,4 Adenilda Cristina Honorio-França51Post Graduate Program in Material Science, 2Institute of Biological and Health Science, Federal University of Mato Grosso, Barra do Garças, 3Post Graduate Program in Material Science, Institute of Biological and Health Science, Federal University of Mato Grosso, Pontal do Araguaia, 4Faculty of Medical Sciences, Federal University of Mato Grosso, Cuiabá, 5Institute of Biological and Health Science, Federal University of Mato Grosso, Pontal do Araguaia, MT, BrazilBackground: In this study, we produced poly(ethylene glycol (PEG microspheres of different sizes and adsorbing a medicinal plant mixture, and verified their effect in vitro on the viability, superoxide production, and bactericidal activity of phagocytes in the blood.Methods: The medicinal plant mixture was adsorbed onto PEG microspheres and its effects were evaluated by flow cytometry and fluorescence microscopy.Results: Adsorption of the herbal mixture onto the PEG microspheres was achieved and the particles were internalized by phagocytes. PEG microspheres bearing the adsorbed herbal mixture stimulated superoxide release, and activated scavenging and microbicidal activity in phagocytes. No differences in functional activity were observed when the phagocytes were not incubated with PEG microspheres bearing the adsorbed herbal mixture.Conclusion: This system may be useful for the delivery of a variety of medicinal plants and can confer additional protection against infection. The data reported here suggest that a polymer adsorbed with a natural product is a treatment alternative for enhancing immune function.Keywords: natural product, polymer, adsorption, immune function, phagocytes

  19. Treatment of a simulated textile wastewater in a sequencing batch reactor (SBR) with addition of a low-cost adsorbent

    International Nuclear Information System (INIS)

    Santos, Sílvia C.R.; Boaventura, Rui A.R.

    2015-01-01

    Highlights: • Treating textile dyeing effluents by SBR coupled with waste sludge adsorption. • Metal hydroxide sludge: a good adsorbent for a direct textile dye. • Good adsorption capacities were found with the low-cost adsorbent. • Adsorbent performance considerably reduced by auxiliary products. • Color removal complies with discharge limits. - Abstract: Color removal from textile wastewaters, at a low-cost and consistent technology, is even today a challenge. Simultaneous biological treatment and adsorption is a known alternative to the treatment of wastewaters containing biodegradable and non-biodegradable contaminants. The present work aims at evaluating the treatability of a simulated textile wastewater by simultaneously combining biological treatment and adsorption in a SBR (sequencing batch reactor), but using a low-cost adsorbent, instead of a commercial one. The selected adsorbent was a metal hydroxide sludge (WS) from an electroplating industry. Direct Blue 85 dye (DB) was used in the preparation of the synthetic wastewater. Firstly, adsorption kinetics and equilibrium were studied, in respect to many factors (temperature, pH, WS dosage and presence of salts and dyeing auxiliary chemicals in the aqueous media). At 25 °C and pH 4, 7 and 10, maximum DB adsorption capacities in aqueous solution were 600, 339 and 98.7 mg/g, respectively. These values are quite considerable, compared to other reported in literature, but proved to be significantly reduced by the presence of dyeing auxiliary chemicals in the wastewater. The simulated textile wastewater treatment in SBR led to BOD 5 removals of 53–79%, but color removal was rather limited (10–18%). The performance was significantly enhanced by the addition of WS, with BOD 5 removals above 91% and average color removals of 60–69%

  20. Treatment of a simulated textile wastewater in a sequencing batch reactor (SBR) with addition of a low-cost adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Sílvia C.R., E-mail: scrs@fe.up.pt; Boaventura, Rui A.R.

    2015-06-30

    Highlights: • Treating textile dyeing effluents by SBR coupled with waste sludge adsorption. • Metal hydroxide sludge: a good adsorbent for a direct textile dye. • Good adsorption capacities were found with the low-cost adsorbent. • Adsorbent performance considerably reduced by auxiliary products. • Color removal complies with discharge limits. - Abstract: Color removal from textile wastewaters, at a low-cost and consistent technology, is even today a challenge. Simultaneous biological treatment and adsorption is a known alternative to the treatment of wastewaters containing biodegradable and non-biodegradable contaminants. The present work aims at evaluating the treatability of a simulated textile wastewater by simultaneously combining biological treatment and adsorption in a SBR (sequencing batch reactor), but using a low-cost adsorbent, instead of a commercial one. The selected adsorbent was a metal hydroxide sludge (WS) from an electroplating industry. Direct Blue 85 dye (DB) was used in the preparation of the synthetic wastewater. Firstly, adsorption kinetics and equilibrium were studied, in respect to many factors (temperature, pH, WS dosage and presence of salts and dyeing auxiliary chemicals in the aqueous media). At 25 °C and pH 4, 7 and 10, maximum DB adsorption capacities in aqueous solution were 600, 339 and 98.7 mg/g, respectively. These values are quite considerable, compared to other reported in literature, but proved to be significantly reduced by the presence of dyeing auxiliary chemicals in the wastewater. The simulated textile wastewater treatment in SBR led to BOD{sub 5} removals of 53–79%, but color removal was rather limited (10–18%). The performance was significantly enhanced by the addition of WS, with BOD{sub 5} removals above 91% and average color removals of 60–69%.

  1. Determination of Adsorption Capacity and Kinetics of Amidoxime-Based Uranium Adsorbent Braided Material in Unfiltered Seawater Using a Flume Exposure System

    International Nuclear Information System (INIS)

    Gill, Gary A.; Kuo, Li-Jung; Strivens, Jonathan E.; Park, Jiyeon; Bonheyo, George T.; Jeters, Robert T.; Schlafer, Nicholas J.; Wood, Jordana R.

    2015-01-01

    PNNL has developed a recirculating flume system for exposing braided adsorbent material to natural seawater under realistic temperature and flow-rate exposure conditions. The flumes are constructed of transparent acrylic material; they allow external light to pass into the flumes and permit photosynthetic growth of naturally present marine organisms (biofouling). Because the system consists of two flumes, replicate experiments can be conducted in which one of the flumes can be manipulated relative to the other. For example, one flume can be darkened to eliminate light exposure by placing a black tarp over the flume such that dark/light experiments can be conducted. Alternatively, two different braided adsorbents can be exposed simultaneously with no potential cross contamination issues. This report describes the first use of the PNNL flume system to study the impact of biofouling on adsorbent capacity. Experiments were conducted with the ORNL AI8 braided adsorbent material in light-exposed and darkened flumes for a 42-day exposure experiment. The major objective of this effort is to develop a system for the exposure of braided adsorbent material to unfiltered seawater, and to demonstrate the system by evaluating the performance of adsorption material when it is exposed to natural marine biofouling as it would be when the technology is used in the marine environment. Exposures of amidoxime-based polymeric braid adsorbents prepared by Oak Ridge Natural Laboratory (ORNL) were exposed to ambient seawater at 20°C in a flume system. Adsorption kinetics and adsorption capacity were assessed using time series determinations of uranium adsorption and one-site ligand saturation modeling. Biofouling in sunlight surface seawater has the potential to significantly add substantial biogenic mass to adsorption material when it is exposed for periods greater than 21 days. The observed biomass increase in the light flume was approximately 80% of the adsorbent mass after 42 days

  2. Determination of Adsorption Capacity and Kinetics of Amidoxime-Based Uranium Adsorbent Braided Material in Unfiltered Seawater Using a Flume Exposure System

    Energy Technology Data Exchange (ETDEWEB)

    Gill, Gary A. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Kuo, Li-Jung [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Strivens, Jonathan E. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Park, Jiyeon [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Bonheyo, George T. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Jeters, Robert T. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Schlafer, Nicholas J. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Wood, Jordana R. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.

    2015-08-31

    PNNL has developed a recirculating flume system for exposing braided adsorbent material to natural seawater under realistic temperature and flow-rate exposure conditions. The flumes are constructed of transparent acrylic material; they allow external light to pass into the flumes and permit photosynthetic growth of naturally present marine organisms (biofouling). Because the system consists of two flumes, replicate experiments can be conducted in which one of the flumes can be manipulated relative to the other. For example, one flume can be darkened to eliminate light exposure by placing a black tarp over the flume such that dark/light experiments can be conducted. Alternatively, two different braided adsorbents can be exposed simultaneously with no potential cross contamination issues. This report describes the first use of the PNNL flume system to study the impact of biofouling on adsorbent capacity. Experiments were conducted with the ORNL AI8 braided adsorbent material in light-exposed and darkened flumes for a 42-day exposure experiment. The major objective of this effort is to develop a system for the exposure of braided adsorbent material to unfiltered seawater, and to demonstrate the system by evaluating the performance of adsorption material when it is exposed to natural marine biofouling as it would be when the technology is used in the marine environment. Exposures of amidoxime-based polymeric braid adsorbents prepared by Oak Ridge Natural Laboratory (ORNL) were exposed to ambient seawater at 20°C in a flume system. Adsorption kinetics and adsorption capacity were assessed using time series determinations of uranium adsorption and one-site ligand saturation modeling. Biofouling in sunlight surface seawater has the potential to significantly add substantial biogenic mass to adsorption material when it is exposed for periods greater than 21 days. The observed biomass increase in the light flume was approximately 80% of the adsorbent mass after 42 days

  3. Condition of granulating titanium-activated carbon composite adsorbent and its adsorption for uranium

    International Nuclear Information System (INIS)

    Miyai, Yoshitaka; Kitamura, Takao; Katoh, Shunsaku; Miyazaki, Hidetoshi

    1979-01-01

    The powdery titanium-activated carbon composite adsorbent was granulated, and the strength and uranium adsorptivity of the granulated adsorbent were studied in relation to its granulating condition. By use of polyvinylalcohol (PVA) with degree of polymerization above 2,000 as binder, the granular adsorbent with as much the same strength as commercial granular activated carbon was obtained. Addition of PVA did not affect the amount of adsorbed uranium in equilibrium, but decreased the adsorption rate. Effect of granule size between 2-5 mm on the uranium adsorption rate was that the uranium adsorption rate changed proportionally to surface area of assumed sphere. As a test for practical use, 5 times repetitions of adsorption and desorption were carried out on the same granular adsorbent. During this repetition the adsorbent containing formalized PVA revealed smaller weight loss than non-treated adsorbent. The amount of adsorbed uranium decreased with increasing repetition times, and reason of this was discussed. (author)

  4. Interstitial and adsorbed phosphates in shelf sediments off Visakhapatnam, east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma; Raju, G.R.K.

    Spatial distribution of interstitial and adsorbed phosphates in the shelf sediments shows an increasing trend with distance from coastal to inshore region. Maximum concentration ranges of interstitial and adsorbed phosphates are 16-19 and 40-50 mu g...

  5. All-fiber probe for optical coherence tomography with an extended depth of focus by a high-efficient fiber-based filter

    Science.gov (United States)

    Qiu, Jianrong; Shen, Yi; Shangguan, Ziwei; Bao, Wen; Yang, Shanshan; Li, Peng; Ding, Zhihua

    2018-04-01

    Although methods have been proposed to maintain high transverse resolution over an increased depth range, it is not straightforward to scale down the bulk-optic solutions to minimized probes of optical coherence tomography (OCT). In this paper, we propose a high-efficient fiber-based filter in an all-fiber OCT probe to realize an extended depth of focus (DOF) while maintaining a high transverse resolution. Mode interference in the probe is exploited to modulate the complex field with controllable radial distribution. The principle of DOF extension by the fiber-based filter is theoretically analyzed. Numerical simulations are conducted to evaluate the performances of the designed probes. A DOF extension ratio of 2.6 over conventional Gaussian beam is obtainable in one proposed probe under a focused beam diameter of 4 . 6 μm. Coupling efficiencies of internal interfaces of the proposed probe are below -40 dB except the last probe-air interface, which can also be depressed to be -44 dB after minor modification in lengths for the filter. Length tolerance of the proposed probe is determined to be - 28 / + 20 μm, which is readily satisfied in fabrication. With the merits of extended-DOF, high-resolution, high-efficiency and easy-fabrication, the proposed probe is promising in endoscopic applications.

  6. Adsorption removal of hydrogen sulfide gas. IV. Characteristics of adsorbents for the adsorption removal of hydrogen sulfide gas

    Energy Technology Data Exchange (ETDEWEB)

    Boki, K

    1974-10-25

    The amount of hydrogen sulfide gas adsorbed was affected by the surface properties (surface pH, acid strength, acid amount, and basic amount), the surface structure (pore volume), and the surface form (scanning electron microscopic observation) of 32 tested adsorbents. In general, the amount adsorption increased in the following order, amount of H/sub 2/S adsorbed on the silicate adsorbents, on the active carbon adsorbents, and on the zeolite adsorbents. The amount of H/sub 2/S adsorbed on magnesium silicate and silica gel adsorbents was mainly affected by the surface structure, and the amount adsorbed on the aluminum silicate adsorbents was affected by the distinctions on the surface forms of the adsorbents. The amount of H/sub 2/S adsorbed on 10 kinds of active carbon was determined by the surface properties and the surface structures of the adsorbents. The amount adsorbed on 12 kinds of zeolites was determined by either the surface properties or by the surface structures of the adsorbents. The amount of H/sub 2/S adsorbed on the silicate, active carbon, and zeolite adsorbents interacted with the heat of adsorption, and among the same kinds of adsorbents, the amount adsorbed was linearly related to the heat of adsorption.

  7. Competitive Adsorption of a Two-Component Gas on a Deformable Adsorbent

    OpenAIRE

    Usenko, A. S.

    2013-01-01

    We investigate the competitive adsorption of a two-component gas on the surface of an adsorbent whose adsorption properties vary in adsorption due to the adsorbent deformation. The essential difference of adsorption isotherms for a deformable adsorbent both from the classical Langmuir adsorption isotherms of a two-component gas and from the adsorption isotherms of a one-component gas taking into account variations in adsorption properties of the adsorbent in adsorption is obtained. We establi...

  8. Structural and functional characterization of proteins adsorbed on hydrophilized polylactide-co-glycolide microfibers

    Directory of Open Access Journals (Sweden)

    Vasita R

    2011-12-01

    Full Text Available Rajesh Vasita, Dhirendra S KattiDepartment of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, Uttar Pradesh, IndiaBackground: Hydrophobic biopolymers such as polylactide-co-glycolide (PLGA, 85:15 have been extensively explored as scaffolding materials for tissue engineering applications. More recently, electrospun microfiber-based and nanofiber-based scaffolds of PLGA have received increased attention because they act as physical mimics of the fibrillar extracellular matrix. However, the hydrophobicity of the PLGA microfiber surface can limit its use in biomedical applications. Therefore, in a previous study, we fabricated Pluronic® F-108 (PF-108-blended PLGA microfibrous scaffolds that alleviated the hydrophobicity associated with PLGA by enriching the surface of microfibers with the ethylene oxide units present in PF-108.Methods: In this study, we report the influence of the extent of surface enrichment of PLGA microfibers on their interaction with two model proteins, ie, bovine serum albumin (BSA and lysozyme. BSA and lysozyme were adsorbed onto PLGA microfiber meshes (unmodified and modified and studied for the amount, secondary structure conformation, and bioactivity of released protein.Results: Irrespective of the type of protein, PF-108-blended PLGA microfibers showed significantly greater protein adsorption and release than the unblended PLGA samples. However, in comparison with BSA, lysozyme showed a 7–9-fold increase in release. The Fourier transform infrared spectroscopy studies for secondary structure determination demonstrated that irrespective of type of microfiber surface (unblended or blended, adsorbed BSA and lysozyme did not show any significant change in secondary structure (α-helical content as compared with BSA and/or lysozyme in the free powder state. Further, the bioactivity assay of lysozyme released from blended PLGA microfiber meshes demonstrated 80%–85% bioactivity, indicating that

  9. Surface atomic relaxation and magnetism on hydrogen-adsorbed Fe(110) surfaces from first principles

    Science.gov (United States)

    Chohan, Urslaan K.; Jimenez-Melero, Enrique; Koehler, Sven P. K.

    2016-11-01

    We have computed adsorption energies, vibrational frequencies, surface relaxation and buckling for hydrogen adsorbed on a body-centred-cubic Fe(110) surface as a function of the degree of H coverage. This adsorption system is important in a variety of technological processes such as the hydrogen embrittlement in ferritic steels, which motivated this work, and the Haber-Bosch process. We employed spin-polarised density functional theory to optimise geometries of a six-layer Fe slab, followed by frozen mode finite displacement phonon calculations to compute Fe-H vibrational frequencies. We have found that the quasi-threefold (3f) site is the most stable adsorption site, with adsorption energies of ∼3.0 eV/H for all coverages studied. The long-bridge (lb) site, which is close in energy to the 3f site, is actually a transition state leading to the stable 3f site. The calculated harmonic vibrational frequencies collectively span from 730 to 1220 cm-1, for a range of coverages. The increased first-to-second layer spacing in the presence of adsorbed hydrogen, and the pronounced buckling observed in the Fe surface layer, may facilitate the diffusion of hydrogen atoms into the bulk, and therefore impact the early stages of hydrogen embrittlement in steels.

  10. Removal of heavy metals from emerging cellulosic low-cost adsorbents: a review

    Science.gov (United States)

    Malik, D. S.; Jain, C. K.; Yadav, Anuj K.

    2017-09-01

    Heavy metal pollution is a major problems in the environment. The impact of toxic metal ions can be minimized by different technologies, viz., chemical precipitation, membrane filtration, oxidation, reverse osmosis, flotation and adsorption. But among them, adsorption was found to be very efficient and common due to the low concentration of metal uptake and economically feasible properties. Cellulosic materials are of low cost and widely used, and very promising for the future. These are available in abundant quantity, are cheap and have low or little economic value. Different forms of cellulosic materials are used as adsorbents such as fibers, leaves, roots, shells, barks, husks, stems and seed as well as other parts also. Natural and modified types of cellulosic materials are used in different metal detoxifications in water and wastewater. In this review paper, the most common and recent materials are reviewed as cellulosic low-cost adsorbents. The elemental properties of cellulosic materials are also discussed along with their cellulose, hemicelluloses and lignin contents.

  11. Screening of active metals for reactive adsorption desulfurization adsorbent using density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lei; Zhao, Liang, E-mail: liangzhao@cup.edu.cn; Xu, Chunming; Wang, Yuxian; Gao, Jinsen

    2017-03-31

    Highlights: • Electronic characteristics determined adsorption characteristics of transition metals. • Cobalt has the similar adsorption ability of thiophene as nickel. • Adsorption capacity of Cr and Mo was extremely fierce, while Cu has the potential ability for adsorbing thiophene. • The preference adsorption site for thiophene was hollow site on all the seven surface. - Abstract: To explore characteristics of active metals for reactive adsorption desulfurization (RADS) technology, the adsorption of thiophene on M (100) (M = Cr, Mo, Co, Ni, Cu, Au, and Ag) surfaces was systematically studied by density functional theory with vdW correction (DFT + D3). We found that, in all case, the most stable molecular adsorption site was the hollow site and adsorptive capabilities of thiophene followed the order: Cr > Mo > Co ≈ Ni > Cu > Au ≈ Ag. By analyzing the nature of binding between thiophene and corresponding metals and the electronic structure of metals, the excessive activities of Cr and Mo were found to have a negative regeneration, the passive activities of Au and Ag were found to have an inactive adsorption for RADS adsorbent alone, while Ni and Co have appropriate characteristics as the active metals for RADS, followed by Cu.

  12. Selective Adsorption of Ethane over Ethylene in PCN-245: Impacts of Interpenetrated Adsorbent.

    Science.gov (United States)

    Lv, Daofei; Shi, Renfeng; Chen, Yongwei; Wu, Ying; Wu, Houxiao; Xi, Hongxia; Xia, Qibin; Li, Zhong

    2018-03-07

    The separation of ethane from ethylene using cryogenic distillation is an energy-intensive process in the industry. With lower energetic consumption, the adsorption technology provides the opportunities for developing the industry with economic sustainability. We report an iron-based metal-organic framework PCN-245 with interpenetrated structures as an ethane-selective adsorbent for ethylene/ethane separation. The material maintains stability up to 625 K, even after exposure to 80% humid atmosphere for 20 days. Adsorptive separation experiments on PCN-245 at 100 kPa and 298 K indicated that ethane and ethylene uptakes of PCN-245 were 3.27 and 2.39 mmol, respectively, and the selectivity of ethane over ethylene was up to 1.9. Metropolis Monte Carlo calculations suggested that the interpenetrated structure of PCN-245 created greater interaction affinity for ethane than ethylene through the crossing organic linkers, which is consistent with the experimental results. This work highlights the potential application of adsorbents with the interpenetrated structure for ethane separation from ethylene.

  13. Treatability of stabilize landfill leachate by using pressmud ash as an adsorbent

    Science.gov (United States)

    Azme, N. N. Mohd; Murshed, M. F.

    2018-04-01

    Leachate is a liquid produced from the landfill that contains high concentration of heavy metals, chemicals and nutrient loading. The treatability of these contaminants are complicated since the current treatment technology are costly and site specific. Therefore, this study was conducted to evaluate the treatability of stabilized landfill leachate by using waste (pressmud ash) as an absorbent. Pressmud ash was prepared by burning at different temperature from 100 to 700 degree Celsius and test at 24 hours shaking time, pH 8, and 4000 rpm. Leachate samples were collected from municipal solid waste (MSW) Pulau Burung Sanitary Landfill (PBSL) and were analyzed for heavy metal, COD, ammonia and colour. This study was performed in two phases i) leachate characteristic, ii) treatability assessment by using pressmud ash. Pressmud was sampled from the sugar mill, Malaysian Sugar Manufacturing (MSM) Sdn Bhd, Seberang Perai, Pulau Pinang. The pressmud with 400°C are highly potential material with a low cost which can be a good adsorbent was capable reducing efficiencies of COD (60.76%), ammonia (64.37%) and colour (35.78%) from real wastewater leachate. Pressmud showed good sorption capability. Surface modification with burning greatly enhanced the reducing efficiency of sugar waste based adsorbent with adsorption efficiency.

  14. Economical and ecological comparison of granular activated carbon (GAC) adsorber refill strategies.

    Science.gov (United States)

    Bayer, Peter; Heuer, Edda; Karl, Ute; Finkel, Michael

    2005-05-01

    Technical constraints can leave a considerable freedom in the design of a technology, production or service strategy. Choosing between economical or ecological decision criteria then characteristically leads to controversial solutions of ideal systems. For the adaptation of granular-activated carbon (GAC) fixed beds, various technical factors determine the adsorber volume required to achieve a desired service life. In considering carbon replacement and recycling, a variety of refill strategies are available that differ in terms of refill interval, respective adsorber volume, and time-dependent use of virgin, as well as recycled GAC. Focusing on the treatment of contaminant groundwater, we compare cost-optimal reactor configurations and refill strategies to the ecologically best alternatives. Costs and consumption of GAC are quantified within a technical-economical framework. The emissions from GAC production out of hard coal, transport and recycling are equally derived through a life cycle impact assessment. It is shown how high discount rates lead to a preference of small fixed-bed volumes, and accordingly, a high number of refills. For fixed discount rates, the investigation reveals that both the economical as well as ecological assessment of refill strategies are especially sensitive to the relative valuation of virgin and recycled GAC. Since recycling results in economic and ecological benefits, optimized systems thus may differ only slightly.

  15. Preparation of activated carbon from waste plastics polyethylene terephthalate as adsorbent in natural gas storage

    Science.gov (United States)

    Yuliusman; Nasruddin; Sanal, A.; Bernama, A.; Haris, F.; Ramadhan, I. T.

    2017-02-01

    The main problem is the process of natural gas storage and distribution, because in normal conditions of natural gas in the gas phase causes the storage capacity be small and efficient to use. The technology is commonly used Compressed Natural Gas (CNG) and Liquefied Natural Gas (LNG). The weakness of this technology safety level is low because the requirement for high-pressure CNG (250 bar) and LNG requires a low temperature (-161°C). It takes innovation in the storage of natural gas using the technology ANG (Adsorbed Natural Gas) with activated carbon as an adsorbent, causing natural gas can be stored in a low pressure of about 34.5. In this research, preparation of activated carbon using waste plastic polyethylene terephthalate (PET). PET plastic waste is a good raw material for making activated carbon because of its availability and the price is a lot cheaper. Besides plastic PET has the appropriate characteristics as activated carbon raw material required for the storage of natural gas because the material is hard and has a high carbon content of about 62.5% wt. The process of making activated carbon done is carbonized at a temperature of 400 ° C and physical activation using CO2 gas at a temperature of 975 ° C. The parameters varied in the activation process is the flow rate of carbon dioxide and activation time. The results obtained in the carbonization process yield of 21.47%, while the yield on the activation process by 62%. At the optimum process conditions, the CO2 flow rate of 200 ml/min and the activation time of 240 minutes, the value % burn off amounted to 86.69% and a surface area of 1591.72 m2/g.

  16. Use of sepiolite as an adsorbent for the removal of copper (II) from industrial waste leachate

    Science.gov (United States)

    Gamze Turan, N.; Ardali, Yüksel

    2013-04-01

    Land filling is the most common method of disposal of solid waste all over the world. As well as municipal solid waste, industrial wastes, which may contain hazardous substances, are also received by landfills in many countries. Leachate is one of the problems arising from landfills. When water percolates through solid wastes, contaminants are leached into solution. The major concern with the movement of leachate into the subsurface aquifer is the fate of the constituents found in leachate. The fate of heavy metals is the greatest interest in leachate. Several treatment technologies have been developed for eliminating heavy metals recently. Adsorption is one of the most interesting methods that it has been successfully applied for the heavy metal removal. Activated carbons were widely used as adsorbent materials because of their extended surface area, microporous structure, high adsorption capacity and high degree of surface reactivity. However, it is restricted due to its relatively high price, high operation costs, and problems with generation for the industrial scale applications. Recently, more research efforts have been focused on effective sorbents material in order to minimize the processing cost and solve their disposal problems in an environmentally sustainable way. Adsorption of metal ions onto clay minerals has been studied extensively because both metal ions and clays are common components in nature. The cost of clays is relatively low as compared to other alternative adsorbents. Furthermore, the high specific surface area, chemical and mechanical stability, variety of structural and surface properties and higher values of cation exchange capacities make the clays an excellent group of adsorbents. Sepiolite (Si12O30Mg8(OH)4(H2O)4•8H2O) is a natural, fibrous clay mineral with fine microporous channels running parallel to the length of the fibers. The structure of sepiolite, in some aspects, is similar to those of other 2:1 trioctahedral silicates, such

  17. Determination of Cr and Cd concentration adsorbed by chicken feathers

    International Nuclear Information System (INIS)

    Lopez M, A.; Cuapio O, L.A.; Cardenas P, S.; Balcazar, M.; Jauregui, V.; Bonilla P, A.

    2008-01-01

    In this work the results of the samples analysis of chicken feathers are presented, used as adsorber of the heavy metals Cd and Cr present in water solutions with well-known concentrations of these metals. It was used the Neutron Activation Analysis technique (AAN), using the TRIGA Mark-III reactor of the Nuclear Center of Mexico. The obtained results they show the advantages of having a versatile installation for the analysis of this type of samples. By means of the analysis of the results, it was determined the feasibility of using chicken feathers like adsorber of these metals present in polluted waters, additionally, it was detected the presence of others polluting elements in the inputs to prepare the reference solutions as well as in the processes, so much of preparation of the feathers like of the metals adsorption. (Author)

  18. Plant waste materials from restaurants as the adsorbents for dyes

    Directory of Open Access Journals (Sweden)

    Pavlović Marija D.

    2015-01-01

    Full Text Available This paper has demonstrated the valorization of inexpensive and readily available restaurant waste containing most consumed food and beverage residues as adsorbents for methylene blue dye. Coffee, tea, lettuce and citrus waste have been utilized without any pre-treatment, thus the adsorption capacities and dye removal efficiency were determined. Coffee waste showed highest adsorbent capacity, followed by tea, lettuce and citrus waste. The dye removal was more effective as dye concentration increases from 5 up to 60 mg/L. The favorable results obtained for lettuce waste have been especially encouraged, as this material has not been commonly employed for sorption purposes. Equilibrium data fitted very well in a Freundlich isotherm model, whereas pseudo-second-order kinetic model describes the process behavior. Restaurant waste performed rapid dye removal at no cost, so it can be adopted and widely used in industries for contaminated water treatment.

  19. Topological features of engineered arrays of adsorbates in honeycomb lattices

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Arraga, Luis A., E-mail: ludovici83@gmail.com [IMDEA Nanociencia, Calle de Faraday, 9, Cantoblanco, 28049 Madrid (Spain); Lado, J.L. [International Iberian Nanotechnology Laboratory (INL), Av. Mestre Jose Veiga, 4715-330 Braga (Portugal); Guinea, Francisco [IMDEA Nanociencia, Calle de Faraday, 9, Cantoblanco, 28049 Madrid (Spain); School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom)

    2016-09-01

    Hydrogen adatoms are one of the most the promising proposals for the functionalization of graphene. The adatoms induce narrow resonances near the Dirac energy, which lead to the formation of magnetic moments. Furthermore, they also create local lattice distortions which enhance the spin–orbit coupling. The combination of magnetism and spin–orbit coupling allows for a rich variety of phases, some of which have non-trivial topological features. We analyze the interplay between magnetism and spin–orbit coupling in ordered arrays of adsorbates on honeycomb lattice monolayers, and classify the different phases that may arise. We extend our model to consider arrays of adsorbates in graphene-like crystals with stronger intrinsic spin–orbit couplings. We also consider a regime away from half-filling in which the Fermi level is at the bottom of the conduction band, we find a Berry curvature distribution corresponding to a Valley–Hall effect.

  20. pyIAST: Ideal adsorbed solution theory (IAST) Python package

    Science.gov (United States)

    Simon, Cory M.; Smit, Berend; Haranczyk, Maciej

    2016-03-01

    Ideal adsorbed solution theory (IAST) is a widely-used thermodynamic framework to readily predict mixed-gas adsorption isotherms from a set of pure-component adsorption isotherms. We present an open-source, user-friendly Python package, pyIAST, to perform IAST calculations for an arbitrary number of components. pyIAST supports several common analytical models to characterize the pure-component isotherms from experimental or simulated data. Alternatively, pyIAST can use numerical quadrature to compute the spreading pressure for IAST calculations by interpolating the pure-component isotherm data. pyIAST can also perform reverse IAST calculations, where one seeks the required gas phase composition to yield a desired adsorbed phase composition.

  1. New apparatus for measuring radon adsorption on solid adsorbents

    International Nuclear Information System (INIS)

    Hassan, N.M.; Hines, A.L.; Ghosh, T.K.; Loyalka, S.K.; Ketring, A.R.

    1991-01-01

    A new experimental system was designed to measure radon uptake by solid adsorbents from air or other carrier gases/vapors. The total amount of radon adsorbed corresponding to a specific gas-phase concentration was determined by simultaneously measuring the solid-phase and gas-phase concentrations. The system was used to measure radon adsorption isotherms on BPL activated carbon at 288, 298, and 308 K and on silica gel and molecular sieve 13X at 298 K. The isotherms were of type III according to Brunauer's classification. The heat of adsorption data indicated that the BPL activated carbon provided a heterogeneous surface for radon adsorption. The equilibrium data were correlated by the Freundlich equation. In this paper the possible adsorption mechanism and the use of the adsorption isotherms to measure indoor radon concentrations are discussed

  2. Ozonation of isoproturon adsorbed on silica particles under atmospheric conditions

    Science.gov (United States)

    Pflieger, Maryline; Grgić, Irena; Kitanovski, Zoran

    2012-12-01

    The results on heterogeneous ozonation of a phenylurea pesticide, isoproturon, under atmospheric conditions are presented for the first time in the present study. The study was carried out using an experimental device previously adopted and validated for the heterogeneous reactivity of organics toward ozone (Pflieger et al., 2011). Isoproturon was adsorbed on silica particles via a liquid-to-solid equilibrium with a load far below a monolayer (0.02% by weight/surface coverage of 0.5%). The rate constants were estimated by measuring the consumption of the organic (dark, T = 26 °C, RH isoproturon on the aerosol surface does not affect the kinetics of ozonation, indicating that both compounds are adsorbed on different surface sites of silica particles.

  3. Radiolysis of alanine adsorbed in a clay mineral

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Ovando, Ellen Y.; Negron-Mendoza, Alicia [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico (UNAM), Circuito Exterior s/n, Ciudad Universitaria, Apartado Postal 70-543, Deleg. Coyoacan, C.P. 04510 (Mexico)

    2013-07-03

    Optical activity in molecules is a chemical characteristic of living beings. In this work, we examine the hypothesis of the influence of different mineral surfaces on the development of a specific chirality in organic molecules when subjected to conditions simulating the primitive Earth during the period of chemical evolution. By using X-ray diffraction techniques and HPLC/ELSD to analyze aqueous suspensions of amino acids adsorbed on minerals irradiated in different doses with a cobalt-60 gamma source, the experiments attempt to prove the hypothesis that some solid surfaces (like clays and meteorite rocks) may have a concentration capacity and protective role against external sources of ionizing radiation (specifically {gamma}-ray) for some organic compounds (like some amino acids) adsorbed on them. Preliminary results show a slight difference in the adsorption and radiolysis of the D-and L-alanine.

  4. Radiolysis of alanine adsorbed in a clay mineral

    International Nuclear Information System (INIS)

    Aguilar-Ovando, Ellen Y.; Negrón-Mendoza, Alicia

    2013-01-01

    Optical activity in molecules is a chemical characteristic of living beings. In this work, we examine the hypothesis of the influence of different mineral surfaces on the development of a specific chirality in organic molecules when subjected to conditions simulating the primitive Earth during the period of chemical evolution. By using X-ray diffraction techniques and HPLC/ELSD to analyze aqueous suspensions of amino acids adsorbed on minerals irradiated in different doses with a cobalt-60 gamma source, the experiments attempt to prove the hypothesis that some solid surfaces (like clays and meteorite rocks) may have a concentration capacity and protective role against external sources of ionizing radiation (specifically γ-ray) for some organic compounds (like some amino acids) adsorbed on them. Preliminary results show a slight difference in the adsorption and radiolysis of the D-and L-alanine

  5. A Method for Field Calibration of the PA260 Phosphorus Analyzer Using Solid Adsorbent Materials

    Science.gov (United States)

    1989-12-01

    plant environment. The solid adsorbent approach has two major advantages over other traditional air sampling devices such as bubblers or impingers...GC (60/80 mesh) or Chromosorb 106 (80/100 mesh). Both adsorbents were supplied by Alltech Associates (Deerfield, IL). The adsorbents were packed in

  6. Performance of adsorbent-embedded heat exchangers using binder-coating method

    KAUST Repository

    Li, Ang; Thu, Kyaw; Ismail, Azhar Bin; Shahzad, Muhammad Wakil; Ng, Kim Choon

    2016-01-01

    The performance of adsorption (AD) chillers or desalination cycles is dictated by the rates of heat and mass transfer of adsorbate in adsorbent-packed beds. Conventional granular-adsorbent, packed in fin-tube heat exchangers, suffered from poor heat

  7. Single stage batch adsorber design for efficient Eosin yellow removalby polyaniline coated ligno-cellulose

    CSIR Research Space (South Africa)

    Debnath, S

    2015-01-01

    Full Text Available Polyaniline-coated lignin-based adsorbent (PLC) was synthesized and used for uptake of reactive dye eosin yellow (EY) from aqueous solution. The adsorption capability of the adsorbent was found to be more effective than the unmodified adsorbent (LC...

  8. An innovative zinc oxide-coated zeolite adsorbent for removal of humic acid

    Science.gov (United States)

    Zinc oxide (ZnO)-coated zeolite adsorbents were developed by both nitric acid modification and Zn(NO3)2•6H2O functionalization of zeolite. The developed adsorbents were used for the removal of humic acid (HA) from aqueous solutions. The adsorption capacity of the adsorbents at 21...

  9. Infrared Analysis Of Enzymes Adsorbed Onto Model Surfaces

    Science.gov (United States)

    Story, Gloria M.; Rauch, Deborah S.; Brode, Philip F.; Marcott, Curtis A.

    1989-12-01

    The adsorption of the enzymes, subtilisin BPN' and lysozyme, onto model surfaces was examined using attenuated total reflectance (ATR) infrared (IR) spectroscopy. Using a cylindrical internal reflection (CIRcle) cell with a Germanium (Ge) internal reflection element (IRE), model hydrophilic surfaces were made by plasma cleaning the IRE and model hydrophobic surfaces were made by precoating the IRE with a thin film of polystyrene. Gas chromatography (GC)-IR data collection software was used to monitor adsorption kinetics during the first five minutes after injection of the enzyme into the CIRcle cell. It was found that for both lysozyme and BPN', most of the enzyme that was going to adsorb onto the model surface did so within ten seconds after injection. Nearly an order-of-magnitude more BPN' adsorbed on the hydrophobic Ge surface than the hydrophilic one, while lysozyme adsorbed somewhat more strongly to the hydrophilic Ge surface. Overnight, the lysozyme layer continued to increase in thickness, while BPN' maintained its initial coverage. The appearance of carboxylate bands in some of the adsorbed BPN' spectra suggests the occurrence of peptide bond hydrolysis. A Au/Pd coating on the CIRcle cell o-rings had a significant effect on the adsorption of BPN'. (This coating was applied in an attempt to eliminate interfering Teflon absorption bands.) An apparent electrochemical reaction occurred, involving BPN', Ge, Au/Pd, and the salt solution used to stabilize BPN'. The result of this reaction was enhanced adsorption of the enzyme around the coated o-rings, etching of the Ge IRE at the o-ring site, and some autolysis of the enzyme. No such reaction was observed with lysozyme.

  10. Removal of toxic industrial chemicals using novel adsorbent hollow fibres

    OpenAIRE

    Jeffs, Corinne

    2015-01-01

    The current military respirator provides protection from contaminants using a cartridge packed with adsorbent activated carbon particles treated with metal salts to provide protection from toxic gases. However, the user of this respirator is subject to a physiological burden as a result. One component of this burden is the pressure drop, which makes breathing through the respirator filter difficult, with the burden becoming more severe at higher breathing rates. This project investigates the ...

  11. Iodine-adsorbent poisoning: FY-82 summary report

    International Nuclear Information System (INIS)

    Jolley, J.G.; Casper, L.A.

    1982-10-01

    Along with its positive attributes as an adsorbent of radioiodine in nuclear plant air cleaning systems, silver zeolite has the disadvantage of being susceptible to poisoning. (Poisoning is defined as the reduction of efficiency in radioiodine removal.) In view of the gravimetric and infrared spectroscopy data presented, π-bonded hydrocarbons, oxygenated organics, and halocarbons appear to be probable poisons of a silver zeolite filtration system

  12. Scattering of atoms by molecules adsorbed at solid surfaces

    International Nuclear Information System (INIS)

    Parra, Zaida.

    1988-01-01

    The formalism of collisional time-correlation functions, appropriate for scattering by many-body targets, is implemented to study energy transfer in the scattering of atoms and ions from molecules adsorbed on metal surfaces. Double differential cross-sections for the energy and angular distributions of atoms and ions scattered by a molecule adsorbed on a metal surface are derived in the limit of impulsive collisions and within a statistical model that accounts for single and double collisions. They are found to be given by the product of an effective cross-section that accounts for the probability of deflection into a solid angle times a probability per unit energy transfer. A cluster model is introduced for the vibrations of an adsorbed molecule which includes the molecular atoms, the surface atoms binding the molecule, and their nearest neighbors. The vibrational modes of CO adsorbed on a Ni(001) metal surface are obtained using two different cluster models to represent the on-top and bridge-bonding situations. A He/OC-Ni(001) potential is constructed from a strongly repulsive potential of He interacting with the oxygen atom in the CO molecule and a van der Waals attraction accounting for the He interaction with the free Ni(001) surface. A potential is presented for the Li + /OC-Ni(001) where a coulombic term is introduced to account for the image force. Trajectory studies are performed and analyzed in three dimensions to obtain effective classical cross-sections for the He/OC-Ni(001) and Li + /OC-Ni(001) systems. Results for the double differential cross-sections are presented as functions of scattering angles, energy transfer and collisional energy. Temperature dependence results are also analyzed. Extensions of the approach and inclusion of effects such as anharmonicity, collisions at lower energies, and applications of the approach to higher coverages are discussed

  13. Non-linear optical studies of adsorbates: Spectroscopy and dynamics

    International Nuclear Information System (INIS)

    Zhu, Xiangdong.

    1989-08-01

    In the first part of this thesis, we have established a systematic procedure to apply the surface optical second-harmonic generation (SHG) technique to study surface dynamics of adsorbates. In particular, we have developed a novel technique for studies of molecular surface diffusions. In this technique, the laser-induced desorption with two interfering laser beams is used to produce a monolayer grating of adsorbates. The monolayer grating is detected with diffractions of optical SHG. By monitoring the first-order second-harmonic diffraction, we can follow the time evolution of the grating modulation from which we are able to deduce the diffusion constant of the adsorbates on the surface. We have successfully applied this technique to investigate the surface diffusion of CO on Ni(111). The unique advantages of this novel technique will enable us to readily study anisotropy of a surface diffusion with variable grating orientation, and to investigate diffusion processes of a large dynamic range with variable grating spacings. In the second part of this work, we demonstrate that optical infrared-visible sum-frequency generation (SFG) from surfaces can be used as a viable surface vibrational spectroscopic technique. We have successfully recorded the first vibrational spectrum of a monolayer of adsorbates using optical infrared-visible SFG. The qualitative and quantitative correlation of optical SFG with infrared absorption and Raman scattering spectroscopies are examined and experimentally demonstrated. We have further investigated the possibility to use transient infrared-visible SFG to probe vibrational transients and ultrafast relaxations on surfaces. 146 refs

  14. Non-linear optical studies of adsorbates: Spectroscopy and dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiangdong.

    1989-08-01

    In the first part of this thesis, we have established a systematic procedure to apply the surface optical second-harmonic generation (SHG) technique to study surface dynamics of adsorbates. In particular, we have developed a novel technique for studies of molecular surface diffusions. In this technique, the laser-induced desorption with two interfering laser beams is used to produce a monolayer grating of adsorbates. The monolayer grating is detected with diffractions of optical SHG. By monitoring the first-order second-harmonic diffraction, we can follow the time evolution of the grating modulation from which we are able to deduce the diffusion constant of the adsorbates on the surface. We have successfully applied this technique to investigate the surface diffusion of CO on Ni(111). The unique advantages of this novel technique will enable us to readily study anisotropy of a surface diffusion with variable grating orientation, and to investigate diffusion processes of a large dynamic range with variable grating spacings. In the second part of this work, we demonstrate that optical infrared-visible sum-frequency generation (SFG) from surfaces can be used as a viable surface vibrational spectroscopic technique. We have successfully recorded the first vibrational spectrum of a monolayer of adsorbates using optical infrared-visible SFG. The qualitative and quantitative correlation of optical SFG with infrared absorption and Raman scattering spectroscopies are examined and experimentally demonstrated. We have further investigated the possibility to use transient infrared-visible SFG to probe vibrational transients and ultrafast relaxations on surfaces. 146 refs.

  15. CHEMICAL REACTIONS ON ADSORBING SURFACE: KINETIC LEVEL OF DESCRIPTION

    Directory of Open Access Journals (Sweden)

    P.P.Kostrobii

    2003-01-01

    Full Text Available Based on the effective Hubbard model we suggest a statistical description of reaction-diffusion processes for bimolecular chemical reactions of gas particles adsorbed on the metallic surface. The system of transport equations for description of particles diffusion as well as reactions is obtained. We carry out the analysis of the contributions of all physical processes to the formation of diffusion coefficients and chemical reactions constants.

  16. Removal of arsenic from drinking water by natural adsorbents

    OpenAIRE

    MD SHAHNOOR ALAM KHAN

    2017-01-01

    The presence of arsenic in groundwater has been reported in many countries across the world and it is a serious threat to public health. The aim of this study was to identify prospective natural materials with high arsenic adsorption capacity and durable hydraulic property to produce adequate flow of water. The comparative study identified Skye sand as the best natural adsorbent. The prototype household filter with Skye sand achieved complete removal of arsenic and iron. Arsenic removal by du...

  17. Heat capacity of xenon adsorbed in nanobundle grooves

    International Nuclear Information System (INIS)

    Chishko, K.A.; Sokolova, E.S.

    2016-01-01

    A model of one-dimensional real gas under external transverse force field is applied to interpret the experimentally observed thermodynamical properties of xenon deposited into groves on the surface of carbon nanobundles. This non-ideal gas model with pair interaction is not quite adequate to describe the dense adsorbates (especially at low temperature limit), but it makes possible to take into account easily the particle exchange between 1D adsorbate and 3D atmosphere which becomes an essential factor since intermediate (for xenon - of order 35 K) up to high (approx 100 K) temperatures. In this paper we treat the 1D real gas with only Lennard-Jones pair interaction, but at presence of exact equilibrium conditions on the atom numbers between low-dimensional adsorbate and three-dimensional atmosphere of the experimental cell. The low-temperature branch of the heat capacity has been fitted separately within the elastic atomic chain model to get the best agreement between theory and experiment in as wide as possible region just from zero temperature. The gas approximation is introduced from the temperatures where the chain heat capacity tends definitely to 1D equipartition law. In this case the principal parameters for both models can be chosen in such a way that the heat capacity C(T) of the chain goes continuously into the corresponding curve of the gas approximation. So, it seems to be expected that adequate interpretation for temperature dependences of the atomic adsorbate heat capacity can be obtained through a reasonable combination of 1D gas and phonon approaches. The principal parameters of the gas approximation (such a desorption energy) found from the fitting between theory and experiment for xenon heat capacity are in good agreement with corresponding data known in literature.

  18. Characterization of fractals with an adsorbed superfluid film

    International Nuclear Information System (INIS)

    Golov, A.I.; Berkutov, I.B.; Babuin, S.; Cousins, D.J.

    2003-01-01

    The tortuosity of a capillary-condensed film of superfluid 4 He adsorbed on 91%-porous silica aerogel has been measured, with transverse sound, as a function of helium coverage. Complementary data from 4 He adsorption isotherms and small-angle X-ray scattering have also been used for substrate characterization. The tortuosity is found to be roughly inversely proportional to the volume fraction of the liquid phase of helium

  19. Toxicity of Uranium Adsorbent Materials using the Microtox Toxicity Test

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jiyeon [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jeters, Robert T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gill, Gary A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kuo, Li-Jung [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bonheyo, George T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-10-01

    The Marine Sciences Laboratory at the Pacific Northwest National Laboratory evaluated the toxicity of a diverse range of natural and synthetic materials used to extract uranium from seawater. The uranium adsorbent materials are being developed as part of the U. S. Department of Energy, Office of Nuclear Energy, Fuel Resources Program. The goal of this effort was to identify whether deployment of a farm of these materials into the marine environment would have any toxic effects on marine organisms.

  20. Adsorbate-driven cooling of carbene-based molecular junctions

    Czech Academy of Sciences Publication Activity Database

    Foti, Giuseppe; Vázquez, Héctor

    2017-01-01

    Roč. 8, Oct (2017), s. 2060-2068 ISSN 2190-4286 R&D Projects: GA ČR GA15-19672S EU Projects: European Commission(XE) 702114 - HEATEXMOL Institutional support: RVO:68378271 Keywords : adsorbate * carbene * current-induced heating and cooling * molecular junction * vibrations Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.127, year: 2016

  1. Linear response theory of activated surface diffusion with interacting adsorbates

    Energy Technology Data Exchange (ETDEWEB)

    Marti' nez-Casado, R. [Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ (United Kingdom); Sanz, A.S.; Vega, J.L. [Instituto de Fi' sica Fundamental, Consejo Superior de Investigaciones Cientificas, Serrano 123, 28006 Madrid (Spain); Rojas-Lorenzo, G. [Instituto Superior de Tecnologi' as y Ciencias Aplicadas, Ave. Salvador Allende, esq. Luaces, 10400 La Habana (Cuba); Instituto de Fi' sica Fundamental, Consejo Superior de Investigaciones Cienti' ficas, Serrano 123, 28006 Madrid (Spain); Miret-Artes, S., E-mail: s.miret@imaff.cfmac.csic.es [Instituto de Fi' sica Fundamental, Consejo Superior de Investigaciones Cienti' ficas, Serrano 123, 28006 Madrid (Spain)

    2010-05-12

    Graphical abstract: Activated surface diffusion with interacting adsorbates is analyzed within the Linear Response Theory framework. The so-called interacting single adsorbate model is justified by means of a two-bath model, where one harmonic bath takes into account the interaction with the surface phonons, while the other one describes the surface coverage, this leading to defining a collisional friction. Here, the corresponding theory is applied to simple systems, such as diffusion on flat surfaces and the frustrated translational motion in a harmonic potential. Classical and quantum closed formulas are obtained. Furthermore, a more realistic problem, such as atomic Na diffusion on the corrugated Cu(0 0 1) surface, is presented and discussed within the classical context as well as within the framework of Kramer's theory. Quantum corrections to the classical results are also analyzed and discussed. - Abstract: Activated surface diffusion with interacting adsorbates is analyzed within the Linear Response Theory framework. The so-called interacting single adsorbate model is justified by means of a two-bath model, where one harmonic bath takes into account the interaction with the surface phonons, while the other one describes the surface coverage, this leading to defining a collisional friction. Here, the corresponding theory is applied to simple systems, such as diffusion on flat surfaces and the frustrated translational motion in a harmonic potential. Classical and quantum closed formulas are obtained. Furthermore, a more realistic problem, such as atomic Na diffusion on the corrugated Cu(0 0 1) surface, is presented and discussed within the classical context as well as within the framework of Kramer's theory. Quantum corrections to the classical results are also analyzed and discussed.

  2. Rotary adsorbers for waste air purification and solvent recovery

    International Nuclear Information System (INIS)

    Konrad, G.; Eigenberger, G.

    1994-01-01

    Rotary Adsorbers for Waste Air Purification and Solvent Recovery. Thanks to their compact construction and low pressure drops, adsorbers with rotating adsorbent beds are highly suitable both for retrofitting of waste air purification units and generally for the removal of absorbable components from gas streams. When used in conjunction with straightforward hot gas desorption they permit almost complete purification of gas flows with concomitant concentration of the separated components in the desorbate by a factor of 10 to 20. They can also be used in conjunction with recovery of the separated components by partial condensation of the desorbate. Owing to the fixed coupling of adsorption and desorption times, which is determined by the geometry of the unit, the behaviour of the system is distinctly different from that of conventional multiple bed systems in cyclic operation. A detailed model description and computer simulation of operating behaviour are particularly useful for their analysis. It is shown that the behaviour of commercially available rotor concepts can be much better understood in this way and new concepts for exhaust air purification with integrated solvent recovery can be developed which are characterised by significantly reduced energy requirements for desorption and condensation. (orig.) [de

  3. Specific binding-adsorbent assay method and test means

    International Nuclear Information System (INIS)

    1981-01-01

    A description is given of an improved specific binding assay method and test means employing a nonspecific adsorbent for the substance to be determined, particularly hepatitis B surface (HBsub(s)) antigen, in its free state or additionally in the form of its immune complex. The invention is illustrated by 1) the radioimmunoadsorbent assay for HBsub(s) antigen, 2) the radioimmunoadsorbent assay for HBsub(s) antigen in the form of immune complex with antibody, 3) a study of adsorption characteristics of various anion exchange materials for HBsub(s) antigen, 4) the use of hydrophobic adsorbents in a radioimmunoadsorbent assay for HBsub(s) antigen and 5) the radioimmunoadsorbent assay for antibody to HBsub(s) antigen. The advantages of the present method for detecting HBsub(s) antigen compared to previous methods include the manufacturing advantages of eliminating the need for insolubilised anti-HBsub(s) and the advantages of a single incubation step, fewer manipulations, storability of adsorbent materials, increased sensitivity and versatility of detecting HBsub(s) antigen in the form of its immune complex if desired. (U.K.)

  4. Interaction of atomic hydrogen with ethylene adsorbed on nickel films

    International Nuclear Information System (INIS)

    Korchak, V.N.; Tret'yakov, I.I.; Kislyuk, M.U.

    1976-01-01

    The reactivity of ethylene adsorbed on the pure films of nickel at various temperatures was studied with respect to hydrogen atoms generated in the gaseous phase. The experiments were conducted in a glass vacuum apparatus enabling one to obtain the highest vacuum up to 2x20 -10 torr. The catalyst, nickel films, was produced by their deposition onto the walls of the glass reactor at a pressure of the residual gas of 10 -9 torr and a temperature of the walls of 25 deg C. Gas purity was analyzed by the mass spectrometric method. The ethylene adsorbed at the temperatures below 173 deg K reacted readily with the hydrogen atoms to yield ethane. The process ran without practically any activation energy involved and was limited by the attachment of the first hydrogen atom to the ethylene molecule. The efficiency of this interaction was 0.02 of the number of the hydrogen atoms collisions against the surface occupied by the ethylene. The adsorption of the ethylene at room and higher temperatures was accompanied by its disproportioning with the release of the hydrogen into the gaseous phase and a serious destruction of the ethylene molecules adsorbed to produce hydrogen residues interacting with neither molecular nor atomic hydrogen [ru

  5. Distribution of metal and adsorbed guest species in zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Chmelka, B.F.

    1989-12-01

    Because of their high internal surface areas and molecular-size cavity dimensions, zeolites are used widely as catalysts, shape- selective supports, or adsorbents in a variety of important chemical processes. For metal-catalyzed reactions, active metal species must be dispersed to sites within the zeolite pores that are accessible to diffusing reactant molecules. The distribution of the metal, together with transport and adsorption of reactant molecules in zeolite powders, are crucial to ultimate catalyst performance. The nature of the metal or adsorbed guest distribution is known, however, to be dramatically dependent upon preparatory conditions. Our objective is to understand, at the molecular level, how preparatory treatments influence the distribution of guest species in zeolites, in order that macroscopic adsorption and reaction properties of these materials may be better understood. The sensitivity of xenon to its adsorption environment makes {sup 129}Xe NMR spectroscopy an important diagnostic probe of metal clustering and adsorbate distribution processes in zeolites. The utility of {sup 129}Xe NMR depends on the mobility of the xenon atoms within the zeolite-guest system, together with the length scale of the sample heterogeneity being studied. In large pore zeolites containing dispersed guest species, such as Pt--NaY, {sup 129}Xe NMR is insensitive to fine structural details at room temperature.

  6. Stochastic Description of Activated Surface Diffusion with Interacting Adsorbates

    Science.gov (United States)

    Martínez-Casado, Ruth; Vega, José Luis; Sanz, Ángel S.; Miret-Artés, Salvador

    Activated surface diffusion on metal surfaces is receiving much attention both experimentally and theoretically. One of the main theoretical problems in this field is to explain the line-shape broadening observed when the surface coverage is increased. Recently, we have proposed a fully stochastic model, the interacting single adsorbate (ISA) model, aimed at explaining and understanding this type of experiments, which essentially consists of considering the classical Langevin formulation with two types of noise forces: (i) a Gaussian white noise accounting for the substrate friction, and (ii) a shot noise simulating the interacting adsorbates at different coverages. No interaction potential between adsorbates is included because any trace of microscopic interaction seems to be wiped out in a Markovian regime. This model describes in a good approximation, and at a very low computational cost, the line-shape broadening observed experimentally. Furthermore, its mathematical simplicity also allows to derive some analytical expressions which are of much help in the interpretation of the physics underlying surface diffusion processes.

  7. Shrimp pond wastewater treatment using pyrolyzed chicken feather as adsorbent

    Science.gov (United States)

    Moon, Wei Chek; Jbara, Mohamad Hasan; Palaniandy, Puganeshwary; Yusoff, Mohd Suffian

    2017-10-01

    In this study, chicken feather fiber was used as a raw material to prepare a non-expensive adsorbent by pyrolysis without chemical activation. The main pollutants treated in this study were chemical oxygen demand (COD) and ammoniacal nitrogen (NH3-N) from shrimp pond wastewater containing high concentrations of nutrients, which caused the eutrophication phenomenon in adjacent water. Batch adsorption studies were performed to investigate the effect of pH (5-8), mass of adsorbent (0.5-3 g), and shaking time (0.5-2 h) on the removal efficiency of COD and NH3- N. Experimental results showed that the optimum conditions were as follows: pH 5, 0.5 g of adsorbent, and 0.5 h of shaking. Under these conditions, 34.01% and 40.47% of COD and NH3-N were removed, respectively, from shrimp pond wastewater. The adsorption processes were best described by the Langmuir isotherm model for COD and NH3-N removal, with maximum monolayer adsorption capacity of 36.9 and 7.24 mg/g for COD and NH3-N, respectively. The results proved that chicken feather could remove COD and NH3-N from shrimp pond wastewater. However, further studies on thermal treatment should be carried out to increase the removal efficiency of pyrolyzed chicken feather fiber.

  8. Distribution of metal and adsorbed guest species in zeolites

    International Nuclear Information System (INIS)

    Chmelka, B.F.

    1989-12-01

    Because of their high internal surface areas and molecular-size cavity dimensions, zeolites are used widely as catalysts, shape- selective supports, or adsorbents in a variety of important chemical processes. For metal-catalyzed reactions, active metal species must be dispersed to sites within the zeolite pores that are accessible to diffusing reactant molecules. The distribution of the metal, together with transport and adsorption of reactant molecules in zeolite powders, are crucial to ultimate catalyst performance. The nature of the metal or adsorbed guest distribution is known, however, to be dramatically dependent upon preparatory conditions. Our objective is to understand, at the molecular level, how preparatory treatments influence the distribution of guest species in zeolites, in order that macroscopic adsorption and reaction properties of these materials may be better understood. The sensitivity of xenon to its adsorption environment makes 129 Xe NMR spectroscopy an important diagnostic probe of metal clustering and adsorbate distribution processes in zeolites. The utility of 129 Xe NMR depends on the mobility of the xenon atoms within the zeolite-guest system, together with the length scale of the sample heterogeneity being studied. In large pore zeolites containing dispersed guest species, such as Pt--NaY, 129 Xe NMR is insensitive to fine structural details at room temperature

  9. Treatment of Refinery Waste Water Using Environmental Friendly Adsorbent

    Science.gov (United States)

    Devi, M. Geetha; Al-Moshrafi, Samira Mohammed Khamis; Al Hudaifi, Alaa; Al Aisari, Buthaina Hamood

    2017-12-01

    This research evaluates the effectiveness of activated carbon prepared from walnut shell in the removal of pollutants from refinery waste water by adsorption technique. A series of batch experiments were carried out by varying the effluent solution pH, stirring time, stirring speed and adsorbent dosage in the reduction of pollutants from refinery effluent. Characterization of the adsorbent was performed using Scanning Electron Microscopy (SEM), Brunauer Emmett and Teller (BET) isotherm and Fourier Transform Infrared (FTIR) Spectroscopy. The best quality activated carbon was obtained with a particle size of 0.75 µm, activation temperature of 800 °C and activation time 24 h. The maximum BET surface area obtained was 165.2653 m2/g. The experimental results demonstrates that the highest percentage reduction in COD was 79%, using 0.6 g walnut shell powder at an optimum stirring speed of 100 rpm, at pH 6 and 120 min of contact time. The outcome of the result shows that walnut shell carbon is a potentially useful adsorbent for the removal of pollutants from refinery waste water.

  10. Cu II Removal from Industrial Wastewater Using Low Cost Adsorbent

    Directory of Open Access Journals (Sweden)

    Salwa Hadi Ahmed

    2018-01-01

    Full Text Available Study the possibility of utilization of waste tires rubber ash (WTRA as a low-cost adsorbent and are available as a type of solid waste for the removal of copper ions from industrial wastewater. Depending on batch adsorption experiments, the effect of different parameters including pH, adsorbent dosage WTRA, contact time, initial concentration of the ion and shacking speed were studied. Results showed that the highest removal Cu+2 ions was 97.8% at pH equal to 6, 120 min contact time, dose WTRA 1.5 g/L, shacking speed 150 rpm. The experimental data were analyzed using the Freundlich and Langmuir isotherm models showed great compatibility with Langmuir model (R2=0.923. Adsorption kinetics was studied and the data was showed agree with Pseudo-first-order equation where the value of (kt=0.5115/min. The study also showed the possibility of using WTRA efficiently as adsorbent and low cost in the removal of copper ions from industrial waste water. DOI: http://dx.doi.org/10.25130/tjes.24.2017.17

  11. Study of Adsorbents for the Capture of CO2 in Post-combustion. Contribution of CIEMAT to Module 4 of the CENITCO2 Project

    International Nuclear Information System (INIS)

    Ruiz, E.; Marono, M.; Sanchez-Hervas, J. M.

    2010-01-01

    The main goal of CIEMAT within the CENIT-CO 2 project has been the development of a process for CO 2 capture from combustion flue gases by physical adsorption. In the first stage, screening studies to select promising adsorbents were carried out at laboratory scale, using simplified gas compositions. After that, pilot plant studies were performed using appropriate configurations of promising adsorbents under realistic conditions. CO 2 adsorption cyclic capacity of different adsorbents has been studied. Lastly, for the adsorbent selected as most promising, its cyclic efficiency and selectivity for CO 2 adsorption in the presence of other gaseous components (SO 2 , H 2 O, NO) of the combustion gas has been determined, as well as its performance along multiple sorption-desorption cycles in the presence of simulated combustion gas. None of the studied adsorbents, though being promising since they all have a capture efficiency of about 90%, seem to be susceptible of direct application to CO 2 capture by physical adsorption under conditions representative of gases exiting the desulphurization tower of conventional pulverized coal combustion plants. As an alternative, the development of hybrid and regenerable solid sorbents (physical-chemical adsorption) is proposed or the application of new technologies under development such as the electrochemical promotion in capturing CO 2 . (Author) 33 refs.

  12. 13C NMR and XPS characterization of anion adsorbent with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse

    Science.gov (United States)

    Cao, Wei; Wang, Zhenqian; Zeng, Qingling; Shen, Chunhua

    2016-12-01

    Despite amino groups modified crop straw has been intensively studied as new and low-cost adsorbent for removal of anionic species from water, there is still a lack of clear characterization for amino groups, especially quaternary ammonium groups in the surface of crop straw. In this study, we used 13C NMR and XPS technologies to characterize adsorbents with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse. 13C NMR spectra clearly showed the presence of quaternary ammonium groups in lignocelluloses structure of modified crop straw. The increase of nitrogen observed in XPS survey spectra also indicated the existence of quaternary ammonium group in the surface of the adsorbents. The curve fitting of high-resolution XPS N1s and C1s spectra were conducted to probe the composition of nitrogen and carbon contained groups, respectively. The results showed the proportion of quaternary ammonium group significantly increased in the prepared adsorbent's surface that was dominated by methyl/methylene, hydroxyl, quaternary ammonium, ether and carbonyl groups. This study proved that 13C NMR and XPS could be successfully utilized for characterization of quaternary ammonium modified crop straw adsorbents.

  13. Foam-based adsorbents having high adsorption capacities for recovering dissolved metals and methods thereof

    Science.gov (United States)

    Janke, Christopher J.; Dai, Sheng; Oyola, Yatsandra

    2015-06-02

    Foam-based adsorbents and a related method of manufacture are provided. The foam-based adsorbents include polymer foam with grafted side chains and an increased surface area per unit weight to increase the adsorption of dissolved metals, for example uranium, from aqueous solutions. A method for forming the foam-based adsorbents includes irradiating polymer foam, grafting with polymerizable reactive monomers, reacting with hydroxylamine, and conditioning with an alkaline solution. Foam-based adsorbents formed according to the present method demonstrated a significantly improved uranium adsorption capacity per unit weight over existing adsorbents.

  14. Metallofullerenes as fuel cell electrocatalysts: a theoretical investigation of adsorbates on C59Pt.

    Science.gov (United States)

    Gabriel, Margaret A; Genovese, Luigi; Krosnicki, Guillaume; Lemaire, Olivier; Deutsch, Thierry; Franco, Alejandro A

    2010-08-28

    Nano-structured electrode degradation in state-of-the-art polymer electrolyte membrane fuel cells (PEMFCs) is one of the main shortcomings that limit the large-scale development and commercialization of this technology. During normal operating conditions of the fuel cell, the PEMFC lifetime tends to be limited by coarsening of the cathode's Pt-based catalyst and by corrosion of the cathode's carbon black support. Because of their chemical properties, metallofullerenes such as C(59)Pt may be more electrochemically stable than the Pt/C mixture. In this paper we investigate, by theoretical methods, the stability of oxygen reduction reaction (ORR) adsorbates on the metallofullerene C(59)Pt and evaluate its potential as a PEMFC fuel cell catalyst.

  15. Modelling the relative stability of carbon nanotubes exposed to environmental adsorbates and air

    International Nuclear Information System (INIS)

    Barnard, Amanda S

    2009-01-01

    In parallel with the development of technological applications for carbon nanotubes, issues related to toxicology and environmental impact are also under increased scrutiny. It is clear from the available literature that the integrity of future carbon nanotube-based devices, our ability to anticipate failure of these devices, and our ability to manage the toxicological and environmental impacts require a detailed understanding of the stability of pure and functionalized carbon nanotubes under a full range of environmental conditions. Motivated by this endeavour, the present study uses a general thermodynamic model to predict the relative stability of carbon nanotubes exposed to a variety of atmospheric adsorbates, and uses them to examine the stability of nanotubes in air, as a function of the relative humidity. In general the results indicate that the adsorption of a sparse coverage of air is thermodynamically favoured, depending on the humidity, and the stability of small diameter nanotubes may be improved by exposure to humid air.

  16. Preparation of iron-modified portland cement adsorbent and the investigation of its decolorization performance

    Science.gov (United States)

    Jiang, Bo; Wang, Huifeng; Li, Yang; Li, Zhen

    2018-02-01

    The ordinary portland cement was modified by ferric salt impregnation method. Through the technologies of x-ray diffraction, scanning electron microscope and energy dispersive spectroscopy, the physicochemical properties of modified cement were detected and analyzed. It was found that after the modification, the main constituents of raw cement, tricalcium silicate and dicalcium silicate had been depleted, and the new crystal mineral of antarcticite replaced them. The iron precipitates and cement hydration products calcium silicate hydrate gel mainly existed in the form of amorphous on modified cement. The results of BET specific surface determination showed that the modified cement particles had mesoporous distribution. The results of adsorption experiment revealed modified cement exhibited excellent adsorption performance on reactive brilliant blue KNR. The combination mechanism between modified cement and adsorbate was mainly electrostatic interaction. The adsorption process satisfied with the pseudo-second order kinetics model, and the adsorption reaction was a spontaneous endothermic process.

  17. Design and performance prediction of a new generation adsorption chiller using composite adsorbent

    International Nuclear Information System (INIS)

    Gong, L.X.; Wang, R.Z.; Xia, Z.Z.; Chen, C.J.

    2011-01-01

    Research highlights: → Composite adsorbent 'employing lithium chloride in silica gel' and water as working pair. → A new type adsorbent bed is used to accommodate the composite adsorbent. → A dynamic model of the adsorption chiller is built. → The coefficient of performance (COP) and the cooling capacity will be improved. -- Abstract: This paper presents a novel adsorption chiller using composite adsorbent 'employing lithium chloride in silica gel' as adsorbent and water as adsorbate. A new type adsorbent bed is used to accommodate the composite adsorbent. The mass recovery between two adsorbent beds usually results in the adsorbate unbalance. So a novel auto water makeup unite is used to solve the problem. A dynamic model of the adsorption chiller is built based on the adsorption isotherms to predict the performance. The simulation result shows that the coefficient of performance (COP) and the cooling capacity will increase by using this new composite adsorbent. When the temperatures of hot water inlet, cooling water inlet, and chilled water inlet are 363, 303 and 293 K, COP will be 0.43, and the cooling capacity will be 5.295 kW. Also operation strategy is optimized. Different temperatures of hot water inlet, cooling water inlet and chilling water inlet will result in different COP and cooling capacity.

  18. Investigation of A-3 adsorbent-ditolylmethane two-phase system

    International Nuclear Information System (INIS)

    Ermakov, V.A.; Benderskaya, O.S.

    1988-01-01

    Compatibility of A-3 adsorbent, produced on the basis of palygoskite clay, with organic coolant of nuclear reactors-ditolylmethane (DTM)- and the possibility to use the given adsorbent for DTM purification from surfactant impurities are investigated. Compatibility of the adsorbent with DTM was evaluated by the concentration of its constituents in liquid phase. Sufactant adsorption was observed by the change in acid number of coolant, optical density at λ=396 nm and adsorbate mass in the adsorbent. From spent adsorbent the coolant was washed out by n-heptane, and the adsorbate - by methylene chloride, othanol and water in succession. On the basis of the results obtained the conclusion is made that A3 possesses a high chemical stability in DTM medium, i.e. it is compatible with DTM and can be used for its purification from surfactant impurities sorbed on heat-transferring surface

  19. Radiation synthesis of stimuli-responsive membranes, hydrogels and adsorbents for separation purposes. Final report of a coordinated research project 2000-2004

    International Nuclear Information System (INIS)

    2005-08-01

    This coordinated research project coordinated research work for the development of novel materials prepared by radiation processing techniques. Single and multi-pore polyamide membranes, fast thermo-responsive hydrogels, porous polymer monoliths, stimuli-responsive hydrogels based on natural and synthetic polymers, temperature responsive membranes, selective adsorbents, polymeric nanogels and novel non-ionic thermo-sensitive hydrogels were produced. The application areas explored for beneficially utilizing these novel materials included specialized drug delivery systems (DDS), selective adsorbents, nanopores for single molecule detection, membranes for separation and concentration of solutes, health care and remediation of environmental pollution. The report provides basic information on radiation processing and promotes experience exchange for further developments of radiation technology. Protocols and procedures of preparation of various stimuli responsive membranes and their actual and perspective applications are described in the report. Public awareness and technology acceptance are other factors to be considered for further dissemination. This publication summarizes the present status and the prospects of this technology

  20. A Preliminary Study for Development of Amidoxime-functionalized Silica Adsorbents for Uranium(IV) Extraction from Seawater

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Minseok; Ryu, Ho Jin [KAIST, Daejeon (Korea, Republic of)

    2016-10-15

    4 billion tons of uranium, which can supply the electricity for tens of thousands of years, is contained in seawater. Therefore, development of techniques for uranium sequestering from the ocean has been regarded as a great challenging for making nuclear energy to be more economical and sustainable. Despite the inexhaustible uranium resource, it is still hard to produce uranium economically from seawater due to its extremely low level of concentration (3.0 μg/L) and stable complex chemical formation, UO{sub 2}(CO3)34-. Various methods for uranium extraction from seawater have been suggested such as precipitation, solvent extraction, ion exchange, adsorption and etc. The most preferred method for extracting uranium is adsorption due to ease of separation from the liquid phase, environment friendliness and cost-effectiveness. Organic or inorganic solids functionalized with amidoxime (AO, -R-C(NH2)=NOH) groups, which has high affinity to uranium species, is the one of candidate material for uranium adsorbents. For long-term nuclear power generation, developing uranium extraction technologies from seawater has been a crucial issue. AO-based adsorbent has been considered as the most effective methods for uranium extraction from seawater, and collaboration with nanotechnology has been tried to enhance the traditional adsorbents, recently. Despite the attempts, most AO-based adsorbents were suffered from complexation of uranyl ions with carbonate ions and under the effect of pH. To achieve more efficient uranium uptake, bi-functionalized mesoporous silica with AO group and acidic groups was chosen as a model for this study.

  1. Nano-Sized Cyclodextrin-Based Molecularly Imprinted Polymer Adsorbents for Perfluorinated Compounds—A Mini-Review

    Directory of Open Access Journals (Sweden)

    Abdalla H. Karoyo

    2015-06-01

    Full Text Available Recent efforts have been directed towards the design of efficient and contaminant selective remediation technology for the removal of perfluorinated compounds (PFCs from soils, sediments, and aquatic environments. While there is a general consensus on adsorption-based processes as the most suitable methodology for the removal of PFCs from aquatic environments, challenges exist regarding the optimal materials design of sorbents for selective uptake of PFCs. This article reviews the sorptive uptake of PFCs using cyclodextrin (CD-based polymer adsorbents with nano- to micron-sized structural attributes. The relationship between synthesis of adsorbent materials and their structure relate to the overall sorption properties. Hence, the adsorptive uptake properties of CD-based molecularly imprinted polymers (CD-MIPs are reviewed and compared with conventional MIPs. Further comparison is made with non-imprinted polymers (NIPs that are based on cross-linking of pre-polymer units such as chitosan with epichlorohydrin in the absence of a molecular template. In general, MIPs offer the advantage of selectivity, chemical tunability, high stability and mechanical strength, ease of regeneration, and overall lower cost compared to NIPs. In particular, CD-MIPs offer the added advantage of possessing multiple binding sites with unique physicochemical properties such as tunable surface properties and morphology that may vary considerably. This mini-review provides a rationale for the design of unique polymer adsorbent materials that employ an intrinsic porogen via incorporation of a macrocyclic compound in the polymer framework to afford adsorbent materials with tunable physicochemical properties and unique nanostructure properties.

  2. Nano-Sized Cyclodextrin-Based Molecularly Imprinted Polymer Adsorbents for Perfluorinated Compounds—A Mini-Review

    Science.gov (United States)

    Karoyo, Abdalla H.; Wilson, Lee D.

    2015-01-01

    Recent efforts have been directed towards the design of efficient and contaminant selective remediation technology for the removal of perfluorinated compounds (PFCs) from soils, sediments, and aquatic environments. While there is a general consensus on adsorption-based processes as the most suitable methodology for the removal of PFCs from aquatic environments, challenges exist regarding the optimal materials design of sorbents for selective uptake of PFCs. This article reviews the sorptive uptake of PFCs using cyclodextrin (CD)-based polymer adsorbents with nano- to micron-sized structural attributes. The relationship between synthesis of adsorbent materials and their structure relate to the overall sorption properties. Hence, the adsorptive uptake properties of CD-based molecularly imprinted polymers (CD-MIPs) are reviewed and compared with conventional MIPs. Further comparison is made with non-imprinted polymers (NIPs) that are based on cross-linking of pre-polymer units such as chitosan with epichlorohydrin in the absence of a molecular template. In general, MIPs offer the advantage of selectivity, chemical tunability, high stability and mechanical strength, ease of regeneration, and overall lower cost compared to NIPs. In particular, CD-MIPs offer the added advantage of possessing multiple binding sites with unique physicochemical properties such as tunable surface properties and morphology that may vary considerably. This mini-review provides a rationale for the design of unique polymer adsorbent materials that employ an intrinsic porogen via incorporation of a macrocyclic compound in the polymer framework to afford adsorbent materials with tunable physicochemical properties and unique nanostructure properties. PMID:28347047

  3. Bioavailability in rats of metal adsorbed to soils

    International Nuclear Information System (INIS)

    Rubenstein, R.; Griffin, S.; Irene, S.; DeRosa, C.; Choudhury, H.

    1990-01-01

    The toxicity of metals to humans and animals has been well documented, however little data are available on the physiological bioavailability of metals from various soil types. These studies were designed to assess the bioavailability of sodium 75 selenate (NaS), 63 nickel chloride (NiCl) and 109 cadmium chloride (CdCl) adsorbed to sand or clay loam in rats. Each test compound was administered in seven dose groups: Group 1 - intravenously, Group 2 and 3 - oral aqueous solution by gavage, Groups 4-7 - aqueous suspension adsorbed to each soil type by gavage. Blood was collected from the jugular vein at intervals up to 48 hours post dosing and analyzed for radio-activity. Both NiCl and CdCl were poorly adsorbed from the soils. Approximately 3% of the CdCl bound to sand and 1.5% of the NiCl bound to clay loam were absorbed into the bloodstream. Approximately 0.5% and 0.1% of the CdCl bound to sand and clay, respectively were absorbed. NaS was well absorbed following oral administration with approximately 85% of the compound bound to sand and 94% bound to clay being absorbed into the blood. Bioavailability of metals from soil appears to be primarily affected by the ionic state of the metal. Anions, such as selenium, are more mobile in an acid environment and may leach more readily from soil. Cations, such as Ni and Cd may bind to soil more tightly, thus soil type becomes a factor affecting bioavailability

  4. Adsorptivity of uranium by aluminium-activated carbon composite adsorbent

    International Nuclear Information System (INIS)

    Katoh, Shunsaku; Sugasaka, Kazuhiko; Fujii, Ayako; Takagi, Norio; Miyai, Yoshitaka

    1976-01-01

    To research the adsorption process of uranium from sea water by aluminium-activated carbon composite adsorbent (C-Al-OH), the authors examined the effects of temperature, pH and carbonate ion concentration of the solution upon the adsorption of uranium, using sodium chloride solution and natural sea water. The continued mixing of the solution for the duration of two to four hours was required to attain the apparent equilibrium of adsorption. The adsorption velocity at an early stage and the uptake of uranium at the final stage showed an increase in proportion to a rise in the adsorption temperature. In the experiment of adsorption for which sodium chloride solution was used, the linear relationship between the logarithm of the distribution coefficient (K sub(d)) and the pH of the solution was recognized. The uptake of the uranium from the solution at the pH of 12 increased as the carbonate ion concentration in the solution decreased. The uranyl ion in the natural sea water was assumed to be uranyl carbonate complex ion (UO 2 (CO 3 ) 3 4- ). As the result of the calculation conducted by using the formation constants for uranyl complexes in literature, it was found that uranyl hydroxo complex ion (UO 2 (OH) 3 - ) increased in line with a decrease of the carbonate ion concentration in the solution. The above results of the experiment suggested that the adsorption of uranium by the adsorbent (C-Al-OH) was cationic adsorption or hydrolysis adsorption being related with the active proton on the surface of the adsorbent. (auth.)

  5. Study of the Adsorbent-Adsorbate Interactions from Cd(II) and Pb(II) Adsorption on Activated Carbon and Activated Carbon Fiber

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Ho; Kim, Doo Won; Kim, Bohye; Yang, Kap Seung [Chonnam National Univ., Gwangju (Korea, Republic of); Lim, Yongkyun; Park, Eun Nam [Microfilter Co., Ltd, Seoul (Korea, Republic of)

    2013-02-15

    The adsorption characteristics of Cd(II) and Pb(II) in aqueous solution using granular activated carbon (GAC), activated carbon fiber (ACF), modified ACF (NaACF), and a mixture of GAC and NaACF (GAC/NaACF) have been studied. The surface properties, such as morphology, surface functional groups, and composition of various adsorbents were determined using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) measurements. The specific surface area, total pore volume, and pore size distribution were investigated using nitrogen adsorption, Brunauer-Emmett-Teller (BET), and Barrett-Joyner-Halenda (BJH) methods. In this study, NaACF showed a high adsorption capacity and rate for heavy metal ions due to the improvement of its ion-exchange capabilities by additional oxygen functional groups. Moreover, the GAC and NaACF mixture was used as an adsorbent to determine the adsorbent-adsorbate interaction in the presence of two competitive adsorbents.

  6. Study of the Adsorbent-Adsorbate Interactions from Cd(II) and Pb(II) Adsorption on Activated Carbon and Activated Carbon Fiber

    International Nuclear Information System (INIS)

    Kim, Dae Ho; Kim, Doo Won; Kim, Bohye; Yang, Kap Seung; Lim, Yongkyun; Park, Eun Nam

    2013-01-01

    The adsorption characteristics of Cd(II) and Pb(II) in aqueous solution using granular activated carbon (GAC), activated carbon fiber (ACF), modified ACF (NaACF), and a mixture of GAC and NaACF (GAC/NaACF) have been studied. The surface properties, such as morphology, surface functional groups, and composition of various adsorbents were determined using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) measurements. The specific surface area, total pore volume, and pore size distribution were investigated using nitrogen adsorption, Brunauer-Emmett-Teller (BET), and Barrett-Joyner-Halenda (BJH) methods. In this study, NaACF showed a high adsorption capacity and rate for heavy metal ions due to the improvement of its ion-exchange capabilities by additional oxygen functional groups. Moreover, the GAC and NaACF mixture was used as an adsorbent to determine the adsorbent-adsorbate interaction in the presence of two competitive adsorbents

  7. Controllable Catalysis with Nanoparticles: Bimetallic Alloy Systems and Surface Adsorbates

    KAUST Repository

    Chen, Tianyou

    2016-05-16

    Transition metal nanoparticles are privileged materials in catalysis due to their high specific surface areas and abundance of active catalytic sites. While many of these catalysts are quite useful, we are only beginning to understand the underlying catalytic mechanisms. Opening the “black box” of nanoparticle catalysis is essential to achieve the ultimate goal of catalysis by design. In this Perspective we highlight recent work addressing the topic of controlled catalysis with bimetallic alloy and “designer” adsorbate-stabilized metal nanoparticles.

  8. Graphene symmetry-breaking with molecular adsorbates: modeling and experiment

    Science.gov (United States)

    Groce, M. A.; Hawkins, M. K.; Wang, Y. L.; Cullen, W. G.; Einstein, T. L.

    2012-02-01

    Graphene's structure and electronic properties provide a framework for understanding molecule-substrate interactions and developing techniques for band gap engineering. Controlled deposition of molecular adsorbates can create superlattices which break the degeneracy of graphene's two-atom unit cell, opening a band gap. We simulate scanning tunneling microscopy and spectroscopy measurements for a variety of organic molecule/graphene systems, including pyridine, trimesic acid, and isonicotinic acid, based on density functional theory calculations using VASP. We also compare our simulations to ultra-high vacuum STM and STS results.

  9. Device for adsorbing exhaled radioactive gases and process

    International Nuclear Information System (INIS)

    Glasser, H.; Panetta, P.F.

    1976-01-01

    Sorption means are provided for sorbing radioactive gases, as in the exhalations of a living subject, especially for nuclear diagnostic test studies, comprising means for adsorbing the radioactive gas onto activated carbon, the carbon being contained in a plurality of independent, series-connected, chambers. The sorption means are especially adapted for the adsorption of radioactive inert gases such as xenon-133 ( 133 Xe). There can also be provided indicator means for indicating the flow-through of xenon comprising an indicator which changes color upon contact with xenon, such as dioxygenylhexafluoroantimoniate. 14 claims, 7 drawing figures

  10. Controllable Catalysis with Nanoparticles: Bimetallic Alloy Systems and Surface Adsorbates

    KAUST Repository

    Chen, Tianyou; Rodionov, Valentin

    2016-01-01

    Transition metal nanoparticles are privileged materials in catalysis due to their high specific surface areas and abundance of active catalytic sites. While many of these catalysts are quite useful, we are only beginning to understand the underlying catalytic mechanisms. Opening the “black box” of nanoparticle catalysis is essential to achieve the ultimate goal of catalysis by design. In this Perspective we highlight recent work addressing the topic of controlled catalysis with bimetallic alloy and “designer” adsorbate-stabilized metal nanoparticles.

  11. 3,5-Dichlorophenol Removal From Wastewater Using Alternative Adsorbents

    Science.gov (United States)

    Kobetičová, Hana; Lipovský, Marek; Wachter, Igor; Soldán, Maroš

    2015-06-01

    The main objective of this paper is to evaluate the efficiency of 3,5-dichlorophenol removal from wastewater by using alternative low cost adsorbents. Waste from the production and processing of metals (black nickel mud, red mud) and a biosorbent (Lemna minor) were used for this research. Initial concentration of the contaminant was 4 mmol L-1, the contact time of sorbent and waste water was 0 - 48 hrs and the temperature during experiment was 25 ± 0.2 °C. The results show that the highest removal efficiency of 3,5 - dichlorophenol (58.18 %) was reached by the red mud in 48 hours.

  12. 3,5-Dichlorophenol Removal From Wastewater Using Alternative Adsorbents

    Directory of Open Access Journals (Sweden)

    Kobetičová Hana

    2015-06-01

    Full Text Available The main objective of this paper is to evaluate the efficiency of 3,5-dichlorophenol removal from wastewater by using alternative low cost adsorbents. Waste from the production and processing of metals (black nickel mud, red mud and a biosorbent (Lemna minor were used for this research. Initial concentration of the contaminant was 4 mmol L−1, the contact time of sorbent and waste water was 0 - 48 hrs and the temperature during experiment was 25 ± 0.2 °C. The results show that the highest removal efficiency of 3,5 - dichlorophenol (58.18 % was reached by the red mud in 48 hours.

  13. Removing 3,5-Dichlorophenol from Wastewater by Alternative Adsorbents

    Directory of Open Access Journals (Sweden)

    Kobetičová Hana

    2014-12-01

    Full Text Available The main objective of this paper is to evaluate an efficiency of 3,5 - dichlorophenol removal from wastewater by using alternative adsorbents. Chlorophenols are organic compounds consisting of a benzene ring, OH groups and also atoms of chlorine. Chlorophenols may have a huge isomere variety that means there are differences in their chemical and physical properties. Due to their toxicity it is necessary to remove them from waste water and in this paper an alternative way of such process is described.

  14. Effects of adsorbates on Zircaloy oxidation in air

    International Nuclear Information System (INIS)

    Cho, Y.; Kim, Y-G.; Park, K.

    1997-01-01

    The air-oxidation of Zry and the effects of adsorbates on the oxidation are found by the intermittent measurement of the weight gain of specimens. NaC1 enhances the oxidation, where nonuniform stresses on the surface and C1 ions are the cause. LiOH also enhances the oxidation, where the initial oxide formed by LiOH seems to the reason. The effects of fluorides on oxidation are also measured. NaF is most harmful and KF follows next. LiF does not effect the oxidation of Zry. Diffusion of fluorides in oxide determines the enhancement. (author)

  15. Inelastic neutron scattering of H2 adsorbed in HKUST-1

    International Nuclear Information System (INIS)

    Liu, Y.; Brown, C.M.; Neumann, D.A.; Peterson, V.K.; Kepert, C.J.

    2007-01-01

    A series of inelastic neutron scattering (INS) investigations of hydrogen adsorbed in activated HKUST-1 (Cu 3 (1,3,5-benzenetricarboxylate) 2 ) result in INS spectra with rich features, even at very low loading ( 2 :Cu). The distinct inelastic features in the spectra show that there are three binding sites that are progressively populated when the H 2 loading is less than 2.0 H 2 :Cu, which is consistent with the result obtained from previous neutron powder diffraction experiments. The temperature dependence of the INS spectra reveals the relative binding enthalpies for H 2 at each site

  16. Behavior of adsorbed Poly-A onto sodium montmorillonite

    Energy Technology Data Exchange (ETDEWEB)

    Palomino-Aquino, Nayeli [Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México (Mexico); Negrón-Mendoza, Alicia, E-mail: negron@nucleares.unam.mx [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México (Mexico)

    2015-07-23

    The adsorption of Poly-A (a polynucleotide consisting of adenine, ribose and a phosphate group), onto a clay mineral, was studied to investigate the extent of adsorption, the site of binding, and the capacity of the clay to protect Poly-A, while it is adsorbed onto the clay, from external sources of energy. The results showed that Poly-A presented a high percentage of adsorption at the edges of the clay and that the survival of the polynucleotide was superior to irradiating the polymer in the absence of the clay.

  17. Influence of * OH adsorbates on the potentiodynamics of the CO 2 generation during the electro-oxidation of ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Guangxing; Namin, Lida M.; Aaron Deskins, N.; Teng, Xiaowei

    2017-09-01

    Direct ethanol fuel cells (DEFCs) are a promising technology for the generation of electricity via the direct conversion of ethanol into CO2, showing higher thermodynamic efficiency and volumetric energy density than hydrogen fuel cells. However, implementation of DEFCs is hampered by the low CO2 selectivity during the ethanol oxidation reaction (EOR). Comprehensive understanding of the electro-kinetics and reaction pathways of CO2 generation via CC bond-breaking is not only a fundamental question for electro-catalysis, but also a key technological challenge since practical implementation of DEFC technology is contingent on its ability to selectively oxidize ethanol into CO2 to achieve exceptional energy density through 12-electron transfer reaction. Here, we present comprehensive in situ potentiodynamics studies of CO2 generation during the EOR on Pt, Pt/SnO2 and Pt/Rh/SnO2 catalysts using a house-made electrochemical cell equipped with a CO2 microelectrode. Highly sensitive CO2 measurements enable the real time detection of the partial pressure of CO2 during linear sweep voltammetry measurements, through which electro-kinetics details of CO2 generation can be obtained. In situ CO2 measurements provide the mechanistic understanding of potentiodynamics of the EOR, particularly the influence of *OH adsorbates on CO2 generation rate and selectivity. Density functional theory (DFT) simulations of Pt, Pt/SnO2, and Pt/Rh/SnO2 surfaces clarify reaction details over these catalysts. Our results show that at low potentials, inadequate *OH adsorbates impair the removal of reaction intermediates, and thus Pt/Rh/SnO2 exhibited the best performance toward CO2 generation, while at high potentials, Rh sites were overwhelmingly occupied (poisoned) by *OH adsorbates, and thus Pt/SnO2 exhibited the best performance toward CO2 generation.

  18. Combination of rice husk and coconut shell activated adsorbent to adsorb Pb(II) ionic metal and it’s analysis using solid-phase spectrophotometry (sps)

    Science.gov (United States)

    Rohmah, D. N.; Saputro, S.; Masykuri, M.; Mahardiani, L.

    2018-03-01

    The purpose of this research was to know the effect and determine the mass comparation which most effective combination between rice husk and coconut shell activated adsorbent to adsorb Pb (II) ion using SPS method. This research used experimental method. Technique to collecting this datas of this research is carried out by several stages, which are: (1) carbonization of rice husk and coconut shell adsorbent using muffle furnace at a temperature of 350°C for an hour; (2) activation of the rice husk and coconut shell adsorbent using NaOH 1N and ZnCl2 15% activator; (3) contacting the adsorbent of rice husk and coconut shell activated adsorbent with liquid waste simulation of Pb(II) using variation comparison of rice husk and coconut shell, 1:0; 0:1; 1:1; 2:1; 1:2; (4) analysis of Pb(II) using Solid-Phase Spectrophotometry (SPS); (5) characterization of combination rice husk and coconut shell activated adsorbent using FTIR. The result of this research show that the combined effect of combination rice husk and coconut shell activated adsorbent can increase the ability of the adsorbent to absorb Pb(II) ion then the optimum adsorbent mass ratio required for absorbing 20 mL of Pb(II) ion with a concentration of 49.99 µg/L is a ratio of 2:1 with the absorption level of 97,06%Solid-Phase Spectrophotometry (SPS) is an effective method in the level of µg/L, be marked with the Limit of Detection (LOD) of 0.03 µg/L.

  19. MgO-based adsorbents for CO2 adsorption: Influence of structural and textural properties on the CO2 adsorption performance.

    Science.gov (United States)

    Elvira, Gutiérrez-Bonilla; Francisco, Granados-Correa; Víctor, Sánchez-Mendieta; Alberto, Morales-Luckie Raúl

    2017-07-01

    A series of MgO-based adsorbents were prepared through solution-combustion synthesis and ball-milling process. The prepared MgO-based powders were characterized using X-ray diffraction, scanning electron microscopy, N 2 physisorption measurements, and employed as potential adsorbents for CO 2 adsorption. The influence of structural and textural properties of these adsorbents over the CO 2 adsorption behaviour was also investigated. The results showed that MgO-based products prepared by solution-combustion and ball-milling processes, were highly porous, fluffy, nanocrystalline structures in nature, which are unique physico-chemical properties that significantly contribute to enhance their CO 2 adsorption. It was found that the MgO synthesized by solution combustion process, using a molar ratio of urea to magnesium nitrate (2:1), and treated by ball-milling during 2.5hr (MgO-BM2.5h), exhibited the maximum CO 2 adsorption capacity of 1.611mmol/g at 25°C and 1atm, mainly via chemisorption. The CO 2 adsorption behaviour on the MgO-based adsorbents was correlated to their improved specific surface area, total pore volume, pore size distribution and crystallinity. The reusability of synthesized MgO-BM2.5h was confirmed by five consecutive CO 2 adsorption-desorption times, without any significant loss of performance, that supports the potential of MgO-based adsorbent. The results confirmed that the special features of MgO prepared by solution-combustion and treated by ball-milling during 2.5hr are favorable to be used as effective MgO-based adsorbent in post-combustion CO 2 capture technologies. Copyright © 2016. Published by Elsevier B.V.

  20. Adsorbed Polymer Nanolayers on Solids: Mechanism, Structure and Applications

    Science.gov (United States)

    Sen, Mani Kuntal

    In this thesis, by combining various advanced x-ray scattering, spectroscopic and other surface sensitive characterization techniques, I report the equilibrium polymer chain conformations, structures, dynamics and properties of polymeric materials at the solid-polymer melt interfaces. Following the introduction, in chapter 2, I highlight that the backbone chains (constituted of CH and CH2 groups) of the flattened polystyrene (PS) chains preferentially orient normal to the weakly interactive substrate surface via thermal annealing regardless of the initial chain conformations, while the orientation of the phenyl rings becomes randomized, thereby increasing the number of surface-segmental contacts (i.e., enthalpic gain) which is the driving force for the flattening process of the polymer chains even onto a weakly interactive solid. In chapter 3, I elucidate the flattened structures in block copolymer (BCP) thin films where both blocks lie flat on the substrate, forming a 2D randomly phase-separated structure irrespective of their microdomain structures and interfacial energetics. In chapter 4, I reveal the presence of an irreversibly adsorbed BCP layer which showed suppressed dynamics even at temperatures far above the individual glass transition temperatures of the blocks. Furthermore, this adsorbed BCP layer plays a crucial role in controlling the microdomain orientation in the entire film. In chapter 5, I report a radically new paradigm of designing a polymeric coating layer of a few nanometers thick ("polymer nanolayer") with anti-biofouling properties.

  1. Adsorbent cartridge for the exhaust of diazo process machines

    International Nuclear Information System (INIS)

    Michlin, N.; Thies, E.J.

    1982-01-01

    A disposable cartridge filled with a chemical composition that acts as an adsorbent for ammonia vapor is adapted to be used in connection with a diazo process printing machine having a vacuum exhausted chamber. Exhaust from the chamber is passed through the cartridge to remove the noxious ammonia vapors and then is vented into the atmosphere. The cartridge is housed in an elongated rectangular cardboard box having three end flaps formed at each of its opposed open ends. Two opposed flaps of each set are formed with central holes and a plastic screen section adhered between these flaps to retain and allow access to the center section of the box which contains the adsorbent chemical. The center end flaps have knock-outs or tear strips that allow holes to be formed in their centers. These center end flaps cover the screens during shipment and when the cartridge is ready for use the center sections of these end flaps are knocked-out to allow the machine exhaust to be vented into and out of the cartridge

  2. Solvent cleanup using base-treated silica gel solid adsorbent

    International Nuclear Information System (INIS)

    Tallent, O.K.; Mailen, J.C.; Pannell, K.D.

    1984-06-01

    A solvent cleanup method using silica gel columns treated with either sodium hydroxide (NaOH) or lithium hydroxide (LiOH) has been investigated. Its effectiveness compares favorably with that of traditional wash methods. After treatment with NaOH solution, the gels adsorb HNO 3 , dibutyl phosphate (DBP), UO 2 2+ , Pu 4+ , various metal-ion fission products, and other species from the solvent. Adsorption mechanisms include neutralization, hydrolysis, polymerization, and precipitation, depending on the species adsorbed. Sodium dibutyl phosphate, which partially distributes to the solvent from the gels, can be stripped with water; the stripping coefficient ranges from 280 to 540. Adsorption rates are diffusion controlled such that temperature effects are relatively small. Recycle of the gels is achieved either by an aqueous elution and recycle sequence or by a thermal treatment method, which may be preferable. Potential advantages of this solvent cleanup method are that (1) some operational problems are avoided and (2) the amount of NaNO 3 waste generated per metric ton of nuclear fuel reprocessed would be reduced significantly. 19 references, 6 figures, 12 tables

  3. Ceramics adsorbing virus and cells. Uirusu, saibo bunri ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Hiraide, T. (Asahi Optical Co. Ltd., Tokyo (Japan))

    1993-07-01

    It has been reported that hydroxyapatite (HA), which is the main inorganic component of teeth and bones of homo sapiens and used for biomaterials such as artificial tooth roots, adsorbs viruses such as influenza viruses. In this article, the history of development up to now of HA and its adsorption mechanism of protein, virus, etc., are introduced. HA was applied for chromatography in 1956 becoming one of the separating and refining methods of protein and nucleic acid, then after the development of spherical porous HA, it has become applied for high speed liquid chromatography (HPLC). Also by means of a column filled with HA granules, T-cells have been able to be purified in a short time from lymphocyte which was separated from the blood of homo sapiens. Recently it has also been reported that HA granules can adsorb influenza viruses, Japanese encephalitis viruses, polio viruses and hepatitis B viruses, and a cold-preventative mask based upon this report is now on sale. 11 refs., 7 figs.

  4. Sustainable conversion of agro-wastes into useful adsorbents

    Science.gov (United States)

    Bello, Olugbenga Solomon; Owojuyigbe, Emmanuel Seun; Babatunde, Monsurat Abiodun; Folaranmi, Folasayo Eunice

    2017-11-01

    Preparation and characterization of raw and activated carbon derived from three different selected agricultural wastes: kola nut pod raw and activated (KNPR and KNPA), bean husk raw and activated (BHR and BHA) and coconut husk raw and activated (CHR and CHA) were investigated, respectively. Influences of carbonization and acid activation on the activated carbon were investigated using SEM, FTIR, EDX, pHpzc and Boehm titration techniques, respectively. Carbonization was done at 350 °C for 2 h followed by activation with 0.3 M H3PO4 (ortho-phosphoric acid). Results obtained from SEM, FTIR, and EDX revealed that, carbonization followed by acid activation had a significant influence on morphology and elemental composition of the samples. SEM showed well-developed pores on the surface of the precursors after acid treatment, FTIR spectra revealed reduction, broadening, disappearance or appearance of new peaks after acid activation. EDX results showed highest percentage of carbon by atom respectively in the order BHA > KNPA > CHA respectively. The pHpzc was found to be 5.32, 4.57 and 3.69 for KNPA, BHA and CHA, respectively. Boehm titration result compliments that of pHpzc, indicating that the surfaces of the prepared adsorbents are predominantly acidic. This study promotes a sustainable innovative use of agro-wastes in the production of cheap and readily available activated carbons, thereby ensuring more affordable water and effluent treatment adsorbents.

  5. Waste metal hydroxide sludge as adsorbent for a reactive dye.

    Science.gov (United States)

    Santos, Sílvia C R; Vílar, Vítor J P; Boaventura, Rui A R

    2008-05-30

    An industrial waste sludge mainly composed by metal hydroxides was used as a low-cost adsorbent for removing a reactive textile dye (Remazol Brilliant Blue) in solution. Characterization of this waste material included chemical composition, pH(ZPC) determination, particle size distribution, physical textural properties and metals mobility under different pH conditions. Dye adsorption equilibrium isotherms were determined at 25 and 35 degrees C and pH of 4, 7 and 10 revealing reasonably fits to Langmuir and Freundlich models. At 25 degrees C and pH 7, Langmuir fit indicates a maximum adsorption capacity of 91.0mg/g. An adsorptive ion-exchange mechanism was identified from desorption studies. Batch kinetic experiments were also conducted at different initial dye concentration, temperature, adsorbent dosage and pH. A pseudo-second-order model showed good agreement with experimental data. LDF approximation model was used to estimate homogeneous solid diffusion coefficients and the effective pore diffusivities. Additionally, a simulated real effluent containing the selected dye, salts and dyeing auxiliary chemicals, was also used in equilibrium and kinetic experiments and the adsorption performance was compared with aqueous dye solutions.

  6. Pulling adsorbed polymers at an angle: A low temperature theory

    Science.gov (United States)

    Iliev, Gerasim; Whittington, Stuart

    2012-02-01

    We consider several partially-directed walk models in two- and three-dimensions to study the problem of a homopolymer interacting with a surface while subject to a force at the terminal monomer. The force is applied with a component parallel to the surface as well as a component perpendicular to the surface. Depending on the relative values of the force in each direction, the force can either enhance the adsorption transition or lead to desorption in an adsorbed polymer. For each model, we determine the associated generating function and extract the phase diagram, identifying states where the polymer is thermally desorbed, adsorbed, and under the influence of the force. We note the different regimes that appear in the problem and provide a low temperature approximation to describe them. The approximation is exact at T=0 and models the exact results extremely well for small values of T. This work is an extension of a model considered by S. Whittington and E. Orlandini.

  7. Optical emissions from oxygen atom reactions with adsorbates

    Science.gov (United States)

    Oakes, David B.; Fraser, Mark E.; Gauthier-Beals, Mitzi; Holtzclaw, Karl W.; Malonson, Mark; Gelb, Alan H.

    1992-12-01

    Although most optical materials are inert to the ambient low earth orbit environment, high velocity oxygen atoms will react with adsorbates to produce optical emissions from the ultraviolet into the infrared. The adsorbates arise from chemical releases or outgassing from the spacecraft itself. We have been investigating kinetic and spectral aspects of these phenomenon by direct observation of the 0.2 to 13 micrometers chemiluminescence from the interaction of a fast atomic oxygen beam with a continuously dosed surface. The dosing gases include fuels, combustion products and outgassed species such as unsymmetrical dimethylhydrazine (UDMH), NO, H2O and CO. The surface studied include gold and magnesium fluoride. In order to relate the results to actual spacecraft conditions these phenomena have been explored as a function of O atom velocity, dosant flux and substrate temperature. UDMH dosed surfaces exhibit spectra typical (wavelength and intensity) of carbonaceous surfaces. The primary emitters are CO, CO2, and OH. H2O dosed surfaces are dominated by OH and /or H2O emission while CO dosed surfaces are dominated by CO and CO2 emissions. The nitric oxide dosed surface produces a glow from 0.4 to 5.4 micrometers due to NO2* continuum emission. The emission was observed to increase by a factor of two upon cooling the surface from 20 degree(s)C to -35 degree(s)C.

  8. The development of advanced gas cooled reactor iodine adsorber systems

    International Nuclear Information System (INIS)

    Meddings, P.

    1986-01-01

    Advanced Gas Cooled Reactors (AGRs) are provided with plants to process the carbon dioxide coolant prior to its discharge to atmosphere. Included in these are beds of granular activated charcoal, contained within a suitable pressure vessel, through which the high pressure carbon dioxide is passed for the purpose of retaining iodine and iodine-containing compounds. Carry-over carbon dust from the adsorption beds was identified during active in-situ commissioning testing, radio-iodine being transported with the particulate material due to gross disturbance of the adsorber carbon bed and displacement of the vessel internals. The methods used to identify the causes of the problems and find solutions are described. A development programme for the Heysham-2 and Torness reactors iodine adsorber units was set up to identify a method of de-dusting granular charcoal and develop it for full-scale use, of assess the effect under conditions of high gas density of approach velocity on charcoal fines production and to establish the pressure drop characteristics of a packed granular bed and to develop an effective design of inlet gas diffuser manifold to ensure an acceptable velocity distribution. This has involved the construction of a small scale high pressure carbon dioxide rig and development of an air flow model. This work is described. (UK)

  9. Radiolytic stability of gibbsite and boehmite with adsorbed water

    Energy Technology Data Exchange (ETDEWEB)

    Huestis, Patricia; Pearce, Carolyn I.; Zhang, X.; N' Diaye, Alpha T.; Rosso, Kevin M.; LaVerne, Jay A.

    2018-04-01

    Aluminum oxyhydroxide (boehmite, AlOOH) and aluminum hydroxide (gibbsite, Al(OH)3) powders with adsorbed water were irradiated with -rays and 5 MeV He ions (α-particles) in order to determine overall radiation stability and chemical modification to the surface. No variation in overall phase or crystallinity due to radiolysis was observed with X-ray diffraction (XRD) and Raman spectroscopy for doses up to 2 MGy with -rays and 175 MGy with α-particles. Temperature programed desorption (TPD) of the water from the surface to the gas phase indicated that the water was chemisorbed and strongly bound. Water adsorption sites are of similar energy for both gibbsite and boehmite. Observation of the water adsorbed on the surface of gibbsite and boehmite with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) showed broad peaks at 3100-3600 cm-1 due to OH stretching that slowly decreased on heating to 500oC, which corresponds well with the water vapor evolution observed with TPD. Both materials were found to be amorphous following heating to 500oC. X-ray photoelectron spectroscopy (XPS) indicated surface reduction of Al(III) to Al metal on radiolysis with α-particles. Complete loss of chemisorbed water and the formation of bulk O atoms was observed following radiolysis with α-particles.

  10. INTERACTION OF CARBON DIOXIDE WITH CARBON ADSORBENTS BELOW 400 C

    Energy Technology Data Exchange (ETDEWEB)

    Deitz, V R; Carpenter, F G; Arnold, R G

    1963-06-15

    The adsorption of carbon dioxide on carbon adsorbents (FT carbon, coconut charcoal, acid-washed bone char) and adsorbents containing basic calcium phosphate (hydroxylapatite, bone char, ash of bone char) was studied. Special consideration was given to the pretreatment of the materials. The carbons equilibrated as rapidly as the temperature; the basic calcium phosphates showed a rapid initial adsorption followed by a very slow rate which continued for days. Linear adsorption isotherms were found on FT carbon and the isosteric heats varied slightiy with coverage. The isotherms for the remaining materials had varying curvature and were for the most part in the same sequence as the estimated surface areas. The isosteric heats of carbon dioxide correlated very well with the magnitude of surface hydroxyl groups, an estimate of which was made from the chemical composition. There appeared to be three increasing levels of interaction: (1) pure physical adsorption; (2) an adsorption complex having 'bicarbonate structure'; and (3) an adsorption complex having 'carbonate structure'. (auth)

  11. Adsorbed Organic Material and Its Control on Wettability

    DEFF Research Database (Denmark)

    Matthiesen, Jesper; Hassenkam, Tue; Bovet, Nicolas Emile

    2017-01-01

    salinity. Here we quantified the response of sandstone core plug material in its preserved state (i.e., after storage in kerosene) and after the same core plug material was treated with ethanol and ozone to remove adsorbed organic compounds. We used the chemical force microscopy (CFM) mode of atomic force...... surfaces in artificial seawater (ASW; 35,600 ppm) and in ASW diluted to ∼1,500 ppm (ASW-low). Both before and after the ethanol/ozone treatment, and for both the alkane and the carboxylate functionalized tips, the adhesion was lower in ASW diluted to ∼1,500 ppm than in ASW. For both alkane and carboxylate...... ethanol/ozone treatment, to be a result of the loss of the organic material that was originally adsorbed on these surfaces, which adds to the charge density and thereby to the salinity dependent EDL force. Investigating the same area on the same pore surface, before and after removal of the organic...

  12. Treatment of uranium mining and milling wastewater using biological adsorbents

    International Nuclear Information System (INIS)

    Tsezos, M.

    1983-01-01

    Selected samples of waste microbial biomass originating from various industrial fermentation processes and biological treatment plants have been screened for biosorbent properties in conjunction with uranium, thorium and radium in aqueous solutions. Biosorption isotherms were used for the evaluation of biosorptive uptake capacity of the biomass. The biomass was also compared to synthetic adsorbents such as activated carbon. Determined uranium, thorium and radium biosorption isotherms were independent of the initial solution concentrations. Solution pH affected uptake. Rhizopus arrhizus at pH 4 exhibited the highest uranium and thorium biosorptive uptake capacity in excess of 180 Mg/g. It removed about 2.5 and 3.3 times more uranium than the ion exchange resin and activated carbon tested. Penicillium chrysogenum adsorbed 50000 pCi/g radium at pH 7 and at an equilibrium radium concentration of 1000 pCi/L. The most effective biomass types studied exhibited removals in excess of 99% of the radium in solution

  13. Microstructured optical fiber-based luminescent biosensing: Is there any light at the end of the tunnel? - A review.

    Science.gov (United States)

    Pidenko, Sergey A; Burmistrova, Natalia A; Shuvalov, Andrey A; Chibrova, Anastasiya A; Skibina, Yulia S; Goryacheva, Irina Y

    2018-08-17

    This review covers the current state of the art of luminescent biosensors based on various types of microstructured optical fiber. The unique optical and structural properties of this type of optical fiber make them one of the most promising integrated platforms for bioassays. The individual sections of this review are devoted to a) classification of microstructured optical fibers, b) microstructured optical fiber materials, c) aspects of biosensing based on the biomolecules incorporated into the microstructured optical fibers, and d) development of models for prediction of the efficiency of luminescent signal processing. The authors' views on current trends and limitations of microstructured optical fibers for biosensing as well as the most promising areas and technologies for application in analytical practice are presented. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Low grade heat driven adsorption system for cooling and power generation using advanced adsorbent materials

    International Nuclear Information System (INIS)

    Al-Mousawi, Fadhel Noraldeen; Al-Dadah, Raya; Mahmoud, Saad

    2016-01-01

    Highlights: • Adsorption system based on water and advanced physical adsorbents has the potential of producing cooling and power. • Adding an expander to physisorption system enhances efficiency by up to 11%. • MIL101Cr MOF can produce 95 W/kg and 1357 W/kg of specific power and cooling. • AQSOA Z02 can produce 73 W/kg and 640 W/kg of specific power and cooling. - Abstract: Globally there is abundance of low grade heat sources (around 150 °C) from renewables like solar energy or from industrial waste heat. The exploitation of such low grade heat sources will reduce fossil fuel consumption and CO_2 emissions. Adsorption technology offers the potential of using such low grade heat to generate cooling and power. In this work, the effect of using advanced adsorbent materials like AQSOA-Z02 (SAPO-34) zeolite and MIL101Cr Metal Organic Framework (MOF) at various operating conditions on power and cooling performance compared to that of commonly used silica-gel was investigated using water as refrigerant. A mathematical model for a two bed adsorption cooling cycle has been developed with the cycle modified to produce power by incorporating an expander between the desorber and the condenser. Results show that it is possible to produce power and cooling at the same time without affecting the cooling output. Results also show that for all adsorbents used as the heat source temperature increases, the cooling effect and power generated increase. As for increasing the cold bed temperature, this will decrease the cooling effect and power output except for SAPO-34 which shows slightly increasing trend of cooling and power output. As the condenser cooling temperature increases, the cooling effect and power output will decrease while for the chilled water temperature, the cooling load and power generated increased as the temperature increased. The maximum values of average specific power generation (SP), specific cooling power (SCP) and cycle efficiency are 73 W

  15. Studies of adsorber materials for preparing 68Ge/68Ga generators

    International Nuclear Information System (INIS)

    Brambilla, Tania de Paula

    2013-01-01

    The 68 Ga is a promising radionuclide for nuclear medicine, decaying by positron emission with an abundance of 89%, with physical half-life of 68 minutes, which is compatible with the pharmacokinetics of many biomolecules and low molecular weight substrates. Another important feature is its availability through a generator system, where the parent radionuclide, 68 Ge (t 1/2 = 270.95 days) is adsorbed on a column and the daughter, 68 Ga, is eluted in an ionic form 68Ga 3+ . The development of 68 Ge/ 68 Ga generators began in the 60s, but its clinical use began to be acceptable and relevant only recently. The method of separation of 68 Ge and 68 Ga most used is the ion-exchange chromatographic system, due to its practical operation, but other generator systems have been proposed, such as solvent extraction and evaporation technique. Currently, 68 Ge/ 68 Ga generators are commercially available using inorganic matrices columns prepared with TiO 2 or SnO 2 as well using organic resin. The efficiency of 68 Ga elution ranges from 70% to 80%, decreasing over time. The 68 Ge breakthrough varies from 10 -2 to10 -3 % or lower in a fresh generator, but there is an increase in the levels of contamination after long periods of use. Even with all the technological advances in the development of 68 Ge/ 68 Ga generators in the past decades, the 68 Ga eluted from commercial generators is not suitable for direct use in humans and some improvements in the systems need to be made to reduce the 68 Ge breakthrough and chemical impurities levels. The main objective of this work was to develop a 68 Ge/ 68 Ga generator system is which 68 Ga could be eluted with quality required for clinical use. The chemical behavior of Ge and Ga was evaluated on various inorganic adsorbents materials. Two types of 68 Ge/ 68 Ga generator systems were developed using TiO 2 as adsorbent material: elution system with manual pressure and vacuum controlled. The efficiencies of the generators were similar to

  16. Oil palm biomass-based adsorbents for the removal of water pollutants--a review.

    Science.gov (United States)

    Ahmad, Tanweer; Rafatullah, Mohd; Ghazali, Arniza; Sulaiman, Othman; Hashim, Rokiah

    2011-07-01

    This article presents a review on the role of oil palm biomass (trunks, fronds, leaves, empty fruit bunches, shells, etc.) as adsorbents in the removal of water pollutants such as acid and basic dyes, heavy metals, phenolic compounds, various gaseous pollutants, and so on. Numerous studies on adsorption properties of various low-cost adsorbents, such as agricultural wastes and its based activated carbons, have been reported in recent years. Studies have shown that oil palm-based adsorbent, among the low-cost adsorbents mentioned, is the most promising adsorbent for removing water pollutants. Further, these bioadsorbents can be chemically modified for better efficiency and can undergo multiple reuses to enhance their applicability at an industrial scale. It is evident from a literature survey of more than 100 recent papers that low-cost adsorbents have demonstrated outstanding removal capabilities for various pollutants. The conclusion is been drawn from the reviewed literature, and suggestions for future research are proposed.

  17. Development of Silver-exchanged Adsorbents for the Removal of Fission Iodine from Alkaline Dissolution

    International Nuclear Information System (INIS)

    Kim, Taewoon; Lee, Seung-Kon; Lee, Suseung; Lee, Jun Sig

    2015-01-01

    Most of the iodine exists in the caustic dissolution as iodide form. KAERI is developing LEU-based fission 99 Mo production process which is connected to the new research reactor, which is being constructed in Kijang, Busan, Korea. In KAERI process, silver-exchanged adsorbent is used to adsorb iodide from the solution. Adsorbed iodide can be recovered and recycled for radiopharmaceuticals. In KAERI process, silver-exchanged adsorbent is used to adsorb iodide from the solution. Adsorbed iodide can be recovered and recycled for radiopharmaceuticals. Synthesis of silver-doped alumina is conducted in two ways. One is using the ascorbic acid as a reducing agent. However, this method is impossible to control

  18. Development of a membrane adsorber based capture step for the purification of yellow fever virus.

    Science.gov (United States)

    Pato, Tânia P; Souza, Marta Cristina O; Silva, Andréa N M R; Pereira, Renata C; Silva, Marlon V; Caride, Elena; Gaspar, Luciane P; Freire, Marcos S; Castilho, Leda R

    2014-05-19

    Yellow fever (YF) is an endemic disease in some tropical areas of South America and Africa that presents lethality rate between 20 and 50%. There is no specific treatment and to control this disease a highly effective live-attenuated egg based vaccine is widely used for travelers and residents of areas where YF is endemic. However, recent reports of rare, sometimes fatal, adverse events post-vaccination have raised concerns. In order to increase safety records, alternative strategies should be considered, such as developing a new inactivated vaccine using a cell culture based technology, capable of meeting the demands in cases of epidemic. With this goal, the production of YF virus in Vero cells grown on microcarriers and its subsequent purification by chromatographic techniques was studied. In this work we investigate the capture step of the purification process of the YF virus. At first, virus stability was studied over a wide pH range, showing best results for the alkaline region. Considering this result and the pI of the envelope protein previously determined in silico, a strong anion exchanger was considered most suitable. Due to the easy scalability, simplicity to handle, absence of diffusional limitations and suitability for virus handling of membrane adsorbers, a Q membrane was evaluated. The amount of antigen adsorbed onto the membrane was investigated within the pH range for virus stability, and the best pH for virus adsorption was considered to be 8.5. Finally, studies on gradient and step elution allowed to determine the most adequate salt concentration for washing (0.15M) and virus elution (0.30 M). Under these operating conditions, it was shown that this capture step is quite efficient, showing high product recovery (93.2±30.3%) and efficient DNA clearance (0.9±0.3 ng/dose). Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Development of a cost-effective CO2 adsorbent from petroleum coke via KOH activation

    Science.gov (United States)

    Jang, Eunji; Choi, Seung Wan; Hong, Seok-Min; Shin, Sangcheol; Lee, Ki Bong

    2018-01-01

    The capture of CO2 via adsorption is considered an effective technology for decreasing global warming issues; hence, adsorbents for CO2 capture have been actively developed. Taking into account cost-effectiveness and environmental concerns, the development of CO2 adsorbents from waste materials is attracting considerable attention. In this study, petroleum coke (PC), which is the carbon residue remaining after heavy oil upgrading, was used to produce high-value-added porous carbon for CO2 capture. Porous carbon materials were prepared by KOH activation using different weight ratios of KOH/PC (1:1, 2:1, 3:1, and 4:1) and activation temperatures (600, 700, and 800 °C). The specific surface area and total pore volume of resulting porous carbon materials increased with KOH amount, reaching up to 2433 m2/g and 1.11 cm3/g, respectively. The sample prepared under moderate conditions with a KOH/PC weight ratio of 2:1 and activation temperature of 700 °C exhibited the highest CO2 adsorption uptake of 3.68 mmol/g at 25 °C and 1 bar. Interestingly, CO2 adsorption uptake was linearly correlated with the volume of micropores less than 0.8 nm, indicating that narrow micropore volume is crucial for CO2 adsorption. The prepared porous carbon materials also exhibited good selectivity for CO2 over N2, rapid adsorption, facile regeneration, and stable adsorption-desorption cyclic performance, demonstrating potential as a candidate for CO2 capture.

  20. Sol-Gel Derived Adsorbents with Enzymatic and Complexonate Functions for Complex Water Remediation

    Directory of Open Access Journals (Sweden)

    Roman P. Pogorilyi

    2017-09-01

    Full Text Available Sol-gel technology is a versatile tool for preparation of complex silica-based materials with targeting functions for use as adsorbents in water purification. Most efficient removal of organic pollutants is achieved by using enzymatic reagents grafted on nano-carriers. However, enzymes are easily deactivated in the presence of heavy metal cations. In this work, we avoided inactivation of immobilized urease by Cu (II and Cd (II ions using magnetic nanoparticles provided with additional complexonate (diethylene triamine pentaacetic acid or DTPA functions. Obtained nanomaterials were characterized by Fourier transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA, and scanning electron microscopy (SEM. According to TGA, the obtained Fe3O4/SiO2-NH2-DTPA nanoadsorbents contained up to 0.401 mmol/g of DTPA groups. In the concentration range Ceq = 0–50 mmol/L, maximum adsorption capacities towards Cu (II and Cd (II ions were 1.1 mmol/g and 1.7 mmol/g, respectively. Langmuir adsorption model fits experimental data in concentration range Ceq = 0–10 mmol/L. The adsorption mechanisms have been evaluated for both of cations. Crosslinking of 5 wt % of immobilized urease with glutaraldehyde prevented the loss of the enzyme in repeated use of the adsorbent and improved the stability of the enzymatic function leading to unchanged activity in at least 18 cycles. Crosslinking of 10 wt % urease on the surface of the particles allowed a decrease in urea concentration in 20 mmol/L model solutions to 2 mmol/L in up to 10 consequent decomposition cycles. Due to the presence of DTPA groups, Cu2+ ions in concentration 1 µmol/L did not significantly affect the urease activity. Obtained magnetic Fe3O4/SiO2-NH2-DTPA-Urease nanocomposite sorbents revealed a high potential for urease decomposition, even in presence of heavy metal ions.

  1. Surface atomic relaxation and magnetism on hydrogen-adsorbed Fe(110) surfaces from first principles

    Energy Technology Data Exchange (ETDEWEB)

    Chohan, Urslaan K.; Jimenez-Melero, Enrique [School of Materials, The University of Manchester, Manchester M13 9PL (United Kingdom); Dalton Cumbrian Facility, The University of Manchester, Moor Row CA24 3HA (United Kingdom); Koehler, Sven P.K., E-mail: sven.koehler@manchester.ac.uk [Dalton Cumbrian Facility, The University of Manchester, Moor Row CA24 3HA (United Kingdom); School of Chemistry, The University of Manchester, Manchester M13 9PL (United Kingdom); Photon Science Institute, The University of Manchester, Manchester M13 9PL (United Kingdom)

    2016-11-30

    Highlights: • Potential energy surfaces for H diffusion on Fe(110) calculated. • Full vibrational analysis of surface modes performed. • Vibrational analysis establishes lb site as a transition state to the 3f site. • Pronounced buckling observed in the Fe surface layer. - Abstract: We have computed adsorption energies, vibrational frequencies, surface relaxation and buckling for hydrogen adsorbed on a body-centred-cubic Fe(110) surface as a function of the degree of H coverage. This adsorption system is important in a variety of technological processes such as the hydrogen embrittlement in ferritic steels, which motivated this work, and the Haber–Bosch process. We employed spin-polarised density functional theory to optimise geometries of a six-layer Fe slab, followed by frozen mode finite displacement phonon calculations to compute Fe–H vibrational frequencies. We have found that the quasi-threefold (3f) site is the most stable adsorption site, with adsorption energies of ∼3.0 eV/H for all coverages studied. The long-bridge (lb) site, which is close in energy to the 3f site, is actually a transition state leading to the stable 3f site. The calculated harmonic vibrational frequencies collectively span from 730 to 1220 cm{sup −1}, for a range of coverages. The increased first-to-second layer spacing in the presence of adsorbed hydrogen, and the pronounced buckling observed in the Fe surface layer, may facilitate the diffusion of hydrogen atoms into the bulk, and therefore impact the early stages of hydrogen embrittlement in steels.

  2. Cell fiber-based three-dimensional culture system for highly efficient expansion of human induced pluripotent stem cells.

    Science.gov (United States)

    Ikeda, Kazuhiro; Nagata, Shogo; Okitsu, Teru; Takeuchi, Shoji

    2017-06-06

    Human pluripotent stem cells are a potentially powerful cellular resource for application in regenerative medicine. Because such applications require large numbers of human pluripotent stem cell-derived cells, a scalable culture system of human pluripotent stem cell needs to be developed. Several suspension culture systems for human pluripotent stem cell expansion exist; however, it is difficult to control the thickness of cell aggregations in these systems, leading to increased cell death likely caused by limited diffusion of gases and nutrients into the aggregations. Here, we describe a scalable culture system using the cell fiber technology for the expansion of human induced pluripotent stem (iPS) cells. The cells were encapsulated and cultured within the core region of core-shell hydrogel microfibers, resulting in the formation of rod-shaped or fiber-shaped cell aggregations with sustained thickness and high viability. By encapsulating the cells with type I collagen, we demonstrated a long-term culture of the cells by serial passaging at a high expansion rate (14-fold in four days) while retaining its pluripotency. Therefore, our culture system could be used for large-scale expansion of human pluripotent stem cells for use in regenerative medicine.

  3. Oil adsorbing package, also procedure to remove oil from a water surface

    Energy Technology Data Exchange (ETDEWEB)

    1971-05-01

    A method is given to remove oil from water to prevent water pollution. Use is made of an oil-adsorbing packet having a specific gravity which is lower than the specific gravity of water. The hull is manufactured from any material which is not a water-insoluble nonpolar material. The hull is partly permeable to water and encloses a solid oil-adsorbing compound having a large adsorbing surface. (10 claims)

  4. Screening of natural adsorbents for removal of radio-contaminants from aqueous effluents

    International Nuclear Information System (INIS)

    Thorat, Vidya; Katarni, V.G.; Kaushik, C.P.; Kaushik, Chander P.; Sharma, J.K.

    2010-01-01

    The present paper is a summary of studies carried out to examine the uptake potential of some of the bio/natural adsorbents for removal of radiocontaminants from aqueous effluents. Three different bio/natural materials namely coconut coir pith, sugarcane bagasse and saw dust were selected as adsorbents. Preliminary characterisations of the above adsorbents were carried out and percentage of removal of 239 Pu and 241 Am from aqueous solutions were checked using batch equilibration method. (author)

  5. Toward an effective adsorbent for polar pollutants: Formaldehyde adsorption by activated carbon

    International Nuclear Information System (INIS)

    Lee, Kyung Jin; Miyawaki, Jin; Shiratori, Nanako; Yoon, Seong-Ho; Jang, Jyongsik

    2013-01-01

    Highlights: • Activated carbon fiber with mild activation condition is useful as adsorbent for polar pollutants. • Diverse variations are investigated for developing an effective adsorbent. • Surface functional group is the most important factor for capacity as a adsorbent. • Surface functional groups on ACFs are investigated using micro-ATR FTIR. -- Abstract: Due to increasing concerns about environmental pollutants, the development of an effective adsorbent or sensitive sensor has been pursued in recent years. Diverse porous materials have been selected as promising candidates for detecting and removing harmful materials, but the most appropriate pore structure and surface functional groups, both important factors for effective adsorbency, have not yet been fully elucidated. In particular, there is limited information relating to the use of activated carbon materials for effective adsorbent of specific pollutants. Here, the pore structure and surface functionality of polyacrylonitrile-based activated carbon fibers were investigated to develop an efficient adsorbent for polar pollutants. The effect of pore structure and surface functional groups on removal capability was investigated. The activated carbons with higher nitrogen content show a great ability to absorb formaldehyde because of their increased affinity with polar pollutants. In particular, nitrogen functional groups that neighbor oxygen atoms play an important role in maximizing adsorption capability. However, because there is also a similar increase in water affinity in adsorbents with polar functional groups, there is a considerable decrease in adsorption ability under humid conditions because of preferential adsorption of water to adsorbents. Therefore, it can be concluded that pore structures, surface functional groups and the water affinity of any adsorbent should be considered together to develop an effective and practical adsorbent for polar pollutants. These studies can provide vital

  6. On the influence of adsorber performance on plant design for the extraction of uranium from seawater

    International Nuclear Information System (INIS)

    Koske, P.H.; Ohlrogge, K.

    1983-01-01

    Based on simple seawater and dissolved uranium balances the influence of specific adsorber parameters on size and design of production plants with fluidized adsorber beds for the extraction of uranium from seawater is discussed. Besides a critical review of two recently published plant designs in the USA and Japan experimentally determined adsorber data for a polyamidoxim (PAO) granulate are presented together with an evaluation of their influence on the key plant parameters. (orig.) [de

  7. Selective cesium removal from radioactive liquid waste by crown ether immobilized new class conjugate adsorbent

    OpenAIRE

    Awual, M. R.; 矢板 毅; 田口 富嗣; 塩飽 秀啓; 鈴木 伸一; 岡本 芳浩

    2014-01-01

    Conjugate materials can provide chemical functionality, enabling an assembly of the ligand complexation ability to metal ions that are important for applications, such as separation and removal devices. In this study, we developed ligand immobilized conjugate adsorbent for selective cesium (Cs) removal from wastewater. The adsorbent was synthesized by direct immobilization of DB24C8 onto inorganic mesoporous silica. The obtained results revealed that adsorbent had higher selectivity towards C...

  8. Synthesis of adsorbent from Tamarix hispida and modified by lanthanum metal for fluoride ions removal from wastewater: Adsorbent characteristics and real wastewater treatment data

    Directory of Open Access Journals (Sweden)

    Nasim Habibi

    2017-08-01

    Full Text Available This data article describes a facile method for production of an adsorbent from Tamarix hispida wasted wood and modified by lanthanum metal for fluoride ions removal from wastewater. The main characteristics of the adsorbent consist of BET surface area, functional groups, and elemental analysis is presented. The data for attenuating the pollutants from a real wastewater treatment which was provided from a glass factory is also represented. More than 90% of fluoride content of the real wastewater was treated by the adsorbent. Generally, these data would be informative for extend research aim to industrial wastewater treatment and those who work in the wastewater treatment plants.

  9. Chemical and structural characterization of copper adsorbed on mosses (Bryophyta)

    Energy Technology Data Exchange (ETDEWEB)

    González, Aridane G., E-mail: aridaneglez@gmail.com [GET (Géosciences Environnement Toulouse) UMR 5563CNRS, 14 Avenue Edouard Belin, F-31400 Toulouse (France); Jimenez-Villacorta, Felix [Instituto de Ciencia de Materiales Madrid, CSIC, Cantoblanco, E-28049 Madrid (Spain); Beike, Anna K. [Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestrasse 1, 79104 Freiburg (Germany); State Museum of Natural History Stuttgart, Rosenstein 1, 70191 Stuttgart (Germany); Reski, Ralf [Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestrasse 1, 79104 Freiburg (Germany); BIOSS—Centre for Biological Signalling Studies, 79104 Freiburg (Germany); FRIAS—Freiburg Institute for Advanced Studies, 79104 Freiburg (Germany); Adamo, Paola [Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Naples (Italy); Pokrovsky, Oleg S. [GET (Géosciences Environnement Toulouse) UMR 5563CNRS, 14 Avenue Edouard Belin, F-31400 Toulouse (France); BIO-GEO-CLIM Laboratory, Tomsk State University, Tomsk (Russian Federation); Institute of Ecological Problems of the North, Russian Academy of Science, Arkhangelsk (Russian Federation)

    2016-05-05

    Highlights: • Cu{sup 2+} was adsorbed on four mosses used in moss-bag pollution monitoring technique. • Thermodynamic approach was used to model Cu speciation based on XAS results. • All studied mosses have ∼4.5 O/N atoms at ∼1.95 Å around Cu likely in a pseudo-square geometry. • Cu(II)-carboxylates and Cu(II)-phosphoryls are the main moss surface binding groups. • Moss growing in batch reactor yielded ∼20% of Cu(I) in the form of Cu–S(CN) complexes. - Abstract: The adsorption of copper on passive biomonitors (devitalized mosses Hypnum sp., Sphagnum denticulatum, Pseudoscleropodium purum and Brachythecium rutabulum) was studied under different experimental conditions such as a function of pH and Cu concentration in solution. Cu assimilation by living Physcomitrella patents was also investigated. Molecular structure of surface adsorbed and incorporated Cu was studied by X-ray Absorption Spectroscopy (XAS). Devitalized mosses exhibited the universal adsorption pattern of Cu as a function of pH, with a total binding sites number 0.05–0.06 mmolg{sub dry}{sup −1} and a maximal adsorption capacity of 0.93–1.25 mmolg{sub dry}{sup −1} for these devitalized species. The Extended X-ray Absorption Fine Structure (EXAFS) fit of the first neighbor demonstrated that for all studied mosses there are ∼4.5 O/N atoms around Cu at ∼1.95 Å likely in a pseudo-square geometry. The X-ray Absorption Near Edge Structure (XANES) analysis demonstrated that Cu(II)-cellulose (representing carboxylate groups) and Cu(II)-phosphate are the main moss surface binding moieties, and the percentage of these sites varies as a function of solution pH. P. patens exposed during one month to Cu{sup 2+} yielded ∼20% of Cu(I) in the form of Cu–S(CN) complexes, suggesting metabolically-controlled reduction of adsorbed and assimilated Cu{sup 2+}.

  10. Chemical and structural characterization of copper adsorbed on mosses (Bryophyta)

    International Nuclear Information System (INIS)

    González, Aridane G.; Jimenez-Villacorta, Felix; Beike, Anna K.; Reski, Ralf; Adamo, Paola; Pokrovsky, Oleg S.

    2016-01-01

    Highlights: • Cu 2+ was adsorbed on four mosses used in moss-bag pollution monitoring technique. • Thermodynamic approach was used to model Cu speciation based on XAS results. • All studied mosses have ∼4.5 O/N atoms at ∼1.95 Å around Cu likely in a pseudo-square geometry. • Cu(II)-carboxylates and Cu(II)-phosphoryls are the main moss surface binding groups. • Moss growing in batch reactor yielded ∼20% of Cu(I) in the form of Cu–S(CN) complexes. - Abstract: The adsorption of copper on passive biomonitors (devitalized mosses Hypnum sp., Sphagnum denticulatum, Pseudoscleropodium purum and Brachythecium rutabulum) was studied under different experimental conditions such as a function of pH and Cu concentration in solution. Cu assimilation by living Physcomitrella patents was also investigated. Molecular structure of surface adsorbed and incorporated Cu was studied by X-ray Absorption Spectroscopy (XAS). Devitalized mosses exhibited the universal adsorption pattern of Cu as a function of pH, with a total binding sites number 0.05–0.06 mmolg dry −1 and a maximal adsorption capacity of 0.93–1.25 mmolg dry −1 for these devitalized species. The Extended X-ray Absorption Fine Structure (EXAFS) fit of the first neighbor demonstrated that for all studied mosses there are ∼4.5 O/N atoms around Cu at ∼1.95 Å likely in a pseudo-square geometry. The X-ray Absorption Near Edge Structure (XANES) analysis demonstrated that Cu(II)-cellulose (representing carboxylate groups) and Cu(II)-phosphate are the main moss surface binding moieties, and the percentage of these sites varies as a function of solution pH. P. patens exposed during one month to Cu 2+ yielded ∼20% of Cu(I) in the form of Cu–S(CN) complexes, suggesting metabolically-controlled reduction of adsorbed and assimilated Cu 2+ .

  11. Photoelectron diffraction studies of small adsorbates on single crystal surfaces

    International Nuclear Information System (INIS)

    Pascal, Mathieu

    2002-01-01

    The structural determination of small molecules adsorbed on single crystal surfaces has been investigated using scanned energy mode photoelectron diffraction (PhD). The experimental PhD data were compared to theoretical models using a simulation program based on multiple scattering calculations. Three adsorption systems have been examined on Ag(110), Cu(110) and Cu(111) crystals. The structure of the (2x1)-O adsorption phase on Ag(110) revealed that the O atoms occupied the long bridge site and are almost co-planar with the top layer of Ag atoms. The best agreement between multiple scattering theory and experiment has been obtained for a missing-row (or equivalently an 'added- row') reconstruction. Alternative buckled-row and unreconstructed surface models can be excluded. The adsorption of the benzoate species on Cu(110) has been found to occur via the carboxylate group. The molecules occupy short bridge sites with the O atoms being slightly displaced from atop sites and are aligned along the close-packed azimuth. The tilt of the molecule with respect to the surface and the degree to which the surface is relaxed have also been investigated. The adsorption of methyl on Cu(111) was studied using either azomethane or methyl iodide to prepare the surface layers. At saturation coverage the preferred adsorption site is the fcc threefold hollow site, whereas at half saturation coverage ∼ 30 % of the methyl species occupy the hop threefold hollow sites. Best agreement between theory and experiment corresponded to a methyl group adsorbed with C 3v symmetry. The height of the C above the surface in a pure methyl layer was 1.66 ± 0.02 A, but was reduced to 1.62 ± 0.02 A in the presence of co-adsorbed iodine, suggesting that iodine increases the strength of adsorption. Iodine was also found to occupy the fee threefold hollow sites with a Cu-l bondlength of 2.61 ± 0.02 A. (author)

  12. Fate of Trace Organic Compounds in Granular Activated Carbon (GAC Adsorbers for Drinking Water Treatment

    Directory of Open Access Journals (Sweden)

    Alexander Sperlich

    2017-06-01

    Full Text Available Granular activated carbon (GAC adsorbers for drinking water treatment were operated for approx. 14 months and the breakthrough of dissolved organic carbon (DOC and trace organic chemicals (TOrCs was monitored. Effluent concentration profiles of gabapentin and valsartan acid increase already at throughputs of <10,000 BV. The corresponding breakthrough curves flatten out without reaching the influent concentration level. This strongly indicates biological degradation of these substances in the GAC adsorbers under aerobic conditions, contributing to a more efficient use of GAC. The observed biodegradation in pilot GAC adsorbers also confirms recent reports of biodegradation of gabapentin and valsartan acid during managed aquifer recharge. Oxypurinol is comparatively well adsorbed and no breakthrough was observed during the experimental period. Adsorption capacity and breakthrough characteristics of oxypurinol appear very similar to carbamazepine. Breakthrough of GAC adsorbers operated with drinking water was compared to those of groundwater-fed adsorbers. The results show, that it is generally advisable to use previously aerated influents for GAC fixed-bed adsorbers because this can substantially improve biological removal of otherwise poorly adsorbable compounds and ensure full GAC accessibility for adsorbates by avoiding the undesirable formation of inorganic precipitates on adsorption sites.

  13. New adsorbents from oil shales. Preparation, characterization and U, Th isotope adsorption tests

    International Nuclear Information System (INIS)

    Khouya, E.; Andres, Y.; Naslain, R.; Pailler, R.; Nourredine, A.

    2004-01-01

    New activated adsorbents for radionuclides have been produced from Moroccan oil shales by pyrolysis of the natural material at 550 deg C flowed by a KMnO 4 activation. The texture and composition of the native rock and the adsorbents were studied before their use in tests for adsorption of radionuclides from standard solutions prepared from uranylnitrate and thorium nitrate in equilibrium with their daughters. The distribution coefficients between solutions containing U, Th and Ra and the adsorbents were evaluated by means of specific activities, measured by γ-ray spectrometry. The adsorbents were observed to eliminate U, Th, Ra, Ac and Tl from aqueous solutions. (author)

  14. Preparation and characterization of a novel electrospun ammonium molybdophosphate/polyacrylonitrile nanofiber adsorbent for cesium removal

    International Nuclear Information System (INIS)

    Amin Tabatabaeefar; Mohammad Ali Moosavian; Ali Reza Keshtkar

    2015-01-01

    Adsorption of Cs + ion from aqueous solution onto a novel electrospun ammonium molybdophosphate/polyacrylonitrile nanofiber adsorbent with variation in AMP content, adsorbent concentration, pH, contact time, initial concentration and temperature was studied. The physicochemical characterization was performed by FTIR, XRD, BET and SEM analyses. Langmuir, Freundlich and Dubinin-Radushkevich models were used for analysis of equilibrium data. Kinetic results showed that the experimental data best fitted the pseudo-second-order kinetic model. The adsorption affinity of metal ions onto adsorbent was in order of Cs + > Co 2+ > Mg 2+ > Ca 2+ > Sr 2+ . The adsorbent could be easily regenerated after five cycles of adsorption-desorption. (author)

  15. Electron shuttle-mediated biotransformation of hexahydro-1,3,5-trinitro-1,3,5-triazine adsorbed to granular activated carbon.

    Science.gov (United States)

    Millerick, Kayleigh; Drew, Scott R; Finneran, Kevin T

    2013-08-06

    Granular activated carbon (GAC) effectively removes hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) from groundwater but generates RDX-laden GAC that must be disposed of or regenerated. Batch reactors containing GAC to which RDX was preadsorbed were used in experiments to test the potential for adsorbed RDX reduction and daughter product formation using (i) chemically reduced anthrahydroquinone-2,6-disulfonate (AH2QDS), (ii) resting Geobacter metallireducens strain GS-15, and (iii) a combined system containing AQDS and GS-15. Approximately 97.0% of the adsorbed RDX was transformed in each of these experimental systems by 90 h. Chemically reduced AQDS (AH2QDS) transformed 99.2% of adsorbed RDX; formaldehyde was produced rapidly and was stoichiometric (3 mol HCHO per mol RDX). Geobacter metallireducens also reduced RDX with and without AQDS present. This is the first study to demonstrate biological transformation of RDX adsorbed to GAC. Formaldehyde increased and then decreased in biological systems, suggesting a previously unreported capacity for G. metallireducens to oxidize formaldehyde, which was confirmed with resting cell suspensions. These data suggest the masses of GAC waste currently produced by activated carbon at RDX remediation sites can be minimized, decreasing the carbon footprint of the treatment technology. Alternatively, this strategy may be used to develop a Bio-GAC system for ex situ RDX treatment.

  16. Calculated bond properties of K adsorbed on graphite

    International Nuclear Information System (INIS)

    Hjortstam, O.; Wills, J.M.; Johansson, B.; Eriksson, O.

    1998-01-01

    The properties of the chemical bond of K adsorbed on a graphite(0001) surface have been studied for different coverages, by means of a full-potential slab method. Specific modifications of the Hamiltonian are performed in order to make it possible to study K on graphite in the disperse phase (dilute limit). It is found that K forms a metallic state when covering a graphite surface with a (2x2) coverage. For a (3x3) coverage as well as in the disperse phase K is found to form an ionic bond with graphite. It is shown that in the disperse phase, the hybridization between the K 4s level and graphite is weak. Our findings are consistent with recent experiments. Furthermore the cohesive energies of K adsorption on graphite are found to be larger in the (2x2) coverage compared to the (3x3) coverage. copyright 1998 The American Physical Society

  17. Recovery of uranium from seawater by composite fiber adsorbent

    International Nuclear Information System (INIS)

    Kubuke, Y.; Aoki, T.; Tanaka, H.; Tabushi, I.; Kamaishi, T.; Hagiwara, I.

    1991-01-01

    The authors of this paper developed a composite fiber adsorbent (CFA) to entrap finely powdered amidoxime into fibrils of supporting material with silica in a previous report. This was further tested for uranyl recovery directly from seawater. The adsorption rate showed a flow rate dependence with almost a saturation value of ∼100 μg of U/g of CFA at a mean flow rate of sea current. Chemical as well as physical deterioration was overcome by using 1 N NaHCO 3 and 0.72 M NaCl as liberating and washing agents, to keep the pH and ionic strength, respectively, constant, and the initial adsorption rate was maintained even after a recycle time of 50. A continuous passage of seawater showed a linear increase of the adsorption to afford 1560 μg of U/g of CFA after 3 weeks

  18. Gamma radiation-polymerized methacrylates used as heavy metals adsorbents

    International Nuclear Information System (INIS)

    Barrera D, C.; Roa M, G.; Balderas H, P.; Bilyeu, B.; Urena N, F.

    2009-01-01

    Heavy metal removal from aqueous solution is a priority research area since the actual methods are costly and a major drawback is the large amounts of sludge generated when applying traditional techniques. Adsorption is a physiochemical wastewater treatment process, which is gaining prominence as a means of producing high quality effluents, which are low in metal ion concentrations. The development of inexpensive adsorbents for the treatment of wastewater is an important area in environmental sciences. In this work we describe some of the physical and chemical phenomena that take place in the polymerization of methacrylates when gamma radiation is used. We explain how polymeric material characterization equipment are used for obtaining information regarding the material properties. Then we explain how the new polymeric material obtained can be use for the wastewater treatment. Finally, a comparison in the heavy metal removal from aqueous solution with other sorbent materials is presented. (Author)

  19. Charge transfer properties of pentacene adsorbed on silver: DFT study

    Energy Technology Data Exchange (ETDEWEB)

    N, Rekha T.; Rajkumar, Beulah J. M., E-mail: beulah-rajkumar@yahoo.co.in [PG & Research Department of Physics, Lady Doak College, Madurai 625002 (India)

    2015-06-24

    Charge transfer properties of pentacene adsorbed on silver is investigated using DFT methods. Optimized geometry of pentacene after adsorption on silver indicates distortion in hexagonal structure of the ring close to the silver cluster and deviations in co-planarity of carbon atoms due to the variations in bond angles and dihedral angles. Theoretically simulated absorption spectrum has a symmetric surface plasmon resonance peak around 486nm corresponding to the transfer of charge from HOMO-2 to LUMO. Theoretical SERS confirms the process of adsorption, tilted orientation of pentacene on silver surface and the charge transfers reported. Localization of electron density arising from redistribution of electrostatic potential together with a reduced bandgap of pentacene after adsorption on silver suggests its utility in the design of electro active organic semiconducting devices.

  20. Porous silicon powder as an adsorbent of heavy metal (nickel)

    Science.gov (United States)

    Nabil, Marwa; Motaweh, Hussien A.

    2018-04-01

    New and inexpensive nanoporous silicon (NPS) powder was prepared by alkali chemical etching using sonication technique and was subsequently investigated as an adsorbent in batch systems for the adsorption Ni(II) ions in an aqueous solution. The optimum conditions for the Ni(II) ion adsorption capacity of the NPS powder were studied in detail by varying parameters such as the initial Ni(II) concentration, the solution pH value, the adsorption temperature and contact time. The results indicated that the maximum adsorption capacity and the maximum removal percent of Ni(II) reached 2665.33 mg/g and 82.6%, respectively, at an initial Ni(II) concentration of 100 mg/L, adsorption time of 30 min and no effect of the solution pH and adsorption temperature.

  1. Ballistic thermophoresis of adsorbates on free-standing graphene.

    Science.gov (United States)

    Panizon, Emanuele; Guerra, Roberto; Tosatti, Erio

    2017-08-22

    The textbook thermophoretic force which acts on a body in a fluid is proportional to the local temperature gradient. The same is expected to hold for the macroscopic drift behavior of a diffusive cluster or molecule physisorbed on a solid surface. The question we explore here is whether that is still valid on a 2D membrane such as graphene at short sheet length. By means of a nonequilibrium molecular dynamics study of a test system-a gold nanocluster adsorbed on free-standing graphene clamped between two temperatures [Formula: see text] apart-we find a phoretic force which for submicron sheet lengths is parallel to, but basically independent of, the local gradient magnitude. This identifies a thermophoretic regime that is ballistic rather than diffusive, persisting up to and beyond a 100-nanometer sheet length. Analysis shows that the phoretic force is due to the flexural phonons, whose flow is known to be ballistic and distance-independent up to relatively long mean-free paths. However, ordinary harmonic phonons should only carry crystal momentum and, while impinging on the cluster, should not be able to impress real momentum. We show that graphene and other membrane-like monolayers support a specific anharmonic connection between the flexural corrugation and longitudinal phonons whose fast escape leaves behind a 2D-projected mass density increase endowing the flexural phonons, as they move with their group velocity, with real momentum, part of which is transmitted to the adsorbate through scattering. The resulting distance-independent ballistic thermophoretic force is not unlikely to possess practical applications.

  2. Removal of Cobalt Ion by Adsorbing Colloidal Flotation

    Energy Technology Data Exchange (ETDEWEB)

    Jung, In Ha; Lee, Jung Won [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-09-30

    Simulated waste liquid containing 50 ppm cobalt ion was treated by adsorbing colloidal flotation using Fe(III) or Al(III) as flocculant and a sodium lauryl sulfate as a collector. Parameters such as pH, surfactant concentration, Fe(III) or Al(III) concentration, gas flow rate, etc., were considered. The flotation with Fe(III) showed 99.8% removal efficiency of cobalt on the conditions of initial cobalt ion concentration 50 ppm, pH 9.5, gas flow rate 70 ml/min, and flotation time 30 min. When the waste solution was treated with 35% H{sub 2}O{sub 2} prior to adsorbing colloidal flotation, the optimal pH for removing cobalt shifted to weak alkaline range and flotation could be applied in wider range of pH as compared to non-use of H{sub 2}O{sub 2}. Additional use of 20 ppm Al(III) after precipitation of 50 ppm Co(II) with 50 ppm Fe(III) made the optimal pH range for preferable flotation wider. Foreign ions such as, NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, Na{sup +}, Ca{sup 2+} were adopted and their effects were observed, Of which sulfate ion was found to be detrimental to removal of cobalt ion by flotation. Coprecipitation of Co ion with Fe(III) and Al(III) resulted in better removal efficiency of cobalt ion in the presence of sulfate ion. (author). 14 refs., 13 figs.

  3. Evaluation of {sup 131}I retention in several adsorbers

    Energy Technology Data Exchange (ETDEWEB)

    Catanoso, Marcela F.; Osso Junior, Joao Alberto, E-mail: marcela.forli@gmail.co, E-mail: jaosso@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Diretoria de Radiofarmacia

    2011-07-01

    Several iodine radioisotopes are used in nuclear medicine for treatment and diagnostic purposes. The radioisotope {sup 131}I is used both in diagnosis and therapy due to its physical characteristics of decay by {beta}{sup -} and its {gamma}-ray emissions suitable for diagnosis. It is routinely produced at IPEN through the irradiation of TeO{sub 2} targets in the IEA-R1m nuclear reactor. After the irradiation, the {sup 131}I is separated by dry distillation, where the targets are put in an oven, heated at 760 deg C for 2 hours and the {sup 131}I, volatile, is carried by an O{sub 2} gas stream. The aim of this work was to evaluate the retention and elution of {sup 131}I samples produced at IPEN in several adsorbers as part of a project aiming the purification of these radioisotopes, allowing the labeling of biomolecules. Samples of {sup 131}I were used for retention and elution studies with the following adsorbers: commercial cartridges, anionic resin columns and cationic resin column. The results showed that Ag cartridges and anionic resins Dowex 1X8, Dowex 3 and IRA 400 had a great iodine retention but no elution after using specific eluents. The QMA light, acid alumina, neutral alumina and cationic resin Dowex 50WX4 showed high retention and elution and QMA plus and cationic resin Dowex 50WX8 and Dowex 50WX12 had a good retention but lower elution. Regarding to the better retention and elution, Ag cartridges and resins showed a higher percentage of iodine retention but lower elution yield and QMA light, acid and neutral alumina cartridges showed better results. (author)

  4. Band mapping of surface states vs. adsorbate coverage

    International Nuclear Information System (INIS)

    Rotenberg, E.; Kevan, S.D.; Denlinger, J.D.; Chung, Jin-Wook

    1997-01-01

    The theory of electron bands, which arises from basic quantum mechanical principles, has been the cornerstone of solid state physics for over 60 years. Simply put, an energy band is an electron state in a solid whose energy varies with its momentum (similar to, but with a more complicated dependence than, how a free electron's energy is proportional to its momentum squared). Much attention over the last 15 years has been given to the study of band structure of surfaces and interfaces, especially as the applications of these two-dimensional systems have become increasingly important to industry and science. The ultraESCA endstation at beamline 7.01 at the Advanced Light Source was developed for very high-energy - (∼50 meV) and angular - ( 12 photons/sec) makes the detailed study of the evolution of bands possible. The authors are interested in learning how, when one forms a chemical bond between a metal and an overlaying atom or molecule, the resulting charge transfer to or from the adsorbate affects the surface bands. In some cases of interest, intermediate coverages lead to different band structure than at the extremes of clean and saturated surfaces. Surfaces of tungsten are particularly interesting, as their atomic geometry has been shown to be exquisitely sensitive to both the surface vibrational and electronic properties. In this study, the authors looked at the surface bands of tungsten ((110) surface), as a function both of coverage and mass of overlaying atoms. The adsorbed atoms were hydrogen and the alkali atoms lithium and cesium

  5. Evaluation of 131I retention in several adsorbers

    International Nuclear Information System (INIS)

    Catanoso, Marcela F.; Osso Junior, Joao Alberto

    2011-01-01

    Several iodine radioisotopes are used in nuclear medicine for treatment and diagnostic purposes. The radioisotope 131 I is used both in diagnosis and therapy due to its physical characteristics of decay by β - and its γ-ray emissions suitable for diagnosis. It is routinely produced at IPEN through the irradiation of TeO 2 targets in the IEA-R1m nuclear reactor. After the irradiation, the 131 I is separated by dry distillation, where the targets are put in an oven, heated at 760 deg C for 2 hours and the 131 I, volatile, is carried by an O 2 gas stream. The aim of this work was to evaluate the retention and elution of 131 I samples produced at IPEN in several adsorbers as part of a project aiming the purification of these radioisotopes, allowing the labeling of biomolecules. Samples of 131 I were used for retention and elution studies with the following adsorbers: commercial cartridges, anionic resin columns and cationic resin column. The results showed that Ag cartridges and anionic resins Dowex 1X8, Dowex 3 and IRA 400 had a great iodine retention but no elution after using specific eluents. The QMA light, acid alumina, neutral alumina and cationic resin Dowex 50WX4 showed high retention and elution and QMA plus and cationic resin Dowex 50WX8 and Dowex 50WX12 had a good retention but lower elution. Regarding to the better retention and elution, Ag cartridges and resins showed a higher percentage of iodine retention but lower elution yield and QMA light, acid and neutral alumina cartridges showed better results. (author)

  6. Electrochemical Properties of Alkanethiol Monolayers Adsorbed on Nanoporous Au Surfaces

    International Nuclear Information System (INIS)

    Chu, Yeon Yi; Seo, Bora; Kim, Jong Won

    2010-01-01

    We investigated the electrochemical properties of alkanethiol monolayers adsorbed on NPG surfaces by cyclic voltammetry and electrochemical impedance spectroscopy, and the results are compared to those on flat Au surfaces. The reductive desorption of alkanethiols on NPG surfaces is observed in more negative potential regions than that on flat Au surfaces due the stronger S-Au interaction on NPG surfaces. While the electron transfer through alkanethiol monolayers on flat Au surfaces occurs via a tunneling process through the monolayer films, the redox species can permeate through the monolayers on NPG surfaces to transfer the electrons to the Au surfaces. The results presented here will help to elucidate the intrinsic electrochemical properties of alkanethiol monolayers adsorbed on curved Au surfaces, particularly on the surface of AuNPs. Self-assembled monolayers (SAMs) of thiolate molecules on Au surfaces have been the subject of intensive research for the last few decades due to their unique physical and chemical properties. The well-organized surface structures of thiolate SAMs with various end-group functionalities can be further utilized for many applications in biology and nanotechnology. In addition to the practical applications, SAMs of thiolate molecules on Au surfaces also provide unique opportunities to address fundamental issues in surface chemistry such as self-organized surface structures, electron transfer behaviors, and moleculesubstrate interactions. Although there have been numerous reports on the fundamental physical and chemical properties of thiolate SAMs on Au surfaces, most of them were investigated on flat Au surfaces, typically on well-defined Au(111) surfaces

  7. Waste biomass adsorbents for copper removal from industrial wastewater--a review.

    Science.gov (United States)

    Bilal, Muhammad; Shah, Jehanzeb Ali; Ashfaq, Tayyab; Gardazi, Syed Mubashar Hussain; Tahir, Adnan Ahmad; Pervez, Arshid; Haroon, Hajira; Mahmood, Qaisar

    2013-12-15

    Copper (Cu(2+)) containing wastewaters are extensively released from different industries and its excessive entry into food chains results in serious health impairments, carcinogenicity and mutagenesis in various living systems. An array of technologies is in use to remediate Cu(2+) from wastewaters. Adsorption is the most attractive option due to the availability of cost effective, sustainable and eco-friendly bioadsorbents. The current review is dedicated to presenting state of the art knowledge on various bioadsorbents and physico-chemical conditions used to remediate Cu(2+) from waste streams. The advantages and constraints of various adsorbents were also discussed. The literature revealed the maximum Cu adsorption capacities of various bioadsorbents in the order of algae>agricultural and forest>fungal>bacterial>activated carbon>yeast. However, based on the average Cu adsorption capacity, the arrangement can be: activated carbon>algal>bacterial>agriculture and forest-derived>fungal>yeast biomass. The data of Cu removal using these bioadsorbents were found best fit both Freundlich and Langmuir models. Agriculture and forest derived bioadsorbents have greater potential for Cu removal because of higher uptake, cheaper nature, bulk availability and mono to multilayer adsorption behavior. Higher costs at the biomass transformation stage and decreasing efficiency with desorption cycles are the major constraints to implement this technology. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Chitosan scaffold as an alternative adsorbent for the removal of hazardous food dyes from aqueous solutions.

    Science.gov (United States)

    Esquerdo, V M; Cadaval, T R S; Dotto, G L; Pinto, L A A

    2014-06-15

    The dye adsorption with chitosan is considered an eco-friendly alternative technology in relation to the existing water treatment technologies. However, the application of chitosan for dyes removal is limited, due to its low surface area and porosity. Then we prepared a chitosan scaffold with a megaporous structure as an alternative adsorbent to remove food dyes from solutions. The chitosan scaffold was characterized by infrared spectroscopy, scanning electron microscopy and structural characteristics. The potential of chitosan scaffold to remove five food dyes from solutions was investigated by equilibrium isotherms and thermodynamic study. The scaffold-dyes interactions were elucidated, and desorption studies were carried out. The chitosan scaffold presented pore sizes from 50 to 200 μm, porosity of 92.2±1.2% and specific surface area of 1135±2 m(2) g(-1). The two-step Langmuir model was suitable to represent the equilibrium data. The adsorption was spontaneous, favorable, exothermic and enthalpy-controlled process. Electrostatic interactions occurred between chitosan scaffold and dyes. Desorption was possible with NaOH solution (0.10 mol L(-1)). The chitosan megaporous scaffold showed good structural characteristics and high adsorption capacities (788-3316 mg g(-1)). Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Graphene nanosheets as novel adsorbents in adsorption, preconcentration and removal of gases, organic compounds and metal ions

    International Nuclear Information System (INIS)

    Yu, Jin-Gang; Yu, Lin-Yan; Yang, Hua; Liu, Qi; Chen, Xiao-Hong; Jiang, Xin-Yu; Chen, Xiao-Qing; Jiao, Fei-Peng

    2015-01-01

    Due to their high adsorption capacities, carbon-based nanomaterials such as carbon nanotubes, activated carbons, fullerene and graphene are widely used as the currently most promising functional materials. Since its discovery in 2004, graphene has exhibited great potential in many technological fields, such as energy storage materials, supercapacitors, resonators, quantum dots, solar cells, electronics, and sensors. The large theoretical specific surface area of graphene nanosheets (2630 m 2 ·g −1 ) makes them excellent candidates for adsorption technologies. Further, graphene nanosheets could be used as substrates for decorating the surfaces of nanoparticles, and the corresponding nanocomposites could be applied as novel adsorbents for the removal of low concentrated contaminants from aqueous solutions. Therefore, graphene nanosheets will challenge the current existing adsorbents, including other types of carbon-based nanomaterials. - Highlights: • The recent progress of application of graphene in adsorption was presented. • The design and practical application of graphene based composites was discussed. • The future trends and prospects of graphene were analyzed and proposed

  10. Graphene nanosheets as novel adsorbents in adsorption, preconcentration and removal of gases, organic compounds and metal ions

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Jin-Gang, E-mail: yujg@csu.edu.cn [College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083 (China); College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082 (China); Yu, Lin-Yan; Yang, Hua; Liu, Qi [College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083 (China); Chen, Xiao-Hong [Collaborative Innovation Center of Resource-conserving and Environment-friendly Society and Ecological Civilization, Changsha, Hunan 410083 (China); Jiang, Xin-Yu [College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083 (China); Chen, Xiao-Qing, E-mail: xqchen@csu.edu.cn [College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083 (China); Jiao, Fei-Peng, E-mail: jiaofp@163.com [College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083 (China)

    2015-01-01

    Due to their high adsorption capacities, carbon-based nanomaterials such as carbon nanotubes, activated carbons, fullerene and graphene are widely used as the currently most promising functional materials. Since its discovery in 2004, graphene has exhibited great potential in many technological fields, such as energy storage materials, supercapacitors, resonators, quantum dots, solar cells, electronics, and sensors. The large theoretical specific surface area of graphene nanosheets (2630 m{sup 2}·g{sup −1}) makes them excellent candidates for adsorption technologies. Further, graphene nanosheets could be used as substrates for decorating the surfaces of nanoparticles, and the corresponding nanocomposites could be applied as novel adsorbents for the removal of low concentrated contaminants from aqueous solutions. Therefore, graphene nanosheets will challenge the current existing adsorbents, including other types of carbon-based nanomaterials. - Highlights: • The recent progress of application of graphene in adsorption was presented. • The design and practical application of graphene based composites was discussed. • The future trends and prospects of graphene were analyzed and proposed.

  11. The synthesis of a new type adsorbent for the removal of toxic gas by radiation-induced graft polymerization

    International Nuclear Information System (INIS)

    Okamoto, Jiro; Sugo, Takanobu

    1990-01-01

    A new type of adsorbent containing sulfuric acid group for the removal of ammonia gas was synthesized by radiation-induced graft polymerization of styrene onto fibrous and nonwoven type polypropylene followed by sulufonation with chlorosulfonic acid. The rate of the adsorption of ammonia gas by H-type adsorbent is independent of the ion-exchange capacity. The amount of ammonia gas adsorbed by the chemical adsorption was dependent on the ion-exchange capacity of H-type fibrous adsorbent and was kept constant value in spite of the equilibrium pressure of ammonia gas. Cu(II)- and Ni(II)-types fibrous adsorbent were prepared by the ion exchange reaction of Na-type fibrous adsorbent with metal nitrate solutions. Although, the rate of adsorption of ammonia gas by metal-type fibrous adsorbent is lower than that of H-type adsorbent, the amount of ammonia gas adsorbed increases compared to H-type adsorbent with the same ion exchange capacity. It was related to the highest coordination number of metal ion. The ratio of the number of ammonia molecules adsorbed chemically and the number of metal ion adsorbed in fibrous adsorbent was 4 for Cu-type and 6 for Ni-type fibrous adsorbent, respectively. (author)

  12. Effect of uncertainty in pore volumes on the uncertainty in amount adsorbed at high-pressures on activated carbon cloth

    International Nuclear Information System (INIS)

    Pendleton, Ph.; Badalyan, A.

    2005-01-01

    determination on the adsorption capacity and the specific surface excess on FMI/250 ACC at high-pressures, assess the extent of hysteresis in the pore volume and size distribution as a result of low-high-low pressure cycling, and show the influence of chemisorbed oxygen on the amount adsorbed and the materials physical property values. [1] E. Dimotakis, M. P. Cal, J. Economy, M. J. Rood, S. Larson, Environmental Science and Technology, 29, 1876,1995. [2] D. Lozano-Castello, J. Alcaniz-Monge, M. A. de la Casa-Lillo, D. Cazorla-Amoros, A. Linares-Solano, Fuel, 81, 1777, 2 002. [3] Sh. Jiang, J. A. Zollweg, K. E. Gubbins, Journal of Physical Chemistry, 98, 5709,1994. (authors)

  13. Design, construction and test run of a solid adsorption solar refrigerator using activated carbon/methanol, as adsorbent/adsorbate pair

    International Nuclear Information System (INIS)

    Anyanwu, E.E.; Ezekwe, C.I.

    2003-01-01

    The design, construction and test run of a solid adsorption solar refrigerator are presented. It used activated carbon/methanol as the adsorbent/adsorbate pair. The refrigerator has three major components: collector/generator/adsorber, condenser and evaporator. Its flat plate type collector/generator/adsorber used clear plane glass sheet of effective exposed area of 1.2 m 2 . The steel condenser tube with a square plan view was immersed in pool of stagnant water contained in a reinforced sandcrete tank. The evaporator is a spirally coiled copper tube immersed in stagnant water. Adsorbent cooling during the adsorption process is both by natural convection of air over the collector plate and tubes and night sky radiation facilitated by removing the collector box end cover plates. Ambient temperatures during the adsorbate generation and adsorption process varied over 18.5-34 deg. C. The refrigerator yielded evaporator temperatures ranging over 1.0-8.5 deg. C from water initially in the temperature range 24-28 deg. C. Accordingly, the maximum daily useful cooling produced was 266.8 kJ/m 2 of collector area

  14. Effectiveness of solar heating systems for the regeneration of adsorbents in recessed fruit and vegetable storages

    International Nuclear Information System (INIS)

    Khuzhakulov, S.M.; Uzakov, G.N.; Vardiyashvili, A.B

    2013-01-01

    A new method for the regeneration of adsorbents using solar heating systems is proposed. It provides energy saving through the control of the gas composition and humidity in recessed fruit and vegetable storages. The effectiveness of solar heating systems, such as a 'hot box' for the regeneration of adsorbents in fruit and vegetable storages is shown. (author)

  15. Nicotinic acid as a new co-adsorbent in dye-sensitized solar cells

    DEFF Research Database (Denmark)

    Nguyen, Phuong Tuyet; Nguyen, Vinh Son; Pham Phan, Thu Anh

    2017-01-01

    With the aim of introduction a new inexpensive co-adsorbent to improve solar cell performance, the influence of nicotinic acid (NTA) used as a co-adsorbent in dye-sensitized solar cells (DSCs) was investigated. The findings showed that low concentrations of NTA (

  16. An eco-friendly approach for heavy metal adsorbent regeneration using CO2-responsive molecular octopus.

    Science.gov (United States)

    Bai, Yu; Liang, Yen Nan; Hu, Xiao

    2017-10-01

    Perennial problems of adsorption in wastewater treatment include adsorbent recycling, generation of waste sludge and secondary pollution because harmful concentrated acids, bases or strong chelators are often used for adsorbent regeneration and adsorbate recovery. We report, for the first time, an eco-friendly regeneration concept demonstrated with a CO 2 -responsive octopus-like polymeric adsorbent. Various heavy metals can be scavenged at very high Q e by such adsorbent through coordination. Most importantly, the rapid and complete regeneration of the adsorbent and recovery of the heavy metal ions can be readily achieved by CO 2 bubbling within a few minutes under mild conditions, i.e., room temperature and atmospheric pressure. The adsorbent can then be restored to its adsorptive state and reused upon removal of CO 2 by simply bubbling another gas. This eco-friendly, effective, ultra-fast and repeatable CO 2 -triggered regeneration process using CO 2 -responsive adsorbent with versatile structure, morphology or form can be incorporated into a sustainable closed-loop wastewater treatment process to solve the perennial problems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Adsorptive desulfurization of model oil using untreated, acid activated and magnetite nanoparticle loaded bentonite as adsorbent

    Directory of Open Access Journals (Sweden)

    Muhammad Ishaq

    2017-02-01

    Full Text Available The present research work focuses on a novel ultraclean desulfurization process of model oil by the adsorption method using untreated, acid activated and magnetite nanoparticle loaded bentonite as adsorbent. The parameters investigated are effect of contact time, adsorbent dose, initial dibenzothiophene (DBT concentration and temperature. Experimental tests were conducted in batch process. Pseudo first and second order kinetic equations were used to examine the experimental data. It was found that pseudo second order kinetic equation described the data of the DBT adsorption onto all types of adsorbents very well. The isotherm data were analyzed using Langmuir and Freundlich isotherm models. The Langmuir isotherm model fits the data very well for the adsorption of DBT onto all three forms of adsorbents. The adsorption of DBT was also investigated at different adsorbent doses and was found that the percentage adsorption of DBT was increased with increasing the adsorbent dose, while the adsorption in mg/g was decreased with increasing the adsorbent dose. The prepared adsorbents were analyzed by scanning electron microscopy (SEM, energy dispersive X-ray spectrometry (EDX and X-ray diffraction (XRD.

  18. The development of an adsorbent for corrosion products in high-temperature water

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Ik; Sung, Ki Woung; Kim, Kwang Rag; Kim, Yu Hwan; Koo, Jae Hyoo [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-08-01

    In order to use as adsorbent for removal of the soluble corrosion products, mainly Co{sup 60} under PWR reactor coolant conditions (300 deg C, 160 kg/cm{sup 2}), stable ZrO{sub 2} adsorbent was prepared using sol-gel process from zirconyl nitrate, AlO adsorbent was prepared by hydrolysis of aluminum isopropoxide, and titanium tetraisopropoxide, respectively. The prepared adsorbents were calcined at various temperature and analyzed by physical properties and the Co{sup 2+} adsorption capacity. And it was shown that the Co{sup 2+} adsorption capacity of the TiO{sub 2}-Al{sub 2}O{sub 3} adsorbents were found to have larger than that of ZrO{sub 2} and Al{sub 2}O{sub 3} adsorbents in high-temperature water. ZrO{sub 2}, Al{sub 2}O{sub 3} and TiO{sub 2}-Al{sub 2}O{sub 3} adsorbents were found to be suitable high-temperature adsorbents for the removal of dissolved corrosion products, mainly Co in PWR reactor coolant conditions. 15 tabs., 51 figs., 55 refs. (Author).

  19. Removal of VOCs from air stream with corrugated sheet as adsorbent

    Directory of Open Access Journals (Sweden)

    Rabia Arshad

    2016-10-01

    Full Text Available A large proportional of volatile organic compounds (VOCs are released into the environment from various industrial processes. The current study elucidates an application of a simple adsorption phenomenon for removal of three main types of VOCs, i.e., benzene, xylene and toluene, from an air stream. Two kinds of adsorbents namely acid digested adsorbent and activated carbon are prepared to assess the removal efficiency of each adsorbent in the indoor workplace environment. The results illustrate that the adsorbents prepared from corrugated sheets were remarkably effective for the removal of each pollutant type. Nevertheless, activated carbon showed high potential of adsorbing the targeted VOC compared to the acid digested adsorbent. The uptake by the adsorbents was in the following order: benzene > xylene > toluene. Moreover, maximum adsorption of benzene, toluene and xylene occurred at 20 °C and 1.5 cm/s for both adsorbents whereas minimum success was attained at 30 °C and 1.0 cm/s. However, adsorption pattern are found to be similar for each of the the three aromatic hydrocarbons. It is concluded that the corrugated sheets waste can be a considered as a successful and cost-effective solution towards effective removal of targeted pollutants in the air stream.

  20. Examination of uranium recovery technique from sea water using natural components for adsorbent

    International Nuclear Information System (INIS)

    Tanaka, Nobuyuki; Masaki, Hiroyuki; Shimizu, Takao; Tokiwai, Moriyasu

    2010-01-01

    In this study, we investigated the potency of natural components as adsorbent for uranium recovery from seawater. In addition, cost evaluation of uranium recovery from seawater using natural components for adsorbents was performed. Furthermore, new ideas on reservation system of adsorbents at sea area were proposed. Several poly-phenols were selected as adsorbent reagents, then they were adsorbed on the support such as cotton fiber by several methods as the followings; chemical syntheses, electrical beam irradiation, and traditional dyeing. As a result, the adsorbent made by traditional dyeing method using gallnut tannin as natural component, was showed high performance for uranium recovery from seawater on only the first. It was evaluated that traditional dyeing method had also advantage in the manufacturing cost, comparing with earlier method. Additionally, it was considered that reservation system of adsorbent at sea was able to be simplified compared with earlier system. Consequently, uranium recovery from sea water using natural components as adsorbent proposed in this study had a potency of practical use. (author)

  1. Coal and Zea mays cob waste as adsorbents for removal of metallic ...

    African Journals Online (AJOL)

    The efficiency of coal (CO) and Zea mays (ZM) cob adsorbents for the removal of metallic ions from wastewater is reported. The adsorbents were used in both their granular (GCO and GZM) and powdered (PCO and PZM) forms respectively. Chromium, nickel, iron and cadmium were used as model ions. Efficiency of the ...

  2. Copper and zinc removal from roof runoff: from research to full-scale adsorber systems.

    Science.gov (United States)

    Steiner, M; Boller, M

    2006-01-01

    Large, uncoated copper and zinc roofs cause environmental problems if their runoff is infiltrated into the underground or discharged into receiving waters. Since source control is not always feasible, barrier systems for efficient copper and zinc removal are recommended in Switzerland. During the last few years, research carried out in order to test the performance of GIH-calcite adsorber filters as a barrier system. Adsorption and mass transport processes were assessed and described in a mathematical model. However, this model is not suitable for practical design, because it does not give explicit access to design parameters such as adsorber diameter and adsorber bed depth. Therefore, for e.g. engineers, an easy to use design guideline for GIH-calcite adsorber systems was developed, mainly based on the mathematical model. The core of this guideline is the design of the depth of the GIH-calcite adsorber layer. The depth is calculated by adding up the GIH depth for sorption equilibrium and the depth for the mass transfer zone (MTZ). Additionally, the arrangement of other adsorber system components such as particle separation and retention volume was considered in the guideline. Investigations of a full-scale adsorber confirm the successful application of this newly developed design guideline for the application of GIH-calcite adsorber systems in practice.

  3. Effect of adsorbents and chemical treatments on the removal of strontium from aqueous solutions

    International Nuclear Information System (INIS)

    Ahmadpour, A.; Zabihi, M.; Tahmasbi, M.; Bastami, T. Rohani

    2010-01-01

    In the present investigation, three different solid wastes namely almond green hull, eggplant hull, and moss were initially treated and used as adsorbents for the adsorption of strontium ion from aqueous solutions. Adsorbent types and chemical treatments are proved to have effective roles on the adsorption of Sr(II) ion. Among the three adsorbents, almond green hull demonstrated strong affinity toward strontium ion in different solutions. The effectiveness of this new adsorbent was studied in batch adsorption mode under a variety of experimental conditions such as: different chemical treatments, various amounts of adsorbent, and initial metal-ion concentration. The optimum doses of adsorbent for the maximum Sr(II) adsorption were found to be 0.2 and 0.3 g for 45 and 102 mg L -1 solutions, respectively. High Sr(II) adsorption efficiencies were achieved only in the first 3 min of adsorbent's contact time. The kinetics of Sr(II) adsorption on almond green hull was also examined and it was observed that it follows the pseudo second-order behavior. Both Langmuir and Freundlich models well predicted the experimental adsorption isotherm data. The maximum adsorption capacity on almond green hull was found to be 116.3 mg g -1 . The present study also confirmed that these low cost agriculture byproducts could be used as efficient adsorbents for the removal of strontium from wastewater streams.

  4. Adsorbed polymers in aqueous media. The relation between zeta-potential, layer thickness and ionic strength

    NARCIS (Netherlands)

    Cohen Stuart, M.A.; Mulder, J.W.

    1985-01-01

    Streaming potentials for glass capillaries with and without adsorbed poly(vinyl pyrrolidone) were used to determine the thickness of the adsorbed polymer layer. It was found that the thickness determined in this way is a strong function of the ionic strength of the solution. The results are compared

  5. The development of an adsorbent for corrosion products in high-temperature water

    International Nuclear Information System (INIS)

    Kim, Yong Ik; Sung, Ki Woung; Kim, Kwang Rag; Kim, Yu Hwan; Koo, Jae Hyoo

    1996-08-01

    In order to use as adsorbent for removal of the soluble corrosion products, mainly Co 60 under PWR reactor coolant conditions (300 deg C, 160 kg/cm 2 ), stable ZrO 2 adsorbent was prepared using sol-gel process from zirconyl nitrate, AlO adsorbent was prepared by hydrolysis of aluminum isopropoxide, and titanium tetraisopropoxide, respectively. The prepared adsorbents were calcined at various temperature and analyzed by physical properties and the Co 2+ adsorption capacity. And it was shown that the Co 2+ adsorption capacity of the TiO 2 -Al 2 O 3 adsorbents were found to have larger than that of ZrO 2 and Al 2 O 3 adsorbents in high-temperature water. ZrO 2 , Al 2 O 3 and TiO 2 -Al 2 O 3 adsorbents were found to be suitable high-temperature adsorbents for the removal of dissolved corrosion products, mainly Co in PWR reactor coolant conditions. 15 tabs., 51 figs., 55 refs. (Author)

  6. Thermal properties of polyfurfuryl alcohol absorbed/adsorbed on arylated soy protein films

    CSIR Research Space (South Africa)

    Kumar, R

    2012-02-01

    Full Text Available In this study, polyfurfuryl alcohol was absorbed/adsorbed on soy protein isolate films by immersing the SPI films in acid-catalysed furfuryl alcohol solution for 60 h followed by complete curing at 145–150 -C for 2 h. PFA absorbed/adsorbed soy...

  7. Development of Novel CO2 Adsorbents for Capture of CO2 from Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Fauth, D.J.; Filburn, T.P. (University of Hartford, West Hartford, CT); Gray, M.L.; Hedges, S.W.; Hoffman, J.; Pennline, H.W.; Filburn, T.

    2007-06-01

    Capturing CO2 emissions generated from fossil fuel-based power plants has received widespread attention and is considered a vital course of action for CO2 emission abatement. Efforts are underway at the Department of Energy’s National Energy Technology Laboratory to develop viable energy technologies enabling the CO2 capture from large stationary point sources. Solid, immobilized amine sorbents (IAS) formulated by impregnation of liquid amines within porous substrates are reactive towards CO2 and offer an alternative means for cyclic capture of CO2 eliminating, to some degree, inadequacies related to chemical absorption by aqueous alkanolamine solutions. This paper describes synthesis, characterization, and CO2 adsorption properties for IAS materials previously tested to bind and release CO2 and water vapor in a closed loop life support system. Tetraethylenepentamine (TEPA), acrylonitrile-modified tetraethylenepentamine (TEPAN), and a single formulation consisting of TEPAN and N, N’-bis(2-hydroxyethyl)ethylenediamine (BED) were individually supported on a poly (methyl methacrylate) (PMMA) substrate and examined. CO2 adsorption profiles leading to reversible CO2 adsorption capacities were obtained using thermogravimetry. Under 10% CO2 in nitrogen at 25°C and 1 atm, TEPA supported on PMMA over 60 minutes adsorbed ~3.2 mmol/g{sorbent} whereas, TEPAN supported on PMMA along with TEPAN and BED supported on PMMA adsorbed ~1.7 mmol/g{sorbent} and ~2.3 mmol/g{sorbent} respectively. Cyclic experiments with a 1:1 weight ratio of TEPAN and BED supported on poly (methyl methacrylate) beads utilizing a fixed-bed flow system with 9% CO2, 3.5% O2, nitrogen balance with trace gas constituents were studied. CO2 adsorption capacity was ~ 3 mmols CO2/g{sorbent} at 40°C and 1.4 atm. No beneficial effect on IAS performance was found using a moisture-laden flue gas mixture. Tests with 750 ppmv NO in a humidified gas stream revealed negligible NO sorption onto the IAS. A high SO2

  8. Synthesis of Hydrophilic Sulfur-Containing Adsorbents for Noble Metals Having Thiocarbonyl Group Based on a Methacrylate Bearing Dithiocarbonate Moieties

    Directory of Open Access Journals (Sweden)

    Haruki Kinemuchi

    2018-01-01

    Full Text Available Novel hydrophilic sulfur-containing adsorbents for noble metals were prepared by the radical terpolymerization of a methacrylate bearing dithiocarbonate moieties (DTCMMA, hydrophilic monomers, and a cross-linker. The resulting adsorbents efficiently and selectively adsorbed noble metals (Au, Ag, and Pd from various multielement aqueous solutions at room temperature owing to the thiocarbonyl group having high affinity toward noble metals. The metal adsorption by the adsorbents was proceeded by simple mixing followed by filtration. The noble metal selectivity of the adsorbent obtained from DTCMMA and N-isopropylacrylamide was higher than that of the adsorbent obtained from DTCMMA and N,N-dimethylacrylamide due to the lower nonspecific adsorption.

  9. Evaluation of Macronet polymeric adsorbents for removal of PAHs from contaminated soil and groundwater

    International Nuclear Information System (INIS)

    Valderrama, C.; Gamisans, X.; Lao, C.; Farran, A.; Cortina, J.L.

    2005-01-01

    Polycyclic aromatic hydrocarbons (PAHs) represent the largest group of compounds that are mutagenic, carcinogenic, and teratogenic and are included in the priority pollutants lists. Despite their widespread distributions, PAHs can be ultimately deposited and persisted in bed sediments in the aquatic system. This is due largely to the fact that most PAHs sorb strongly to sediments because of their high hydrophobicity, and are resistant to bacterial degradation under anoxic environment. When environmental conditions become favourable PAHs will be released to the overlying water as a long-term source and pose potential threat to water quality and aquatic ecosystem via bioaccumulation in food chains. Faced with these problems adsorption processes are one of the alternatives for PAHs retention. The adsorption of hydrophobic organic contaminants from aqueous phases generally increases with decreasing solubility of the compound and increasing organic carbon content of the aquifer solids. Natural materials with high organic carbon content such as coals or bituminous shales cause significant retardation of organic contaminants from groundwater. Such materials with high sorption capacities have been postulated and used for passive removal of hydrophobic contaminants in groundwater such as PAHs. Much more efficient is adsorption onto activated carbon, which is already a well-established technology for ex situ treatment of drinking water, polluted groundwater or waste water. One major advantages lies in the fact that the persistent compounds are removed from the ground water rather then being converted to still potentially dangerous metabolites as those generated by oxidation or reductive steps. One of the biggest disadvantages of the adsorption processes is the need to dispose or regenerate the adsorbent. In the case of activated carbon, it needs thermal desorption of the sorbed pollutants and thermal activation of the adsorbent. One of the possibilities to overcome this

  10. Preparation and characterization of a novel adsorbent from Moringa oleifera leaf

    Science.gov (United States)

    Bello, Olugbenga Solomon; Adegoke, Kayode Adesina; Akinyunni, Opeyemi Omowumi

    2017-06-01

    A new and novel adsorbent was obtained by impregnation of Moringa oleifera leaf in H2SO4 and NaOH, respectively. Prepared adsorbents were characterized using elemental analysis, FT-IR, SEM, TGA and EDX analyses, respectively. The effects of operational parameters, such as pH, moisture content, ash content, porosity and iodine number on these adsorbents were investigated and compared with those of commercial activated carbon (CAC). EDX results of acid activated M. oleifera leaf have the highest percentage of carbon by weight (69.40 %) and (76.11 %) by atom, respectively. Proximate analysis showed that the fixed carbon content of acid activated M. oleifera leaf (69.14 ± 0.01) was the highest of all adsorbents studied. Conclusively, the present investigation shows that acid activated M. oleifera leaf is a good alternative adsorbent that could be used in lieu of CAC for recovery of dyes and heavy metal from aqueous solutions and other separation techniques.

  11. Bicarbonate Elution of Uranium from Amidoxime-Based Polymer Adsorbents for Sequestering Uranium from Seawater

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Horng-Bin [Department of Chemistry, University of Idaho, Moscow, Idaho 83844 USA; Wai, Chien M. [Department of Chemistry, University of Idaho, Moscow, Idaho 83844 USA; Kuo, Li-Jung [Pacific Northwest National Laboratory, Marine Sciences Laboratory, Sequim, Washington 98382 USA; Gill, Gary [Pacific Northwest National Laboratory, Marine Sciences Laboratory, Sequim, Washington 98382 USA; Tian, Guoxin [Lawrence Berkeley National Laboratory, Berkeley, California 94720 USA; Rao, Linfeng [Lawrence Berkeley National Laboratory, Berkeley, California 94720 USA; Das, Sadananda [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 USA; Mayes, Richard T. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 USA; Janke, Christopher J. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 USA

    2017-05-02

    Uranium adsorbed on amidoxime-based polyethylene fibers in simulated seawater can be quantitatively eluted using 3 M KHCO3 at 40°C. Thermodynamic calculations are in agreement with the experimental observation that at high bicarbonate concentrations (3 M) uranyl ions bound to amidoxime molecules are converted to uranyl tris-carbonato complex in the aqueous solution. The elution process is basically the reverse reaction of the uranium adsorption process which occurs at a very low bicarbonate concentration (~10-3 M) in seawater. In real seawater experiments, the bicarbonate elution is followed by a NaOH treatment to remove natural organic matter adsorbed on the polymer adsorbent. Using the sequential bicarbonate and NaOH elution, the adsorbent is reusable after rinsing with deionized water and the recycled adsorbent shows no loss of uranium loading capacity based on real seawater experiments.

  12. Competitive adsorption of a two-component gas on a deformable adsorbent

    International Nuclear Information System (INIS)

    Usenko, A S

    2014-01-01

    We investigate the competitive adsorption of a two-component gas on the surface of an adsorbent whose adsorption properties vary due to the adsorbent deformation. The essential difference of adsorption isotherms for a deformable adsorbent both from the classical Langmuir adsorption isotherms of a two-component gas and from the adsorption isotherms of a one-component gas is obtained, taking into account variations in the adsorption properties of the adsorbent in adsorption. We establish bistability and tristability of the system caused by variations in adsorption properties of the adsorbent in competitive adsorption of gas particles on it. We derive conditions under which adsorption isotherms of a binary gas mixture have two stable asymptotes. It is shown that the specific features of the behavior of the system under study can be described in terms of a potential of the known explicit form. (paper)

  13. Extraction of uranium from sea water by means of fibrous complex adsorbents

    International Nuclear Information System (INIS)

    Miyamatsu, Tokuhisa; Oguchi, Noboru; Kanchiku, Yoshihiko; Aoyagi, Takanobu

    1982-01-01

    Fibrous complex adsorbents for uranium extraction from sea water were prepared by introducing titanic acid or basic zinc carbonate as effective constituents into fibrous ion exchangers. A fibrous chelate type adsorbent was also tested. Among the adsorbents examined, the following ones demonstrated excellent properties for the recovery of uranium from sea water. a) A fibrous, weakly acidic cation exchanger was treated with titanyl sulfate in aqueous sulfuric acid solution, which was followed by neutralization to afford a fibrous adsorbent containing titanic acid (QC-1f(Ti)). The adsorption capacity for uranium in sea water was estimated by extrapolation to be 50μg-U/g-Ad or 1170 μg-U/g-Ti. b) A fibrous, strongly acidic cation exchanger was treated in a similar way to afford another type of fibrous adsorbent with titanic acid incorporated (QCS-Ti). The adsorption capacity was estimated by extrapolation to be 20-30 μg-U/g-Ad. (author)

  14. Numerical study of friction of flake and adsorbed monolayer on atomically clean substrate

    International Nuclear Information System (INIS)

    Matsukawa, Hiroshi; Haraguchi, Kazuhiro; Ozaki, Shinsuke

    2007-01-01

    Frictional behaviors of flake and adsorbed monolayer on substrate can be observed by Frictional force microscope and Quartz crystal microbalance experiments and are typical problems in nano-friction. Computer simulations had been played important roles in understanding those behaviors, but in most of them the driving direction coincides with one of the crystal axes of the substrate. Here we report our numerical results of direction dependence of friction of flake and adsorbed monolayer. We found a new kind of dynamical phase transition in which flake and adsorbed monlayer change their structure relative to the substrate and make incommensurae structure to reduce kinetic frictional force after certain transition time. When the driving velocity is decreased the transition time tends to diverge at certain critical velocity for the flake. For the adsorbed monlayer the transition time tends to diverge at certain critical magnitudes of the external force or the interaction strength between adsorbates when they are decreased

  15. Application of chitin and zeolite adsorbents for treatment of low level radioactive liquid wastes

    International Nuclear Information System (INIS)

    Moattar, F.; Hayeripour, S.

    2004-01-01

    Two types of shrimp chitin derivatives and two types of Iranian natural zeolite derivates were studied for adsorption and treatment of low-level radioactive liquid waste. Chitin with lowers than 10% and chitosan with higher than 90% deacetylation factor were selected as neutral organic adsorbents. Natural clinoptilolite of Firuzkooh area and Na from derivates of it were selected as natural inorganic adsorbents. The static and dynamic ion exchange experimental results show that the ad adsorption efficiency depend on particle size, Ph, adsorbent type, deacetylation factor ( in chitin adsorbents) and cation type. The best Cs adsorption occurred in Na from clinoptilolite. Nevertheless chitin derivatives, particularly chitosan, are more efficient than zeolite adsorbents for removing of radionuclides such as 137 Cs, 54 Mn, 90 Sr and 60 Co. Adsorption performance was discussed and compared with each other

  16. 13C NMR and XPS characterization of anion adsorbent with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse

    International Nuclear Information System (INIS)

    Cao, Wei; Wang, Zhenqian; Zeng, Qingling; Shen, Chunhua

    2016-01-01

    Highlights: • 13 C NMR and XPS were successfully used to characterize quaternary ammonium groups in the surface of crop straw based anion adsorbents. • The results obtained from different kinds of crop straw material clearly confirmed the presence of quaternary ammonium groups. • The composition of C-groups and N-groups also were determined by curving fitting of high-resolution XPS C1 and N1 spectra. - Abstract: Despite amino groups modified crop straw has been intensively studied as new and low-cost adsorbent for removal of anionic species from water, there is still a lack of clear characterization for amino groups, especially quaternary ammonium groups in the surface of crop straw. In this study, we used 13 C NMR and XPS technologies to characterize adsorbents with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse. 13 C NMR spectra clearly showed the presence of quaternary ammonium groups in lignocelluloses structure of modified crop straw. The increase of nitrogen observed in XPS survey spectra also indicated the existence of quaternary ammonium group in the surface of the adsorbents. The curve fitting of high-resolution XPS N1s and C1s spectra were conducted to probe the composition of nitrogen and carbon contained groups, respectively. The results showed the proportion of quaternary ammonium group significantly increased in the prepared adsorbent’s surface that was dominated by methyl/methylene, hydroxyl, quaternary ammonium, ether and carbonyl groups. This study proved that 13 C NMR and XPS could be successfully utilized for characterization of quaternary ammonium modified crop straw adsorbents.

  17. {sup 13}C NMR and XPS characterization of anion adsorbent with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Wei, E-mail: weicao@hqu.edu.cn; Wang, Zhenqian; Zeng, Qingling; Shen, Chunhua

    2016-12-15

    Highlights: • {sup 13}C NMR and XPS were successfully used to characterize quaternary ammonium groups in the surface of crop straw based anion adsorbents. • The results obtained from different kinds of crop straw material clearly confirmed the presence of quaternary ammonium groups. • The composition of C-groups and N-groups also were determined by curving fitting of high-resolution XPS C1 and N1 spectra. - Abstract: Despite amino groups modified crop straw has been intensively studied as new and low-cost adsorbent for removal of anionic species from water, there is still a lack of clear characterization for amino groups, especially quaternary ammonium groups in the surface of crop straw. In this study, we used {sup 13}C NMR and XPS technologies to characterize adsorbents with quaternary ammonium groups prepared from rice straw, corn stalk and sugarcane bagasse. {sup 13}C NMR spectra clearly showed the presence of quaternary ammonium groups in lignocelluloses structure of modified crop straw. The increase of nitrogen observed in XPS survey spectra also indicated the existence of quaternary ammonium group in the surface of the adsorbents. The curve fitting of high-resolution XPS N1s and C1s spectra were conducted to probe the composition of nitrogen and carbon contained groups, respectively. The results showed the proportion of quaternary ammonium group significantly increased in the prepared adsorbent’s surface that was dominated by methyl/methylene, hydroxyl, quaternary ammonium, ether and carbonyl groups. This study proved that {sup 13}C NMR and XPS could be successfully utilized for characterization of quaternary ammonium modified crop straw adsorbents.

  18. An innovative zinc oxide-coated zeolite adsorbent for removal of humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lingling, E-mail: lasier_wang@hotmail.com [College of Chemical Engineering and Materials, Quanzhou Normal University, Quanzhou 362000, Fujian (China); Environmental Engineering and Science Program, 705 Engineering Research Center, University of Cincinnati, Cincinnati, OH 45221-0012 (United States); Han, Changseok [ORISE Post-doctoral Fellow, The U.S. Environmental Protection Agency, ORD, NRMRL, STD, CPB, 26 W. Martin Luther King Jr. Drive, Cincinnati, OH 45268 (United States); Nadagouda, Mallikarjuna N. [The U.S. Environmental Protection Agency, ORD, NRMRL, WSWRD, WQMB, 26 W. Martin Luther King Jr. Drive, Cincinnati, OH 45268 (United States); Dionysiou, Dionysios D., E-mail: dionysios.d.dionysiou@uc.edu [Environmental Engineering and Science Program, 705 Engineering Research Center, University of Cincinnati, Cincinnati, OH 45221-0012 (United States); Nireas-International Water Research Centre, School of Engineering, University of Cyprus, PO Box 20537, 1678, Nicosia (Cyprus)

    2016-08-05

    Highlights: • An innovative adsorbent was successfully synthesized to remove humic acid. • The adsorbent possessed high adsorption capacity for humic acid. • The adsorption capacity remarkably increased after an acid modification. • The adsorption capacity was proportional to the amount of ZnO coated on zeolite. • Electrostatic interactions are a major factor at the first stage of the process. - Abstract: Zinc oxide (ZnO)-coated zeolite adsorbents were developed by both nitric acid modification and Zn(NO{sub 3}){sub 2}·6H{sub 2}O functionalization of zeolite 4A. The developed adsorbents were used for the removal of humic acid (HA) from aqueous solutions. The synthesized materials were characterized by porosimetry analysis, scanning electron microscopy, X-Ray diffraction analysis, and high resolution transmission electron microscopy. The maximum adsorption capacity of the adsorbents at 21 ± 1 °C was about 60 mgC g{sup −1}. The results showed that the positive charge density of ZnO-coated zeolite adsorbents was proportional to the amount of ZnO coated on zeolite and thus, ZnO-coated zeolite adsorbents exhibited a greater affinity for negatively charged ions. Furthermore, the adsorption capacity of ZnO-coated zeolite adsorbents increased markedly after acid modification. Adsorption experiments demonstrated ZnO-coated zeolite adsorbents possessed high adsorption capacity to remove HA from aqueous solutions mainly due to strong electrostatic interactions between negative functional groups of HA and the positive charges of ZnO-coated zeolite adsorbents.

  19. An innovative zinc oxide-coated zeolite adsorbent for removal of humic acid

    International Nuclear Information System (INIS)

    Wang, Lingling; Han, Changseok; Nadagouda, Mallikarjuna N.; Dionysiou, Dionysios D.

    2016-01-01

    Highlights: • An innovative adsorbent was successfully synthesized to remove humic acid. • The adsorbent possessed high adsorption capacity for humic acid. • The adsorption capacity remarkably increased after an acid modification. • The adsorption capacity was proportional to the amount of ZnO coated on zeolite. • Electrostatic interactions are a major factor at the first stage of the process. - Abstract: Zinc oxide (ZnO)-coated zeolite adsorbents were developed by both nitric acid modification and Zn(NO_3)_2·6H_2O functionalization of zeolite 4A. The developed adsorbents were used for the removal of humic acid (HA) from aqueous solutions. The synthesized materials were characterized by porosimetry analysis, scanning electron microscopy, X-Ray diffraction analysis, and high resolution transmission electron microscopy. The maximum adsorption capacity of the adsorbents at 21 ± 1 °C was about 60 mgC g"−"1. The results showed that the positive charge density of ZnO-coated zeolite adsorbents was proportional to the amount of ZnO coated on zeolite and thus, ZnO-coated zeolite adsorbents exhibited a greater affinity for negatively charged ions. Furthermore, the adsorption capacity of ZnO-coated zeolite adsorbents increased markedly after acid modification. Adsorption experiments demonstrated ZnO-coated zeolite adsorbents possessed high adsorption capacity to remove HA from aqueous solutions mainly due to strong electrostatic interactions between negative functional groups of HA and the positive charges of ZnO-coated zeolite adsorbents.

  20. Modification of H2O adsorbed Si(100)-(2 x 1) surface by photon and electron beam

    International Nuclear Information System (INIS)

    Moon, S.W.; Chung, S.M.; Hwang, C.C.; Ihm, K.W.; Kang, T.-H.; Chen, C.H.; Park, C.-Y.

    2004-01-01

    Full text: Oxidation of silicon has been the subject of intense scientific and technological interest due to the several uses of thin oxide films as insulating layers in microelectronic devices. The great strides have been made in understanding about the formation and thermal evolution of the Si/SiO 2 interface. In this presentation, we provide synchrotron radiation photoemission spectroscopy (SRPES) and photoemission electron microscope (PEEM) results, showing how a H 2 O adsorbed Si(100) surface evolves into an ultra-thin silicon oxide m when exposed to monochromatized synchrotron radiation and electron beam at room temperature. All SRPES, PEEM experiments have been performed at the beam line, 4B1, of Pohang Light Source (PLS) in Korea. Water dissociates into OH(a) and H(a) species upon adsorption on the Si(100)-(2 - 1) at room temperature. The bonding (b 2 ) and antibonding (a 1 ) OH orbital and the oxygen lone pair orbital (b 1 ) from the dissociated OH and H species has been identified in ultraviolet photoemission spectra (UPS). These structures gradually changed and a new silicon oxide peak appeared with the photon/E-beam irradiation. This indicates that the H 2 O adsorbed on Si surface transforms into a thin silicon oxide film by photon/E-beam irradiation. We have shown in our PEEM images that one can make micro-patterns on silicon surface by using the photon induced surface modification. The fabricated patterns can be clearly identified through the inverse contrast images between photon exposed region and unexposed one. The near edge x-ray absorption fine structure (NEXAFS) results revealed that the OH adsorbed Si surface transforms into a thin silicon oxide film by photon irradiation

  1. Dietary bioavailability of Cu adsorbed to colloidal hydrous ferric oxide

    Science.gov (United States)

    Cain, Daniel J.; Croteau, Marie-Noële; Fuller, Christopher C.

    2013-01-01

    The dietary bioavailability of copper (Cu) adsorbed to synthetic colloidal hydrous ferric oxide (HFO) was evaluated from the assimilation of 65Cu by two benthic grazers, a gastropod and a larval mayfly. HFO was synthesized, labeled with 65Cu to achieve a Cu/Fe ratio comparable to that determined in naturally formed HFO, and then aged. The labeled colloids were mixed with a food source (the diatom Nitzschia palea) to yield dietary 65Cu concentrations ranging from 211 to 2204 nmol/g (dry weight). Animals were pulse fed the contaminated diet and assimilation of 65Cu from HFO was determined following 1–3 days of depuration. Mass transfer of 65Cu from HFO to the diatom was less than 1%, indicating that HFO was the source of 65Cu to the grazers. Estimates of assimilation efficiency indicated that the majority of Cu ingested as HFO was assimilated (values >70%), implying that colloidal HFO potentially represents a source of dietary Cu to benthic grazers, especially where there is active formation and infiltration of these particles into benthic substrates.

  2. A DFT study of Cu nanoparticles adsorbed on defective graphene

    International Nuclear Information System (INIS)

    García-Rodríguez, D.E.; Mendoza-Huizar, L.H.; Díaz, C.

    2017-01-01

    Highlights: • Cu_n supported on graphene may be a promising electrode material for DBFC's cells. • Cu_n/graphene interaction is rather local and size independent. • Cu_1_3 anchors strongly to defects in graphene, while keeping its gas-phase properties. - Abstract: Metal nanoparticles adsorbed on graphene are systems of interest for processes relative to catalytic reactions and alternative energy production. Graphene decorated with Cu-nanoparticles, in particular, could be a good alternative material for electrodes in direct borohydride fuel cells. However our knowledge of this system is still very limited. Based on density functional theory, we have analyzed the interaction of Cu_n nanoparticles (n = 4, 5, 6, 7, 13) with pristine and defective-graphene. We have considered two types of defects, a single vacancy (SV), and an extended lineal structural defect (ELSD), formed by heptagon-pentagon pairs. Our analysis has revealed the covalent character of the Cu_n-graphene interaction for pristine- and ELSD-graphene, and a more ionic-like interaction for SV-graphene. Furthermore, our analysis shows that the interaction between the nanoparticles and the graphene is rather local, i.e., only the nanoparticle atoms close to the contact region are involved in the interaction, being the electronic contact region much higher for defective-graphene than for pristine-graphene. Thus, the higher the particle the lower its average electronic and structural distortion.

  3. Vapor pressure of plutonium carbide adsorbed on graphite

    International Nuclear Information System (INIS)

    Tallent, O.K.; Wichner, R.P.; Towns, R.L.; Godsey, T.T.

    1984-09-01

    An investigation was conducted to obtain data needed to make realistic estimates of plutonium contamination in the primary coolant system in High Temperature Gas-Cooled Reactors (HTGRs). The vapor pressure of plutonium over plutonium sesquicarbide (Pu 2 C 3 ) adsorbed on the surface of H-451 graphite was found to be defined by adsorption isotherms at test temperatures of 1000, 1200, and 1400 0 C. The vapor pressures at low concentrations of Pu 2 C 3 on the surface of the graphite were up to three orders of magnitude below that of pure Pu 2 C 3 at a given temperature. The heat of adsorption increases with decreasing Pu 2 C 3 surface coverage with the measured value at 0.05 μmol Pu 2 C 3 /m 2 being 107.9 kcal/mol. The Pu 2 C 3 concentration required for monolayer surface coverage on the graphite was found to be 3.27 μmol/m 2

  4. Efficiency of sepiolite in broilers diet as uranium adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Mitrovic, Branislava M.; Lazarevic-Macanovic, Mirjana; Krstic, Nikola [University of Belgrade, Department of Radiology and Radiation Hygiene, Faculty of Veterinary Medicine, Belgrade (Serbia); Jovanovic, Milijan [University of Belgrade, Department of Veterinary Pathology, Faculty of Veterinary Medicine, Belgrade (Serbia); Janackovic, Djordje [University of Belgrade, Faculty of Technology and Metallurgy, Belgrade (Serbia); Stojanovic, Mirjana [University of Belgrade, Institute for Technology of Nuclear and Other Mineral Row Materials, Belgrade (Serbia); Mirilovic, Milorad [University of Belgrade, Department of Economics and Statistics, Faculty of Veterinary Medicine, Belgrade (Serbia)

    2015-05-15

    The use of phosphate mineral products in animal nutrition, as a major source of phosphor and calcium, can lead to uranium entering the food chain. The aim of the present study was to determine the protective effect of natural sepiolite and sepiolite treated with acid for broilers after oral intake of uranium. The broilers were contaminated for 7 days with 25 mg/uranyl nitrate per day. Two different adsorbents (natural sepiolite and sepiolite treated with acid) were given via gastric tube immediately after the oral administration of uranium. Natural sepiolite reduced uranium distribution by 57 % in kidney, 80 % in liver, 42 % in brain, and 56 % in muscle. A lower protective effect was observed after the administration of sepiolite treated with acid, resulting in significant damage of intestinal villi in the form of shortening, fragmentation, and necrosis, and histopathological lesions on kidney in the form of edema and abruption of epithelial cells in tubules. When broilers received only sepiolite treated with acid (no uranyl nitrate), shortening of intestinal villi occurred. Kidney injuries were evident when uranium concentrations in kidney were 0.88 and 1.25 μg/g dry weight. It is concluded that adding of natural sepiolite to the diets of broilers can reduce uranium distribution in organs by significant amount without adverse side effects. (orig.)

  5. Contact isotopic- and contact ion-exchange between two adsorbents

    International Nuclear Information System (INIS)

    Bunzl, K.; Mohan, R.; Haimerl, M.

    1975-01-01

    The kinetics of contact ion exchange processes between an ion exchange membrane and resin ion exchange beads, stirred in pure water, was investigated. A general criterion was derived, which indicates whether diffusion of the ions between the intermingling electric double layers or the collision frequency between the two adsorbents is the rate dermining step. Since the latter process proved to be rate controlling under our experimental conditions, the corresponding rate equations were derived under various initial and boundary conditions. Experimentally, the kinetics of contact isotopic exchange of Cs + - and Na + -ions as well as of the reverse contact ion exchange process of Cs + -versus Na + -ions were investigated by using Na 22 and Cs 137 radioisotopes. The experiments reveal in quantitative accord with the theory that the rate of collision controlled contact ion exchange processes depends mainly on the 'exchange coefficient', the separation factor and the collision frequency. While the latter two quantities were determined independently by separate experiments, the 'exchange coefficient' was evaluated from a contact isotopic exchange experiment. (orig.) [de

  6. A DFT study of Cu nanoparticles adsorbed on defective graphene

    Energy Technology Data Exchange (ETDEWEB)

    García-Rodríguez, D.E. [Universidad Politécnica de Aguascalientes, Calle Paseo San Gerardo No. 297 Fracc. San Gerardo, 20342 Aguascalientes, Ags. (Mexico); Mendoza-Huizar, L.H. [Universidad Autónoma del Estado de Hidalgo, Área Académica de Química, Ciudad del Conocimiento. Carretera Pachuca-Tulancigo Km. 4.5 Mineral de la Reforma, 42186 Hidalgo (Mexico); Díaz, C., E-mail: cristina.diaz@uam.es [Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid (Spain); Institute for Advanced Research in Chemical Science (IAdChem), Universidad Autónoma de Madrid, 28049 Madrid (Spain)

    2017-08-01

    Highlights: • Cu{sub n} supported on graphene may be a promising electrode material for DBFC's cells. • Cu{sub n}/graphene interaction is rather local and size independent. • Cu{sub 13} anchors strongly to defects in graphene, while keeping its gas-phase properties. - Abstract: Metal nanoparticles adsorbed on graphene are systems of interest for processes relative to catalytic reactions and alternative energy production. Graphene decorated with Cu-nanoparticles, in particular, could be a good alternative material for electrodes in direct borohydride fuel cells. However our knowledge of this system is still very limited. Based on density functional theory, we have analyzed the interaction of Cu{sub n} nanoparticles (n = 4, 5, 6, 7, 13) with pristine and defective-graphene. We have considered two types of defects, a single vacancy (SV), and an extended lineal structural defect (ELSD), formed by heptagon-pentagon pairs. Our analysis has revealed the covalent character of the Cu{sub n}-graphene interaction for pristine- and ELSD-graphene, and a more ionic-like interaction for SV-graphene. Furthermore, our analysis shows that the interaction between the nanoparticles and the graphene is rather local, i.e., only the nanoparticle atoms close to the contact region are involved in the interaction, being the electronic contact region much higher for defective-graphene than for pristine-graphene. Thus, the higher the particle the lower its average electronic and structural distortion.

  7. Morin Flavonoid Adsorbed on Mesoporous Silica, a Novel Antioxidant Nanomaterial.

    Directory of Open Access Journals (Sweden)

    Francisco Arriagada

    Full Text Available Morin (2´,3, 4´,5,7-pentahydroxyflavone is a flavonoid with several beneficial health effects. However, its poor water solubility and it sensitivity to several environmental factors avoid its use in applications like pharmaceutical and cosmetic. In this work, we synthetized morin-modified mesoporous silica nanoparticles (AMSNPs-MOR as useful material to be used as potential nanoantioxidant. To achieve this, we characterized its adsorption kinetics, isotherm and the antioxidant capacity as hydroxyl radical (HO• scavenger and singlet oxygen (1O2 quencher. The experimental data could be well fitted with Langmuir, Freundlich and Temkin isotherm models, besides the pseudo-second order kinetics model. The total quenching rate constant obtained for singlet oxygen deactivation by AMSNPs-MOR was one order of magnitude lower than the morin rate constant reported previously in neat solvents and lipid membranes. The AMSNPs-MOR have good antioxidant properties by itself and exhibit a synergic effect with morin on the antioxidant property against hydroxyl radical. This effect, in the range of concentrations studied, was increased when the amount of morin adsorbed increased.

  8. Hollow fiber-based liquid-liquid-liquid micro-extraction with osmosis: II. Application to quantification of endogenous gibberellins in rice plant.

    Science.gov (United States)

    Wu, Qian; Wu, Dapeng; Duan, Chunfeng; Shen, Zheng; Guan, Yafeng

    2012-11-23

    The phenomenon and benefits of osmosis in hollow fiber-based liquid-liquid-liquid micro-extraction (HF-LLLME) were theoretically discussed in part I of this study. In this work, HF-LLLME with osmosis was coupled with high performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-triple quadrupole MS/MS) to analyze eight gibberellins (gibberellin A(1), gibberellin A(3), gibberellin A(4), gibberellin A(7), gibberellin A(8), gibberellin A(9), gibberellin A(19) and gibberellin A(20)) in rice plant samples. According to the theory of HF-LLLME with osmosis, single factor experiments, orthogonal design experiments and mass transfer simulation of extraction process were carried out to select the optimal conditions. Cyclohexanol - n-octanol (1:3, v/v) was selected as organic membrane. Donor phase of 12 mL was adjusted to pH 2 and 20% NaCl (w/v) was added. Acceptor phase with an initial volume of 20 μL was the solution of 0.12 mol L(-1) Na(2)CO(3)-NaHCO(3) buffer (pH 9). Temperature was chosen to be 30 °C and extraction time was selected to be 90 min. Under optimized conditions, this method provided good linearity (r, 0.99552-0.99991) and low limits of detection (0.0016-0.061 ng mL(-1)). Finally, this method was applied to the analysis of endogenous gibberellins from plant extract which was obtained with traditional solvent extraction of rice plant tissues, and the relative recoveries were from 62% to 166%. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Simultaneous determination of several phytohormones in natural coconut juice by hollow fiber-based liquid-liquid-liquid microextraction-high performance liquid chromatography.

    Science.gov (United States)

    Wu, Yunli; Hu, Bin

    2009-11-06

    A simple, selective, sensitive and inexpensive method of hollow fiber-based liquid-liquid-liquid microextraction (HF-LLLME) combined with high performance liquid chromatography (HPLC)-ultraviolet (UV) detection was developed for the determination of four acidic phytohormones (salicylic acid (SA), indole-3-acetic acid (IAA), (+/-) abscisic acid (ABA) and (+/-) jasmonic acid (JA)) in natural coconut juice. To the best of our knowledge, this is the first report on the use of liquid phase microextraction (LPME) as a sample pretreatment technique for the simultaneous analysis of several phytohormones. Using phenetole to fill the pores of hollow fiber as the organic phase, 0.1molL(-1) NaOH solution in the lumen of hollow fiber as the acceptor phase and 1molL(-1) HCl as the donor phase, a simultaneous preconcentration of four target phytohormones was realized. The acceptor phase was finally withdrawn into the microsyringe and directly injected into HPLC for the separation and quantification of the target phytohormones. The factors affecting the extraction efficiency of four phytohormones by HF-LLLME were optimized with orthogonal design experiment, and the data was analyzed by Statistical Product and Service Solutions (SPSS) software. Under the optimized conditions, the enrichment factors for SA, IAA, ABA and JA were 243, 215, 52 and 48, with the detection limits (S/N=3) of 4.6, 1.3, 0.9ngmL(-1) and 8.8 microg mL(-1), respectively. The relative standard deviations (RSDs, n=7) were 7.9, 4.9, 6.8% at 50ngmL(-1) level for SA, IAA, ABA and 8.4% at 500 microg mL(-1) for JA, respectively. To evaluate the accuracy of the method, the developed method was applied for the simultaneous analysis of several phytohormones in five natural coconut juice samples, and the recoveries for the spiked samples were in the range of 88.3-119.1%.

  10. Hollow fiber-based liquid phase microextraction combined with high-performance liquid chromatography for extraction and determination of some antidepressant drugs in biological fluids.

    Science.gov (United States)

    Esrafili, Ali; Yamini, Yadollah; Shariati, Shahab

    2007-12-05

    The applicability of hollow fiber-based liquid phase microextraction (HF-LPME) was evaluated for the extraction and preconcentration of three antidepressant drugs (amitriptyline, imipramine and sertraline) prior to their determination by HPLC-UV. The target drugs were extracted from 11.0 mL of aqueous solution with pH 12.0 (source phase) into an organic extracting solvent (n-dodecane) impregnated in the pores of a hollow fiber and finally back extracted into 24 microL of aqueous solution located inside the lumen of the hollow fiber and adjusted to pH 2.1 using 0.1M of H3PO4 (receiving phase). The extraction was performed due to pH gradient between the inside and outside of the hollow fiber membrane. In order to obtain high extraction efficiency, the parameters affecting the HF-LPME including pH of the source and receiving phases, the type of organic phase, ionic strength and volume of the source phase, stirring rate and extraction time were studied and optimized. Under the optimized conditions, enrichment factors up to 300 were achieved and the relative standard deviation (R.S.D.%) of the method was in the range of 2-12%. The calibration curves were obtained in the range of 5-500 microg L(-1) with reasonable linearity (R2>0.998) and the limits of detection (LODs) ranged between 0.5 and 0.7 microg L(-1) (based on S/N=3). Finally, the applicability of the proposed method was evaluated by extraction and determination of the drugs in urine, plasma and tap water samples. The results indicated that hollow fiber microextraction method has excellent clean-up and high-preconcentration factor and can be served as a simple and sensitive method for monitoring of antidepressant drugs in the biological samples.

  11. Biosorption of Cr(VI from AqueousSolution Using New Adsorbent: Equilibrium and Thermodynamic Study

    Directory of Open Access Journals (Sweden)

    Israa G. Zainal

    2010-01-01

    Full Text Available Biosorption is one such emerging technology which utilized naturally occurring waste materials to sequester heavy metals from polluted water. In the present study cinnamon was utilized for Cr(VI removal from aqueous solutions.It was found that a time of two hours was sufficient for sorption to attain equilibrium. The optimum pH was 2 for Cr(VI removal. Temprature has little influence on the biosorption process. The Cr(VI removal decreased with increase in temperature. The biosorption data was well fitted to Dubinin - Radushkevich (D-R, Freundlich and Tempkin adsorption isotherm models, although the correlation coefficient of Langmuir model was high but the calculated adsorption capacity did not agree with the experimental. The thermodynamic study reveals that the biosorption process is spontaneous and the spontaneity decreased with temperature increase and the process is exothermic accompanied by highly ordered adsorbate at the solid liquid interface. ΔH° values were negative and lie in the range of physical adsorption.

  12. Theory of Covalent Adsorbate Frontier Orbital Energies on Functionalized Light-Absorbing Semiconductor Surfaces.

    Science.gov (United States)

    Yu, Min; Doak, Peter; Tamblyn, Isaac; Neaton, Jeffrey B

    2013-05-16

    Functional hybrid interfaces between organic molecules and semiconductors are central to many emerging information and solar energy conversion technologies. Here we demonstrate a general, empirical parameter-free approach for computing and understanding frontier orbital energies - or redox levels - of a broad class of covalently bonded organic-semiconductor surfaces. We develop this framework in the context of specific density functional theory (DFT) and many-body perturbation theory calculations, within the GW approximation, of an exemplar interface, thiophene-functionalized silicon (111). Through detailed calculations taking into account structural and binding energetics of mixed-monolayers consisting of both covalently attached thiophene and hydrogen, chlorine, methyl, and other passivating groups, we quantify the impact of coverage, nonlocal polarization, and interface dipole effects on the alignment of the thiophene frontier orbital energies with the silicon band edges. For thiophene adsorbate frontier orbital energies, we observe significant corrections to standard DFT (∼1 eV), including large nonlocal electrostatic polarization effects (∼1.6 eV). Importantly, both results can be rationalized from knowledge of the electronic structure of the isolated thiophene molecule and silicon substrate systems. Silicon band edge energies are predicted to vary by more than 2.5 eV, while molecular orbital energies stay similar, with the different functional groups studied, suggesting the prospect of tuning energy alignment over a wide range for photoelectrochemistry and other applications.

  13. Selective cesium removal from radioactive liquid waste by crown ether immobilized new class conjugate adsorbent.

    Science.gov (United States)

    Awual, Md Rabiul; Yaita, Tsuyoshi; Taguchi, Tomitsugu; Shiwaku, Hideaki; Suzuki, Shinichi; Okamoto, Yoshihiro

    2014-08-15

    Conjugate materials can provide chemical functionality, enabling an assembly of the ligand complexation ability to metal ions that are important for applications, such as separation and removal devices. In this study, we developed ligand immobilized conjugate adsorbent for selective cesium (Cs) removal from wastewater. The adsorbent was synthesized by direct immobilization of dibenzo-24-crown-8 ether onto inorganic mesoporous silica. The effective parameters such as solution pH, contact time, initial Cs concentration and ionic strength of Na and K ion concentrations were evaluated and optimized systematically. This adsorbent was exhibited the high surface area-to-volume ratios and uniformly shaped pores in case cavities, and its active sites kept open functionality to taking up Cs. The obtained results revealed that adsorbent had higher selectivity toward Cs even in the presence of a high concentration of Na and K and this is probably due to the Cs-π interaction of the benzene ring. The proposed adsorbent was successfully applied for radioactive Cs removal to be used as the potential candidate in Fukushima nuclear wastewater treatment. The adsorbed Cs was eluted with suitable eluent and simultaneously regenerated into the initial form for the next removal operation after rinsing with water. The adsorbent retained functionality despite several cycles during sorption-elution-regeneration operations. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Experimental study on the basic characteristics of a novel silica-based CMPO adsorbent

    International Nuclear Information System (INIS)

    Wei, Yuezhou; Arai, Tsuyoshi; Zhang, Anyun; Hoshi, Harutaka; Koma, Yoshikazu; Watanabe, Masayuki

    2002-01-01

    In order to establish the extraction chromatography process for recovery of minor actinides from HLLW with a novel silica-based CMPO (octyl(phenyl)-N, N-diisobutylcarbamoylmethylphosphine oxide) adsorbent, some basic characteristics, such as dissolving behavior of CMPO from the adsorbent, thermal decomposition of the adsorbent and treatment method of organic wastes, were examined. It was found that the leakage of CMPO from the adsorbent in contact with an aqueous solution is the result of the solubility of CMPO in the solution. About 40-50 ppm of CMPO constantly leaked into the effluent from the adsorbent packed column using 0.01 M (M=mol/dm 3 ) HNO 3 as a mobile phase. The leakage of CMPO from the adsorbent could be effectively depressed with the utilization of the aqueous solution saturated by CMPO. TG-DTA thermal analysis results indicate that CMPO in the adsorbent decomposed at 20degC and the SDB-polymer at 290degC. The impregnated CMPO could be completely dissolved out from the support with acetone. Furthermore, the organic wastes such as CMPO, oxalic acid and DTPA those come from the elution procedure could be effectively decomposed with the Fenton reagent. (author)

  15. Waste Material Adsorbents for Zinc Removal from Wastewater: A Comprehensive Review

    Directory of Open Access Journals (Sweden)

    Haider M. Zwain

    2014-01-01

    Full Text Available This review examines a variety of adsorbents and discusses mechanisms, modification methods, recovery and regeneration, and commercial applications. A summary of available researches has been composed by a wide range of potentially low-cost modified adsorbents including activated carbon, natural source adsorbents (clay, bentonite, zeolite, etc., biosorbents (black gram husk, sugar-beet pectin gels, citrus peels, banana and orange peels, carrot residues, cassava waste, algae, algal, marine green macroalgae, etc., and byproduct adsorbents (sawdust, lignin, rice husk, rice husk ash, coal fly ash, etc.. From the literature survey, different adsorbents were compared in terms of Zn2+ adsorption capacity; also Zn2+ adsorption capacity was compared with other metals adsorption. Thus, some of the highest adsorption capacities reported for Zn2+ are 168 mg/g powdered waste sludge, 128.8 mg/g dried marine green macroalgae, 73.2 mg/g lignin, 55.82 mg/g cassava waste, and 52.91 mg/g bentonite. Furthermore, modification of adsorbents can improve adsorption capacity. Regeneration cost is important, but if consumption of virgin adsorbent is reduced, then multiple economic, industrial, and environmental benefits can be gained. Finally, the main drawback of the already published Zn2+ adsorption researches is that their use is still in the laboratory stage mostly without scale-up, pilot studies, or commercialization.

  16. Equilibrium and heat of adsorption of diethyl phthalate on heterogeneous adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, W.M.; Xu, Z.W.; Pan, B.C.; Hong, C.H.; Jia, K.; Jiang, P.J.; Zhang, Q.J.; Pan, B.J. [Nanjing University, Nanjing (China)

    2008-09-15

    Removal of phthalate esters from water has been of considerable concern recently. In the present study, the adsorptive removal performance of diethyl phthalate (DEP) from water was investigated with the aminated polystyrene resin (NDA-101) and oxidized polystyrene resin (NDA-702). In addition, the commercial homogeneous polystyrene resin (XAD-4) and acrylic ester resin (Amberlite XAD-7) as well as coal-based granular activated carbon (AC-750) were chosen for comparison. The corresponding equilibrium isotherms are well described by the Freundlich equation and the adsorption capacities for DEP followed the order NDA-702 > NDA-101 > AC-750 > XAD-4 > XAD-7. Analysis of adsorption mechanisms suggested that these adsorbents spontaneously adsorb DEP molecules driven mainly by enthalpy change, and the adsorption process was derived by multiple adsorbent-adsorbate interactions such as hydrogen bonding, {pi}-{pi} stacking, and micropore filling. The information related to the adsorbent surface heterogeneity and the adsorbate-adsorbate interaction was obtained by Do's model. All the results indicate that heterogeneous resins NDA-702 and NDA-101 have excellent potential as an adsorption material for the removal of DEP from the contaminated water.

  17. Synthesis of magnetic ordered mesoporous carbon (Fe-OMC) adsorbent and its evaluation for fuel desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Farzin Nejad, N., E-mail: Farzinnejadn@ripi.ir [Petroleum Refining Technology Development Division, Research Institute of Petroleum Industry, Tehran 14857-33111 (Iran, Islamic Republic of); Shams, E.; Amini, M.K. [Department of Chemistry, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of)

    2015-09-15

    In this work, magnetic ordered mesoporous carbon adsorbent was synthesized using soft templating method to adsorb sulfur from model oil (dibenzothiophene in n-hexane). Through this research, pluronic F-127, resorcinol-formaldehyde and hydrated iron nitrate were respectively used as soft template, carbon source and iron source. The adsorbent was characterized by X-ray diffraction, nitrogen adsorption–desorption isotherm and transmission electron microscopy. Nitrogen adsorption–desorption measurement revealed the high surface area (810 m{sup 2} g{sup −1}), maxima pore size of 3.3 nm and large pore volume (1.01 cm{sup 3} g{sup −1}) of the synthesized sample. The adsorbent showed a maximum adsorption capacity of 111 mg dibenzothiophene g{sup −1} of adsorbent. Sorption process was described by the pseudo-second-order rate equation and could be better fitted by the Freundlich model, showing the heterogeneous feature of the adsorption process. In addition, the adsorption capacity of regenerated adsorbent was 78.6% of the initial level, after five regeneration cycles. - Highlights: • Adsorptive desulfurization of model oil with magnetic ordered mesoporous carbon adsorbent, Fe-OMC, was studied. • Maximum adsorption capacity (q{sub max}) of Fe-OMC for DBT was found to be 111.1 mg g{sup −1}. • Freundlich isotherm best represents the equilibrium adsorption data. • Rate of DBT adsorption process onto Fe-OMC is controlled by at least two steps.

  18. Synthesis of magnetic ordered mesoporous carbon (Fe-OMC) adsorbent and its evaluation for fuel desulfurization

    International Nuclear Information System (INIS)

    Farzin Nejad, N.; Shams, E.; Amini, M.K.

    2015-01-01

    In this work, magnetic ordered mesoporous carbon adsorbent was synthesized using soft templating method to adsorb sulfur from model oil (dibenzothiophene in n-hexane). Through this research, pluronic F-127, resorcinol-formaldehyde and hydrated iron nitrate were respectively used as soft template, carbon source and iron source. The adsorbent was characterized by X-ray diffraction, nitrogen adsorption–desorption isotherm and transmission electron microscopy. Nitrogen adsorption–desorption measurement revealed the high surface area (810 m 2 g −1 ), maxima pore size of 3.3 nm and large pore volume (1.01 cm 3 g −1 ) of the synthesized sample. The adsorbent showed a maximum adsorption capacity of 111 mg dibenzothiophene g −1 of adsorbent. Sorption process was described by the pseudo-second-order rate equation and could be better fitted by the Freundlich model, showing the heterogeneous feature of the adsorption process. In addition, the adsorption capacity of regenerated adsorbent was 78.6% of the initial level, after five regeneration cycles. - Highlights: • Adsorptive desulfurization of model oil with magnetic ordered mesoporous carbon adsorbent, Fe-OMC, was studied. • Maximum adsorption capacity (q max ) of Fe-OMC for DBT was found to be 111.1 mg g −1 . • Freundlich isotherm best represents the equilibrium adsorption data. • Rate of DBT adsorption process onto Fe-OMC is controlled by at least two steps

  19. Adsorption characteristics of benzene on biosolid adsorbent and commercial activated carbons

    Energy Technology Data Exchange (ETDEWEB)

    Hung-Lung Chiang; Kuo-Hsiung Lin; Chih-Yu Chen; Ching-Guan Choa; Ching-Shyung Hwu; Nina Lai [China Medical University, Taichung (Taiwan). Department of Risk Management

    2006-05-15

    This study selected biosolids from a petrochemical wastewater treatment plant as the raw material. The sludge was immersed in 0.5-5 M of zinc chloride (ZnCl{sub 2}) solutions and pyrolyzed at different temperatures and times. Results indicated that the 1-M ZnCl{sub 2}-immersed biosolids pyrolyzed at 500{sup o}C for 30 min could be reused and were optimal biosolid adsorbents for benzene adsorption. Pore volume distribution analysis indicated that the mesopore contributed more than the macropore and micropore in the biosolid adsorbent. The benzene adsorption capacity of the biosolid adsorbent was 65 and 55% of the G206 (granular-activated carbon) and BPL (coal-based activated carbon; Calgon, Carbon Corp.) activated carbons, respectively. Data from the adsorption and desorption cycles indicated that the benzene adsorption capacity of the biosolid adsorbent was insignificantly reduced compared with the first-run capacity of the adsorbent; therefore, the biosolid adsorbent could be reused as a commercial adsorbent, although its production cost is high. 18 refs., 9 figs., 3 tabs.

  20. Performance of adsorbent-embedded heat exchangers using binder-coating method

    KAUST Repository

    Li, Ang

    2016-01-01

    The performance of adsorption (AD) chillers or desalination cycles is dictated by the rates of heat and mass transfer of adsorbate in adsorbent-packed beds. Conventional granular-adsorbent, packed in fin-tube heat exchangers, suffered from poor heat transfer in heating (desorption) or cooling (adsorption) processes of the batch-operated cycles, with undesirable performance parameters such as higher footprint of plants, low coefficient of performance (COP) of AD cycles and higher capital cost of the machines. The motivation of present work is to mitigate the heat and mass "bottlenecks" of fin-tube heat exchangers by using a powdered-adsorbent cum binder coated onto the fin surfaces of exchangers. Suitable adsorbent-binder pairs have been identified for the silica gel adsorbent with pore surface areas up to 680 m2/g and pore diameters less than 6 nm. The parent silica gel remains largely unaffected despite being pulverized into fine particles of 100 μm, and yet maintaining its water uptake characteristics. The paper presents an experimental study on the selection and testing processes to achieve high efficacy of adsorbent-binder coated exchangers. The test results indicate 3.4-4.6 folds improvement in heat transfer rates over the conventional granular-packed method, resulting a faster rate of water uptake by 1.5-2 times on the suitable silica gel type. © 2015 Elsevier Ltd. All rights reserved.

  1. Adsorption characteristics of benzene on biosolid adsorbent and commercial activated carbons.

    Science.gov (United States)

    Chiang, Hung-Lung; Lin, Kuo-Hsiung; Chen, Chih-Yu; Choa, Ching-Guan; Hwu, Ching-Shyung; Lai, Nina

    2006-05-01

    This study selected biosolids from a petrochemical waste-water treatment plant as the raw material. The sludge was immersed in 0.5-5 M of zinc chloride (ZnCl2) solutions and pyrolyzed at different temperatures and times. Results indicated that the 1-M ZnCl2-immersed biosolids pyrolyzed at 500 degrees C for 30 min could be reused and were optimal biosolid adsorbents for benzene adsorption. Pore volume distribution analysis indicated that the mesopore contributed more than the macropore and micropore in the biosolid adsorbent. The benzene adsorption capacity of the biosolid adsorbent was 65 and 55% of the G206 (granular-activated carbon) and BPL (coal-based activated carbon; Calgon, Carbon Corp.) activated carbons, respectively. Data from the adsorption and desorption cycles indicated that the benzene adsorption capacity of the biosolid adsorbent was insignificantly reduced compared with the first-run capacity of the adsorbent; therefore, the biosolid adsorbent could be reused as a commercial adsorbent, although its production cost is high.

  2. Treatment of a simulated textile wastewater in a sequencing batch reactor (SBR) with addition of a low-cost adsorbent.

    Science.gov (United States)

    Santos, Sílvia C R; Boaventura, Rui A R

    2015-06-30

    Color removal from textile wastewaters, at a low-cost and consistent technology, is even today a challenge. Simultaneous biological treatment and adsorption is a known alternative to the treatment of wastewaters containing biodegradable and non-biodegradable contaminants. The present work aims at evaluating the treatability of a simulated textile wastewater by simultaneously combining biological treatment and adsorption in a SBR (sequencing batch reactor), but using a low-cost adsorbent, instead of a commercial one. The selected adsorbent was a metal hydroxide sludge (WS) from an electroplating industry. Direct Blue 85 dye (DB) was used in the preparation of the synthetic wastewater. Firstly, adsorption kinetics and equilibrium were studied, in respect to many factors (temperature, pH, WS dosage and presence of salts and dyeing auxiliary chemicals in the aqueous media). At 25 °C and pH 4, 7 and 10, maximum DB adsorption capacities in aqueous solution were 600, 339 and 98.7 mg/g, respectively. These values are quite considerable, compared to other reported in literature, but proved to be significantly reduced by the presence of dyeing auxiliary chemicals in the wastewater. The simulated textile wastewater treatment in SBR led to BOD5 removals of 53-79%, but color removal was rather limited (10-18%). The performance was significantly enhanced by the addition of WS, with BOD5 removals above 91% and average color removals of 60-69%. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Infrared spectroscopic and voltammetric study of adsorbed CO on stepped surfaces of copper monocrystalline electrodes

    International Nuclear Information System (INIS)

    Koga, O.; Teruya, S.; Matsuda, K.; Minami, M.; Hoshi, N.; Hori, Y.

    2005-01-01

    Voltammetric and infrared (IR) spectroscopic measurements were carried out to study adsorbed CO on two series of copper single crystal electrodes n(111)-(111) and n(111)-(100) in 0.1M KH 2 PO 4 +0.1M K 2 HPO 4 at 0 o C. Reversible voltammetric waves were observed below -0.55V versus SHE for adsorption of CO which displaces preadsorbed phosphate anions. The electric charge of the redox waves is proportional to the step atom density for both single crystal series. This fact indicates that phosphate anions are specifically adsorbed on the step sites below -0.55V versus SHE. Voltammetric measurements indicated that (111) terrace of Cu is covered with adsorbed CO below -0.5V versus SHE. Nevertheless, no IR absorption band of adsorbed CO is detected from (111) terrace. Presence of adsorbed CO on (111) terrace is presumed which is not visible by the potential difference spectroscopy used in the present work. IR spectroscopic measurements showed that CO is reversibly adsorbed with an on-top manner on copper single crystal electrodes of n(111)-(111) and n(111)-(100) with approximately same wavenumber of C?O stretching vibration of 2070cm -1 . The IR band intensity is proportional to the step atom density. Thus CO is adsorbed on (111) or (100) steps on the single crystal surfaces. An analysis of the IR band intensity suggested that one CO molecule is adsorbed on every two or more Cu step atom of the monocrystalline surface. The spectroscopic data were compared with those reported for uhv system. The C-O stretching wavenumber of adsorbed CO in the electrode-electrolyte system is 30-40cm -1 lower than those in uhv system

  4. Fast Removal of Polybrominated Diphenyl Ethers from Aqueous Solutions by Using Low-Cost Adsorbents

    Directory of Open Access Journals (Sweden)

    Renin Chang

    2017-01-01

    Full Text Available 4-Dibromodiphenyl ether (BDE-3 and 4,4′-dibromodiphenyl ether (BDE-15 are two of the major polybrominated diphenyl ethers used as flame-retardant additives in computer main boards and in fireproof building materials. In this study, we evaluated the potential of three low-cost adsorbents, black tea, green tea, and coconut palm leaf powders, to adsorb BDE-3 and BDE-15 from aqueous solutions. The results showed that pressure steam washing of the adsorbents increased their capacities to adsorb BDE-3 and BDE-15. The maximum adsorption capacities of pressure steam–washed black tea, green tea, and coconut palm leaf powders were 21.85 mg·L−1, 14.56 mg·L−1 and 22.47 mg·L−1, respectively. The results also showed that the adsorption equilibrium (qe was achieved at 4 min. Moreover, 97.8% of BDE-3 and 98.5% of BDE-15 could be removed by adsorbents pretreated with pressure steam washing. The kinetic data fitted well with a pseudo-second-order equation. The adsorption rate constants (k2 of all pressure steam–washed adsorbents ranged from 8.16 × 10−3 to 6.61 × 10−2 g·(mg·L−1−1·s−1, and the amount adsorbed at qe by all pressure steam–washed adsorbents ranged from 4.21 to 4.78 mg·L−1. Green alga Chlorella vulgaris was used as the test organism and the median effective concentration values of BDE-3 and BDE-15 were 7.24 and 3.88 mg·L−1, respectively. After BDE-3 and BDE-15 were removed from the solution, their biotoxicities markedly decreased. These findings indicate that these low-cost adsorbents can be used to remove BDE-3 and BDE-15 from aqueous solutions and wastewater.

  5. Carbon/Attapulgite Composites as Recycled Palm Oil-Decoloring and Dye Adsorbents

    Directory of Open Access Journals (Sweden)

    Guangyan Tian

    2018-01-01

    Full Text Available Activated clay minerals have been widely used in the edible oil refining industry for decolorization of crude oil by adsorption, and so far many methods have been used to improve their decolorization efficiency. Herein, we successfully prepared a series of carbon/attapulgite (C/APT composite adsorbents by a one-step in-situ carbonization process with natural starch (St as the carbon source. It has been revealed that the adsorbent had better decolorization efficiency for crude palm oil than acid-activated APT. However, more than a million tons of decolorized waste is produced every year in the oil-refining industry, which was often treated as solid waste and has not yet been reutilized effectively. In order to explore a viable method to recycle and reuse the decolorant, the waste decolorant was further prepared into new C/APT adsorbents for the removal of dyes from wastewater, and then the dyes adsorbed on the adsorbent were used as the carbon sources to produce new C/APT adsorbents by a cyclic carbonization process. The results showed that the adsorbents prepared from the decolorized waste could remove more than 99.5% of the methylene blue (MB, methyl violet (MV, and malachite green (MG dyes from the simulated wastewater with the dye concentration of 200 mg/L, and the C/APT–Re adsorbent consecutively regenerated five times using the adsorbed dyes as a carbon source still exhibit good adsorption efficiency for dyes. As a whole, this process opens a new avenue to develop efficient decolorants of palm oil and achieves recyclable utilization of decolored waste.

  6. Poorly crystalline hydroxyapatite: A novel adsorbent for enhanced fulvic acid removal from aqueous solution

    Science.gov (United States)

    Wei, Wei; Yang, Lei; Zhong, Wenhui; Cui, Jing; Wei, Zhenggui

    2015-03-01

    In this study, poorly crystalline hydroxyapatite (HAP) was developed as an efficient adsorbent for the removal of fulvic acid (FA) from aqueous solution. Surface functionality, crystallinity, and morphology of the synthetic adsorbent were studied by Fourier-transformation infrared (FT-IR) spectroscopy, powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). The effects of various parameters such as crystallinity of adsorbent, contact time, adsorbent dosage, pH, initial adsorbate concentration, temperature, ionic strength and the presence of alkaline earth metal ions on FA adsorption were investigated. Results indicated that the nanosized HAP calcined at lower temperature was poorly crystalline (Xc = 0.23) and had better adsorption capacity for FA than those (Xc = 0.52, 0.86) calcined at higher temperature. FA removal was increased with increases of adsorbent dosage, temperature, ionic strength and the presence of alkali earth metal ions, but decreased as the pH increased. Kinetic studies showed that pseudo-second-order kinetic model better described the adsorption process. Equilibrium data were best described by Sips models, and the estimated maximum adsorption capacity of poorly crystalline HAP was 90.20 mg/g at 318 K, displaying higher efficiency for FA removal than previously reported adsorbents. FT-IR results revealed that FA adsorption over the adsorbent could be attributed to the surface complexation between the oxygen atom of functional groups of FA and calcium ions of HAP. Regeneration studies indicated that HAP could be recyclable for a long term. Findings of the present work highlight the potential for using poorly crystalline HAP nanoparticles as an effective and recyclable adsorbent for FA removal from aqueous solution.

  7. Evaluating of arsenic(V) removal from water by weak-base anion exchange adsorbents.

    Science.gov (United States)

    Awual, M Rabiul; Hossain, M Amran; Shenashen, M A; Yaita, Tsuyoshi; Suzuki, Shinichi; Jyo, Akinori

    2013-01-01

    Arsenic contamination of groundwater has been called the largest mass poisoning calamity in human history and creates severe health problems. The effective adsorbents are imperative in response to the widespread removal of toxic arsenic exposure through drinking water. Evaluation of arsenic(V) removal from water by weak-base anion exchange adsorbents was studied in this paper, aiming at the determination of the effects of pH, competing anions, and feed flow rates to improvement on remediation. Two types of weak-base adsorbents were used to evaluate arsenic(V) removal efficiency both in batch and column approaches. Anion selectivity was determined by both adsorbents in batch method as equilibrium As(V) adsorption capacities. Column studies were performed in fixed-bed experiments using both adsorbent packed columns, and kinetic performance was dependent on the feed flow rate and competing anions. The weak-base adsorbents clarified that these are selective to arsenic(V) over competition of chloride, nitrate, and sulfate anions. The solution pH played an important role in arsenic(V) removal, and a higher pH can cause lower adsorption capacities. A low concentration level of arsenic(V) was also removed by these adsorbents even at a high flow rate of 250-350 h(-1). Adsorbed arsenic(V) was quantitatively eluted with 1 M HCl acid and regenerated into hydrochloride form simultaneously for the next adsorption operation after rinsing with water. The weak-base anion exchange adsorbents are to be an effective means to remove arsenic(V) from drinking water. The fast adsorption rate and the excellent adsorption capacity in the neutral pH range will render this removal technique attractive in practical use in chemical industry.

  8. Technologies for the 21st century: carbon nano tubes as adsorbents of metals

    International Nuclear Information System (INIS)

    Alguacil, F. J.; Cerpa, A.; Lado, I.; Lopez, F. A.

    2014-01-01

    Nowadays and in the recent past when the word nano appeared in almost anything it attracted immediate attention and interest, this is why carbon nano tubes, since its discovery nearly twenty years ago, caught the interest of a wide scientific and industrial population to apply the somewhat amazing properties of these nano materials in a number of applications. Among them, the removal of toxic and sometimes profitable metals from aqueous streams appeared, due to its economical and social impact, as one of the targets for their uses. This paper reviews some recent advances (2009-2013 years) in the application of carbon nano tubes materials in the removal of a variety of metals from these aqueous streams. (Author)

  9. Technologies for the 21st century: carbon nanotubes as adsorbents of metals

    Directory of Open Access Journals (Sweden)

    Alguacil, Francisco José

    2014-09-01

    Full Text Available Nowadays and in the recent past when the word “nano” appeared in almost anything it attracted immediate attention and interest, this is why carbon nanotubes, since its discovery nearly twenty years ago, caught the interest of a wide scientific and industrial population to apply the somewhat amazing properties of these nanomaterials in a number of applications. Among them, the removal of toxic and sometimes profitable metals from aqueous streams appeared, due to its economical and social impact, as one of the targets for their uses. This paper reviews some recent advances (2009–2013 years in the application of carbon nanotubes materials in the removal of a variety of metals from these aqueous streams.Tanto en el pasado como hoy en día, cuando la palabra “nano” aparece en cualquier sitio inmediatamente suscita atención e interés; por eso y desde su descubrimiento hace cerca de veinte años, los nanotubos de carbono interesaron tanto a científicos como a industriales, que utilizaron las propiedades de estos nanomateriales en una serie de aplicaciones. Entre éstas, se incluye la eliminación de metales tóxicos, y otros con un cierto valor económico, de medios acuosos, problemática que además tiene unas implicaciones económicas y sociales importantes. Este trabajo revisa los avances más recientes (años 2009–2013 de la utilización de estos nanotubos de carbono en la eliminación de una serie de metales contenidos en distintos medios acuosos.

  10. Adsorption behavior of cation-exchange resin-mixed polyethersulfone-based fibrous adsorbents with bovine serum albumin

    NARCIS (Netherlands)

    Zhang, Y.; Zhang, Yuzhong; Borneman, Zandrie; Koops, G.H.; Wessling, Matthias

    2006-01-01

    The cation-exchange resin-mixed polyethersulfone (PES)-based fibrous adsorbents were developed to study their adsorption behavior with bovine serum albumin (BSA). A fibrous adsorbent with an open pore surface had much better adsorption behavior with a higher adsorbing rate. The adsorption capacity

  11. Numerical Study on the Contribution of Convective Mass Transfer Inside High-Porosity Adsorbents in the VOC Adsorption Process

    DEFF Research Database (Denmark)

    Zhang, Ge; He, Wenna; Fang, Lei

    2013-01-01

    The transfer mechanism of volatile organic compounds (VOCs) being trapped inside the various types of adsorbents is usually regarded as mere diffusion. This paper investigated the contribution of convective mass transfer inside the adsorbents used for VOC air-cleaning. The adsorbents are typically...

  12. One-of-A-Kind: A Microporous Metal-Organic Framework Capable of Adsorptive Separation of Linear, Mono- and Di-branched Alkane Isomers via Temperature- and Adsorbate-Dependent Molecular Sieving

    KAUST Repository

    Wang, Hao

    2018-03-29

    Separation of alkane isomers represents a crucial process in the petrochemical industry in order to achieve high octane rating of gasoline. Herein, we report the first example of complete separation of linear, monobranched and dibranched alkane isomers by a single adsorbent. A calcium-based robust microporous metal-organic framework, Ca(H2tcpb) (tcpb = 1,2,4,5-tetrakis(4-carboxyphenyl)-benzene) exhibits unique molecular exclusion behavior which enables full separation of binary or ternary mixtures of alkane isomers into pure form of each isomerate. The successful separation of monobranched and dibranched hexane isomers will not only lead to the production of higher quality gasoline with maximum possible octane numbers but also fill the gap in the current separation technology. Exploration of separation mechanism indicates that structural flexibility and adsorbate-dependent structure change of the porous framework plays a vital role for the observed temperature-dependent molecular sieving property of the adsorbent.

  13. Pyrolyzed feather fibers for adsorbent and high temperature applications

    Science.gov (United States)

    Senoz, Erman

    Chicken feather fibers (CFF) are problematic and costly for the poultry industry in terms of managing maintenance and disposal. Considering their great availability, low cost, and unique protein structure, CFF can be an environmentally friendly and bio-renewable candidate to replace petroleum products. CFF's low degradation and melting temperature render them useless at high temperatures. Pyrolysis methods were developed for CFF by using two temperature steps to convert them into high temperature resistant and adsorbent fibers while retaining their original physical appearance and affine dimensions. An intermolecular crosslinking mechanism in the first step of pyrolysis at 215 ºC for 24 h provided an intact fibrous structure with no subsequent melting. The evidence obtained from the thermal, bulk, and surface analysis techniques was indication of the simultaneous side chain degradation, polypeptide backbone scission, disulfide bond cleavage, and isopeptide crosslinking. The variation in the reaction kinetics of disulfide bond cleavage and isopeptide crosslinking played an important role in the melting transition. Consequently, long-lasting heat treatments below the melting point provided sufficient crosslinks in the protein matrix to keep the fibrous structure intact. Water-insoluble and crosslinked CFF reinforced the triglyceride-fatty acid based composites by providing a 15 fold increase in storage and tensile modulus at room temperature. These thermally stable fibers can be used instead of CFF in composites which may require high temperature compounding and molding processes. The second step of pyrolysis at 400--450 ºC for 1 h resulted in microporous fibers with a micropore volume of ˜0.18 cm3/g STP and with a narrower pore size distribution than commercial activated carbons through thermal degradation. Nearly all accessible pores in the microporous pyrolyzed chicken feather fibers (PCFF) had diameters less than 1 nm and therefore, showed a potential to be

  14. Supported polytertiary amines: highly efficient and selective SO2 adsorbents.

    Science.gov (United States)

    Tailor, Ritesh; Abboud, Mohamed; Sayari, Abdelhamid

    2014-01-01

    Tertiary amine containing poly(propyleneimine) second (G2) and third (G3) generation dendrimers as well as polyethyleneimine (PEI) were developed for the selective removal of SO2. N-Alkylation of primary and secondary amines into tertiary amines was confirmed by FTIR and NMR analysis. Such modified polyamines were impregnated on two nanoporous supports, namely, SBA-15PL silica with platelet morphology and ethanol-extracted pore-expanded MCM-41 (PME) composite. In the presence of 0.1% SO2/N2 at 23 °C, the uptake of modified PEI, G2, and G3 supported on SBA-15PL was 2.07, 2.35, and 1.71 mmol/g, respectively; corresponding to SO2/N ratios of 0.22, 0.4, and 0.3. Under the same conditions, the SO2 adsorption capacity of PME-supported modified PEI and G3 was significantly higher, reaching 4.68 and 4.34 mmol/g, corresponding to SO2/N ratios of 0.41 and 0.82, respectively. The working SO2 adsorption capacity decreased with increasing temperature, reflecting the exothermic nature of the process. The adsorption capacity of these materials was enhanced dramatically in the presence of humidity in the gas mixture. FTIR data before SO2 adsorption and after adsorption and regeneration did not indicate any change in the materials. Nonetheless, the SO2 working capacity decreased in consecutive adsorption/regeneration cycles due to evaporation of impregnated polyamines, rather than actual deactivation. FTIR and (13)C and (15)N CP-MAS NMR of fresh and SO2 adsorbed modified G3 on PME confirmed the formation of a complexation adduct.

  15. Removing arsenic from groundwater in Cambodia using high performance iron adsorbent.

    Science.gov (United States)

    Kang, Y; Takeda, R; Nada, A; Thavarith, L; Tang, S; Nuki, K; Sakurai, K

    2014-09-01

    In Cambodia, groundwater has been contaminated with arsenic, and purification of the water is an urgent issue. From 2010 to 2012, an international collaborative project between Japan and Cambodia for developing arsenic-removing technology from well water was conducted and supported by the foundation of New Energy and Industrial Technology Development Organization, Japan. Quality of well water was surveyed in Kandal, Prey Veng, and Kampong Cham Provinces, and a monitoring trial of the arsenic removal equipment using our patented amorphous iron (hydr)oxide adsorbent was performed. Of the 37 wells surveyed, arsenic concentration of 24 exceeded the Cambodian guideline value (50 μg L(-1)), and those of 27 exceeded the WHO guideline for drinking water (10 μg L(-1)). Levels of arsenic were extremely high in some wells (>1,000-6,000 μg L(-1)), suggesting that arsenic pollution of groundwater is serious in these areas. Based on the survey results, 16 arsenic removal equipments were installed in six schools, three temples, two health centers, four private houses, and one commune office. Over 10 months of monitoring, the average arsenic concentrations of the treated water were between 0 and 10 μg L(-1) at four locations, 10-50 μg L(-1) at eight locations, and >50 μg L(-1) at four locations. The arsenic removal rate ranged in 83.1-99.7%, with an average of 93.8%, indicating that the arsenic removal equipment greatly lower the risk of arsenic exposure to the residents. Results of the field trial showed that As concentration of the treated water could be reduced to condition. This is one of the succeeding As removal techniques that could reduce As concentration of water below the WHO guideline value for As in situ.

  16. Dimensionless groups for multidimensional heat and mass transfer in adsorbed natural gas storage

    Energy Technology Data Exchange (ETDEWEB)

    Sphaier, L.A. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica. Lab. de Mecanica Teorica e Aplicada], E-mail: lasphaier@mec.uff.br

    2010-07-01

    This paper provides a new methodology for analyzing heat and mass transfer in gas storage via adsorption. The foundation behind the proposed methodology comprises a set of physically meaningful dimensionless groups. A discussion regarding the development of such groups is herein presented, providing a fully normalized multidimensional formulation for describing the transport mechanisms involved in adsorbed gas storage. After such presentation, data from previous literature studies associated with the problem of adsorbed natural gas storage are employed for determining realistic values for the developed parameters. Then, a one-dimensional test-case problem is selected for illustrating the application of the dimensionless formulation for simulating the operation of adsorbed gas reservoirs. The test problem is focused on analyzing an adsorbed gas discharge operation. This problem is numerically solved, and the solution is verified against previously published literature data. The presented results demonstrate how a higher heat of sorption values lead to reduced discharge capacities. (author)

  17. Characterization of Activated Carbon from Coal and Its Application as Adsorbent on Mine Acid Water Treatment

    Directory of Open Access Journals (Sweden)

    Siti Hardianti

    2017-06-01

    Full Text Available Anthracite and Sub-bituminous as activated carbon raw material had been utilized especially in mining field as adsorbent of dangerous heavy metal compound resulted in mining activity. Carbon from coal was activated physically and chemically in various temperature and particle sizes. Characterization was carried out in order to determine the adsorbent specification produced hence can be used and applied accordingly. Proximate and ultimate analysis concluded anthracite has fixed carbon 88.91% while sub-bituminous 49.05%. NaOH was used in chemical activation while heated at 400-500°C whereas physical activation was conducted at 800-1000°C. Activated carbon has high activity in adsorbing indicated by high iodine number resulted from analysis. SEM-EDS result confirmed that activated carbon made from coal has the quality in accordance to SNI and can be used as adsorbent in acid water treatment.

  18. Single walled carbon nanotubes functionally adsorbed to biopolymers for use as chemical sensors

    Science.gov (United States)

    Johnson, Jr., Alan T.; Gelperin, Alan [Princeton, NJ; Staii, Cristian [Madison, WI

    2011-07-12

    Chemical field effect sensors comprising nanotube field effect devices having biopolymers such as single stranded DNA functionally adsorbed to the nanotubes are provided. Also included are arrays comprising the sensors and methods of using the devices to detect volatile compounds.

  19. Inorganic ion exchangers and adsorbents for chemical processing in the nuclear fuel cycle

    International Nuclear Information System (INIS)

    1985-07-01

    The application of inorganic ion exchangers and adsorbents to both waste treatment and the recovery of fission products and actinides were of primary concern at this meeting. The meeting covered the two major fields of fundamental studies and industrial applications

  20. Determination of adsorbed protein concentration in aluminum hydroxide suspensions by near-infrared transmittance Spectroscopy

    DEFF Research Database (Denmark)

    Lai, Xuxin; Zheng, Yiwu; Jacobsen, Susanne

    2008-01-01

    , using the partial least square regression (PLSR) method to construct a calibration model. The linear concentration range of adsorbed BSA is from 0 to 1.75 mg/mL by using 10 mm path length cuvettes. The influence of the sedimentation in suspension, different buffers, and different aluminum hydroxide......Analysis of aluminum hydroxide based vaccines is difficult after antigen adsorption. Adsorbed protein is often assessed by measuring residual unadsorbed protein for quality control. A new method for the direct determination of adsorbed protein concentration in suspension using near-infrared (NIR......) transmittance spectroscopy is proposed here. A simple adsorption system using albumin from bovine serum (BSA) and aluminum hydroxide as a model system is employed. The results show that the NIR absorbance at 700-1300 nm is correlated to the adsorbed BSA concentration, measured by the ultraviolet (UV) method...

  1. Magnetic susceptibility of oxygen adsorbed on the surface of spherical and fibrous activated carbon.

    Directory of Open Access Journals (Sweden)

    Kiyoshi Kawamura

    2009-02-01

    Full Text Available The magnetic susceptibilities of oxygen adsorbed on the surface of bead-shaped activated carbon and activated carbon fibers were evaluated as a function of temperature between 4.2 K and 300 K, and found to exhibit a sharp peak at around 50 K. This implies that the adsorbed oxygen molecules form an antiferromagnetic state. The relation between the susceptibility and the adsorbed mass suggest that the thickness of the adsorbed oxygen is thin enough to consider a two-dimensional structure for bead–shaped activated carbon and carbon fibers across the fiber axis but thick enough to regard it as three-dimensional along the fiber axis. The result is discussed with reference to the study on one-dimensional oxygen array.

  2. Separation of Co(II) from dilute aqueous solutions by precipitate and adsorbing colloid flotation

    International Nuclear Information System (INIS)

    Aziz, M.; Benyamin, K.; Shakir, K.; Atomic Energy Establishment, Cairo

    1993-01-01

    Ion, precipitate and adsorbing colloid flotation of cobalt(II) have been investigated at different pH values, using N-dodecylpyridinium chloride (DPCl). A strong cationic surfactant, and sodium lauryl sulfate (NaLS), a strong anionic surfactant, as collectors. In case of adsorbing colloid flotation, hydrous manganese dioxide was used as an adsorbent. The precipitate flotation curves experimentally obtained with the two tested collectors were compared with the corresponding theoretical one calculated from the data published for Co(II) hydrolysis. The effects of the collector concentration, ageing of the water-MnO 2 -Co(II) system, bubbling time period, cobalt(II) concentration and foreign salts on the percent removal of Co(II) by adsorbing colloid flotation using DPCl as collector were determined. Removals approaching 100% could be achieved under the optimum conditions. (author) 44 refs.; 6 figs

  3. Heating and cooling system for an on-board gas adsorbent storage vessel

    Science.gov (United States)

    Tamburello, David A.; Anton, Donald L.; Hardy, Bruce J.; Corgnale, Claudio

    2017-06-20

    In one aspect, a system for controlling the temperature within a gas adsorbent storage vessel of a vehicle may include an air conditioning system forming a continuous flow loop of heat exchange fluid that is cycled between a heated flow and a cooled flow. The system may also include at least one fluid by-pass line extending at least partially within the gas adsorbent storage vessel. The fluid by-pass line(s) may be configured to receive a by-pass flow including at least a portion of the heated flow or the cooled flow of the heat exchange fluid at one or more input locations and expel the by-pass flow back into the continuous flow loop at one or more output locations, wherein the by-pass flow is directed through the gas adsorbent storage vessel via the by-pass line(s) so as to adjust an internal temperature within the gas adsorbent storage vessel.

  4. ε-Polylysine-based thermo-responsive adsorbents for immunoglobulin adsorption-desorption under mild conditions.

    Science.gov (United States)

    Maruyama, Masashi; Shibuya, Keisuke

    2017-08-22

    Thermo-responsive adsorbents for immunoglobulin G (IgG) employing ε-polylysine (EPL) as a polymer backbone were developed. The introduction of mercaptoethylpyridine (MEP) as an IgG-binding ligand and hydrophobization of side chains afforded thermo-responsive IgG adsorbents, whose thermo-responsive IgG desorption ratio was up to 88% (EPL/MEP derivative 3m). The changes in surface densities of active MEP groups, which are caused by thermal conformational changes of the adsorbents, play key roles for IgG desorption. Although a trade-off of IgG adsorption capacity and IgG desorption ratio was observed, the present study offers a novel molecular design for thermo-responsive adsorbents with high synthetic accessibility and potentially low toxicity.

  5. Rigorous Mathematical Modeling of an Adsorption System With Electrothermal Regeneration of the Used Adsorbent

    National Research Council Canada - National Science Library

    Petkovska, Menka; Antov-Bozalo, Danijela; Markovic, Ana

    2005-01-01

    The general objective of the project is fundamental mathematical modeling of a complex TSA system with electrothermal desorption step, with adsorbers assembled of one or more activated carbon fiber clot (ACFC...

  6. Dynamics of CO 2 Adsorption on Amine Adsorbents. 1. Impact of Heat Effects

    KAUST Repository

    Bollini, Praveen; Brunelli, Nicholas A.; Didas, Stephanie A.; Jones, Christopher W.

    2012-01-01

    in this study. The results help establish that under certain experimental conditions, heat effects in amine adsorbent packed beds have a negligible effect on CO2 breakthrough, and simple isothermal models can be used to accurately assess adsorption kinetics

  7. Exfoliated polypyrrole-organically modified montmorillonite clay nanocomposite as a potential adsorbent for Cr (VI) removal

    CSIR Research Space (South Africa)

    Setshedi, KZ

    2013-01-01

    Full Text Available Exfoliated polypyrrole-organically modified montmorillonite clay nanocomposite (PPy OMMT NC), was prepared as a potential adsorbent, via in situ polymerization of pyrrole monomer for adsorption of toxic Cr(VI) from aqueous solution. The WAXD...

  8. Adsorbate-induced lifting of substrate relaxation is a general mechanism governing titania surface chemistry.

    Science.gov (United States)

    Silber, David; Kowalski, Piotr M; Traeger, Franziska; Buchholz, Maria; Bebensee, Fabian; Meyer, Bernd; Wöll, Christof

    2016-09-30

    Under ambient conditions, almost all metals are coated by an oxide. These coatings, the result of a chemical reaction, are not passive. Many of them bind, activate and modify adsorbed molecules, processes that are exploited, for example, in heterogeneous catalysis and photochemistry. Here we report an effect of general importance that governs the bonding, structure formation and dissociation of molecules on oxidic substrates. For a specific example, methanol adsorbed on the rutile TiO 2 (110) single crystal surface, we demonstrate by using a combination of experimental and theoretical techniques that strongly bonding adsorbates can lift surface relaxations beyond their adsorption site, which leads to a significant substrate-mediated interaction between adsorbates. The result is a complex superstructure consisting of pairs of methanol molecules and unoccupied adsorption sites. Infrared spectroscopy reveals that the paired methanol molecules remain intact and do not deprotonate on the defect-free terraces of the rutile TiO 2 (110) surface.

  9. Evaluation of optimal silver amount for the removal of methyl iodide on silver-impregnated adsorbents

    International Nuclear Information System (INIS)

    Park, G.I.; Cho, I.H.; Kim, J.H.; Oh, W.Z.

    2001-01-01

    The adsorption characteristics of methyl iodide generated from the simulated off-gas stream on various adsorbents such as silver-impregnated zeolite (AgX), zeocarbon and activated carbon were investigated. An extensive evaluation was made on the optimal silver impregnation amount for the removal of methyl iodide at temperatures up to 300 deg. C. The degree of adsorption efficiency of methyl iodide on silver-impregnated adsorbent is strongly dependent on impregnation amount and process temperature. A quantitative comparison of adsorption efficiencies on three adsorbents in a fixed bed was investigated. The influence of temperature, methyl iodide concentration and silver impregnation amount on the adsorption efficiency is closely related to the pore characteristics of adsorbents. It shows that the effective impregnation ratio was about 10wt%, based on the degree of silver utilization for the removal of methyl iodide. The practical applicability of silver-impregnated zeolite for the removal of radioiodine generated from the DUPIC process was consequently proposed. (author)

  10. Influence of adsorbed carbon dioxide on hydrogen electrosorption in palladium-platinum-rhodium alloys

    International Nuclear Information System (INIS)

    Lukaszewski, M.; Grden, M.; Czerwinski, A.

    2004-01-01

    Carbon dioxide electroreduction was applied to examine the processes of hydrogen electrosorption (adsorption, absorption and desorption) by thin electrodeposits of Pd-Pt-Rh alloys under conditions of cyclic voltammetric (CV) experiments. Due to different adsorption characteristics towards the adsorption product of the electroreduction of CO 2 (reduced CO 2 ) exhibited by the alloy components hydrogen adsorption and hydrogen absorption signals can be distinguished on CV curves. Reduced CO 2 causes partial blocking of hydrogen adsorbed on surface Pt and Rh atoms, without any significant effect on hydrogen absorption into alloy. It reflects the fact that adsorbed hydrogen bonded to Pd atoms does not participate in CO 2 reduction, while hydrogen adsorbed on Pt and Rh surface sites is inactive in the absorption reaction. In contrast, CO is adsorbed on all alloy components and causes a marked inhibition of hydrogen sorption (both adsorption and absorption)/desorption reactions

  11. Removal of radium from aqueous solutions using adsorbent produced from coconut coir pith

    International Nuclear Information System (INIS)

    Zalina Laili; Muhamat Omar; Mohd Zaidi Ibrahim; Esther Phillip; Mohd Abdul Wahab Yusof; Hassan, A.

    2008-08-01

    A study was conducted to evaluate the potential use of the coconut coir pith as an adsorbent for the removal of radium from aqueous solutions. Experiments to establish adsorptions as a function of pH and contact time were carried out. The results showed that radium adsorption are dependent upon pH and contact time of coconut coir pith with aqueous solutions. 70-80% of radium were adsorbed in the neutral to alkaline pH range. The amount of radium adsorbed also increased with contact time, reaching an optimum after 250 min. Thus, it can be concluded that the coconut coir pith has the potential to be used as an adsorbent in radium removal from aqueous solutions. (Author)

  12. Structures of adsorbed CO on atomically smooth and on stepped sngle crystal surfaces

    International Nuclear Information System (INIS)

    Madey, T.E.; Houston, J.E.

    1980-01-01

    The structures of molecular CO adsorbed on atomically smooth surfaces and on surfaces containing monatomic steps have been studied using the electron stimulated desorption ion angular distribution (ESDIAD) method. For CO adsorbed on the close packed Ru(001) and W(110) surfaces, the dominant bonding mode is via the carbon atom, with the CO molecular axis perpendicular to the plane of the surface. For CO on atomicaly rough Pd(210), and for CO adsorbed at step sites on four different surfaces vicinal to W(110), the axis of the molecule is tilted or inclined away from the normal to the surface. The ESDIAD method, in which ion desorption angles are related to surface bond angles, provides a direct determination of the structures of adsorbed molecules and molecular complexes on surfaces

  13. Prussian blue caged in spongiform adsorbents using diatomite and carbon nanotubes for elimination of cesium.

    Science.gov (United States)

    Hu, Baiyang; Fugetsu, Bunshi; Yu, Hongwen; Abe, Yoshiteru

    2012-05-30

    We developed a spongiform adsorbent that contains Prussian blue, which showed a high capacity for eliminating cesium. An in situ synthesizing approach was used to synthesize Prussian blue inside diatomite cavities. Highly dispersed carbon nanotubes (CNTs) were used to form CNT networks that coated the diatomite to seal in the Prussian blue particles. These ternary (CNT/diatomite/Prussian-blue) composites were mixed with polyurethane (PU) prepolymers to produce a quaternary (PU/CNT/diatomite/Prussian-blue), spongiform adsorbent with an in situ foaming procedure. Prussian blue was permanently immobilized in the cell walls of the spongiform matrix and preferentially adsorbed cesium with a theoretical capacity of 167 mg/g cesium. Cesium was absorbed primarily by an ion-exchange mechanism, and the absorption was accomplished by self-uptake of radioactive water by the quaternary spongiform adsorbent. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Electronic properties of adsorbates and clean surfaces of metals and semiconductors

    International Nuclear Information System (INIS)

    Lecante, J.

    1980-01-01

    This paper surveys recent progress in experimental studies on electronic properties of adsorbates and clean metal surfaces. Electron spectroscopy and particularly angle resolved photoelectron spectroscopy appears to be a very powerful tool to get informations on electronic levels of adsorbates or clean surfaces. Moreover this technique may also give informations about the atomic geometry of the surface. Experimental investigation about surface plasmons, surface states, core level shifts are presented for clean surfaces. As examples of adsorbate covered surfaces two typical cases are chosen: two dimensional band structure and oriented molecules. Finally the photoelectron diffraction may be used for surface structure determination either in the case of an adsorbate or a clean metal surface [fr

  15. Comparison of thermal behavior of natural and hot-washed sisal fibers based on their main components: Cellulose, xylan and lignin. TG-FTIR analysis of volatile products

    Energy Technology Data Exchange (ETDEWEB)

    Benítez-Guerrero, Mónica, E-mail: monica_benitez_guerrero@yahoo.es [Departamento de Ingeniería Civil, Materiales y Fabricación, Universidad de Málaga, Escuela de Ingenierías, C/ Dr. Ortiz Ramos s/n, Campus Teatinos, 29071 Málaga (Spain); López-Beceiro, Jorge [Departamento de Ingeniería Industrial II, Escola Politécnica Superior, Universidade da Coruña, Avda. Mendizábal, 15403 Ferrol (Spain); Sánchez-Jiménez, Pedro E. [Instituto de Ciencia de Materiales de Sevilla, CSIC-Universidad de Sevilla, C/ Américo Vespucio 49, 41092 Sevilla (Spain); Pascual-Cosp, José [Departamento de Ingeniería Civil, Materiales y Fabricación, Universidad de Málaga, Escuela de Ingenierías, C/ Dr. Ortiz Ramos s/n, Campus Teatinos, 29071 Málaga (Spain)

    2014-04-01

    Highlights: • Thermal decomposition of sisal fibers has been discussed. • Decompositions of lignocellulosic components and sisal are compared by TXRD and TG-FTIR. • Hot washing reduces the temperature range in which sisal decomposition occurs. • Sisal cellulose decomposition goes by an alternative route to levoglucosan generation. - Abstract: This paper presents in a comprehensive way the thermal behavior of natural and hot-washed sisal fibers, based on the fundamental components of lignocellulosic materials: cellulose, xylan and lignin. The research highlights the influence exerted on the thermal stability of sisal fibers by other constituents such as non-cellulosic polysaccharides (NCP) and mineral matter. Thermal changes were investigated by thermal X-ray diffraction (TXRD), analyzing the crystallinity index (%Ic) of cellulosic samples, and by simultaneous thermogravimetric and differential thermal analysis coupled with Fourier-transformed infrared spectrometry (TG/DTA-FTIR), which allowed to examine the evolution of the main volatile compounds evolved during the degradation under inert and oxidizing atmospheres. The work demonstrates the potential of this technique to elucidate different steps during the thermal decomposition of sisal, providing extensible results to other lignocellulosic fibers, through the analysis of the evolution of CO{sub 2}, CO, H{sub 2}O, CH{sub 4}, acetic acid, formic acid, methanol, formaldehyde and 2-butanone, and comparing it with the volatile products from pyrolysis of the biomass components. The hydroxyacetaldehyde detected during pyrolysis of sisal is indicative of an alternative route to that of levoglucosan, generated during cellulose pyrolysis. Hot-washing at 75 °C mostly extracts non-cellulosic components of low decomposition temperature, and reduces the range of temperature in which sisal decomposition occurs, causing a retard in the pyrolysis stage and increasing Tb{sub NCP} and Tb{sub CEL}, temperatures at the

  16. MODIFICATION OF KELUD VOLCANIC ASH 2014 AS SELECTIVE ADSORBENT MATERIAL FOR COPPER(II METAL ION

    Directory of Open Access Journals (Sweden)

    Susila Kristianingrum

    2017-01-01

      This research aims to prepare an adsorbent from Kelud volcanic ash for better Cu(II adsorption efficiency than Kiesel gel 60G E'Merck. Adsorbent synthesis was done by dissolving 6 grams of volcanic ash activated 700oC 4 hours and washed with HCl 0.1 M into 200 ml of 3M sodium hydroxide with stirring and heating of 100 °C for 1 hour. The filtrate sodium silicate was then neutralized using sulfuric acid. The mixture was allowed to stand for 24 hours then filtered and washed with aquaDM, then dried and crushed. The procedure is repeated for nitric acid, acetic acid and formic acid with a contact time of 24 hours. The products were then characterized using FTIR and XRD, subsequently determined acidity, moisture content, and tested for its adsorption of the ion Cu (II with AAS. The results showed that the type of acid that produced highest rendemen is AK-H2SO4-3M ie 36.93%, acidity of the adsorbent silica gel synthesized similar to Kiesel gel 60G E'Merck ie adsorbent AK-CH3COOH-3M and the water content of the silica gel adsorbent synthesized similar to Kiesel gel 60G E'Merck ie adsorbent AK-H2SO4-2 M. The character of the functional groups of silica gel synthesized all have similarities with Kiesel gel 60G E'Merck as a comparison. Qualitative analysis by XRD for all modified adsorbent showed a dominant peak of SiO2 except adsorbent AK-H2SO4 amorphous and chemical bonds with FTIR indicates that it has formed a bond of Si-O-Si and Si-OH. The optimum adsorption efficiency of the metal ions Cu(II obtained from AK-H2SO4-5M adsorbent that is equal to 93.2617% and the optimum adsorption capacity of the Cu(II metal ions was obtained from the adsorbent AK-CH3COOH-3M is equal to 2.4919 mg/ g.   Keywords: adsorbents, silica gel, adsorption, kelud volcanic ash

  17. An investigation of the sorption/desorption of organics from natural waters by solid adsorbents and anion exchangers

    International Nuclear Information System (INIS)

    Larin, B.M.; Sedlov, A.S.

    2006-01-01

    The results of laboratory and operational tests at thermal and nuclear power stations on anion exchangers and solid adsorbents of makeup water treatment plants with regard to the sorption/desorption of organic substances in natural water and condensate are presented. The resins Amberlite trademark IRA-67, IRA-900, IRA-958Cl, Purolite registered 2 A-500P, Dowex TM3 Marathon, and others were tested. Retention of up to 60-80% of the ''organic'' material on the anion exchangers and organic absorbers installed at different places in the technological scheme of the water processing unit was attained. The possibility of a partial ''poisoning'' of the resins and the degradation of the working characteristics over the first year of operation are discussed. (orig.)

  18. The design of a modular pilot plant based on the adsorber loop concept

    International Nuclear Information System (INIS)

    Koske, P.H.; Ohlrogge, K.

    1984-01-01

    The main design criteria for a pilot plant producing about 100 t uranium per year from seawater are discussed. The application of the ''adsorber loop concept'' for the contact between seawater and the adsorber granulate enables the employment of high seawater velocities. The seawater flow is accomplished by active pumping and the plant is supposed to be operating far from shores. Besides some informations on the theoretical background the essential engineering considerations are presented. (orig.) [de

  19. Influence of solvent on the infared spectrum of carbon monoxide adsorbed on platinum electrodes

    OpenAIRE

    Feltovich, Susanne D.

    1993-01-01

    The behavior of adsorbed carbon monoxide on platinum was studied using potential difference infrared spectroscopy. Three solvents and three electrolytes were chosen, and data gathered at both high and low adsorbate coverages. The rate of change of IR peak position with applied potential, the Stark tuning rate, was used as an indicator of the local electric field strength at the interface. It was determined that neither solvated cation size nor bulk dielectric constant accoun...

  20. Application of new mycotoxin adsorbent-bentonite clay “Askangel” in poultry feed

    OpenAIRE

    A. Chkuaseli; M. Khutsishvili-Maisuradze; A. Chagelishvili; K. Natsvaladze; T. Lashkarashvili; G. Chagelishvili; N. Maisuradze

    2016-01-01

    In order to mitigate the negative effect of mycotoxins the major researches have been conducted to obtain the mycotoxins adsorbent in recent years. As for the adsorbents, they are substances of a firm or liquid form, on which surface the mycotoxins are absorbed and prevent transition of mycotoxins from the intestines walls in to blood system. The bentonite clay obtained in western region of Georgia (Guria, Ozurgeti) is characterized with a broad range of ion exchange, high colloidal, enriched...

  1. Structure of solid surfaces and of adsorbates by low-energy electron diffraction

    International Nuclear Information System (INIS)

    Somorjai, G.A.

    1977-01-01

    LEED theory has developed to the point where the diffraction beam intensities can be computed using the locations of the surface atoms as the only adjustable parameters. The position of atoms in many clean monatomic solid surfaces and the surface structures of ordered monolayers of adsorbed atoms have been determined this way. Surface crystallography studies are now extended to small hydrocarbon molecules that are adsorbed on metal surfaces. These studies are reviewed

  2. Metal Adsorbent Prepared from Poly(Methyl Acrylate)-Grafted Cassava Starch via Gamma Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Suwanmala, P; Hemvichian, K; Srinuttrakul, W [Nuclear Research and Development Group, Thailand Institute of Nuclear Technology, Bangkok (Thailand)

    2012-09-15

    Metal adsorbent containing hydroxamic acid groups was successfully synthesized by radiation-induced graft copolymerization of methyl acrylate (MA) onto cassava starch. The optimum conditions for grafting were studied in terms of % degree of grafting (Dg). Conversion of the ester groups present in poly(methyl acrylate)-grafted-cassava starch copolymer into hydroxamic acid was carried out by treatment with hydroxylamine (HA) in the presence of alkaline solution. The maximum percentage conversion of the ester groups of the grafted copolymer, %Dg = 191 (7.63 mmol/g of MA), into the hydroxamic groups was 70% (5.35 mmol/g of MA) at the optimum conditions: in a mixture solution of 20% HA (w/v) and methanol solution (methanol:H{sub 2}O = 5:1) 300 mL, pH 13, reaction time 2 h, and 20 g of grafted copolymer. The adsorbent was characterized by FTIR, TGA, and DSC. The presence of electron donating groups in adsorbent containing hydroxamic acid groups gives the ability to form polycomplexes with metal ions. The ability of the adsorbent to adsorb various metals was investigated in order to evaluate the possibility of its use in metal adsorption. The adsorbent exhibited a remarkable % adsorption for Cd{sup 2+}, Al{sup 3+}, UO{sub 2} {sup 2+}, V{sup 5+} and Pb{sup 2+} at pH 3, 4, 5, 4, and 3, respectively. The adsorbent of 191%Dg had total adsorption capacities of 2.6, 1.46, 1.36, 1.15, and 1.6 mmol/g adsorbent for Cd{sup 2+}, Al{sup 3+}, UO{sub 2} {sup 2+}, V{sup 5+} and Pb{sup 2+}, respectively, in the batch mode adsorption. (author)

  3. Characterization of Activated Carbon from Coal and Its Application as Adsorbent on Mine Acid Water Treatment

    OpenAIRE

    Siti Hardianti; Susila Arita Rachman; Harminuke E.H.

    2017-01-01

    Anthracite and Sub-bituminous as activated carbon raw material had been utilized especially in mining field as adsorbent of dangerous heavy metal compound resulted in mining activity. Carbon from coal was activated physically and chemically in various temperature and particle sizes. Characterization was carried out in order to determine the adsorbent specification produced hence can be used and applied accordingly. Proximate and ultimate analysis concluded anthracite has fixed carbon 88.91% w...

  4. Presence of electrostatically adsorbed polysaccharides improves spray drying of liposomes.

    Science.gov (United States)

    Karadag, Ayse; Özçelik, Beraat; Sramek, Martin; Gibis, Monika; Kohlus, Reinhard; Weiss, Jochen

    2013-02-01

    functional components. However, maintaining their stability in aqueous dispersion represents a challenge for their commercialization. Spray drying may promise a solution to that problem. However, prior to this study spray drying of liposomes often led to the loss of structural integrity. Results of this study suggest that spray drying might be used to produce commercially feasible liposomal powders if proper combinations of adsorbing and nonadsorbing polymers are used in the liquid precursor system. © 2013 Institute of Food Technologists®

  5. Mineral Adsorbents for Removal of Metals in Urban Runoff

    Science.gov (United States)

    Bjorklund, Karin; Li, Loretta

    2014-05-01

    The aim of this research was to determine the capacity of four different soil minerals to adsorb metals frequently detected in urban runoff. These are low-cost, natural and commercially available soil minerals. Contaminated surface runoff from urban areas is a major cause of concern for water quality and aquatic ecosystems worldwide. Pollution in urban areas is generated by a wide array of non-point sources, including vehicular transportation and building materials. Some of the most frequently detected pollutants in urban runoff are metals. Exhaust gases, tire wear and brake linings are major sources of such metals as Pb, Zn and Cu, while impregnated wood, plastics and galvanized surfaces may release As, Cd, Cr and Zn. Many metals have toxic effects on aquatic plants and animals, depending on metal speciation and bioavailability. The removal efficiency of pollutants in stormwater depends on treatment practices and on the properties the pollutant. The distribution of metals in urban runoff has shown, for example, that Pb is predominantly particle-associated, whereas Zn and Cd are present mainly in dissolved form. Many metals are also attached to colloids, which may act as carriers for contaminants, thereby facilitating their transport through conventional water treatment processes. Filtration of stormwater is one of the most promising techniques for removal of particulates, colloidal and truly dissolved pollutants, provided that effective filtration and adsorption media are used. Filtration and infiltration are used in a wide array of stormwater treatment methods e.g. porous paving, infiltration drains and rain gardens. Several soil minerals were investigated for their potential as stormwater filter materials. Laboratory batch tests were conducted to determine the adsorption capacity of these minerals. A synthetic stormwater was tested, with spiked concentrations corresponding to levels reported in urban runoff, ranging from 50-1,500 µg/L for Zn; 5-250 µg/L for Cu

  6. Characteristics of pellet-type adsorbents prepared from water treatment sludge and their effect on trimethylamine removal

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Junghyun; Park, Nayoung; Kim, Goun; Lee, Choul Ho; Jeon, Jong-Ki [Kongju National University, Cheonan (Korea, Republic of); Park, Young-Kwon [University of Seoul, Seoul (Korea, Republic of)

    2014-04-15

    We optimized the preparation method of pellet-type adsorbents based on alum sludge with the aim of developing a high-performance material for the adsorption of gaseous trimethylamine. Effects of calcination temperature on physical and chemical properties of pellet-type adsorbents were investigated. The porous structure and surface characteristics of the adsorbents were studied using N{sub 2} adsorption and desorption isotherms, scanning electron microscope, X-ray diffraction, temperature-programmed desorption of ammonia, and infrared spectroscopy of adsorbed pyridine. The adsorbents obtained from the water treatment sludge are microporous materials with well-developed mesoporosity. The pellet-type adsorbent calcined at 500 .deg. C had the highest percentage of micropore volume and the smallest average pore diameter. The highest adsorption capacity in trimethylamine removal attained over the pellet-type adsorbent calcined at 500 .deg. C can be attributed to the highest number of acid sites as well as the well-developed microporosity.

  7. Removal of adsorbent particles od copper ions by Jet flotation; Remocion de particulas adsorbentes de iones cobre por flotacion Jet

    Energy Technology Data Exchange (ETDEWEB)

    Santander, M.; Tapia, P.; Pavez, O.; Valderrama, L.; Guzman, D.

    2009-07-01

    The present study shows the results obtained on the removal of copper ions from synthetic effluents by using the adsorbent particles flotation technique (APF) in a Jet flotation cell (Jameson type). In a typical experimental run, a mineral with high quartz content was used as adsorbent particles in the adsorption and flotation experiments, to determine optimal pH conditions, adsorbent particles concentration; flotation reagents dosage and air/effluent flow ratio for applying in the Jet cell to maximize the efficiency of copper ions adsorptions and the removal of particles adsorbents containing the absorbed copper ions. The results indicate the at pH>7 and at adsorbent particles concentration of 2 kg.m{sup -}3, 99% of copper ions is adsorbed and, when the air/effluent flow ratio applied in the Jet cell is 0,2, 98% of absorbent particles containing the adsorbed copper ions is removed. (Author) 39 refs.

  8. Multiple sample setup for testing the hydrothermal stability of adsorbents in thermal energy storage applications

    International Nuclear Information System (INIS)

    Fischer, Fabian; Laevemann, Eberhard

    2015-01-01

    Thermal energy storage based on adsorption and desorption of water on an adsorbent can achieve high energy storage densities. Many adsorbents lose adsorption capacity when operated under unfavourable hydrothermal conditions during adsorption and desorption. The stability of an adsorbent against stressing hydrothermal conditions is a key issue for its usability in adsorption thermal energy storage. We built an experimental setup that simultaneously controls the hydrothermal conditions of 16 samples arranged in a matrix of four temperatures and four water vapour pressures. This setup allows the testing of potential adsorbents between temperatures of 50 °C and 350 °C and water vapour pressures of up to 32 kPa. A measurement procedure that allows the detection of the hydrothermal stability of an adsorbent after defined time spans has been designed. We verified the functionality of the multiple sample measurements with a microporous adsorbent, a zeolite NaMSX. The hydrothermal stability of this zeolite is tested by water uptake measurements. A standard deviation lower than 1% of the 16 samples for detecting the hydrothermal stability enables setting different conditions in each sample cell. Further, we compared the water uptake measurements by measuring their adsorption isotherms with the volumetric device BELSORP Aqua 3 from Bel Japan. (paper)

  9. Development of Silver-exchanged Adsorbents for the Removal of Fission Iodine from Alkaline Dissolution

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Woon; Lee, Seung Kon; Lee, Su Seung; Lee, Jun Sig [KAERI, Daejeon (Korea, Republic of); Kim, Sang Wook [Dongguk University, Gyeongju (Korea, Republic of)

    2016-05-15

    {sup 99} Mo is extracted from the filtrate solution through column-based multistep separation and purification process. In the process, removal of radio-impurities from the solution is essential to acquire high-quality fission {sup 99} Mo. Iodine is the main impurity having about 15% of total radioactivity among the whole fission products. Most of the iodine exists in the caustic dissolution as iodide form. In this study, silver-exchanged adsorbent is used to adsorb iodide from the solution. Adsorbed iodide can be recovered and recycled for radiopharmaceuticals. Compound is dried again. After heating ascorbic acid solution, solution is added to dried compound. Heat the mixture. After removing supernatant, the mixture is washed with hot distilled water and then cool distilled water in the order named. Finally, the mixture is heated and then recovering by using the sieve. In this study, silver-exchanged adsorbent is used to adsorb iodide from the solution. Adsorbed iodide can be recovered and recycled for radiopharmaceuticals. Silver-doped DAW-70 alumina by using silver mirror reaction is less impurities and simpler than method using ascorbic acid.

  10. Retention of radium from thermal waters on sand filters and adsorbents

    International Nuclear Information System (INIS)

    Elejalde, C.; Herranz, M.; Idoeta, R.; Legarda, F.; Romero, F.; Baeza, A.

    2007-01-01

    This study was focussed on laboratory experiences of retention of radium from one thermal water on sand filters and adsorbents, trying to find an easy method for the elimination in drinkable waters polluted with this natural radio-nuclide. A thermal water from Cantabria (Spain) was selected for this work. Retention experiences were made with columns of 35 mm of diameter containing 15 cm layers of washed river sand or 4 cm layers of zeolite A3, passing known volumes of thermal water at flows between 4 and 40 ml/min with control of the retained radium by determining the amount in the water after the treatment. The statistical analysis of data suggests that retention depends on the flow and the volume passed through the columns. As additional adsorbents were used kaolin and a clay rich in illite. Jar-test experiences were made agitating known weights of adsorbents with the selected thermal water, with addition of flocculants and determination of radium in filtrated water after the treatment. Data suggest that retention is related to the weight of adsorbent used, but important quantities of radium seem remain in solution for higher amounts of adsorbents, according to the statistical treatment of data. The elution of retained radium from columns or adsorbents, previously used in experiences, should be the aim of a future research

  11. Production of adsorbent from palm shell for radioactive iodine scrubbing process

    International Nuclear Information System (INIS)

    Mohamad Azman Che Mat Isa; Ku Halim Ku Hamid; Muhd Noor Muhd Yunus; Mohamad Puad Abu; Abdul Halim Badaruddin; Mohammad Nizammudin Abd Aziz; Muhd Ridwan Abdul Rahim

    2010-01-01

    The biggest biomass source in Malaysia comes from oil palm industry. According to the statistic of year 2004, Malaysia produced 40 million tones per year of biomass which 30 million tones of biomass originated from the oil palm industries. Therefore, the biomass waste such as palm kernel shell can be used to produce granular adsorbent for radioactive materials. For that reason, a newly system, called Rocking Kiln - Fluidized Bed (RK - FB) was developed to utilize large amount of the biomass to produce high value added product. Charcoal or chemically produced activated carbon could be produced by using the kiln. Washing process was introduced to remove particles, minerals and volatile matters from charcoal produced and then would create more surface area in the adsorbent by creating more active sites. In this research, the adsorbent produced was used to scrub iodine 131. In nuclear power reactor, iodine isotope 131 is produced during nuclear fission, and this elementary radioactive iodine may pollute exhaust air streams that could cause thyroid cancer. For removal of radioactive iodine, normally a potassium iodide - impregnated activated carbon (KI - AC) is used. Thus, a process will be developed to produce KI - AC and this product will be used to calculate the efficiency to remove the radioactive iodine 131.The results obtain show that adsorbent produced has a high potential to be used in radioactive adsorbing and likely more economics. This paper will elaborate further the experimental set-up of in Kiln - Fluidized Bed (RK - FB), adsorbent quality and radioactive scrubbing process. (author)

  12. Synthesis of magnetic ordered mesoporous carbon (Fe-OMC) adsorbent and its evaluation for fuel desulfurization

    Science.gov (United States)

    Farzin Nejad, N.; Shams, E.; Amini, M. K.

    2015-09-01

    In this work, magnetic ordered mesoporous carbon adsorbent was synthesized using soft templating method to adsorb sulfur from model oil (dibenzothiophene in n-hexane). Through this research, pluronic F-127, resorcinol-formaldehyde and hydrated iron nitrate were respectively used as soft template, carbon source and iron source. The adsorbent was characterized by X-ray diffraction, nitrogen adsorption-desorption isotherm and transmission electron microscopy. Nitrogen adsorption-desorption measurement revealed the high surface area (810 m2 g-1), maxima pore size of 3.3 nm and large pore volume (1.01 cm3 g-1) of the synthesized sample. The adsorbent showed a maximum adsorption capacity of 111 mg dibenzothiophene g-1 of adsorbent. Sorption process was described by the pseudo-second-order rate equation and could be better fitted by the Freundlich model, showing the heterogeneous feature of the adsorption process. In addition, the adsorption capacity of regenerated adsorbent was 78.6% of the initial level, after five regeneration cycles.

  13. Retention of radium from thermal waters on sand filters and adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Elejalde, C. [Dpto. de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria, Alameda de Urquijo s/n, 48013 Bilbao (Spain)]. E-mail: inpelsac@bi.ehu.es; Herranz, M. [Dpto. de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria, Alameda de Urquijo s/n, 48013 Bilbao (Spain); Idoeta, R. [Dpto. de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria, Alameda de Urquijo s/n, 48013 Bilbao (Spain); Legarda, F. [Dpto. de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria, Alameda de Urquijo s/n, 48013 Bilbao (Spain); Romero, F. [Dpto. de Ingenieria Quimica y del Medio Ambiente, Escuela Tecnica Superior de Ingenieria, Alameda de Urquijo s/n, 48013 Bilbao (Spain); Baeza, A. [Dpto. de Fisica, Facultad de Veterinaria, Universidad de Extremadura, Avda. Universidad s/n, 10071 Caceres (Spain)

    2007-06-18

    This study was focussed on laboratory experiences of retention of radium from one thermal water on sand filters and adsorbents, trying to find an easy method for the elimination in drinkable waters polluted with this natural radio-nuclide. A thermal water from Cantabria (Spain) was selected for this work. Retention experiences were made with columns of 35 mm of diameter containing 15 cm layers of washed river sand or 4 cm layers of zeolite A3, passing known volumes of thermal water at flows between 4 and 40 ml/min with control of the retained radium by determining the amount in the water after the treatment. The statistical analysis of data suggests that retention depends on the flow and the volume passed through the columns. As additional adsorbents were used kaolin and a clay rich in illite. Jar-test experiences were made agitating known weights of adsorbents with the selected thermal water, with addition of flocculants and determination of radium in filtrated water after the treatment. Data suggest that retention is related to the weight of adsorbent used, but important quantities of radium seem remain in solution for higher amounts of adsorbents, according to the statistical treatment of data. The elution of retained radium from columns or adsorbents, previously used in experiences, should be the aim of a future research.

  14. Comparative study of selenite adsorption on carbon based adsorbents and activated alumina.

    Science.gov (United States)

    Jegadeesan, G; Mondal, K; Lalvani, S B

    2003-08-01

    The sorption characteristics of carbon-based adsorbents such as activated carbon and chitin for the removal of selenite, Se (IV), an anionic, hazardous contaminant, are compared with those of alpha and gamma alumina. Batch experiments were conducted to determine the influence of pH, concentration of adsorbate, adsorbent loading and temperature on the sorption characteristics of the adsorbents. Generally, low pH of the solution resulted in favorable selenium removal. With the exception of activated carbon, uptakes decreased with increase in temperature. In comparison, chitin was found to be far less effective for the removal of Se (IV) from aqueous solutions. The data also showed that gamma alumina provided higher selenium removal percentages (99%) compared to alpha alumina (94%), activated carbon (87%) and chitin (49%). The selenite removal was found to decrease with increasing initial Se (IV) concentration in the solution. Adsorption capacities of the adsorbents are reported in terms of their Langmuir adsorption isotherms. The adsorption capacity (on unit mass basis) of the adsorbents for selenite is in the order: chitin (specific area (sa) = 9.58 m2 g(-1)) activated carbon (sa = 96.37 m2 g(-1)) < alpha alumina (sa = 6 m2 g(-1)) < gamma alumina (sa = 150 m2 g(-1)).

  15. Tetracycline removal from water by adsorption/bioadsorption on activated carbons and sludge-derived adsorbents.

    Science.gov (United States)

    Rivera-Utrilla, José; Gómez-Pacheco, Carla V; Sánchez-Polo, Manuel; López-Peñalver, Jesús J; Ocampo-Pérez, Raúl

    2013-12-15

    The objective of this study was to analyze the behavior of activated carbons with different chemical and textural natures in the adsorption of three tetracyclines (TCs) (tetracycline, oxytetracycline, and chlortetracycline). We also assessed the influence of the solution pH and ionic strength on the adsorption of these compounds and studied their removal by the combined use of microorganisms and activated carbon (bioadsorption). Sludge-derived materials were also used to remove TC from water. The capacity of these materials to adsorb TC was very high and was much greater than that of commercial activated carbon. This elevated adsorption capacity (512.1-672.0 mg/g) is explained by the high tendency of TC to form complex ions with some of the metal ions present in these materials. The medium pH and presence of electrolytes considerably affected TCs adsorption on commercial activated carbon. These results indicate that electrostatic adsorbent-adsorbate interactions play an important role in TC adsorption processes when conducted at pH values that produce TC deprotonation. The presence of bacteria during the TCs adsorption process decreases their adsorption/bioadsorption on the commercial activated carbon, weakening interactions between the adsorbate and the microfilm formed on the carbon surface. The adsorptive capacity was considerably lower in dynamic versus static regime, attributable to problems of TC diffusion into carbon pores and the shorter contact time between adsorbate and adsorbent. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Role of air bubbles overlooked in the adsorption of perfluorooctanesulfonate on hydrophobic carbonaceous adsorbents.

    Science.gov (United States)

    Meng, Pingping; Deng, Shubo; Lu, Xinyu; Du, Ziwen; Wang, Bin; Huang, Jun; Wang, Yujue; Yu, Gang; Xing, Baoshan

    2014-12-02

    Hydrophobic interaction has been considered to be responsible for adsorption of perfluorooctanesulfonate (PFOS) on the surface of hydrophobic adsorbents, but the long C-F chain in PFOS is not only hydrophobic but also oleophobic. In this study, for the first time we propose that air bubbles on the surface of hydrophobic carbonaceous adsorbents play an important role in the adsorption of PFOS. The level of adsorption of PFOS on carbon nanotubes (CNTs), graphite (GI), graphene (GE), and powdered activated carbon (PAC) decreases after vacuum degassing. Vacuum degassing time and pressure significantly affect the removal of PFOS by these adsorbents. After vacuum degassing at 0.01 atm for 36 h, the extent of removal of PFOS by the pristine CNTs and GI decreases 79% and 74%, respectively, indicating the main contribution of air bubbles to PFOS adsorption. When the degassed solution is recontacted with air during the adsorption process, the removal of PFOS recovers to the value obtained without vacuum degassing, further verifying the key role of air bubbles in PFOS adsorption. By theoretical calculation, the distribution of PFOS in air bubbles on the adsorbent surfaces is discussed, and a new schematic sorption model of PFOS on carbonaceous adsorbents in the presence of air bubbles is proposed. The accumulation of PFOS at the interface of air bubbles on the adsorbents is primarily responsible for its adsorption, providing a new mechanistic insight into the transport, fate, and removal of PFOS.

  17. Desorption of uranium from titanium-activated carbon composite adsorbent with acidic eluent, 1

    International Nuclear Information System (INIS)

    Hirotsu, Takahiro; Fujii, Ayako; Sakane, Kohji; Katoh, Shunsaku; Sugasaka, Kazuhiko

    1984-01-01

    An investigation was carried out on the desorption of uranium from titanium-activated carbon composite adsorbent with acidic eluent by the batch process. The rate of desorption of uranium with acidic eluent depended on temperature, showing an increase as the temperature was raised. But the rate of desorption with acidic eluent was less dependent on temperature than that obtained when mixed eluent of sodium carbonate-sodium hydrogencarbonate was used. The rate of desorption of uranium did not vary in the range of concentration from 0.3 to 0.5 N, and the rate of desorption with sulfuric acid was slightly higher than that obtained when hydrochloric acid was used. The amount of dissolved titanium decreased as the ratio of adsorbent to eluent (RAE) was increased. At RAE of 10 %, the percentage of dissolved titanium (DTI) was below 0.38 % with sulfuric acid, below 0.7 % with hydrochloric acid. These values were found to be higher than the ones with the carbonate eluent. The elements except uranium, which were adsorbed on the adsorbent, were eluted simultaneously with acidic eluent. The regeneration of the adsorbent after desorption, therefore, was found to be unnecessary. In a repeated test of adsorption-desorption treatment up to five times, the percentage of uranium adsorbed from natural sea water was approximately constant of 85 %. From these results, the application of column process to the desorption of uranium with acidic eluent at room temperature was proposed to be feasible. (author)

  18. Desorption of uranium from titanium-activated carbon composite adsorbent with acidic eluent, (1)

    International Nuclear Information System (INIS)

    Hirotsu, Takahiro; Fujii, Ayako; Sakane, Kohji; Katoh, Shunsaku; Sugasaka, Kazuhiko

    1983-01-01

    An investigation was carried out on the desorption of uranium from titanium-activated carbon composite adsorbent with acidic eluent by the batch process. The rate of desorption of uranium with acidic eluent depended on temperature, showing an increase as the temperature was raised. But the rate of desorption with acidic eluent was less dependent on temperature than that obtained when mixed eluent of sodium carbonate-sodium hydrogencarbonate was used. The difference of the rate of desorption of uranium in the range of concentration from 0.3 to 0.5N was not found, and the rate of desorption with sulfuric acid was slightly higher than that obtained when hydrochloric acid was used. The amount of dissolved titanium decreased as the ratio of adsorbent to eluent (RAE) was increased. At RAE of 10%, the percentage of dissolved titanium (DTI) was below 0.38% with sulfuric acid, below 0.7% with hydrochloric acid. These values were found to be higher than the ones with the carbonate eluent. The elements except uranium, which were adsorbed on the adsorbent, were eluted simultaneously with acidic eluent. The regeneration of the adsorbent after desorption, therefore, was found to be unnecessary. In a repeated test of adsorption-desorption treatment up to five times, the percentage of uranium adsorbed from natural sea water was approximately constant of 85%. From these results, the application of column process to the desorption of uranium with acidic eluent at room temperature was proposed to be feasible. (author)

  19. Desorption of uranium from titanium-activated carbon composite adsorbent with acidic eluent, 2

    International Nuclear Information System (INIS)

    Hirotsu, Takahiro; Fujii, Ayako; Sakane, Kohji; Katoh, Shunsaku; Sugasaka, Kazuhiko

    1984-01-01

    The desorption of uranium from the granular titanium-activated carbon composite adsorbent (concentration of uranium: 25.5 mg/1-Ad), which adsorbed uranium from natural sea water, was examined by the column process with acidic eluent at room temperature. The column operation was able to be carried out without destruction of the granular adsorbent by the generation of the carbon dioxide, and free from disturbance of the eluent flow by precipitate of calcium sulfate dihydrate with sulfuric acid eluent. The amount of acid consumption by the adsorbent was 0.87 eq/1-Ad. The alkaline earth metals were eluted in the range of elution volume below 2 1/1-Ad, whereas uranium, iron, and titanium were eluted above 2 1/1-Ad. Therefore, uranium was separable from the alkaline earth metals which were adsorbed in the most quantity in the adsorbent. In the range of elution volume 2 to 12 1/1-Ad, the percentage of desorbed uranium and the concentration ratio of uranium were 80 %, 680 with 0.5 N sulfuric acid, and 59 %, 490 with 0.5 N hydrochloric acid, respectively. The percentage of dissolved titanium (DTI) was 0.3 % with 0.5 N sulfuric acid, 0.26 % with 0.5 N hydrochloric acid in the same range. (author)

  20. Catalytic isotope exchange reaction between deuterium gas and water pre-adsorbed on platinum/alumina

    International Nuclear Information System (INIS)

    Iida, Itsuo; Kato, Junko; Tamaru, Kenzi.

    1976-01-01

    The catalytic isotope exchange reaction between deuterium gas and the water pre-adsorbed on Pt/Al 2 O 3 was studied. At reaction temperatures above 273 K, the exchange rate was proportional to the deuterium pressure and independent of the amount of adsorbed water, which suggests that the rate determining step is the supply of deuterium from the gas phase. Its apparent activation energy was 38 kJ mol -1 . Below freezing point of water, the kinetic behaviour was different from that above freezing point. At higher deuterium pressures the rate dropped abruptly at 273 K. Below the temperature the apparent activation energy was 54 kJ mol -1 and the exchange rate depended not on the deuterium pressure but on the amount of the pre-adsorbed water. At lower pressures, however, the kinetic behaviour was the same as the above 273 K, till the rate of the supply of deuterium from the gas phase exceeded the supply of hydrogen from adsorbed water to platinum surface. These results suggest that below 273 K the supply of hydrogen is markedly retarded, the state of the adsorbed water differing from that above 273 K. It was also demonstrated that when the adsorbed water is in the state of capillary condensation, the exchange rate becomes very small. (auth.)