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Sample records for neptunium filtrate solution

  1. Precipitation of neptunium dioxide from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, K E

    1999-12-01

    Tens of thousands of metric tons of highly radioactive, nuclear waste have been generated in the US. Currently, there is no treatment or disposal facility for these wastes. Of the radioactive elements in high-level nuclear waste, neptunium (Np) is of particular concern because it has a long half-life and may potentially be very mobile in groundwaters associated with a proposed underground disposal site at Yucca Mountain, Nevada. Aqueous Np concentrations observed in previous, short-term solubility experiments led to calculated potential doses exceeding proposed long-term regulatory limits. However, thermodynamic data for Np at 25 C showed that these observed aqueous Np concentrations were supersaturated with respect to crystalline NpO{sub 2}. It was hypothesized that NpO{sub 2} is the thermodynamically stable solid phase in aqueous solution, but it is slow to form in an aqueous solution of NpO{sub 2}{sup +} on the time scale of previous experiments. The precipitation of NpO{sub 2} would provide significantly lower aqueous Np concentrations leading to calculated doses below proposed regulatory limits. To test this hypothesis, solubility experiments were performed at elevated temperature to accelerate any slow precipitation kinetics. Ionic NpO{sub 2}{sup +} (aq) was introduced into very dilute aqueous solutions of NaCl with initial pH values ranging from 6 to 10. The reaction vessels were placed in an oven and allowed to react at 200 C until steady-state aqueous Np concentrations were observed. In all cases, aqueous Np concentrations decreased significantly from the initial value of 10{sup {minus}4} M. The solids that formed were analyzed by x-ray powder diffraction, x-ray absorption spectroscopy, and scanning electron microscopy. The solids were determined to be high-purity crystals of NpO{sub 2}. This is the first time that crystalline NpO{sub 2} has been observed to precipitate from NpO{sub 2}{sup +}(aq) in near-neutral aqueous solutions. The results obtained

  2. Photochemical reactions of neptunium in nitric acid solution containing photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Fukasawa, Tetsuo; Kawamura, Fumio (Hitachi Ltd., Ibaraki (Japan). Energy Research Lab.)

    1991-01-01

    Photochemical oxidation and reduction behaviors of neptunium were preliminarily investigated in 3 mol/l nitric acid solution. Nitric acid of 3 mol/l simulated the high level waste solution from a spent fuel reprocessing process. Concentrations of Np(V), Np(VI) and nitrous acid were determined with a photospectrometer, and solution potential with an electrode. Without additives, Np(VI) was reduced to Np(V) by nitrous acid which was photolytically generated from nitric acid. With a scavenger for nitrous acid, Np(V) was oxidized to extractable Np(VI) by a photolytically generated oxidizing reagent which were predicted by the solution potential measurement. The reduction rate was higher than the oxidation rate because of the larger quantity and higher reactivity of nitrous acid than an oxidizing reagent. Photocatalyst was proved to be effective for the oxidation of Np(V) to Np(VI). (author).

  3. Cake Filtration in Viscoelastic Polymer Solutions

    Science.gov (United States)

    Surý, Alexander; Machač, Ivan

    2009-07-01

    In this contribution, the filtration equations for a cake filtration in viscoelastic fluids are presented. They are based on a capillary hybrid model for the flow of a power law fluid. In order to express the elastic pressure drop excess in the flow of viscoelastic filtrate through the filter cake and filter screen, modified Deborah number correction functions are included into these equations. Their validity was examined experimentally. Filtration experiments with suspensions of hardened polystyrene particles (Krasten) in viscoelastic aqueous solutions of polyacryl amides (0.4% and 0.6%wt. Kerafloc) were carried out at a constant pressure on a cylindrical filtration unit using filter screens of different resistance.

  4. Ultrasonic filtration of industrial chemical solutions

    Science.gov (United States)

    Cosma, T.

    1974-01-01

    The practical results obtained as a result of filtering industrial chemical solutions under continuous flow conditions with the aid of an ultrasonic filter are presented. The main part of the assembly consists of an ultrasonic generator with an output power of about 400 W and the filtration assembly, in which there is a magnetostrictive amplifier constructed for 20.5 kHz. In addition to ensuring a continuous flow of filtered solution, ultrasonic filters can be replaced or cleaned at intervals of time that are 8-10 times greater than in the case of mechanical filters. They yield considerably better results as far as the size of the filtered particles is concerned. The parameters on which filtration quality depends are also presented.

  5. Investigation into formation of nanoparticles of tetravalent neptunium in slightly alkaline aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Husar, Richard

    2015-08-20

    Considering the worldwide growing discharge of minor actinides and the current need for geological disposal facilities for radioactive waste, this work provides a contribution to the safety case concerning Np transport if it would be released from deep repository sites and moving from alkaline cement conditions (near-field) to more neutral environmental conditions (far-field). The reducing conditions in a nuclear waste repository render neptunium tetravalent, which is assumed to be immobile in aqueous environment due to the low solubility solution of Np(IV). For tetravalent actinide nuclides, the most significant transport should occur via colloidal particles. This work demonstrates the formation of intrinsic neptunium dioxide nanocrystals and amorphous Np(IV) silica colloids under environmentally relevant conditions. The dissociation of the initial soluble Np(IV) complex (i.e. [Np(IV)(CO{sub 3}){sub 5}]{sup 6-}) induces the intrinsic formation of nanocrystalline NpO{sub 2} in the solution phase. The resulting irregularly shaped nanocrystals with an average size of 4 nm exhibit a face-centered cubic (fcc), fluorite-type structure (space group Fm anti 3m). The NCs tend to agglomerate under ambient conditions due to the weakly charged hydrodynamic surface at neutral pH (zetapotential ζ ∝0 mV). The formation of micron-sized agglomerates, composed of nanocrystals of 2-5 nm in size, and the subsequent precipitation cause immobilization of the major amount of Np(IV) in the Np carbonate system. Agglomeration of NpO{sub 2} nanocrystals in dependence on time was indicated by PCS and UV-vis absorption spectroscopy with the changes of baseline characteristics and absorption maximum at 742 nm. Hitherto, unknown polynuclear species as intermediate species of NpO{sub 2} nanocrystal formation were isolated from solution and observed by HR-TEM. These polynuclear Np species appear as dimers, trimers and hexanuclear compounds in analogy with those reported for other actinides

  6. Analytical separation of traces of neptunium from highly concentrated uranium solutions using reversed phase chromatography in the TLA-HNO{sub 3} system; Separation analytique de traces de neptunium de solutions tres concentrees en uranium par chromatographie en phase inversee dans le systeme TLA-HNO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Gourisse, D.; Chesne, A. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1967-07-01

    The neptunium (IV) partition between nitric acid-uranyl nitrate solutions and Kel F powder coated with a trilauryl-ammonium-nitrate solution has been studied in order to determine the optimum operating conditions for separating neptunium from uranium. The reversed phase partition chromatography was performed by passing a 2 N HNO{sub 3} 0,1 M Fe{sup ++} solution containing neptunium plutonium and up to 100 g/1 of uranium through a column of TLAHNO{sub 3} - Kel F beads. After washing the column with a N HNO{sub 3} solution containing a reducing agent, the neptunium is eluted by a sulfuric acid-nitric acid mixture. This method was proved to be very selective for tetravalent neptunium; therefore leading to a good separation from fission products, plutonium and uranium. It has been applied to solutions in which the molar ratio U/Np was greater than 10{sup 10}. The only limitation depends upon the sensitivity of the neptunium determination in dilute solutions. (author) [French] L'etude du partage du neptnunium tetravalent entre la TLA adsorbee sur la poudre de Kel-F et les solutions aqueuses concentrees en uranium permet de definir les conditions operatoires d'une separation analytique des traces de Np de ces solutions par chromatographie en phase inversee. La separation s'effectue par fixation du Np d'une solution 2 N HNO{sub 3}; 0,1 M Fe{sup ++}, U {<=} 100 g/1 sur une colonne de poudre TLAHNO{sub 3} - Kel F. Apres lavage par une solution reductrice 1 N HNO{sub 3}, le neptunium est elue par une solution sulfonitrique. Cette methode, tres selective par rapport aux produits de fission et offrant des facteurs de decontamination eIeves en Pu a ete appliquee a des solutions dans lesquelles U/Np > 10{sup 10}. Ses limites sunt fixees par la sensibilite des methodes d'analyse du neptunium en solution aqueuse diluee. (auteur)

  7. A New Solution of the Deep Bed Filtration

    OpenAIRE

    Saatçı, A.M.; Halilsoy, Mustafa

    1987-01-01

    We present a more general solution of the standard deep bed filtration equations which explains the initial improvement of effluent quality as a suspension passes through a porous medium. Our solution gives a good fit to experimental data and predicts the experimental observations. The file in this item is the publisher version (published version) of the article.

  8. Short note on the hydrolysis and complexation of neptunium(IV) in HEPES solution

    Energy Technology Data Exchange (ETDEWEB)

    Dahou, S. [CEA, Bagnols-sur-Ceze (France). Radiochemistry and Processes Dept.; Montpellier I Univ. (France). IBMM; Hennig, C.; Scheinost, A.C. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany); Moisy, P.; Petit, S. [CEA, Bagnols-sur-Ceze (France). Radiochemistry and Processes Dept.; Subra, G. [Montpellier I Univ. (France). IBMM; Vidaud, C. [CEA, Bagnols-sur-Ceze (France). iBEB/SBTN/LEPC; Auwer, C. den [CEA, Bagnols-sur-Ceze (France). Radiochemistry and Processes Dept.; Nice Sophia Antipolis Univ. (France). ICN, UMR 7272

    2013-08-01

    The speciation of actinides in environmental or biological media is often difficult to assess because it involves complex media. We would like to report here on the properties of Np(IV) cation in the well known biological HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) buffer medium. HEPES has been targeted because the possibility to use this biological buffer in actinide toxicological studies presents several advantages although the possible effects of concentrated HEPES medium on the hydrolysis of the actinides (in particular at oxidation state +IV) has not been studied yet. A combination of spectrophotometric and EXAFS measurements at the Np LIII edge shows that stable hydrolyzed neptunium(IV) clusters are obtained between pH 2.5 and 4. In a second step, in order to better understand the reactivity of these hydrolysis species formed in HEPES, the effect of a strong chelating ligands such as the hydroxamic acid (HA) or desferrioxamine (DFO) siderophores has been also investigated using spectrophotometry and EXAFS. Upon addition of HA or DFO, the hydrolyzed clusters of Np(IV) are unstable and monomeric complexes are formed and yield Np environments that are very similar to that of crystallized Pu-DFOE complex [Al(H{sub 2}O){sub 6}][Pu(DFE)(H{sub 2}O){sub 3}]{sub 2}(CF{sub 3}SO{sub 3}){sub 5} . 10H{sub 2}O reported in the literature. (orig.)

  9. Particle clogging in porous media. Filtration of a smectite solution

    Energy Technology Data Exchange (ETDEWEB)

    Richards, Tobias (Chalmers University of Technology, Goeteborg (Sweden))

    2010-01-15

    The goal of this project is to find out if it is possible for bentonite clay to self heal during leaching with deionized water. The investigation has focused on the formation of a filter cake made of accessory material from MX 80 and the separation of solid material when a smectite solution (1%) is pushed through the cake using a pressure difference of 5 bar. It was also in the scope of this project to design and build the necessary equipment for these experiments. In the literature review it was not found any example that the phenomenon of clogging has been used as a self-healing method previously. It was rather separated also between the clogging of a filter cake (deep bed filtration or cake filtration) and the filtration of colloidal particles. Probably because the latter are in such low concentrations in natural systems and the focus have mainly been in the transport properties of colloids within a filter cake or deep bed filter. An experimental equipment was designed and built. It consists of seven filtration cells that could operate in parallel. All of them are connected to the same source of pressure to ensure equal conditions. A system was also prepared to prevent air from dissolving in the solution because it could create an unwanted expansion in the filter cake due to lower solubility at lower pressure. The experiment showed good separation of smectite particles from the solution when it passed through the filter cake. In all tested cases, the separation was almost complete after long enough time, indicating that the cake has small enough pores to act as a geometrical hinder for the small particles. Comparison between the materials prepared at Chalmers University of Technology and at Clay Technology showed a very good agreement indicating similar properties of the produced smectite

  10. Numerical Solutions of Mechanical Turbulent Filtration Equation Used in Mechatronics and Micro Mechanic

    Directory of Open Access Journals (Sweden)

    Hassan Fathabadi

    2013-08-01

    Full Text Available In this study, several novel numerical solutions are presented to solve the turbulent filtration equation and its special case called “Non-Newtonian mechanical filtration equation”. The turbulent filtration equation in porous media is a very important equation which has many applications to solve the problems appearing especially in mechatronics, micro mechanic and fluid mechanic. Many applied mechanical problems can be solved using this equation. For example, non-Newtonian mechanical filtration equation solves many filtration problems in fluid mechanic. The novel proposed discrete numerical solutions are simulated in MATLAB/simulink environment to validate the theoretically numerical solutions and proofing that the proposed numerical solutions are realizable.

  11. DISSOLUTION OF NEPTUNIUM OXIDE RESIDUES

    Energy Technology Data Exchange (ETDEWEB)

    Kyser, E

    2009-01-12

    This report describes the development of a dissolution flowsheet for neptunium (Np) oxide (NpO{sub 2}) residues (i.e., various NpO{sub 2} sources, HB-Line glovebox sweepings, and Savannah River National Laboratory (SRNL) thermogravimetric analysis samples). Samples of each type of materials proposed for processing were dissolved in a closed laboratory apparatus and the rate and total quantity of off-gas were measured. Samples of the off-gas were also analyzed. The quantity and type of solids remaining (when visible) were determined after post-dissolution filtration of the solution. Recommended conditions for dissolution of the NpO{sub 2} residues are: Solution Matrix and Loading: {approx}50 g Np/L (750 g Np in 15 L of dissolver solution), using 8 M nitric acid (HNO{sub 3}), 0.025 M potassium fluoride (KF) at greater than 100 C for at least 3 hours. Off-gas: Analysis of the off-gas indicated nitric oxide (NO), nitrogen dioxide (NO{sub 2}) and nitrous oxide (N{sub 2}O) as the only identified components. No hydrogen (H{sub 2}) was detected. The molar ratio of off-gas produced per mole of Np dissolved ranged from 0.25 to 0.4 moles of gas per mole of Np dissolved. A peak off-gas rate of {approx}0.1 scfm/kg bulk oxide was observed. Residual Solids: Pure NpO{sub 2} dissolved with little or no residue with the proposed flowsheet but the NpCo and both sweepings samples left visible solid residue after dissolution. For the NpCo and Part II Sweepings samples the residue amounted to {approx}1% of the initial material, but for the Part I Sweepings sample, the residue amounted to {approx}8 % of the initial material. These residues contained primarily aluminum (Al) and silicon (Si) compounds that did not completely dissolve under the flowsheet conditions. The residues from both sweepings samples contained minor amounts of plutonium (Pu) particles. Overall, the undissolved Np and Pu particles in the residues were a very small fraction of the total solids.

  12. Synthesis, phase structure and microstructure of monazite-type Ce1-xPrxPO4 solid solutions for immobilization of minor actinide neptunium

    Science.gov (United States)

    Zeng, Pan; Teng, Yuancheng; Huang, Yi; Wu, Lang; Wang, Xiaohuan

    2014-09-01

    Praseodymium was used as the surrogate for trivalent minor actinide neptunium, and a complete series of pure monazite-type Ce1-xPrxPO4 (x = 0-1) solid solutions were successfully prepared by the solid state reaction. The effects of calcining temperature, holding time and Pr content on the structure of Ce1-xPrxPO4 solid solutions were investigated. The results show that although Pr6O11 (Pr23+Pr44+O11) exists two stabilized oxidation states, there has been no tetravalent praseodymium phosphate during the synthesis process. The optimized temperature for the synthesis of Ce0.8Pr0.2PO4 solid solution is more than 1100 °C, and a hypothetical reaction mechanism is also proposed. Besides, the crystalline grains coarsen as the increasing of holding time. The linear variation of unit cell parameters and a gradual hypsochromic shift in the Raman spectra are observed with the increase of Pr content, indicating that cerium is progressively replaced by praseodymium and Ce1-xPrxPO4 solid solutions were prepared.

  13. Neptunium_Oxide_Precipitation_Kinetics_AJohnsen

    Energy Technology Data Exchange (ETDEWEB)

    Johnsen, A M; Roberts, K E; Prussin, S G

    2012-06-08

    We evaluate the proposed NpO{sub 2}{sup +}(aq)-NpO{sub 2}(cr) reduction-precipitation system at elevated temperatures to obtain primary information on the effects of temperature, ionic strength, O{sub 2} and CO{sub 2}. Experiments conducted on unfiltered solutions at 10{sup -4} M NpO{sub 2}{sup +}(aq), neutral pH, and 200 C indicated that solution colloids strongly affect precipitation kinetics. Subsequent experiments on filtered solutions at 200, 212, and 225 C showed consistent and distinctive temperature-dependent behavior at reaction times {le} 800 hours. At longer times, the 200 C experiments showed unexpected dissolution of neptunium solids, but experiments at 212 C and 225 C demonstrated quasi steady-state neptunium concentrations of 3 x 10{sup -6} M and 6 x 10{sup -6} M, respectively. Solids from a representative experiment analyzed by X-ray diffraction were consistent with NpO{sub 2}(cr). A 200 C experiment with a NaCl concentration of 0.05 M showed a dramatic increase in the rate of neptunium loss. A 200 C experiment in an argon atmosphere resulted in nearly complete loss of aqueous neptunium. Previously proposed NpO{sub 2}{sup +}(aq)-NpO{sub 2}(cr) reduction-precipitation mechanisms in the literature specified a 1:1 ratio of neptunium loss and H{sup +} production in solution over time. However, all experiments demonstrated ratios of approximately 0.4 to 0.5. Carbonate equilibria can account for only about 40% of this discrepancy, leaving an unexpected deficit in H+ production that suggests that additional chemical processes are occurring.

  14. Process chemistry of neptunium. Part II

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, N.; Ramaniah, M.V.; Patil, S.K.; Ramakrishna, V.V.; Swarup, R.; Chadha, A.; Avadhany, G.V.N.

    1974-07-01

    The oxidation state analysis of neptunium in the aqueous feed solution from the Plutonium Plant at Trombay was carried out and it was found that neptunium existed mainly as Np(V) in the feed solution. Batch extraction data for Np(IV) and Np(VI) into 30% TBP/Shell Sol T at different aqueous nitric acid concentration and uranium saturation of the organic phase were obtained at 45 deg C and 60 deg C and the results are summarized. The distribution coefficients of Np(IV) and Np(VI) were obtained as a function of TBP concentration and the data are reported. The effect of nitrous acid on the extraction of neptunium, present in the aqueous phase as Np(IV) and Np(V), by 30% TBP was studied and the data obtained are given. The data on the rate of reduction of NP(VI) and Np(V) to Np(IV) by U(IV) were obtained for different U(IV) and nitric acid concentrations. Some redox reactions involving Np(IV), Pu(IV) and V(V) were investigated and their possible application in the purex process for neptunium recovery were explored. (auth)

  15. Approximate solutions to the deep bed filtration problem; Solucoes aproximadas para o problema de deposicao profunda

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Julio M.; Marchesin, Dan [Instituto de Matematica Pura e Aplicada (IMPA), Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The deep bed filtration problem is closely related to secondary oil recovery. In this work we derive explicit solutions to two filtration problems. The filtration function varies non-linearly with the Darcy speed and linearly with the deposition, but very little. The first solution is built by the method of perturbations and although it is only an approximation it is available in multiple symmetries, including the radial geometry used in the field. The main motivation is the validation of numerical methods. The second solution is exact but it is only available in the linear symmetry, i.e., laboratory geometry. We use it to verify the accuracy of the first solution, but it can also be used to simulate the deposition in experiments. (author)

  16. Uniqueness of self-similar very singular solution for non-Newtonian polytropic filtration equations with gradient absorption

    Directory of Open Access Journals (Sweden)

    Hailong Ye

    2015-04-01

    Full Text Available Uniqueness of self-similar very singular solutions with compact support are proved for the non-Newtonian polytropic filtration equation with gradient absorption $$ \\frac{\\partial u}{\\partial t} =\\hbox{div}(|\

  17. Synthesis, phase structure and microstructure of monazite-type Ce{sub 1−x}Pr{sub x}PO{sub 4} solid solutions for immobilization of minor actinide neptunium

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Pan; Teng, Yuancheng, E-mail: tyc239@163.com; Huang, Yi; Wu, Lang; Wang, Xiaohuan

    2014-09-15

    Praseodymium was used as the surrogate for trivalent minor actinide neptunium, and a complete series of pure monazite-type Ce{sub 1−x}Pr{sub x}PO{sub 4} (x = 0–1) solid solutions were successfully prepared by the solid state reaction. The effects of calcining temperature, holding time and Pr content on the structure of Ce{sub 1−x}Pr{sub x}PO{sub 4} solid solutions were investigated. The results show that although Pr{sub 6}O{sub 11} (Pr{sub 2}{sup 3+}Pr{sub 4}{sup 4+}O{sub 11}) exists two stabilized oxidation states, there has been no tetravalent praseodymium phosphate during the synthesis process. The optimized temperature for the synthesis of Ce{sub 0.8}Pr{sub 0.2}PO{sub 4} solid solution is more than 1100 °C, and a hypothetical reaction mechanism is also proposed. Besides, the crystalline grains coarsen as the increasing of holding time. The linear variation of unit cell parameters and a gradual hypsochromic shift in the Raman spectra are observed with the increase of Pr content, indicating that cerium is progressively replaced by praseodymium and Ce{sub 1−x}Pr{sub x}PO{sub 4} solid solutions were prepared.

  18. Effects of feed solution chemistry on low pressure reverse osmosis filtration of cesium and strontium

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Shiyuan, E-mail: dingshiyuan@bnu.edu.cn [State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Haidian District, Beijing 100875 (China); Yang, Yu, E-mail: yangyu@bnu.edu.cn [State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Haidian District, Beijing 100875 (China); Huang, Haiou, E-mail: huanghaiou@bnu.edu.cn [State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Haidian District, Beijing 100875 (China); Liu, Hengchen, E-mail: 799599501@qq.com [State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Haidian District, Beijing 100875 (China); Hou, Li-an, E-mail: houlian678@hotmail.com [State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Haidian District, Beijing 100875 (China); Xi’an High-Tech Institute, No. 2, Tongxin Street, Baqiao District, Xi’an 710025 (China)

    2015-08-30

    Highlights: • A low pressure spiral wound RO membrane can reject Cs and Sr efficiently. • The rejection of Cs and Sr is dependent on feed pH and co-existing ions. • Donnan exclusion and electrostatic interaction govern the rejection of Cs and Sr. • The differences of filtration mechanism were influenced by the size of ions. • Sr could strengthen the irreversible membrane fouling resistance with HA. - Abstract: The objective of this study was to identify the removal mechanisms of radionuclides by reverse osmosis (RO) membranes under conditions relevant to full-scale water treatment. For this purpose, the effects of feed solution chemistry on the removal of Cs and Sr by a low pressure RO system was investigated by systematically varying membrane surface charge, ionic composition, and organic matter concentrations. The results showed that the effects of solution chemistry on the filtration of Cs and Sr were related to their hydrated ionic radius, resulting in the predominance of the Donnan’s effect and electrostatic interactions, respectively. Consequently, the rejection of Cs increased more pronouncedly than Sr with the increases of feed concentration. Due to the Donnan’s effect, different anions decreased the rejection of Cs to different extents in accordance to the order of anions’ radii as SO{sub 4}{sup 2−} > Cl{sup −} > NO{sub 3}{sup −} > F{sup −}. The variations in Sr rejection were influenced by the electrostatic interactions between Sr{sup 2+} and the membrane. In addition, humic acid (HA) lowered the rejection of Cs and caused significant membrane flux decline, but did not change the rejection of Sr. Sr also aggravated HA fouling of the membrane.

  19. An approximate analytical solution to the ultra-filtration profile in a hemodialysis process between parallel porous plates

    Institute of Scientific and Technical Information of China (English)

    LU JunFeng; LU WenQiang

    2008-01-01

    In a hemodialysis process, the blood that runs through straight channels exchanges substances with the dialysate through a semi-permeable membrane. The waste products, such as urea and creatinine, are therefore removed from the plasma by the membrane. In the analysis of this process, determination of the ultra-filtration profile along the porous membrane surface remains a difficult problem. In this work, an analytical solution to the derivation of such a profile was detailed, and the feasibility of this solution was discussed. The ultra-filtration profile was found to be in a cosine shape.

  20. Investigations into the fouling mechanism of parvovirus filters during filtration of freeze-thawed mAb drug substance solutions.

    Science.gov (United States)

    Barnard, James G; Kahn, David; Cetlin, David; Randolph, Theodore W; Carpenter, John F

    2014-03-01

    Filtration to remove viruses is one of the single most expensive steps in the production of mAb drug products. Therefore, virus filtration steps should be fully optimized, and any decline in flow rates warrants investigation into the causes of such membrane fouling. In the current study, it was found that freezing and thawing of a mAb bulk drug solution caused a substantial decrease in viral filter membrane flow rate. Freezing and thawing also caused formation of aggregates and particles across a broad size range, including particles that could be detected by microflow imaging (≥1 μm in size). However, removal of these particles offered little protection against flow rate decline during viral filtration. Further investigation revealed that trace amounts of aggregates (ca. 10⁻⁶ of the total mass of protein in solution) approximately 20-40 nm in size were primarily responsible for the observed membrane fouling.

  1. pH-Dependent retention changes during membrane filtration of aluminum-coagulated solutions and the effect of precentrifugation.

    Science.gov (United States)

    Bérubé, Denis; Dorea, Caetano

    2013-03-19

    During jar tests on alum-based drinking water treatment, dissolved Al determinations on solutions coagulated at pH ≥ 6.5 were not reproducible. These determinations were performed by inductively coupled plasma mass spectrometry after syringe filtration (0.45 μm polyethersulfone membrane). In order to better define these anomalies, the filtrates were collected in sequential fractions of 7.5 mL. At coagulation pHs of 6.5 and 7.0, retention changes were demonstrated by large filtrate concentration reductions at all temperatures tested (0.1, 5.0, and 17.0 °C). In all cases, the concentrations converged to levels low range of the minimum solubility domain, at pHs 5.5 and 6.0. The retention changes were also eliminated by precentrifugation (7000 g for 45 min; pH 6.5-7.2). At weaker precentrifugation conditions, as well as by varying membrane surface area or membrane fouling, the filtrate concentrations behaved according to a barrier buildup at the membrane-solution interface by unsettled flocculation residuals. The influence of flocculation time and temperature emphasized the importance of reaction rates, which could be enhanced at the interface by concentration polarization effects. These phenomena have implications on analytical protocols and on filtration in full-scale treatment.

  2. Effects of feed solution chemistry on low pressure reverse osmosis filtration of cesium and strontium.

    Science.gov (United States)

    Ding, Shiyuan; Yang, Yu; Huang, Haiou; Liu, Hengchen; Hou, Li-an

    2015-08-30

    The objective of this study was to identify the removal mechanisms of radionuclides by reverse osmosis (RO) membranes under conditions relevant to full-scale water treatment. For this purpose, the effects of feed solution chemistry on the removal of Cs and Sr by a low pressure RO system was investigated by systematically varying membrane surface charge, ionic composition, and organic matter concentrations. The results showed that the effects of solution chemistry on the filtration of Cs and Sr were related to their hydrated ionic radius, resulting in the predominance of the Donnan's effect and electrostatic interactions, respectively. Consequently, the rejection of Cs increased more pronouncedly than Sr with the increases of feed concentration. Due to the Donnan's effect, different anions decreased the rejection of Cs to different extents in accordance to the order of anions' radii as SO4(2-)>Cl(-)>NO3(-)>F(-). The variations in Sr rejection were influenced by the electrostatic interactions between Sr(2+) and the membrane. In addition, humic acid (HA) lowered the rejection of Cs and caused significant membrane flux decline, but did not change the rejection of Sr. Sr also aggravated HA fouling of the membrane. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Organometallic neptunium(III) complexes.

    Science.gov (United States)

    Dutkiewicz, Michał S; Farnaby, Joy H; Apostolidis, Christos; Colineau, Eric; Walter, Olaf; Magnani, Nicola; Gardiner, Michael G; Love, Jason B; Kaltsoyannis, Nikolas; Caciuffo, Roberto; Arnold, Polly L

    2016-08-01

    Studies of transuranic organometallic complexes provide a particularly valuable insight into covalent contributions to the metal-ligand bonding, in which the subtle differences between the transuranium actinide ions and their lighter lanthanide counterparts are of fundamental importance for the effective remediation of nuclear waste. Unlike the organometallic chemistry of uranium, which has focused strongly on U(III) and has seen some spectacular advances, that of the transuranics is significantly technically more challenging and has remained dormant. In the case of neptunium, it is limited mainly to Np(IV). Here we report the synthesis of three new Np(III) organometallic compounds and the characterization of their molecular and electronic structures. These studies suggest that Np(III) complexes could act as single-molecule magnets, and that the lower oxidation state of Np(II) is chemically accessible. In comparison with lanthanide analogues, significant d- and f-electron contributions to key Np(III) orbitals are observed, which shows that fundamental neptunium organometallic chemistry can provide new insights into the behaviour of f-elements.

  4. Organometallic neptunium(III) complexes

    Science.gov (United States)

    Dutkiewicz, Michał S.; Farnaby, Joy H.; Apostolidis, Christos; Colineau, Eric; Walter, Olaf; Magnani, Nicola; Gardiner, Michael G.; Love, Jason B.; Kaltsoyannis, Nikolas; Caciuffo, Roberto; Arnold, Polly L.

    2016-08-01

    Studies of transuranic organometallic complexes provide a particularly valuable insight into covalent contributions to the metal-ligand bonding, in which the subtle differences between the transuranium actinide ions and their lighter lanthanide counterparts are of fundamental importance for the effective remediation of nuclear waste. Unlike the organometallic chemistry of uranium, which has focused strongly on UIII and has seen some spectacular advances, that of the transuranics is significantly technically more challenging and has remained dormant. In the case of neptunium, it is limited mainly to NpIV. Here we report the synthesis of three new NpIII organometallic compounds and the characterization of their molecular and electronic structures. These studies suggest that NpIII complexes could act as single-molecule magnets, and that the lower oxidation state of NpII is chemically accessible. In comparison with lanthanide analogues, significant d- and f-electron contributions to key NpIII orbitals are observed, which shows that fundamental neptunium organometallic chemistry can provide new insights into the behaviour of f-elements.

  5. Effect of the filtration of PbI2 solution for zinc oxide nanowire based perovskite solar cells

    Science.gov (United States)

    Mijanur Rahman, Md.; Uekawa, Naofumi; Shiba, Fumiyuki; Okawa, Yusuke; Sakai, Masatoshi; Yamamoto, Kazunuki; Kudo, Kazuhiro; Konishi, Takehisa

    2016-01-01

    Zinc oxide (ZnO) nanowires (NWs) are grown on fluorine-doped tin oxide (FTO) glass substrates via a simple reactive evaporation method without the presence of any catalysts or additives. The ZnO NWs show high crystallinity and preferential elongation along the c-axis of the hexagonal wurtzite crystal structure. The highly crystalline NWs as electron transporting layer have been used to fabricate the CH3NH3PbI3 perovskite solar cells and their photovoltaic performance were investigated. In this report, we studied the effect of filtration of PbI2-solution on surface morphology of CH3NH3PbI3 layer. Spin-coating of the filtered PbI2-solution leads to a better crystallization and relatively homogenous coverage of the CH3NH3PbI3 film, resulting in an enhancement of the solar cell efficiency compared to the cell fabricated using non-filtrated PbI2-solution. By synthesizing the CH3NH3PbI3 film using filtrated PbI2-solution, we achieved the best power conversion efficiency of 4.8% with a current density of 7.6 mA cm-2, the open circuit voltage of 0.79 V and fill factor of 0.63.

  6. Batch sorption and spectroscopic speciation studies of neptunium uptake by montmorillonite and corundum

    Science.gov (United States)

    Elo, O.; Müller, K.; Ikeda-Ohno, A.; Bok, F.; Scheinost, A. C.; Hölttä, P.; Huittinen, N.

    2017-02-01

    Detailed information on neptunium(V) speciation on montmorillonite and corundum surfaces was obtained by batch sorption and desorption studies combined with surface complexation modelling using the Diffuse Double-Layer (DDL) model, in situ time-resolved Attenuated Total Reflection Fourier-Transform Infrared (ATR FT-IR) and X-ray absorption (XAS) spectroscopies. The pH-dependent batch sorption studies and the spectroscopic investigations were conducted under carbonate-free conditions in 10 mM NaClO4 or 10 mM NaCl. Solid concentrations of 0.5 g/l and 5 g/l were used depending on the experiment. The neptunium(V) desorption from the two mineral surfaces was investigated at pH values ranging from 8 to 10, using the replenishment technique. Neptunium(V) was found to desorb from the mineral surface, however, the extent of desorption was dependent on the solution pH. The desorption of neptunium(V) was confirmed in the ATR FT-IR spectroscopic studies at pH 10, where all of the identified inner-sphere complexed neptunium(V), characterized by a vibrational band at 790 cm-1, was desorbed from both mineral surfaces upon flushing the mineral films with a blank electrolyte solution. In XAS investigations of neptunium(V) uptake by corundum, the obtained structural parameters confirm the formation of an inner-sphere complex adsorbed on the surface in a bidentate fashion. As the inner-sphere complexes found in the IR-studies are characterized by identical sorption bands on both corundum and montmorillonite, we tentatively assigned the neptunium(V) inner-sphere complex on montmorillonite to the same bidentate complex found on corundum in the XAS investigations. Finally, the obtained batch sorption and spectroscopic results were modelled with surface complexation modelling to explain the neptunium(V) speciation on montmorillonite over the entire investigated pH range. The modelling results show that cation exchange in the interlayer space as well as two pH-dependent surface complexes

  7. Separating nano graphene oxide from the residual strong-acid filtrate of the modified Hummers method with alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xuebing, E-mail: xuebinghu2010@gmail.com [Key Laboratory of Inorganic Membrane, Jingdezhen Ceramic Institute, Jingdezhen 333001 (China); Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 201800 (China); Yu, Yun, E-mail: yunyush@mail.sic.ac.cn [Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 201800 (China); Wang, Yongqing; Zhou, Jianer [Key Laboratory of Inorganic Membrane, Jingdezhen Ceramic Institute, Jingdezhen 333001 (China); Song, Lixin [Key Laboratory of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 201800 (China)

    2015-02-28

    Graphical abstract: By adding an alkaline (NaOH or KOH) solution, the unprecipitated nano graphene oxide undergoes fast aggregation from the residual strong-acid filtrate of the modified Hummers method and forms the stable floccules when the pH value of the filtrate is about 1.7. The acid–base interaction with the surface functional groups of the carbon layers plays a role in the aggregation of the unprecipitated nano graphene oxide. - Highlights: • The novel and high-efficient method for separating graphene oxide was showed. • Graphene oxide undergoes aggregation and forms the floccules when pH value is ∼1.7. • The acid–base interaction plays a role in the aggregation of graphene oxide. - Abstract: In the modified Hummers method for preparing graphene oxide, the yellow slurry can be obtained. After filtering through a quantitative filter paper, the strong-acid filtrate containing the unprecipitated nano graphene oxide was gained. The corresponding filtrate was added gradually with an alkaline (NaOH or KOH) solution at room temperature. The unprecipitated nano graphene oxide could undergo fast aggregation when the pH value of the filtrate was about 1.7 and formed the stable floccules. X-ray diffraction analysis shows the dominant peak of the floccules is about 11°, which accords to the peak of graphene oxide. Spectra of X-ray photoelectron spectroscopy confirm the presence in the floccules of an abundance of oxygen functional groups and the purified graphene oxide floccules can be obtained. Atomic force microscopy measurement shows the graphene oxide floccules consists of sheet-like objects, mostly containing only a few layers (about 5 layers). Zeta potential analysis demonstrates the surface charge of the graphene oxide is pH-sensitive and its isoelectric point is ∼1.7. The flocculation mechanism of graphene oxide ascribes to the acid–base interaction with the surface functional groups of the carbon layers.

  8. Concentration polarization phenomenon during the nanofiltration of multi-ionic solutions: influence of the filtrated solution and operating conditions.

    Science.gov (United States)

    Déon, Sébastien; Dutournié, Patrick; Fievet, Patrick; Limousy, Lionel; Bourseau, Patrick

    2013-05-01

    One of the major difficulties for the prediction of separation performances in the case of multi-ionic mixtures nanofiltration lies in the description of the concentration polarization phenomenon. Usual models available in literature do not take account of the polarization phenomenon or only describe it cursorily. Very few studies dedicated to the understanding and the specific description of the concentration polarization phenomenon are available in literature and a 2-D multi-ionic model describing the layer heterogeneity along the membrane length has never been proposed yet. The model used in the present work, called Pore and Polarization Transport Model (PPTM), allows an accurate description of the concentration polarization layer occurring during the filtration of multi-ionic solutions by taking account of the radial electromigrative transport in the layer, the turbulence, as well as the axial heterogeneity. In this context, the present paper aims at proposing a numerical investigation of the influence of operating conditions on the behavior of the polarization layer occurring at the membrane vicinity. The input parameters governing the transport through the membrane have been assessed in a previous study in the same experimental conditions so that only the polarization layer is investigated here. The proposed model which was previously validated on experimental observed rejection curves is then used to understand how operating conditions, such as applied pressure, feed flow-rate, or divalent ion proportion, govern the polarization phenomenon. For this purpose, concentration and thickness axial profiles along the membrane length and radial profiles within the polarization layer are investigated for various conditions. Finally, the impact of the type of divalent ion and the number of ions is also studied on various mixtures.

  9. Separating nano graphene oxide from the residual strong-acid filtrate of the modified Hummers method with alkaline solution

    Science.gov (United States)

    Hu, Xuebing; Yu, Yun; Wang, Yongqing; Zhou, Jianer; Song, Lixin

    2015-02-01

    In the modified Hummers method for preparing graphene oxide, the yellow slurry can be obtained. After filtering through a quantitative filter paper, the strong-acid filtrate containing the unprecipitated nano graphene oxide was gained. The corresponding filtrate was added gradually with an alkaline (NaOH or KOH) solution at room temperature. The unprecipitated nano graphene oxide could undergo fast aggregation when the pH value of the filtrate was about 1.7 and formed the stable floccules. X-ray diffraction analysis shows the dominant peak of the floccules is about 11°, which accords to the peak of graphene oxide. Spectra of X-ray photoelectron spectroscopy confirm the presence in the floccules of an abundance of oxygen functional groups and the purified graphene oxide floccules can be obtained. Atomic force microscopy measurement shows the graphene oxide floccules consists of sheet-like objects, mostly containing only a few layers (about 5 layers). Zeta potential analysis demonstrates the surface charge of the graphene oxide is pH-sensitive and its isoelectric point is ∼1.7. The flocculation mechanism of graphene oxide ascribes to the acid-base interaction with the surface functional groups of the carbon layers.

  10. 纳滤纯化低聚壳聚糖制备液%Nano-filtration purification of chitooligosaccharides solution

    Institute of Scientific and Technical Information of China (English)

    韩永萍; 林强

    2012-01-01

    The desalination and purification of chitooligosaccharides (COS) solution were investigated by using nano-filtration (NF). The optimal operation conditions of COS solution NF purified were obtained as follows: 35~40℃, 1.0 MPa operation pressure, COS solution diluted 2. 5 times as the feed solution of NF, and the optimal solution volume concentration factor of a period of the batch constant volume diafiltration process was 1. 5. Under these conditions, the monosaccharide and most of disaccharide and monovalent salts were removed from COS solution by NF, and the purity of high biological activity COS was up to 92%, at the same time the volume was condensed to a half of the initial feed solution.%对低聚壳聚糖制备液进行了纳滤纯化研究,试验确定纳滤的最佳操作条件为35~40℃、操作压力为1.0 MPa,制备液在纳滤之前还应稀释2.5倍,间歇恒容渗滤过程的每一运行周期的最优浓缩倍数为1.5倍.在该条件运行下,制备液中的单糖和大部分二糖及一价盐离子被脱出,高活性低聚壳聚糖的纯度高达92%,料液体积浓缩接近2倍.

  11. Sustainable Soil Washing: Shredded Card Filtration of Potentially Toxic Elements after Leaching from Soil Using Organic Acid Solutions.

    Directory of Open Access Journals (Sweden)

    Christopher Ash

    Full Text Available Shredded card (SC was assessed for use as a sorbent of potentially toxic elements (PTE carried from contaminated soil in various leachates (oxalic acid, formic acid, CaCl2, water. We further assessed SC for retention of PTE, using acidified water (pH 3.4. Vertical columns and a peristaltic pump were used to leach PTE from soils (O and A/B horizons before passing through SC. Sorption onto SC was studied by comparing leachates, and by monitoring total PTE contents on SC before and after leaching. SC buffers against acidic soil conditions that promote metals solubility; considerable increases in solution pH (+4.49 were observed. Greatest differences in solution PTE content after leaching with/without SC occurred for Pb. In oxalic acid, As, Cd, Pb showed a high level of sorption (25, 15, and 58x more of the respective PTE in leachates without SC. In formic acid, Pb sorption was highly efficient (219x more Pb in leachate without SC. In water, only Pb showed high sorption (191x more Pb in leachate without SC. In desorption experiments, release of PTE from SC varied according to the source of PTE (organic/mineral soil, and type of solvent used. Arsenic was the PTE most readily leached in desorption experiments. Low As sorption from water was followed by fast release (70% As released from SC. A high rate of Cd sorption from organic acid solutions was followed by strong retention (~12% Cd desorption. SC also retained Pb after sorption from water, with subsequent losses of ≤8.5% of total bound Pb. The proposed use of this material is for the filtration of PTE from extract solution following soil washing. Low-molecular-mass organic acids offer a less destructive, biodegradable alternative to strong inorganic acids for soil washing.

  12. Selective removal/recovery of RCRA metals from waste and process solutions using polymer filtration{trademark} technology

    Energy Technology Data Exchange (ETDEWEB)

    Smith, B.F. [Los Alamos National Lab., NM (United States)

    1997-10-01

    Resource Conservation and Recovery Act (RCRA) metals are found in a number of process and waste streams at many DOE, U.S. Department of Defense, and industrial facilities. RCRA metals consist principally of chromium, mercury, cadmium, lead, and silver. Arsenic and selenium, which form oxyanions, are also considered RCRA elements. Discharge limits for each of these metals are based on toxicity and dictated by state and federal regulations (e.g., drinking water, RCRA, etc.). RCRA metals are used in many current operations, are generated in decontamination and decommissioning (D&D) operations, and are also present in old process wastes that require treatment and stabilization. These metals can exist in solutions, as part of sludges, or as contaminants on soils or solid surfaces, as individual metals or as mixtures with other metals, mixtures with radioactive metals such as actinides (defined as mixed waste), or as mixtures with a variety of inert metals such as calcium and sodium. The authors have successfully completed a preliminary proof-of-principle evaluation of Polymer Filtration{trademark} (PF) technology for the dissolution of metallic mercury and have also shown that they can remove and concentrate RCRA metals from dilute solutions for a variety of aqueous solution types using PF technology. Another application successfully demonstrated is the dilute metal removal of americium and plutonium from process streams. This application was used to remove the total alpha contamination to below 30 pCi/L for the wastewater treatment plant at TA-50 at Los Alamos National Laboratory (LANL) and from nitric acid distillate in the acid recovery process at TA-55, the Plutonium Facility at LANL (ESP-CP TTP AL16C322). This project will develop and optimize the PF technology for specific DOE process streams containing RCRA metals and coordinate it with the needs of the commercial sector to ensure that technology transfer occurs.

  13. Application of Solution-blown 20-50 nm Nanofibers in Filtration of Nanoparticles: The Efficient van der Waals Collectors

    Science.gov (United States)

    Sinha-Ray, Sumit; Sinha-Ray, Suman; Yarin, Alexander; Pourdeyhimi, Behnam

    2015-11-01

    Filtration efficiency of commercially available filter media with fiber/pore sizes on the scale of 10 μm can be dramatically increased by adding a layer of ultrafine supersonically-blown 20-50 nm nanofibers. Different commercial filters were modified with (i) electrospun nanofibers alone, (ii) solution-blown 20-50 nm alone, and (iii) the dual coating with electrospun nanofibers deposited first and the solution-blown 20-50 nm nanofibers deposited on top of them. Detailed observations of nanoparticle removal revealed that the above-mentioned modified filters, especially those with the dual nanofiber coating with the 20-50 nm nanofibers deposited on top, are the most effective in removing the below-200 nm Cu nanoparticles/clusters from aqueous suspensions, in particular at the lowest concentrations of 0.2-0.5 ppm. The theory developed in the present work dealing with convective transport of nanoparticles in the fluid flow along with diffusion of nanoparticles and the van der Waals attraction explains and describes how the smallest solution-blown nanofibers introduce a novel physical mechanism of nanoparticle interception (the attractive van der Waals forces) and become significantly more efficient collectors compared to the larger electrospun nanofibers. The theory also elucidates the morphology of the nanoparticle clusters being accumulated at the smallest nanofiber surfaces, including the clusters growing at the windward side, or in some cases also on the leeward side of a nanofiber. This work is supported by the Nonwovens Cooperative Research Center (NCRC), grant No. 12-144SB.

  14. Filtration Fundamentals.

    Science.gov (United States)

    Ward, Ken; Hunsaker, Scot

    1997-01-01

    Examines how choice of commercial swimming-pool filtration systems is driven by the project-specific needs of the pools. Also highlighted are definitions of specific terms used when discussing filtration systems. Questions that pool designers can answer to make filtration-system purchasing decisions are listed. (GR)

  15. Neptunium Binding Kinetics with Arsenazo(III)

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Leigh R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Johnson, Aaron T. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mezyk, Stephen P. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-08-01

    This document has been prepared to meet FCR&D level 2 milestone M2FT-14IN0304021, “Report on the results of actinide binding kinetics with aqueous phase complexants” This work was carried out under the auspices of the Thermodynamics and Kinetics of Advanced Separations Systems FCR&D work package. The report details kinetics experiments that were performed to measure rates of aqueous phase complexation for pentavalent neptunium with the chromotropic dye Arsenazo III (AAIII). The studies performed were designed to determine how pH, ionic strength and AAIII concentration may affect the rate of the reaction. A brief comparison with hexavalent neptunium is also made. It was identified that as pH was increased the rate of reaction also increased, however increasing the ionic strength and concentration of AAIII had the opposite effect. Interestingly, the rate of reaction of Np(VI) with AAIII was found to be slower than that of the Np(V) reaction.

  16. Speciation of neptunium during migration in clay rock; Speziation von Neptunium bei der Migration in Tongestein

    Energy Technology Data Exchange (ETDEWEB)

    Froehlich, Daniel

    2011-12-15

    The present work was performed within a fellowship of the interdisciplinary research training group 826 ''trace analysis of elemental species: method development and application'' funded by the German Research Foundation (DFG) and the federal state Rheinland-Pfalz. Aim of this work was to gain new knowledge of the interaction between neptunium and natural clay rock with respect to the disposal of high-level nuclear waste in deep geological formations. The isotope {sup 237}Np with its long half-life of more than two million years will be one of main contributors to the radiotoxicity of the radioactive waste material after storage times of more than 1000 years. In aqueous solution under environmental relevant conditions Np can exist in the oxidation states +IV and +V. Due to its high solubility and higher mobility Np(V) is the much more hazardous species compared to Np(IV). Opalinus Clay (OPA) from Mont Terri, Switzerland, was used as a natural reference material in the migration studies. The focus of this work was on speciation of Np on the mineral surface by synchrotron based X-ray absorption spectroscopy (EXAFS/XANES). The interaction between Np(V) and OPA was studied in batch sorption and diffusion experiments in dependence of various experimental parameters (e.g. pH, temperature, background electrolyte, effect of humic acid, concurrence with U(VI), aerobic/anaerobic conditions). The investigation of Np speciation was performed on two types of samples. Powder samples from batch experiments were prepared under aerobic and anaerobic conditions and measured by EXAFS spectroscopy. Diffusion samples and OPA thin sections contacted with Np(V) were analyzed by locally resolved μ-XANES measurements on enrichments of Np. A combination with μ-XRF (X-ray fluorescence) mapping and μ-XRD (X-ray diffraction) measurements provided further information about the spatial distribution of Np and other elements contained in OPA as well as crystalline mineral

  17. Study of speciation and size fractionation of trace element between soil solution, bog, river and lake within a boreal watershed (North Karelia, NW Russia) using fractional filtration

    Science.gov (United States)

    Ilina, Svetlana M.; Lapitsky, Sergey A.; Alekhin, Yuriy V.; Pokrovsky, Oleg S.; Viers, Jerome

    2010-05-01

    This work is aimed at studying the evolution of migration forms of true dissolved compounds and colloidal entities using an integrated approach of molecular mass distribution and differences in the association of trace elements (TE) with organic matter (OM) or Fe colloids in the system soil water-bog-river-lake. Characterization of TE speciation with colloids during TE migration from the site of colloids origin (bog and soil solutions) towards the transit zone (river) and finally to the deposition, accumulation or transformation zone (lake) is a main fundamental task of this problem. The objects of study include a small stream watershed Vostochniy and the river Palayoki (North Karelia, Russia). The water samplings were performed in July and August 2008 and 2009 and included soil solution, nourishing bog, the middle part of the brook originated from the swamp, the mouth of the brook and the lake Zipringa. We sampled large volumes (50 - 100 liters), and we applied, directly in the in-field-installed "clean laboratory" the sequential frontal filtration and ultrafiltration of samples through the filters of progressively decreasing poresize 100, 20, 10, 5, 0.8, 0.4, 0.2 and 0.1 microns; 100 kDa (0.0065 micron), 10 kDa (0.003 micron) and 1 kDa (0.0014 micron). This allowed separation of organic matter, coarse and fine particulate matter and colloids. All filtrates and selected retentates were analyzed for a wide range of macro-and micronutrients using ICP-MS. In filtrates of the river water, a significant decrease of iron concentration occurred in the range of 5 micron to 0.22 micron and from 100 kDa to 1 kDa. For alkali and alkaline earth elements (Mg, K, Ca), as well as for Cu, Ni, Cr the concentrations changed after passing through the 10 kDa membrane. Na concentration remains constant in all filtrates. The filtrates of the soil solution are characterized by a significant decreases in Na, K, after 0.1 micron, Ca, Cu in the range of 0.22 micron - 100 kDa and Mg, Ni in

  18. Spectrophotometric study of neptunium (VI) complexation by nitrate ions; Etude par spectrophotometrie de la complexation du neptunium au degre d'oxydation (VI) par les ions nitrates

    Energy Technology Data Exchange (ETDEWEB)

    Pochon, P. [CEA/VALRHO - site de Marcoule, Dept. de Recherche en Retraitement et en Vitrification (DRRV), 30 - Marcoule (France)]|[Conservatoire National des Arts et Metiers (CNAM), 75 - Paris (France)]|[Centre Regional Associe de Lyon, 69 (France)

    2000-07-01

    Neptunium(VI) complexation by nitrate ions was investigated by visible and near-infrared spectrophotometry, a technique suitable for observing the appearance and evolution of the species in solution. In the absence of reference spectra for Np(VI) nitrate- complexes, mathematical (factor analysis) tools were used to interpret the spectra. These chemo-metric techniques were first tested and validated on a simpler chemical system: Np(VI)complexation by the SiW{sub 11}O{sub 39}{sup 8-} anion. The test media used to investigate Np(VI) nitrate- complexes generally contain nitrate and perchlorate salts at high concentrations (high ionic strength). Media effects arising from the presence of cations, acidity or the perchlorate ion concentration are therefore significant, and no doubt account for the scattered values of the complexation constants published in the literature. The evolution of the neptunium spectra according to the parameters of the reaction medium illustrated these effects and allowed them to be quantified by a global 'perturbation constant'. In order to minimize the spectrum modifications due to media effects, the neptunium nitrate-complexes were studied at constant ionic strength in weak acidic media (2 mol.kg{sup -1}{sub H2O}) in the presence of sodium salts. The bulk formation constants and the spectrum of the NpO{sub 2}(NO{sub 3}){sup +} complex were determined for ionic strength values of 2.2, 4, 6 and 8 mol.kg{sup -1}{sub H2O}. The constants remained on the same order of magnitude regardless of the ionic strength; the thermodynamic constant {beta}{sub 1}{sup 0} determined from them according to specific interaction theory is thus probably of little significance. Conversely, the bulk constants can be corrected for the effects of the perchlorate ions by taking the global 'perturbation constant' into account. (author)

  19. Shortening filtrations

    Institute of Scientific and Technical Information of China (English)

    ENOCHS Edgar E.

    2012-01-01

    Let C be a set of modules.We argue that there is an ordinal κ such that if a module has a filtration by modules in C,then it has a filtration of length κ by direct sums of modules in C.As an application we give another way to prove a result of Saorín and (S)(t)oví(c)ek and of (S)(t)oví(c)ek.

  20. Speciation of neptunium during sorption and diffusion in natural clay

    Science.gov (United States)

    Reich, T.; Amayri, S.; Bӧrner, P. J. B.; Drebert, J.; Frӧhlich, D. R.; Grolimund, D.; Kaplan, U.

    2016-05-01

    In argillaceous rocks, which are considered as a potential host rock for nuclear waste repositories, sorption and diffusion processes govern the migration behaviour of actinides like neptunium. For the safety analysis of such a repository, a molecular-level understanding of the transport and retardation phenomena of radioactive contaminants in the host rock is mandatory. The speciation of Np during sorption and diffusion in Opalinus Clay was studied at near neutral pH using a combination of spatially resolved synchrotron radiation techniques. During the sorption and diffusion experiments, the interaction of 8 μM Np(V) solutions with the clay lead to the formation of spots at the clay-water interface with increased Np concentrations as determined by μ-XRF. Several of these spots are correlated with areas of increased Fe concentration. Np L3-edge μ-XANES spectra revealed that up to 85% of the initial Np(V) was reduced to Np(IV). Pyrite could be identified by μ-XRD as a redox-active mineral phase responsible for the formation of Np(IV). The analysis of the diffusion profile within the clay matrix after an in-diffusion experiment for two months showed that Np(V) is progressively reduced with diffusion distance, i.e. Np(IV) amounted to ≈12% and ≈26% at 30 μm and 525 μm, respectively.

  1. Separation Method of Uranium and Plutonium From Large Amount of Neptunium

    Institute of Scientific and Technical Information of China (English)

    SU; Yu-lan; JIN; Hua; YING; Zhe-cong; ZHAO; Sheng-yang

    2013-01-01

    Uranium and plutonium are limited strictly in the neptunium product.To eliminate the influence of neptunium matrix on determination of uranium and plutonium,a new separation method of uranium and plutonium from large amount of neptunium by TEVA column has been developed,which is illustrated in Fig.1.

  2. Sensitive redox speciation of neptunium by CE-ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Stoebener, Nils; Amayri, Samer; Gehl, Aaron; Kaplan, Ugras; Malecha, Kurtis; Reich, Tobias [Johannes Gutenberg-Universitaet Mainz, Institute of Nuclear Chemistry, Mainz (Germany)

    2012-11-15

    Capillary electrophoresis (CE) was used to separate the neptunium oxidation states Np(IV) and Np(V), which are the only oxidation states of Np that are stable under environmental conditions. The CE setup was coupled to an inductively coupled plasma mass spectrometer (Agilent 7500ce) using a Mira Mist CE nebulizer and a Scott-type spray chamber. The combination of the separation capacity of CE with the detection sensitivity of inductively coupled plasma mass spectrometry (ICP-MS) allows identification and quantification of Np(IV) and Np(V) at the trace levels expected in the far field of a nuclear waste repository. Limits of detection of 1 x 10{sup -9} and 5 x 10{sup -10} mol L{sup -1} for Np(IV) and Np(V), respectively, were achieved, with a linear range from 10{sup -9} to 10{sup -6} mol L{sup -1}. The method was applied to study the redox speciation of the Np remaining in solution after interaction of 5 x 10{sup -7} mol L{sup -1} Np(V) with Opalinus Clay. Under mildly oxidizing conditions, a Np sorption of 31% was found, with all the Np remaining in solution being Np(V). A second sorption experiment performed in the presence of Fe{sup 2+} led to complete sorption of the Np onto the clay. After desorption with HClO{sub 4}, a mixture of Np(IV) and Np(V) was found in solution by CE-ICP-MS, indicating that some of the sorbed Np had been reduced to Np(IV) by Fe{sup 2+}. (orig.)

  3. 一般非线性渗流方程广义解的存在唯一性与Blow-up%Existence,Uniqueness and Blow-up of Generalized Solutions to General Nonlinear Filtration Equations

    Institute of Scientific and Technical Information of China (English)

    霍振宏; 李海峰

    2008-01-01

    In this paper,we consider nonnegative solutions to Cauchy problem for the general nonlinear filtration equations ut-Dj(aij(x,t,u)Diφ(u))+bi(t,u)Diu+C(x,t,u)=0,and obtain the existence,uniqueness and blow-up in finite time of these solutions under some structure conditions.

  4. GSPEL - Air Filtration Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Evaluation capabilities for air filtration devices The Air Filtration Lab provides testing of air filtration devices to demonstrate and validate new or legacy system...

  5. Polymeric microspheres with N-methyl-D-glucamine ligands for boron removal from water solution by adsorption-membrane filtration process.

    Science.gov (United States)

    Wolska, Joanna; Bryjak, Marek; Kabay, Nalan

    2010-08-01

    Polymeric microspheres with N-methyl-D-glucamine (NMDG) ligands have been tested in the adsorption-membrane filtration process for boron removal from aqueous solutions. The chelating resins were synthesized by reacting NMDG with the vinylbenzyl chloride-styrene-1,4-divinylbenzene (VBC/S/DVB) copolymer at the reflux temperature and in the microwave reactor. VBC/S/DVB spheres with a gel structure that contained 6 wt% DVB were obtained by membrane emulsification followed by suspension polymerization. By selecting the optimal emulsification and polymerization parameters, it was possible to obtain 25-microm-diameter particles with a narrow size distribution. Resins obtained by microwave modification showed the higher boron adsorption capacity.

  6. Bio-sorption of neptunium(V) by Pseudomonas fluorescens

    Energy Technology Data Exchange (ETDEWEB)

    Songkasiri, W. [Dept. of Civil Engineering, Northwestern Univ., Evanston, IL (United States); Chemical Technology Div., Argonne National Lab., Argonne, IL (United States); Reed, D.T. [Chemical Technology Div., Argonne National Lab., Argonne, IL (United States); Rittmann, B.E. [Dept. of Civil Engineering, Northwestern Univ., Evanston, IL (United States)

    2002-07-01

    The bio-sorption of neptunyl (NpO{sub 2}{sup +}) by Pseudomonas fluorescens was investigated. The overall goals of this research are to identify key interactions between neptunium and soil bacteria and to model these effects under subsurface-related conditions. Neptunyl, which is generally thought to be non-sorptive, was significantly sorbed under all conditions studied. At initial neptunyl concentrations of 4.75 {mu}M and pH = 7, as much as 85% of the neptunium was sorbed under aerobic conditions. Kinetic studies show that neptunyl was sorbed rapidly within the first 15 minutes. The extent of sorption also increased with pH. In all cases, the sorbed neptunium was shown to be NpO{sub 2}{sup +} by X-ray absorption near edged spectroscopy (XANES) analysis, confirming that there was no reduction to Np(IV) under the conditions of our experiment. The sorption data were modeled using Langmuir and Freundlich isotherms. A comparison of the two approaches showed a significantly better fit for the Freundlich isotherm, and the Freundlich parameter values suggest interactions between sorbed NpO{sub 2}{sup +} molecules. These data show that bio-sorption, even for neptunyl, has a significant role in defining the speciation of neptunium and, hence, its overall mobility in the subsurface. (orig.)

  7. Separation Method of Neptunium From Large Amount of Plutonium

    Institute of Scientific and Technical Information of China (English)

    JIN; Hua; SU; Yu-lan; YING; Zhe-cong; ZHAO; Sheng-yang

    2013-01-01

    A new separation method of neptunium from large amount of plutonium by TEVA column has been developed.A series of influence factors are studied such as resin’s types,valence adjusting of Np and Pu,extraction and elution behavior of Np on TEVA resin.According to above works,a separation procedure is recommended as follows:1)Adjusting the

  8. Influence of nitrate ions on the physicochemical behavior of neptunium; Etude de la complexation du neptunium+6 par les ions nitrate: approche chimiometrique

    Energy Technology Data Exchange (ETDEWEB)

    Pochon, P.; Moisy, Ph.; Blanc, P. [CEA Valrho, (DCC/DRRV/SEMP), 30 - Marcoule (France)

    2000-07-01

    The aim of this work was to acquire data on Np(VI) nitrate-complexes, particularly concerning their stability in nitric acid media, to gain a closer understanding of neptunium behavior in the PUREX process used for spent nuclear fuel reprocessing. Due to their very poor stability and the importance of physico-chemical mechanisms in concentrated solutions (media effects), the published data concerning these complexes are subject to considerable debate. A visible and near-infrared spectrophotometric study of Np(VI) nitrate-complexes was therefore undertaken to observe and quantify the influence of nitrate ions on the physicochemical behavior of neptunium, and to estimate the magnitude of the media effects in order to propose a constant of complexation by nitrate ions that is independent of the composition of the reaction medium (i.e. a thermodynamic constant). In the absence of reliable spectra for neptunium in nitric acid media, the spectrophotometric data were processed by principal components analysis and factor analysis mathematical method. The ionic strength of the solutions was adjusted by adding perchlorate salts (perchlorate ions were considered to have little or no complexing properties). The influence of the type of cation (H{sup +}, Li{sup +}, Na{sup +}, Ba{sup 2+}, Mg{sup 2+}) and the perchlorate ion concentration was observed on the neptunium(VI) spectra in nitric and perchloric media. In the presence of nitrate ions, the spectrum modifications in case of substitution of one cation by another were comparable to those observed for major nitrate ion concentration variations. Similarly, the extent of the spectrum modifications for the same nitrate ion concentration variation depended on the proton concentration. Weak spectrum modifications were also observed when the perchlorate ion concentration varied. They were quantified by a 'perturbation constant' {beta}* calculated in the same way as a complexation constant ({beta}* = 0.023 in the molal

  9. 膜滤工艺对安神补脑液药效的影响%Influence of Membrane Filtration on Efficacy of Anshen Bunao Solutions

    Institute of Scientific and Technical Information of China (English)

    许招懂; 吴清和; 蒋莉娟; 黄萍; 黎志坚; 翟小玲; 徐娟

    2011-01-01

    Objective To study the influence of membrane filtration on the efficacy of Anshen Bunao Solutions. Methods Spontaneous activities of mice, sleeping time in mice induced by threshold dose of sodium pentobarbital, induced dormancy in mice at subliminal dose of sodium pentobarbital, and drug-induced anticonvulsion in mice were observed to evaluate the sedative and hypnotic effect of Anshen Bunao Solutions. Memory acquirement deficits in mice (scopolamine model), memory consolidation deficits in mice (sodium nitrite model) and memory representation disorder in mice(ethanol model) were adopted to study the effect of Anshen Bunao Solutions on the improvement of memory. Experiments of hypoxia under ordinary pressure in mice and decapitation hypoxia in mice, and swimming test were used to estimate the anti-hypoxia and anti-fatigue effect of Anshen Bunao Solutions. Results Anshen Bunao Solutions processed with membrane filtration could reduce spontaneous activities of mice, prolong sodium pentobarbital-induced sleeping time in mice, increase the amount of induced dormancy mice at subliminal dose of sodium pentobarbital, improve memory acquirement deficits and memory representation disorder in mice, and prolong the survival time of hypoxic mice under ordinary pressure and decapitation hypoxic mice. Conclusion Anshen Bunao Solutions processed with membrane filtration exerts certain sedative and hypnotic effect, memory improvement and anti-hypoxia action.%目的 研究膜滤工艺对安神补脑液有效性的影响.方法用小鼠自主活动、戊巴比妥钠阈剂量所致小鼠睡眠时间实验、戊巴比妥钠阁下催眠剂量试验和药物致小鼠惊厥实验,观察安神补脑液的镇静催眠作用;选择小鼠记忆获得障碍模型、小鼠记忆巩固障碍模型和小鼠记忆再现障碍模型,观察安神补脑液对记忆功能的改善作用;用小鼠常压缺氧、小鼠断头缺氧及游泳实验观察安神补脑液的抗缺氧、抗疲劳作用.

  10. Self-cleaning Metal Organic Framework (MOF) based ultra filtration membranes - A solution to bio-fouling in membrane separation processes

    Science.gov (United States)

    Prince, J. A.; Bhuvana, S.; Anbharasi, V.; Ayyanar, N.; Boodhoo, K. V. K.; Singh, G.

    2014-10-01

    Bio-fouling is a serious problem in many membrane-based separation processes for water and wastewater treatment. Current state of the art methods to overcome this are to modify the membranes with either hydrophilic additives or with an antibacterial compound. In this study, we propose and practise a novel concept to prevent bio-fouling by developing a killing and self-cleaning membrane surface incorporating antibacterial silver nanoparticles and highly hydrophilic negatively charged carboxylic and amine functional groups. The innovative surface chemistry helps to reduce the contact angle of the novel membrane by at least a 48% and increase the pure water flux by 39.4% compared to the control membrane. The flux drop for the novel membrane is also lower (16.3% of the initial flux) than the control membrane (55.3% of the initial flux) during the long term experiments with protein solution. Moreover, the novel membrane continues to exhibit inhibition to microbes even after 1320 min of protein filtration. Synthesis of self-cleaning ultrafiltration membrane with long lasting properties opens up a viable solution for bio-fouling in ultrafiltration application for wastewater purification.

  11. Effect of Magnetic Field on Crossflow Memebrane Filtration of Electrolytical Solution%磁场在膜过滤电解质溶液体系中的应用

    Institute of Scientific and Technical Information of China (English)

    舒莉; 顾春雷; 邢卫红

    2013-01-01

    Magnetic field was applied in the filtration process of electrolytical solution system by ceramic membrane. The effect of several factors on the ion permeation ratio were investigated. For sodium chloride solution, the permeate flux were not changed with magnetic filed action, but the ion permeate ratio increased in filtration process. The magnetic pole direction and increasing cross-flow velocity didn' t influence the separation performance. The effect of magnetic field on the sodium chloride filtration increased with increasing magnetic field strength, solution concentration and decreasing membrane pore size. The ion permeate ratio of calcium chloride solution and sodium sulfate solution also increased under magnetic field. The simulated suspension consisting of calcium carbonate particles and sodium chloride solution were ion cleaning of particle surface by membrane filtration. The magnetic field assisting filtration could increase the rate of cleaning ion especially for that of the lower particle concentration.%将磁场作用于陶瓷膜过滤电解质溶液体系,改变水溶液中离子的水合状态.磁场对膜过滤通量没有影响,但可以提高过滤电解质溶液时的离子透过率.磁场作用方向和膜面流速的改变对离子透过率的影响不明显.增大磁场强度、提高电解质溶液的浓度,减小膜孔径时,磁场对过滤过程的影响作用更明显.采用膜过滤的方法清洗颗粒表面的离子时,加入磁场的作用可以提高离子洗涤的速率,且颗粒浓度比较低时,清洗速度更快.

  12. Neptunium and plutonium complexes with a sterically encumbered triamidoamine (TREN) scaffold.

    Science.gov (United States)

    Brown, Jessie L; Gaunt, Andrew J; King, David M; Liddle, Stephen T; Reilly, Sean D; Scott, Brian L; Wooles, Ashley J

    2016-04-07

    The syntheses and characterisation of isostructural neptunium(iv) and plutonium(iv) complexes [An(IV)(TREN(TIPS))(Cl)] [An = Np, Pu; TREN(TIPS) = {N(CH2CH2NSiPr(i)3)3}(3-)] are reported, along with the demonstration that they are likely reduced to the corresponding neptunium(iii) and plutonium(iii) products [An(III)(TREN(TIPS))]; this chemistry provides new platforms from which to target a plethora of unprecedented molecular functionalities in transuranic chemistry and the neptunium(iv) molecule is the first structurally characterised neptunium(iv)-amide complex.

  13. Mineralogic controls on aqueous neptunium(V) concentrations in silicate systems

    Energy Technology Data Exchange (ETDEWEB)

    Alessi, Daniel S., E-mail: daniel.alessi@epfl.ch [Department of Civil Engineering and Geological Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556 (United States); Szymanowski, Jennifer E.S. [Department of Civil Engineering and Geological Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556 (United States); Forbes, Tori Z. [Department of Civil Engineering and Geological Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556 (United States); Department of Chemistry, University of Iowa, Room E331 CB, Iowa City, IA 52242 (United States); Quicksall, Andrew N. [Department of Civil Engineering and Geological Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556 (United States); Department of Civil and Environmental Engineering, Southern Methodist University, P.O. Box 750340, Dallas, TX 75275 (United States); Sigmon, Ginger E.; Burns, Peter C.; Fein, Jeremy B. [Department of Civil Engineering and Geological Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, IN 46556 (United States)

    2013-02-15

    The presence of radioactive neptunium in commercially spent nuclear fuel is problematic due to its mobility in environmental systems upon oxidation to the pentavalent state. As uranium is the major component of spent fuel, incorporation of neptunium into resulting U(VI) mineral phases would potentially influence its release into environmental systems. Alternatively, aqueous neptunium concentrations may be buffered by solid phase Np{sub 2}O{sub 5}. In this study, we investigate both of these controls on aqueous neptunium(V) concentrations. We synthesize two uranyl silicates, soddyite, (UO{sub 2}){sub 2}SiO{sub 4}·2H{sub 2}O, and boltwoodite, (K, Na)(UO{sub 2})(SiO{sub 3}OH)·1.5H{sub 2}O, each in the presence of two concentrations of aqueous Np(V). Electron microscopy and electron diffraction analyses of the synthesized phases show that while significant neptunyl incorporation occurred into soddyite, the Np(V) in the boltwoodite systems largely precipitated as a secondary phase, Np{sub 2}O{sub 5(s)}. The release of Np(V) from each system into aqueous solution was measured for several days, until steady-state concentrations were achieved. Using existing solubility constants (K{sub sp}) for pure soddyite and boltwoodite, we compared predicted equilibrium aqueous U(VI) concentrations with the U(VI) concentrations released in the solubility experiments. Our experiments reveal that Np(V) incorporation into soddyite increases the concentration of aqueous U in equilibrium with the solid phase, perhaps via the formation of a metastable phase. In the mixed boltwoodite – Np{sub 2}O{sub 5(s)} system, the measured aqueous U(VI) activities are consistent with those predicted to be in equilibrium with boltwoodite under the experimental conditions, a result that is consistent with our conclusion that little Np(V) incorporation occurred into the boltwoodite. In the boltwoodite systems, the measured Np concentrations are likely controlled by the presence of Np{sub 2}O{sub 5

  14. Syntheses of neptunium trichloride and measurements of its melting temperature

    Science.gov (United States)

    Hayashi, Hirokazu; Takano, Masahide; Kurata, Masaki; Minato, Kazuo

    2013-09-01

    Neptunium trichloride (NpCl3) of high purity was synthesized by the solid state reaction of neptunium nitride with cadmium chloride. Lattice parameters of hexagonal NpCl3 were determined from the powder X-ray diffraction pattern to be a = 0.7428 ± 0.0001 nm and c = 0.4262 ± 0.0003 nm, which fairly agree with the reported values. The melting temperature of NpCl3 was measured on a sample of about 1 mg, hermetically encapsulated in a gold crucible with a differential thermal analyzer. The value determined was 1070 ± 3 K which is close to the recommended value (1075 ± 30 K) derived from the mean value of the melting temperature of UCl3 and of PuCl3.

  15. SEPARATION OF NEPTUNIUM FROM PLUTONIUM BY CHLORINATION AND SUBLIMATION

    Science.gov (United States)

    Fried, S.M.

    1958-11-18

    A process is described for separating neptunium from plutonium. The method consists in chlorinating a mixture of the oxides of Np and Pu by contacting the mixture with carbon tetrachloride at about 500 icient laborato C. ln this manner the Np is converted to the tetrachlorlde and the Pu converted to the trichloride. Since NpCl/sub 4/ is more latile than PuCl/sub 3/, the separation ls effected by vaporing sad subsequently condenslng the NpCl/sub 4/.

  16. GSPEL - Air Filtration Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Evaluation capabilities for air filtration devicesThe Air Filtration Lab provides testing of air filtration devices to demonstrate and validate new or legacy system...

  17. Estimated glomerular filtration rate is a poor predictor of the concentration of middle molecular weight uremic solutes in chronic kidney disease.

    Directory of Open Access Journals (Sweden)

    Nathalie Neirynck

    Full Text Available BACKGROUND: Uremic solute concentration increases as Glomerular Filtration Rate (GFR declines. Weak associations were demonstrated between estimated GFR (eGFR and the concentrations of several small water-soluble and protein-bound uremic solutes (MW500 Da. MATERIALS AND METHODS: In 95 CKD-patients (CKD-stage 2-5 not on dialysis, associations between different eGFR-formulae (creatinine, Cystatin C-based or both and the natural logarithm of the concentration of several LMWP's were analyzed: i.e. parathyroid hormone (PTH, Cystatin C (CystC, interleukin-6 (IL-6, tumor necrosis factor-alpha (TNF-α, leptin, retinol binding protein (RbP, immunoglobin light chains kappa and lambda (Ig-κ and Ig-λ, beta-2-microglobulin (β(2M, myoglobin and fibroblast growth factor-23 (FGF-23. RESULTS: The regression coefficients (R(2 between eGFR, based on the CKD-EPI-Crea-CystC-formula as reference, and the examined LMWP's could be divided into three groups. Most of the LMWP's associated weakly (R(2 0.7. Almost identical R(2-values were found per LMWP for all eGFR-formulae, with exception of CystC and β(2M which showed weaker associations with creatinine-based than with CystC-based eGFR. CONCLUSION: The association between eGFR and the concentration of several LMWP's is inconsistent, with in general low R(2-values. Thus, the use of eGFR to evaluate kidney function does not reflect the concentration of several LMWP's with proven toxic impact in CKD.

  18. Comparison of sample preparation methods for reliable plutonium and neptunium urinalysis using automatic extraction chromatography

    DEFF Research Database (Denmark)

    Qiao, Jixin; Xu, Yihong; Hou, Xiaolin

    2014-01-01

    of plutonium and neptunium associated with organic compounds in real urine assays. In this work, different protocols for decomposing organic matter in urine were investigated, of which potassium persulfate (K2S2O8) treatment provided the highest chemical yield of neptunium in the iron hydroxide co...

  19. Rapid sample processing for intracellular metabolite studies in Penicillium ochrochloron CBS 123.824: the FiltRes-device combines cold filtration of methanol quenched biomass with resuspension in extraction solution.

    Science.gov (United States)

    Vrabl, Pamela; Artmann, Desiree J; Schinagl, Christoph W; Burgstaller, Wolfgang

    2016-01-01

    Many issues concerning sample processing for intracellular metabolite studies in filamentous fungi still need to be solved, e.g. how to reduce the contact time of the biomass to the quenching solution in order to minimize metabolite leakage. Since the required time to separate the biomass from the quenching solution determines the contact time, speeding up this step is thus of utmost interest. Recently, separation approaches based on cold-filtration were introduced as promising alternative to cold-centrifugation, which exhibit considerably reduced contact times. In previous works we were unable to obtain a compact pellet from cold methanol quenched samples of the filamentous fungus Penicillium ochrochloron CBS 123.824 via centrifugation. Therefore our aim was to establish for this organism a separation technique based on cold-filtration to determine intracellular levels of a selected set of nucleotides. We developed a cold-filtration based technique as part of our effort to revise the entire sample processing method and analytical procedure. The Filtration-Resuspension (FiltRes) device combined in a single apparatus (1) a rapid cold-filtration and (2) a rapid resuspension of the biomass in hot extraction solution. Unique to this is the injection of the extraction solution from below the membrane filter (FiltRes-principle). This caused the mycelial cake to detach completely from the filter membrane and to float upwards so that the biomass could easily be transferred into preheated tubes for metabolite extraction. The total contact time of glucose-limited chemostat mycelium to the quenching solution could be reduced to 15.7 ± 2.5 s, whereby each washing step added another 10-15 s. We evaluated critical steps like filtration time, temperature profile, reproducibility of results, and using the energy charge (EC) as a criterion, effectiveness of enzyme destruction during the transition in sample temperature from cold to hot. As control we used total broth samples

  20. Filtration and compression of organic materials

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Keiding, Kristian

    The conventional filtration theory has been based on filtrations of incompressible particles such as anatase, kaolin and clay. The filtration models have later been used for organic slurries but can often not explain the observed experimental data. At constant pressure, the filtrate volume does...... not increase in proportion with square root time when e.g. sewage sludge and manure are filtered. Different explanations have been suggested. However, organic slurries are complex mixtures and it is therefore difficult to evaluate the suggested explanations and develops new models. One possible solution...

  1. A contribution to the study of thorium and neptunium (IV) complexes in acidic phosphoric media; Contribution a l`etude des complexes de thorium et de neptunium (IV) en milieux phosphoriques acides

    Energy Technology Data Exchange (ETDEWEB)

    Ghafar, M.

    1995-11-30

    The thorium and neptunium (IV) phosphate complexes formation in acidic media has been investigated, essentially at the indicator`s level with {sup 227} Th, {sup 234} Th, {sup 235} Np and {sup 239} Np. Solvent extraction, a commonly used method for determining stability constants in solutions, was used with HDEHP in toluene. In order to get a better understanding of inorganic transparent gels formation in phosphoric aqueous solutions, the effect of the thorium concentration is also studied. Specific experimental conditions have been chosen in order to avoid the formation of chelate and hydrolysis in the aqueous solution. The equilibrium constants and stability constants are calculated, and the results are compared with literature. The results show that increasing the thorium concentration does not lead to polymer forms. refs., 42 figs., 19 tabs.

  2. Glomerular filtration rate

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/007305.htm Glomerular filtration rate To use the sharing features on this page, please enable JavaScript. Glomerular filtration rate (GFR) is a test used to check ...

  3. Rotary filtration system

    Science.gov (United States)

    Herman, David T.; Maxwell, David N.

    2011-04-19

    A rotary filtration apparatus for filtering a feed fluid into permeate is provided. The rotary filtration apparatus includes a container that has a feed fluid inlet. A shaft is at least partially disposed in the container and has a passageway for the transport of permeate. A disk stack made of a plurality of filtration disks is mounted onto the shaft so that rotation of the shaft causes rotation of the filtration disks. The filtration disks may be made of steel components and may be welded together. The shaft may penetrate a filtering section of the container at a single location. The rotary filtration apparatus may also incorporate a bellows seal to prevent leakage along the shaft, and an around the shaft union rotary joint to allow for removal of permeate. Various components of the rotary filtration apparatus may be removed as a single assembly.

  4. Formation of neptunium(IV)-silica colloids at near-neutral and slightly alkaline pH.

    Science.gov (United States)

    Husar, Richard; Weiss, Stephan; Hennig, Christoph; Hübner, René; Ikeda-Ohno, Atsushi; Zänker, Harald

    2015-01-06

    The reducing conditions in a nuclear waste repository render neptunium tetravalent. Thus, Np is often assumed to be immobile in the subsurface. However, tetravalent actinides can also become mobile if they occur as colloids. We show that Np(IV) is able to form silica-rich colloids in solutions containing silicic acid at concentrations of both the regions above and below the "mononuclear wall" of silicic acid at 2 × 10(-3) M (where silicic acid is expected to start polymerization). These Np(IV)-silica colloids have a size of only very few nanometers and can reach significantly higher concentrations than Np(IV) oxyhydroxide colloids. They can be stable in the waterborne form over longer spans of time. In the Np(IV)-silica colloids, the actinide--oxygen--actinide bonds are increasingly replaced by actinide--oxygen--silicon bonds due to structural incorporation of Si. Possible implications of the formation of such colloids for environmental scenarios are discussed.

  5. The Glomerular Filtration Barrier: Components and Crosstalk

    OpenAIRE

    Madhav C. Menon; Chuang, Peter Y.; Cijiang John He

    2012-01-01

    The glomerular filtration barrier is a highly specialized blood filtration interface that displays a high conductance to small and midsized solutes in plasma but retains relative impermeability to macromolecules. Its integrity is maintained by physicochemical and signalling interplay among its three core constituents—the glomerular endothelial cell, the basement membrane and visceral epithelial cell (podocyte). Understanding the pathomechanisms of inherited and acquired human diseases as well...

  6. Energy efficiency of neptunium redox battery in comparison with vanadium battery

    Energy Technology Data Exchange (ETDEWEB)

    Yamamura, T. [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Sendai, Miyagi 980-8577 (Japan); Watanabe, N. [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Sendai, Miyagi 980-8577 (Japan); Shiokawa, Y. [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Sendai, Miyagi 980-8577 (Japan)]. E-mail: shiokawa@imr.tohoku.ac.jp

    2006-02-09

    A neptunium ion possesses two isostructural and reversible redox couples (Np{sup 3+}/Np{sup 4+} and NpO{sub 2} {sup +}/NpO{sub 2} {sup 2+}) and is therefore suitable as an active material for a redox-flow battery. Since the plastic formed carbon (PFC) is known to show the largest k values for Np(IV)/Np(III) and Np(V)/Np(VI) reactions among various carbon electrodes, a cell was constructed by using the PFC, with the circulation induced by bubbling gas through the electrolyte. In discharge experiments with a neptunium and a vanadium battery using the cell, the former showed a lower voltage loss which suggests a smaller reaction overvoltage. Because of the high radioactivity of the neptunium, it was difficult to obtain sufficient circulation required for the redox-flow battery, therefore a model for evaluating the energy efficiency of the redox-flow battery was developed. By using the known k values for neptunium and vanadium electrode reactions at PFC electrodes, the energy efficiency of the neptunium battery was calculated to be 99.1% at 70 mA cm{sup -2}, which exceeds that of the vanadium battery by ca. 16%.

  7. Rapid and automated determination of plutonium and neptunium in environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, J.

    2011-03-15

    This thesis presents improved analytical methods for rapid and automated determination of plutonium and neptunium in environmental samples using sequential injection (SI) based chromatography and inductively coupled plasma mass spectrometry (ICP-MS). The progress of methodology development in this work consists of 5 subjects stated as follows: 1) Development and optimization of an SI-anion exchange chromatographic method for rapid determination of plutonium in environmental samples in combination of inductively coupled plasma mass spectrometry detection (Paper II); (2) Methodology development and optimization for rapid determination of plutonium in environmental samples using SI-extraction chromatography prior to inductively coupled plasma mass spectrometry (Paper III); (3) Development of an SI-chromatographic method for simultaneous determination of plutonium and neptunium in environmental samples (Paper IV); (4) Investigation of the suitability and applicability of 242Pu as a tracer for rapid neptunium determination using anion exchange chromatography in an SI-network coupled with inductively coupled plasma mass spectrometry (Paper V); (5) Exploration of macro-porous anion exchange chromatography for rapid and simultaneous determination of plutonium and neptunium within an SI system (Paper VI). The results demonstrate that the developed methods in this study are reliable and efficient for accurate assays of trace levels of plutonium and neptunium as demanded in different situations including environmental risk monitoring and assessment, emergency preparedness and surveillance of contaminated areas. (Author)

  8. Centrifugal membrane filtration -- Task 9

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    The Energy and Environmental Research Center (EERC) has teamed with SpinTek Membrane Systems, Inc., the developer of a centrifugal membrane filtration technology, to demonstrate applications for the SpinTek technology within the US Department of Energy (DOE) Environmental management (EM) Program. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. This is a crosscutting technology that falls under the Efficient Separations and Processing Crosscutting Program, with potential application to tank wastes, contaminated groundwater, landfill leachate, and secondary liquid waste streams from other remediation processes, including decontamination and decommissioning systems. Membrane-screening tests were performed with the SpinTek STC-X4 static test cell filtration unit, using five ceramic membranes with different pore size and composition. Based on permeate flux, a 0.25-{micro}m TiO{sub 2}/Al{sub 2}O{sub 3} membrane was selected for detailed performance evaluation using the SpinTek ST-IIL centrifugal membrane filtration unit with a surrogate tank waste solution. An extended test run of 100 hr performed on a surrogate tank waste solution showed some deterioration in filtration performance, based on flux, apparently due to the buildup of solids near the inner portion of the membrane where relative membrane velocities were low. Continued testing of the system will focus on modifications to the shear pattern across the entire membrane surface to affect improved long-term performance.

  9. The XPS study of physical and chemical forms of neptunium group on the surface of minerals

    Directory of Open Access Journals (Sweden)

    Teterin Anton Yu.

    2010-01-01

    Full Text Available The sorption behavior and the physical and chemical forms of neptunium on the surface of minerals of the two chlorate samples, biotite and kaolin, with different contents of Fe(II was studied. The liquid-liquid extraction and the X-ray photoelectron spectroscopy were employed to identify the valence forms of neptunium. On the basis of the obtained data the quantitative elemental composition of the surface of the studied minerals, as well as the ionic composition of the formed neptunium complexes was determined. It was shown that the Np(IV and Np(VI containing compounds did not form, while the complexes Np(VO+ -hydroxyl did form on the surface. The oxygen ions bonded with iron and oxygen belonging to water and/or of carboxyl were suggested to be present in the equatorial plane of the neptunyl group NpO+.

  10. Rapid and Automated Determination of Plutonium and Neptunium in Environmental Samples

    DEFF Research Database (Denmark)

    Qiao, Jixin

    and optimization for rapid determination of plutonium in environmental samples using SIextraction chromatography prior to inductively coupled plasma mass spectrometry (Paper III); (3) Development of an SI-chromatographic method for simultaneous determination of plutonium and neptunium in environmental samples...... (Paper IV); (4) Investigation of the suitability and applicability of 242Pu as a tracer for rapid neptunium determination using anion exchange chromatography in an SI-network coupled with inductively coupled plasma mass spectrometry (Paper V); (5) Exploration of macro-porous anion exchange chromatography......This thesis presents improved analytical methods for rapid and automated determination of plutonium and neptunium in environmental samples using sequential injection (SI) based chromatography and inductively coupled plasma mass spectrometry (ICP-MS). The progress of methodology development...

  11. Magnetic-seeding filtration

    Energy Technology Data Exchange (ETDEWEB)

    Ying, T.Y.; Chin, C.J.; Lu, S.C.; Yiacoumi, S. [Georgia Institute of Technology, Atlanta, GA (United States). School of Civil and Environmental Engineering] [and others

    1997-10-01

    Magnetic-seeding filtration consists of two steps: heterogeneous particle flocculation of magnetic and nonmagnetic particles in a stirred tank and high-gradient magnetic filtration (HGMF). The effects of various parameters affecting magnetic-seeding filtration (HGMF). The effects of various parameters affecting magnetic seeding filtration are theoretically and experimentally investigated. A trajectory model that includes hydrodynamic resistance, van der Waals, and electrostatic forces is developed to calculate the flocculation frequency in a turbulent-shear regime. Fractal dimension is introduced to simulate the open structure of aggregates. A magnetic-filtration model that consists of trajectory analysis, a particle build-up model, a breakthrough model, and a bivariate population-balance model is developed to predict the breakthrough curve of magnetic-seeding filtration. A good agreement between modeling results and experimental data is obtained. The results show that the model developed in this study can be used to predict the performance of magnetic-seeding filtration without using empirical coefficients or fitting parameters. 35 refs., 7 figs., 1 tab.

  12. Report on neptunium speciation by NMR and optical spectroscopies

    Energy Technology Data Exchange (ETDEWEB)

    Tait, C.D.; Palmer, P.D.; Ekberg, S.A.; Clark, D.L.

    1995-11-01

    Hydrolysis and carbonate complexation reactions were examined for NpO{sub 2}{sup 2+} and NpO{sub 2}{sup +} ions by a variety of techniques including potentiometric titration, UV-Vis-NIR and NMR spectroscopy. The equilibrium constant for the reaction 3NpO{sub 2}(CO{sub 3}){sub 3}{sup 4{minus}} + 3H{sup +} {rightleftharpoons} (NpO{sub 2}){sub 3}(CO{sub 3}){sub 6}{sup 6{minus}} + 3HCO{sub 3}{sup {minus}} was determined to be logK = 19.7 ({plus_minus} 0.8) (I = 2.5 m). {sup 17}O NMR spectroscopy of NpO{sub 2}{sup n+} ions (n = 1,2) reveals a readily observable {sup 17}O resonance for n = 2, but not for n = 1. The first hydrolysis constant for NpO{sub 2}{sup +} was studied as a function of temperature, and the functional form for the temperature-dependent equilibrium constant for the reaction written as NpO{sub 2}{sup +} + H{sub 2}O {rightleftharpoons} NpO{sub 2}OH + H{sup +} was found to be logK = 2.28 {minus} 3780/T, where T is in {degree}K. Finally, the temperature dependence of neptunium(V) carbonate complexation constants was studied. For the first carbonate complexation constant, the appropriate functional form was found to be log{beta}{sub 01} = 1.47 + 786/T.

  13. Factors Controlling Redox Speciation of Plutonium and Neptunium in Extraction Separation Processes

    Energy Technology Data Exchange (ETDEWEB)

    Paulenova, Alena [Principal Investigator; Vandegrift, III, George F. [Collaborator

    2013-09-24

    The objective of the project was to examine the factors controlling redox speciation of plutonium and neptunium in UREX+ extraction in terms of redox potentials, redox mechanism, kinetics and thermodynamics. Researchers employed redox-speciation extractions schemes in parallel to the spectroscopic experiments. The resulting distribution of redox species w studied uring spectroscopic, electrochemical, and spectro-electrochemical methods. This work reulted in collection of data on redox stability and distribution of redox couples in the nitric acid/nitrate electrolyte and the development of redox buffers to stabilize the desired oxidation state of separated radionuclides. The effects of temperature and concentrations on the redox behavior of neptunium were evaluated.

  14. Filtration in Porous Media

    DEFF Research Database (Denmark)

    Yuan, Hao; Shapiro, Alexander

    There is a considerable and ongoing effort aimed at understanding the transport and the deposition of suspended particles in porous media, especially non-Fickian transport and non-exponential deposition of particles. In this work, the influential parameters in filtration models are studied...... to understand their effects on the non-Fickian transport and the non-exponential deposition. The filtration models are validated by the comparisons between the modelling results and the experimental data.The elliptic equation with distributed filtration coefficients may be applied to model non-Fickian transport...... and hyperexponential deposition. The filtration model accounting for the migration of surface associated particles may be applied for non-monotonic deposition....

  15. Water Filtration Products

    Science.gov (United States)

    1986-01-01

    American Water Corporation manufactures water filtration products which incorporate technology originally developed for manned space operations. The formula involves granular activated charcoal and other ingredients, and removes substances by catalytic reactions, mechanical filtration, and absorption. Details are proprietary. A NASA literature search contributed to development of the compound. The technology is being extended to a deodorizing compound called Biofresh which traps gas and moisture inside the unit. Further applications are anticipated.

  16. Experimental study on neptunium migration under in situ geochemical conditions

    Science.gov (United States)

    Kumata, M.; Vandergraaf, T. T.

    1998-12-01

    Results are reported for migration experiments performed with Np under in situ geochemical conditions over a range of groundwater flow rates in columns of crushed rock in a specially designed facility at the 240-level of the Underground Research Laboratory (URL) near Pinawa, Manitoba, Canada. This laboratory is situated in an intrusive granitic rock formation, the Lac du Bonnet batholith. Highly altered granitic rock and groundwater were obtained from a major subhorizontal fracture zone at a depth of 250 m in the URL. The granite was wet-crushed and wet-sieved with groundwater from this fracture zone. The 180-850-μm size fraction was selected and packed in 20-cm long, 2.54-cm in diameter Teflon™-lined stainless steel columns. Approximately 30-ml vols of groundwater containing 3HHO and 237Np were injected into the columns at flow rates of 0.3, 1, and 3 ml/h, followed by elution with groundwater, obtained from the subhorizontal fracture, at the same flow rates, for a period of 95 days. Elution profiles for 3HHO were obtained, but no 237Np was detected in the eluted groundwater. After terminating the migration experiments, the columns were frozen, the column material was removed and cut into twenty 1-cm thick sections and each section was analyzed by gamma spectrometry. Profiles of 237Np were obtained for the three columns. A one-dimensional transport model was fitted to the 3HHO breakthrough curves to obtain flow parameters for this experiment. These flow parameters were in turn applied to the 237Np concentration profiles in the columns to produce sorption and dispersion coefficients for Np. The results show a strong dependence of retardation factors ( Rf) on flow rate. The decrease in the retarded velocity of the neptunium ( Vn) varied over one order of magnitude under the geochemical conditions for these experiments.

  17. Visualization of water flow during filtration using flat filtration materials

    Directory of Open Access Journals (Sweden)

    Hrůza Jakub

    2012-04-01

    Full Text Available Filtration materials are very important elements of some industrial appliances. Water filtration is a separation of solid materials from fluid. Solid particles are captured on the frontal area of the filtration textile and only liquid passes through it. It is important to know the filtration process in a detailed way to be able to develop filtration materials. Visualization of filtration process enables a better view of the filtration. This method also enables to determine efficiency and homogeneity of filtration using image analysis. For this purpose, a new waterfiltration measuring setup was proposed and constructed. Filtration material is mounted into the optically transparent place in the setup. Laser sheet is directed into this place as in the case of Particle Image Velocimetry measuring method. Monochrome and sensitive camera records the light scattered by seeding particles in water. The seeding particles passing through the filter serve for measuring filtration efficiency, and also for visualization of filtration process. Filtration setup enables to measure also the pressure drop and a flow. The signals are processed by National Instruments compactDAQ system and UMA software. Microfibrous and nanofibrous filtration materials are tested by this measuring method. In the case of nanofibrous filtration, appropriate size of seeding particles is needed to be used to perform a process of filtration.

  18. Salt disposition alternatives filtration at SRTC

    Energy Technology Data Exchange (ETDEWEB)

    Walker, B. W.; Hobbs, D.

    2000-01-27

    Several of the prospective salt disposition alternative technologies require a monosodium titanate (MST) contact to remove strontium and actinides from inorganic salt solution feedstock. This feedstock also contains sludge solids from waste removal operations and may contain defoamers added in the evaporator systems. Filtration is required to remove the sludge and MST solids before sending the salt solution for further processing. This report describes testing performed using the Parallel Theological Experimental Filter (PREF). The PREF contains two single tube Mott sintered metal crossflow filters. For this test one filter was isolated so that the maximum velocities could be achieved. Previous studies showed slurries of MST and sludge in the presence of sodium tetraphenylborate (NaTPB) were filterable since the NaTPB slurry formed a filter cake which aided in removing the smaller MST and sludge particles. Some of the salt disposition alternative technologies do not use NaTPB raising the question of how effective crossflow filtration is with a feed stream containing only sludge and MST. Variables investigated included axial velocity, transmembrane pressure, defoamer effects, and solids concentration (MST and sludge). Details of the tests are outlined in the technical report WSRC-RP-98-O0691. Key conclusions from this study are: (1) Severe fouling of the Mott sintered metal filter did not occur with any of the solutions filtered. (2) The highest fluxes, in the range of .46 to 1.02 gpm/f{sup 2}, were obtained when salt solution decanted from settled solids was fed to the filter. These fluxes would achieve 92 to 204 gpm filtrate production for the current ITP filters. The filtrate fluxes were close to the flux of 0.42 gpm/f{sup 2} reported for In Tank Precipitation Salt Solution by Morrisey. (3) For the range of solids loading studied, the filter flux ranged from .04 to .17 gpm/f{sup 2} which would result in a filtrate production rate of 9 to 31 gpm for the current HP

  19. Filtration of engineered nanoparticles using porous membranes

    NARCIS (Netherlands)

    Trzaskus, Krzystof

    2016-01-01

    The research presented in this thesis aims at providing a better understanding of the fundamental aspects responsible for nanoparticle removal and fouling development during filtration of engineered nanoparticles. The emphasis is put on the role of interparticle interactions in the feed solution,

  20. Microfluidic colloid filtration

    Science.gov (United States)

    Linkhorst, John; Beckmann, Torsten; Go, Dennis; Kuehne, Alexander J. C.; Wessling, Matthias

    2016-03-01

    Filtration of natural and colloidal matter is an essential process in today’s water treatment processes. The colloidal matter is retained with the help of micro- and nanoporous synthetic membranes. Colloids are retained in a “cake layer” – often coined fouling layer. Membrane fouling is the most substantial problem in membrane filtration: colloidal and natural matter build-up leads to an increasing resistance and thus decreasing water transport rate through the membrane. Theoretical models exist to describe macroscopically the hydrodynamic resistance of such transport and rejection phenomena; however, visualization of the various phenomena occurring during colloid retention is extremely demanding. Here we present a microfluidics based methodology to follow filter cake build up as well as transport phenomena occuring inside of the fouling layer. The microfluidic colloidal filtration methodology enables the study of complex colloidal jamming, crystallization and melting processes as well as translocation at the single particle level.

  1. CENTRIFUGAL MEMBRANE FILTRATION

    Energy Technology Data Exchange (ETDEWEB)

    Daniel J. Stepan; Bradley G. Stevens; Melanie D. Hetland

    1999-10-01

    The overall project consists of several integrated research phases related to the applicability, continued development, demonstration, and commercialization of the SpinTek centrifugal membrane filtration process. Work performed during this reporting period consisted of Phase 2 evaluation of the SpinTek centrifugal membrane filtration technology and Phase 3, Technology Partnering. During Phase 1 testing conducted at the EERC using the SpinTek ST-IIL unit operating on a surrogate tank waste, a solids cake developed on the membrane surface. The solids cake was observed where linear membrane velocities were less than 17.5 ft/s and reduced the unobstructed membrane surface area up to 25%, reducing overall filtration performance. The primary goal of the Phase 2 research effort was to enhance filtration performance through the development and testing of alternative turbulence promoter designs. The turbulence promoters were designed to generate a shear force across the entire membrane surface sufficient to maintain a self-cleaning membrane capability and improve filtration efficiency and long-term performance. Specific Phase 2 research activities included the following: System modifications to accommodate an 11-in.-diameter, two-disk rotating membrane assembly; Development and fabrication of alternative turbulence promoter designs; Testing and evaluation of the existing and alternative turbulence promoters under selected operating conditions using a statistically designed test matrix; and Data reduction and analysis; The objective of Phase 3 research was to demonstrate the effectiveness of SpinTek's centrifugal membrane filtration as a pretreatment to remove suspended solids from a liquid waste upstream of 3M's WWL cartridge technology for the selective removal of technetium (Tc).

  2. Magnetic-seeding filtration

    Energy Technology Data Exchange (ETDEWEB)

    Depaoli, D. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    This task will investigate the capabilities of magnetic-seeding filtration for the enhanced removal of magnetic and nonmagnetic particulates from liquids. This technology appies to a wide range of liquid wastes, including groundwater, process waters, and tank supernatant. Magnetic-seeding filtration can be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal-size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes.

  3. Filtration by eyelashes

    Science.gov (United States)

    Vistarakula, Krishna; Bergin, Mike; Hu, David

    2010-11-01

    Nearly every mammalian and avian eye is rimmed with lashes. We investigate experimentally the ability of lashes to reduce airborne particle deposition in the eye. We hypothesize that there is an optimum eyelash length that maximizes both filtration ability and extent of peripheral vision. This hypothesis is tested using a dual approach. Using preserved heads from 36 species of animals at the American Museum of Natural History, we determine the relationship between eye size and eyelash geometry (length and spacing). We test the filtration efficacy of these geometries by deploying outdoor manikins and measuring particle deposition rate as a function of eyelash length.

  4. Enlargements of filtrations and applications

    CERN Document Server

    Corcuera, J M

    2012-01-01

    In this paper we review some old and new results about the enlargement of filtrations problem, as well as their applications to credit risk and insider trading problems. The enlargement of filtrations problem consists in the study of conditions under which a semimartingale remains a semimartingale when the filtration is enlarged, and, in such a case, how to find the Doob-Meyer decomposition. Filtrations may be enlarged in different ways. In this paper we consider initial and progressive filtration enlargements made by random variables and processes. Keywords: Credit Risk, Insider Trading, Enlargement of Filtrations

  5. Water Treatment Technology - Filtration.

    Science.gov (United States)

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on filtration provides instructional materials for six competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: purposes of sedimentation basins and flocculation…

  6. The Glomerular Filtration Barrier: Components and Crosstalk

    Directory of Open Access Journals (Sweden)

    Madhav C. Menon

    2012-01-01

    Full Text Available The glomerular filtration barrier is a highly specialized blood filtration interface that displays a high conductance to small and midsized solutes in plasma but retains relative impermeability to macromolecules. Its integrity is maintained by physicochemical and signalling interplay among its three core constituents—the glomerular endothelial cell, the basement membrane and visceral epithelial cell (podocyte. Understanding the pathomechanisms of inherited and acquired human diseases as well as experimental injury models of this barrier have helped to unravel this interdependence. Key among the consequences of interference with the integrity of the glomerular filtration barrier is the appearance of significant amounts of proteins in the urine. Proteinuria correlates with kidney disease progression and cardiovascular mortality. With specific reference to proteinuria in human and animal disease phenotypes, the following review explores the roles of the endothelial cell, glomerular basement membrane, and the podocyte and attempts to highlight examples of essential crosstalk within this barrier.

  7. Description of three-phase filtration with a novel dimensionless number

    NARCIS (Netherlands)

    Huizenga, P.; Kuipers, J.A.M.; Swaaij, van W.P.M.

    1998-01-01

    Internal filtration in slurry bubble columns offers a possible solution to the filtration problems related to this reactor type. The applicability of the concept has already been demonstrated at full-scale for wastewater treatment, even though a theoretical description of internal filtration is lack

  8. Chemical speciation of neptunium in spent fuel. Annual report for period 15 August 1999 to 15 August 2000

    Energy Technology Data Exchange (ETDEWEB)

    Ken Czerwinski; Don Reed

    2000-09-01

    (B204) This project will examine the chemical speciation of neptunium in spent nuclear fuel. The R&D fields covered by the project include waste host materials and actinide chemistry. Examination of neptunium is chosen since it was identified as a radionuclide of concern by the NERI workshop. Additionally, information on the chemical form of neptunium in spent fuel is lacking. The identification of the neptunium species in spent fuel would allow a greater scientific based understanding of its long-term fate and behavior in waste forms. Research to establish the application and development of X-ray synchrotrons radiation (XSR) techniques to determine the structure of aqueous, adsorbed, and solid actinide species of importance to nuclear considerations is being conducted at Argonne. These studies extend current efforts within the Chemical Technology Division at Argonne National Laboratory to investigate actinide speciation with more conventional spectroscopic and solids characterization (e.g. SEM, TEM, and XRD) methods. Our project will utilize all these techniques for determining neptunium speciation in spent fuel. We intend to determine the chemical species and oxidation state of neptunium in spent fuel and alteration phases. Different types of spent fuel will be examined. Once characterized, the chemical behavior of the identified neptunium species will be evaluated if it is not present in the literature. Special attention will be given to the behavior of the neptunium species under typical repository near-field conditions (elevated temperature, high pH, varying Eh). This will permit a timely inclusion of project results into near-field geochemical models. Additionally, project results and methodologies have applications to neptunium in the environment, or treatment of neptunium containing waste. Another important aspect of this project is the close cooperation between a university and a national laboratory. The PI has a transuranic laboratory at MIT where

  9. Internal filtration, filtration fraction, and blood flow resistance in high- and low-flux dialyzers.

    Science.gov (United States)

    Schneditz, Daniel; Zierler, Edda; Vanholder, Raymond; Eloot, Sunny

    2014-01-01

    It was the aim to examine the fluid flow in blood and dialysate compartments of highly permeable hollow fiber dialyzers where internal filtration contributes to solute removal but where excessive filtration bears a risk of cell activation and damage. Flow characteristics of high- (HF) and low-flux (LF) dialyzers were studied in lab-bench experiments using whole bovine blood. Measurements obtained under different operating conditions and under zero net ultrafiltration were compared to theoretical calculations obtained from a mathematical model. Experimental resistances in the blood compartment were within ±2% of those calculated from the model when dialysate was used as a test fluid. With whole blood, the experimental resistances in the blood compartment were only 81.8 ± 2.8% and 83.7 ± 4.3% of those calculated for the LF and HF dialyzer, respectively. Surprisingly, measured blood flow resistance slightly but significantly decreased with increasing flow rate (p filtration fraction, while overall internal filtration increased. The increase in internal filtration when increasing blood flow is associated with a beneficial reduction in internal filtration fraction. Concerns of increased hemoconcentration when increasing blood flow therefore appear to be unwarranted.

  10. Long-term desorption behavior of uranium and neptunium in heterogeneous volcanic tuff materials /

    Energy Technology Data Exchange (ETDEWEB)

    Dean, Cynthia A.

    2010-05-01

    Uranium and neptunium desorption were studied in long-term laboratory experiments using four well-characterized volcanic tuff cores collected from southeast of Yucca Mountain, Nevada. The objectives of the experiments were to 1. Demonstrate a methodology aimed at characterizing distributions of sorption parameters (attributes of multiple sorption sites) that can be applied to moderately-sorbing species in heterogeneous systems to provide more realistic reactive transport parameters and a more realistic approach to modeling transport in heterogeneous systems. 2. Focus on uranium and neptunium because of their high solubility, relatively weak sorption, and high contributions to predicted dose in Yucca Mountain performance assessments. Also, uranium is a contaminant of concern at many DOE legacy sites and uranium mining sites.

  11. Comparison of sample preparation methods for reliable plutonium and neptunium urinalysis using automatic extraction chromatography.

    Science.gov (United States)

    Qiao, Jixin; Xu, Yihong; Hou, Xiaolin; Miró, Manuel

    2014-10-01

    This paper describes improvement and comparison of analytical methods for simultaneous determination of trace-level plutonium and neptunium in urine samples by inductively coupled plasma mass spectrometry (ICP-MS). Four sample pre-concentration techniques, including calcium phosphate, iron hydroxide and manganese dioxide co-precipitation and evaporation were compared and the applicability of different techniques was discussed in order to evaluate and establish the optimal method for in vivo radioassay program. The analytical results indicate that the various sample pre-concentration approaches afford dissimilar method performances and care should be taken for specific experimental parameters for improving chemical yields. The best analytical performances in terms of turnaround time (6h) and chemical yields for plutonium (88.7 ± 11.6%) and neptunium (94.2 ± 2.0%) were achieved by manganese dioxide co-precipitation. The need of drying ashing (≥ 7h) for calcium phosphate co-precipitation and long-term aging (5d) for iron hydroxide co-precipitation, respectively, rendered time-consuming analytical protocols. Despite the fact that evaporation is also somewhat time-consuming (1.5d), it endows urinalysis methods with better reliability and repeatability compared with co-precipitation techniques. In view of the applicability of different pre-concentration techniques proposed previously in the literature, the main challenge behind relevant method development is pointed to be the release of plutonium and neptunium associated with organic compounds in real urine assays. In this work, different protocols for decomposing organic matter in urine were investigated, of which potassium persulfate (K2S2O8) treatment provided the highest chemical yield of neptunium in the iron hydroxide co-precipitation step, yet, the occurrence of sulfur compounds in the processed sample deteriorated the analytical performance of the ensuing extraction chromatographic separation with chemical

  12. Surface complexation of neptunium (V) onto whole cells and cell componets of Shewanella alga

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Donald Timothy [Los Alamos National Laboratory; Deo, Randhir P [ASU; Rittmann, Bruce E [ASU; Songkasiri, Warinthorn [UNAFFILIATED

    2008-01-01

    We systematically quantified surface complexation of neptunium(V) onto whole cells of Shewanella alga strain BrY and onto cell wall and extracellular polymeric substances (EPS) of S. alga. We first performed acid and base titrations and used the mathematical model FITEQL with constant-capacitance surface-complexation to determine the concentrations and deprotonation constants of specific surface functional groups. Deprotonation constants most likely corresponded to a carboxyl site associated with amino acids (pK{sub a} {approx} 2.4), a carboxyl group not associated with amino acids (pK{sub a} {approx} 5), a phosphoryl site (pK{sub a} {approx} 7.2), and an amine site (pK{sub a} > 10). We then carried out batch sorption experiments with Np(V) and each of the S. alga components at different pHs. Results show that solution pH influenced the speciation of Np(V) and each of the surface functional groups. We used the speciation sub-model of the biogeochemical model CCBATCH to compute the stability constants for Np(V) complexation to each surface functional group. The stability constants were similar for each functional group on S. alga bacterial whole cells, cell walls, and EPS, and they explain the complicated sorption patterns when they are combined with the aqueous-phase speciation of Np(V). For pH < 8, NpO{sub 2}{sup +} was the dominant form of Np(V), and its log K values for the low-pK{sub a} carboxyl, other carboxyl, and phosphoryl groups were 1.75, 1.75, and 2.5 to 3.1, respectively. For pH greater than 8, the key surface ligand was amine >XNH3+, which complexed with NpO{sub 2}(CO{sub 3}){sub 3}{sup 5-}. The log K for NpO{sub 2}(CO{sub 3}){sub 3}{sup 5-} complexed onto the amine groups was 3.1 to 3.6. All of the log K values are similar to those of Np(V) complexes with aqueous carboxyl and N-containing carboxyl ligands. These results point towards the important role of surface complexation in defining key actinide-microbiological interactions in the subsurface.

  13. Dynamic optical filtration

    Science.gov (United States)

    Chretien, Jean-Loup (Inventor); Lu, Edward T. (Inventor)

    2005-01-01

    A dynamic optical filtration system and method effectively blocks bright light sources without impairing view of the remainder of the scene. A sensor measures light intensity and position so that selected cells of a shading matrix may interrupt the view of the bright light source by a receptor. A beamsplitter may be used so that the sensor may be located away from the receptor. The shading matrix may also be replaced by a digital micromirror device, which selectively sends image data to the receptor.

  14. Magnetic flocculation and filtration

    Energy Technology Data Exchange (ETDEWEB)

    Yiacoumi, Sotira; Chin, Ching-Ju; Yin, Tung-Yu [Georgia Inst. of Tech., Atlanta, GA (United States). School of Civil and Environmental Engineering; Tsouris, C., DePaoli, D.W.; Chattin, M.R.; Spurrier, M. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    A model is available in predicting flocculation frequencies between particles of various properties under the influence of a magnetic field. This model provides a basic understanding of fundamental phenomena, such as particle-particle and particle-collector interactions, occurring in HGMF (high gradient magnetic field), and will be extended to describe experimental data of particle flocculation and filtration and predict the performance of high- gradient magnetic filters. It is also expected that this model will eventually lead to a tool for design and optimization of magnetic filters for environmental, metallurgical, biochemical, and other applications.

  15. Magnetic-seeding filtration

    Energy Technology Data Exchange (ETDEWEB)

    DePaoli, D.W.; Tsouris, C. [Oak Ridge National Lab., TN (United States); Yiacoumi, Sotira

    1997-10-01

    Magnetic-seeding filtration is a technology under development for the enhanced removal of magnetic and non-magnetic particulates from liquids. This process involves the addition of a small amount of magnetic seed particles (such as naturally occurring iron oxide) to a waste suspension, followed by treatment with a magnetic filter. Non-magnetic and weakly magnetic particles are made to undergo nonhomogeneous flocculation with the seed particles, forming flocs of high magnetic susceptibility that are readily removed by a conventional high-gradient magnetic filter. This technology is applicable to a wide range of liquid wastes, including groundwater, process waters, and tank supernatants. Magnetic-seeding filtration may be used in several aspects of treatment, such as (1) removal of solids, particularly those in the colloidal size range that are difficult to remove by conventional means; (2) removal of contaminants by precipitation processes; and (3) removal of contaminants by sorption processes. Waste stream characteristics for which the technology may be applicable include (1) particle sizes ranging from relatively coarse (several microns) to colloidal particles, (2) high or low radiation levels, (3) broad-ranging flow rates, (4) low to moderate solids concentration, (5) cases requiring high decontamination factors, and (6) aqueous or non-aqueous liquids. At this point, the technology is at the bench-scale stage of development; laboratory studies and fundamental modeling are currently being employed to determine the capabilities of the process.

  16. Additive Difference Schemes for Filtration Problems in Multilayer Systems

    CERN Document Server

    Ayrjan, E A; Pavlush, M; Fedorov, A V

    2000-01-01

    In the present paper difference schemes for solution of the plane filtration problem in multilayer systems are analyzed within the framework of difference schemes general theory. Attention is paid to splitting the schemes on physical processes of filtration along water-carring layers and vertical motion between layers. Some absolutely stable additive difference schemes are obtained the realization of which needs no software modification. Parallel algorithm connected with the solving of the filtration problem in every water-carring layer on a single processor is constructed. Program realization on the multi-processor system SPP2000 at JINR is discussed.

  17. Filtration ATF in automatic transmissions (AT) of cars

    OpenAIRE

    Tadeusz Dziubak; Paweł Szczepaniak

    2014-01-01

    Functions and conditions of work of suction ATF filters are presented. Requirements ofATF filters are discussed. Sources of contaminations ATF are presented. ATF filtration system wascharacterized. Classification of ATF filters and their selection of design solutions are presented. Filtermaterials used for the production of ATF suction filters are presented and characterized. Conditions ofthe work of suction ATF filters were analyzed. Hydraulic and filtration characteristics are discussed.[b]...

  18. Modus of filtration.

    Science.gov (United States)

    Meltzer, Theodore H

    2006-01-01

    Experience teaches that particles larger than the pores of a filter cannot negotiate its passage. Other retention mechanisms are less obvious than sieve retention or size exclusion. They are electrical in nature, and find expression in the bonding alliances that mutually attract (or repel) filters and particles. The influence of hydrogen bonds, of van der Waals forces, of hydrophobic adsorptions, and of transient polarities on particle retentions are set forth in terms of the double electrical layer concept that also governs colloidal destabilizations. The origins of differences in membrane porosities is explained, as also the importance of the filtration conditions. The singularity of the particle-fluid-filter relationship on organism and/or pore size alteration is stressed.

  19. Filtration properties of nonwovens.

    Science.gov (United States)

    Gador, W; Jankowska, E

    1999-01-01

    This paper presents the results and conclusions from experimental investigations concerning filtration properties of nonwovens. The needled nonwovens were made from polyester fibres (PTE) with average fibre diameter 12 micrometres and polypropylene fibres (PP) with average fibre diameter 32 micrometres. Nonwovens were produced out of each of those fibres or out of a mixture of polyester and polypropylene fibres. This paper also presents investigations of nonwoven fabric made of polypropylene fibres (PP) with average fibre diameter 2.6 micrometres, which was formed according to melt-blown technology. Oil mist, as challenge aerosol, was used to evaluate the performance of filter media at various aerosol velocities. The average oil mist test aerosol particle diameter was 0.3 micrometre. Filter penetration was measured at oil mist concentration 0.24 g/m(3).

  20. Air filtration in HVAC systems

    CERN Document Server

    Ginestet, Alain; Tronville, Paolo; Hyttinen, Marko

    2010-01-01

    Air filtration Guidebook will help the designer and user to understand the background and criteria for air filtration, how to select air filters and avoid problems associated with hygienic and other conditions at operation of air filters. The selection of air filters is based on external conditions such as levels of existing pollutants, indoor air quality and energy efficiency requirements.

  1. Neptunium(V) sorption behavior on clinoptilolite, quartz and montmorillonite

    Energy Technology Data Exchange (ETDEWEB)

    Bertetti, F.P.; Pabalan, R.T.; Turner, D.R.; Almendarez, M.G. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses

    1996-08-01

    Performance assessment models have identified {sup 237}Np as a radionuclide of concern in meeting release limits established for the geologic disposal of high-level nuclear waste at the proposed repository at Yucca Mountain, Nevada. In this study, quartz, clinoptilolite, and montmorillonite, which are minerals representative of phases that occur both in the rock matrix and as fracture coatings at Yucca Mountain, were reacted with {sup 237}Np-bearing solutions to characterize the sorption behavior of Np(V) on these minerals. Batch experiments were conducted over a wide range of conditions in which pH of solution, surface loading, sorbent surface area, initial concentration of Np(V), and partial pressure of CO{sub 2} were varied. Initial Np(V) concentrations were between 1 {times} 10{sup {minus}7} and 1 {times} 10{sup {minus}6} M in electrolyte solutions of 0.1 or 0.01 M NaNO{sub 3}. The oxidation state of Np in solution was verified with NIR spectroscopy and by solvent extraction. Prior to the start of experiments, minerals were pretreated to eliminate impurities, and the clinoptilolite and montmorillonite were converted to Na-form by ion exchange with NaCl solutions. Results indicate that, for all three minerals, Np(V) sorption begins at pH values coincident with the start of hydrolysis in solution ({approximately}7). For solutions undersaturated with respect to atmospheric CO{sub 2}, sorption increases continuously with increasing pH. Under equilibrium with atmospheric CO{sub 2}, Np(V) sorption is important in the pH range (7--9.5) where NpO{sub 2}(OH){sup 0}(aq) is significant, whereas sorption is inhibited at higher pH where neptunyl carbonate complexes are the predominant species.

  2. Standard guide for determination of plutonium and neptunium in uranium hexafluoride by alpha spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This method covers the determination of plutonium and neptunium isotopes in uranium hexafluoride by alpha spectroscopy. The method can also be applicable to any matrix that may be converted to a nitric acid system. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.

  3. Filtrating forms of soil bacteria

    Science.gov (United States)

    Van'kova, A. A.; Ivanov, P. I.; Emtsev, V. T.

    2013-03-01

    Filtrating (ultramicroscopic) forms (FF) of bacteria were studied in a soddy-podzolic soil and the root zone of alfalfa plants as part of populations of the most widespread physiological groups of soil bacteria. FF were obtained by filtering soil solutions through membrane filters with a pore diameter of 0.22 μm. It was established that the greater part of the bacteria in the soil and in the root zone of the plants has an ultramicroscopic size: the average diameter of the cells is 0.3 μm, and their length is 0.6 μm, which is significantly less than the cell size of banal bacteria. The number of FF varies within a wide range depending on the physicochemical conditions of the habitat. The FF number's dynamics in the soil is of a seasonal nature; i.e., the number of bacteria found increases in the summer and fall and decreases in the winter-spring period. In the rhizosphere of the alfalfa, over the vegetation period, the number of FF and their fraction in the total mass of the bacteria increase. A reverse tendency is observed in the rhizoplane. The morphological particularities (identified by an electron microscopy) and the nature of the FF indicate their physiological activity.

  4. Neptunium redox behavior and solubility in J-13 conditions

    Energy Technology Data Exchange (ETDEWEB)

    Efurd, D.W.; Runde, W.; Tait, C.D.

    1997-08-01

    In order to confirm that the redox reaction Np(V) to Np(IV) may occur, studies are being conducted including exposure of Np(V) to solutions of known E{sub h} vs pH, temperature. Analytic results from ongoing solubility experiments from undersaturation, using Np solids formed in previous oversaturation experiments, are reported.

  5. Problems of multiphase fluid filtration

    CERN Document Server

    Konovalov, AN

    1994-01-01

    This book deals with a spectrum of problems related to the mathematical modeling of multiphase filtration. Emphasis is placed on an inseparable triad: model - algorithm - computer code. An analysis of new and traditional filtration problems from the point of view of both their numerical implementation and the reproduction of one or another technological characteristics of the processes under consideration is given. The basic principles which underlie the construction of efficient numerical methods taking into account the filtration problems are discussed: non-evolutionary nature, degeneration,

  6. Latest aspects of mechanical filtration

    Directory of Open Access Journals (Sweden)

    Stanislav Koláček

    2013-01-01

    Full Text Available The aim of this study was to describe and unify all knowledge about mechanic filtration. The first part deals with the parameters and properties of filtration. Here some important basic concepts are explained such as pressure gradient, filter life, etc. There’s also a description of convenient filtration technology for coarse and fine materials, such as sand, smoke or soot. The second part primarily focuses on the real use and application of filters for liquid and gaseous media. The differences in construction between different types of filters for filtration of fuels, oils, hydraulic fluids, air and cabin filters are described. The last section is focused mainly on new materials for the production of filters. These materials are ceramic or nanomaterials, which can actually be enriched for example with antibacterial silver or some fungicides.

  7. Health benefits of particle filtration.

    Science.gov (United States)

    Fisk, W J

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also, reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percentage improvement in health outcomes is typically modest, for example, 7% to 25%. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  8. Health Benefits of Particle Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percentage improvement in health outcomes is typically modest, e.g., 7percent to 25percent. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  9. Health Benefits of Particle Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also, reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percent age improvement in health outcomes is typically modest, for example, 7percent to 25percent. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  10. Effect of Membrane Fouling by PVA Addition in Simulated EPS Solution on Cross-flow Filtration%聚乙烯醇(PVA)对模拟胞外聚合物(EPS)在错流超滤中膜污染的影响

    Institute of Scientific and Technical Information of China (English)

    王歌; 李方; 吴亮; 付乐乐

    2012-01-01

    研究了在模拟胞外聚合物(EPS)溶液中添加聚乙烯醇(PVA)对错流超滤膜过滤过程的影响.对有无添加PVA的模拟EPS溶液分别用错流平板膜进行超滤实验,用Hermia修正模型对实验数据进行拟合,分析验证膜污染机理.结果表明,无论是否添加PVA,模拟溶液的通量-时间实验数据对滤饼堵塞模型的拟合度都最高,为0.891~0.994;添加PVA的模拟EPS溶液形成的吸附阻力和膜污染阻力均比无添加的溶液高约0.5倍,滤饼比阻比无添加的溶液高约4倍,分别为2.29×1014和9.57×1014 m-1;模拟EPS溶液添加PVA后,通量对操作压力的敏感度增加,对膜面流速的敏感度却降低.%The effect of polyvinyl alcohol (PVA) addition on the performance of cross-flow membrane filtration of model extracellular polymeric substances (EPS) solution was studied. Filtrations of model EPS solution with and without PVA were conducted in a cross-flow filtration cell through ultrafiltration (UF) membranes respectively. Hermia modified model was used to check the fouling mechanism by fitting of the experimental data. The results show that the cake filtration model fits to the experimental data the best in UF experiments regardless of addition of PVA, the degree of fitting ranges from 0.891 to 0.994, the adsorption resistance and membrane pollution resistance of the model EPS solution with addition of PVA is higher by half than that of model EPS solution, the specific cake resistance is four times higher, 2.29×1014 and 9.57×1014 m-1 respectively, the sensitivity of flux to the operating pressure is increased with addition of PVA, but the sensitivity to the velocity of the membrane surface reduced.

  11. Modeling Water Filtration

    Science.gov (United States)

    Parks, Melissa

    2014-01-01

    Model-eliciting activities (MEAs) are not new to those in engineering or mathematics, but they were new to Melissa Parks. Model-eliciting activities are simulated real-world problems that integrate engineering, mathematical, and scientific thinking as students find solutions for specific scenarios. During this process, students generate solutions…

  12. Filtration and compression of organic materials

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Keiding, Kristian

    The conventional filtration theory has been based on filtrations of incompressible particles such as anatase, kaolin and clay. The filtration models have later been used for organic slurries but can often not explain the observed experimental data. At constant pressure, the filtrate volume does...

  13. 40 CFR 141.73 - Filtration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Filtration. 141.73 Section 141.73... PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.73 Filtration. A public water system..., and does not meet all of the criteria in § 141.71 (a) and (b) for avoiding filtration, must...

  14. LIBS Spectral Data for a Mixed Actinide Fuel Pellet Containing Uranium, Plutonium, Neptunium and Americium

    Energy Technology Data Exchange (ETDEWEB)

    Judge, Elizabeth J. [Los Alamos National Laboratory; Berg, John M. [Los Alamos National Laboratory; Le, Loan A. [Los Alamos National Laboratory; Lopez, Leon N. [Los Alamos National Laboratory; Barefield, James E. [Los Alamos National Laboratory

    2012-06-18

    Laser-induced breakdown spectroscopy (LIBS) was used to analyze a mixed actinide fuel pellet containing 75% UO{sub 2}/20% PuO{sub 2}/3% AmO{sub 2}/2% NpO{sub 2}. The preliminary data shown here is the first report of LIBS analysis of a mixed actinide fuel pellet, to the authors knowledge. The LIBS spectral data was acquired in a plutonium facility at Los Alamos National Laboratory where the sample was contained within a glove box. The initial installation of the glove box was not intended for complete ultraviolet (UV), visible (VIS) and near infrared (NIR) transmission, therefore the LIBS spectrum is truncated in the UV and NIR regions due to the optical transmission of the window port and filters that were installed. The optical collection of the emission from the LIBS plasma will be optimized in the future. However, the preliminary LIBS data acquired is worth reporting due to the uniqueness of the sample and spectral data. The analysis of several actinides in the presence of each other is an important feature of this analysis since traditional methods must chemically separate uranium, plutonium, neptunium, and americium prior to analysis. Due to the historic nature of the sample fuel pellet analyzed, the provided sample composition of 75% UO{sub 2}/20% PuO{sub 2}/3% AmO{sub 2}/2% NpO{sub 2} cannot be confirm without further analytical processing. Uranium, plutonium, and americium emission lines were abundant and easily assigned while neptunium was more difficult to identify. There may be several reasons for this observation, other than knowing the exact sample composition of the fuel pellet. First, the atomic emission wavelength resources for neptunium are limited and such techniques as hollow cathode discharge lamp have different dynamics than the plasma used in LIBS which results in different emission spectra. Secondly, due to the complex sample of four actinide elements, which all have very dense electronic energy levels, there may be reactions and

  15. Redox stability of neptunium(V) and neptunium(IV) in the presence of humic substances of varying functionality

    Energy Technology Data Exchange (ETDEWEB)

    Schmeide, K.; Bernhard, G. [Forschungszentrum Dresden-Rossendorf, Inst. of Radiochemistry, Dresden (Germany)

    2009-07-01

    The reducing properties of humic substances (humic acid (HA) and fulvic acid (FA)) of varying functionality towards Np(V) have been studied under anaerobic conditions between pH 3.5 and pH 9.0 in batch experiments. For Np redox speciation in solution solvent extraction, NIR absorption spectroscopy and ultrafiltration were applied. The reduction rate varied with type of humic substances, solution pH. HA to Np concentration ratio, and equilibration time. In comparison to natural humic substances, synthetic HA with designed redox properties lead to a stronger reduction of Np(V) to Np(IV). The reducing capacities of humic substances towards Np(V) could be correlated to their phenolic/acidic OH group content, which includes both hydroquinone-like moieties and non-quinoid phenols. By applying a synthetic HA with blocked phenolic/acidic OH groups, the dominance of phenolic/acidic OH groups as the redox-active moieties of humic substances was verified. The Np(IV) formed in the course of the experiments is predominantly humic colloid-bound. Np(IV) oxo/hydroxide colloids, that might be formed in addition, are stabilized by adsorbed humic substances. The remaining Np(V) occurs as NpO{sub 2}{sup +} ion or Np(V) humate depending on pH. The ability of synthetic HA to effectively maintain Np in the tetravalent state during humate complexation experiments could be shown. (orig.)

  16. Emulsions for interfacial filtration.

    Energy Technology Data Exchange (ETDEWEB)

    Grillet, Anne Mary; Bourdon, Christopher Jay; Souza, Caroline Ann; Welk, Margaret Ellen; Hartenberger, Joel David; Brooks, Carlton, F.

    2006-11-01

    We have investigated a novel emulsion interfacial filter that is applicable for a wide range of materials, from nano-particles to cells and bacteria. This technology uses the interface between the two immiscible phases as the active surface area for adsorption of targeted materials. We showed that emulsion interfaces can effectively collect and trap materials from aqueous solution. We tested two aqueous systems, a bovine serum albumin (BSA) solution and coal bed methane produced water (CBMPW). Using a pendant drop technique to monitor the interfacial tension, we demonstrated that materials in both samples were adsorbed to the liquid-liquid interface, and did not readily desorb. A prototype system was built to test the emulsion interfacial filter concept. For the BSA system, a protein assay showed a progressive decrease in the residual BSA concentration as the sample was processed. Based on the initial prototype operation, we propose an improved system design.

  17. Neptunium(V) Adsorption to Bacteria at Low and High Ionic Strength

    Science.gov (United States)

    Ams, D.; Swanson, J. S.; Reed, D. T.

    2010-12-01

    Np(V) is expected to be the predominant oxidation state of neptunium in aerobic natural waters. Np(V), as the NpO2+ aquo and associated complexed species, is readily soluble, interacts weakly with geologic media, and has a high redox stability under a relatively wide range of subsurface conditions. These chemical properties, along with a long half-life make it a primary element of concern regarding long-term nuclear waste storage and subsurface containment. The fate and transport of neptunium in the environment may be influenced by adsorption onto bacterial surfaces. The adsorption of neptunium to bacterial surfaces ties the mobility of the contaminant to the mobility of the bacterium. In this study, the adsorption of the neptunyl (NpO2+) ion was evaluated at low ionic strength on a common soil bacterium and at high ionic strength on a halophilic bacterium isolated from a briny groundwater near the Waste Isolation Pilot Plant (WIPP) in southeast New Mexico. Adsorption experiments were performed in batch reactors as a function of pH, ionic strength, and bacteria/Np mass ratio. Np(V) adsorption was modeled using a surface complexation approach with the mathematical program FITEQL to determine functional group specific binding constants. The data from acid and base titrations of the bacteria used were also modeled to estimate the concentrations and deprotonation constants of discrete bacterial surface functional groups. Bacterial functional group characteristics and Np(V) adsorption behavior between the soil bacterium and the halophilic bacterium were compared. These results highlight key similarities and differences in actinide adsorption behavior in environments of significantly different ionic strength. The observed adsorption behavior may be linked to similarities and differences in the characteristics of the moieties between the cell walls of common gram-negative soil and halophilic bacteria. Moreover, differences in adsorption behavior may also reflect ionic

  18. Water Sorption and Radiolysis Studies for Neptunium Oxides

    Energy Technology Data Exchange (ETDEWEB)

    Icenhour, A.S.

    2004-02-03

    Plans are to convert the {sup 237}Np that is currently stored as a nitrate solution at the Savannah River Site to NpO{sub 2} and then ship it to the Y-12 National Security Complex in Oak Ridge for interim storage. This material will serve as feedstock for the {sup 238}Pu production program, and some will be periodically shipped to the Oak Ridge National Laboratory (ORNL) for fabrication into targets. The safe storage of this material requires an understanding of the radiolysis of moisture that is sorbed on the oxides, which, in turn, provides a basis for storage criteria (namely, moisture content). A two-component experimental program has been undertaken at ORNL to evaluate the radiolytic effects on NpO{sub 2}: (1) moisture uptake experiments and (2) radiolysis experiments using both gamma and alpha radiation. These experiments have produced two key results. First, the water uptake experiments demonstrated that the 0.5 wt % moisture limit that has been typically established for similar materials (e.g., uranium and plutonium oxides) cannot be obtained in a practical environment. In fact, the uptake in a typical environment can be expected to be at least an order of magnitude lower than the limit. The second key result is the establishment of steady-state pressure plateaus as a result of the radiolysis of sorbed moisture. These plateaus are the result of back reactions that limit the overall pressure increase and H{sub 2} production. These results clearly demonstrate that 0.5 wt % H{sub 2}O on NpO{sub 2} is safe for long-term storage--if such a moisture content could even be practically reached.

  19. Riverbed Clogging and Sustainability of Riverbank Filtration

    Directory of Open Access Journals (Sweden)

    Thomas Grischek

    2016-12-01

    Full Text Available Clogging refers to a reduction of riverbed hydraulic conductivity. Due to difficulties in determining the thickness of the clogging layer, the leakage coefficient (L is introduced and used to quantify the recoverable portion of bank filtrate. L was determined at several riverbank filtration (RBF sites in field tests and using an analytical solution. Results were compared with data from similar experiments in the early 1970s and 1991–1993. In the 1980s, severe river water pollution in conjunction with high water abstraction led to partly unsaturated conditions beneath the riverbed. A leakage coefficient L of 5 × 10−7 s−1 was determined. After water quality improvement, L increased to 1–1.5 × 10−6 s−1. An alternative, cost and time efficient method is presented to estimate accurate leakage coefficients. The analytical solution is based on groundwater level monitoring data from observation wells next to the river, which can later feed into numerical models. The analytical approach was able to reflect long-term changes as well as seasonal variations. Recommendations for its application are given based on experience.

  20. Sorption of cesium, radium, protactinium, uranium, neptunium and plutonium on rapakivi granite

    Energy Technology Data Exchange (ETDEWEB)

    Huitti, T.; Hakanen, M. [Helsinki Univ. (Finland). Lab. of Radiochemistry; Lindberg, A. [Geological Survey of Finland, Espoo (Finland)

    1996-12-01

    The aim of the study is to determine the sorption of cesium, radium, protactinium, uranium, neptunium and plutonium on rapakivi granite in the brackish groundwater of Haestholmen (site of the Loviisa-1, Loviisa-2 reactors). The studies were carried out under aerobic (Cs, Ra, Pa, U, Np, Pu) and anaerobic (Np, Pa, Pu, Tc) laboratory conditions. The cation exchange capasity was determined for the rock and the diffusion of tritiated water in the rocks of different degree of alteration. The sorption and diffusion properties of the rocks are briefly compared with those of host rocks at other sites under investigation by the Finnish company Posiva Oy for the final disposal of spent fuel. (29 refs.).

  1. THERMODYNAMICS OF NEPTUNIUM(V) FLOURIDE AND SULFATE AT ELEVATED TEMPERATURES

    Energy Technology Data Exchange (ETDEWEB)

    L. Rao; G. Tian; Y. Xia; J.I. Friese

    2006-03-06

    Complexation of neptunium(V) with fluoride and sulfate at elevated, temperatures was studied by microcalorimetry. Thermodynamic parameters, including the equilibrium constants and enthalpy of protonation of fluoride and sulfate, and the enthalpy of complexation between Np(V) and fluoride and sulfate at 25-70 C were determined. Results show that the complexation of Np(V) with fluoride and sulfate is endothermic and that the complexation is enhanced by the increase in temperature--a threefold increase in the stability constants of NpO{sub 2}F(aq) and NpO{sub 2}SO{sub 4}{sup -} as the temperature is increased from 25 to 70 C.

  2. Young geologist trades neptunium for newspapers as 2012 AGU Mass Media Fellow

    Science.gov (United States)

    Adams, Mary Catherine

    2012-05-01

    Though the lure of rocks, minerals, and radioactive elements took her away from her original studies, one geology Ph.D. candidate is returning to her journalism roots this summer as AGU's 2012 Mass Media Science and Engineering Fellow. Jessica Morrison is one of 12 young scientists nationwide who are trading in their lab coats for reporters' notebooks in mid-June as part of the program coordinated by the American Association for the Advancement of Science, which helps young scientists cultivate communication skills to help disseminate scientific information to general audiences. Morrison is a Ph.D. student in the Department of Civil Engineering and Geological Sciences at the University of Notre Dame. She spends her days in a laboratory investigating the geochemistry of actinides, the radioactive elements in the "no man's land" of the periodic table—the section that often gets left off or moved to the bottom. These are elements like uranium, neptunium, and plutonium.

  3. Membraneless water filtration using CO2

    Science.gov (United States)

    Shin, Sangwoo; Shardt, Orest; Warren, Patrick; Stone, Howard

    2016-11-01

    Water purification technologies such as ultrafiltration and reverse osmosis utilize porous membranes to remove suspended particles and solutes. These membranes, however, cause many drawbacks such as a high pumping cost and a need for periodic replacement due to fouling. Here we show an alternative membraneless method for separating suspended particles by exposing the colloidal suspension to CO2. Dissolution of CO2 into the suspension creates solute gradients that drive phoretic motion of particles, or so-called diffusiophoresis. Due to the large diffusion potential built up by the dissociation of carbonic acid, colloidal particles move either away from or towards the gas-liquid interface depending on their surface charge. Our findings suggest a means to separate particles without membranes or filters, thus reducing operating and maintenance costs. Using the directed motion of particles induced by exposure to CO2, we demonstrate a scalable, continuous flow, membraneless particle filtration process that exhibits very low pressure drop and is essentially free from fouling.

  4. Laboratory And Lysimeter Experimentation And Transport Modeling Of Neptunium And Strontium In Savannah River Site Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Daniel I.; Powell, B. A.; Miller, Todd J.

    2012-09-24

    The Savannah River Site (SRS) conducts performance assessment (PA) calculations to determine the appropriate amount of low-level radiological waste that can be safely disposed on site. Parameters are included in these calculations that account for the interaction between the immobile solid phase and the mobile aqueous phase. These parameters are either the distribution coefficient (K{sub d} value) or the apparent solubility value (K{sub sp}). These parameters are readily found in the literature and are used throughout the DOE complex. One shortcoming of K{sub d} values is that they are only applicable to a given set of solid and aqueous phase conditions. Therefore, a given radionuclide may have several K{sub d} values as it moves between formations and comes into contact with different solids and different aqueous phases. It is expected that the K{sub d} construct will be appropriate to use for a majority of the PA and for a majority of the radionuclides. However, semi-mechanistic models would be more representative in isolated cases where the chemistry is especially transitory or the radionuclide chemistry is especially complex, bringing to bear multiple species of varying sorption tendencies to the sediment. Semi-mechanistic models explicitly accommodate the dependency of K{sub d} values, or other sorption parameters, on contaminant concentration, competing ion concentrations, pH-dependent surface charge on the adsorbent, and solute species distribution. Incorporating semi-mechanistic concepts into geochemical models is desirable to make the models more robust and technically defensible. Furthermore, these alternative models could be used to augment or validate a Kd?based DOE Order 435.1 Performance Assessment. The objectives of this study were to: 1) develop a quantitative thermodynamically-based model for neptunium sorption to SRS sediments, and 2) determine a sorption constant from an SRS 11-year lysimeter study. The modeling studies were conducted with

  5. Laboratory And Lysimeter Experimentation And Transport Modeling Of Neptunium And Strontium In Savannah River Site Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Daniel I.; Powell, B. A.; Miller, Todd J.

    2012-09-24

    The Savannah River Site (SRS) conducts performance assessment (PA) calculations to determine the appropriate amount of low-level radiological waste that can be safely disposed on site. Parameters are included in these calculations that account for the interaction between the immobile solid phase and the mobile aqueous phase. These parameters are either the distribution coefficient (K{sub d} value) or the apparent solubility value (K{sub sp}). These parameters are readily found in the literature and are used throughout the DOE complex. One shortcoming of K{sub d} values is that they are only applicable to a given set of solid and aqueous phase conditions. Therefore, a given radionuclide may have several K{sub d} values as it moves between formations and comes into contact with different solids and different aqueous phases. It is expected that the K{sub d} construct will be appropriate to use for a majority of the PA and for a majority of the radionuclides. However, semi-mechanistic models would be more representative in isolated cases where the chemistry is especially transitory or the radionuclide chemistry is especially complex, bringing to bear multiple species of varying sorption tendencies to the sediment. Semi-mechanistic models explicitly accommodate the dependency of K{sub d} values, or other sorption parameters, on contaminant concentration, competing ion concentrations, pH-dependent surface charge on the adsorbent, and solute species distribution. Incorporating semi-mechanistic concepts into geochemical models is desirable to make the models more robust and technically defensible. Furthermore, these alternative models could be used to augment or validate a Kd?based DOE Order 435.1 Performance Assessment. The objectives of this study were to: 1) develop a quantitative thermodynamically-based model for neptunium sorption to SRS sediments, and 2) determine a sorption constant from an SRS 11-year lysimeter study. The modeling studies were conducted with

  6. Cake creep during filtration of flocculated manure

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Keiding, Kristian

    the distribution of N and P on the fields. Filtration is a useful method for such a separation. Furthermore, chemicals can be added to flocculate the solids and thereby increase the filterability i.e. the specific filter-cake resistance can be reduced from 1015 m/kg to 1011 m/kg. Both the amount of added chemicals......, and the mixing procedure affect the result, and lab-scale experiments are often used to study how these pre-treatments influence the filtration process. However, the existing mathematical filtration models are based on filtration of inorganic particles and cannot simulate the filtration data obtained when manure...... that the discrepancy between the filtration theory and the observed filtration behaviour is due to a time-dependent collapse of the formed cake (creep). This can also explain the observed behaviour when flocculated manure is filtered. The filtration data can be simulated if cake creep is adopted in the filtration...

  7. Depot effect of bioactive components in experimental membrane filtrations

    Science.gov (United States)

    Mitev, D.; Peshev, D.; Peev, G.; Peeva, L.

    2017-01-01

    Depot effects were found to be accompanying phenomena of membrane separation processes. Accumulation of target species in the membrane matrix during feasibility tests can hamper proper conclusions or compromise the filtration results. Therefore, we investigated the effects of delayed membrane release of chlorogenic acid and caffeine, considered as key compounds of interest in spent coffee products’ recovery treatment. Permeate fluxes and key components release were studied in course of 24 hours via nanofiltration of pure solvent, both immediately after the mock solution filtration and after idle stay. Conclusions are drawn and recommendations advised for proper analysis of experimental data on membrane screening.

  8. Filtration ATF in automatic transmissions (AT of cars

    Directory of Open Access Journals (Sweden)

    Tadeusz Dziubak

    2014-03-01

    Full Text Available Functions and conditions of work of suction ATF filters are presented. Requirements ofATF filters are discussed. Sources of contaminations ATF are presented. ATF filtration system wascharacterized. Classification of ATF filters and their selection of design solutions are presented. Filtermaterials used for the production of ATF suction filters are presented and characterized. Conditions ofthe work of suction ATF filters were analyzed. Hydraulic and filtration characteristics are discussed.[b]Keywords: AT[/b] — automatic transmissions, ATF — automatic transmission fluid, ATF filter

  9. Radioactive waste forms stabilized by ChemChar gasification: characterization and leaching behavior of cerium, thorium, protactinium, uranium, and neptunium.

    Science.gov (United States)

    Marrero, T W; Morris, J S; Manahan, S E

    2004-02-01

    The uses of a thermally reductive gasification process in conjunction with vitrification and cementation for the long-term disposal of low level radioactive materials have been investigated. gamma-ray spectroscopy was used for analysis of carrier-free protactinium-233 and neptunium-239 and a stoichiometric amount of cerium (observed cerium-141) subsequent to gasification and leaching, up to 48 days. High resolution ICP-MS was used to analyze the cerium, thorium, and uranium from 46 to 438 days of leaching. Leaching procedures followed the guidance of ASTM Procedure C 1220-92, Standard Test Method for Static Leaching of Monolithic Waste Forms for Disposal of Radioactive Waste. The combination of the thermally reductive pretreatment, vitrification and cementation produced a highly non-leachable form suitable for long-term disposal of cerium, thorium, protactinium, uranium, and neptunium.

  10. Improving IAQ Via Air Filtration.

    Science.gov (United States)

    Monk, Brian

    1999-01-01

    Provides tips on using air filtration to control indoor air quality in educational facilities, including dedicated spaces with unique air quality conditions such as in libraries, museums and archival storage areas, kitchens and dining areas, and laboratories. The control of particulate contaminants, gaseous contaminants, and moisture buildup are…

  11. Filtration combustion: Smoldering and SHS

    Science.gov (United States)

    Matkowsky, Bernard J.

    1995-01-01

    Smolder waves and SHS (self-propagating high-temperature synthesis) waves are both examples of combustion waves propagating in porous media. When delivery of reactants through the pores to the reaction site is an important aspect of the process, it is referred to as filtration combustion. The two types of filtration combustion have a similar mathematical formulation, describing the ignition, propagation and extinction of combustion waves in porous media. The goal in each case, however, is different. In smoldering the desired goal is to prevent propagation, whereas in SHS the goal is to insure propagation of the combustion wave, leading to the synthesis of desired products. In addition, the scales in the two areas of application may well differ. For example, smoldering generally occurs at a relatively low temperature and with a smaller propagation velocity than SHS filtration combustion waves. Nevertheless, the two areas of application have much in common, so that mechanisms learned about in one application can be used to advantage in the other. In this paper we discuss recent results in the areas of filtration combustion.

  12. Demonstration of creep during filtration

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Bugge, Thomas Vistisen; Kirchheiner, Anders Løvenbalk

    The classical filtration theory assumes a unique relationship between the local filter cake porosity and the local effective pressure. For a number of compressible materials, it has however been observed that during the consolidation stage this may not be the case. It has been found that the prod......The classical filtration theory assumes a unique relationship between the local filter cake porosity and the local effective pressure. For a number of compressible materials, it has however been observed that during the consolidation stage this may not be the case. It has been found...... that the production of filtrate also depends on the characteristic time for the filter cake solids to deform. This is formulated in the Terzaghi-Voigt model in which a secondary consolidation is introduced. The secondary consolidation may be visualized by plots of the relative cake deformation (U) v.s. the square...... magnitude as the primary consolidation (defined by the hydraulic retardation), the creep phenomenon may occur during filtration. This will lead to Ruth's plots characterized by a concave with two (more or less) distinct slopes. The slopes are defined by the relationship between the porosity...

  13. Modelling contaminant transport for pumping wells in riverbank filtration systems.

    Science.gov (United States)

    Mustafa, Shaymaa; Bahar, Arifah; Aziz, Zainal Abdul; Suratman, Saim

    2016-01-01

    Analytical study of the influence of both the pumping well discharge rate and pumping time on contaminant transport and attenuation is significant for hydrological and environmental science applications. This article provides an analytical solution for investigating the influence of both pumping time and travelling time together for one-dimensional contaminant transport in riverbank filtration systems by using the Green's function approach. The basic aim of the model is to understand how the pumping time and pumping rate, which control the travelling time, can affect the contaminant concentration in riverbank filtration systems. Results of analytical solutions are compared with the results obtained using a MODFLOW numerical model. Graphically, it is found that both analytical and numerical solutions have almost the same behaviour. Additionally, the graphs indicate that any increase in the pumping rate or simulation pumping time should increase the contamination in groundwater. The results from the proposed analytical model are well matched with the data collected from a riverbank filtration site in France. After this validation, the model is then applied to the first pilot project of a riverbank filtration system conducted in Malaysia. Sensitivity analysis results highlight the importance of degradation rates of contaminants on groundwater quality, for which higher utilization rates lead to the faster consumption of pollutants. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Perlite filtration of phenolic compounds from cigarette smoke.

    Science.gov (United States)

    Rostami-Charati, Faramarz; Robati, Gholamreza Moradi; Naghizadeh, Farhad; Hosseini, Shahnaz; Chaichi, Mohammad Javad

    2013-01-01

    Adsorption of phenolic compounds and chemical analysis of them from a local production cigarette (named by Farvardin cigarette) smoke have been investigated by using perlite filtration. In this research, the mainstream smoke was tested by three filtration methods: Perlite filter, Cambridge filter and general cigarette filter. Then the used filter was extracted by pure methanol as solvent. After that, the extracted solution was analysed by GC-MS. By this consideration, the phenolic derivatives such as phenol, hydroquinone, resorcinol, pyrocatechol, m-cresol, p-cresol and o-cresol were detected. The structure of the perlite filtration after absorption was studied by SEM. In addition, its chemical structure was investigated by XRD and XRF.

  15. EVALUATION OF EFFECTIVENESS OF HOUSEHOLD DRINKING WATER FILTRATION

    Directory of Open Access Journals (Sweden)

    Karolina Jezierska

    2014-10-01

    Full Text Available The aim of this study was to analyze the effectiveness of household drinking water filtration. This article demonstrates the possibilities of using study on the reaction of ascorbic acid degradation in aqueous solutions to develop a new method for determining the effectiveness of household drinking water filtration. Based on the measurements of absorbance of ascorbic acid a new parameters WCW (Coeffi cient of Water Purity and SF (Filtration Degree were defined. Correlations between the SF and the amount of filtered water (filter usage were investigated. With the filter usage decreasing effectiveness of calcium ions removal and drop of differences in conductivity between the tap and filtered water were observed. SF decreases proportionally to the filter usage and therefore the proposed method can be an effective tool to determine the effectiveness of domestic water filters.

  16. Filtration Understanding: FY10 Testing Results and Filtration Model Update

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, Richard C.; Billing, Justin M.; Burns, Carolyn A.; Peterson, Reid A.; Russell, Renee L.; Schonewill, Philip P.; Shimskey, Rick W.

    2011-04-04

    This document completes the requirements of Milestone 2-4, Final Report of FY10 Testing, discussed in the scope of work outlined in the EM31 task plan WP-2.3.6-2010-1. The focus of task WP 2.3.6 is to improve the U.S. Department of Energy’s (DOE’s) understanding of filtration operations for high-level waste (HLW) to improve filtration and cleaning efficiencies, thereby increasing process throughput and reducing the Na demand (through acid neutralization). Developing the cleaning/backpulsing requirements will produce much more efficient operations for both the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and the Savannah River Site (SRS), thereby significantly increasing throughput by limiting cleaning cycles. The scope of this work is to develop the understanding of filter fouling to allow developing this cleaning/backpulsing strategy.

  17. 40 CFR 141.173 - Filtration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Filtration. 141.173 Section 141.173... PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving 10,000 or More People § 141.173 Filtration. A public water system subject to the requirements of this subpart that...

  18. SOLUTIONING

    Directory of Open Access Journals (Sweden)

    Maria de Hoyos Guajardo, Ph.D. Candidate, M.Sc., B.Eng.

    2004-11-01

    Full Text Available The theory that is presented below aims to conceptualise how a group of undergraduate students tackle non-routine mathematical problems during a problem-solving course. The aim of the course is to allow students to experience mathematics as a creative process and to reflect on their own experience. During the course, students are required to produce a written ‘rubric’ of their work, i.e., to document their thoughts as they occur as well as their emotionsduring the process. These ‘rubrics’ were used as the main source of data.Students’ problem-solving processes can be explained as a three-stage process that has been called ‘solutioning’. This process is presented in the six sections below. The first three refer to a common area of concern that can be called‘generating knowledge’. In this way, generating knowledge also includes issues related to ‘key ideas’ and ‘gaining understanding’. The third and the fourth sections refer to ‘generating’ and ‘validating a solution’, respectively. Finally, once solutions are generated and validated, students usually try to improve them further before presenting them as final results. Thus, the last section deals with‘improving a solution’. Although not all students go through all of the stages, it may be said that ‘solutioning’ considers students’ main concerns as they tackle non-routine mathematical problems.

  19. Mobile surface water filtration system

    Directory of Open Access Journals (Sweden)

    Aashish Vatsyayan

    2012-09-01

    Full Text Available To design a mobile system for surface water filtrationMethodology: the filtration of surface impurities begins with their retraction to concentrated thickness using non ionising surfactants, then isolation using surface tension property and sedimentation of impurities in process chamber using electrocoagulation. Result:following studies done to determine the rate of spreading of crude oil on water a method for retraction of spread crude oil to concentrated volumes is developed involving addition of non -ionising surfactants in contrast to use of dispersants. Electrocoagulation process involves multiple processes taking place to lead to depositionof impurities such as oil, grease, metals. Studies of experiments conducted reveals parameters necessary for design of electrocoagulation process chamber though a holistic approach towards system designing is still required. Propeller theory is used in determining the required design of propeller and the desired thrust, the overall structure will finally contribute in deciding the choice of propeller.

  20. Pathogen filtration to control plant disease outbreak in greenhouse production

    Science.gov (United States)

    Jeon, Sangho; Krasnow, Charles; Bhalsod, Gemini; Granke, Leah; Harlan, Blair; Hausbeck, Mary; Zhang, Wei

    2016-04-01

    Previous research has been extensively focused on understanding the fate and transport of human microbial pathogens in soil and water environments. However, little is known about the transport of plant pathogens, although these pathogens are often found in irrigation waters and could cause severe crop damage and economical loss. Water mold pathogens including Phytophthora spp. and Pythium spp. are infective to a wide range of vegetable and floriculture crops, and they are primarily harbored in soils and disseminated through water flow. It is challenging to control these pathogens because they often quickly develop resistance to many fungicides. Therefore, this multi-scale study aimed to investigate physical removal of plant pathogens from water by filtration, thus reducing the pathogen exposure risks to crops. In column-scale experiments, we studied controlling factors on the transport and retention of Phytophthora capsici zoospores in saturated columns packed with iron oxide coated-sand and uncoated-sand under varying solution chemistry. Biflagellate zoospores were less retained than encysted zoospores, and lower solution pH and greater iron oxide content increased the retention of encysted zoospores. These results provided insights on environmental dispersal of Phytophthora zoospores in natural soils as well as on developing cost-effective engineered filtration systems for pathogen removal. Using small-scale greenhouse filtration systems, we further investigated the performance of varying filter media (i.e., granular sand, iron oxide coated ceramic porous media, and activated carbon) in mitigating disease outbreaks of Phytophthora and Pythium for greenhouse-grown squash and poinsettia, respectively, in comparison with fungicide treatment. For squash, filtration by iron oxide coated media was more effective in reducing the Phytophthora infection, comparing to sand filtration and fungicide application. For poinsettia, sand filtration performed better in controlling

  1. ACTINIDE REMOVAL PROCESS SAMPLE ANALYSIS, CHEMICAL MODELING, AND FILTRATION EVALUATION

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C.; Herman, D.; Pike, J.; Peters, T.

    2014-06-05

    Filtration within the Actinide Removal Process (ARP) currently limits the throughput in interim salt processing at the Savannah River Site. In this process, batches of salt solution with Monosodium Titanate (MST) sorbent are concentrated by crossflow filtration. The filtrate is subsequently processed to remove cesium in the Modular Caustic Side Solvent Extraction Unit (MCU) followed by disposal in saltstone grout. The concentrated MST slurry is washed and sent to the Defense Waste Processing Facility (DWPF) for vitrification. During recent ARP processing, there has been a degradation of filter performance manifested as the inability to maintain high filtrate flux throughout a multi-batch cycle. The objectives of this effort were to characterize the feed streams, to determine if solids (in addition to MST) are precipitating and causing the degraded performance of the filters, and to assess the particle size and rheological data to address potential filtration impacts. Equilibrium modelling with OLI Analyzer{sup TM} and OLI ESP{sup TM} was performed to determine chemical components at risk of precipitation and to simulate the ARP process. The performance of ARP filtration was evaluated to review potential causes of the observed filter behavior. Task activities for this study included extensive physical and chemical analysis of samples from the Late Wash Pump Tank (LWPT) and the Late Wash Hold Tank (LWHT) within ARP as well as samples of the tank farm feed from Tank 49H. The samples from the LWPT and LWHT were obtained from several stages of processing of Salt Batch 6D, Cycle 6, Batch 16.

  2. In-Water Hull Cleaning & Filtration System

    Science.gov (United States)

    George, Dan

    2015-04-01

    Dan George R & D Mining Technology LinkedIn GRD Franmarine have received the following prestigious awards in 2014 for their research & development of an in-water hull cleaning and filtration system "The Envirocart: Golden Gecko Award for Environmental Excellence; WA Innovator of the Year - Growth Sector; Department of Fisheries - Excellence in Marine Biosecurity Award - Innovation Category; Lloyd's List Asia Awards - Environmental Award; The Australian Innovation Challenge - Environment, Agriculture and Food Category; and Australian Shipping and Maritime Industry Award - Environmental Transport Award. The Envirocart developed and patented by GRD Franmarine is a revolutionary new fully enclosed capture and containment in-water hull cleaning technology. The Envirocart enables soft Silicon based antifouling paints and coatings containing pesticides such as Copper Oxide to be cleaned in situ using a contactless cleaning method. This fully containerised system is now capable of being deployed to remote locations or directly onto a Dive Support Vessel and is rated to offshore specifications. This is the only known method of in-water hull cleaning that complies with the Department of Agriculture Fisheries and Forestry (DAFF) and Department of Fisheries WA (DoF) Guidelines. The primary underwater cleaning tool is a hydraulically powered hull cleaning unit fitted with rotating discs. The discs can be fitted with conventional brushes for glass or epoxy based coatings or a revolutionary new patented blade system which can remove marine biofouling without damaging the antifouling paint (silicone and copper oxide). Additionally there are a patented range of fully enclosed hand cleaning tools for difficult to access niche areas such as anodes and sea chests, providing an innovative total solution that enables in-water cleaning to be conducted in a manner that causes no biological risk to the environment. In full containment mode or when AIS are present, material is pumped

  3. Measurement of water filtration in skeletal muscle in man by an osmotic transient method

    DEFF Research Database (Denmark)

    Palm, T; Nielsen, S L; Lassen, N A

    1983-01-01

    Water filtration in the human forearm was determined with a new method using a hyperoncotic transient of albumin solution infused into the brachial artery. Baseline dilution of labelled albumin in deep forearm vein plasma in excess of the contribution from arterial blood and from infusate...... was assumed to originate from extravascular water filtered into the blood by the transient. The filtration coefficient (Fc) was determined as the ratio between filtered water and increase in colloid osmotic pressure in the blood samples, and gives the filtrative water permeability in the exchange areas...... of the microcirculation. In 10 normal volunteers, Fc was 0.00082 ml (ml mmHg)-1 (SD=0.00007). Multiplication of Fc by plasma flow in the forearm gave a filtration capacity (Kf) of 0.0036 ml (100 ml tissue min mmHg)-1 (SD=0.00137). This filtration capacity (Kf) represents that of fast flowing regions in the forearm...

  4. Water Filtration Using Plant Xylem

    CERN Document Server

    Lee, Jongho; Chambers, Valerie; Venkatesh, Varsha; Karnik, Rohit

    2013-01-01

    Effective point-of-use devices for providing safe drinking water are urgently needed to reduce the global burden of waterborne disease. Here we show that plant xylem from the sapwood of coniferous trees - a readily available, inexpensive, biodegradable, and disposable material - can remove bacteria from water by simple pressure-driven filtration. Approximately 3 cm3 of sapwood can filter water at the rate of several liters per day, sufficient to meet the clean drinking water needs of one person. The results demonstrate the potential of plant xylem to address the need for pathogen-free drinking water in developing countries and resource-limited settings.

  5. Superamphiphobic nanofibrous membranes for effective filtration of fine particles.

    Science.gov (United States)

    Wang, Na; Zhu, Zhigao; Sheng, Junlu; Al-Deyab, Salem S; Yu, Jianyong; Ding, Bin

    2014-08-15

    The worldwide demands are rising for an energy-efficient and cost-effective approach that can provide advanced nanofibrous membranes with high filtration performance and superior antifouling properties. Here we report a novel synthesized fluorinated polyurethane (FPU) modified nanofibrous membrane optimized to achieve oil and non-oil aerosol particle filtration. By employing the FPU incorporation, the polyacrylonitrile/polyurethane (PAN/PU) composite membranes were endowed with superhydrophobicity with a water contact angle of 154° and superoleophobicity with an oil contact angle of 151°. Morphology, surface wettability, porous structure, and filtration performance could be manipulated by tuning the solution composition as well as the hierarchical structure. Furthermore, the as-prepared membranes can capture, for the first time, a range of different oil aerosol particles in a single-unit operation, with >99.9% filtration efficiency, by using the combined contribution of fiber diameter and surface roughness acting on the objective particles. Exemplified here by the construction of superamphiphobic nanofibrous membrane, numerous applications of this medium includes high efficiency particulate air filters, ultra-low penetration air filters, and respiratory protection equipment.

  6. Membrane filters and membrane-filtration processes for health care.

    Science.gov (United States)

    Eudailey, W A

    1983-11-01

    The development of membrane-filtration processes is reviewed, and current types and uses of membrane filtration in health care is discussed. Development of adequate support structures for filters and of disposable filtration devices has facilitated development of filtration processes for pharmaceutical industry, manufacturing in hospital pharmacies, and direct patient care. Hydrophobic filters have also been developed; aqueous solutions cannot wet the pore structures of these filters and therefore cannot pass. Sterility-testing systems have also been developed. There are two types of filters: depth (constructed of compacted fibers) and membrane (which have a homogeneous internal structure). Depth filters retain only a portion of particles in a particular size range and are generally not acceptable for use in health care. Membrane filters retain all particles of a given size. Types of membrane filters are selected for specific uses based on needed flow rates, particulate load, and retention capability. Membrane filters may be validated using bacterial-passage, bubble-point, and diffusion tests. Most membrane filters used in health care are microporous filters that retain particles in the 0.1-10-micron size range. Applications are currently being developed for ultrafilters, which retain both particles and substances with large molecular structures such as proteins, and reverse-osmosis filter membranes, which allow only water or water-miscible solvents of very low molecular weights to pass. Experience in engineering designs, quality assurance, and test procedures has led to the development of many safe, reliable, and effective membrane products for health care.

  7. Pig manure treatment and purification by filtration.

    Science.gov (United States)

    Makara, A; Kowalski, Z

    2015-09-15

    This study aimed to develop a new, complex pig manure treatment and filtration process. The final scheme, called the AMAK process, comprised the following successive steps: mineralization with mineral acids, alkalization with lime milk, superphosphate addition, a second alkalization, thermal treatment, and pressure filtration. The proposed method produced a filtrate with 95%, 80%, and 96% reductions in chemical oxygen demand, nitrogen content, and phosphorus content, respectively. An advantage of the proposed method was that it incorporated a crystalline phase into the solid organic part of the manure, which enabled high filtration rates (>1000 kg m(-2) h(-1)) and efficient separation. The process also eliminated odor emissions from the filtrate and sediment. The treated filtrate could be used to irrigate crops or it could be further treated in conventional biological wastewater treatment plants. The sediment could be used for producing mineral-organic fertilizer. The AMAK process is inexpensive, and it requires low investment costs.

  8. Side Stream Filtration for Cooling Towers

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-10-20

    This technology evaluation assesses side stream filtration options for cooling towers, with an objective to assess key attributes that optimize energy and water savings along with providing information on specific technology and implementation options. This information can be used to assist Federal sites to determine which options may be most appropriate for their applications. This evaluation provides an overview of the characterization of side stream filtration technology, describes typical applications, and details specific types of filtration technology.

  9. Glomerular Filtration Barrier Assembly: An insight

    OpenAIRE

    Arif, Ehtesham; Nihalani, Deepak

    2013-01-01

    A glomerulus is the network of capillaries that resides in the Bowman’s capsule that functions as a filtration unit of kidney. The glomerular function ensures that essential plasma proteins are retained in blood and the filtrate is passed on as urine. The glomerular filtration assembly is composed of three main cellular barriers that are critical for the ultrafiltration process, the fenestrated endothelium, glomerular basement membrane and highly specialized podocytes. The podocytes along wit...

  10. Persistent homology in graph power filtrations.

    Science.gov (United States)

    Parks, Allen D; Marchette, David J

    2016-10-01

    The persistence of homological features in simplicial complex representations of big datasets in R (n) resulting from Vietoris-Rips or Čech filtrations is commonly used to probe the topological structure of such datasets. In this paper, the notion of homological persistence in simplicial complexes obtained from power filtrations of graphs is introduced. Specifically, the rth complex, r ≥ 1, in such a power filtration is the clique complex of the rth power G(r) of a simple graph G. Because the graph distance in G is the relevant proximity parameter, unlike a Euclidean filtration of a dataset where regional scale differences can be an issue, persistence in power filtrations provides a scale-free insight into the topology of G. It is shown that for a power filtration of G, the girth of G defines an r range over which the homology of the complexes in the filtration are guaranteed to persist in all dimensions. The role of chordal graphs as trivial homology delimiters in power filtrations is also discussed and the related notions of 'persistent triviality', 'transient noise' and 'persistent periodicity' in power filtrations are introduced.

  11. Air filtration and indoor air quality

    DEFF Research Database (Denmark)

    Bekö, Gabriel

    2006-01-01

    decent ventilation and air cleaning/air filtration, high indoor air quality cannot be accomplished. The need for effective air filtration has increased with increasing evidence on the hazardous effects of fine particles. Moreover, the air contains gaseous pollutants, removal of which requires various air....... These contradictions should motivate manufacturers and researchers to develop new efficient filtration techniques and/or improve the existing ones. Development of low polluting filtration techniques, which are at the same time easy and inexpensive to maintain is the way forward in the future....

  12. Atlas of Atomic Spectral Lines of Neptunium Emitted by Inductively Coupled Plasma

    Energy Technology Data Exchange (ETDEWEB)

    DeKalb, E.L. and Edelson, M. C.

    1987-08-01

    Optical emission spectra from high-purity Np-237 were generated with a glovebox-enclosed inductively coupled plasma (ICP) source. Spectra covering the 230-700 nm wavelength range are presented along with general commentary on the methodology used in collecting the data. The Ames Laboratory Nuclear Safeguards and Security Program has been charged with the task of developing optical spectroscopic methods to analyze the composition of spent nuclear fuels. Such materials are highly radioactive even after prolonged 'cooling' and are chemically complex. Neptunium (Np) is a highly toxic by-product of nuclear power generation and is found, in low abundance, in spent nuclear fuels. This atlas of the optical emission spectrum of Np, as produced by an inductively coupled plasma (ICP) spectroscopic source, is part of a general survey of the ICP emission spectra of the actinide elements. The ICP emission spectrum of the actinides originates almost exclusively from the electronic relaxation of excited, singly ionized species. Spectral data on the Np ion emission spectrum (i.e., the Np II spectrum) have been reported by Tomkins and Fred [1] and Haaland [2]. Tomkins and Fred excited the Np II spectrum with a Cu spark discharge and identified 114 Np lines in the 265.5 - 436.3 nm spectral range. Haaland, who corrected some spectral line misidentifications in the work of Tomkins and Fred, utilized an enclosed Au spark discharge to excite the Np II spectrum and reported 203 Np lines within the 265.4 - 461.0 nm wavelength range.

  13. Quantum chemistry study of uranium(VI), neptunium(V), and plutonium(IV,VI) complexes with preorganized tetradentate phenanthrolineamide ligands.

    Science.gov (United States)

    Xiao, Cheng-Liang; Wu, Qun-Yan; Wang, Cong-Zhi; Zhao, Yu-Liang; Chai, Zhi-Fang; Shi, Wei-Qun

    2014-10-20

    The preorganized tetradentate 2,9-diamido-1,10-phenanthroline ligand with hard-soft donors combined in the same molecule has been found to possess high selectivity toward actinides in an acidic aqueous solution. In this work, density functional theory (DFT) coupled with the quasi-relativistic small-core pseudopotential method was used to investigate the structures, bonding nature, and thermodynamic behavior of uranium(VI), neptunium(V), and plutonium(IV,VI) with phenanthrolineamides. Theoretical optimization shows that Et-Tol-DAPhen and Et-Et-DAPhen ligands are both coordinated with actinides in a tetradentate chelating mode through two N donors of the phenanthroline moiety and two O donors of the amide moieties. It is found that [AnO2L(NO3)](n+) (An = U(VI), Np(V), Pu(VI); n = 0, 1) and PuL(NO3)4 are the main 1:1 complexes. With respect to 1:2 complexes, the reaction [Pu(H2O)9](4+)(aq) + 2L(org) + 2NO3(-)(aq) → [PuL2(NO3)2](2+)(org) + 9H2O(aq) might be another probable extraction mechanism for Pu(IV). From the viewpoint of energy, the phenanthrolineamides extract actinides in the order of Pu(IV) > U(VI) > Pu(VI) > Np(V), which agrees well with the experimental results. Additionally, all of the thermodynamic reactions are more energetically favorable for the Et-Tol-DAPhen ligand than the Et-Et-DAPhen ligand, indicating that substitution of one ethyl group with one tolyl group can enhance the complexation abilities toward actinide cations (anomalous aryl strengthening).

  14. Tangential flow filtration of hemoglobin.

    Science.gov (United States)

    Palmer, Andre F; Sun, Guoyong; Harris, David R

    2009-01-01

    Bovine and human hemoglobin (bHb and hHb, respectively) was purified from bovine and human red blood cells via tangential flow filtration (TFF) in four successive stages. TFF is a fast and simple method to purify Hb from RBCs using filtration through hollow fiber (HF) membranes. Most of the Hb was retained in stage III (100 kDa HF membrane) and displayed methemoglobin levels less than 1%, yielding final concentrations of 318 and 300 mg/mL for bHb and hHb, respectively. Purified Hb exhibited much lower endotoxin levels than their respective RBCs. The purity of Hb was initially assessed via SDS-PAGE, and showed tiny impurity bands for the stage III retentate. The oxygen affinity (P(50)) and cooperativity coefficient (n) were regressed from the measured oxygen-RBC/Hb equilibrium curves of RBCs and purified Hb. These results suggest that TFF yielded oxygen affinities of bHb and hHb that are comparable to values in the literature. LC-MS was used to measure the molecular weight of the alpha (alpha) and beta (beta) globin chains of purified Hb. No impurity peaks were present in the HPLC chromatograms of purified Hb. The mass of the molecular ions corresponding to the alpha and beta globin chains agreed well with the calculated theoretical mass of the alpha- and beta- globin chains. Taken together, our results demonstrate that HPLC-grade Hb can be generated via TFF. In general, this method can be more broadly applied to purify Hb from any source of RBCs. This work is significant, since it outlines a simple method for generating Hb for synthesis and/or formulation of Hb-based oxygen carriers.

  15. Rapid and simultaneous determination of neptunium and plutonium isotopes in environmental samples by extraction chromatography using sequential injection analysis and ICP-MS

    DEFF Research Database (Denmark)

    Qiao, Jixin; Hou, Xiaolin; Roos, Per

    2010-01-01

    This paper reports an automated analytical method for rapid and simultaneous determination of plutonium isotopes (239Pu and 240Pu) and neptunium (237Np) in environmental samples. An extraction chromatographic column packed with TrisKem TEVA® resin was incorporated in a sequential injection (SI...

  16. Carbon Nanotube Membranes: Synthesis, Properties, and Future Filtration Applications

    Science.gov (United States)

    Rashid, Md. Harun-Or; Ralph, Stephen F.

    2017-01-01

    Over the course of the past decade, there has been growing interest in the development of different types of membranes composed of carbon nanotubes (CNTs), including buckypapers and composite materials, for an ever-widening range of filtration applications. This article provides an overview of how different types of CNT membranes are prepared and the results obtained from investigations into their suitability for different applications. The latter involve the removal of small particles from air samples, the filtration of aqueous solutions containing organic compounds and/or bacteria, and the separation of individual liquids present in mixtures. A growing number of reports have demonstrated that the incorporation of CNTs into composite membranes confers an improved resistance to fouling caused by biomacromolecules and bacteria. These results are discussed, along with evidence that demonstrates it is possible to further reduce fouling by taking advantage of the inherent conductivity of composite membranes containing CNTs, as well as by using different types of electrochemical stimuli. PMID:28468314

  17. Formation of siliceous sediments in brandy after diatomite filtration.

    Science.gov (United States)

    Gómez, J; Gil, M L A; de la Rosa-Fox, N; Alguacil, M

    2015-03-01

    Brandy is quite a stable spirit but sometimes light sediment appears. This sediment was separated and analysed by IR and SEM-EDX. It was revealed that the sediment is composed mostly of silica and residual organic matter. Silica was present as an amorphous phase and as microparticles. In an attempt to reproduce the formation of the sediment, a diatomite extract was prepared with an ethanol/water mixture (36% vol.) and a calcined diatomite similar to that used in brandy filtration. This extract was added to unfiltered brandy in different amounts. After 1 month, the Si concentration decreased in all samples and sediments with similar compositions and features to those found in the unstable brandy appeared. The amounts of sediment obtained were directly related to the decrease in Si concentration in solution. Consequently, it can be concluded that siliceous sediment in brandy originates from Si released during diatomite filtration. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Crosslinked polytriazole membranes for organophilic filtration

    KAUST Repository

    Chisca, Stefan

    2016-12-30

    We report the preparation of crosslinked membranes for organophilic filtration, by reacting a new polytriazole with free OH groups, using non-toxic poly (ethylene glycol) diglycidyl ether (PEGDE). The OH-functionalized polymer was obtained by converting the oxadiazole to triazole rings with high yield (98%). The maximum degree of crosslinking is achieved after 6 h of reaction. The crosslinked polytriazole membranes are stable in a wide range of organic solvents and show high creep recovery, indicating the robustness of crosslinked membranes. The influence of different casting solutions and different crosslinking time on the membrane morphology and membrane performance was investigated. The membranes performance was studied in dimethylformamide (DMF) and (tetrahydrofuran) THF. We achieved a permeance for THF of 49 L m−2 h−1 bar−1 for membranes with molecular weight cut off (MWCO) of 7 kg mol−1 and a permeance for THF of 17.5 L m−2 h−1 bar−1 for membranes with MWCO of 3 kg mol−1. Our data indicate that by using the new polytriazole is possible to adjust the pore dimensions of the membranes to have a MWCO, which covers ultra- and nanofiltration range.

  19. Zirconium/PVA modified flat-sheet PVDF membrane as a cost-effective adsorptive and filtration material: A case study on decontamination of organic arsenic in aqueous solutions.

    Science.gov (United States)

    Zhao, Dandan; Yu, Yang; Wang, Chenghong; Chen, J Paul

    2016-09-01

    Organic arsenic in waters has been a global concern in drinking water due to its higher toxicity to humans. In this study, a novel zirconium/polyvinyl alcohol (PVA) modified polyvinylidene fluoride (PVDF) membrane was applied to remove organic arsenic from water. The impregnation of zirconium ions within the modified membrane was attributed to the coordination reactions among the zirconium ions, ether and hydroxyl groups. The synthesized membrane worked better at the acidic conditions and achieved the optimal uptake for both monomethylarsonic (MMA) and dimethylarsinic (DMA) at pH 2.0. The adsorption isotherm study demonstrated that the adsorption of both organic arsenic species was controlled by the mono-layer adsorption process; the maximum adsorption capacities for MMA and DMA were 73.04 and 37.53mg/g at pH 2, and 29.78 and 19.03mg/g at pH 7.0, respectively. The presence of humic acid had a negligible impact on the uptake of organic arsenic, whereas varying impacts on the arsenic adsorption were observed due to the presence of coexisting anions such as fluoride, phosphate, carbonate and silicate. A single piece of membrane with a surface area of only 12.56cm(2) could treat 7.5-L MMA and 4.1-L DMA solution with an influent concentration of about 100μg/L to meet the WHO and USEPA standard of 10μg/L. Based on the XPS analyses, the ion exchange reaction between chloride ions on the membrane surface and organic arsenic species was responsible for the removal of both MMA and DMA. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Evaluation of emerging factors blocking filtration of high-adjunct-ratio wort.

    Science.gov (United States)

    Ma, Ting; Zhu, Linjiang; Zheng, Feiyun; Li, Yongxian; Li, Qi

    2014-08-20

    Corn starch has become a common adjunct for beer brewing in Chinese breweries. However, with increasing ratio of corn starch, problems like poor wort filtration performance arise, which will decrease production capacity of breweries. To solve this problem, factors affecting wort filtration were evaluated, such as the size of corn starch particle, special yellow floats formed during liquefaction of corn starch, and residual substance after liquefaction. The effects of different enzyme preparations including β-amylase and β-glucanase on filtration rate were also evaluated. The results indicate that the emerging yellow floats do not severely block filtration, while the fine and uniform-shape corn starch particle and its incompletely hydrolyzed residue after liquefaction are responsible for filtration blocking. Application of β-amylase preparation increased the filtration rate of liquefied corn starch. This study is useful for our insight into the filtration blocking problem arising in the process of high-adjunct-ratio beer brewing and also provides a feasible solution using enzyme preparations.

  1. Filtration performance of microporous ceramic supports.

    Science.gov (United States)

    Belouatek, Aissa; Ouagued, Abdellah; Belhakem, Mustapha; Addou, Ahmed

    2008-04-24

    The use of inorganic membranes in pollution treatment is actually limited by the cost of such membranes. Advantages of inorganic membranes are their chemical, thermal and pH properties. The purpose of this work was the development of microporous ceramic materials based on clay for liquid waste processing. The supports or ceramic filters having various compositions were prepared and thermally treated at 1100 degrees C. The results show that, at the temperature studied, porosity varied according to the support composition from 12% for the double-layered (ceramic) support to 47% for the activated carbon- filled support with a mean pore diameter between 0.8 and 1.3 microm, respectively. Volumes of 5 l of distilled water were filtered tangentially for 3 h under an applied pressure of 3.5 and 5.5 bar. The retention of tubular supports prepared was tested with molecules of varying size (Evans blue, NaCl and Sacharose). The study of the liquid filtration and flow through these supports showed that the retention rate depends on support composition and pore diameter, and solute molecular weight. The S1 support (mixture of barbotine and 1% (w/w) activated carbon) gave a flux for distilled water of 68 L/m2 h while the double-layered support resulted in a flux of 8 L/m2 h for the same solution at the pressure of 3.5 bar. At a pressure of 5.5 bar an increase in the distilled water flux through the various supports was observed. It was significant for the S1 support (230 L/m h).

  2. New Synthetic Methods and Structure-Property Relationships in Neptunium, Plutonium, and Americium Borates. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht-Schmitt, Thomas Edward

    2013-09-14

    The past three years of support by the Heavy Elements Chemistry Program have been highly productive in terms of advanced degrees awarded, currently supported graduate students, peer-reviewed publications, and presentations made at universities, national laboratories, and at international conferences. Ph.D. degrees were granted to Shuao Wang and Juan Diwu, who both went on to post-doctoral appointments at the Glenn T. Seaborg Center at Lawrence Berkeley National Laboratory with Jeff Long and Ken Raymond, respectively. Pius Adelani completed his Ph.D. with me and is now a post-doc with Peter C. Burns. Andrea Alsobrook finished her Ph.D. and is now a post-doc at Savannah River with Dave Hobbs. Anna Nelson completed her Ph.D. and is now a post-doc with Rod Ewing at the University of Michigan. As can be gleaned from this list, students supported by the Heavy Elements Chemistry grant have remained interested in actinide science after leaving my program. This follows in line with previous graduates in this program such as Richard E. Sykora, who did his post-doctoral work at Oak Ridge National Laboratory with R. G. Haire, and Amanda C. Bean, who is a staff scientist at Los Alamos National Laboratory, and Philip M. Almond and Thomas C. Shehee, who are both staff scientists at Savannah River National Laboratory, Gengbang Jin who is a staff scientist at Argonne National Lab, and Travis Bray who has been a post-doc at both LBNL and ANL. Clearly this program is serving as a pipe-line for students to enter into careers in the national laboratories. About half of my students depart the DOE complex for academia or industry. My undergraduate researchers also remain active in actinide chemistry after leaving my group. Dan Wells was a productive undergraduate of mine, and went on to pursue a Ph.D. on uranium and neptunium chalcogenides with Jim Ibers at Northwestern. After earning his Ph.D., he went directly into the nuclear industry.

  3. PDF-based heterogeneous multiscale filtration model.

    Science.gov (United States)

    Gong, Jian; Rutland, Christopher J

    2015-04-21

    Motivated by modeling of gasoline particulate filters (GPFs), a probability density function (PDF) based heterogeneous multiscale filtration (HMF) model is developed to calculate filtration efficiency of clean particulate filters. A new methodology based on statistical theory and classic filtration theory is developed in the HMF model. Based on the analysis of experimental porosimetry data, a pore size probability density function is introduced to represent heterogeneity and multiscale characteristics of the porous wall. The filtration efficiency of a filter can be calculated as the sum of the contributions of individual collectors. The resulting HMF model overcomes the limitations of classic mean filtration models which rely on tuning of the mean collector size. Sensitivity analysis shows that the HMF model recovers the classical mean model when the pore size variance is very small. The HMF model is validated by fundamental filtration experimental data from different scales of filter samples. The model shows a good agreement with experimental data at various operating conditions. The effects of the microstructure of filters on filtration efficiency as well as the most penetrating particle size are correctly predicted by the model.

  4. Stochastic control under progressive enlargement of filtrations and applications to multiple defaults risk management

    CERN Document Server

    Pham, Huyen

    2010-01-01

    We formulate and investigate a general stochastic control problem under a progressive enlargement of filtration. The global information is enlarged from a reference filtration and the knowledge of multiple random times together with associated marks when they occur. By working under a density hypothesis on the conditional joint distribution of the random times and marks, we prove a decomposition of the original stochastic control problem under the global filtration into classical stochastic control problems under the reference filtration, which are determined in a finite backward induction. Our method revisits and extends in particular stochastic control of diffusion processes with finite number of jumps. This study is motivated by optimization problems arising in default risk management, and we provide applications of our decomposition result for the indifference pricing of defaultable claims, and the optimal investment under bilateral counterparty risk. The solutions are expressed in terms of BSDEs involvin...

  5. Metal reduction at bulk chemical filtration

    Science.gov (United States)

    Umeda, Toru; Daikoku, Shusaku; Tsuzuki, Shuichi; Murakami, Tetsuya

    2017-03-01

    OK73 thinner and cyclohexanone, both of which were spiked with metals were passed through Nylon 6,6 filter, varying flow rate, which include the conditions of both point-of-use and bulk filtrations. The influent and effluent metal concentrations were measured using ICP-MS for metal removal efficiency of the filtration. As a result, removal efficiency for some metals descended depending on the flow rate, while others maintained. Slower flow rate is recommended to maintain low metal concentration in bulk filtration based on the result. Metals in cyclohexanone were reduced at higher efficiency than in OK73 thinner, agrees with a metal removal model of hydrophilic adsorbent in organic solvent, evidenced in our previous paper. Further, metal reduction on 300 mm φ Si wafer after coating organic solvents with Nylon 6,6 filtration was evidenced with TREX analysis.

  6. Filtration in coal liquefaction - Influence of filtration conditions in non-hydrogenated systems

    Science.gov (United States)

    Clarke, J. W.; Rantell, T. D.

    1980-01-01

    A series of experiments has been carried out to study the effects of filtration conditions upon the rate of filtration of non-hydrogenated coal digests. The results show the dependence of cake resistivity on both the filtration temperature and pressure. Filter cakes were found to be compressible, resulting in smaller increases in rate with increasing pressure than with incompressible cakes. The filtration temperature determines the packing of residual solids in the cake which in turn affects the cake resistivity. An empirical relation has been derived between filtration temperature and resistivity. With increasing temperature there is an increase in filtration rate due to the reduced viscosity, but a reduction owing to a higher packing density of solids in the filter cake.

  7. Complications and Management of the Filtration Bleb

    Institute of Scientific and Technical Information of China (English)

    Clement; W; N; Chan

    1992-01-01

    Filtration surgery is the commonest operation performed for closed angle or open angle glaucoma when medical treatment or laser trabeculoplasty has failed to control the intraocular pressure. It is characterized by the formation of an artificial drainage fistula between the anterior chamber and subconjunctival space. The successful operation is evidenced by the appearance of a subconjunctival filtration bleb which in turn depends on the patency of this pathway. Despite numerous modification, the procedu...

  8. Sequential injection approach for simultaneous determination of ultratrace plutonium and neptunium in urine with accelerator mass spectrometry

    DEFF Research Database (Denmark)

    Qiao, Jixin; Hou, Xiaolin; Roos, Per;

    2013-01-01

    An analytical method was developed for simultaneous determination of ultratrace level plutonium (Pu) and neptunium (Np) using iron hydroxide coprecipitation in combination with automated sequential injection extraction chromatography separation and accelerator mass spectrometry (AMS) measurement...... show that preboiling and aging are important for obtaining high chemical yields for both Pu and Np, which is possibly related to the aggregation and adsorption behavior of organic substances contained in urine. Although the optimal condition for Np and Pu simultaneous determination requires 5-day aging...... time, an immediate coprecipitation without preboiling and aging could also provide fairly satisfactory chemical yields for both Np and Pu (50-60%) with high sample throughput (4 h/sample). Within the developed method, (242)Pu was exploited as chemical yield tracer for both Pu and Np isotopes. (242)Pu...

  9. Isobaric production cross sections from 0.6 GeV proton irradiation of neptunium and thorium using mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Wenger, H.U. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)]. E-mail: hansueli.wenger@psi.ch; Al Mazouzi, A. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Atchison, F. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Burghartz, M. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Chawla, R. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); Guenther-Leopold, I. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Heimgartner, P. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Hellwig, Ch. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Ingold, F. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Kopajtic, Z. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Linder, H.P. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2006-01-09

    A high-fluence proton irradiation of neptunium was the last experiment in PSIs programme ATHENA related to accelerator-based transmutation. The principal aim of the programme has been to provide experimental data for the validation of theoretical models in nucleon-meson transport codes, with emphasis on the mass yield distribution of fission and spallation products. An improved mass spectrometry method has allowed the direct derivation of isobaric production cross sections with only minor corrections and an estimate of the fission cross section by integration in the fission hump. In a second sample position of the irradiation head, a repetition of the previous ATHENA experiment with thorium was possible, profiting from the improved mass spectrometry technique. The experimental results are better predicted by the code FUSSPOT than by HETC/RAL, both used at PSI.

  10. Properties of the filtrate from treatment of pig manure by filtration method

    Directory of Open Access Journals (Sweden)

    Makara Agnieszka

    2017-02-01

    Full Text Available This paper presents properties of filtrate obtained from pig manure using the AMAK treatment process, which includes the mineralization of macro- and microfertilizer components by the hydrolyzing of organic matter into forms that are bioavailable to plants. Filtration produced two products, sediment and filtrate. The quality of the filtrate allowed for its use as a substitute of water to irrigate crops. Concentrations of heavy metals are very low and therefore the quality of the filtrate fully complies with European standard concerning fertilizers. The used mineralization process practically eliminated odors from the filtrate. The reduction of specific odor emission by 99.1-99.5% in samples taken from above the filtrate, respectively compared to the odor concentration found in samples taken from above raw pig manure. Sediment could be used as raw material for production of mineral-organic fertilizer. Filtrate and filtration sediments analyses show that the majority of nitrogen and other fertilizing compounds included in raw pig manure remains in sediment.

  11. Multifunctional nanocomposites of carbon nanotubes and nanoparticles formed via vacuum filtration

    Science.gov (United States)

    Hersam, Mark C; Ostojic, Gordana; Liang, Yu Teng

    2013-10-22

    In one aspect, the present invention provides a method of forming a film of nanocomposites of carbon nanotubes (CNTs) and platinum (Pt) nanoparticles. In one embodiment, the method includes the steps of (a) providing a first solution that contains a plurality of CNTs, (b) providing a second solution that contains a plurality of Pt nanoparticles, (c) combining the first solution and the second solution to form a third solution, and (d) filtering the third solution through a nanoporous membrane using vacuum filtration to obtain a film of nanocomposites of CNTs and Pt nanoparticles.

  12. 21 CFR 177.2910 - Ultra-filtration membranes.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ultra-filtration membranes. 177.2910 Section 177... Components of Articles Intended for Repeated Use § 177.2910 Ultra-filtration membranes. Ultra-filtration... the processing of food, under the following prescribed conditions; (a)(1) Ultra-filtration...

  13. Efficient and reusable polyamide-56 nanofiber/nets membrane with bimodal structures for air filtration.

    Science.gov (United States)

    Liu, Bowen; Zhang, Shichao; Wang, Xueli; Yu, Jianyong; Ding, Bin

    2015-11-01

    Nanofibrous media that both possess high airborne particle interception efficiency and robust air permeability would have broad technological implications for areas ranging from individual protection and industrial security to environmental governance; however, creating such filtration media has proved extremely challenging. Here we report a strategy to construct the bio-based polyamide-56 nanofiber/nets (PA-56 NFN) membranes with bimodal structures for effective air filtration via one-step electrospinning/netting. The PA-56 membranes are composed of completely covered two-dimensional (2D) ultrathin (∼20 nm) nanonets which are optimized by facilely regulating the solution concentration, and the bonded scaffold fibers constructed cavity structures which are synchronously created by using the CH3COOH inspiration. With integrated properties of small aperture, high porosity, and bonded scaffold, the resulting PA-56 NFN membranes exhibit high filtration efficiency of 99.995%, low pressure drop of 111 Pa, combined with large dust holding capacity of 49 g/m(2) and dust-cleaning regeneration ability, for filtrating ultrafine airborne particles in the most safe manner involving sieving principle and surface filtration. The successful synthesis of PA-56 NFN medium would not only make it a promising candidate for air filtration, but also provide new insights into the design and development of nanonet-based bimodal structures for various applications.

  14. Filtration of sodium chloride from seawater using carbon hollow tube composed of carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Chaudhary Ravi Prakash Patel

    2014-07-01

    Full Text Available The present article deals with filtration of seawater to remove sodium chloride (NaCl using filter made from organized structures of carbon nanotubes (CNTs. The filter consists of hollow carbon cylinder (length ~10 cm, diameter ~1 cm, which is composed of radially aligned CNTs. This carbon hollow cylinder has been synthesized by continuous spray pyrolysis of ferrocene–benzene solution in argon atmosphere. The hollow cylinder has been turned into a water filter by closing one end and keeping a small funnel at the other. Filtration of seawater (Marina Beach, Chennai, India has been obtained both under the self pressure of seawater column in the hollow cylinder and under the difference of pressure created by enclosing the filter in a vacuum tight container. It has been found that the efficiency of filtration is about two times higher under partial vacuum (~10–2 torr created on the filtrate (water side. After filtration of seawater, a deposit in the inner surface of hollow cylinder has been found. This deposit has been characterized by X-ray diffraction, transmission electron microscopy and energy dispersive X-ray analysis, and it has been found that the deposit was NaCl. The filtration leads to almost complete removal of NaCl from the seawater.

  15. Transport of Cryptosporidium oocysts in porous media: Role of straining and physicochemical filtration

    Science.gov (United States)

    Tufenkji, N.; Miller, G.F.; Ryan, J.N.; Harvey, R.W.; Elimelech, M.

    2004-01-01

    The transport and filtration behavior of Cryptosporidium parvum oocysts in columns packed with quartz sand was systematically examined under repulsive electrostatic conditions. An increase in solution ionic strength resulted in greater oocyst deposition rates despite theoretical predictions of a significant electrostatic energy barrier to deposition. Relatively high deposition rates obtained with both oocysts and polystyrene latex particles of comparable size at low ionic strength (1 mM) suggest that a physical mechanism may play a key role in oocyst removal. Supporting experiments conducted with latex particles of varying sizes, under very low ionic strength conditions where physicochemical filtration is negligible, clearly indicated that physical straining is an important capture mechanism. The results of this study indicate that irregularity of sand grain shape (verified by SEM imaging) contributes considerably to the straining potential of the porous medium. Hence, both straining and physicochemical filtration are expected to control the removal of C. parvum oocysts in settings typical of riverbank filtration, soil infiltration, and slow sand filtration. Because classic colloid filtration theory does not account for removal by straining, these observations have important implications with respect to predictions of oocyst transport.

  16. Critical role of water content in the formation and reactivity of uranium, neptunium, and plutonium iodates under hydrothermal conditions: implications for the oxidative dissolution of spent nuclear fuel.

    Science.gov (United States)

    Bray, Travis H; Ling, Jie; Choi, Eun Sang; Brooks, James S; Beitz, James V; Sykora, Richard E; Haire, Richard G; Stanbury, David M; Albrecht-Schmitt, Thomas E

    2007-04-30

    The reactions of 237NpO2 with excess iodate under acidic hydrothermal conditions result in the isolation of the neptunium(IV), neptunium(V), and neptunium(VI) iodates, Np(IO3)4, Np(IO3)4.nH2O.nHIO3, NpO2(IO3), NpO2(IO3)2(H2O), and NpO2(IO3)2.H2O, depending on both the pH and the amount of water present in the reactions. Reactions with less water and lower pH favor reduced products. Although the initial redox processes involved in the reactions between 237NpO2 or 242PuO2 and iodate are similar, the low solubility of Pu(IO3)4 dominates product formation in plutonium iodate reactions to a much greater extent than does Np(IO3)4 in the neptunium iodate system. UO2 reacts with iodate under these conditions to yield uranium(VI) iodates solely. The isotypic structures of the actinide(IV) iodates, An(IO3)4 (An=Np, Pu), are reported and consist of one-dimensional chains of dodecahedral An(IV) cations bridged by iodate anions. The structure of Np(IO3)4.nH2O.nHIO3 is constructed from NpO9 tricapped-trigonal prisms that are bridged by iodate into a polar three-dimensional framework structure. Second-harmonic-generation measurements on a polycrystalline sample of the Th analogue of Np(IO3)4.nH2O.nHIO3 reveal a response of approximately 12x that of alpha-SiO2. Single-crystal magnetic susceptibility measurements of Np(IO3)4 show magnetically isolated Np(IV) ions.

  17. High-throughput sequential injection method for simultaneous determination of plutonium and neptunium in environmental solids using macroporous anion-exchange chromatography, followed by inductively coupled plasma mass spectrometric detection.

    Science.gov (United States)

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Miró, Manuel

    2011-01-01

    This paper reports an automated analytical method for rapid and simultaneous determination of plutonium and neptunium in soil, sediment, and seaweed, with detection via inductively coupled plasma mass spectrometry (ICP-MS). A chromatographic column packed with a macroporous anion exchanger (AG MP-1 M) was incorporated in a sequential injection (SI) system for the efficient retrieval of plutonium, along with neptunium, from matrix elements and potential interfering nuclides. The sorption and elution behavior of plutonium and neptunium onto AG MP-1 M resin was compared with a commonly utilized AG 1-gel-type anion exchanger. Experimental results reveal that the pore structure of the anion exchanger plays a pivotal role in ensuring similar separation behavior of plutonium and neptunium along the separation protocol. It is proven that plutonium-242 ((242)Pu) performs well as a tracer for monitoring the chemical yield of neptunium when using AG MP-1 M resin, whereby the difficulties in obtaining a reliable and practicable isotopic neptunium tracer are overcome. An important asset of the SI setup is the feasibility of processing up to 100 g of solid substrates using a small-sized (ca. 2 mL) column with chemical yields of neptunium and plutonium being ≥79%. Analytical results of three certified/standard reference materials and two solid samples from intercomparison exercises are in good agreement with the reference values at the 0.05 significance level. The overall on-column separation can be completed within 3.5 h for 10 g of soil samples. Most importantly, the anion-exchange mini-column suffices to be reused up to 10-fold with satisfactory chemical yields (>70%), as demanded in environmental monitoring and emergency scenarios, making the proposed automated assembly well-suited for unattended and high-throughput analysis.

  18. Asymptotics of the filtration problem for suspension in porous media

    Directory of Open Access Journals (Sweden)

    Kuzmina Ludmila Ivanovna

    2015-01-01

    Full Text Available The mechanical-geometric model of the suspension filtering in the porous media is considered. Suspended solid particles of the same size move with suspension flow through the porous media - a solid body with pores - channels of constant cross section. It is assumed that the particles pass freely through the pores of large diameter and are stuck at the inlet of pores that are smaller than the particle size. It is considered that one particle can clog only one small pore and vice versa. The particles stuck in the pores remain motionless and form a deposit. The concentrations of suspended and retained particles satisfy a quasilinear hyperbolic system of partial differential equations of the first order, obtained as a result of macro-averaging of micro-stochastic diffusion equations. Initially the porous media contains no particles and both concentrations are equal to zero; the suspension supplied to the porous media inlet has a constant concentration of suspended particles. The flow of particles moves in the porous media with a constant speed, before the wave front the concentrations of suspended and retained particles are zero. Assuming that the filtration coefficient is small we construct an asymptotic solution of the filtration problem over the concentration front. The terms of the asymptotic expansions satisfy linear partial differential equations of the first order and are determined successively in an explicit form. It is shown that in the simplest case the asymptotics found matches the known asymptotic expansion of the solution near the concentration front.

  19. HARNACK ESTIMATES FOR WEAK SOLUTIONSOFEQUATIONS OF NON-NEWTONIAN POLYTROPIC FILTRATION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An intrinsic Harnack estimate and some sup-estimates are established for nonnegative weak solutions of equations of non-Newtonian polytropic filtration ut -div(|Dum |p-2Dum) =0, m(p- 1) < 1, m>0, p> 1.

  20. Hollow fiber dead-end ultrafiltration: Influence of ionic environment on filtration of alginates

    NARCIS (Netherlands)

    Ven, van de W.J.C.; Sant, van 't K.; Punt, I.G.M.; Zwijnenburg, A.; Kemperman, A.J.B.; Meer, van der W.G.J.; Wessling, M.

    2008-01-01

    We analyze the filterability of sodium alginate solutions in different ionic environments as a function of the operational flux. The alginates serve as a model component for polysaccharides in feed water. Next to filtration characteristics, the fouling reversibility was studied by employing strictly

  1. Maize genome sequencing by methylation filtration.

    Science.gov (United States)

    Palmer, Lance E; Rabinowicz, Pablo D; O'Shaughnessy, Andrew L; Balija, Vivekanand S; Nascimento, Lidia U; Dike, Sujit; de la Bastide, Melissa; Martienssen, Robert A; McCombie, W Richard

    2003-12-19

    Gene enrichment strategies offer an alternative to sequencing large and repetitive genomes such as that of maize. We report the generation and analysis of nearly 100,000 undermethylated (or methylation filtration) maize sequences. Comparison with the rice genome reveals that methylation filtration results in a more comprehensive representation of maize genes than those that result from expressed sequence tags or transposon insertion sites sequences. About 7% of the repetitive DNA is unmethylated and thus selected in our libraries, but potentially active transposons and unmethylated organelle genomes can be identified. Reverse transcription polymerase chain reaction can be used to finish the maize transcriptome.

  2. The Perspective of Riverbank Filtration in China

    Science.gov (United States)

    Li, J.; Teng, Y.; Zhai, Y.; Zuo, R.

    2014-12-01

    Sustainable drinking water supply can affect the health of people, and the surrounding ecosystems. According to statistics of the monitoring program of drinking water sources in 309 at or above prefecture level of China in 2013, the major pollutants index were total phosphorus, ammonia and manganese in surface drinking water sources, respectively, iron, ammonia and manganese in groundwater drinking water sources, respectively. More than 150 drinking water emergency environmental accidents happened since 2006, 52 of these accidents led to the disruption of water supply in waterworks, and a population of over ten million were affected. It indicated that there is a potential risk for people's health by the use of river water directly and it is necessary to require alternative techniques such as riverbank filtration for improving the drinking water quality. Riverbank filtration is an inexpensive natural process, not only smoothing out normal pollutant concentration found in surface water but also significantly reducing the risk from such emergency events as chemical spill into the river. Riverbank filtration technique has been used in many countries more than 100 years, including China. In China, in 1950s, the bank infiltration technique was first applied in northeast of China. Extensive bank infiltration application was conducted in 1980s, and more than 300 drinking water sources utilities bank infiltration established mainly near the Songhua River Basin, the Yellow River Basin, Haihe River Basin. However, the comparative lack of application and researches on riverbank filtration have formed critical scientific data gap in China. As the performance of riverbank filtration technique depend on not only the design and setting such as well type, pumping rate, but also the local hydrogeology and environmental properties. We recommend more riverbank filtration project and studies to be conducted to collect related significant environmental geology data in China

  3. Industrial investigations of the liquid steel filtration

    Directory of Open Access Journals (Sweden)

    K. Janiszewski

    2014-07-01

    Full Text Available Hitherto existing investigations concerning the ceramic filter use in the steel making processes have given good results. The obtained results of filtration have proved that this method may be used as an effective and cheap way of steel filtration from non-metallic inclusions. Placing filters in the tundish is the best location considering the limitation of the possibility of secondary pollution of steel. Yet, the results presented in this paper, of an experiment prepared and carried out in the industrial environment, are the only positive results obtained, which are connected with so much quantities of liquid steel processed with use of the multi-hole ceramic filters.

  4. Projective Dimension in Filtrated K-Theory

    DEFF Research Database (Denmark)

    Bentmann, Rasmus Moritz

    2013-01-01

    Under mild assumptions, we characterise modules with projective resolutions of length n∈N in the target category of filtrated K-theory over a finite topological space in terms of two conditions involving certain Tor -groups. We show that the filtrated K-theory of any separable C∗dash-algebra over...... any topological space with at most four points has projective dimension 2 or less. We observe that this implies a universal coefficient theorem for rational equivariant KK-theory over these spaces. As a contrasting example, we find a separable C∗dash-algebra in the bootstrap class over a certain five...

  5. Projective Dimension in Filtrated K-Theory

    DEFF Research Database (Denmark)

    Bentmann, Rasmus Moritz

    2013-01-01

    any topological space with at most four points has projective dimension 2 or less. We observe that this implies a universal coefficient theorem for rational equivariant KK-theory over these spaces. As a contrasting example, we find a separable C∗dash-algebra in the bootstrap class over a certain five......-point space, the filtrated K-theory of which has projective dimension 3. Finally, as an application of our investigations, we exhibit Cuntz-Krieger algebras which have projective dimension 2 in filtrated K-theory over their respective primitive spectrum....

  6. CROSSFLOW FILTRATION: EM-31, WP-2.3.6

    Energy Technology Data Exchange (ETDEWEB)

    Duignan, M.; Nash, C.; Poirier, M.

    2011-02-01

    In the interest of accelerating waste treatment processing, the DOE has funded studies to better understand filtration with the goal of improving filter fluxes in existing crossflow equipment. The Savannah River National Laboratory (SRNL) performed some of those studies, with a focus on start-up techniques, filter cake development, the application of filter aids (cake forming solid precoats), and body feeds (flux enhancing polymers). This paper discusses the progress of those filter studies. Crossflow filtration is a key process step in many operating and planned waste treatment facilities to separate undissolved solids from supernate solutions. This separation technology generally has the advantage of self-cleaning through the action of wall shear stress created by the flow of waste slurry through the filter tubes. However, the ability of filter wall self-cleaning depends on the slurry being filtered. Many of the alkaline radioactive wastes are extremely challenging to filtration, e.g., those containing compounds of aluminum and iron, which have particles whose size and morphology reduce permeability. Unfortunately, low filter flux can be a bottleneck in waste processing facilities such as the Savannah River Integrated Salt Disposition Process and the Hanford Waste Treatment Plant. Any improvement to the filtration rate would lead directly to increased throughput of the entire process. To date increased rates are generally realized by either increasing the crossflow filter feed flow rate, limited by pump capacity, or by increasing filter surface area, limited by space and increasing the required pump load. SRNL set up both dead-end and crossflow filter tests to better understand filter performance based on filter media structure, flow conditions, filter cleaning, and several different types of filter aids and body feeds. Using non-radioactive simulated wastes, both chemically and physically similar to the actual radioactive wastes, the authors performed several

  7. Mechanisms of pressure filtration of liquid aluminum alloys

    Science.gov (United States)

    Cao, X.

    2006-12-01

    The Prefil Footprinter, a portable pressure filtration instrument, is usually used to detect the quality of liquid aluminum alloys. However, no investigations have ever been done to calculate the cake resistance to date. Based on the identification and classification of flow behavior using the first derivative method for filtrate mass vs filtration time curves, conventional filtration equations are successfully employed to understand the filtration behaviors. From the analyses of the variations of cake resistance with filtration time, the filtration mechanisms are discussed in detail over the different filtration stages. During the steady stage, either incompressible or compressible cake mode is the main mechanism. At the initial and terminal transient stages, however, deep-bed filtration, complete straining, and solidification clogging may appear. Solid inclusions in liquid metal have significant influence on the cake structures and properties. Some important issues related to the heterogeneity of filter media and test methodology are highlighted in this work.

  8. Intercomparison of small biomolecules by gel filtration and small angle scattering

    Energy Technology Data Exchange (ETDEWEB)

    Martel, P.; Stepanik, T.M.; Szabo, A.G. (Atomic Energy of Canada Limited, Chalk River Nuclear Laboratories, Ontario (Canada))

    1990-05-01

    This paper describes how small angle neutron scattering (SANS) can be used to confirm that gel filtration results are free of dimerization effects. After characterization by analytical gel filtration, concentrated solutions (in heavy water, D2O) of a cobra neurotoxin, a cytotoxin, and a cytotoxin analog are studied by SANS. Small differences in shape are shown to be discernible by means of least-square fits to ellipsoidal models. The parallel axis theorem is then invoked to assess dimerization levels statistically. The results are briefly discussed on the basis of function in relation to structure.

  9. Isolation of americium (5) oxalate compounds from solutions

    Energy Technology Data Exchange (ETDEWEB)

    Zubarev, V.G.; Krot, N.N.

    1982-01-01

    Certain conditions of americium (5) isolation with solutions of ammonia and KOH are studied as well as the attitude of hydroxide obtained to heating. Like neptunium (5) hydroxide americium (5) hydroxide probably has the formula AmO/sub 2/OHxxH/sub 2/O, where x is approximately equal to 2.3. It is established that during heating in the air up to 120 deg C hydroxide transforms into AmO/sub 2/. It is shown that in solutions with a high concentration of oxalate-ion americium stability in oxidation state +5 depends greatly on the pH of solution. Complex salts KAmO/sub 2/C/sub 2/O/sub 4/xxH/sub 2/O and CsAmO/sub 2/C/sub 2/O/sub 4/xxH/sub 2/O are synthesized. The identification is made according to the method of preparation and results of analysis of C/sub 2/O/sub 4//sup 2 -/: AmO/sub 2//sup +/ ratio. It is found that the salts are non-isomorphous to similar salts of pentavalent neptunium. CsAmO/sub 2/C/sub 2/O/sub 4/xxH/sub 2/O is identified in cubic crystal system with the lattice constant a=1.25 nm.

  10. Aerosol filtration - performance of filter media; Filtration des aerosols - performances des medias filtrants

    Energy Technology Data Exchange (ETDEWEB)

    Bemer, D.; Regnier, R. [Institut National de Recherche et de Securite (INRS), Dept. Ingenierie des Procedes, 75 - Paris (France); Calle, S.; Thomas, D.; Simon, X.; Appert-Collin, J.Ch. [Centre National de la Recherche Scientifique (CNRS), Lab. des Sciences du Genie Chimique de Nancy, 54 - Vandoeuvre-les-Nancy (France)

    2006-03-15

    Set up in 2000, the Laboratoire de Filtration des Aerosols in Nancy (LFA), associating research teams from INRS (Institut National de Recherche et de Securite and LSGC (Laboratoire des Sciences du Genie Chimique - CNRS), has been commissioned to provide expertise in the aerosol filtration field to both CRAM (Caisse Regionale de l'Assurance Maladie) prevention specialists and industrialists. Following a theoretical review of fibre medium filtration, this paper summarises the different actions undertaken by the LFA: filter performance during clogging with liquid and solid aerosols, modelling, pneumatic unclogging of baghouse dust collectors, influence of micro-leaks, etc. (authors)

  11. BLOW-UP ESTIMATES FOR A NON-NEWTONIAN FILTRATION SYSTEM

    Institute of Scientific and Technical Information of China (English)

    杨作东; 陆启韶

    2001-01-01

    The prior estimate and decay property of positive solutions are derived for a system of quasi-linear elliptic differential equations first. Hence, the result of non-existence for differential equation system of radially nonincreasing positive solutions is implied. By using this non-existence result, blow-up estimates for a class quasi-linear reaction-diffusion systems (non-Newtonian filtration systems ) are established, which extends the result of semi- linear reaction- diffusion ( Fujita type ) systems .

  12. Prevention of febrile nonhemolytic transfusion reaction with leucocyte filtrated concentrates

    Institute of Scientific and Technical Information of China (English)

    ZHAO Shu-ming; XIANG Guo-chun; ZHANG Jia-si; CHENG Xiao-ling; LI Ru-qing

    2002-01-01

    Objective: To assess the clinical efficiency of the transfusion of leucocyte filtrated RBC concentrates to prevent febrile nonhemolytic transfusion reactions (FNHTRs). Methods: One hundred patients with liver cirrhosis, gastric ulcer or cancer were subjected to receive RBC concentrates after leucocyte filtration.Another 50 patients with similar diseases were selected to receive non-filtrated RBC concentrates. The incidence of FNHTRs in all patients was investigated. Results: There was no FNHTR in 100 transfusions with leucocyte filtrated RBC concentrates, while FNHTRs occurred in 8 of 50 patients with non-filtrated RBC concentrates, with the incidence of 160%. Conclusion: FNHTRs to RBC transfusion can be prevented with leucocyte filtration.

  13. Plasma discharge self-cleaning filtration system

    Science.gov (United States)

    Cho, Young I.; Fridman, Alexander; Gutsol, Alexander F.; Yang, Yong

    2014-07-22

    The present invention is directed to a novel method for cleaning a filter surface using a plasma discharge self-cleaning filtration system. The method involves utilizing plasma discharges to induce short electric pulses of nanoseconds duration at high voltages. These electrical pulses generate strong Shockwaves that disintegrate and dislodge particulate matter located on the surface of the filter.

  14. Organic micropollutant removal during river bank filtration

    NARCIS (Netherlands)

    Bertelkamp, C.

    2015-01-01

    This study investigated the factors influencing the main removal mechanisms (adsorption and biodegradation) for organic micropollutant (OMP) removal during river bank filtration (RBF) and the possibility of developing a predictive model of this process for OMP removal during RBF. Chapter 2 analysed

  15. [Clinical experience of automated double filtration plasmapheresis].

    Science.gov (United States)

    Lee, C T; Chuang, F R; Hsu, K T; Lam, K K; Liao, S C; Liu, C C; Chen, J B; Jang, S W; Chien, Y S; Pan, H H

    1996-12-01

    Double filtration plasmapheresis, one kind of fractionation plasmapheresis, was developed from membrane type plasmapheresis to remove only the pathogen and return the normal protein back to the patient. We started our automated double filtration plasmapheresis since December 1993. There were 13 patients who received one hundred treatments totally during one year period. And they are myasthenia gravis (8 patients); acute inflammatory demyelinating polyneuropathy (1 patient), multiple myeloma (1 patient); acquired factor VIII inhibitor (1 patient); autoimmune hemolytic anemia (1 patient); systemic lupus erythematous (1 patient). Technically double filtration plasmapheresis is easy to perform and time-saving. It also makes necessity of replacement fluid less frequent. Incidence of complication is rare, and this includes hypotension 2%, palpitation 1%, headache 1%, hemolysis 4%, air emboli 1%, high secondary pressure 2%, and no motality during our treatment. Clinical response is documented in cases of myasthenia gravis; acute inflammatory demyelinating polyneuropathy and acquired factor VIII inhibitor in our study. In conclusion, double filtration plasmapheresis is a time-saving, convenient, and safe therapeutic modality with rare complication. Because its effectiveness on limited kinds of diseases and costs relatively high price, thus plasmapheresis should be used in selected cases and treat aggressively if indicated.

  16. Advances in hot gas filtration technology

    Energy Technology Data Exchange (ETDEWEB)

    Weber, C.

    The past decade has seen the introduction of new filter media specifically designed for 'hot-gas' filtration. These media are available as woven or knitted fabrics and as non-wovens, i.e. needled felts. Needlefelted fabrics have proven so highly successful in the dedusting of hot gases that they are widely used nowadays in this new and necessary technology. Hot-gas filtration offers advantages in, for example, the saving or recycling of energy, the elimination of the cooling process, and the short-circuiting of process steps. This paper gives a survey of the types of textile fibres available for hot-gas filtration from the more recently developed organic fibres to refractory fibres. It describes, compares and contrasts their salient properties and lists the uses to which they may be put. It concentrates on such fibres which are generally referred to as 'high performance materials', since they are expected to provide satisfactory performance under extreme conditions of temperature, chemical environment and mechanical stress. It touches on filtration theory governing the collection mechanism. 9 refs., 7 figs., 3 tabs.

  17. Using Digital Filtration for Hurst Parameter Estimation

    Directory of Open Access Journals (Sweden)

    J. Prochaska

    2009-06-01

    Full Text Available We present a new method to estimate the Hurst parameter. The method exploits the form of the autocorrelation function for second-order self-similar processes and is based on one-pass digital filtration. We compare the performance and properties of the new method with that of the most common methods.

  18. A simple filtration technique for obtaining purified human chromosomes in suspension.

    Science.gov (United States)

    Yusuf, Mohammed; Parmar, Neha; Bhella, Gurdeep K; Robinson, Ian K

    2014-05-01

    Here we present a simple method for cleaning polyamine human mitotic chromosomes in solution. This was achieved by filtering intact (unburst) nuclei along with both large and small cytoplasmic debris through a series of different pore sized filters. Pure human chromosomes were recovered using a simple reverse filtration step. Fluorescence microscopy was used to validate the chromosome suspension after each filtration step. This reverse filtration technique is an improvement in both procedure time and chromosome recovery compared to currently used post-purification methods. Chromosomes purified by our method could be used for many applications, such as structural studies using microfluidics and high resolution imaging or generation of chromosome paints and sequencing after flow cytometry.

  19. Dynamic fouling behaviors of submerged nonwoven bioreactor for filtration of activated sludge with different SRT.

    Science.gov (United States)

    Chuang, Shun-Hsing; Lin, Po-Kuen; Chang, Wei-Chin

    2011-09-01

    The flux variations and resistances accumulated during filtration of activated sludge with sludge retention time (SRT) of 15, 30, and 60 days were analyzed to investigate the dynamic fouling behavior in a submerged nonwoven bioreactor. Different SRT values varied sludge condition and particle size distribution in the supernatants, which caused dissimilar fouling characteristics. Short-term fouling of the nonwoven bioreactor during filtration of activated sludge with SRT of 15 days was fully reversible, and the resistance percentages of solutes, colloids, and suspended solids were 6%, 27%, and 67%, respectively. On the other hand, significant increases of colloid resistance, such as with the filtration of activated sludge with SRT of 30 and 60 days, were related to the occurrence of irreversible fouling. The phenomenon of pore blocking by particles or colloids with size analogous to the pore of nonwoven fabric was a decisive factor leading to irreversible fouling in the large-pore materials.

  20. Carbon Nanotube Membranes: Synthesis, Properties, and Future Filtration Applications

    Directory of Open Access Journals (Sweden)

    Md. Harun-Or Rashid

    2017-05-01

    Full Text Available Over the course of the past decade, there has been growing interest in the development of different types of membranes composed of carbon nanotubes (CNTs, including buckypapers and composite materials, for an ever-widening range of filtration applications. This article provides an overview of how different types of CNT membranes are prepared and the results obtained from investigations into their suitability for different applications. The latter involve the removal of small particles from air samples, the filtration of aqueous solutions containing organic compounds and/or bacteria, and the separation of individual liquids present in mixtures. A growing number of reports have demonstrated that the incorporation of CNTs into composite membranes confers an improved resistance to fouling caused by biomacromolecules and bacteria. These results are discussed, along with evidence that demonstrates it is possible to further reduce fouling by taking advantage of the inherent conductivity of composite membranes containing CNTs, as well as by using different types of electrochemical stimuli.

  1. Optimization of biomolecule separation by combining microscale filtration and design-of-experiment methods.

    Science.gov (United States)

    Kazemi, Amir S; Kawka, Karina; Latulippe, David R

    2016-10-01

    There is considerable interest in developing microscale (i.e., high-throughput) methods that enable multiple filtration experiments to be run in parallel with smaller sample amounts and thus reduce the overall required time and associated cost to run the filtration tests. Previous studies to date have focused on simply evaluating the filtration capacity, not the separation performance. In this work, the stirred-well filtration (SWF) method was used in combination with design-of-experiment (DOE) methods to optimize the separation performance for three binary mixtures of bio-molecules: protein-protein, protein-polysaccharide, and protein-DNA. Using the parallel based format of the SWF method, eight constant-flux ultrafiltration experiments were conducted at once to study the effects of stirring conditions, permeate flux, and/or solution conditions (pH, ionic strength). Four separate filtration tests were conducted for each combination of process variables; in total, over 100 separate tests were conducted. The sieving coefficient and selectivity results are presented to match the DOE design format and enable a greater understanding of the effects of the different process variables that were studied. The method described herein can be used to rapidly determine the optimal combination of process factors that give the best separation performance for a range of membrane-based separations applications and thus obviate the need to run a large number of traditional lab-scale tests. Biotechnol. Bioeng. 2016;113: 2131-2139. © 2016 Wiley Periodicals, Inc.

  2. Membrane fouling and dialysate flow pattern in an internal filtration-enhancing dialyzer.

    Science.gov (United States)

    Yamamoto, Ken-ichiro; Hiwatari, Michihito; Kohori, Fukashi; Sakai, Kiyotaka; Fukuda, Makoto; Hiyoshi, Tatsuo

    2005-01-01

    For efficient removal of large molecular weight solutes by dialysis, several types of internal filtration-enhancing dialyzers (IFEDs) are commercially available. However, in a pressure-driven membrane separation process (i.e., filtration), membrane fouling caused by adhesion of plasma proteins is a severe problem. The objective of the present study is to investigate the effects of internal filtration on membrane fouling based on the membrane's pure-water permeability, diffusive permeability, and sieving coefficient. Hemodialysis experiments were performed with two different dialyzers, IFEDs and non-IFEDs. Local membrane fouling in each dialyzer was evaluated by measuring the pure-water permeability, the diffusive permeability, and the sieving coefficient of native membranes and membranes treated with bovine blood. The effects of packing ratio on dialysate flow pattern were also evaluated by measuring the time required for an ion tracer to reach electrodes placed in the dialyzers. In the IFED, membrane fouling caused by protein adhesion is increased because of enhanced internal filtration only at the early stage of dialysis, and this fouling tends to occur only near the dialysate outlet port. However, enhanced internal filtration has little effect on measured membrane transfer parameters.

  3. Adsorptive removal of nitrilotris(methylenephosphonic acid) antiscalant from membrane concentrates by iron-coated waste filtration sand.

    Science.gov (United States)

    Boels, L; Tervahauta, T; Witkamp, G J

    2010-10-15

    Iron-coated waste filtration sand was investigated as a low-cost adsorbent for the removal of nitrilotris(methylenephosphonic acid) (NTMP) from membrane concentrates. The adsorption of this phosphonate-based antiscalant on this material was measured and compared with two commercially available anion exchange resins and activated carbon. Comprehensive adsorption experiments were conducted in several synthetic concentrate solutions and in a concentrate collected from a full scale nano-filtration brackish water desalination plant. The effect of pH, ionic strength and the presence of competitive anions on the equilibrium adsorption were investigated. The results showed that, in contrast to the anion exchange resins, the adsorption on coated filtration sand is not suppressed at increasing ionic strength and is much less affected by the competitive anions carbonate and sulphate. The adsorption decreased slightly when the pH was raised from 7.0 to 8.0. The adsorption isotherms in the real nano-filtration concentrate, measured in the concentration interval of 5-50 mg dm(-1) NTMP, showed that the maximum adsorption capacity of coated filtration sand was 4.06 mg g(-1). The adsorption capacity per unit mass of the adsorbents at low NTMP concentration (12.5 mg dm(-3)) followed the decreasing order Amberlite IRA-410>coated filtration sand>Amberlite IRA-900>Norit SAE Super. This demonstrates that the use of iron-coated waste filtration sand offers a promising means for the removal of NTMP from membrane concentrates.

  4. OPTIMIZATION OF THE PROCESS OF DRYING THE FILTRATE DISTILLERY DREGS

    Directory of Open Access Journals (Sweden)

    A. A. Shevtsov

    2013-01-01

    Full Text Available The interactions of various factors affecting the process of drying the filtrate distillery dregs are investigated. Rational conditions for the process of drying the filtrate distillery dregs in a spray dryer are obtained.

  5. Technology Review of Modern Gas Turbine Inlet Filtration Systems

    OpenAIRE

    2012-01-01

    An inlet air filtration system is essential for the successful operation of a gas turbine. The filtration system protects the gas turbine from harmful debris in the ambient air, which can lead to issues such as FOD, erosion, fouling, and corrosion. These issues if not addressed will result in a shorter operational life and reduced performance of the gas turbine. Modern day filtration systems are comprised of multiple filtration stages. Each stage is selected based on the local operating envir...

  6. Derivation of the formula for the filtration coefficient by application of Poiseuille's law in membrane transport

    Directory of Open Access Journals (Sweden)

    Maria Jarzyńska

    2011-01-01

    Full Text Available On the basis of Kedem-Katchalsky equations a mathematical analysis of volume flow (Jv of a binary solution through a membrane (M is presented. Two cases of transport generators have been considered: hydrostatic (Δp as well as osmotic (Δπ pressure difference. Based on the Poiseuille's law we derive the formula for the membrane filtration coefficient (Lp which takes into account the membrane properties, kinetic viscosity and density of a solution flowing across the membrane. With use of this formula we have made model calculations of the filtration coefficient Lp and volume flow Jv for a polymer membrane in the case when the solutions on both sides of the membrane are mixed.

  7. Hydrophilicity improvement in polyphenylsulfone nanofibrous filtration membranes through addition of polyethylene glycol

    Science.gov (United States)

    Kiani, Shirin; Mousavi, Seyed Mahmoud; Shahtahmassebi, Nasser; Saljoughi, Ehsan

    2015-12-01

    Novel hydrophilic polyphenylsulfone (PPSU) nanofibrous membrane was prepared by electrospinning of the PPSU solution blended with polyethylene glycol 400 (PEG 400). The influence of the PEG concentration on the membrane characteristics was studied using scanning electron microscopy (SEM), water contact angle measurement, and tensile test. Filtration performance of the membranes was investigated by measurement of pure water flux (PWF) and determination of the rejection values of the pollution indices during treatment of canned beans production wastewater. According to the results, blending the PPSU solution with 10 wt.% PEG 400 resulted in formation of a nanofibrous membrane with high porosity and increased mechanical strength which exhibited a low water contact angle of 8.9° and high water flux of 7920 L/m2h. Flux recovery of the mentioned membrane which was assessed by filtration of a solution containing bovine serum albumin (BSA) was 83% indicating a noticeable antifouling property.

  8. Cake filtration modeling: Analytical cake filtration model and filter medium characterization

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Michael

    2008-05-15

    Cake filtration is a unit operation to separate solids from fluids in industrial processes. The build up of a filter cake is usually accompanied with a decrease in overall permeability over the filter leading to an increased pressure drop over the filter. For an incompressible filter cake that builds up on a homogeneous filter cloth, a linear pressure drop profile over time is expected for a constant fluid volume flow. However, experiments show curved pressure drop profiles, which are also attributed to inhomogeneities of the filter (filter medium and/or residual filter cake). In this work, a mathematical filter model is developed to describe the relationship between time and overall permeability. The model considers a filter with an inhomogeneous permeability and accounts for fluid mechanics by a one-dimensional formulation of Darcy's law and for the cake build up by solid continuity. The model can be solved analytically in the time domain. The analytic solution allows for the unambiguous inversion of the model to determine the inhomogeneous permeability from the time resolved overall permeability, e.g. pressure drop measurements. An error estimation of the method is provided by rewriting the model as convolution transformation. This method is applied to simulated and experimental pressure drop data of gas filters with textile filter cloths and various situations with non-uniform flow situations in practical problems are explored. A routine is developed to generate characteristic filter cycles from semi-continuous filter plant operation. The model is modified to investigate the impact of non-uniform dust concentrations. (author). 34 refs., 40 figs., 1 tab

  9. 40 CFR 141.171 - Criteria for avoiding filtration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Criteria for avoiding filtration. 141... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving 10,000 or More People § 141.171 Criteria for avoiding filtration. In addition to...

  10. 40 CFR 141.174 - Filtration sampling requirements.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Filtration sampling requirements. 141... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving 10,000 or More People § 141.174 Filtration sampling requirements. (a)...

  11. 40 CFR 141.71 - Criteria for avoiding filtration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Criteria for avoiding filtration. 141... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.71 Criteria for avoiding filtration. A public water system that uses a surface water source must meet all...

  12. Origins of the poor filtration characteristics of wheat starch hydrolysates

    NARCIS (Netherlands)

    Matser, A.M.; Steeneken, P.A.M.

    1998-01-01

    The effects of wheat starch components on the filtration characteristics of wheat starch hydrolysates were investigated with a model-based approach. The filtration rate was not affected by the removal of the pentosans or by altering the conformation of the protein. On the other hand, the filtration

  13. Nanoparticles filtration by leaked fibrous filters

    Energy Technology Data Exchange (ETDEWEB)

    Mouret, Guillaume; Calle-Chazelet, Sandrine; Thomas, Dominique; Appert-Collin, Jean-Christophe [Nancy-Universite/LSGC/CNRS - 1 rue Grandville - BP 20451 - F-54001 Nancy Cedex (France)], E-mail: sandrine.calle@ensic.inpl-nancy.fr; Bemer, Denis [INRS - Avenue de Bourgogne - F-54501 Vandoeuvre les Nancy Cedex (France)

    2009-05-01

    The aim of this work is first to measured nanoparticles penetration through three different fiberglass filters intentionally-pierced with calibrated needles at different filtration velocity. Then a semi-empirical model based on the air flow resistances of the new and perforated filter media and on the mechanism of Brownian diffusion for the collection of ultrafine particles by the media enables to well predict the efficiency observed for all tested operating conditions. Results show that the increase of particles penetration is all the more important that the pinhole is large and that the particle diameter is low. Another result is that the filtration efficiency of the new filter media controlled the penetration. A high efficiency filter with a high resistance to air flow will be more damaged than a low efficiency filter when being perforated.

  14. Integrative filtration research and sustainable nanotechnology

    Institute of Scientific and Technical Information of China (English)

    Jing Wang; Drew Thompson; David Y.H.Pui

    2013-01-01

    With the wide applications of nanomaterials in an array of industries,more concerns are being raised about the occupational health and safety of nanoparticles in the workplace,and implications of nanotechnology on the environment and living systems.Studies on environmental,health and safety (EHS) issues of nanomaterials play a significant role in public acceptance,and eventual sustainability,of nanotechnology.We present research results on three aspects of the EHS studies:characterization and measurement of nanoparticles,nanoparticle emission and exposure at workplaces,and control and abatement of nanoparticle release using filtration technology.Measurement of nanoparticle agglomerates using a newly developed instrument,the Universal Nanoparticle Analyzer,is discussed.Nanoparticle emission and exposure measurement results for carbon nanotubes in the manufacture of nanocomposites and for silicon nanoparticles in their production at a pilot scale facility are presented.Filtration of nanoparticles and nanoparticle agglomerates are also studied.

  15. Air filtration and indoor air quality

    DEFF Research Database (Denmark)

    Bekö, Gabriel

    2006-01-01

    Demands for better indoor air quality are increasing, since we spend most of our time indoors and we are more and more aware of indoor air pollution. Field studies in different parts of the world have documented that high percentage of occupants in many offices and buildings find the indoor air...... decent ventilation and air cleaning/air filtration, high indoor air quality cannot be accomplished. The need for effective air filtration has increased with increasing evidence on the hazardous effects of fine particles. Moreover, the air contains gaseous pollutants, removal of which requires various air...... cleaning techniques. Supply air filter is one of the key components in the ventilation system. Studies have shown that used ventilation filters themselves can be a significant source of indoor air pollution with consequent impact on perceived air quality, sick building syndrome symptoms and performance...

  16. Breakthrough of cyanobacteria in bank filtration.

    Science.gov (United States)

    Pazouki, Pirooz; Prévost, Michèle; McQuaid, Natasha; Barbeau, Benoit; de Boutray, Marie-Laure; Zamyadi, Arash; Dorner, Sarah

    2016-10-01

    The removal of cyanobacteria cells in well water following bank filtration was investigated from a source water consisting of two artificial lakes (A and B). Phycocyanin probes used to monitor cyanobacteria in the source and in filtered well water showed an increase of fluorescence values demonstrating a progressive seasonal growth of cyanobacteria in the source water that were correlated with cyanobacterial biovolumes from taxonomic counts (r = 0.59, p cyanobacteria. Of cyanobacteria that passed through bank filtration, smaller cells were significantly more frequent in well water samples (p cyanobacteria to wells. Winter samples demonstrated that cyanobacteria accumulate within bank filters, leading to continued passage of cells beyond the bloom season. Although no concentrations of total microcystin-LR were above detection limits in filtered well water, there is concern that cyanobacterial cells that reach the wells have the potential to contain intracellular toxins. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. The filtration properties of a dimorphic yeast

    OpenAIRE

    McCarthy, Anthony A

    2001-01-01

    A dimorphic yeast Kluyveromyces marxianu var. marxianus NRRLy2415 which exhibits a wide range of mean morphological forms was used as a model organism to investigate the role of cell morphology on the dead-end and crossflow filtration behaviour. Varying the culturing conditions produced cell suspensions of different mean morphology. Batch fermentations were used to produce yeast-like morphologies and continuous cultures produced cells more mycelial in nature. Semi-automated image analysis was...

  18. Symptomatic hyponatremia during glomerular filtration rate testing

    OpenAIRE

    2010-01-01

    Hyponatremia affects nearly one in five of all hospitalized patients. Severe hyponatremia is associated with significant morbidity and mortality, and is therefore important to recognize. Prior reports have linked duloxetine with hyponatremia, but it is uncommon. In this case report, we describe a research subject taking duloxetine who developed severe symptomatic hyponatremia during glomerular filtration rate testing despite having undergone such testing uneventfully in the past.

  19. Flux Enhancement in Crossflow Membrane Filtration: Fouling and It's Minimization by Flow Reversal

    Energy Technology Data Exchange (ETDEWEB)

    Shamsuddin Ilias

    2005-08-04

    Fouling problems are perhaps the single most important reason for relatively slow acceptance of ultrafiltration in many areas of chemical and biological processing. To overcome the losses in permeate flux associated with concentration polarization and fouling in cross flow membrane filtration, we investigated the concept of flow reversal as a method to enhance membrane flux in ultrafiltration. Conceptually, flow reversal prevents the formation of stable hydrodynamic and concentration boundary layers at or near the membrane surface. Further more, periodic reversal of the flow direction of the feed stream at the membrane surface results in prevention and mitigation of membrane fouling. Consequently, these advantages are expected to enhance membrane flux significantly. A crossflow membrane filtration unit was designed and built to test the concept of periodic flow reversal for flux enhancement. The essential elements of the system include a crossflow hollow fiber membrane module integrated with a two-way valve to direct the feed flow directions. The two-way valve is controlled by a controller-timer for periodic reversal of flow of feed stream. Another important feature of the system is that with changing feed flow direction, the permeate flow direction is also changed to maintain countercurrent feed and permeate flows for enhanced mass transfer driving force (concentration difference). Three feed solutions (Bovine serum albumin (BSA), apple juice and citrus fruit pectin) were studied in crossflow membrane filtration. These solutes are well-known in membrane filtration for their fouling and concentration polarization potentials. Laboratory-scale tests on a hollow-fiber ultrafiltration membrane module using each of the feed solutes show that under flow reversal conditions, the permeate flux is significantly enhanced when compared with the conventional unidirectional flow. The flux enhancement is dramatic (by an order of magnitude) with increased feed concentration and

  20. Portable Hybrid Powered Water Filtration Device

    Directory of Open Access Journals (Sweden)

    Maria Lourdes V. Balansay

    2015-08-01

    Full Text Available The existing water filtration device has features that can be developed to be more useful and functional during emergency situations. The project’s development has been aided by following provisions in PEC, NEC, NEMA and Philippine National Standard for Safe Drinking Water provide standards for the construction of the project. These standards protect both the prototype and the user. These also served as guide for the maintenance of every component. The design of the portable hybrid powered water filtration device shows that the project has more advanced features such as portability and the power supply used such as photovoltaic module solar cells and manually operated generator. This also shows its effectiveness and reliability based on the results of discharging test, water quality test and water production test. Based on analysis of the overall financial aspects, the machine can be profitable and the amount of revenue and operating cost will increase as years pass. Using the proper machine/ tools and methods of fabrication helps in easy assembly of the project. The materials and components used are cost effective and efficient. The best time for charging the battery using solar panel is 9:00 am onwards while the hand crank generator is too slow because the generated current is little. The water filtration device is very efficient regarding the operating hours and water production. The machine may have a great effect to society and economy in generation of clean available water at less cost.

  1. Stuies of neptunium(V) sorption on montmorillonite, clinoptilolite, quartz and {alpha}-alumina

    Energy Technology Data Exchange (ETDEWEB)

    Bertetti, F.P.; Pabalan, R.T.; Turner, D.R.; Almendarez, M.G. [Southwest Research Institute, San Antonio, TX (United States)

    1996-10-01

    {sup 237}Np is a particular concern to the safety suitability of Yucca Mountain, Nevada, as a geologic repository for high-level nuclear wastes. In this study, montmorillonite, clinoptilolite, quartz, and {alpha}-alumina were reacted with {sup 237}Np-bearing solutions to characterize the sorption behavior of Np(V) on these minerals. Batch experiments were conducted at room temperature (20{plus_minus}2{degrees}C) over a range of conditions in which solution pH, sorbent surface area, initial concentration of N(V), ionic strength, and partial pressure of CO{sub 2} were varied. For all the minerals studied, Np(V) sorption begins at pH values coincident with the start of Np hydrolysis in solution ({approximately}6.5-7). For solutions undersaturated with respect to atmospheric CO{sub 2}, sorption increases continuously with increasing pH. For solutions at equilibrium with atmospheric CO{sub 2}, the {open_quotes}sorption envelope{close_quotes} is coincident with the calculated predominance field (pH {approximately}7-9.5) of the NpO{sub 2}(OH){sup 0}(aq) species, and sorption is inhibited at higher pH where neptunyl carbonate complexes predominate. Modeling of the sorption behavior of Np(V) was performed using a surface complexation-approach (Diffuse-Layer Model).

  2. Aerosol Filtration Application Using Fibrous Media An Industrial Perspective

    Institute of Scientific and Technical Information of China (English)

    杨传芳

    2012-01-01

    Filtration of aerosol particles using non-woven fibrous media is a common practice for air cleaning. It has found wide applications in industries and our daily lives. This paper overviews some of these applications and provides an industrial perspective. It starts from discussing aerosol filtration theory, followed by a brief review on the advancement of filtration media. After that, filtration applications in respiratory protection, dust collection, and engine in-take air cleaning are elaborated. These are the areas that the author sees as the typical needed ones in China's fast pace economical development endeavor, where air filtration enables the protection of human health, environment and equipment for sustainability.

  3. Filtration Combustion in Smoldering and SHS

    Science.gov (United States)

    Matkowsky, Bernard J.

    2001-01-01

    Smolder waves and SHS (self-propagating high-temperature synthesis) waves are both examples of filtration combustion waves propagating in porous media. Smoldering combustion is important for the study of fire safety. Smoldering itself can cause damage, its products are toxic and it can also lead to the more dangerous gas phase combustion which corresponds to faster propagation at higher temperatures. In SHS , a porous solid sample, consisting of a finely ground powder mixture of reactants, is ignited at one end. A high temperature thermal wave, having a frontal structure, then propagates through the sample converting reactants to products. The SHS technology appears to enjoy a number of advantages over the conventional technology, in which the sample is placed in a furnace and "baked" until it is "well done". The advantages include shorter synthesis times, greater economy, in that the internal energy of the reactions is employed rather than the costly external energy of the furnace, purer products, simpler equipment and no intrinsic limitation on the size of the sample to be synthesized as exists in the conventional technology. When delivery of reactants through the pores to the reaction site is an important aspect of the combustion process, it is referred to as filtration combustion. The two types of filtration combustion have a similar mathematical formulation, describing the ignition, propagation and extinction of combustion waves in porous media. The goal in each case, however, is different. In smoldering the desired goal is to prevent propagation, whereas in SHS the goal is to ensure propagation of the combustion wave, leading to the synthesis of desired products. In addition, the scales in the two areas of application differ. Smoldering generally occurs at lower temperatures and propagation velocities than in SHS nevertheless, the two applications have much in common so that what is learned fit make application can be used to advantage in the other. In porous

  4. Nanofiber filter media for air filtration

    Science.gov (United States)

    Raghavan, Bharath Kumar

    Nanofibers have higher capture efficiencies in comparison to microfibers in the submicron particle size range of 100-500 nm because of small fiber diameter and increased surface area of the fibers. Pressure drop across the filter increases tremendously with decrease in fiber diameter in the continuum flow regime. Nanofibers with fiber diameter less than 300 nm are in the slip flow regime as a consequence of which steep increase in pressure drop is considerably reduced due to slip effect. The outlet or inlet gases have broad range of particle size distribution varying from few micrometers to nanometers. The economic benefits include capture of a wide range of particle sizes in the gas streams using compact filters composed of nanofibers and microfibers. Electrospinning technique was used to successfully fabricate polymeric and ceramic nanofibers. The nanofibers were long, continuous, and flexible with diameters in the range of 200--300 nm. Nanofibers were added to the filter medium either by mixing microfibers and nanofibers or by directly electrospinning nanofibers as thin layer on the surface of the microfiber filter medium. Experimental results showed that either by mixing Nylon 6 nanofibers with B glass fibers or by electrospinning Nylon 6 nanofibers as a thin layer on the surface of the microfiber medium in the surface area ratio of 1 which is 0.06 g of nanofibers for 2 g of microfibers performed better than microfiber filter media in air filtration tests. This improved performance is consistent with numerical modeling. The particle loading on a microfibrous filter were studied for air filtration tests. The experimental and modeling results showed that both pressure drop and capture efficiency increased with loading time. Nanofiber filter media has potential applications in many filtration applications and one of them being hot gas filtration. Ceramic nanofibers made of alumina and titania nanofibers can withstand in the range of 1000°C. Ceramic nanofibers

  5. Filtration Efficiency of Functionalized Ceramic Foam Filters for Aluminum Melt Filtration

    Science.gov (United States)

    Voigt, Claudia; Jäckel, Eva; Taina, Fabio; Zienert, Tilo; Salomon, Anton; Wolf, Gotthard; Aneziris, Christos G.; Le Brun, Pierre

    2017-02-01

    The influence of filter surface chemistry on the filtration efficiency of cast aluminum alloys was evaluated for four different filter coating compositions (Al2O3—alumina, MgAl2O4—spinel, 3Al2O3·2SiO2—mullite, and TiO2—rutile). The tests were conducted on a laboratory scale with a filtration pilot plant, which facilitates long-term filtration tests (40 to 76 minutes). This test set-up allows the simultaneous use of two LiMCAs (before and after the filter) for the determination of the efficiency of inclusion removal. The four tested filter surface chemistries exhibited good thermal stability and mechanical robustness after 750 kg of molten aluminum had been cast. All four filter types exhibited a mean filtration efficiency of at least 80 pct. However, differences were also observed. The highest filtration efficiencies were obtained with alumina- and spinel-coated filter surfaces (>90 pct), and the complete removal of the largest inclusions (>90 µm) was observed. The efficiency was slightly lower with mullite- and rutile-coated filter surfaces, in particular for large inclusions. These observations are discussed in relation to the properties of the filters, in particular in terms of, for example, the surface roughness.

  6. Filtration Efficiency of Functionalized Ceramic Foam Filters for Aluminum Melt Filtration

    Science.gov (United States)

    Voigt, Claudia; Jäckel, Eva; Taina, Fabio; Zienert, Tilo; Salomon, Anton; Wolf, Gotthard; Aneziris, Christos G.; Le Brun, Pierre

    2016-12-01

    The influence of filter surface chemistry on the filtration efficiency of cast aluminum alloys was evaluated for four different filter coating compositions (Al2O3—alumina, MgAl2O4—spinel, 3Al2O3·2SiO2—mullite, and TiO2—rutile). The tests were conducted on a laboratory scale with a filtration pilot plant, which facilitates long-term filtration tests (40 to 76 minutes). This test set-up allows the simultaneous use of two LiMCAs (before and after the filter) for the determination of the efficiency of inclusion removal. The four tested filter surface chemistries exhibited good thermal stability and mechanical robustness after 750 kg of molten aluminum had been cast. All four filter types exhibited a mean filtration efficiency of at least 80 pct. However, differences were also observed. The highest filtration efficiencies were obtained with alumina- and spinel-coated filter surfaces (>90 pct), and the complete removal of the largest inclusions (>90 µm) was observed. The efficiency was slightly lower with mullite- and rutile-coated filter surfaces, in particular for large inclusions. These observations are discussed in relation to the properties of the filters, in particular in terms of, for example, the surface roughness.

  7. Filtration and Leach Testing for PUREX Cladding Sludge and REDOX Cladding Sludge Actual Waste Sample Composites

    Energy Technology Data Exchange (ETDEWEB)

    Shimskey, Rick W.; Billing, Justin M.; Buck, Edgar C.; Casella, Amanda J.; Crum, Jarrod V.; Daniel, Richard C.; Draper, Kathryn E.; Edwards, Matthew K.; Hallen, Richard T.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Swoboda, Robert G.

    2009-03-02

    of gibbsite, and its impact on filtration. The initial sample was diluted with a liquid simulant to simulate the receiving concentration of retrieved tank waste into the UFP2 vessel (< 10 wt% undissolved solids). Filtration testing was performed on the dilute waste sample and dewatered to a higher solids concentration. Filtration testing was then performed on the concentrated slurry. Afterwards, the slurry was caustic leached to remove aluminum present in the undissolved solid present in the waste. The leach was planned to simulate leaching conditions in the UFP2 vessel. During the leach, slurry supernate samples were collected to measure the dissolution rate of aluminum in the waste. After the slurry cooled down from the elevated leach temperature, the leach liquor was dewatered from the solids. The remaining slurry was rinsed and dewatered with caustic solutions to remove a majority of the dissolved aluminum from the leached slurry. The concentration of sodium hydroxide in the rinse solutions was high enough to maintain the solubility of the aluminum in the dewatered rinse solutions after dilution of the slurry supernate. Filtration tests were performed on the final slurry to compare to filtration performance before and after caustic leaching.

  8. Sequential injection approach for simultaneous determination of ultratrace plutonium and neptunium in urine with accelerator mass spectrometry.

    Science.gov (United States)

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Lachner, Johannes; Christl, Marcus; Xu, Yihong

    2013-09-17

    An analytical method was developed for simultaneous determination of ultratrace level plutonium (Pu) and neptunium (Np) using iron hydroxide coprecipitation in combination with automated sequential injection extraction chromatography separation and accelerator mass spectrometry (AMS) measurement. Several experimental parameters affecting the analytical performance were investigated and compared including sample preboiling operation, aging time, amount of coprecipitating reagent, reagent for pH adjustment, sedimentation time, and organic matter decomposition approach. The overall analytical results show that preboiling and aging are important for obtaining high chemical yields for both Pu and Np, which is possibly related to the aggregation and adsorption behavior of organic substances contained in urine. Although the optimal condition for Np and Pu simultaneous determination requires 5-day aging time, an immediate coprecipitation without preboiling and aging could also provide fairly satisfactory chemical yields for both Np and Pu (50-60%) with high sample throughput (4 h/sample). Within the developed method, (242)Pu was exploited as chemical yield tracer for both Pu and Np isotopes. (242)Pu was also used as a spike in the AMS measurement for quantification of (239)Pu and (237)Np concentrations. The results show that, under the optimal experimental condition, the chemical yields of (237)Np and (242)Pu are nearly identical, indicating the high feasibility of (242)Pu as a nonisotopic tracer for (237)Np determination in real urine samples. The analytical method was validated by analysis of a number of urine samples spiked with different levels of (237)Np and (239)Pu. The measured values of (237)Np and (239)Pu by AMS exhibit good agreement (R(2) ≥ 0.955) with the spiked ones confirming the reliability of the proposed method.

  9. DESTRUCTION OF XENOBIOTICS BY CULTURE FILTRATE FROM XYLOTROPHIC BASIDIOMYCETES

    Directory of Open Access Journals (Sweden)

    Fedotov O. V.

    2015-12-01

    Full Text Available The article deals with the efficiency of pollutants biodegradation by xylotrophic basidiomycetes submerged cultures grown on standard glucose-peptone medium (GPM. The efficiency of pollutants biodegradation was determined by the model compound – dye Methyl Orange. The purpose of the work is screening of 19 species 81 strains xylotrophic basidiomycetes cultures on the indicator of the dye oxidative degradation efficiency and exploring the possibility of induction of this indicator by modifying the culture medium. The biodegradation efficiency was determined by following method. Assigned amount of culture filtrate (experiment or medium (control was added to the 0.001% solution of Methyl Orange in sodium acetate buffer. pH of the reaction mixture was 4.4 units. Samples were incubated at +40°C for 48 hours. Then pH of the reaction mixture was set up at 3.1 units using sodium acetate buffer and the optical density of solutions at a wavelength of 506 nm was measured. The efficiency of biodegradation was calculated by the difference of the optical density of control and experiment as a percentage. The most promising strains – F. velutipes F-1105, P. eryngii P-er, T. hirsuta Th-11 and D. quercina Dq-08 were selected. The composition of the glucose-peptone medium was modified for these strains by the introduction in the medium lignosulfonate, Tween 80, Kirk’s minerals solution and selecting the concentration of these components. According to the study for the purpose of pollutants degradation it is advisable to cultivate F. velutipes F-1105 strain on modified GPM, which further comprises at 1 l: lignosulfonate – 3.5 g; Tween 80 – 1.0 g, Kirk’s minerals solution – 70 ml; P. eryngii P-er strain – 5.0 g, 1.0 g, 70 ml; T. hirsuta Th-11 strain – 5.0 g, 1.0 g, 105 ml; and D. quercina Dq-08 strain – 6.5 g, 1.0 g, 105 ml, respectively. This allowed to increase the model compound degradation efficiency by the culture filtrate of strain F

  10. A stochastic model for filtration of particulate suspensions with incomplete pore plugging

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Santos, A; Bedrikovetsky, P. G.

    2007-01-01

    A population balance model for particulate suspension transport with capture of particles by porous medium accounting for complete and incomplete plugging of pores by retained particles is derived. The model accounts for pore space accessibility, due to restriction on finite size particle movement....... A closed system of governing stochastic equations determines the evolution of size distributions for suspended particles and pores. Its averaging results in the closed system of hydrodynamic equations accounting for permeability and porosity reduction due to plugging. The problem of deep bed filtration...... of a single particle size suspension through a single pore size medium where a pore can be completely plugged by two particles allows for an exact analytical solution. The phenomenological deep bed filtration model follows from the analytical solution....

  11. HGMF of 10-L solutions

    Energy Technology Data Exchange (ETDEWEB)

    Larkin, K.A.

    1994-08-14

    This test plan describes the activities associated with the High Gradient Magnetic Filtration (HGMF) of plutonium-bearing solutions (10-L). The 10-L solutions were received from Argonne National Laboratories in 1972, are highly acidic, and are considered unstable. The purpose of the testing is to show that HGMF is an applicable method of removing plutonium precipitates from solution. The plutonium then can be stored safely in a solid form.

  12. Transfer and transport of aluminum in filtration unit

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Aluminum salt coagulants were used prevalently in various water works. In this article, the effects of filtration on residual aluminum concentration and species distribution were researched by determining the concentration of different Aluminum species before and after single layer filter, double layer filter, and membrane filtration units. In the research, size exclusion chromatography (SEC) was used to separate colloidal and soluble aluminum, ion exchange chromatography (IEC) was used to separate organic and inorganic aluminum, and inductivity coupled plasma-atomic emission spectrometry (ICP-AES) was used to determine the aluminum concentration. The results showed that the rapid filtration process had the ability of removing residual aluminum from coagulant effluent water, and that double layer filtration was more effective in residual aluminum removal than single layer filtration, while Nano filtration was more effective than micro filtration. It was found that when the residual aluminum concentration was below 1mg/L in sediment effluent, the residual aluminum concentration in treated water was above 0.2 mg/L. The direct rapid filtration process mainly removed the suspended aluminum. The removal of soluble and colloidal aluminum was always less than 10% and the natural small particles that adsorbed the amount of soluble or small particles aluminum on their surface were difficult to be removed in this process. Micro filtration and nano filtration were good technologies for removing aluminum; the residual aluminum concentration in the effluent was less than 0.05 mg/L.

  13. Effects of fasting and/or oxidizing and reducing agents on absorption of neptunium from the gastrointestinal tract of mice and adult or neonatal rats.

    Science.gov (United States)

    Sullivan, M F; Ruemmler, P S; Ryan, J L

    1984-12-01

    Neptunium-237(V) nitrate was administered by gavage to groups of fed or fasted adult and 5-day-old rats. Some groups also received the oxidants quinhydrone or ferric iron, and others received the reducing agent ferrous iron. Adult mice received ferric or ferrous iron and 235Np. When the adult rats were killed at 7 days after gavage, measurements showed that, compared with rats that were fed, a 24-hr fast caused a fivefold increase in 237Np absorption and retention. Both quinhydrone and ferric iron caused an even greater increase in absorption in both fed and fasted rats. Ferrous iron, on the other hand, decreased absorption in fasted rats to values lower than those obtained in fed rats. Similar results were obtained in mice treated with 235Np and either ferric or ferrous iron. The highest absorption obtained after gavage of ferric iron to fasted rats and mice was about two orders of magnitude higher than the value obtained in animals that were fed before gavage. The effects of ferric and ferrous iron on neptunium absorption by neonatal rats were similar to their effects on adult animals but of lesser magnitude. These results are consistent with the hypothesis that Np(V), when given in small mass quantities to fed animals, is reduced in the gastrointestinal tract to Np(IV), which is less well absorbed than Np(V).

  14. Martingale representation property in progressively enlarged filtrations

    CERN Document Server

    Jeanblanc, M

    2012-01-01

    Consider $\\mathbb{G}$ the progressive enlargement of a filtration $\\mathbb{F}$ with a random time $\\tau$. Assuming that, in $\\mathbb{F}$, the martingale representation property holds, we examine conditions under which the martingale representation property holds also in $\\mathbb{G}$. It is noted that the classical results on this subject are no more sufficient to deal with all examples coming from credit risk modeling. In this paper, we introduce a new methodology which extends the various classical results and applies on recent examples.

  15. Evaluation of the effectiveness of the filtration leaching for uranium recovery from uranium ore

    OpenAIRE

    2015-01-01

    The physical and chemical processes taking place in filtration leaching of uranium from uranium ore sample by sulphuric acid solution have been studied by modern physico-chemical methods (X-ray diffraction, scanning electron spectroscopy, electron probe microanalysis, optical emission spectroscope, ICP OES). Column leaching test was carried out for ore samples obtained from a uranium in-situ leaching (ISL) mining site using deluted sulphuricacid to study the evolution of various elements conc...

  16. Controlling the rejection of protein during membrane filtration by adding selected polyelectrolytes

    DEFF Research Database (Denmark)

    Pinelo, Manuel; Ferrer Roca, Carme; Meyer, Anne S.

    2012-01-01

    Electrostatic interactions among the charged groups on proteins and/or between proteins and other solutes significantly affect the aggregation/deposition phenomena that induce fouling and decrease permeate flux during membrane purification of proteins. Such interactions can be turned into an adva...... help enhance the performance of membrane filtration for fractionation/purification of a target protein by significantly reducing fouling and modifying rejection/selectivity....

  17. Filtration-guided assembly for patterning one-dimensional nanostructures

    Science.gov (United States)

    Zhang, Yaozhong; Wang, Chuan; Yeom, Junghoon

    2017-04-01

    Tremendous progress has been made in synthesizing various types of one-dimensional (1D) nanostructures (NSs), such as nanotubes and nanowires, but some technical challenges still remain in the deterministic assembly of the solution-processed 1D NSs for device integration. In this work we investigate a scalable yet inexpensive nanomaterial assembly method, namely filtration-guided assembly (FGA), to place nanomaterials into desired locations as either an individual entity or ensembles, and form functional devices. FGA not only addresses the assembly challenges but also encompasses the notion of green nanomanufacturing, maximally utilizing nanomaterials and eliminating a waste stream of nanomaterials into the environment. FGA utilizes selective filtration of 1D NSs through the open windows on the nanoporous filter membrane whose surface is patterned by a polymer mask for guiding the 1D NS deposition. The modified soft-lithographic technique called blanket transfer (BT) is employed to create the various photoresist patterns of sub-10-micron resolution on the nanoporous filter membrane like mixed cellulose acetate. We use single-walled carbon nanotubes (SWCNTs) as a model 1D NS and demonstrate the fabrication of an array pattern of homogeneous 1D NS network films over an area of 20 cm2 within 10 min. The FGA-patterned SWCNT network films are transferred onto the substrate using the adhesive-based transfer technique, and show the highly uniform film thickness and resistance measurements across the entire substrate. Finally, the electrical performance of the back-gated transistors made from the FGA and transfer method of 95% pure SWCNTs is demonstrated.

  18. Microfluidic filtration system to isolate extracellular vesicles from blood.

    Science.gov (United States)

    Davies, Ryan T; Kim, Junho; Jang, Su Chul; Choi, Eun-Jeong; Gho, Yong Song; Park, Jaesung

    2012-12-21

    Extracellular vesicles are released by various cell types, particularly tumor cells, and may be potential targets for blood-based cancer diagnosis. However, studies performed on blood-borne vesicles to date have been limited by lack of effective, standardized purification strategies. Using in situ prepared nanoporous membranes, we present a simple strategy employing a microfluidic filtration system to isolate vesicles from whole blood samples. This method can be applied to purify nano-sized particles from blood allowing isolation of intact extracellular vesicles, avoiding the need for laborious and potentially damaging centrifugation steps or overly specific antibody-based affinity purification. Porous polymer monoliths were integrated as membranes into poly(methyl methacrylate) microfluidic chips by benchtop UV photopolymerization through a mask, allowing precise positioning of membrane elements while preserving simplicity of device preparation. Pore size could be manipulated by changing the ratio of porogenic solvent to prepolymer solution, and was tuned to a size proper for extraction of vesicles. Using the membrane as a size exclusion filter, we separated vesicles from cells and large debris by injecting whole blood under pressure through the microfluidic device. To enhance isolation purity, DC electrophoresis was employed as an alternative driving force to propel particles across the filter and increase the separation efficiency of vesicles from proteins. From the whole blood of melanoma-grown mice, we isolated extracellular vesicles and performed RT-PCR to verify their contents of RNA. Melan A mRNA derived from melanoma tumor cells were found enriched in filtered samples, confirming the recovery of vesicles via their cargo. This filtration system can be incorporated into other on-chip processes enabling integrated sample preparation for the downstream analysis of blood-based extracellular vesicles.

  19. Fast Filtration of Bacterial or Mammalian Suspension Cell Cultures for Optimal Metabolomics Results.

    Science.gov (United States)

    Bordag, Natalie; Janakiraman, Vijay; Nachtigall, Jonny; González Maldonado, Sandra; Bethan, Bianca; Laine, Jean-Philippe; Fux, Elie

    2016-01-01

    The metabolome offers real time detection of the adaptive, multi-parametric response of the organisms to environmental changes, pathophysiological stimuli or genetic modifications and thus rationalizes the optimization of cell cultures in bioprocessing. In bioprocessing the measurement of physiological intracellular metabolite levels is imperative for successful applications. However, a sampling method applicable to all cell types with little to no validation effort which simultaneously offers high recovery rates, high metabolite coverage and sufficient removal of extracellular contaminations is still missing. Here, quenching, centrifugation and fast filtration were compared and fast filtration in combination with a stabilizing washing solution was identified as the most promising sampling method. Different influencing factors such as filter type, vacuum pressure, washing solutions were comprehensively tested. The improved fast filtration method (MxP® FastQuench) followed by routine lipid/polar extraction delivers a broad metabolite coverage and recovery reflecting well physiological intracellular metabolite levels for different cell types, such as bacteria (Escherichia coli) as well as mammalian cells chinese hamster ovary (CHO) and mouse myeloma cells (NS0).The proposed MxP® FastQuench allows sampling, i.e. separation of cells from medium with washing and quenching, in less than 30 seconds and is robustly designed to be applicable to all cell types. The washing solution contains the carbon source respectively the 13C-labeled carbon source to avoid nutritional stress during sampling. This method is also compatible with automation which would further reduce sampling times and the variability of metabolite profiling data.

  20. Evaluation of the effectiveness of the filtration leaching for uranium recovery from uranium ore

    Directory of Open Access Journals (Sweden)

    Bolat Uralbekov

    2015-09-01

    Full Text Available The physical and chemical processes taking place in filtration leaching of uranium from uranium ore sample by sulphuric acid solution have been studied by modern physico-chemical methods (X-ray diffraction, scanning electron spectroscopy, electron probe microanalysis, optical emission spectroscope, ICP OES. Column leaching test was carried out for ore samples obtained from a uranium in-situ leaching (ISL mining site using deluted sulphuricacid to study the evolution of various elements concentration in the pregnant leach solution. It has been shown that the uranium in pregnant solutions appears by dissolution of calcium and magnesium carbonates and uranium minerals as well. It was found the decreasing of filtration coefficient from 0.099 m day-1 to 0.082 m day-1, due to the presence of mechanical and chemical mudding. Partial extraction of uranium (85% from the ore has been explained by the slow diffusion of sulfuric acid to the uranium minerals locates in the cracks of silicate minerals. It was concluded that the studied uranium ore sample according to adverse geotechnical parameters is not suitable for uranium extraction by filtration leaching.

  1. Design and Characterization of Electrospun Polyamide Nanofiber Media for Air Filtration Applications

    Directory of Open Access Journals (Sweden)

    Jonas Matulevicius

    2014-01-01

    Full Text Available Electrospun polyamide 6 (PA 6 and polyamide 6/6 (PA 6/6 nanofibers were produced in order to investigate their experimental characteristics with the goal of obtaining filtration relevant fiber media. The experimental design model of each PA nanofibers contained the following variables: polymer concentration, ratio of solvents, nanofiber media collection time, tip-to-collector distance, and the deposition voltage. The average diameter of the fibers, their morphology, basis weight, thickness, and resulting media solidity were investigated. Effects of each variable on the essential characteristics of PA 6/6 and PA 6 nanofiber media were studied. The comparative analysis of the obtained PA 6/6 and PA 6 nanofiber characteristics revealed that PA 6/6 had higher potential to be used in filtration applications. Based on the experimental results, the graphical representation—response surfaces—for obtaining nanofiber media with the desirable fiber diameter and basis weight characteristics were derived. Based on the modelling results the nanofiber filter media (mats were fabricated. Filtration results revealed that nanofiber filter media electrospun from PA6/6 8% (w/vol solutions with the smallest fiber diameters (62–66 nm had the highest filtration efficiency (PA6/6_30 = 84.9–90.9% and the highest quality factor (PA6/6_10 = 0.0486–0.0749 Pa−1.

  2. Hydrous iron oxide modified diatomite as an active filtration medium for phosphate capture.

    Science.gov (United States)

    Wang, Zhe; Lin, Yan; Wu, Deyi; Kong, Hainan

    2016-02-01

    A simple method to functionalize diatomite with hydrous iron oxide was attempted and its performance as a new active filtration material to remove and recover phosphate from water was investigated under varying solution conditions. The Langmuir phosphate adsorption capacity increased from 0.6 mgP/g for raw diatomite to 4.89, 14.71, 25.02 mgP/g for hydrous iron oxide modified diatomite (HIOMD), depending on the amount of iron loaded. Loading of hydrous iron oxide caused the increase in true and bulk density and a decline in filtration rate, but to a lesser extent. It was shown that the HIOMD product with suitable iron content could retain a good filtration performance with a greatly increased adsorption capacity for phosphate. The phosphate adsorption increased by decreasing pH and by increasing ionic strength at high pH levels. The adsorption process was interpreted by ligand exchange. Coexisting oxyanions of sulfate, nitrate, citrate, carbonate, silicate and humic acid showed different effects on phosphate fixation but it was presumed that their influence at their concentrations and pH levels commonly encountered in effluent or natural waters was limited, i.e., HIOMD had a reasonably good selectivity. Results in repeated adsorption, desorption and regeneration experiment showed that the adsorbed phosphate could be recovered and the material could be reused after regeneration. The column test showed that HIOMD could be potentially utilized as an adsorption filtration medium for phosphate removal and recovery from water.

  3. Determination of the modular elliptic function in problems of free-flow filtration

    Science.gov (United States)

    Anakhaev, K. N.

    2016-09-01

    The calculated dependences in elementary functions for determining the modular elliptic function λ(τ) =λ1 + iλ2 obtained on the basis of consecutive (six) conformal mappings of a curvilinear triangle to a complex half-plane are presented. Comparison of the values of λ(τ) from the proposed dependences with the results of the Hamel-Gunter exact analytical solution for the boundary contour of the curvilinear triangle, i.e., the real axis of the complex half-plane, gives a very close coincidence (with the largest error of ≤1%). The use of the complex values of the function λ(τ) for the entire internal region of the curvilinear triangle makes it possible to solve one of the most difficult problems of the theory of filtration (filtration through a rectangular dam) in the direct formulation and, for the first time, to construct the pattern of an equal filtration-rate field (the family of isotaches) over the entire internal region of the dam. In this case, the boundary values of filtration rates for special cases (along the sides and along the base of the dam) completely coincide with the results of the Masket exact analytical calculations.

  4. Study of the filtration performance of a plain wave fabric filter using response surface methodology.

    Science.gov (United States)

    Qian, Fuping; Wang, Haigang

    2010-04-15

    The gas-solid two-phase flows in the plain wave fabric filter were simulated by computational fluid dynamics (CFD) technology, and the warps and wefts of the fabric filter were made of filaments with different dimensions. The numerical solutions were carried out using commercial computational fluid dynamics (CFD) code Fluent 6.1. The filtration performances of the plain wave fabric filter with different geometry parameters and operating condition, including the horizontal distance, the vertical distance and the face velocity were calculated. The effects of geometry parameters and operating condition on filtration efficiency and pressure drop were studied using response surface methodology (RSM) by means of the statistical software (Minitab V14), and two second-order polynomial models were obtained with regard to the effect of the three factors as stated above. Moreover, the models were modified by dismissing the insignificant terms. The results show that the horizontal distance, vertical distance and the face velocity all play an important role in influencing the filtration efficiency and pressure drop of the plane wave fabric filters. The horizontal distance of 3.8 times the fiber diameter, the vertical distance of 4.0 times the fiber diameter and Reynolds number of 0.98 are found to be the optimal conditions to achieve the highest filtration efficiency at the same face velocity, while maintaining an acceptable pressure drop.

  5. Biophysical analysis of water filtration phenomenon in the roots of halophytes

    Science.gov (United States)

    Kim, Kiwoong; Lee, Sang Joon

    2015-11-01

    The water management systems of plants, such as water collection and water filtration have been optimized through a long history. In this point of view, new bio-inspired technologies can be developed by mimicking the nature's strategies for the survival of the fittest. In this study, the biophysical characteristics of water filtration process in the roots of halophytes are experimentally investigated in the plant hydrodynamic point of view. To understand the functional features of the halophytes 3D morphological structure of their roots are analyzed using advanced bioimaging techniques. The surface properties of the roots of halophytes are also examined Based on the quantitatively analyzed information, water filtration phenomenon in the roots is examined. Sodium treated mangroves are soaked in sodium acting fluorescent dye solution to trace sodium ions in the roots. In addition, in vitroexperiment is carried out by using the roots. As a result, the outermost layer of the roots filters out continuously most of sodium ions. This study on developing halophytes would be helpful for understanding the water filtration mechanism of the roots of halophytes and developing a new bio inspired desalination system. This research was financially supported by the National Research Foundation (NRF) of Korea (Contract grant number: 2008-0061991).

  6. Low-cost multi-stage filtration enhanced by coagulation-flocculation in upflow gravel filtration

    NARCIS (Netherlands)

    Sanchez, L.D.; Marin, L.M.; Visscher, J.T.; Rietveld, L.C.

    2012-01-01

    This paper assesses the operational and design aspects of coagulation and flocculation in upflow gravel filters (CF-UGF) in a multi-stage filtration (MSF) plant. This study shows that CF-UGF units improve the performance of MSF considerably, when the system operates with turbidity above 30 NTU. It s

  7. Dynamic optimization of a dead-end filtration trajectory : Non-ideal cake filtration

    NARCIS (Netherlands)

    Blankert, Bastiaan; Kattenbelt, Carolien; Betlem, Ben H.L.; Roffel, Brian

    2007-01-01

    A control strategy aimed at minimizing energy consumption is formulated for non-ideal dead-end cake filtration with an inside-out hollow fiber ultrafiltration membrane system. The non-ideal behavior was assumed to originate from cake compression, non-linear cake resistance and a variable pump effici

  8. Dynamic optimization of a dead-end filtration trajectory : Blocking filtration laws

    NARCIS (Netherlands)

    Blankert, Bastiaan; Betlem, Ben H.L.; Roffel, Brian

    2006-01-01

    An operating model for dead-end membrane filtration is proposed based on the well-known blocking laws. The resulting model contains three parameters representing, the operating strategy, the fouling mechanism and the fouling potential of the feed. The optimal control strategy is determined by minimi

  9. Neptunium(V) partitioning to uranium(VI) oxide and peroxide solids.

    Science.gov (United States)

    Douglas, Matthew; Clark, Sue B; Friese, Judah I; Arey, Bruce W; Buck, Edgar C; Hanson, Brady D

    2005-06-01

    Metaschoepite, [(UO2)8O2(OH)12] x 10H2O, and metastudtite, UO4 x 4H2O, are alteration phases anticipated in a spent nuclear fuel repository following the moist oxidation of UO2 on a geologic time scale. Dissolved concentrations and hence potential mobility of other radionuclides in the fuel, such as the neptunyl cation (NpO2+), will likely be determined by the extent of their partitioning into these U(VI) solids. 237Np is of particular interest due to its potential high mobility and long half-life (2.1 x 10(6) years.) In this study, metaschoepite has been precipitated and subsequently transformed to studtite in the presence of dissolved Np. The metaschoepite and studtite solids that formed initially contained dissolution studies of these solids at pH 6 demonstrate release of Np that exceeds congruent dissolution of U from metastudtite; furthermore, the released Np cation remains in solution. Thus, although the Np partitions into the metastudtite solid initially, it is released to solution over time, indicating that metastudtite is not likely to serve as a host solid for Np incorporation or sorption of the neptunyl cation on long time scales.

  10. Prediction Models for Plutonium, Strontium, Uranium and Neptunium Loading onto Monosodium Titanate (MST)

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F. F.; Hobbs, D. T.; Barnes, M. J.; Peters, T. B.; Fink, S. D.

    2005-07-11

    The DA isotherm parameters for U, Pu, Sr and Np have been updated to include additional data obtained since the original derivation. The DA isotherms were modified to include a kinetic function derived by Rahn to describe sorbate loading from the beginning of sorption up to equilibrium. The final functions describe both kinetic and thermodynamic sorption. We selected the Rahn function to describe radionuclide sorption because it originates from diffusion and absorption controlled sorption. An investigation of the thermal behavior of radionuclide sorption on MST as shown by this data revealed the sorption process is diffusion (or transport) controlled (in solution). Transport in solution can in theory be accelerated by vigorous mixing but the range of available mixing speed in the facility design will probably not be sufficient to markedly increase radionuclide sorption rate on MST from diffusion-controlled sorption. The laboratory studies included mixing energies hydraulically-scaled to match those of the Actinide Removal Process and these likely approximate the range of energies available in the Salt Waste Processing Facility.

  11. METC CFD simulations of hot gas filtration

    Energy Technology Data Exchange (ETDEWEB)

    O`Brien, T.J.

    1995-06-01

    Computational Fluid Dynamic (CFD) simulations of the fluid/particle flow in several hot gas filtration vessels will be presented. These simulations have been useful in designing filtration vessels and in diagnosing problems with filter operation. The simulations were performed using the commercial code FLUENT and the METC-developed code MFIX. Simulations of the initial configuration of the Karhula facility indicated that the dirty gas flow over the filter assemblage was very non-uniform. The force of the dirty gas inlet flow was inducing a large circulation pattern that caused flow around the candles to be in opposite directions on opposite sides of the vessel. By introducing a system of baffles, a more uniform flow pattern was developed. This modification may have contributed to the success of the project. Several simulations of configurations proposed by Industrial Filter and Pump were performed, varying the position of the inlet. A detailed resolution of the geometry of the candles allowed determination of the flow between the individual candles. Recent simulations in support of the METC/CeraMem Cooperative Research and Development Agreement have analyzed the flow in the vessel during the cleaning back-pulse. Visualization of experiments at the CeraMem cold-flow facility provided confidence in the use of CFD. Extensive simulations were then performed to assist in the design of the hot test facility being built by Ahlstrom/Pyropower. These tests are intended to demonstrate the CeraMem technology.

  12. Diatomite releases silica during spirit filtration.

    Science.gov (United States)

    Gómez, J; Gil, M L A; de la Rosa-Fox, N; Alguacil, M

    2014-09-15

    The purpose of this study was to ascertain whether diatomite is an inert filter aid during spirit filtration. Surely, any compound with a negative effect on the spirit composition or the consumer's health could be dissolved. In this study different diatomites were treated with 36% vol. ethanol/water mixtures and the amounts and structures of the extracted compounds were determined. Furthermore, Brandy de Jerez was diatomite- and membrane-filtered at different temperatures and the silicon content was analysed. It was found that up to 0.36% by weight of diatomite dissolved in the aqueous ethanol and amorphous silica, in the form of hollow spherical microparticles, was the most abundant component. Silicon concentrations in Brandy de Jerez increased by up to 163.0% after contact with diatomite and these changes were more marked for calcined diatomite. In contrast, reductions of more than 30% in silicon concentrations were achieved after membrane filtration at low temperatures. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Tailoring Supramolecular Nanofibers for Air Filtration Applications.

    Science.gov (United States)

    Weiss, Daniel; Skrybeck, Dominik; Misslitz, Holger; Nardini, David; Kern, Alexander; Kreger, Klaus; Schmidt, Hans-Werner

    2016-06-15

    The demand of new materials and processes for nanofiber fabrication to enhance the performance of air filters is steadily increasing. Typical approaches to obtain nanofibers are based on top-down processes such as melt blowing, centrifugal spinning, and electrospinning of polymer materials. However, fabrication of polymer nanofibers is limited with respect to either a sufficiently high throughput or the smallest achievable fiber diameter. This study reports comprehensively on a fast and simple bottom-up process to prepare supramolecular nanofibers in situ inside viscose/polyester microfiber nonwovens. Here, selected small molecules of the materials class of 1,3,5-benzenetrisamides are employed. The microfiber-nanofiber composites exhibit a homogeneous nanofiber distribution and morphology throughout the entire nonwoven scaffold. Small changes in molecular structure and processing solvent have a strong influence on the final nanofiber diameter and diameter distribution and, consequently, on the filtration performance. Choosing proper processing conditions, microfiber-nanofiber composites with surprisingly high filtration efficiencies of particulate matter are obtained. In addition, the microfiber-nanofiber composite integrity at elevated temperatures was determined and revealed that the morphology of supramolecular nanofibers is maintained compared to that of the utilized polymer nonwoven.

  14. Renal filtration function in patients with gout

    Directory of Open Access Journals (Sweden)

    N. N. Kushnarenko

    2016-01-01

    Full Text Available Aim. To study circadian blood pressure (BP profile in patients with gout depending on the presence of arterial hypertension (HT and their relationship to the renal filtration function.Material and methods. Patients with gout (n=87 were included into the study. All the patients underwent ambulatory BP monitoring (ABPM with the assessment of circadian BP profile, determination of uric acid serum levels, glomerular filtration rate (GFR was evaluated by CKD-EPI method. Depending on GFR level, all the patients were divided into 2 groups - with renal dysfunction or without one.Results. ABPM revealed circadian BP dysregulation in 55% of gout patients both with HT and without HT. Chronic kidney disease (CKD was revealed in 72.4% of male patients, with the prevalence in patients with HT (76.6 vs 61%; p<0.001. Correlations between uric acid levels and some ABPM indicators and GFR were determined.Conclusion. Obtained data suggest the contribution of hyperuricemia in disorders of systemic and renal hemodynamics, leading to the early development of CKD.

  15. A study of dynamic filtration; Um estudo sobre filtracao dinamica

    Energy Technology Data Exchange (ETDEWEB)

    Girao, Joaquim Helder S. [PETROBRAS, Natal, RN (Brazil). Distrito de Perfuracao da Bacia Potiguar. Div. de Tecnicas de Perfuracao

    1989-12-31

    The problems that cause cost increase such as: formation damage and borehole swelling or caving lead us to study the filtration of the liquid part of formation drilling fluid. With the aim of comparing static and dynamic filtration rates, we developed a modest dynamic filtration equipment, consisting of a modified API filter, connected to reservoir by means of a positive injection pump. We carried out various tests, and the results were set in charts and tables. Through these, it is possible to notice how the static and dynamic filtration curves come apart for a same pressure value. We also evaluated the effects of circulation speed, starch concentration and counter pressure. This paper does not include calculations or mathematical models accounting for filtrate invasion radii, but it demonstrates, for example, that cleaning circulation will cause lower filtration rates at lower flows. (author) 5 refs., 11 figs., 14 tabs.

  16. Physicochemical interaction and its influence on deep bed filtration process.

    Science.gov (United States)

    Guo, Jin-long; Meng, Jun; Li, Gui-ping; Luan, Zhao-kun; Tang, Hong-xiao

    2004-01-01

    The capillary model was used to analyze the hydraulic conditions in the deep bed filtration process. The physicochemical interaction forces between the filter media and suspended particles and their influence on deep bed filtration process were also studied theoretically. Through the comparison of the hydraulic and physicochemical forces, the key influencing factors on the filtration process were proposed and investigated. Pilot study of the microflocculation deep bed filtration was carried out in the No. 9 Potable Water Treatment Plant of Beijing, and the experimental results of hydraulic head loss, particle distribution and entrapment were presented. The theoretical prediction was reasonably consistent with the experimental results under different conditions, which indicated that the regulation and control of micro-flocculation and deep bed filtration could be realized by the evaluation of the physicochemical interactions. Further theoretical and experimental research should be carried out to investigate the interaction mechanism and its application in the deep bed filtration and other cases.

  17. The effect of filter cake viscoelasticity on filtration

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard

    Wastewater is usually treated biologically, and a by-product from this treatment is waste-activated sludge with high water content. Sludge is therefore often filtrated to reduce the volume for handling and disposal, and to minimise the water content before incineration of the sludge. However...... a function of pressure as assumed when using the conventional models. Moreover, it is shown how the existing filtration models can be modified and the filtration process for activated sludge simulated....

  18. Analysis of fouling development under dynamic membrane filtration operation

    OpenAIRE

    Saleem, Mubashir; Alibardi, Luca; Cossu, Raffaello; Lavagnolo, Maria Cristina; Spagni, Alessandro

    2016-01-01

    This research is a contribution towards evaluating the appropriate fouling mechanism responsible for the flux decline under dynamic membrane (DM) filtration and its formation mechanism by using gravity-driven filtration in a specifically designed experimental setup. Series of extended short term filtration experiments were performed at varying operating conditions of mixed liquor suspended solids (MLSS) concentrations, trans-membrane pressures (TMP) and mesh pore sizes. Blocking models were a...

  19. Removal of cytomegalovirus DNA from donor blood by filtration.

    Science.gov (United States)

    Smith, K L; Cobain, T; Dunstan, R A

    1993-04-01

    Blood from five donors, previously shown to be positive for cytomegalovirus (CMV) DNA following polymerase chain reaction (PCR) amplification, was filtered through commercially available leucocyte filters. Analysis of pre- and post-filtration samples by PCR with ethidium bromide staining has shown that filtration was successful in removing CMV DNA from all samples. This is evidence that leucocyte filtration of red cell concentrates may greatly decrease the risk of CMV disease following transfusion to susceptible patients.

  20. Sensitive redox speciation of iron, neptunium, and plutonium by capillary electrophoresis hyphenated to inductively coupled plasma sector field mass spectrometry.

    Science.gov (United States)

    Graser, Carl-Heinrich; Banik, Nidhu Lal; Bender, Kerstin Anne; Lagos, Markus; Marquardt, Christian Michael; Marsac, Rémi; Montoya, Vanessa; Geckeis, Horst

    2015-10-01

    The long-term safety assessment for nuclear waste repositories requires a detailed understanding of actinide (geo)chemistry. Advanced analytical tools are required to gain insight into actinide speciation in a given system. The geochemical conditions in the vicinity of a nuclear repository control the redox state of radionuclides, which in turn has a strong impact on their mobility. Besides the long-lived radionuclides plutonium (Pu) and neptunium (Np), which are key elements in high level nuclear waste, iron (Fe) represents a main component in natural systems controlling redox-related geochemical processes. Measuring the oxidation state distribution for redox sensitive radionuclides and other metal ions is challenging at trace concentrations below the detection limit of most available spectroscopic methods (≥10(-6) M). Consequently, ultrasensitive new analytical techniques are required. Capillary electrophoresis (CE) is a suitable separation method for metal cations. CE hyphenated to inductively coupled plasma sector field mass spectrometry (CE-ICP-SF-MS) was used to measure the redox speciation of Pu (III, IV, V, VI), Np (IV, V, VI), and Fe (II, III) at concentrations lower than 10(-7) M. CE coupling and separation parameters such as sample gas pressure, make up flow rate, capillary position, auxiliary gas flow, as well as the electrolyte system were optimized to obtain the maximum sensitivity. We obtain detection limits of 10(-12) M for Np and Pu. The various oxidation state species of Pu and Np in different samples were separated by application of an acetate-based electrolyte system. The separation of Fe (II) and Fe (III) was investigated using different organic complexing ligands, EDTA, and o-phenanthroline. For the Fe redox system, a limit of detection of 10(-8) M was calculated. By applying this analytical system to sorption studies, we were able to underline previously published results for the sorption behavior of Np in highly diluted concentrations, and

  1. Understanding the interactions of neptunium and plutonium ions with graphene oxide: scalar-relativistic DFT investigations.

    Science.gov (United States)

    Wu, Qun-Yan; Lan, Jian-Hui; Wang, Cong-Zhi; Zhao, Yu-Liang; Chai, Zhi-Fang; Shi, Wei-Qun

    2014-11-06

    Due to the vast application potential of graphene oxide (GO)-based materials in nuclear waste processing, it is of pivotal importance to investigate the interaction mechanisms between actinide cations such as Np(V) and Pu(IV, VI) ions and GO. In this work, we have considered four types of GOs modified by hydroxyl, carboxyl, and carbonyl groups at the edge and epoxy group on the surface, respectively. The structures, bonding nature, and binding energies of Np(V) and Pu(IV, VI) complexes with GOs have been investigated systematically using scalar-relativistic density functional theory (DFT). Geometries and harmonic frequencies suggest that Pu(IV) ions coordinate more easily with GOs compared to Np(V) and Pu(VI) ions. NBO and electron density analyses reveal that the coordination bond between Pu(IV) ions and GO possesses more covalency, whereas for Np(V) and Pu(VI) ions electrostatic interaction dominates the An-OG bond. The binding energies in aqueous solution reveal that the adsorption abilities of all GOs for actinide ions follow the order of Pu(IV) > Pu(VI) > Np(V), which is in excellent agreement with experimental observations. It is expected that this study can provide useful information for developing more efficient GO-based materials for radioactive wastewater treatment.

  2. Dynamical Systems, Cytokine Storms, and Blood Filtration

    Science.gov (United States)

    Foster, Glenn; Hubler, Alfred

    2008-03-01

    Various infections and non-infectious diseases can trigger immune cells and the proteins (cytokines) the cells use to communicate with each other to be caught in a positive feedback loop; this ``cytokine storm'' is frequently fatal. By examining the network of cytokine-immune cell interactions we will illustrate why anti-mediator drugs have been generally ineffective in stopping this feedback. A more effective approach may be to try and reduce interactions by dampening many signals at once by filtering the cytokines out of the blood directly (think dialysis). We will argue that feedback on an out of control nonlinear dynamical system is easier to understand than its normal healthy state and apply filtration to a toy model of immune response.

  3. Pattern recognition using inverse resonance filtration

    CERN Document Server

    Sofina, Olga; Kvetnyy, Roman

    2010-01-01

    An approach to textures pattern recognition based on inverse resonance filtration (IRF) is considered. A set of principal resonance harmonics of textured image signal fluctuations eigen harmonic decomposition (EHD) is used for the IRF design. It was shown that EHD is invariant to textured image linear shift. The recognition of texture is made by transfer of its signal into unstructured signal which simple statistical parameters can be used for texture pattern recognition. Anomalous variations of this signal point on foreign objects. Two methods of 2D EHD parameters estimation are considered with the account of texture signal breaks presence. The first method is based on the linear symmetry model that is not sensitive to signal phase jumps. The condition of characteristic polynomial symmetry provides the model stationarity and periodicity. Second method is based on the eigenvalues problem of matrices pencil projection into principal vectors space of singular values decomposition (SVD) of 2D correlation matrix....

  4. Gravity filtration of suspensions: permeability effects

    Science.gov (United States)

    Soori, Tejaswi; Wang, Mengyu; Ward, Thomas

    2015-11-01

    This paper examines the filtration rates of mono-modal suspensions as a function of time and a cake layer builds up through theory and experimentation. Darcy's Law, which describes fluid flow through porous media, was applied along with the Kynch theory of sedimentation, which provides the basis for analyzing low concentration (ϕ filter media. A CCD camera was used to capture images of the cake formation and fluid drainage processes, and subsequent image and theoretical analysis found the fluid flow experienced a constant pressure loss due to the permeability of the filter media, whereas the experienced pressure loss due to the cake formation varies as a function of time, ϕ and d. The rate of cake formation was also found to be independent of ϕ but dependent on d which can be attributed to a change in porosity affecting permeability. Studies on similar systems with multi-modal suspensions are in-progress.

  5. Influence of the redox state on the neptunium sorption under alkaline conditions. Batch sorption studies on titanium dioxide and calcium silicate hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Tits, Jan; Laube, Andreas; Wieland, Erich [Paul Scherrer Institute (PSI), Villigen (Switzerland). Lab. for Waste Management; Gaona, Xavier [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany). Inst. for Nuclear Waste Disposal

    2014-07-01

    Wet chemistry experiments were carried out to investigate the effect of the redox state and aqueous speciation on the uptake of neptunium by titanium dioxide (TiO{sub 2}) and by calcium silicate hydrates (C-S-H) under alkaline conditions. TiO{sub 2} was chosen as a reference sorbent to determine the surface complexation behaviour of neptunium under alkaline conditions. C-S-H phases are important constituents of cement and concrete. They may contribute significantly to radionuclide retention due to their high recrystallization rates making incorporation the dominating sorption mechanism for many radionuclides (e.g. the actinides) on these materials. The sorption of neptunium on both solids was found to depend strongly on the degree of hydrolysis. On TiO{sub 2}R{sub d} values for Np(IV), Np(V) and Np(VI) are identical at pH = 10 and decrease with progressing hydrolysis in case of Np(V) and Np(VI). On C-S-H phases, R{sub d} values for the three redox states are also identical at pH = 10. While the R{sub d} values for Np(VI) sorption on C-S-H phases decrease with progressing hydrolysis, the R{sub d} values for Np(IV) and Np(V) sorption are not affected by the pH. In addition to the effect of hydrolysis, the presence of Ca is found to promote Np(V) and Np(VI) sorption on TiO{sub 2} whereas on C-S-H phases, the present wet chemistry data do not give unambiguous evidence. Thus, the aqueous speciation appears to have a similar influence on the sorption of the actinides on both types of solids despite the different sorption mechanism. The similar R{sub d} values for Np(IV,V,VI) sorption at pH = 10 can be explained qualitatively by invoking inter-ligand electrostatic repulsion between OH groups in the coordination sphere of Np(V) and Np(VI). This mechanism was proposed earlier in the literature for the prediction of actinide complexation constants with inorganic ligands. A limiting coordination number for each Np redox state, resulting from the inter-ligand electrostatic

  6. Some aspects of applying nanostructured materials in air filtration, water filtration and electrical engineering

    Science.gov (United States)

    Kimmer, Dusan; Vincent, Ivo; Lovecka, Lenka; Kazda, Tomas; Giurg, Adam; Skorvan, Ondrej

    2017-05-01

    Nanostructures prepared from nanofibres and nanostructured composites prepared from nanofibres and fillers are gradually becoming increasingly demanded materials for applications in various industrial branches connected with catalysis, environment protection (air filtration, waste water treatment, sound absorption), in biological engineering, electronics (battery separators, electrode materials), etc. Selected applications of these materials prepared in the company SPUR a.s. are summed up in the following presentation.

  7. Life Support Filtration System Trade Study for Deep Space Missions

    Science.gov (United States)

    Agui, Juan H.; Perry, Jay L.

    2017-01-01

    The National Aeronautics and Space Administrations (NASA) technical developments for highly reliable life support systems aim to maximize the viability of long duration deep space missions. Among the life support system functions, airborne particulate matter filtration is a significant driver of launch mass because of the large geometry required to provide adequate filtration performance and because of the number of replacement filters needed to a sustain a mission. A trade analysis incorporating various launch, operational and maintenance parameters was conducted to investigate the trade-offs between the various particulate matter filtration configurations. In addition to typical launch parameters such as mass, volume and power, the amount of crew time dedicated to system maintenance becomes an increasingly crucial factor for long duration missions. The trade analysis evaluated these parameters for conventional particulate matter filtration technologies and a new multi-stage particulate matter filtration system under development by NASAs Glenn Research Center. The multi-stage filtration system features modular components that allow for physical configuration flexibility. Specifically, the filtration system components can be configured in distributed, centralized, and hybrid physical layouts that can result in considerable mass savings compared to conventional particulate matter filtration technologies. The trade analysis results are presented and implications for future transit and surface missions are discussed.

  8. Vibrating membrane filtration as improved technology for microalgae dewatering.

    Science.gov (United States)

    Nurra, Claudia; Clavero, Ester; Salvadó, Joan; Torras, Carles

    2014-04-01

    The effect of shear-enhanced filtration by vibratory process in microalgae dewatering is presented in this paper. The aim of this research was to investigate the technical performance and improvement of vibrating membrane filtration compared with conventional tangential cross-flow filtration in microalgae concentration. An industrial-scale available commercial set-up was used. Several membrane materials as polyethersulfone, polyacrylonitrile, etc., and mean pore sizes (from 7000Da to 0.2μm) were tested and compared in both filtration set-ups. Experiments were carried-out with Nannochloropsis gaditana and Phaeodactylum tricornutum microalgae. It has been demonstrated that, even if the choice of the membrane depends on its cut-off, its material and the type of microalgae filtrated, dynamic filtration is always the best technology over a conventional one. If with conventional filtration permeability values were in the vicinity of 10L/h/m(2)/bar in steady state phase, with dynamic filtration these values increased to 30L/h/m(2)/bar or more.

  9. Analysis of the Medium Resistance for Constant Pressure Filtration

    Institute of Scientific and Technical Information of China (English)

    吴燕翔; 王碧玉

    2004-01-01

    A mathematical model for constant pressure filtration is established. The distribution of hydraulic pressure within the cake and the medium resistance are measured. The medium resistance Rm is calculated from the suppositional filtration time Ore. It is demonstrated that Rm is nearly a constant for a given filter cloth.

  10. Purification of contaminated water by filtration through porous glass

    Science.gov (United States)

    Wydeven, T.; Leban, M. I.

    1972-01-01

    Method for purifying water that is contaminated with mineral salts and soluble organic compounds is described. Method consists of high pressure filtration of contaminated water through stabilized porous glass membranes. Procedure for conducting filtration is described. Types of materials by percentage amounts removed from the water are identified.

  11. Filter aids influence on pressure drop across a filtration system

    Science.gov (United States)

    Hajar, S.; Rashid, M.; Nurnadia, A.; Ammar, M. R.; Hasfalina, C. M.

    2017-06-01

    Filter aids is commonly used to reduce pressure drop across air filtration system as it helps to increase the efficiency of filtration of accumulated filter cake. Filtration velocity is one of the main parameters that affect the performance of filter aids material. In this study, a formulated filter aids consisting of PreKot™ and activated carbon mixture (designated as PrekotAC) was tested on PTFE filter media under various filtration velocities of 5, 6, and 8 m/min at a constant material loading of 0.2 mg/mm2. Results showed that pressure drop is highly influenced by filtration velocity where higher filtration velocity leads to a higher pressure drop across the filter cake. It was found that PrekotAC performed better in terms of reducing the pressure drop across the filter cake even at the highest filtration velocity. The diversity in different particle size distribution of non-uniform particle size in the formulated PrekotAC mixture presents a higher permeability causes a lower pressure drop across the accumulated filter cake. The finding suggests that PrekotAC is a promising filter aids material that helps reducing the pressure drop across fabric filtration system.

  12. Scaling and particulate fouling in membrane filtration systems

    NARCIS (Netherlands)

    Boerlage, S.F.E.

    2001-01-01

    In the last decade, pressure driven membrane filtration processes; reverse osmosis, nano, ultra and micro-filtration have undergone steady growth. Drivers for this growth include desalination to combat water scarcity and the removal of various material from water to comply with increasingly stringen

  13. Scaling and particulate fouling in membrane filtration systems

    NARCIS (Netherlands)

    Boerlage, S.F.E.

    2001-01-01

    In the last decade, pressure driven membrane filtration processes; reverse osmosis, nano, ultra and micro-filtration have undergone steady growth. Drivers for this growth include desalination to combat water scarcity and the removal of various material from water to comply with increasingly

  14. Simulation of impaction filtration by a porous filter

    NARCIS (Netherlands)

    Ghazaryan, L.; Lopez Penha, D.J.; Geurts, B.J.; Stolz, S.; Winkelmann, C.; Vafai, K.

    2010-01-01

    We present a new numerical approach for estimating filtration through porous media from first principles. We numerically simulate particle motion as arises in a carrier gas flow. The filtration we look at occurs due to impaction of particles with obstructing surfaces that are contained in the solid

  15. Model and optimization of electromagnetic filtration of metals

    Directory of Open Access Journals (Sweden)

    S. Golak

    2013-04-01

    Full Text Available Electromagnetic buoyancy force causes the movement of non-conducive particles in a conducting liquid under electromagnetic field. The phenomenon allows filtration of small inclusions from molten metals. This paper presents a mathematical model of the filtration process under alternating electromagnetic field and the methodology for maximizing its efficiency.

  16. Physicochemical interaction and its influence on deep bed filtration process

    Institute of Scientific and Technical Information of China (English)

    GUO Jin-long; MENG Jun; LI GUI-ping; LUAN Zhao-kun; TANG Hong-xiao

    2004-01-01

    The capillary model was used to analyze the hydraulic conditions in the deep bed filtration process. Thephysicochemical interaction forces between the filter media and suspended particles and their influence on deep bedfiltration process were also studied theoretically. Through the comparison of the hydraulic and physicochemicalforces, the key influencing factors on the filtration process were proposed and investigated. Pilot study of the micro-flocculation deep bed filtration was carried out in the No. 9 Potable Water Treatment Plant of Beijing, and theexperimental results of hydraulic head loss, particle distribution and entrapment were presented. The theoreticalprediction was reasonably consistent with the experimental results under different conditions, which indicated that theregulation and control of micro-flocculation and deep bed filtration could be realized by the evaluation of thephysicochemical interactions. Further theoretical and experimental research should be carried out to investigate theinteraction mechanism and its application in the deep bed filtration and other cases.

  17. Screening culture filtrates of fungi for activity against Tylenchulus semipenetrans

    Energy Technology Data Exchange (ETDEWEB)

    Verdejo-Lucas, S.; Viera, A.; Stchigel, A. M.; Sorribas, F. J.

    2009-07-01

    Culture filtrates of 20 fungi isolated from citrus soils were screened for their activity against Tylenchulus semipenetrans in both in vitro and greenhouse tests. The filtrates of Talaromyces cyanescens (isolates 2-4 and 2-5), Paecilomyces lilacinus, Chaetomium robustum, Acremonium strictum, Engyodontium album, Myrothecium verrucaria, Emericella rugulosa, and Tarracomyces gigaspora consistently inhibited the motility of second-stage juveniles at various concentrations of the filtrate. Dose-response models were used to determine the filtrate concentration required to inhibit the motility of 50% of the juveniles (CI50). The culture filtrate of P. lilacinus showed the highest activity with a CI50 value of 58% that differed from that of C. robustum (CI50 = 68%), and A. strictum CI50 = 82%. The culture filtrates of P. lilacinus, E. album, and T. cyanescens 2-5 maintained their activity when autoclaved at 120 degree centigrade for 20 min. The autoclaved filtrate of T. cyanescens 2-4 was more effective at inhibiting juvenile motility (CI50 = 28%) than that of T. cyanescens 2-5 (CI50 = 80%), C. robustum (CI50 = 72 %) and P. lilacinus (CI50 = 72%). The culture filtrate of T. cyanescens 2-4 also inhibited egg hatching. Nematode reproduction on Cleopatra mandarin and Carrizo citrange were respectively reduced by the culture filtrate of P. lilacinus and the autoclaved filtrate of T. cyanescens 2-4. These results support the hypothesis that soil fungi may contribute to regulate nematode densities by the production of secondary metabolites with nematicidal activity. (Author) 30 refs.

  18. Filtrates and Residues: Ice Cream: Delicious Chemistry.

    Science.gov (United States)

    Martino, James

    1983-01-01

    An experiment involving preparation of ice cream is conducted after students complete units on solutions, atomic structure, molecular architecture, and bonding. The laboratory gives practical illustration of relation of physical properties to bond type and solution theory developed. Materials needed, procedures used, and questions asked are…

  19. Filtrates and Residues: Ice Cream: Delicious Chemistry.

    Science.gov (United States)

    Martino, James

    1983-01-01

    An experiment involving preparation of ice cream is conducted after students complete units on solutions, atomic structure, molecular architecture, and bonding. The laboratory gives practical illustration of relation of physical properties to bond type and solution theory developed. Materials needed, procedures used, and questions asked are…

  20. Preparation of Ag/HBP/PAN Nanofiber Web and Its Antimicrobial and Filtration Property

    Directory of Open Access Journals (Sweden)

    Li-Rong Yao

    2016-01-01

    Full Text Available To widen the application of nanofibers web in the field of medical health materials, a new Ag/amino-terminated hyperbranched polymer (HBP/polyacrylonitrile (PAN nanofiber web with excellent antimicrobial activity and filtration property was produced with Ag/HBP dispersion solution and PAN nanofiber. Ag/HBP dispersion solution was prepared with HBP as reducer and stabilizer, and Ag/HBP/PAN nanofiber was prepared by modifying electrospun PAN nanofiber with Ag/HBP aqueous solution. The characterization results showed that spherical Ag nanoparticles were prepared and they had a narrow distribution in HBP aqueous solution. The results of Ag/HBP/PAN nanofiber characterized with SEM and EDS showed that the content of silver nanoparticles on the surface of PAN nanofiber was on the increase when the treating temperature rose. The bacterial reduction rates of HBP-treated PAN nanofiber against S. aureus and E. coli were about 89%, while those of the Ag/HBP/PAN nanofiber against S. aureus and E. coli were 99.9% and 99.96%, respectively, due to the cooperative effects from the amino groups in HBP and Ag nanoparticles. Moreover, the small pores and high porosity in Ag/HBP/PAN nanofiber web resulted in high filtration efficiency (99.9% for removing smaller particles (0.1 μm~0.7 μm, which was much higher than that of the gauze mask.

  1. Sorghum genome sequencing by methylation filtration.

    Directory of Open Access Journals (Sweden)

    Joseph A Bedell

    2005-01-01

    Full Text Available Sorghum bicolor is a close relative of maize and is a staple crop in Africa and much of the developing world because of its superior tolerance of arid growth conditions. We have generated sequence from the hypomethylated portion of the sorghum genome by applying methylation filtration (MF technology. The evidence suggests that 96% of the genes have been sequence tagged, with an average coverage of 65% across their length. Remarkably, this level of gene discovery was accomplished after generating a raw coverage of less than 300 megabases of the 735-megabase genome. MF preferentially captures exons and introns, promoters, microRNAs, and simple sequence repeats, and minimizes interspersed repeats, thus providing a robust view of the functional parts of the genome. The sorghum MF sequence set is beneficial to research on sorghum and is also a powerful resource for comparative genomics among the grasses and across the entire plant kingdom. Thousands of hypothetical gene predictions in rice and Arabidopsis are supported by the sorghum dataset, and genomic similarities highlight evolutionarily conserved regions that will lead to a better understanding of rice and Arabidopsis.

  2. Capturing phosphates with iron enhanced sand filtration.

    Science.gov (United States)

    Erickson, Andrew J; Gulliver, John S; Weiss, Peter T

    2012-06-01

    Most treatment practices for urban runoff capture pollutants such as phosphorus by either settling or filtration while dissolved phosphorus, typically as phosphates, is untreated. Dissolved phosphorus, however, represents an average 45% of total phosphorus in stormwater runoff and can be more than 95%. In this study, a new stormwater treatment technology to capture phosphate, called the Minnesota Filter, is introduced. The filter comprises iron filings mixed with sand and is tested for phosphate removal from synthetic stormwater. Results indicate that sand mixed with 5% iron filings captures an average of 88% phosphate for at least 200 m of treated depth, which is significantly greater than a sand filter without iron filings. Neither incorporation of iron filings into a sand filter nor capture of phosphates onto iron filings in column experiments had a significant effect on the hydraulic conductivity of the filter at mixtures of 5% or less iron by weight. Field applications with up to 10.7% iron were operated over 1 year without detrimental effects upon hydraulic conductivity. A model is applied and fit to column studies to predict the field performance of iron-enhanced sand filters. The model predictions are verified through the predicted performance of the filters in removing phosphates in field applications. Practical applications of the technology, both existing and proposed, are presented so stormwater managers can begin implementation.

  3. Estimating Glomerular Filtration Rate in Older People

    Directory of Open Access Journals (Sweden)

    Sabrina Garasto

    2014-01-01

    Full Text Available We aimed at reviewing age-related changes in kidney structure and function, methods for estimating kidney function, and impact of reduced kidney function on geriatric outcomes, as well as the reliability and applicability of equations for estimating glomerular filtration rate (eGFR in older patients. CKD is associated with different comorbidities and adverse outcomes such as disability and premature death in older populations. Creatinine clearance and other methods for estimating kidney function are not easy to apply in older subjects. Thus, an accurate and reliable method for calculating eGFR would be highly desirable for early detection and management of CKD in this vulnerable population. Equations based on serum creatinine, age, race, and gender have been widely used. However, these equations have their own limitations, and no equation seems better than the other ones in older people. New equations specifically developed for use in older populations, especially those based on serum cystatin C, hold promises. However, further studies are needed to definitely accept them as the reference method to estimate kidney function in older patients in the clinical setting.

  4. Pulmonary interstitial compliance and microvascular filtration coefficient.

    Science.gov (United States)

    Goldberg, H S

    1980-08-01

    Static and dynamic properties governing the fluid movement into the pulmonary interstitium were examined in isolated canine lobes. The system was driven by altering intravascular presure (Piv) when the lobe was isogravimetric (change in weight (W) = 0) and allowing the lobe to become isogravimetric again. By making use of an analogy to charging a capacitor across a resistor, calculation of the filtration coefficient for transvascular fluid movement (KF) and determination of the pressure-volume relationship of the pulmonary interstitial space (Pis-Vis), with a minimum of untested assumptions, was possible. KF was found to be the same for fluid moving out of or into the intravascular space, and when the relationship between Piv and alveolar pressure (PAlv) was constant, KF was independent of transpulmonary pressure (PL). When PAlv exceeded Piv, changes in Piv did not influence KF, suggesting no significant change in either surface area available for fluid transudation or vascular permeability. The Pis-Vis curve for increasing values of Vis and Pis is best described by an exponential relationhip and is independent of PL. However, the Pis-Vis curve with decreasing values of Vis and Pis is dependent on PL.

  5. Sorghum genome sequencing by methylation filtration.

    Science.gov (United States)

    Bedell, Joseph A; Budiman, Muhammad A; Nunberg, Andrew; Citek, Robert W; Robbins, Dan; Jones, Joshua; Flick, Elizabeth; Rholfing, Theresa; Fries, Jason; Bradford, Kourtney; McMenamy, Jennifer; Smith, Michael; Holeman, Heather; Roe, Bruce A; Wiley, Graham; Korf, Ian F; Rabinowicz, Pablo D; Lakey, Nathan; McCombie, W Richard; Jeddeloh, Jeffrey A; Martienssen, Robert A

    2005-01-01

    Sorghum bicolor is a close relative of maize and is a staple crop in Africa and much of the developing world because of its superior tolerance of arid growth conditions. We have generated sequence from the hypomethylated portion of the sorghum genome by applying methylation filtration (MF) technology. The evidence suggests that 96% of the genes have been sequence tagged, with an average coverage of 65% across their length. Remarkably, this level of gene discovery was accomplished after generating a raw coverage of less than 300 megabases of the 735-megabase genome. MF preferentially captures exons and introns, promoters, microRNAs, and simple sequence repeats, and minimizes interspersed repeats, thus providing a robust view of the functional parts of the genome. The sorghum MF sequence set is beneficial to research on sorghum and is also a powerful resource for comparative genomics among the grasses and across the entire plant kingdom. Thousands of hypothetical gene predictions in rice and Arabidopsis are supported by the sorghum dataset, and genomic similarities highlight evolutionarily conserved regions that will lead to a better understanding of rice and Arabidopsis.

  6. Filtration application from recycled expanded polystyrene.

    Science.gov (United States)

    Shin, C

    2006-10-01

    Water-in-oil emulsion with drop size less than 100 mum is difficult to separate. Coalescence filtration is economical and effective for separation of secondary dispersions. Coalescence performance depends on flow rate, bed depth, fiber surface properties, and drop size. The amount of surface area of the fibers directly affects the efficiency. A new recycling method was investigated in the previous work in which polystyrene (PS) sub-mum fibers were electro-spun from recycled expanded polystyrene (EPS). These fibers are mixed with micro glass fibers to modify the glass fiber filter media. The filter media are tested in the separation of water droplets from an emulsion of water droplets in oil. The experimental results in this work show that adding nanofibers to conventional micron sized fibrous filter media improves the separation efficiency of the filter media but also increases the pressure drop. An optimum in the performance occurs (significant increase in efficiency with minimal increase in pressure drop) with the addition of about 4% by mass of 500 nm diameter PS nanofibers to glass fibers for the filters.

  7. Efficient filtration system for paraffin-catalyst slurry separation

    Directory of Open Access Journals (Sweden)

    Khodagholi Mohammad Ali

    2013-01-01

    Full Text Available The filtration efficiency for separating liquid paraffin (or water from a slurry consisting of 25 weight% spherical alumina in a Slurry Bubble Column Reactor (SBCR comprised of a cylindrical tube of 10 cm diameter and 150 cm length was studied. Various differential pressures (ΔP were applied to two separate tubular sintered metal stainless steel filter elements with nominal pore size of 4 and 16μm. The experimental results disclosed that the rate of filtrations increased on applying higher differential pressure to the filter element. Albeit this phenomenon is limited to moderate ΔPs and for ΔP more than 1 bar is neither harmful nor helpful. The highest filtration rates at ΔPs higher than 1 bar were 170 and 248 ml/minute for 4 and 16μm respectively. Using water as the liquid in slurry the rate of filtration enhanced to 4 folds, and this issue reveals impact of viscosity on filtration efficiency clearly. In all situations, the total amount of particles present in the filtrate part never exceeded a few parts per million (ppm. The statistical analysis of the SEM image of the filtrate indicated that by applying higher pressure difference to the filter element the frequency percent of larger particle size increases. The operation of filter cake removing was performed with back flashing of 300 ml of clean liquid with pressures of 3-5 bar of N2 gas.

  8. THE STUDY OF THE FILTRATION EFFICIENCY OF FILTER MATERIAL

    Institute of Scientific and Technical Information of China (English)

    Jia Ruiqing; Wang Luping; Wu Xueping

    2000-01-01

    In this paper, the course of the filtration is analyzed.In order to study the filtration efficiency of the filter material, the computer program was edited.According to the results of the computer program, some important parameters of the filter material are discussed.It shows that the filtration efficiency is closely related to the diameter (d) and the size (b).In addition, by using these results and the computer program, we can analysis the relationship between the fiber structure and filter properties quantitatively.

  9. Herbal Extract Incorporated Nanofiber Fabricated by an Electrospinning Technique and its Application to Antimicrobial Air Filtration.

    Science.gov (United States)

    Choi, Jeongan; Yang, Byeong Joon; Bae, Gwi-Nam; Jung, Jae Hee

    2015-11-18

    Recently, with the increased attention to indoor air quality, antimicrobial air filtration techniques have been studied widely to inactivate hazardous airborne microorganisms effectively. In this study, we demonstrate herbal extract incorporated (HEI) nanofibers synthesized by an electrospinning technique and their application to antimicrobial air filtration. As an antimicrobial herbal material, an ethanolic extract of Sophora flavescens, which exhibits great antibacterial activity against pathogens, was mixed with the polymer solution for the electrospinning process. We measured various characteristics of the synthesized HEI nanofibers, such as fiber morphology, fiber size distribution, and thermal stability. For application of the electrospun HEI nanofibers, we made highly effective air filters with 99.99% filtration efficiency and 99.98% antimicrobial activity against Staphylococcus epidermidis. The pressure drop across the HEI nanofiber air filter was 4.75 mmH2O at a face air velocity of 1.79 cm/s. These results will facilitate the implementation of electrospun HEI nanofiber techniques to control air quality and protect against hazardous airborne microorganisms.

  10. MOBILIZATION, POISONING, AND FILTRATION OF F-CANYON TANK 804 SLUDGE

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M; Thomas Peters, T; Samuel Fink, S

    2006-05-04

    The Savannah River Site (SRS) Deactivation and Decommissioning (SDD) Organization is evaluating options to disposition the F-Canyon 800 series underground tanks (including removal of the sludge heels from these tanks) and requested assistance from Savannah River National Laboratory (SRNL) personnel to develop methods to effectively mobilize the sludge from these tanks (i.e., Tanks 804, 808, and 809). Because of the high plutonium content in Tank 804 (estimated to be as much as 1500 g), SDD needs to add a neutron poison to the sludge. They considered manganese and boron as potential poisons. Because of the large amount of manganese needed and the very slow filtration rate of the sludge/manganese slurry, SDD requested that SRNL investigate the impact of using boron rather than manganese as the poison. SRNL performed a series of experiments to help determine the disposal pathway of the material currently located in Tank 804. The objectives of this work are: (1) Determine the mobility of Tank 804 sludge when mixed with 10-15 parts sodium hydroxide as a function of pH between 10 and 14. (2) Determine the solubility of boron in sodium hydroxide solution with a free hydroxide concentration between 1 x 10{sup -4} and 2.0 M. (3) Recommend a filter pore size for SDD such that the filtrate contains no visible solids. (4) Determine whether a precipitate forms when the filtrate pH is adjusted to 12, 7, or 2 with nitric acid.

  11. Air-bubbling, hollow-fiber reactor with cell bleeding and cross-flow filtration.

    Science.gov (United States)

    Nishii, K; Sode, K; Karube, I

    1990-05-01

    Continuous asymmetric reduction of dyhydrooxoisophorone (DOIP) to 4-hydroxy-2,2,6-trimethylcyclo-hexanone (4-HTMCH) was achieved by a thermophilic bacterium Bacillus stearothermophilus NK86-0151. Three reactors were used: an air-bubbling hollow-fiber reactor with cell bleeding and cross-flow filtration, an air-lift reactor, and a CSTR with PAA immobilized cells. The maximum cell concentration of 11.1 g dry wt L(-1) was obtained in an air-bubbling hollow-fiber reactor, while in the other reactors the cell densities were between 3.5 and 4.1 g dry wt L(-1) The optimum bleed ratio was 0.1 at the dilution rate 0.3 h(-1) in the hollow-fiber reactor. The highest viable cell concentration was maintained in the dilution range of 0.4-0.7 h(-1) by a combination of proper cell bleeding and cross-flow filtration. The maximum volumetric productivity of 4-HTMCH reached 826 mg L(-1) h(-1) at the dilution rate 0.54 h(-1). This value was 4 and 2 times higher than those in the air-lift reactor and CSTR, respectively. The increasing viable cell concentration increased the volumetric productivity of 4-HTMCH. A cell free product solution was continuously obtained by cross-flow filtration.

  12. MODEL REPRESENTATION OF THE SPRAY DRYING PROCESS OF THE DISTILLERY STILLAGE FILTRATE BASED ON NAVIERSTOKES EQUATIONS

    Directory of Open Access Journals (Sweden)

    A. A. Shevtsov

    2015-01-01

    Full Text Available Spray drying of solutions and suspensions is among the most common methods of producing a wide range of powdered products in chemical, food and pharmaceutical industries. For the drying of heat-sensitive materials, which is fully applicable to the distillery stillage filtrate continuous-flow type of contact of drying agent and the solution droplets is examined. Two-phase simulation method of computational hydrodynamics in a stationary state for studying the process of drying of the distillery stillage filtrate in the pilot spray dryer under the following assumptions was used. The components form an ideal mixture, the properties of which are calculated directly from the properties of the components and their proportions. The droplets were presented in spherical form. The density and specific heat of the solution and the coefficient of vapors diffusion in the gas phase remained unchanged. To solve the heat exchange equations between the drying agent and the drops by the finite volume method the software package ANSYS CFX was used. The bind between the two phases was established by Navier-Stokes equations. The continuous phase (droplets of the distillery stillage filtrate was described by the k-ε turbulence model. The results obtained showed that the interaction of "drop-wall" causes a significant change of velocity, temperature and humidity both of a drying agent and the product particles. The behavior of the particles by spraying, collision with walls and deposition of the finished product allowed to determine the dependence of physical parameters of the drying process, of the geometric dimensions of the dryer. Comparison of simulation results with experimental data showed satisfactory convergence of the results: for the temperature of the powder 10% its humidity of 12% and temperature of the spent drying agent at the outlet from the drier of 13%. The possibility of using the model in the spray dryers designing, and control of the drying process

  13. Fast Filtration of Bacterial or Mammalian Suspension Cell Cultures for Optimal Metabolomics Results.

    Directory of Open Access Journals (Sweden)

    Natalie Bordag

    Full Text Available The metabolome offers real time detection of the adaptive, multi-parametric response of the organisms to environmental changes, pathophysiological stimuli or genetic modifications and thus rationalizes the optimization of cell cultures in bioprocessing. In bioprocessing the measurement of physiological intracellular metabolite levels is imperative for successful applications. However, a sampling method applicable to all cell types with little to no validation effort which simultaneously offers high recovery rates, high metabolite coverage and sufficient removal of extracellular contaminations is still missing. Here, quenching, centrifugation and fast filtration were compared and fast filtration in combination with a stabilizing washing solution was identified as the most promising sampling method. Different influencing factors such as filter type, vacuum pressure, washing solutions were comprehensively tested. The improved fast filtration method (MxP® FastQuench followed by routine lipid/polar extraction delivers a broad metabolite coverage and recovery reflecting well physiological intracellular metabolite levels for different cell types, such as bacteria (Escherichia coli as well as mammalian cells chinese hamster ovary (CHO and mouse myeloma cells (NS0.The proposed MxP® FastQuench allows sampling, i.e. separation of cells from medium with washing and quenching, in less than 30 seconds and is robustly designed to be applicable to all cell types. The washing solution contains the carbon source respectively the 13C-labeled carbon source to avoid nutritional stress during sampling. This method is also compatible with automation which would further reduce sampling times and the variability of metabolite profiling data.

  14. Water quality and treatment of river bank filtrate

    NARCIS (Netherlands)

    De Vet, W.W.J.M.; Van Genuchten, C.C.A.; Van Loosdrecht, M.C.M.; Van Dijk, J.C.

    2009-01-01

    In drinking water production, river bank filtration has the advantages of dampening peak concentrations of many dissolved components, substantially removing many micropollutants and removing, virtually completely, the pathogens and suspended solids. The production aquifer is not only fed by the

  15. Water quality and treatment of river bank filtrate

    NARCIS (Netherlands)

    De Vet, W.W.J.M.; Van Genuchten, C.C.A.; Van Loosdrecht, M.C.M.; Van Dijk, J.C.

    2010-01-01

    In drinking water production, river bank filtration has the advantages of dampening peak concentrations of many dissolved components, substantially removing many micropollutants and removing, virtually completely, the pathogens and suspended solids. The production aquifer is not only fed by the

  16. Granular bed filtration of high temperature biomass gasification gas.

    Science.gov (United States)

    Stanghelle, Daniel; Slungaard, Torbjørn; Sønju, Otto K

    2007-06-18

    High temperature cleaning of producer gas from biomass gasification has been investigated with a granular filter. Field tests were performed for several hours on a single filter element at about 550 degrees C. The results show cake filtration on the granular material and indicate good filtration of the biomass gasification producer gas. The relatively low pressure drop over the filter during filtration is comparable to those of bag filters. The granular filter can operate with high filtration velocities compared to bag filters and maintain high efficiency and a low residual pressure. This work is a part of the BioSOFC-up project that has a goal of utilizing the producer gas from the gasification plant in a solid oxide fuel cell (SOFC). The BioSOFC-up project will continue to the end of 2007.

  17. Effect of lithium therapy on glomerular filtration rate.

    Science.gov (United States)

    Decina, P; Oliver, J A; Sciacca, R R; Colt, E; Fieve, R R

    1983-08-01

    Patients taking lithium had a slightly higher serum creatinine concentration than controls. Creatinine concentration was independent of lithium level or therapy length, suggesting that lithium decreases glomerular filtration but that this effect is small, noncumulative, and of marginal clinical significance.

  18. Performance of multistage filtration using different filter media ...

    African Journals Online (AJOL)

    Performance of multistage filtration using different filter media against conventional water treatment systems. ... horizontal flow roughing filter (HRF)) as an alternative water treatment technology to the conventional one. A pilot- ... Article Metrics.

  19. Scaling and particulate fouling in membrane filtration systems

    NARCIS (Netherlands)

    Boerlage, S.F.E.

    2001-01-01

    Membrane filtration technologies have emerged as cost competitive and viable techniques in drinking and industrial water production. Despite advancements in membrane manufacturing and technology, membrane scaling and fouling remain major problems and may limit future growth in the industry. Scaling

  20. Advanced treatment of WWTP effluent with filtration leading to a pretreatment technique for membrane filtration.

    Science.gov (United States)

    Scherrenberg, S M; te Kloeze, A M; Janssen, A N; van Nieuwenhuijzen, A F; Menkveld, H W H; Bechger, M; van der Graaf, J H J M

    2010-01-01

    In 2000 the European Union introduced the Water Framework Directive (WFD). The aim of the WFD is having an ecological and chemical balance for all surface waters in Europe in 2015. The European Commission identified 33 priority substances and their maximum allowable concentrations, FHI-values (Fraunhofer Institute), which are specified in the Annex of the WFD. The objective of this research is to achieve the removal of suspended solids, nitrogen and total phosphorus together with priority substances. All these substances will be removed in one filter called a "One Step Total Effluent Polishing filter" i.e. 1-STEP(®) filter. For this purpose a filter pilot plant was tested at the WWTP Horstermeer. The results show that the filter can fulfil the target values in the filtrate water for total nitrogen (2.2 mg Ntotal/L) and total phosphorus (0.15 mg Ptotal/L). The majority of the priority (hazardous) substances in the WWTP effluent are already below the detection limit. Due to the low concentration ranges, the results on the removal of medicine and pesticides are only indicative. A decreasing tendency in the removal efficiency is shown for all measured compounds. The average specific ultrafiltration resistance (SUR) value decrease of the filter is 55% and the final value is always below 5·10(12) m(-2). This indicates that the filtrate water of the filter is very well filterable and can be used as ultrafiltration feedwater.

  1. Task 9 - centrifugal membrane filtration. Semi-annual report April 1--September 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Stepan, D.J.; Moe, T.A.; Collings, M.E.

    1997-05-01

    This report assesses a centrifugal membrane filtration technology developed by SpinTek Membrane Systems, Inc. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. The Tank Waste Focus Area was chosen for study. Membrane-screening tests were performed with the STC-X4 static test cell filtration unit, using five ceramic membranes with different pore size and composition. Based on permeate flux, a 0.25-{mu}m TiO{sub 2}/Al{sub 2}O{sub 3} membrane was selected for detailed performance evaluation using the centrifugal membrane filtration unit with a surrogate tank waste solution. The performance of the unit was evaluated with a statistical test design that determined the effect of temperature, pressure, membrane rotational speed, and solids loading on permeate flux. All four variables were found to be statistically significant, with the magnitude of the effect in the order of temperature, solids loading, rotor speed, and pressure. Temperature, rotor speed, and pressure had an increasing effect on flux with increasing value, while increases in solids loading showed a decrease in permeate flux. Significant interactions between rotor speed and solids loading and pressure and solids loading were also observed. The regression equation derived from test data had a correlation coefficient of 0.934, which represents a useful predictive capability for integrating the technology into DOE cleanup efforts. An extended test run performed on surrogate waste showed some deterioration in filtration performance, based on flux, apparently due to the buildup of solids near the inner portion of the membrane where relative membrane velocities were low. Continued testing of the system will focus on modifications to the shear pattern across the entire membrane surface to affect improved long-term performance.

  2. Effect of Nanofibers on Spore Penetration and Lunar Dust Filtration

    OpenAIRE

    Phil Gibson, Ph.D.; Heidi Schreuder-Gibson, Ph.D.; Robert Stote; Margaret Roylance, Ph.D.; Cathy Capone; Masami Nakagawa, Ph.D.

    2008-01-01

    The results of two separate studies on biological spore penetration and simulated lunar dust filtration illustrate the use of nanofibers in some nonstandard filtration applications (nanofibers are generally defined as having diameters of less than a micron). In the first study, a variety of microporous liners containing microfibers and nanofibers were combined with cotton-based fabrics in order to filter aerosolized spores. The aerosol penetration resistance of the nanofiber-lined fabrics was...

  3. Water Clarity Simulant for K East Basin Filtration Testing

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Andrew J.

    2006-01-20

    This document provides a simulant formulation intended to mimic the behavior of the suspended solids in the K East (KE) Basin fuel storage pool. The simulant will be used to evaluate alternative filtration apparatus to improve Basin water clarity and to possibly replace the existing sandfilter. The simulant was formulated based on the simulant objectives, the key identified parameters important to filtration, the composition and character of the KE Basin suspended sludge particles, and consideration of properties of surrogate materials.

  4. Pesticide removal by combined ozonation and granular activated carbon filtration

    OpenAIRE

    Orlandini, E.

    1999-01-01

    Since the seventies, new water treatment processes have been introduced in the production of drinking water from surface water. Their major aim was to adequately cope with the disinfection of this water, and/or with the removal of pesticides and other organic micropollutants from it. This research focused on Biological Activated Carbon (BAC) filtration, which is a combination of ozonation and GAC filtration. Its general goal was identification and understanding of the mechanisms that underlie...

  5. Sampling Rate Independent Filtration Approach for Automatic ECG Delineation

    CERN Document Server

    Chereda, Hryhorii; Tymoshenko, Yury

    2016-01-01

    In this paper different types of ECG automatic delineation approaches were overviewed. A combination of these approaches was used to create sampling rate independent filtration algorithm for automatic ECG delineation that is capable of distinguishing different morphologies of T and P waves and QRS complexes. Created filtration algorithm was compared with algorithme \\`a trous. It was investigated that continuous wavelets transform with proposed automatic adaptation for different sampling rates procedure can be used for delineation problem.

  6. Purification of inkjet ink from water using liquid phase, electric discharge polymerization and cellulosic membrane filtration.

    Science.gov (United States)

    Jordan, Alexander T; Hsieh, Jeffery S; Lee, Daniel T

    2013-01-01

    A method to separate inkjet ink from water was developed using a liquid phase, electric discharge process. The liquid phase, electric discharge process with filtration or sedimentation was shown to remove 97% of inkjet ink from solutions containing between 0.1-0.8 g/L and was consistent over a range of treatment conditions. Additionally, particle size analysis of treated allyl alcohol and treated propanol confirmed the electric discharge treatment has a polymerization mechanism, and small molecule analysis of treated methanol using gas chromatography and mass spectroscopy confirmed the mechanism was free radical initiated polymerization.

  7. Removal of arsenic from contaminated groundwater with application of iron electrodissolution, aeration and sand filtration

    DEFF Research Database (Denmark)

    Kowalski, Krysztof; Arturi, Kasia; Søgaard, Erik Gydesen

    2014-01-01

    The results from a new water treatment system for arsenic removal are presented. The technology is based on the employment of an electrolytic iron dissolution and efficient aeration procedure prior to sand filtration. The treatment was introduced and investigated in a pilot scale plant and full...... scale waterworks. The pilot scale results showed a possibility for an efficient arsenic removal from spiked solutions (with As in the range of 50–85 μg/L) depending on the process conditions (flow and applied current). In the waterworks where the system was implemented for a period of 14 months...

  8. Characterization and modification of particulate properties to enhance filtration performance

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, T.R.; Vann Bush, P.; Robinson, M.S.

    1990-06-01

    The specific objectives of this project are to characterize the particulate properties that determine the filtration performance of fabric filters, and to investigate methods for modifying these particulate properties to enhance filtration performance. Inherent in these objectives is the development of an experimental approach that will lead to full-scale implementation of beneficial conditioning processes identified during the project. The general approach has included a large number of laboratory evaluations to be followed by optional field tests of a new successful conditioning processes performed on a sidestream device. This project was divided into five tasks. The schedule followed for these tasks is shown in Figure 4. Tasks 2 and 3 each focus on one of the two complementary parts of the project. Task 2 Parametric Tests of Ashes and Fabrics, evaluates the degree to which ash properties and fabric design determine filtration performance. Task 3 Survey of Methods to Modify the Particle Filtration Properties, provides a literature review and laboratory study of techniques to modify ash properties. The results of these two tasks were used in Task 4 Proof-of-Concept Tests of Methods to Modify Particle Filtration Properties to demonstrate the effects on filtration performance of modifying ash properties. The findings of all the tasks are summarized in this Final Report. 13 refs.

  9. Wind Turbine Gearbox Oil Filtration and Condition Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Shuangwen

    2015-10-25

    This is an invited presentation for a pre-conference workshop, titled advances and opportunities in lubrication: wind turbine, at the 2015 Society of Tribologists and Lubrication Engineers (STLE) Tribology Frontiers Conference held in Denver, CO. It gives a brief overview of wind turbine gearbox oil filtration and condition monitoring by highlighting typical industry practices and challenges. The presentation starts with an introduction by covering recent growth of global wind industry, reliability challenges, benefits of oil filtration and condition monitoring, and financial incentives to conduct wind operation and maintenance research, which includes gearbox oil filtration and condition monitoring work presented herein. Then, the presentation moves on to oil filtration by stressing the benefits of filtration, discussing typical main- and offline-loop practices, highlighting important factors considered when specifying a filtration system, and illustrating real-world application challenges through a cold-start example. In the next section on oil condition monitoring, a discussion on oil sample analysis, oil debris monitoring, oil cleanliness measurements and filter analysis is given based on testing results mostly obtained by and at NREL, and by pointing out a few challenges with oil sample analysis. The presentation concludes with a brief touch on future research and development (R and D) opportunities. It is hoping that the information presented can inform the STLE community to start or redirect their R and D work to help the wind industry advance.

  10. C*-Algebras over Topological Spaces: Filtrated K-Theory

    CERN Document Server

    Meyer, Ralf

    2008-01-01

    We define the filtrated K-theory of a C*-algebra over a finite topological space X and explain how to construct a spectral sequence that computes the bivariant Kasparov theory over X in terms of filtrated K-theory. For finite spaces with totally ordered lattice of open subsets, this spectral sequence becomes an exact sequence as in the Universal Coefficient Theorem, with the same consequences for classification. We also exhibit an example where filtrated K-theory is not yet a complete invariant. We describe a space with four points and two C*-algebras over this space in the bootstrap class that have isomorphic filtrated K-theory but are not KK(X)-equivalent. For this particular space, we enrich filtrated K-theory by another K-theory functor, so that there is again a Universal Coefficient Theorem. Thus the enriched filtrated K-theory is a complete invariant for purely infinite, stable C*-algebras with this particular spectrum and belonging to the appropriate bootstrap class.

  11. PREPARATION MICRO-FILTRATION CERAMIC MEMBRANE FROM NATURAL ZEOLITE FOR PROCION RED MX8B AND METHYLENE BLUE FILTRATION

    Directory of Open Access Journals (Sweden)

    Dyah Choiriyah

    2015-12-01

    Full Text Available The study of ceramic membrane fabrication from natural zeolite and its utilization for filtration of procion red MX8B and methylene blue has been investigated. The purposes of this study are to determine the effect of pressure on membrane permeability and selectivity and utilize natural zeolite as ceramic membranes procion red MX8B and methylene blue filtration. The membrane was prepared by metide press pellets and then calcined at 850 oC. The membranes were characterized by mechanical test, flux and rejection of dye. The compression test of the membrane found the values of 1369.178 psi in dry conditions to 1388.933 psi in wet conditions. The flux test found that the higher the pressure applied, the flux was increase. However, the high pressure also decreased the selectivity. Rejection test found that the rejection of methylene blue filtration up to 70 %. Meanwhile, procion red MX8B filtration has rejectivity less than 20 %.

  12. Harvesting of Dunaliella tertiolecta cells by magnetic filtration

    Science.gov (United States)

    Manousakis, Emmanouil; Manariotis, Ioannis D.

    2015-04-01

    The rising cost and reduced reserves of fossil fuels have enhanced the interest for finding alterative energy sources. Microalgae are considered to be the only sustainable option in biodiesel production for two key points. The energy yield from microalgae is much higher than that of oil producing crops, and the cultivation of algae it is not antagonistic with food supply chain. Because of the small size of microalgae and the dilute nature of algal cultures, the harvesting cost of microalgae is so far a limiting step for the scale up of microalgal biofuel production. It is estimated that the algal harvesting cost is at least 20-30% of the total biomass production cost. Traditional methods, which have been employed for the recovery of microalgal biomass, include centrifugation, gravity separation, filtration, flocculation, and flotation. Alternative approaches, other than conventional methods, capable of processing large cultures volume at a low cost, and reducing effluent toxicity are essential for microalgal biomass production. Magnetic separation is a promising technology and has been applied for algal removal in the mid of 1970s. The aim of this study was to investigate the harvesting of microalgae cells using magnetic microparticles (MPs). Dunaliella tertiolecta was selected as a representative for marine microalgae. The cultivation of microalgae was conducted under continuous artificial light, in 20 L flasks. Iron oxide microparticles were prepared by microwave irradiation of FeSO4 7H2O in an alkaline solution. Samples were taken at different operation intervals to conduct harvesting studies. Batch and flow-through experiments were conducted in order to investigate the effect of the magnetic material on microalgae removal. Algal removal in flow through experiments ranged from 70 to 85% depending on the initial MPs concentration even at very short hydraulic retention times (i.e. 2 min). In batch tests, algal removal was up to 97% at MPs concentration of 490 mg/L.

  13. Riverbank filtration for the treatment of highly turbid Colombian rivers

    Science.gov (United States)

    Gutiérrez, Juan Pablo; van Halem, Doris; Rietveld, Luuk

    2017-05-01

    The poor quality of many Colombian surface waters forces us to seek alternative, sustainable treatment solutions with the ability to manage peak pollution events and to guarantee the uninterrupted provision of safe drinking water to the population. This review assesses the potential of using riverbank filtration (RBF) for the highly turbid and contaminated waters in Colombia, emphasizing water quality improvement and the influence of clogging by suspended solids. The suspended sediments may be favorable for the improvement of the water quality, but they may also reduce the production yield capacity. The cake layer must be balanced by scouring in order for an RBF system to be sustainable. The infiltration rate must remain high enough throughout the river-aquifer interface to provide the water quantity needed, and the residence time of the contaminants must be sufficient to ensure adequate water quality. In general, RBF seems to be a technology appropriate for use in highly turbid and contaminated surface rivers in Colombia, where improvements are expected due to the removal of turbidity, pathogens and to a lesser extent inorganics, organic matter and micro-pollutants. RBF has the potential to mitigate shock loads, thus leading to the prevention of shutdowns of surface water treatment plants. In addition, RBF, as an alternative pretreatment step, may provide an important reduction in chemical consumption, considerably simplifying the operation of the existing treatment processes. However, clogging and self-cleansing issues must be studied deeper in the context of these highly turbid waters to evaluate the potential loss of abstraction capacity yield as well as the development of different redox zones for efficient contaminant removal.

  14. Four years experience with filtration systems in commercial nurseries for eliminating Phytophthora species from recirculation water

    Science.gov (United States)

    T. Ufer; M. Posner; H.-P. Wessels; S. Wagner; K. Kaminski; T. Brand; Werres S.

    2008-01-01

    In a four year project, three different filtration systems were tested under commercial nursery conditions to eliminate Phytophthora spp. from irrigation water. Five nurseries were involved in the project. Slow sand filtration systems were tested in three nurseries. In the fourth nursery, a filtration system with lava grains (Shieer® Bio filtration)...

  15. A comparison of facemask and respirator filtration test methods.

    Science.gov (United States)

    Rengasamy, Samy; Shaffer, Ronald; Williams, Brandon; Smit, Sarah

    2017-02-01

    NIOSH published a Federal Register Notice to explore the possibility of incorporating FDA required filtration tests for surgical masks (SMs) in the 42 CFR Part 84 respirator certification process. There have been no published studies comparing the filtration efficiency test methods used for NIOSH certification of N95 filtering facepiece respirators (N95 FFRs) with those used by the FDA for clearance of SMs. To address this issue, filtration efficiencies of "N95 FFRs" including six N95 FFR models and three surgical N95 FFR models, and three SM models were measured using the NIOSH NaCl aerosol test method, and FDA required particulate filtration efficiency (PFE) and bacterial filtration efficiency (BFE) methods, and viral filtration efficiency (VFE) method. Five samples of each model were tested using each method. Both PFE and BFE tests were done using unneutralized particles as per FDA guidance document. PFE was measured using 0.1 µm size polystyrene latex particles and BFE with ∼3.0 µm size particles containing Staphylococcus aureus bacteria. VFE was obtained using ∼3.0 µm size particles containing phiX 174 as the challenge virus and Escherichia coli as the host. Results showed that the efficiencies measured by the NIOSH NaCl method for "N95 FFRs" were from 98.15-99.68% compared to 99.74-99.99% for PFE, 99.62-99.9% for BFE, and 99.8-99.9% for VFE methods. Efficiencies by the NIOSH NaCl method were significantly (p = PFE, BFE, and VFE methods produced no significant difference. The above results show that the NIOSH NaCl method is relatively conservative and is able to identify poorly performing filtration devices. The higher efficiencies obtained using PFE, BFE and VFE methods show that adding these supplemental particle penetration methods will not improve respirator certification.

  16. Determination of neutron resonance parameters of Neptunium 237 between 0 and 500 eV. The covariance matrices of statistical and of systematic origin, relating the resonance parameters, are also given; Determination des parametres des resonances neutroniques du neptunium 237, en dessous de 500eV, et obtention des matrices de covariances statistiques et systematiques entre les parametres de ces resonances

    Energy Technology Data Exchange (ETDEWEB)

    Lepretre, A.; Herault, N. [CEA Saclay, Dept. d' Astrophysique de Physique des Particules, de Physique Nucleaire et de l' Instrumentation Associee, 91- Gif sur Yvette (France); Brusegan, A.; Noguere, G.; Siegler, P. [Institut des Materiaux et des Metrologies - IRMM, Joint Research Centre, Gell (Belgium)

    2002-12-01

    This report is a follow up of the report CEA DAPNIA/SPHN-99-04T of Vincent Gressier. In the frame of a collaboration between the 'Commissariat a l'Energie Atomique (CEA)' and the Institute for Reference Materials and Measurement (IRMM, Geel, Belgique), the resonance parameters of neptunium 237 have been determined in the energy interval between 0 and 500 eV. These parameters have been obtained by using the Refit code in analysing simultaneously three transmission experiments. The covariance matrix of statistical origin is provided. A new method, based on various sensitivity studies is proposed for determining also the covariance matrix of systematic origin, relating the resonance parameters. From an experimental viewpoint, the study indicated that, with a large probability, the background spectrum has structure. A two dimensional profiler for the neutron density has been proved feasible. Such a profiler could, among others, demonstrate the existence of the structured background. (authors)

  17. Mathematical modeling of gas-condensate mixture filtration in porous media taking into account non-equilibrium of phase transitions

    Science.gov (United States)

    Kachalov, V. V.; Molchanov, D. A.; Sokotushchenko, V. N.; Zaichenko, V. M.

    2016-11-01

    At the present time, a considerable part of the largest dry gas reservoirs in Russia are found in the stage of declining production, therefore active exploitation of gas-condensate fields will begin in the coming decades. There is a significant discrepancy between the project and the actual value of condensate recovery factor while producing reservoir of this type, which is caused by insufficient knowledge about non-equilibrium filtration mechanisms of gas-condensate mixtures in reservoir conditions. A system of differential equations to describe filtration process of two-phase multicomponent mixture for one-, two- and three-dimensional cases is presented in this work. The solution of the described system was made by finite-element method in the software package FlexPDE. Comparative distributions of velocities, pressures, saturations and phase compositions of three-component mixture along the reservoir model and in time in both cases of equilibrium and non-equilibrium filtration processes were obtained. Calculation results have shown that system deviation from the thermodynamic equilibrium increases gas phase flow rate and reduces liquid phase flow rate during filtration process of gas-condensate mixture.

  18. Application of acoustic agglomeration to enhance air filtration efficiency in air-conditioning and mechanical ventilation (ACMV) systems.

    Science.gov (United States)

    Ng, Bing Feng; Xiong, Jin Wen; Wan, Man Pun

    2017-01-01

    The recent episodes of haze in Southeast Asia have caused some of the worst regional atmospheric pollution ever recorded in history. In order to control the levels of airborne fine particulate matters (PM) indoors, filtration systems providing high PM capturing efficiency are often sought, which inadvertently also results in high airflow resistance (or pressure drop) that increases the energy consumption for air distribution. A pre-conditioning mechanism promoting the formation of particle clusters to enhance PM capturing efficiency without adding flow resistance in the air distribution ductwork could provide an energy-efficient solution. This pre-conditioning mechanism can be fulfilled by acoustic agglomeration, which is a phenomenon that promotes the coagulation of suspended particles by acoustic waves propagating in the fluid medium. This paper discusses the basic mechanisms of acoustic agglomeration along with influencing factors that could affect the agglomeration efficiency. The feasibility to apply acoustic agglomeration to improve filtration in air-conditioning and mechanical ventilation (ACMV) systems is investigated experimentally in a small-scale wind tunnel. Experimental results indicate that this novel application of acoustic pre-conditioning improves the PM2.5 filtration efficiency of the test filters by up to 10% without introducing additional pressure drop. The fan energy savings from not having to switch to a high capturing efficiency filter largely outstrip the additional energy consumed by the acoustics system. This, as a whole, demonstrates potential energy savings from the combined acoustic-enhanced filtration system without compromising on PM capturing efficiency.

  19. Selection of optimized air pollutant filtration technologies for petrochemical industries through multiple-attribute decision-making.

    Science.gov (United States)

    Moridi, Parvin; Atabi, Farideh; Nouri, Jafar; Yarahmadi, Rasoul

    2017-07-15

    Selecting cost-effective and efficient air filtration technologies that ensure sustainable development is a challenge to national, regional and local policy makers. Various factors such as efficiency, maintainability, and design of the developed devices can affect the selection of optimized technologies. The present study aimed to select optimal technologies for air filtration devices in petrochemical industries through a multi-criteria decision-making (MADM) method based on a fuzzy model of Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). Five criteria (filtration efficiency, cost, maintainability, designability, and size) were used to rank air pollution control technologies designed to eliminate particulate matter (PM), volatile organic compounds (VOCs), and ammonia (NH3). According to the results, the research criteria had different weights for different air pollutants. High-efficiency particulate air (HEPA + pre collector) filters, plasma chemistry, and chemical absorption were identified as the most appropriate filtration methods for PM, VOCs, and NH3, respectively (coefficients = 0.923, 0.9586, and 0.867, respectively). Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Silver nanoparticle-doped zirconia capillaries for enhanced bacterial filtration.

    Science.gov (United States)

    Wehling, Julia; Köser, Jan; Lindner, Patrick; Lüder, Christian; Beutel, Sascha; Kroll, Stephen; Rezwan, Kurosch

    2015-03-01

    Membrane clogging and biofilm formation are the most serious problems during water filtration. Silver nanoparticle (Agnano) coatings on filtration membranes can prevent bacterial adhesion and the initiation of biofilm formation. In this study, Agnano are immobilized via direct reduction on porous zirconia capillary membranes to generate a nanocomposite material combining the advantages of ceramics being chemically, thermally and mechanically stable with nanosilver, an efficient broadband bactericide for water decontamination. The filtration of bacterial suspensions of the fecal contaminant Escherichia coli reveals highly efficient bacterial retention capacities of the capillaries of 8 log reduction values, fulfilling the requirements on safe drinking water according to the U.S. Environmental Protection Agency. Maximum bacterial loading capacities of the capillary membranes are determined to be 3×10(9)bacterialcells/750mm(2) capillary surface until back flushing is recommendable. The immobilized Agnano remain accessible and exhibit strong bactericidal properties by killing retained bacteria up to maximum bacterial loads of 6×10(8)bacterialcells/750mm(2) capillary surface and the regenerated membranes regain filtration efficiencies of 95-100%. Silver release is moderate as only 0.8% of the initial silver loading is leached during a three-day filtration experiment leading to average silver contaminant levels of 100μg/L.

  1. Spontaneous water filtration of bio-inspired membrane

    Science.gov (United States)

    Kim, Kiwoong; Kim, Hyejeong; Lee, Sang Joon

    2016-11-01

    Water is one of the most important elements for plants, because it is essential for various metabolic activities. Thus, water management systems of vascular plants, such as water collection and water filtration have been optimized through a long history. In this view point, bio-inspired technologies can be developed by mimicking the nature's strategies for the survival of the fittest. However, most of the underlying biophysical features of the optimized water management systems remain unsolved In this study, the biophysical characteristics of water filtration phenomena in the roots of mangrove are experimentally investigated. To understand water-filtration features of the mangrove, the morphological structures of its roots are analyzed. The electrokinetic properties of the root surface are also examined. Based on the quantitatively analyzed information, filtration of sodium ions in the roots are visualized. Motivated by this mechanism, spontaneous desalination mechanism in the root of mangrove is proposed by combining the electrokinetics and hydrodynamic transportation of ions. This study would be helpful for understanding the water-filtration mechanism of the roots of mangrove and developing a new bio-inspired desalination technology. This research was financially supported by the National Research Foundation (NRF) of Korea (Contract Grant Number: 2008-0061991).

  2. Impact of Acidification on Pollutants Fate and Soil Filtration Function

    Directory of Open Access Journals (Sweden)

    Jarmila Makovniková

    2014-12-01

    Full Text Available The objective of this paper was to investigate the effects of simulated acid load on the fate of inorganic pollutants (Cd, Pb, soil sorption potential, soil filtration func-tion. We made use of a short-term acidification pot experiment with grown plant of spring barley cultivated at 4 different soil types (Fluvisol, Cambisol, Stagnosol, Podzol. The potential of soil filtration was evaluated according to the Eq.: [Soil filtration function]=[Potential of soil sorbents]+[Potential of total content of inor-ganic pollutants]. Potential of soil sorbents (PSS is defined by qualitative (pH, or-ganic matter quality - A400/600 and quantitative factors (carbon content-Cox, humus layer thickness-H according to the Eq.:[PSS]=F(pH+F(A465/665+F(Cox*F(H. Acid load significantly influenced soil sorption potential and thus affected increase in Cd and Pb mobility what was reflected in their transfer into the plants. Results of soil filtration function showed significant change of filtration function in Cambisol.

  3. Water quality and treatment of river bank filtrate

    Directory of Open Access Journals (Sweden)

    W. W. J. M. de Vet

    2010-06-01

    Full Text Available In drinking water production, river bank filtration has the advantages of dampening peak concentrations of many dissolved components, substantially removing many micropollutants and removing, virtually completely, the pathogens and suspended solids. The production aquifer is not only fed by the river bank infiltrate but also by water percolating through covering layers. In the polder areas, these top layers consist of peat and deposits from river sediments and sea intrusions.

    This paper discusses the origin and fate of macro components in river bank filtrate, based on extensive full-scale measurements in well fields and treatment systems of the Drinking Water Company Oasen in the Netherlands. First, it clarifies and illustrates redox reactions and the mixing of river bank filtrate and PW as the dominant processes determining the raw water quality for drinking water production. Next, full-scale results are elaborated on to evaluate trickling filtration as an efficient and proven one-step process to remove methane, iron, ammonium and manganese. The interaction of methane and manganese removal with nitrification in these systems is further analyzed. Methane is mostly stripped during trickling filtration and its removal hardly interferes with nitrification. Under specific conditions, microbial manganese removal may play a dominant role.

  4. Enhancement of fine particle filtration with efficient humidification☆

    Institute of Scientific and Technical Information of China (English)

    Yumei Zhang; Weidong Zhang; Zhengyu Yang; Junteng Liu; Fushen Yang; Ning Li; Le Du⁎

    2016-01-01

    Filtration is one of the most effective methods to remove suspended fine particles from air. In filtration processes, pressure drop of compact dust cake causes problems in efficiency and economy, which has received increasing at-tention and stil remains chal enging. In this study, we developed a novel technique to intensify the filtration of fine particles with efficient humidification. Two strategies for humidification, including ultrasonic atomization and steam humidification (control ing of ambient humidity), were employed and proved to be both effective. The re-generation frequency of the filter could be reduced by 55%with ultrasonic atomization, while steam humidification could lead to a 78%reduction in regeneration frequency. The effect of operating conditions on pressure drop and the mass loading during filtration were investigated. The dust cake showed a loose and porous structure with an opti-mized droplet-to-particle ratio. With the ratio of 1.53 and 0.0282, the maximum mass loading was 552 g·m−2 upon the ultrasonic atomization and 720 g·m−2 upon the steam humidification. The results show that humidification could slow down the increase of pressure drop during filtration and improve the efficiency of process.

  5. Effect of membrane filtration artifacts on dissolved trace element concentrations

    Science.gov (United States)

    Horowitz, Arthur J.; Elrick, Kent A.; Colberg, Mark R.

    1992-01-01

    Among environment scientists, the current and almost universally accepted definition of dissolved constituents is an operational one; only those materials which pass through a 0.45-??m membrane filter are considered to be dissolved. Detailed laboratory and field studies on Fe and Al indicate that a number of factors associated with filtration, other than just pore size, can substantially alter 'dissolved' trace element concentrations; these include: filter type, filter diameter, filtration method, volume of sample processed, suspended sediment concentration, suspended sediment grain-size distribution, concentration of colloids and colloidally associated trace elements and concentration of organic matter. As such, reported filtered-water concentrations employing the same pore size filter may not be equal. Filtration artifacts may lead to the production of chemical data that indicate seasonal or annual 'dissolved' chemical trends which do not reflect actual environmental conditions. Further, the development of worldwide averages for various dissolved chemical constituents, the quantification of geochemical cycles, and the determination of short- or long-term environmental chemical trends may be subject to substantial errors, due to filtration artifacts, when data from the same or multiple sources are combined. Finally, filtration effects could have a substantial impact on various regulatory requirements.

  6. Transforming growth factor-beta and the glomerular filtration barrier

    Directory of Open Access Journals (Sweden)

    Ayesha Ghayur

    2013-03-01

    Full Text Available The increasing burden of chronic kidney disease worldwide and recent advancements in the understanding of pathologic events leading to kidney injury have opened up new potential avenues for therapies to further diminish progression of kidney disease by targeting the glomerular filtration barrier and reducing proteinuria. The glomerular filtration barrier is affected by many different metabolic and immune-mediated injuries. Glomerular endothelial cells, the glomerular basement membrane, and podocytes—the three components of the filtration barrier—work together to prevent the loss of protein and at the same time allow passage of water and smaller molecules. Damage to any of the components of the filtration barrier can initiate proteinuria and renal fibrosis. Transforming growth factor-beta (TGF-β is a pleiotropic cytokine strongly associated with the fibrogenic response. It has a known role in tubulointerstitial fibrosis. In this review we will highlight what is known about TGF-β and how it interacts with the components of glomerular filtration barrier and causes loss of function and proteinuria.

  7. Effect of Nanofibers on Spore Penetration and Lunar Dust Filtration

    Directory of Open Access Journals (Sweden)

    Phil Gibson, Ph.D.

    2008-06-01

    Full Text Available The results of two separate studies on biological spore penetration and simulated lunar dust filtration illustrate the use of nanofibers in some nonstandard filtration applications (nanofibers are generally defined as having diameters of less than a micron. In the first study, a variety of microporous liners containing microfibers and nanofibers were combined with cotton-based fabrics in order to filter aerosolized spores. The aerosol penetration resistance of the nanofiber-lined fabrics was measured, and some analysis was conducted of where the particles are captured within the fabric layers. Testing was conducted with aerosolized living spores, in order to evaluate the efficacy of various fabric treatments on spore viability within the fabric layers after exposure. Reported are the results of studies on fabrics with and without a removable electrospun nanofiber liner, and the fate of the spores within the fabric layers. In the second study, non-instrumented filtration testing using simulated lunar dust determined the comparative filtration efficiency of various nonwoven filtration media. Nanofiber witness media, combined with scanning electron microscope images, showed that an electrospun nonwoven filter layer effectively filtered out all the large and fine particles of the simulated lunar dust.

  8. Technology Review of Modern Gas Turbine Inlet Filtration Systems

    Directory of Open Access Journals (Sweden)

    Melissa Wilcox

    2012-01-01

    Full Text Available An inlet air filtration system is essential for the successful operation of a gas turbine. The filtration system protects the gas turbine from harmful debris in the ambient air, which can lead to issues such as FOD, erosion, fouling, and corrosion. These issues if not addressed will result in a shorter operational life and reduced performance of the gas turbine. Modern day filtration systems are comprised of multiple filtration stages. Each stage is selected based on the local operating environment and the performance goals for the gas turbine. Selection of these systems can be a challenging task. This paper provides a review of the considerations for selecting an inlet filtration system by covering (1 the characteristics of filters and filter systems, (2 a review of the many types of filters, (3 a detailed look at the different environments where the gas turbine can operate, (4 a process for evaluating the site where the gas turbine will be or is installed, and (5 a method to compare various filter system options with life cycle cost analysis.

  9. Oviposition Attractancy of Bacterial Culture Filtrates: response of Culex quinquefasciatus

    Directory of Open Access Journals (Sweden)

    S Poonam

    2002-04-01

    Full Text Available Oviposition attractants could be used for monitoring as well as controlling mosquitoes by attracting them to lay eggs at chosen sites. In the present study, culture filtrates of seven bacterial species were tested for their attractancy against gravid females of Culex quinquefasciatus. When their oviposition active indices (OAI were studied, the culture filtrates of Bacillus cereus and Pseudomonas fluorescens exhibited oviposition attractancy (OAI = >0.3 at 100 ppm and the OAI were respectively 0.70 and 0.47. Culture filtrates of B. thuringiensis var. israelensis (wild type, B. t. var. israelensis (mutant and B. sphaericus showed attractancy at 2000 ppm with OAI of respectively 0.71, 0.59 and 0.68. However, the OAI of B. megaterium as well as Azospirillum brasilense was 0.13 (at 2000 ppm, which was less than 0.3 required to be considered them as attractants. When the oviposition attractancy of the bacterial culture filtrates were compared with that of a known oviposition attractant, p-cresol (at 10 ppm, the culture filtrates of B. t. var. israelensis (wild type and B. cereus were found to be more active than p-cresol, respectively with 64.2 and 54.3% oviposition.

  10. Pharmacologic Atrial Natriuretic Peptide Reduces Human Leg Capillary Filtration

    Science.gov (United States)

    Watenpaugh, Donald E.; Vissing, Susanne F.; Lane, Lynda D.; Buckey, Jay C.; Firth, Brian G.; Erdman, William; Hargens, Alan R.; Blomqvist, C. Gunnar

    1995-01-01

    Atrial natriuretic peptide (ANP) is produced and secreted by atrial cells. We measured calf capillary filtration rate with prolonged venous-occlusion plethys-mography of supine health male subjects during pharmacologic infusion of ANP (48 pmol/kg/min for 15 min; n equals 6) and during placebo infusion (n equals 7). Results during infusions were compared to prior control measurements. ANP infusion increased plasma (ANP) from 30 plus or minus 4 to 2,568 plus or minus 595 pmol/L. Systemic hemoconcentration occurred during ANP infusion; mean hematocrit and plasma colloid osmotic pressure increased 4.6 and 11.3 percent respectively, relative to pre-infusion baseline values (p is less than 0.05). Mean calf filtration, however was significantly reduced from 0.15 to 0.08 ml/100 ml/min with ANP. Heart rate increased 20 percent with ANP infusion, wheras blood pressure was unchanged. Calf conductance (blood flow/arterial pressure) and venous compliance were unaffected by ANP infusion. Placebo infusion had no effect relative to prior baseline control measurements. Although ANP induced systemic capillary filtration, in the calf, filtration was reduced with ANP. Therefore, phamacologic ANP infusion enhances capillary filtration from the systemic circulation, perhaps at upper body or splanchic sites or both, while having the opposite effect in the leg.

  11. Robust utility maximization in a discontinuous filtration

    CERN Document Server

    Jeanblanc, Monique; Ngoupeyou, Armand

    2012-01-01

    We study a problem of utility maximization under model uncertainty with information including jumps. We prove first that the value process of the robust stochastic control problem is described by the solution of a quadratic-exponential backward stochastic differential equation with jumps. Then, we establish a dynamic maximum principle for the optimal control of the maximization problem. The characterization of the optimal model and the optimal control (consumption-investment) is given via a forward-backward system which generalizes the result of Duffie and Skiadas (1994) and El Karoui, Peng and Quenez (2001) in the case of maximization of recursive utilities including model with jumps.

  12. Silicon carbide-based membranes with high soot particle filtration efficiency, durability and catalytic activity for CO/HC oxidation and soot combustion

    NARCIS (Netherlands)

    Sandra, F.; Ballestero, A.; NGuyen, V. L.; Tsampas, M. N.; Vernoux, P.; Balan, C.; Iwamoto, Y.; Demirci, U. B.; Miele, P.; Bernard, S.

    2016-01-01

    We report here the solution coatings of Diesel Particulate Filter (DPF) with allylhydridopolycarbosilane (AHPCS)-based polymers leading to supported silicon carbide (SiC)-based membranes with high temperature soot particle filtration efficiency, durability and catalytic activity. In a first part of

  13. Filtration des fluides de forage à travers les parois du puits - Bibliographie Filtration of Drilling Fluids Through Borehole Walls

    Directory of Open Access Journals (Sweden)

    Martin M.

    2006-11-01

    Full Text Available Ce document résume un certain nombre de données déjà publiées, relatives à la filtration du fluide de forage, de l'annulaire vers les formations traversées, durant l'approfondissement du puits. On considère : - d'une part, les phénomènes de filtration : . le long des parois (filtration dynamique durant les périodes de circulation - filtration statique durant les arrêts, . sous l'outil ; - d'autre part, certaines de leurs conséquences, en particulier leur influence : . sur la vitesse d'avancement, . sur les risques de coincement de la garniture par pression différentielle, . sur l'envahissement des zones poreuses et perméables. Les phénomènes et leurs conséquences dépendent de très nombreux facteurs dont certains jouent des rôles d'importance très voisine. Leurs études nécessitent des moyens expérimentaux bien adaptés, permettant une simulation suffisamment rigoureuse des conditions de forage. Les résultats ne peuvent être généralisés et doivent être exprimés en fonction des paramètres opératoires choisis. This article reviews varions data which have already been published and which concern the filtration of drilling fluid from the annular space into the formations crossed through during the drilling of a borehole. The following aspects are considered: (i filtration phenomena along borehole walls (dynamic filtration during circulation, and static filtration during shutdowns and underneath the bit; (ii some of the consequences of this filtration, and especially its influence on the rate of penetration, on risks of drill string sticking as the result of differential pressure, and on the invasion of porous and permeable zones. Such phenomena and their consequences depend on a great many factor, some which play roles of quite similar importance. Resaerch on such phenomena requires well suited experimental facilities enabling the sufficiently cllose simulation of drilling conditions. the results of such research

  14. EX-PRESS Glaucoma Filtration Device: efficacy, safety, and predictability.

    Science.gov (United States)

    Chan, Jessica E; Netland, Peter A

    2015-01-01

    Trabeculectomy has been the traditional primary surgical therapy for open-angle glaucoma. While trabeculectomy is effective in lowering intraocular pressure, complications associated with the procedure have motivated the development of alternative techniques and devices, including the EX-PRESS Glaucoma Filtration Device. This review describes the efficacy, safety, complication rates, and potential advantages and disadvantages of the EX-PRESS Glaucoma Filtration Device. EX-PRESS implantation is technically simpler compared with that of trabeculectomy, with fewer surgical steps. Vision recovery has been more rapid after EX-PRESS implantation compared with trabeculectomy. Intraocular pressure variation is lower during the early postoperative period, indicating a more predictable procedure. While efficacy of the EX-PRESS implant has been comparable to trabeculectomy, postoperative complications appear less common after EX-PRESS implantation compared with trabeculectomy. The EX-PRESS Glaucoma Filtration Device appears to be safe and effective in the surgical management of open-angle glaucoma.

  15. The Fundamentals of Waste Water Sludge Characterization and Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Scales, Peter J.; Dixon, David R.; Harbour, Peter J.; Stickland, Anthony D.

    2003-07-01

    The move to greater emphasis on the disposal of waste water sludges through routes such as incineration and the added cost of landfill emplacement puts high demands on dewatering technology for these sludges. A dear problem in this area is that waste water sludges are slow and difficult to dewater and traditional methods of laboratory measurement for prediction of filtration performance are inadequate. This is highly problematic for the design and operational optimisation of centrifuges, filters and settling devices in the waste water industry. The behaviour is assessed as being due to non-linear behaviour of these sludges which negates the use of classical approaches. These approaches utilise the linear portion of a t versus V{sup 2} plot (where t is the time to filtration and V is the specific filtrate volume) to extract a simple Darcian permeability. Without this parameter, a predictive capacity for dewatering using current theory is negated. (author)

  16. Effects of drinking-water filtration on Cryptosporidium seroepidemiology, Scotland.

    Science.gov (United States)

    Ramsay, Colin N; Wagner, Adam P; Robertson, Chris; Smith, Huw V; Pollock, Kevin G J

    2014-01-01

    Continuous exposure to low levels of Cryptosporidium oocysts is associated with production of protective antibodies. We investigated prevalence of antibodies against the 27-kDa Cryptosporidium oocyst antigen among blood donors in 2 areas of Scotland supplied by drinking water from different sources with different filtration standards: Glasgow (not filtered) and Dundee (filtered). During 2006-2009, seroprevalence and risk factor data were collected; this period includes 2007, when enhanced filtration was introduced to the Glasgow supply. A serologic response to the 27-kDa antigen was found for ≈75% of donors in the 2 cohorts combined. Mixed regression modeling indicated a 32% step-change reduction in seroprevalence of antibodies against Cryptosporidium among persons in the Glasgow area, which was associated with introduction of enhanced filtration treatment. Removal of Cryptosporidium oocysts from water reduces the risk for waterborne exposure, sporadic infections, and outbreaks. Paradoxically, however, oocyst removal might lower immunity and increase the risk for infection from other sources.

  17. EFFECT OF KIESELGUHR FILTRATION ON OPTICAL PROPERTIES OF BEER

    Directory of Open Access Journals (Sweden)

    Helena Frančáková

    2013-02-01

    Full Text Available Looks of beer is an important factor which is associated with high clarity. Clarity of beer is a basic precondition of its good marketability and consumer satisfaction. Beer filtration is ideal tool to create required optical properties. There is a high accent on this operation in brewery and minibrewery. The process of filtering removes unwanted haze-active substances in order to increase clarity and overall stability of beer. Objective method to expressing clarity of beer is nephelometric determination of turbidity, which is highly sensitive and achieved by reliable results directly in the units used to express the turbidity values in beer. The objective of our study was to measure haze before and after filtration in various types of beer with different length of lagering. Kieselguhr was used as filtration material. Haze of beer was measured by haze meter in determination under 2 angles and values were expressed in European Brewery Convention units directly.

  18. The renal handling of hemoglobin. I. Glomerular filtration.

    Science.gov (United States)

    Bunn, H F; Esham, W T; Bull, R W

    1969-05-01

    The glomerular filtration of hemoglobin (alpha(2)beta(2)) was studied under conditions in which its dissociation into alphabeta dimers was experimentally altered. Rats receiving hemoglobin treated with the sulfhydryl reagent bis(N-maleimidomethyl) ether (BME) showed a much lower renal excretion and prolonged plasma survival as compared with animals injected with untreated hemoglobin. Plasma disappearance was also prolonged in dogs receiving BME hemoglobin. Gel filtration data indicated that under physiological conditions, BME hemoglobin had impaired subunit dissociation. In addition, BME hemoglobin showed a very high oxygen affinity and a decreased rate of auto-oxidation. Glomerular filtration was enhanced under conditions which favor the dissociation of hemoglobin into dimers. Cat hemoglobin, which forms subunits much more extensively than canine hemoglobin, was excreted more readily by the rat kidney. The renal uptake of (59)Fe hemoglobin injected intra-arterially into rabbits varied inversely with the concentration of the injected dose.

  19. Deashing of coal liquids by sonically assisted filtration

    Energy Technology Data Exchange (ETDEWEB)

    Slomka, B.J.

    1994-10-01

    This project seeks to improve the effectiveness and reduce the cost of coal liquefaction by novel applications of sonic and ultrasonic energy. The specific purpose of this project is to develop and improve means for the economical removal of dispersed solid particles of ash, unreacted coal, and spent catalyst from direct and indirect coal liquefaction resids by using sonic or ultrasonic waves. Product streams containing solids are generated in both direct and indirect coal liquefaction processes. Direct coal liquefaction processes generate liquid products which contain solids including coal-originated mineral matter, unreacted coal, and spent dispersed catalyst. The removal of these solids from a product stream is one of the most difficult problems in direct coal liquefaction processes. On this report, results are discussed for sonically assisted crossflow filtration of V-1067 resid, diluted with No. 2 fuel oil, and sonically assisted batch filtrations of solids concentrates from continuous cross-flow filtration experiments.

  20. A novel insight into membrane fouling mechanism regarding gel layer filtration: Flory-Huggins based filtration mechanism.

    Science.gov (United States)

    Lei, Qian; Zhang, Meijia; Shen, Liguo; Li, Renjie; Liao, Bao-Qiang; Lin, Hongjun

    2016-09-15

    This study linked the chemical potential change to high specific filtration resistance (SFR) of gel layer, and then proposed a novel membrane fouling mechanism regarding gel layer filtration, namely, Flory-Huggins based filtration mechanism. A mathematical model for this mechanism was theoretically deduced. Agar was used as a model polymer for gel formation. Simulation of the mathematical model for agar gel showed that volume fraction of polymer and Flory-Huggins interaction parameter were the two key factors governing the gel SFR, whereas, pH and ionic strength were not related with the gel SFR. Filtration tests of gel layer showed that the total SFR value, effects of pH and ionic strength on the gel SFR well agreed with the perditions of model's simulation, indicating the real occurrence of this mechanism and the feasibility of the proposed model. This mechanism can satisfactorily explain the extremely high SFR of gel layer, and improve fundamental insights into membrane fouling regarding gel layer filtration.

  1. A novel insight into membrane fouling mechanism regarding gel layer filtration: Flory-Huggins based filtration mechanism

    Science.gov (United States)

    Lei, Qian; Zhang, Meijia; Shen, Liguo; Li, Renjie; Liao, Bao-Qiang; Lin, Hongjun

    2016-09-01

    This study linked the chemical potential change to high specific filtration resistance (SFR) of gel layer, and then proposed a novel membrane fouling mechanism regarding gel layer filtration, namely, Flory-Huggins based filtration mechanism. A mathematical model for this mechanism was theoretically deduced. Agar was used as a model polymer for gel formation. Simulation of the mathematical model for agar gel showed that volume fraction of polymer and Flory-Huggins interaction parameter were the two key factors governing the gel SFR, whereas, pH and ionic strength were not related with the gel SFR. Filtration tests of gel layer showed that the total SFR value, effects of pH and ionic strength on the gel SFR well agreed with the perditions of model’s simulation, indicating the real occurrence of this mechanism and the feasibility of the proposed model. This mechanism can satisfactorily explain the extremely high SFR of gel layer, and improve fundamental insights into membrane fouling regarding gel layer filtration.

  2. Development of a novel bead-based 96-well filtration plate competitive immunoassay for the detection of Gentamycin.

    Science.gov (United States)

    Ho, Tien Yu Jessica; Chan, Chia-Chung; Chan, KinGho; Wang, Yu Chieh; Lin, Jing-Tang; Chang, Cheng-Ming; Chen, Chien-Sheng

    2013-11-15

    We developed a sensitive, simple, inexpensive and rapid bead-based immunoassay platform, composed of liposomal nanovesicle amplification system, Gentamycin sulfate beads and 96-well filtration plates. In the beginning of the assay, Gentamycin sulfate beads, Gentamycin sulfate and Gentamycin specific antibody were incubated in a bottom-sealed 96-well filtration plate. After incubation, washing was done by running washing buffer through the unsealed filtration plate with only gravity and the antibody-Gentamycin bead complexes were retained in the plate. Fluorescent dye-loaded protein G-liposomal nanovesicles were then added to specifically bind to antibodies on the retained beads. After washing unbound nanovesicles, millions of fluorescent dye molecules were released by adding a detergent solution to lyse liposomal nanovesicles. The limit of detection (LOD) of this novel detection platform in TBS and in skim milk were 52.65 ng/mL and 14.16 ng/mL, which are both sufficient for detecting the 200 ng/mL Codex maximum residual level (MRL). The dynamic ranges were both from each of their LODs to 100 μg/mL. The 50% inhibition concentrations (IC50) in TBS and skim milk were 199.66 ng/mL and 360.81 ng/mL, respectively. We also demonstrated the good specificity of this platform by comparing detection results between pure Gentamycin solution and a mixture solution of 6 different antibiotics including Gentamycin in skim milk. The entire assay with 60 samples was conducted within 2h. In sum, this novel biosensing platform not only fulfilled most benefits of magnetic bead-based assays, but also was inexpensive and convenient by replacing the magnetic separation with filtration plate separation.

  3. Contribution to the study of the redox couple Np(VI)/Np(V) in the presence of uranium(VI) in solutions of nitric acid and nitrous acid; Contribution a l'etude du comportement redox du couple Np(VI)/Np(V) en presence d'uranium VI dans les solutions constituees d'acide nitrique et d'acide nitreux

    Energy Technology Data Exchange (ETDEWEB)

    Arpigny, S. [CEA Marcoule, Dept. de Radiochimie et Procedes, DRP, 30 (France)

    2001-07-01

    The redox behavior of the Np(VI)/Np(V) couple was the subject of a spectrometric study of the Np(VI) reduction reaction in nitric acid solutions (4 to 5 M) containing variable concentrations (1.5 to 3.5 x 10{sup -3} M) of nitrous acid. A low nitrous acid concentration and a high nitric acid concentration were found to favor the stabilization of Np(VI). The stoichiometric coefficients of nitrous acid and nitric acid in the Np(VI) reduction reaction were determined thermodynamically, although only the reaction order with respect to HNO{sub 2} could be calculated from a kinetic analysis. Adding nitrate ions to a HNO{sub 3}/HNO{sub 2} solution enhanced the stability of neptunium at oxidation state +VI, but also increased the reduction rate. When uranium(VI) was added to the HNO{sub 3}/HNO{sub 2} solutions, the total quantity of neptunium at oxidation state +V (either free or as a Np(V)-U(VI) complex) remained practically unchanged, as did the Np(VI) reduction rate. The electrochemical behavior of the Np(VI)/Np(V) couple was investigated in a weak acidic medium by voltammetry with an ultra-micro-electrode (UME). The oxidation wave limiting current variation was a linear function of the Np(V) concentration when a gold UME was used, but not with a platinum UME; the reduction wave limiting current variation versus the Np(V) concentration was linear with either gold or platinum UMEs. The presence of the Np(V)-U(VI) complex in the neptunium solutions was characterized by a shift in the normal apparent potential of the Np(VI)/Np(V) couple toward anodic potentials consistent with the previously determined values of the complexation constants. (author)

  4. Simulations of Microbial-Enhanced Oil Recovery: Adsorption and Filtration

    DEFF Research Database (Denmark)

    Nielsen, Sidsel Marie; Nesterov, Igor; Shapiro, Alexander

    2014-01-01

    In the context of microbial-enhanced oil recovery (MEOR) with injection of surfactant-producing bacteria into the reservoir, different types of bacteria attachment and growth scenarios are studied using a 1D simulator. The irreversible bacteria attachment due to filtration similar to the deep bed...... applied to filtration model provides formation of two oil banks during recovery. This feature is not reproduced by application of REA model or DBF with growth in attached phase. This makes it possible to select a right model based on the qualitative analysis of the experimental data. A criterion...

  5. The topological filtration of $\\gamma$-structures

    CERN Document Server

    Li, Thomas J X

    2012-01-01

    In this paper we study $\\gamma$-structures filtered by topological genus. $\\gamma$-structures are a class of RNA pseudoknot structures that plays a key role in the context of polynomial time folding of RNA pseudoknot structures. A $\\gamma$-structure is composed by specific building blocks, that have topological genus less than or equal to $\\gamma$, where composition means concatenation and nesting of such blocks. Our main results are the derivation of a new bivariate generating function for $\\gamma$-structures via symbolic methods, the singularity analysis of the solutions and a central limit theorem for the distribution of topological genus in $\\gamma$-structures of given length. In our derivation specific bivariate polynomials play a central role. Their coefficients count particular motifs of fixed topological genus and they are of relevance in the context of genus recursion and novel folding algorithms.

  6. Visual characterization of fouling with bidisperse solution

    NARCIS (Netherlands)

    Ngene, Ikenna S.; Lammertink, Rob G.H.; Wessling, Matthias; Meer, van der Walter G.J.

    2011-01-01

    The cake formation during filtration of a bidisperse polystyrene solution containing 3.3 and 5.7�m particles has been studied. Microfiltration membranes are used in treating feed suspensions with a wide variety of particles, of different types and sizes. These different particles determine the prope

  7. Low-cost multi-stage filtration enhanced by coagulation-flocculation in upflow gravel filtration

    Directory of Open Access Journals (Sweden)

    L. D. Sánchez

    2012-06-01

    Full Text Available This paper assesses the operational and design aspects of coagulation and flocculation in upflow gravel filters (CF-UGF in a multi-stage filtration (MSF plant. This study shows that CF-UGF units improve the performance of MSF considerably, when the system operates with turbidity above 30 NTU. It strongly reduces the load of particulate material before the water enters in the slow sand filters (SSF and therewith avoids short filter runs and prevents early interruption in SSF operations. The removal efficiency of turbidity in the CF-UGF with coagulant was between 85 and 96%, whereas the average efficiency without coagulant dosing was 46% (range: 21–76%. Operating with coagulant also improves the removal efficiency for total coliforms, E-coli and HPC. No reduction was observed in the microbial activity of the SSF, no obstruction of the SSF bed was demonstrated and SSF runs were maintained between 50 and 70 days for a maximum head loss of 0.70 m. The most important advantage is the flexibility of the system to operate with and without coagulant according to the influent turbidity. It was only necessary for 20% of the time to operate with the coagulant. The CF-UGF unit represented 7% of total construction costs and the O&M cost for the use of coagulant represented only 0.3%.

  8. Low-cost multi-stage filtration enhanced by coagulation-flocculation in upflow gravel filtration

    Directory of Open Access Journals (Sweden)

    L. D. Sánchez

    2012-12-01

    Full Text Available This paper assesses the operational and design aspects of coagulation and flocculation in upflow gravel filters (CF-UGF in a multi-stage filtration (MSF plant. This study shows that CF-UGF units improve the performance of MSF considerably, when the system operates with turbidity above 30 NTU. It strongly reduces the load of particulate material before the water enters in the slow sand filters (SSF and therewith avoids short filter runs and prevents early interruption in SSF operations. The removal efficiency of turbidity in the CF-UGF with coagulant was between 85 and 96%, whereas the average efficiency without coagulant dosing was 46% (range: 21–76%. Operating with coagulant also improves the removal efficiency for total coliforms, E-coli and HPC. No reduction was observed in the microbial activity of the SSF, no obstruction of the SSF bed was demonstrated and SSF runs were maintained between 50 and 70 days for a maximum head loss of 0.70 m. The most important advantage is the flexibility of the system to operate with and without coagulant according to the influent turbidity. It was only necessary for 20% of the time to operate with the coagulant. The CF-UGF unit represented 7% of total construction costs and the O&M cost for the use of coagulant represented only 0.3%.

  9. 一般非线性渗流方程正性的扩展%EXPANSION OF POSITIVITY FOR GENERAL NONLINEAR FILTRATION EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    李海峰; 霍振宏; 曹贤通

    2007-01-01

    In this paper,we investigate a behavior of solution of general nonlinear filtration equations.Combining De Giorgi technique with Benilan,Cradall and Pirre(BCP) estimates,we obtain the expansion of positivity for general nonlinear filtration equation.%本文研究一般非线性渗流方程解的一种性态.利用De Giorgi方法与BCP估计相结合,得到了一般非线性渗流方程正性的扩展性质,推广了非线性渗流方程的结果.

  10. Filtration Device for On-Site Collection, Storage and Shipment of Cells from Urine and Its Application to DNA-Based Detection of Bladder Cancer

    DEFF Research Database (Denmark)

    Andersson, Elin; Dahmcke, Christina M; Steven, Kenneth

    2015-01-01

    degradation of cellular content, and low sensitivity due to a high background of normal cells. We present a filtration device, designed for home or point-of-care use, which enables collection, storage and shipment of urinary cells. A special feature of this device is a removable cartridge housing a membrane...... filter, which after filtration of urine can be transferred to a storage unit containing an appropriate preserving solution. In spiking experiments, the use of this device provided efficient recovery of bladder cancer cells with elimination of >99% of excess smaller-sized cells. The performance...

  11. Percolation properties of 3-D multiscale pore networks: how connectivity controls soil filtration processes

    Directory of Open Access Journals (Sweden)

    E. M. A. Perrier

    2010-04-01

    Full Text Available Quantifying the connectivity of pore networks is a key issue not only for modelling fluid flow and solute transport in porous media but also for assessing the ability of soil ecosystems to filter bacteria, viruses and any type of living microorganisms as well inert particles which pose a contamination risk. Straining is the main mechanical component of filtration processes: it is due to size effects, when a given soil retains a conveyed entity larger than the pores through which it is attempting to pass. We postulate that the range of sizes of entities which can be trapped inside soils has to be associated with the large range of scales involved in natural soil structures and that information on the pore size distribution has to be complemented by information on a Critical Filtration Size (CFS delimiting the transition between percolating and non percolating regimes in multiscale pore networks. We show that the mass fractal dimensions which are classically used in soil science to quantify scaling laws in observed pore size distributions can also be used to build 3-D multiscale models of pore networks exhibiting such a critical transition. We extend to the 3-D case a new theoretical approach recently developed to address the connectivity of 2-D fractal networks (Bird and Perrier, 2009. Theoretical arguments based on renormalisation functions provide insight into multi-scale connectivity and a first estimation of CFS. Numerical experiments on 3-D prefractal media confirm the qualitative theory. These results open the way towards a new methodology to estimate soil filtration efficiency from the construction of soil structural models to be calibrated on available multiscale data.

  12. Percolation properties of 3-D multiscale pore networks: how connectivity controls soil filtration processes

    Directory of Open Access Journals (Sweden)

    E. M. A. Perrier

    2010-10-01

    Full Text Available Quantifying the connectivity of pore networks is a key issue not only for modelling fluid flow and solute transport in porous media but also for assessing the ability of soil ecosystems to filter bacteria, viruses and any type of living microorganisms as well inert particles which pose a contamination risk. Straining is the main mechanical component of filtration processes: it is due to size effects, when a given soil retains a conveyed entity larger than the pores through which it is attempting to pass. We postulate that the range of sizes of entities which can be trapped inside soils has to be associated with the large range of scales involved in natural soil structures and that information on the pore size distribution has to be complemented by information on a critical filtration size (CFS delimiting the transition between percolating and non percolating regimes in multiscale pore networks. We show that the mass fractal dimensions which are classically used in soil science to quantify scaling laws in observed pore size distributions can also be used to build 3-D multiscale models of pore networks exhibiting such a critical transition. We extend to the 3-D case a new theoretical approach recently developed to address the connectivity of 2-D fractal networks (Bird and Perrier, 2009. Theoretical arguments based on renormalisation functions provide insight into multi-scale connectivity and a first estimation of CFS. Numerical experiments on 3-D prefractal media confirm the qualitative theory. These results open the way towards a new methodology to estimate soil filtration efficiency from the construction of soil structural models to be calibrated on available multiscale data.

  13. Equivalent Cake Filtration Model%等效滤饼过滤模型

    Institute of Scientific and Technical Information of China (English)

    徐坦; 朱企新; 陈旭; 李文苹

    2008-01-01

    Cake filtration has been widely used in many chemical processes with more non-Newtonian, highly vis- cous and compressible materials involved. Neither traditional nor modern filtration theory can be applied in practice. "Equivalent cake filtration model" is a recently developed mathematical model to describe cake filtration for both Newtonian and non-Newtonian fluids, in either steady or unsteady filtration stages. This model has two strengths: (1) It can be used to determine equivalent capillary radii and predict filtration quality based on the properties of solid/liquid system and operation parameters; and (2) to calculate cake specific resistance and its variations with time at various cake thickness locations.

  14. Filtration and dewatering: review of literature. [117 references

    Energy Technology Data Exchange (ETDEWEB)

    Gala, H. B.; Chiang, S. H.

    1980-09-01

    Filtration and dewatering are important aspects of any chemical process involved in producing solid product from a slurry. However, these operations are not studied in as much detail as other industrial operations like distillation, absorption, etc. In the past, the design of filtration equipment was considered more of an art than science. Only in the last few years have attempts been made to understand the fundamental mechanism underlying these operations. In this review, the present status of filtration and dewatering is discussed, particularly concerning the models used for predicting the rate of filtration and dewatering. Effects of various parameters, size of particles in the slurry, their shape and method of cake formation, etc., on the characteristics of these operations are analyzed. A separate chapter on the use of these processes in coal cleaning is included. Dewatering of fine coal and refuse has attracted a great deal of attention in recent years. Special problems associated with dewatering of fine coal are discussed. Enhanced methods of dewatering are reviewed and finally areas requiring further research are highlighted.

  15. A high-powered view of the filtration barrier.

    Science.gov (United States)

    Peti-Peterdi, János; Sipos, Arnold

    2010-11-01

    Multiphoton excitation fluorescence microscopy is a powerful noninvasive imaging technique for the deep optical sectioning of living tissues. Its application in several intact tissues is a significant advance in our understanding of organ function, including renal pathophysiological mechanisms. The glomerulus, the filtering unit in the kidney, is one good example of a relatively inaccessible and complex structure, with cell types that are otherwise difficult to study at high resolution in their native environment. In this article, we address the application, advantages, and limitations of this imaging technology for the study of the glomerular filtration barrier and the controversy it recently generated regarding the glomerular filtration of macromolecules. More advanced and accurate multiphoton determinations of the glomerular sieving coefficient that are presented here dismiss previous claims on the filtration of nephrotic levels of albumin. The sieving coefficient of 70-kD dextran was found to be around 0.001. Using a model of focal segmental glomerulosclerosis, increased filtration barrier permeability is restricted only to areas of podocyte damage, consistent with the generally accepted role of podocytes and the glomerular origin of albuminuria. Time-lapse imaging provides new details and important in vivo confirmation of the dynamics of podocyte movement, shedding, replacement, and the role of the parietal epithelial cells and Bowman's capsule in the pathology of glomerulosclerosis.

  16. EVALUATION OF FILTRATION AND DISTILLATION METHODS FOR RECYCLING AUTOMOTIVE COOLANT.

    Science.gov (United States)

    This evaluation addresses the product quality, waste reduction, and economic issues involved in recycling automotive and heavy-duty engine coolants at a New Jersey Department of Transportation garage. The specific recycling units evaluated are based on the technologies of filtrat...

  17. Successful Treatment Of Homozygous Familial Hypercholesterolemia Using Cascade Filtration Plasmapheresis

    Directory of Open Access Journals (Sweden)

    Fatih Kardas

    2012-12-01

    Full Text Available OBJECTIVE: The aim of our study is to discuss the efficacy of low-density lipoprotein-cholesterol (LDL-C apheresis procedure using the cascade filtration system for pediatric patients with homozygous familial hypercholesterolemia (FH, and to clarify the adverse effects and difficulties. METHODS: LDL apheresis using the cascade filtration system was performed in 3 pediatric patients with homozygous FH. In total, 120 apheresis sessions were performed for all patients. RESULTS: Cascade filtration therapy significantly reduced the mean LDL-C values from 418 ± 62 mg/dl to 145 ± 43 mg/dl (p<0.05. We determined an acute mean reduction in the plasma levels of total cholesterol (57.9%, LDL cholesterol (70.8%, and high-density lipoprotein (HDL cholesterol (40.7%. Treatments were well tolerated. The most frequent clinical adverse effects were hypotension in 3 sessions (2.5%, chills/feeling cold (1.7% in 2 sessions, and nausea and vomiting in 3 sessions (2.5%. CONCLUSION: Our experience with three patients using the cascade filtration system were, good clinical outcomes, laboratory findings, safety of usage, minor adverse effects and technical problems.

  18. Removal of Inclusions from Molten Aluminum by Supergravity Filtration

    Science.gov (United States)

    Song, Gaoyang; Song, Bo; Yang, Zhanbing; Yang, Yuhou; Zhang, Jing

    2016-09-01

    A new approach to removing inclusions from aluminum melt by supergravity filtration was investigated. The molten aluminum containing MgAl2O4 spinel and coarse Al3Ti particles was isothermally filtered with different gravity coefficients, different filtering times, and various filtering temperatures under supergravity field. When the gravity coefficient G ≥ 50, the alloy samples were divided automatically into two parts: the upper residue and the lower filtered aluminum. All inclusions (MgAl2O4 and Al3Ti particles) were nearly intercepted in the upper residue by filter felt with average pore size of 44.78 μm. The removal efficiencies of oxide inclusions and Al3Ti particles exceeded 98 and 90 pct, respectively, at G ≥ 50, t = 2 minutes, T = 973 K (700 °C). Besides, the yield of purified aluminum was up to 92.1 pct at G = 600, t = 2 minutes, and T = 973 K (700 °C). The calculations of centrifugal pressure indicated that supergravity filtration could effectively overcome the pressure drop without meeting the rigorous requirement of height of molten metal, especially for using the fine-pore filter medium. Moreover, cake-mode filtration was the major mechanism of supergravity filtration of molten metal in this work.

  19. DEM Simulation of Particle Clogging in Fiber Filtration

    Science.gov (United States)

    Tao, Ran; Yang, Mengmeng; Li, Shuiqing

    2015-11-01

    The formation of porous particle deposits plays a crucial role in determining the efficiency of filtration process. In this work, an adhesive discrete element method (DEM), in combination with CFD, is developed to dynamically describe these porous deposit structures and the changed flow field between two parallel fibers under the periodic boundary conditions. For the first time, it is clarified that the structures of clogged particles are dependent on both the adhesion parameter (defined as the ratio of interparticle adhesion to particle inertia) and the Stokes number (as an index of impaction efficiency). The relationship between the pressure-drop gradient and the coordination number along the filtration time is explored, which can be used to quantitatively classify the different filtration regimes, i.e., clean filter stage, clogging stage and cake filtration stage. Finally, we investigate the influence of the fiber separation distance on the particle clogging behavior, which affects the collecting efficiency of the fibers significantly. The results suggest that changing the arrangement of fibers can improve the filter performance. This work has been funded by the National Key Basic Research and Development Program (2013CB228506).

  20. Membrane device and process for mass exchange, separation, and filtration

    Science.gov (United States)

    Liu, Wei; Canfield, Nathan L.

    2016-11-15

    A membrane device and processes for fabrication and for using are disclosed. The membrane device may include a number of porous metal membranes that provide a high membrane surface area per unit volume. The membrane device provides various operation modes that enhance throughput and selectivity for mass exchange, mass transfer, separation, and/or filtration applications between feed flow streams and permeate flow streams.

  1. A scalable approach for high throughput branch flow filtration.

    Science.gov (United States)

    Inglis, David W; Herman, Nick

    2013-05-07

    Microfluidic continuous flow filtration methods have the potential for very high size resolution using minimum feature sizes that are larger than the separation size, thereby circumventing the problem of clogging. Branch flow filtration is particularly promising because it has an unlimited dynamic range (ratio of largest passable particle to the smallest separated particle) but suffers from very poor volume throughput because when many branches are used, they cannot be identical if each is to have the same size cut-off. We describe a new iterative approach to the design of branch filtration devices able to overcome this limitation without large dead volumes. This is demonstrated by numerical modelling, fabrication and testing of devices with 20 branches, with dynamic ranges up to 6.9, and high filtration ratios (14-29%) on beads and fungal spores. The filters have a sharp size cutoff (10× depletion for 12% size difference), with large particle rejection equivalent to a 20th order Butterworth low pass filter. The devices are fully scalable, enabling higher throughput and smaller cutoff sizes and they are compatible with ultra low cost fabrication.

  2. Culture: A Filtration Process during Communication in Education.

    Science.gov (United States)

    de Lange, Rudi

    This paper focuses on the filtration process of culture during communication in education with reference to visual elements. An introduction provides a review of some communication models--graphic representations of theories that attempt to predict and explain the process of communication. These simple models are discussed: Aristotle's model of…

  3. Pressure filtration of ceramic pastes. 4: Treatment of experimental data

    Science.gov (United States)

    Torrecillas, A. S.; Polo, J. F.; Perez, A. A.

    1984-01-01

    The use of data processing method based on the algorithm proposed by Kalman and its application to the filtration process at constant pressure are described, as well as the advantages of this method. This technique is compared to the least squares method. The operation allows the precise parameter adjustment of the equation in direct relationship to the specific resistance of the cake.

  4. Novel filtration mode for fouling limitation in membrane bioreactors.

    Science.gov (United States)

    Wu, Jinling; Le-Clech, Pierre; Stuetz, Richard M; Fane, Anthony G; Chen, Vicki

    2008-08-01

    A novel filtration mode is presented to reduce fouling propensity in membrane bioreactors (MBR). During this mode, an elevated high instantaneous flux (60Lm(-2)h(-1)) is initially applied for a short time (120s), followed by a longer filtration (290s) at lower flux (10.3Lm(-2)h(-1)) and a backwash in each filtration cycle. The mixed mode is expected to limit irreversible fouling as the reversible fouling created during the initial stage appears to protect the membrane. Hydraulic performance and the components of foulants were analyzed and compared with conventional continuous and backwash modes. It was found that the mixed mode featured lower trans-membrane pressure (TMP) after 24h of filtration when compared to other modes. The mixed mode was effective in preventing soluble microbial products (SMP) attaching directly onto the membrane surface, keeping the cake layer weakly compressed, and reducing the mixed liquor suspended solids (MLSS) accumulation on the membrane. This strategy reduced the resistances of both the cake layer and the gel layer. A factorial experimental design was carried out for eight runs with different conditions to identify the major operational parameters affecting the hydraulic performances. The results showed that the value of the flux in the initial high-flux period had the most effect on the performance of the mixed mode: high initial flux (60Lm(-2)h(-1)) led to improved performance.

  5. Removal of Inclusions from Molten Aluminum by Supergravity Filtration

    Science.gov (United States)

    Song, Gaoyang; Song, Bo; Yang, Zhanbing; Yang, Yuhou; Zhang, Jing

    2016-12-01

    A new approach to removing inclusions from aluminum melt by supergravity filtration was investigated. The molten aluminum containing MgAl2O4 spinel and coarse Al3Ti particles was isothermally filtered with different gravity coefficients, different filtering times, and various filtering temperatures under supergravity field. When the gravity coefficient G ≥ 50, the alloy samples were divided automatically into two parts: the upper residue and the lower filtered aluminum. All inclusions (MgAl2O4 and Al3Ti particles) were nearly intercepted in the upper residue by filter felt with average pore size of 44.78 μm. The removal efficiencies of oxide inclusions and Al3Ti particles exceeded 98 and 90 pct, respectively, at G ≥ 50, t = 2 minutes, T = 973 K (700 °C). Besides, the yield of purified aluminum was up to 92.1 pct at G = 600, t = 2 minutes, and T = 973 K (700 °C). The calculations of centrifugal pressure indicated that supergravity filtration could effectively overcome the pressure drop without meeting the rigorous requirement of height of molten metal, especially for using the fine-pore filter medium. Moreover, cake-mode filtration was the major mechanism of supergravity filtration of molten metal in this work.

  6. Separation of nanoparticles: Filtration and scavenging from waste incineration plants.

    Science.gov (United States)

    Förster, Henning; Thajudeen, Thaseem; Funk, Christine; Peukert, Wolfgang

    2016-06-01

    Increased amounts of nanoparticles are applied in products of everyday life and despite material recycling efforts, at the end of their life cycle they are fed into waste incineration plants. This raises the question on the fate of nanoparticles during incineration. In terms of environmental impact the key question is how well airborne nanoparticles are removed by separation processes on their way to the bag house filters and by the existing filtration process based on pulse-jet cleanable fibrous filter media. Therefore, we investigate the scavenging and the filtration of metal nanoparticles under typical conditions in waste incineration plants. The scavenging process is investigated by a population balance model while the nanoparticle filtration experiments are realized in a filter test rig. The results show that depending on the particle sizes, in some cases nearly 80% of the nanoparticles are scavenged by fly ash particles before they reach the bag house filter. For the filtration step dust cakes with a pressure drop of 500Pa or higher are found to be very effective in preventing nanoparticles from penetrating through the filter. Thus, regeneration of the filter must be undertaken with care in order to guarantee highly efficient collection of particles even in the lower nanometre size regime.

  7. Modelling Real World Using Stochastic Processes and Filtration

    Directory of Open Access Journals (Sweden)

    Jaeger Peter

    2016-03-01

    Full Text Available First we give an implementation in Mizar [2] basic important definitions of stochastic finance, i.e. filtration ([9], pp. 183 and 185, adapted stochastic process ([9], p. 185 and predictable stochastic process ([6], p. 224. Second we give some concrete formalization and verification to real world examples.

  8. Reaching ultra low phosphorus concentrations by filtration techniques

    NARCIS (Netherlands)

    Scherrenberg, S.M.

    2011-01-01

    This research deals with tertiary treatment techniques used for the removal of phosphorus from wastewater treatment plant (WWTP) effluent. The main objective of this research is to obtain ultra low total phosphorus (<0.15 mg total phosphorus/L) concentrations by coagulation, flocculation and filtrat

  9. Experiences on dual media filtration of WWTP effluent.

    Science.gov (United States)

    Scherrenberg, S M; Postma, P; Neef, R; Menkveld, H W H; Bechger, M; van der Graaf, J H J M

    2011-01-01

    This research is legislation driven by the European Water Framework Directive (WFD) and the Dutch Fourth Memorandum on Water Management. The objective of this research is to achieve the removal of total nitrogen and total phosphorus by Dual Media Filtration. The target value during this research for total nitrogen is 2.2 mg/L and for total phosphorus 0.15 mg/L. The results show that for NOx-N concentrations in the WWTP effluent up to 10 mg/L, a stable operation of the process can be reached with removal rates of 80% to 90%. The maximum nitrogen removal rate was 3.5 kg N/(m3.d). Above 10 mg/L a risk of filter bed clogging occurred. When the orthophosphorus concentration in the WWTP effluent exceeds the maximum of 0.3 mg/L, the total phosphorus concentration in the filtrate water will exceed the target value of 0.15 mg P-total/L. Temperature has a large impact in the phosphorus removal; the optimum temperature range is within 13 degrees C-18 degrees C. In conclusion, Dual Media Filtration is capable of producing reusable water with total phosphorus concentrations of WWTP effluent with steady concentrations for orthophosphorus (<0.3 mg PO4-P/L). To reach total nitrogen concentrations in the filtrate water of <2.2 mg/L a NOx-N removal efficiency of nearly 100% is required.

  10. RENAL RESERVE FILTRATION CAPACITY IN GROWTH-HORMONE DEFICIENT SUBJECTS

    NARCIS (Netherlands)

    DULLAART, RPF; MEIJER, S; MARBACH, P; SLUITER, WJ

    In normal subjects, the glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) acutely increase in response to infusion of amino acids and to low doses of dopamine. It is uncertain whether circulatory growth hormone (GH) is a permissive factor for these stimulatory effects. GFR and

  11. EVALUATION OF FILTRATION AND DISTILLATION METHODS FOR RECYCLING AUTOMOTIVE COOLANT.

    Science.gov (United States)

    This evaluation addresses the product quality, waste reduction, and economic issues involved in recycling automotive and heavy-duty engine coolants at a New Jersey Department of Transportation garage. The specific recycling units evaluated are based on the technologies of filtrat...

  12. Removal of Brettanomyces bruxellensis from red wine using membrane filtration

    Science.gov (United States)

    While sulfites help limit growth of the spoilage yeast, Brettanomyces, SO2 has been reported to decrease cell size, thereby potentially decreasing the porosities of filtration membranes required for removal. B. bruxellensis strains B1b and F3 were inoculated into red wines and after 12 days, half th...

  13. Simulation of impaction filtration of aerosol droplets in porous media

    NARCIS (Netherlands)

    Ghazaryan, Lilya; Lopez Penha, David J.; Geurts, Bernard J.; Stolz, Steffen; Winkelmann, Christoph; Pereira, J.C.F.; Sequeira, A.; Pereira, J.M.C.

    2010-01-01

    We report on the development of a method to simulate from first principles the particle filtration efficiency of filters that are composed of structured porous media. We assume that the ratio of particle density to the fluid density is high. We concentrate on the motion of the particles in a laminar

  14. An improved method to isolate lichen algae by gel filtration.

    Science.gov (United States)

    Pérez, M J; Vicente, C; Legaz, M E

    1985-08-01

    Photobiont cells of the lichen Evernia prunastri have completely been separated from their fungal partner by filtration through a bed of Sepharose 2B. Both mannitol and ribitol have been quantified by gas-liquid chromatography in the different steps of the isolation procedure. Absence of mannitol, which is exclusively produced by the mycobiont, has been used as the best probe to monitor isolation.

  15. Mechanism of reduced glomerular filtration rate in chronic malnutrition.

    Science.gov (United States)

    Ichikawa, I; Purkerson, M L; Klahr, S; Troy, J L; Martinez-Maldonado, M; Brenner, B M

    1980-05-01

    To determine the physiological basis for the low glomerular filtration rate in chronic malnutrition, micropuncture studies were performed in Munich-Wistar rats chronically pair-fed isocaloric diets of either low (group 1, nine rats) or high protein content (group 2, nine rats). Despite the absence of hypoalbuminemia, average values for single nephron and total kidney glomerular filtration rate were nearly 35% lower in group 1 than in group 2. Mean values for glomerular capillary and Bowman's space hydraulic pressures were essentially identical in the two groups, thereby excluding glomerular transcapillary hydraulic pressure difference as the cause for the low filtration rates in group 1 animals. On the other hand, average glomerular capillary plasma flow rate and glomerular capillary ultrafiltration coefficient were significantly lower (by approximately 25 and approximately 50%, respectively) in group 1 than in group 2. The fall in glomerular capillary plasma flow rate was the consequence of increased afferent and efferent arteriolar resistances. Plasma and erythrocyte volumes were found to be equal in five additional pairs of group 1 and group 2 rats. Thus, the substantial alterations in the ultrafiltration coefficient, glomerular capillary plasma flow rate, and renal arteriolar resistances responsible for the low filtration rate in group 1 animals were not merely a consequence of decreased circulating blood or plasma volumes. Mean values for glomerular cross sectional area were significantly lower in group 1 than in group 2 despite similar values for kidney weight in the two groups. This reduction in glomerular cross sectional area in group 1 rats is presumed to reflect a decrease in effective filtration surface area and therefore likely accounts, at least in part, for the decline in ultrafiltration coefficient observed in this group.Finally, since the daily caloric intake of group 2 animals was restricted because of pair feeding requirements tied to the group 1

  16. Treatment of exhausted tannin liquors of the leather industry by nano filtration; Tratamiento por nanofiltracion de los licores agotados de taninos en la industria del curtido

    Energy Technology Data Exchange (ETDEWEB)

    Adzet, J.; Buonomenna, M. G.; Cassano, A.; Drioli, E.; Molineri, R.

    2002-07-01

    The use of a nano filtration process is described in order to rationalize the vegetable tonnage step in leather industry through the recovery of tannins from the exhausted baths and their reuse as tanning agents. The results obtained on pilot scale using a membrane module, identified after a screening of various nano filtration membranes, the operating and fluid-dynamic conditions and the mass balance of the nano filtration process are reported and discussed. Skins treated with the recovered solutions revealed chemical and physical parameters very similar to those measured on control skins tanned with standard solutions. According to the obtained results, it is possible to suggest a process scheme that, starting from the exhausted tanning baths, through a nano filtration membrane purification/concentration, permits to increase the tannin/non tannin ratio of the retentate solution. Advantages are in terms of: reduction of environmental impact, simplification of cleaning-up processes of wastewaters, decrease of disposal costs, saving of chemicals and water. (Author)

  17. Impacts of extreme flooding on riverbank filtration water quality.

    Science.gov (United States)

    Ascott, M J; Lapworth, D J; Gooddy, D C; Sage, R C; Karapanos, I

    2016-06-01

    Riverbank filtration schemes form a significant component of public water treatment processes on a global level. Understanding the resilience and water quality recovery of these systems following severe flooding is critical for effective water resources management under potential future climate change. This paper assesses the impact of floodplain inundation on the water quality of a shallow aquifer riverbank filtration system and how water quality recovers following an extreme (1 in 17 year, duration >70 days, 7 day inundation) flood event. During the inundation event, riverbank filtrate water quality is dominated by rapid direct recharge and floodwater infiltration (high fraction of surface water, dissolved organic carbon (DOC) >140% baseline values, >1 log increase in micro-organic contaminants, microbial detects and turbidity, low specific electrical conductivity (SEC) 400% baseline). A rapid recovery is observed in water quality with most floodwater impacts only observed for 2-3 weeks after the flooding event and a return to normal groundwater conditions within 6 weeks (lower fraction of surface water, higher SEC, lower DOC, organic and microbial detects, DO). Recovery rates are constrained by the hydrogeological site setting, the abstraction regime and the water quality trends at site boundary conditions. In this case, increased abstraction rates and a high transmissivity aquifer facilitate rapid water quality recoveries, with longer term trends controlled by background river and groundwater qualities. Temporary reductions in abstraction rates appear to slow water quality recoveries. Flexible operating regimes such as the one implemented at this study site are likely to be required if shallow aquifer riverbank filtration systems are to be resilient to future inundation events. Development of a conceptual understanding of hydrochemical boundaries and site hydrogeology through monitoring is required to assess the suitability of a prospective riverbank filtration

  18. Filtration effectiveness of HVAC systems at near-roadway schools.

    Science.gov (United States)

    McCarthy, M C; Ludwig, J F; Brown, S G; Vaughn, D L; Roberts, P T

    2013-06-01

    Concern for the exposure of children attending schools located near busy roadways to toxic, traffic-related air pollutants has raised questions regarding the environmental benefits of advanced heating, ventilation, and air-conditioning (HVAC) filtration systems for near-road pollution. Levels of black carbon and gaseous pollutants were measured at three indoor classroom sites and at seven outdoor monitoring sites at Las Vegas schools. Initial HVAC filtration systems effected a 31-66% reduction in black carbon particle concentrations inside three schools compared with ambient air concentrations. After improved filtration systems were installed, black carbon particle concentrations were reduced by 74-97% inside three classrooms relative to ambient air concentrations. Average black carbon particle concentrations inside the schools with improved filtration systems were lower than typical ambient Las Vegas concentrations by 49-96%. Gaseous pollutants were higher indoors than outdoors. The higher indoor concentrations most likely originated at least partially from indoor sources, which were not targeted as part of this intervention. Recent literature has demonstrated adverse health effects in subjects exposed to ambient air near major roadways. Current smart growth planning and infill development often require that buildings such as schools are built near major roadways. Improving the filtration systems of a school's HVAC system was shown to decrease children's exposure to near-roadway diesel particulate matter. However, reducing exposure to the gas-phase air toxics, which primarily originated from indoor sources, may require multiple filter passes on recirculated air. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  19. Reduced quenching and extraction time for mammalian cells using filtration and syringe extraction.

    Science.gov (United States)

    Hernández Bort, Juan A; Shanmukam, Vinoth; Pabst, Martin; Windwarder, Markus; Neumann, Laura; Alchalabi, Ali; Krebiehl, Guido; Koellensperger, Gunda; Hann, Stephan; Sonntag, Denise; Altmann, Friedrich; Heel, Christine; Borth, Nicole

    2014-07-20

    In order to preserve the in vivo metabolite levels of cells, a quenching protocol must be quickly executed to avoid degradation of labile metabolites either chemically or biologically. In the case of mammalian cell cultures cultivated in complex media, a wash step previous to quenching is necessary to avoid contamination of the cell pellet with extracellular metabolites, which could distort the real intracellular concentration of metabolites. This is typically achieved either by one or multiple centrifugation/wash steps which delay the time until quenching (even harsh centrifugation requires several minutes for processing until the cells are quenched) or filtration. In this article, we describe and evaluate a two-step optimized protocol based on fast filtration by use of a vacuum pump for quenching and subsequent extraction of intracellular metabolites from CHO (Chinese hamster ovary) suspension cells, which uses commercially available components. The method allows transfer of washed cells into liquid nitrogen within 10-15s of sampling and recovers the entire extraction solution volume. It also has the advantage to remove residual filter filaments in the final sample, thus preventing damage to separation columns during subsequent MS analysis. Relative to other methods currently used in the literature, the resulting energy charge of intracellular adenosine nucleotides was increased to 0.94 compared to 0.90 with cold PBS quenching or 0.82 with cold methanol/AMBIC quenching.

  20. High flux filtration medium based on nanofibrous substrate with hydrophilic nanocomposite coating.

    Science.gov (United States)

    Wang, Xuefen; Chen, Xuming; Yoon, Kyunghwan; Fang, Dufei; Hsiao, Benjamin S; Chu, Benjamin

    2005-10-01

    A novel high flux filtration medium, consisting of a three-tier composite structure, i.e., a nonporous hydrophilic nanocomposite coating top layer, an electrospun nanofibrous substrate midlayer, and a conventional nonwoven microfibrous support, was demonstrated for oil/water emulsion separations for the first time. The nanofibrous substrate was prepared by electrospinning of poly(vinyl alcohol) (PVA) followed by chemical cross-linking with glutaraldehyde (GA) in acetone. The resulting cross-linked PVA substrates showed excellent water resistance and good mechanical properties. The top coating was based on a nanocomposite layer containing hydrophilic polyether-b-polyamide copolymer or a cross-linked PVA hydrogel incorporated with surface-oxidized multiwalled carbon nanotubes (MWNTs). Scanning electron microscopy (SEM) examinations indicated that the nanocomposite layer was nonporous within the instrumental resolution and MWNTs were well dispersed in the polymer matrix. Oil/ water emulsion tests showed that this unique type of filtration media exhibited a high flux rate (up to 330 L/m2-h at the feed pressure of 100 psi) and an excellent total organic solute rejection rate (99.8%) without appreciable fouling. The increase in the concentration of surface-oxidized MWNT in the coating layer generally improves the flux rate, which can be attributed to the generation of more effective hydrophilic nanochannels for water passage in the composite membranes.

  1. Syringe filtration methods for examining dissolved and colloidal trace element distributions in remote field locations

    Science.gov (United States)

    Shiller, Alan M.

    2003-01-01

    It is well-established that sampling and sample processing can easily introduce contamination into dissolved trace element samples if precautions are not taken. However, work in remote locations sometimes precludes bringing bulky clean lab equipment into the field and likewise may make timely transport of samples to the lab for processing impossible. Straightforward syringe filtration methods are described here for collecting small quantities (15 mL) of 0.45- and 0.02-microm filtered river water in an uncontaminated manner. These filtration methods take advantage of recent advances in analytical capabilities that require only small amounts of waterfor analysis of a suite of dissolved trace elements. Filter clogging and solute rejection artifacts appear to be minimal, although some adsorption of metals and organics does affect the first approximately 10 mL of water passing through the filters. Overall the methods are clean, easy to use, and provide reproducible representations of the dissolved and colloidal fractions of trace elements in river waters. Furthermore, sample processing materials can be prepared well in advance in a clean lab and transported cleanly and compactly to the field. Application of these methods is illustrated with data from remote locations in the Rocky Mountains and along the Yukon River. Evidence from field flow fractionation suggests that the 0.02-microm filters may provide a practical cutoff to distinguish metals associated with small inorganic and organic complexes from those associated with silicate and oxide colloids.

  2. The glomerular filtration rate during pregnancy : Saline infusion enhances the glomerular filtration rate in the pregnant rat

    NARCIS (Netherlands)

    Faas, MM; Schuiling, GA; Klok, PA; Valkhof, N; Bakker, WW

    1996-01-01

    The glomerular filtration rate (GFR) of pregnant rats is generally believed to exceed non-pregnant values. This notion is primarily based upon standard inulin clearances. However, the inulin clearance requires continuous infusion of inulin usually dissolved in saline. Since saline infusion per se in

  3. Stochastic modeling of filtrate alkalinity in water filtration devices: Transport through micro/nano porous clay based ceramic materials

    Science.gov (United States)

    Clay and plant materials such as wood are the raw materials used in manufacture of ceramic water filtration devices around the world. A step by step manufacturing procedure which includes initial mixing, molding and sintering is used. The manufactured ceramic filters have numerous pores which help i...

  4. Surface patterning of polymeric separation membranes and its influence on the filtration performance

    Science.gov (United States)

    Maruf, Sajjad

    Polymeric membrane based separation technologies are crucial for addressing the global issues such as water purification. However, continuous operations of these processes are often hindered by fouling which increases mass transport resistance of the membrane to permeation and thus the energy cost, and eventually replacement of the membrane in the system. In comparison to other anti-fouling strategies, the use of controlled surface topography to mitigate fouling has not been realized mainly due to the lack of methods to create targeted topography on the porous membrane surface. This thesis aims to develop a new methodology to create surface-patterned polymeric separation membrane to improve their anti-fouling characteristics during filtration. First, successful fabrication of sub-micron surface patterns directly on a commercial ultrafiltration (UF) membrane surface using nanoimprint lithographic (NIL) technique was demonstrated. Comprehensive filtration studies revealed that the presence of these sub-micron surface patterns mitigates not only the onset of colloidal particle deposition, but also lowers the rate of growth of cake layer after initial deposition, in comparison with un-patterned membranes. The anti-fouling effects were also observed for model protein solutions. Staged filtration experiments, with backwash cleaning, revealed that the permeate flux of the patterned membrane after protein fouling was considerably higher than that of the pristine or un-patterned membrane. In addition to the surface-patterning of UF membranes, successful fabrication of a surface-patterned thin film composite (TFC) membrane was shown for the first time. A two-step fabrication process was carried out by (1) nanoimprinting a polyethersulfone (PES) support using NIL, and (2) forming a thin dense film atop the PES support via interfacial polymerization (IP). Fouling experiments suggest that the surface patterns alter the hydrodynamics at the membrane-feed interface, which is

  5. Stabilization of solutions of feather keratins by sodium dodecyl sulphate

    NARCIS (Netherlands)

    Schrooyen, P.M.M.; Dijkstra, Pieter J.; Oberthür, Radulf C.; Bantjes, A.; Bantjes, Adriaan; Feijen, Jan

    2001-01-01

    Feather keratins were extracted from chicken feathers with aqueous solutions of urea and 2-mercaptoethanol. After filtration of the insoluble residue, a feather keratin solution was obtained. Removal of 2-mercaptoethanol and urea by dialysis resulted in aggregation of the keratin polypeptide chains

  6. Uncertainty and Sensitivity Analysis of Filtration Models for Non-Fickian transport and Hyperexponential deposition

    DEFF Research Database (Denmark)

    Yuan, Hao; Sin, Gürkan

    2011-01-01

    filtration coefficients, while deposition is more sensitive to filtration coefficients. More experimental measurements at these moments are suggested to determine dispersion coefficients more accurately. More measurements of the steady-state effluent concentration or deposition are suggested to determine...

  7. Characterization, Washing, Leaching, and Filtration of C-104 Sludge

    Energy Technology Data Exchange (ETDEWEB)

    KP Brooks; PR Bredt; GR Golcar; SA Hartley; LK Jagoda; KG Rappe; MW Urie

    2000-06-09

    Approximately 1,400 g of wet Hanford Tank C-104 Sludge was evaluated by Battelle for the high-level waste (HLW) pretreatment processes of ultrafiltration, dilute caustic washing, and elevated-temperature caustic leaching. The filterability of diluted C-104 sludge was measured with a 0.1-{micro}m sintered metal Mott filter using a 24-inch-long, single-element, crossflow filtration system (cells unit filter [CUF]). While the filtrate was being recirculated prior to washing and leaching, a 6.9 wt% solids slurry was evaluated with a matrix of seven 1-hour conditions of varying trans-membrane pressure (30 to 70 psid) and axial velocity (9 to 15 ft/s). The filtrate flux and backpulse efficiency were determined for each condition. The slurry was concentrated to 23 wt% solids, a second matrix of six 1-hour conditions was performed, and data analogous to that recorded in the first matrix were obtained. The low-solids-concentration matrix produced filtrate flux rates that ranged from 0.038 to 0.083 gpm/ft{sup 2}. The high-solids-concentration matrix produced filtrate flux rates that ranged from 0.0095 to 0.0172 gpm/ft{sup 2}. In both cases, the optimum filtrate flux was at the highest axial velocity (15 ft/s) and transmembrane pressure had little effect. Nearly all of the measured filtrate fluxes were more than an order of magnitude greater than the required plant flux for C-104 of 0.00126 gpm/ft{sup 2}. In both matrices, the filtrate flux appeared to be proportional to axial velocity, and the permeability appeared to be inversely proportional to the trans-membrane pressure. The first test condition was repeated as the last test condition for each matrix. In both cases, there was a significant decrease in filtrate flux, indicating some filter fouling during the test matrix that could not be removed by backpulsing alone, although the backpulse number and duration were not optimized. Following testing of these two matrices, the material was washed within the CUF by

  8. Static and dynamic filtrations of different clay, electrolytes, polymer systems; Filtrations statiques et dynamiques de differents systemes argile, electrolytes, polymere

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.

    1996-04-16

    Filtration properties of model drilling fluids composed of water, clays, electrolytes and water soluble polymers have been studied in static and dynamic conditions on paper filters and rock slices. Filtration experiments combined with cake observations by cryo-S.E.M. and T.E.M., show the influence of the size shape of clay particles as well as their associating mode in suspension, on the texture of the cake, its permeability, and relaxation properties. These parameters depend on the nature of the electrolyte. The polymer reduces the cake permeability by enhancing the dispersion of the clay within the suspension, but mainly by plugging the porous network due its auto aggregation properties. The cake construction in dynamic conditions, is related to the state of aggregation of the initial suspension, its poly-dispersity, its sensitivity to shear rates, and also, to the permeability of the cake built at the beginning of the filtration. In all cases, the rate of thickening of the cake is slower and larger filtrate volumes are obtained compared to the static conditions. Shear rate has two effects: first, to dissociate the weak aggregates in suspension, second, to impose a size selection of the particles in the case of a poly-dispersed suspension. At high shear rates, a cake of constant thin thickness is quickly obtained. The thickness of this limiting cake depends on the fraction of small particles present in suspension, or that can be formed by dissociation of weak aggregates under shear rate. The permeability of this limiting cake formed in dynamic conditions is, as in static conditions, controlled by the size and the shape of the particles that form the cake or by the presence of a build loss reducer water soluble polymer. Filtrations carried out on Fontainebleau sandstones allow to visualize the internal cake and to precise the risks of formation damage by the drilling fluid. (author) 127 refs.

  9. On influence of some ecological factors on intensity of the oyster filtration (Ostrea edulis

    Directory of Open Access Journals (Sweden)

    N. A. Sitnik

    2009-10-01

    Full Text Available Quantitative regularities of the filtration feeding of the Black Sea oyster depending on some ecological factors were studied. Influence of food concentration on filtration activity of shellfish is described. Dependences of filtration speed are certain on the body mass of oysters under different temperature conditions were found. The seasonal changes of its intensity in the Kerch Strait and the Donuzlav Estuary are illustrated. Influence of water salinity on filtration activity of the oyster is established.

  10. Particulate Matter Filtration Design Considerations for Crewed Spacecraft Life Support Systems

    Science.gov (United States)

    Agui, Juan H.; Vijayakumar, R.; Perry, Jay L.

    2016-01-01

    Particulate matter filtration is a key component of crewed spacecraft cabin ventilation and life support system (LSS) architectures. The basic particulate matter filtration functional requirements as they relate to an exploration vehicle LSS architecture are presented. Particulate matter filtration concepts are reviewed and design considerations are discussed. A concept for a particulate matter filtration architecture suitable for exploration missions is presented. The conceptual architecture considers the results from developmental work and incorporates best practice design considerations.

  11. HGMF of 10-L solutions. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Larkin, K.A.

    1995-04-27

    This test plan describes the activities associated with the High Gradient Magnetic Filtration (HGMF) of plutonium-bearing solutions (10-L). The 10-L solutions were received from Argonne National Laboratories in 1972, are acidic, and are considered unstable. Tests on a HGMF were conducted in the 1980`s for N-reactor. These tests suggested that this system would be useful for the removal of transuranic elements from solutions. The purpose of this testing activity is to show that HGMF is an applicable method of removing plutonium precipitates from solution.

  12. 40 CFR 141.717 - Pre-filtration treatment toolbox components.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Pre-filtration treatment toolbox... Cryptosporidium Requirements for Microbial Toolbox Components § 141.717 Pre-filtration treatment toolbox... softening stages prior to filtration. Both softening stages must treat the entire plant flow taken from...

  13. 21 CFR 211.46 - Ventilation, air filtration, air heating and cooling.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Ventilation, air filtration, air heating and... Buildings and Facilities § 211.46 Ventilation, air filtration, air heating and cooling. (a) Adequate... holding of a drug product. (c) Air filtration systems, including prefilters and particulate matter...

  14. 75 FR 28295 - Cummins Filtration, Including On-Site Leased Workers From Manpower and Spherion Staffing...

    Science.gov (United States)

    2010-05-20

    ... Employment and Training Administration Cummins Filtration, Including On-Site Leased Workers From Manpower and... workers of Cummins Filtration, including on-site leased workers from Manpower, Lake Mills, Iowa. The... Mills, Iowa location of Cummins Filtration to provide procurement and inventory management services...

  15. Facilitating community water supply treatment : from transferring filtration technology to multi-stakeholder learning

    NARCIS (Netherlands)

    Visscher, J.T.

    2006-01-01

    For more than a quarter of a century, IRC has been supporting the development of Slow Sand Filtration (SSF) and more recently, together with CINARA, the pioneering of Multi-Stage Filtration (MSF) - a combination of Gravel Filtration and SSF that has been shown to have great potential as an effective

  16. 77 FR 38857 - Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units of Normal...

    Science.gov (United States)

    2012-06-29

    ... COMMISSION Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units of Normal..., Inspection, and Testing Criteria for Air Filtration and Adsorption Units of Normal Atmosphere Cleanup Systems..., entitled, ``Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units of...

  17. 76 FR 82323 - Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units

    Science.gov (United States)

    2011-12-30

    ... COMMISSION Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units AGENCY: Nuclear...-1274, ``Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units of....'' This guide applies to the design, inspection, and testing of air filtration and iodine adsorption...

  18. Facilitating community water supply treatment : from transferring filtration technology to multi-stakeholder learning

    NARCIS (Netherlands)

    Visscher, J.T.

    2006-01-01

    For more than a quarter of a century, IRC has been supporting the development of Slow Sand Filtration (SSF) and more recently, together with CINARA, the pioneering of Multi-Stage Filtration (MSF) - a combination of Gravel Filtration and SSF that has been shown to have great potential as an effective

  19. Study of the combining adsorption-micro filtration process for the treatment of coloured waters

    Energy Technology Data Exchange (ETDEWEB)

    Addaou, A.; Laajeb, A.; Lahsini, A.; Bentama, J.; Rodriguez, M. A.

    2012-11-01

    Generally textile effluents are highly coloured, contain non-biodegradable compounds and they have high content of solid wastes, comprising fibres and paper wastes. The discharge of such effluents in the environment is worrying for both toxicological and esthetical reasons. The aim of the present work is to study the performances of the combining micro filtration-adsorption process for the treatment of coloured waters. Methylene Blue (MB) was used as model compound. The effects of significant operating parameters such as transmembrane pressure (TMP) and bentonite concentration on the process performance characterized by flux and rejection factor were investigated. Experiments carried out with Methylene Blue solutions confirmed the potential of this combined process for the treatment of dyed waters. (Author) 13 refs.

  20. A Stochastic Theory for Deep Bed Filtration Accounting for Dispersion and Size Distributions

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Bedrikovetsky, P. G.

    2010-01-01

    We develop a stochastic theory for filtration of suspensions in porous media. The theory takes into account particle and pore size distributions, as well as the random character of the particle motion, which is described in the framework of the theory of continuous-time random walks (CTRW......). In the limit of the infinitely many small walk steps we derive a system of governing equations for the evolution of the particle and pore size distributions. We consider the case of concentrated suspensions, where plugging the pores by particles may change porosity and other parameters of the porous medium....... A procedure for averaging of the derived system of equations is developed for polydisperse suspensions with several distinctive particle sizes. A numerical method for solution of the flow equations is proposed. Sample calculations are applied to compare the roles of the particle size distribution...

  1. Mathematical models of membrane fouling in cross-flow micro-filtration

    Directory of Open Access Journals (Sweden)

    Mónica Jimena Ortíz Jerez

    2010-04-01

    Full Text Available The greatest difficulty arising during cross-flow micro-filtration is the formation of a cake layer on the membrane sur-face (also called fouling, thereby affecting system performance. Fouling has been related to permeate flux decay re-sulting from changes in operating variables. Many articles have been published in an attempt to explain this phe-nomenon but it has not yet been fully understood because it depends on specific solution/membrane interactions and differing parameters. This work was aimed at presenting an analytical review of recently published mathematical models to explain fouling. Although the reviewed models can be adjusted to any type of application, a simple “con-centration polarisation” model is advisable in the particular case of tropical fruit juices for describing the insoluble solids being deposited on membrane surface.

  2. Transparent conducting film: Effect of vacuum filtration of carbon nanotube suspended in oleum

    Indian Academy of Sciences (India)

    Tsuyoshi Saotome; Hansang Kim; Zhe Wang; David Lashmore; H Thomas Hahn

    2011-07-01

    Vacuum filtration process to fabricate a transparent conducting carbon nanotube (CNT) film is reported. A CNT mat, which is a fibrous sheet of long multi-walled carbon nanotubes (MWNT), was prepared and dispersed in oleum by solution-sonication. The suspension was then vacuum filtered to obtain a thin MWNT layer with improved dispersion. Sheet resistance of the obtained MWNT layer was increased despite the improved dispersion. SEM micrographs and energy dispersive spectroscopy results indicated that the increase of the sheet resistance could be attributed to degradation and oxidation of the MWNT bundles. Though the chemical approach in this study did not improve the electrical property of the CNT mat, a mechanical approach proposed in our recent work was deemed suitable to enhance optical and electrical properties of the CNT mat.

  3. Synthesis of soft shell poly(styrene) colloids for filtration experiments

    DEFF Research Database (Denmark)

    Hinge, Mogens

    Separating a solid from a liquid is an important unit operation in many different industries e.g. mining, chemical, pharmaceutical and food industries. Solid liquid separation can roughly be divided into three groups. 1) Separation by gravity forces e.g. sedimentation, centrifugation, 2) Separation...... of the core-shell colloids on the filtration dewatering behavior. The third and final series has been chosen to investigate the effect from a non-ionic water swollen material. The model colloids from series one and two were synthesized by a free-radicale surfactant-free emulsion co-polymerization process...... of acrylic acid monomer added to the synthesis. Further it was shown that it is possible to increase the PS core diameter by increasing the ionic strength of the synthesis solution. The model colloids from series three were synthesized by a two step free-radical surfactant-free emulsion polymerization (SFEP...

  4. NASA Lunar Dust Filtration and Separations Workshop Report

    Science.gov (United States)

    Agui, Juan H.; Stocker, Dennis P.

    2009-01-01

    NASA Glenn Research Center hosted a 2.5-day workshop, entitled "NASA Lunar Dust Filtration and Separations Workshop" at the Ohio Aerospace Institute in Cleveland, Ohio, on November 18 to 20, 2008. The purpose of the workshop was to address the issues and challenges of particulate matter removal from the cabin atmospheres in the Altair lunar lander, lunar habitats, and in pressurized rovers. The presence of lunar regolith dust inside the pressurized volumes was a theme of particular interest. The workshop provided an opportunity for NASA, industry experts, and academia to identify and discuss the capabilities of current and developing air and gas particulate matter filtration and separations technologies as they may apply to NASA s needs. A goal of the workshop was to provide recommendations for strategic research areas in cabin atmospheric particulate matter removal and disposal technologies that will advance and/or supplement the baseline approach for these future lunar surface exploration missions.

  5. Cast Steel Filtration Trials Using Ceramic-Carbon Filters

    Directory of Open Access Journals (Sweden)

    Lipowska B.

    2014-12-01

    Full Text Available Trials of cast steel filtration using two types of newly-developed foam filters in which carbon was the phase binding ceramic particles have been conducted. In one of the filters the source of carbon was flake graphite and coal-tar pitch, while in the other one graphite was replaced by a cheaper carbon precursor. The newly-developed filters are fired at 1000°C, i.e. at a much lower temperature than the currently applied ZrO2-based filters. During filtration trials the filters were subjected to the attack of a flowing metal stream having a temperature of 1650°C for 30 seconds.

  6. Particle flocculation and filtration by high-gradient magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Tsouris, C. [Oak Ridge National Lab., TN (United States); Yiacoumi, S. [Georgie Inst. of Technology, Atlanta, GA (United States)

    1997-01-01

    Flocculation and filtration of micrometer-sized particles in a high-gradient magnetic field (HGMF) were investigated. Experiments were conducted using a cryogenic magnet of 6 Tesla maximum strength. Hematite particles were used for flocculation and filtration experiments. A new approach of using magnetic fields to enhance separation of weakly magnetic particles was also investigated. This approach is based on magnetic seeding which involves flocculation of existing non-magnetic particles with injected paramagnetic particles. A particle-flocculation model was developed based on trajectory analysis. External forces due to gravity and magnetism, and interparticle forces such as electrostatic, hydrodynamic, magnetic dipole, and van der Waals forces, were taken into consideration in these models.

  7. High gradient magnetic filtration and separation. Part II

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, D.

    The paper contains the second part of a two part paper in which the developing role of high grade magnetic filtration and separation (HGMF/S) is reviewed. Part I discussed the increasing potential for the technique and outlined the basic theory behind it. Part II describes the practical application of the technique with particular reference to the beneficiation of fine coal. Aspects considered are: a simple laboratory HGMF/S device; the matrix and its efficency; processing rates in HGMF/S; coal desulphurization and deashing - a potential application of HGMS. The paper concludes that HGMF/S is a process of high potential application as natural particles have a wide variation of magnetic character. Add to this the space saving nature of very powerful superconducting systems and their low energy consumption and it can be safely predicted that HGMF/S will, over time, gain many more applications as whole or part of whole filtration and separation processes. 19 references.

  8. Flocculation, hydrophobic agglomeration and filtration of ultrafine coal

    Science.gov (United States)

    Yu, Zhimin

    In coal preparation plant circuits, fine coal particles are aggregated either by oil agglomeration or by flocculation. In a new hydrophobic agglomeration process, recently developed hydrophobic latices are utilized. While the selectivity of such aggregation processes determines the beneficiation results, the degree of aggregation has a strong effect on fine coal filtration. The aim of this research was to study the fundamentals and analyze the common grounds for these processes, including the potential effect of the coal surface properties. The selective flocculation tests, in which three types of coal, which differed widely in surface wettability, and three additives (hydrophobic latices, a semi-hydrophobic flocculant and a typical hydrophilic polyelectrolyte) were utilized, showed that coal wettability plays a very important role in selective flocculation. The abstraction of a hydrophobic latex on coal and silica revealed that the latex had a much higher affinity towards hydrophobic coal than to hydrophilic mineral matter. As a result, the UBC-1 hydrophobic latex flocculated only hydrophobic coal particles while the polyelectrolyte (PAM) flocculated all the tested coal samples and minerals, showing no selectivity in the fine coal beneficiation. The oil agglomeration was tested using kerosene emulsified with various surfactants (e.g. cationic, anionic and non-ionic). Surfactants enhance not only oil emulsification, hence reducing oil consumption (down to 0.25--0.5%), but also entirely change the electrokinetic properties of the droplets and affect the interaction energy between oil droplets and coal particles. Consequently, the results found in the course of the experimental work strongly indicate that even oxidized coals can be agglomerated if cationic surfactants are used to emulsify the oil. Oil agglomeration of the Ford-4 ultrafine coal showed that even at extremely low oil consumption (0.25 to 0.5%), a clean coal product with an ash content around 5% at over

  9. Review series: The cell biology of renal filtration.

    Science.gov (United States)

    Scott, Rizaldy P; Quaggin, Susan E

    2015-04-27

    The function of the kidney, filtering blood and concentrating metabolic waste into urine, takes place in an intricate and functionally elegant structure called the renal glomerulus. Normal glomerular function retains circulating cells and valuable macromolecular components of plasma in blood, resulting in urine with just trace amounts of proteins. Endothelial cells of glomerular capillaries, the podocytes wrapped around them, and the fused extracellular matrix these cells form altogether comprise the glomerular filtration barrier, a dynamic and highly selective filter that sieves on the basis of molecular size and electrical charge. Current understanding of the structural organization and the cellular and molecular basis of renal filtration draws from studies of human glomerular diseases and animal models of glomerular dysfunction.

  10. 熔融结晶洗涤塔内过滤过程的研究%Study on Filtration Process of Molten Crystallization Washing Tower

    Institute of Scientific and Technical Information of China (English)

    李素娟; 肖剑; 宗弘元; 肖泽仪

    2011-01-01

    As for the filtration operation mode of molten crystallization washing tower,according to the surface filtration principle,the physical and mathematical models of the filtration were analyzed for the tower,and the differential equation and relevant boundary conditions were also established.Based on the solution of the differential equation,the expressions of pressure distribution and relationship between filtrate flow rate and cake thickness were deduced.This thesis show that filtrate volume flow rate in the washing tower had relation with pressure-drop,specific drainage pressure,filter medium resistance,cake thickness.According to those expressions,some factors affecting the filtration performance were also analyzed.These results revealed some structure features and operation principle of the washing tower to a certain extent.Furthermore,the mechanical squeezing behavior against the crystal bed,during being delivered upward by the screw peeler,and its effect on filtration and further liquid-removal were analyzed,and the calculation formula of filtrate volume flow rate under the combined action of the filtration and the mechanical squeezing were also deduced.%针对熔融结晶洗涤塔的过滤操作模式,根据表面过滤原理分析了洗涤塔内过滤段的物理模型和数学模型,建立了过滤微分方程和相关边界条件;通过过滤方程的求解,建立了过滤段滤饼过滤的压力分布公式以及滤液体积流率与滤饼变化厚度的关系式,并对相关主要影响因素进行了分析。结果表明,洗涤塔过滤段滤液体积流率与压力降、比滤阻、过滤介质阻力、滤饼厚度等有关,这个结果在一定程度上揭示了洗涤塔的部分结构和操作原理。又对结晶在向上输送过程中的机械压榨行为和母液进一步脱除的工作原理进行了分析计算,并推导出了过滤和压榨联合作用下的滤液体积流率的计算公式。

  11. Fast filtration for metabolome sampling of suspended animal cells

    OpenAIRE

    Volmer, Martin; Northoff, Stefan; Scholz, Sebastian; Thüte, Tobias; Büntemeyer, Heino; Noll, Thomas

    2010-01-01

    Abstract A new method for sampling suspended animal cells by fast filtration is presented that allows rapid quenching of cellular metabolism and efficient separation of the cells from culture medium. Compared to sampling with a microstructure heat exchanger or centrifugation without prior quenching, the adenylate energy charge and the measured concentrations especially of metabolites with a high turnover rate or of metabolites early in metabolic pathways were substantially higher. ...

  12. EFFECT OF KIESELGUHR FILTRATION ON OPTICAL PROPERTIES OF BEER

    OpenAIRE

    Helena Frančáková; Štefan Dráb; Miriam Solgajová; Žigmund Tóth; Tatiana Bojňanská

    2013-01-01

    Looks of beer is an important factor which is associated with high clarity. Clarity of beer is a basic precondition of its good marketability and consumer satisfaction. Beer filtration is ideal tool to create required optical properties. There is a high accent on this operation in brewery and minibrewery. The process of filtering removes unwanted haze-active substances in order to increase clarity and overall stability of beer. Objective method to expressing clarity of beer is nephelometric d...

  13. The Potentiometric Titration of Filtrates from the Bachmann Process

    Science.gov (United States)

    1942-06-23

    or above, the ferrous sulfato tost was negative anc: tho ph«holdl»ulfoBlc’ IfSt test indicated Less than 100 ppm., of niträte ion in the distillates...to Ü.5). 5. With the exception of two of the early runs, when the pH of the filtrate waa 2.0 or abovt- the ferrous sulfato test in the distillate

  14. Fast filtration for metabolome sampling of suspended animal cells

    OpenAIRE

    Volmer, Martin; Northoff, Stefan; Scholz, Sebastian; Thüte, Tobias; Büntemeyer, Heino; Noll, Thomas

    2010-01-01

    Abstract A new method for sampling suspended animal cells by fast filtration is presented that allows rapid quenching of cellular metabolism and efficient separation of the cells from culture medium. Compared to sampling with a microstructure heat exchanger or centrifugation without prior quenching, the adenylate energy charge and the measured concentrations especially of metabolites with a high turnover rate or of metabolites early in metabolic pathways were substantially higher. ...

  15. Rapid detection of simulated bacteremia by centrifugation and filtration.

    OpenAIRE

    Herlich, M B; Schell, R F; Francisco, M.; Le Frock, J L

    1982-01-01

    A centrifugation-filtration procedure was developed to expedite the recovery of microorganisms from blood. Fresh whole human blood was inoculated with various aerobic and facultatively anaerobic microorganisms (3 to 18 per ml). The seeded blood was carefully overlaid on a Ficoll-Hypaque gradient (density, 1.114 g/ml) and centrifuged (400 x g) for 45 min at ambient temperature. The entire gradient (plasma, leukocytes, and Ficoll-Hypaque) was removed and filtered through a 0.22-micrometer membr...

  16. Plasmapheresis and other extracorporeal filtration techniques in critical patients.

    Science.gov (United States)

    Daga Ruiz, D; Fonseca San Miguel, F; González de Molina, F J; Úbeda-Iglesias, A; Navas Pérez, A; Jannone Forés, R

    2017-04-01

    Plasmapheresis is an extracorporeal technique that eliminates macromolecules involved in pathological processes from plasma. A review is made of the technical aspects, main indications in critical care and potential complications of plasmapheresis, as well as of other extracorporeal filtration techniques such as endotoxin-removal columns and other devices designed to eliminate cytokines or modulate the inflammatory immune response in critical patients. Copyright © 2016 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  17. Benchtop isolation and characterization of functional exosomes by sequential filtration.

    Science.gov (United States)

    Heinemann, Mitja L; Ilmer, Matthias; Silva, Leslie P; Hawke, David H; Recio, Alejandro; Vorontsova, Maria A; Alt, Eckhard; Vykoukal, Jody

    2014-12-05

    Early and minimally invasive detection of malignant events or other pathologies is of utmost importance in the pursuit of improved patient care and outcomes. Recent evidence indicates that exosomes and extracellular vesicles in serum and body fluids can contain nucleic acid, protein, and other biomarkers. Accordingly, there is great interest in applying these clinically as prognostic, predictive, pharmacodynamic, and early detection indicators. Nevertheless, existing exosome isolation methods can be time-consuming, require specialized equipment, and/or present other inefficiencies regarding purity, reproducibility and assay cost. We have developed a straightforward, three-step protocol for exosome isolation of cell culture supernatants or large volumes of biofluid based on sequential steps of dead-end pre-filtration, tangential flow filtration (TFF), and low-pressure track-etched membrane filtration that we introduce here. Our approach yields exosome preparations of high purity and defined size distribution and facilitates depletion of free protein and other low-molecular-weight species, extracellular vesicles larger than 100nm, and cell debris. Samples of exosomes prepared using the approach were verified morphologically by nanoparticle tracking analysis and electron microscopy, and mass spectrometry analyses confirmed the presence of previously reported exosome-associated proteins. In addition to being easy-to-implement, sequential filtration yields exosomes of high purity and, importantly, functional integrity as a result of the relatively low-magnitude manipulation forces employed during isolation. This answers an unmet need for preparation of minimally manipulated exosomes for investigations into exosome function and basic biology. Further, the strategy is amenable to translation for clinical exosome isolations because of its speed, automatability, scalability, and specificity for isolating exosomes from complex biological samples.

  18. Intra-aortic filtration is effective in collecting hazardous materials.

    Science.gov (United States)

    Mestres, Carlos-A; Bernabeu, Eduardo; Fernández, Claudio; Colli, Andrea; Josa, Miguel

    2007-04-01

    Neurological complications after cardiac operations are mostly due to particle embolization. This case illustrates the embolic potential of any material. A 77-year-old lady underwent re-operation for homograft aortic regurgitation and mitral valve replacement. Intra-aortic filtration was used. After cardiopulmonary bypass the filter was found to have captured a pledget from a suture used to secure the mitral replacement device.

  19. Removal of benzocaine from water by filtration with activated carbon

    Science.gov (United States)

    Howe, G.E.; Bills, T.D.; Marking, L.L.

    1990-01-01

    Benzocaine is a promising candidate for registration with the U.S. Food and Drug Administration for use as an anesthetic in fish culture, management, and research. A method for the removal of benzocaine from hatchery effluents could speed registration of this drug by eliminating requirements for data on its residues, tolerances, detoxification, and environmental hazards. Carbon filtration effectively removes many organic compounds from water. This study tested the effectiveness of three types of activated carbon for removing benzocaine from water by column filtration under controlled laboratory conditions. An adsorptive capacity was calculated for each type of activated carbon. Filtrasorb 400 (12 x 40 mesh; U.S. standard sieve series) showed the greatest capacity for benzocaine adsorption (76.12 mg benzocaine/g carbon); Filtrasorb 300 (8 x 30 mesh) ranked next (31.93 mg/g); and Filtrasorb 816 (8 x 16 mesh) absorbed the least (1.0 mg/g). Increased adsorptive capacity was associated with smaller carbon particle size; however, smaller particle size also impeded column flow. Carbon filtration is a practical means for removing benzocaine from treated water.

  20. The filtration of colloidal gold nanoparticles with carbon nanotubes

    Science.gov (United States)

    de Jong, Frans Jan; Buffet, Adeline

    2016-11-01

    Understanding the local filtering of nanoparticles (NPs) is essential for the development and optimization of medical and industrial applications. Microfocus small-angle X-ray scattering (μSAXS) was used to determine the local filtration kinetics of 100 nm sized colloidal gold nanoparticles (Au NPs) within a multi-walled carbon nanotube (MWCNT) forest. To get a physical insight into the Au NP filtration process within the MWCNT forest a novel model based on the well-known DLVO theory was developed. The DLVO theory is commonly used to describe the interaction between colloidal particles. In addition to the attractive Van de Waals force and the electrostatic double-layer force, a non-DLVO force is added to account for hydration and hydrophobic effects. The model presented here shows that the Au NPs are mainly unfavorably deposited into the so-called secondary energy minimum. This latter finding is in good agreement with the experimental observations and the literature, in which unfavorable particle deposition is related to deposition into the secondary energy minimum. The use of μSAXS to get a physical insight into the local deposition kinetics of submicrometer particles opens up new pathways to optimize the preparation of MWCNT forests for filtration purposes.

  1. Modeling the filtration ability of stockpiled filtering facepiece

    Science.gov (United States)

    Rottach, Dana R.

    2016-03-01

    Filtering facepiece respirators (FFR) are often stockpiled for use during public health emergencies such as an infectious disease outbreak or pandemic. While many stockpile administrators are aware of shelf life limitations, environmental conditions can lead to premature degradation. Filtration performance of a set of FFR retrieved from a storage room with failed environmental controls was measured. Though within the expected shelf life, the filtration ability of several respirators was degraded, allowing twice the penetration of fresh samples. The traditional picture of small particle capture by fibrous filter media qualitatively separates the effect of inertial impaction, interception from the streamline, diffusion, settling, and electrostatic attraction. Most of these mechanisms depend upon stable conformational properties. However, common FFR rely on electrets to achieve their high performance, and over time heat and humidity can cause the electrostatic media to degrade. An extension of the Langevin model with correlations to classical filtration concepts will be presented. The new computational model will be used to predict the change in filter effectiveness as the filter media changes with time.

  2. Are vacuum-filtrated reduced graphene oxide membranes symmetric?

    KAUST Repository

    Tang, Bo

    2015-12-02

    Graphene or reduced graphene oxide (rGO) membrane-based materials are promising for many advanced applications due to their exceptional properties. One of the most widely used synthesis methods for rGO membranes is vacuum filtration of graphene oxide (GO) on a filter membrane, followed by reduction, which shows great advantages such as operational convenience and good controllability. Despite vacuum-filtrated rGO membranes being widely used in many applications, a fundamental question is overlooked: are the top and bottom surfaces of the membranes formed at the interfaces with air and with the filter membrane respectively symmetric or asymmetric? This work, for the first time, reports the asymmetry of the vacuum-filtrated rGO membranes and discloses the filter membranes’ physical imprint on the bottom surface of the rGO membrane, which takes place when the filter membrane surface pores have similar dimension to GO sheets. This result points out that the asymmetric surface properties should be cautiously taken into consideration while designing the surface-related applications for GO and rGO membranes.

  3. Virus removal vs. subsurface water velocity during slow sand filtration.

    Science.gov (United States)

    Dizer, Halim; Brackmann, Bernhard; Rahman, M Azizur; Szewzyk, Regine; Sprenger, Christoph; Holzbecher, Ekkehard; López-Pila, Juan M

    2015-06-01

    In an attempt to obtain a conservative estimate of virus removal during slow sand and river bank filtration, a somatic phage was isolated with slow decay and poor adsorption to coarse sand. We continuously fed a phage suspension to a 7-m infiltration path and measured the phage removal. In a second set of experiments, we fed the phage suspension to 1-m long columns run at different pore water velocities. Using the data obtained, a mathematical model was constructed describing removal vs. pore water velocity (PWV), assuming different statistical distributions of the adsorption coefficient λ. The bimodal distribution best fit the results for PWVs higher than 1 m/d. It predicted a removal of approximately 4 log10 after 50 days infiltration at 1 m/d. At PWVs below 1 m/d the model underestimated removal. Sand-bound phages dissociated slowly into the liquid phase, with a detachment constant kdet of 2.6 × 10⁻⁵. This low kdet suggests that river bank filtration plants should be intermittently operated when viral overload is suspected, e.g. during flooding events or at high water-marks in rivers, in order for viruses to become soil-associated during the periods of standstill. Resuming filtration will allow only a very slow virus release from the soil.

  4. Vulnerability of bank filtration systems to climate change.

    Science.gov (United States)

    Sprenger, C; Lorenzen, G; Hülshoff, I; Grützmacher, G; Ronghang, M; Pekdeger, A

    2011-01-15

    Bank filtration (BF) is a well established and proven natural water treatment technology, where surface water is infiltrated to an aquifer through river or lake banks. Improvement of water quality is achieved by a series of chemical, biological and physical processes during subsurface passage. This paper aims at identifying climate sensitive factors affecting bank filtration performance and assesses their relevance based on hypothetical 'drought' and 'flood' climate scenarios. The climate sensitive factors influencing water quantity and quality also have influence on substance removal parameters such as redox conditions and travel time. Droughts are found to promote anaerobic conditions during bank filtration passage, while flood events can drastically shorten travel time and cause breakthrough of pathogens, metals, suspended solids, DOC and organic micropollutants. The study revealed that only BF systems comprising an oxic to anoxic redox sequence ensure maximum removal efficiency. The storage capacity of the banks and availability of two source waters renders BF for drinking water supply less vulnerable than surface water or groundwater abstraction alone. Overall, BF is vulnerable to climate change although anthropogenic impacts are at least as important. Copyright © 2010 Elsevier B.V. All rights reserved.

  5. Filtration parameters influencing circulating tumor cell enrichment from whole blood.

    Directory of Open Access Journals (Sweden)

    Frank A W Coumans

    Full Text Available Filtration can achieve circulating tumor cell (CTC enrichment from blood. Key parameters such as flow-rate, applied pressure, and fixation, vary largely between assays and their influence is not well understood. Here, we used a filtration system, to monitor these parameters and determine their relationships. Whole blood, or its components, with and without spiked tumor cells were filtered through track-etched filters. We characterize cells passing through filter pores by their apparent viscosity; the viscosity of a fluid that would pass with the same flow. We measured a ratio of 5·10(4∶10(2∶1 for the apparent viscosities of 15 µm diameter MDA-231 cells, 10 µm white cells and 90 fl red cells passing through a 5 µm pore. Fixation increases the pressure needed to pass cells through 8 µm pores 25-fold and halves the recovery of spiked tumor cells. Filtration should be performed on unfixed samples at a pressure of ∼10 mbar for a 1 cm(2 track-etched filter with 5 µm pores. At this pressure MDA-231 cells move through the filter in 1 hour. If fixation is needed for sample preservation, a gentle fixative should be selected. The difference in apparent viscosity between CTC and blood cells is key in optimizing recovery of CTC.

  6. Active osmotic exchanger for advanced filtration at the nano scale

    Science.gov (United States)

    Marbach, Sophie; Bocquet, Lyderic

    2015-11-01

    One of the main functions of the kidney is to remove the waste products of an organism, mostly by excreting concentrated urea while reabsorbing water and other molecules. The human kidney is capable of recycling about 200 liters of water per day, at the relatively low cost of 0.5 kJ/L (standard dialysis requiring at least 150 kJ/L). Kidneys are constituted of millions of parallel filtration networks called nephrons. The nephrons of all mammalian kidneys present a specific loop geometry, the Loop of Henle, that is believed to play a key role in the urinary concentrating mechanism. One limb of the loop is permeable to water and the other contains sodium pumps that exchange with a common interstitium. In this work, we take inspiration from this osmotic exchanger design to propose new nanofiltration principles. We first establish simple analytical results to derive general operating principles, based on coupled water permeable pores and osmotic pumps. The best filtration geometry, in terms of power required for a given water recycling ratio, is comparable in many ways to the mammalian nephron. It is not only more efficient than traditional reverse osmosis systems, but can also work at much smaller pressures (of the order of the blood pressure, 0.13 bar, as compared to more than 30 bars for pressure-retarded osmosis systems). We anticipate that our proof of principle will be a starting point for the development of new filtration systems relying on the active osmotic exchanger principle.

  7. GPS Data Filtration Method for Drive Cycle Analysis Applications

    Energy Technology Data Exchange (ETDEWEB)

    Duran, A.; Earleywine, M.

    2013-02-01

    When employing GPS data acquisition systems to capture vehicle drive-cycle information, a number of errors often appear in the raw data samples, such as sudden signal loss, extraneous or outlying data points, speed drifting, and signal white noise, all of which limit the quality of field data for use in downstream applications. Unaddressed, these errors significantly impact the reliability of source data and limit the effectiveness of traditional drive-cycle analysis approaches and vehicle simulation software. Without reliable speed and time information, the validity of derived metrics for drive cycles, such as acceleration, power, and distance, become questionable. This study explores some of the common sources of error present in raw onboard GPS data and presents a detailed filtering process designed to correct for these issues. Test data from both light and medium/heavy duty applications are examined to illustrate the effectiveness of the proposed filtration process across the range of vehicle vocations. Graphical comparisons of raw and filtered cycles are presented, and statistical analyses are performed to determine the effects of the proposed filtration process on raw data. Finally, an evaluation of the overall benefits of data filtration on raw GPS data and present potential areas for continued research is presented.

  8. Ultra-filtration measurement using CT imaging technology

    Energy Technology Data Exchange (ETDEWEB)

    Lu Junfeng [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, No.2 Beiyitiao Street, Zhongguancun, Haidian District, Beijing, 100190 (China); Lu Wenqiang, E-mail: junfenglu@mail.ipc.ac.c [Graduate University of Chinese Academy of Sciences, No.19A Yuquan Road, Shijingshan District, Beijing, 100049 (China)

    2009-02-01

    As a functional unit in the hemodialysis process, dialyzer captured quite a few medical research interests since 1980s. In the design of dialyzer or in the ongoing hemodialysis process, to estimate the ultra-filtration amount of a dialyzer, the sideway loss of the running blood flow through hollow fibers or filtration channels should be measured. This further leads to the measurement of the blood flow inside the dialyzer. For this measurement, a non-invasive method is highly desired because of the high-dense bundled hollow fibers or packed channels inside the dialyzer. As non-invasive measurement tools, CT (Computed Tomography) technologies were widely used for tissue, bone, and cancerous clinical analyses etc .... Thus, in this paper, a CT system is adopted to predict the blood flow inside a hollow fiber dialyzer. In view of symmetric property of the hollow fiber dialyzer, the largest cutting plane that parallels to the cylindrical dialyzer was analyzed by the CT system dynamically. And then, a noninvasive image analysis method used to predict the ultra-filtration amount is proposed.

  9. Evaluation of hyperbaric filtration for fine coal dewatering. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Parekh, B.K. [Univ. of Kentucky, Lexington, KY (United States); Hogg, R. [Pennsylvania State Univ., University Park, PA (United States); Fonseca, A. [CONSOL Inc. (United States)

    1996-08-15

    The main objectives of the project were to investigate the fundamental aspects of particle-liquid interaction in fine coal dewatering, to conduct laboratory and pilot plant studies on the applicability of hyperbaric filter systems and to develop process conditions for dewatering of fine clean coal to less than 20% moisture. The program consisted of three phases, namely Phase 1 -- Model Development, Phase 2 -- Laboratory Studies, Phase 3 -- Pilot Plant Testing. The Pennsylvania State University led efforts in Phase 1, the University of Kentucky in Phase 2, and CONSOL Inc. in Phase 3 of the program. All three organizations were involved in all the three phases of the program. The Pennsylvania State University developed a theoretical model for hyperbaric filtration systems, whereas the University of Kentucky conducted experimental studies to investigate fundamental aspects of particle-liquid interaction and application of high pressure filter in fine coal dewatering. The optimum filtration conditions identified in Phase 1 and 2 were tested in two of the CONSOL Inc. coal preparation plants using an Andritz Ruthner portable hyperbaric filtration unit.

  10. Using the developed cross-flow filtration chip for collecting blood plasma under high flow rate condition and applying the immunoglobulin E detection

    Science.gov (United States)

    Yeh, Chia-Hsien; Hung, Chia-Wei; Wu, Chun-Han; Lin, Yu-Cheng

    2014-09-01

    This paper presents a cross-flow filtration chip for separating blood cells (white blood cells, red blood cells, and platelets) and obtaining blood plasma from human blood. Our strategy is to flow the sample solution in parallel to the membrane, which can generate a parallel shear stress to remove the clogging microparticles on the membrane, so the pure sample solution is obtained in the reservoir. The cross-flow filtration chip includes a cross-flow layer, a Ni-Pd alloy micro-porous membrane, and a reservoir layer. The three layers are packaged in a polymethylmethacrylate (PMMA) frame to create the cross-flow filtration chip. Various dilutions of the blood sample (original, 2 × , 3 × , 5 × , and 10×), pore sizes with different diameters (1 µm, 2 µm, 4 µm, 7 µm, and 10 µm), and different flow rates (1 mL/min, 3 mL/min, 5 mL/min, 7 mL/min, and 10 mL/min) are tested to determine their effects on filtration percentage. The best filtration percentage is 96.2% when the dilution of the blood sample is 10 × , the diameter of pore size of a Ni-Pd alloy micro-porous membrane is 2 µm, and the flow rate is 10 mL/min. Finally, for the clinical tests of the immunoglobulin E (IgE) concentration, the cross-flow filtration chip is used to filter the blood of the allergy patients to obtain the blood plasma. This filtered blood plasma is compared with that obtained using the conventional centrifugation based on the enzyme-linked immunosorbent assay. The results reveal that these two blood separation methods have similar detection trends. The proposed filtration chip has the advantages of low cost, short filtration time, and easy operation and thus can be applied to the separation of microparticles, cells, bacteria, and blood.

  11. [Evaluation of preoperative anxiety in patients requiring glaucoma filtration surgery].

    Science.gov (United States)

    Lemaitre, S; Blumen-Ohana, E; Akesbi, J; Laplace, O; Nordmann, J-P

    2014-01-01

    Preoperative anxiety is often expressed by patients requiring filtration surgery for their glaucoma. So far, there has been no scale for screening this group of patients for preoperative anxiety. The Amsterdam Preoperative Anxiety and Information Scale (APAIS) is a self-evaluation questionnaire which has been used in specialties other than ophthalmology and which makes it possible to identify the adult patients with a high level of preoperative anxiety over an upcoming surgical procedure. The purpose of this study is to estimate the preoperative anxiety in glaucoma patients requiring filtration surgery. We performed a prospective study of 36 adult patients with chronic glaucoma not responding to medical treatment and who were about to undergo filtration surgery (trabeculectomy or deep sclerectomy). The APAIS questionnaire was given to the patients after discussing the indication for surgery. A global anxiety score (ranging from 4 to 20) above 10 defined patients with a high level of preoperative anxiety. We attempted to identify among these patients the factors related to filtration surgery which caused them anxiety (lack of control of intraocular pressure, risk of blindness, presence of the filtering bleb). In our sample of patients, we found that glaucoma was a source of anxiety. That was also true for the surgical procedure, though most patients believe that once the decision had been made, their psychological status was not modified by the upcoming procedure. The patient-clinician relationship is important in any chronic disease, all the more so in glaucoma, since this disease remains asymptomatic for a long time. When filtration surgery is necessary, the patients are going to express less preoperative anxiety if they trust their physician and if individualized information has been given to them The French version of the APAIS is a quick scale, easily completed, that can be recommended for evaluating anxiety and patients' need for information prior to filtering

  12. Preliminary evaluation of fungicidal and termiticidal activities of filtrates from biomass slurry fuel production.

    Science.gov (United States)

    Kartal, S N; Imamura, Y; Tsuchiya, F; Ohsato, K

    2004-10-01

    Biomass slurry fuel (BSF) production has recently been developed as a natural energy for the conversion of solid biomass into fuel. In addition to using fuel, filtrates from BSF production may also serve a chemical source with several organic compounds. There is an increasing interest in the research and application of biomass-based filtrates. In this study, fungicidal and termiticidal properties of filtrates from BSF production using sugi (Cryptomeria japonica) and acacia (Acacia mangium) wood were evaluated in laboratory decay and termite resistance tests. Wood blocks treated with the filtrates showed increased resistance against brown-rot fungus, Fomitopsis palustris. However the filtrates from sugi wood processed at 270 degrees C which contained less phenolic compounds than the other filtrates were effective against white-rot fungus, Trametes versicolor. Phenolic compounds of filtrates seemed to play a role in the decay resistance tests however the filtrates did not increase the durability of the wood blocks against subterranean termites Coptotermes formosanus. Despite high acetic and lactic acid content of the filtrates, vanillin content of the filtrates may have served as an additional food source and promoted termite attack. It can be concluded that filtrates with phenolic compounds from lignin degradation during BSF production can be considered for targeted inhibition of brown-rot.

  13. Preliminary evaluation of fungicidal and termiticidal activities of filtrates from biomass slurry fuel production

    Energy Technology Data Exchange (ETDEWEB)

    Kartal, S.N. [Istanbul University (Turkey). Forestry Faculty; Imamura, Y. [Kyoto University (Japan). Wood Research Institute; Tsuchiya, F.; Ohsato, K. [JGC Corporation, Yokohama (Japan)

    2004-10-01

    Biomass slurry fuel (BSF) production has recently been developed as a natural energy for the conversion of solid biomass into fuel. In addition to using fuel, filtrates from BSF production may also serve a chemical source with several organic compounds. There is an increasing interest in the research and application of biomass-based filtrates. In this study, fungicidal and termiticidal properties of filtrates from BSF production using sugi (Cryptomeria japonica) and acacia (Acacia mangium) wood were evaluated in laboratory decay and termite resistance tests. Wood blocks treated with the filtrates showed increased resistance against brown-rot fungus, Formitopsis palustris. However the filtrates from sugi wood processed at 270{sup o}C which contained less phenolic compounds than the other filtrates were effective against white-rot fungus, Trametes versicolor. Phenolic compounds of filtrates seemed to play a role in the decay resistance tests however the filtrates did not increase the durability of the wood blocks against subterranean termites Coptotermes formosanus. Despite high acetic and lactic acid content of the filtrates, vanillin content of the filtrates may have served as an additional food source and promoted termite attack. It can be concluded that filtrates with phenolic compounds from lignin degradation during BSF production can be considered for targeted inhibition of brown-rot. (author)

  14. Experimental Study on the Influence of DPF Micropore Structure and Particle Property on Its Filtration Process

    Directory of Open Access Journals (Sweden)

    Zhongwei Meng

    2016-01-01

    Full Text Available A single layer filtration system was developed to investigate the filtration and regeneration performance of diesel particle filter (DPF. The particle layer thickness was directly measured online to analyze the different filtration stages. The influence of particle property on particle layer stage performance was also investigated. The results indicate that the filtration velocity can greatly affect the deep bed filtration stage, and the deposited particle layer can be compressed even in very low filtration velocity and higher filtration velocity trends to form denser particle layer. Optimizing the pore structure can effectively shorten the deep bed filtration stage and reduce the pressure drop eventually. An empirical function was proposed to relate the pore structure and the initial increment rate of pressure drop, which presented that reducing the pore size distribution range (3σ can result in low DPF filtration pressure drop. The filtration stage could be further divided into four stages, and the value of particle layer thickness ranging within 15~20 μm has been found to be critical number for the shift from the transient stage to the cake filtration stage. Particle with large primary diameter and BET surface was beneficial to form loose particle layer.

  15. Fast filtration sampling protocol for mammalian suspension cells tailored for phosphometabolome profiling by capillary ion chromatography - tandem mass spectrometry.

    Science.gov (United States)

    Kvitvang, Hans F N; Bruheim, Per

    2015-08-15

    Capillary ion chromatography (capIC) is the premium separation technology for low molecular phosphometabolites and nucleotides in biological extracts. Removal of excessive amounts of salt during sample preparation stages is a prerequisite to enable high quality capIC separation in combination with reproducible and sensitive MS detection. Existing sampling protocols for mammalian cells used for GC-MS and LC-MS metabolic profiling can therefore not be directly applied to capIC separations. Here, the development of a fast filtration sampling protocol for mammalian suspension cells tailored for quantitative profiling of the phosphometabolome on capIC-MS/MS is presented. The whole procedure from sampling the culture to transfer of filter to quenching and extraction solution takes less than 10s. To prevent leakage it is critical that a low vacuum pressure is applied, and satisfactorily reproducibility was only obtained by usage of a vacuum pressure controlling device. A vacuum of 60mbar was optimal for filtration of multiple myeloma Jjn-3 cell cultures through 5μm polyvinylidene (PVDF) filters. A quick deionized water (DI-water) rinse step prior to extraction was tested, and significantly higher metabolite yields were obtained during capIC-MS/MS analyses in this extract compared to extracts prepared by saline and reduced saline (25%) washing steps only. In addition, chromatographic performance was dramatically improved. Thus, it was verified that a quick DI-water rinse is tolerated by the cells and can be included as the final stage during filtration. Over 30 metabolites were quantitated in JJN-3 cell extracts by using the optimized sampling protocol with subsequent capIC-MS/MS analysis, and up to 2 million cells can be used in a single filtration step for the chosen filter and vacuum pressure. The technical set-up is also highly advantageous for microbial metabolome filtration protocols after optimization of vacuum pressure and washing solutions, and the reduced salt

  16. A Study on Enhancement of Filtration Process with Filter Aids Diatomaceous Earth and Wood Pulp Cellulose

    Institute of Scientific and Technical Information of China (English)

    都丽红; 陈旭; 李文苹; 朱企新

    2011-01-01

    In this paper, a study to enhance the filtration for solid/liquid materials difficult to be filtered, such as highly viscous, highly compactible or gel like materials, is presented. Filter aids diatomaceous earth and wood pulp cellulose are used to enhance the filtration by improving filter cake structure and properties in the filtration of a biological health product and a highly viscous chemical fiber polymer melt product. The property of solid/liquidsystems, filtration at different flow rates, specitic cake resistance, cake wetness, filtration rate, filtrate turbidity for filter aid selection and evaluation, and operation optimization are investigated. The results are successfully applied to industrial process, .and can be used as a reference for similar filtration applications.

  17. Low-density lipoprotein apheresis by membrane differential filtration (cascade filtration) via arteriovenous fistula performed in children with familial hypercholesterolemia.

    Science.gov (United States)

    Gülle, Saniye; Bak, Mustafa; Serdaroglu, Erkin; Can, Demet; Karabay, Ozalp

    2010-02-01

    Membrane differential filtration (cascade filtration) is an apheresis technique by which atherogenic lipoproteins can be eliminated from plasma on the basis of particle size. In this study, we aim to discuss the efficacy of low-density lipoprotein (LDL) apheresis performed by providing alternative vascular routes in two siblings with familial hypercholesterolemia who did not respond to medical treatment and diet. Of the two siblings, one was nine years old and the other one was three-and-a-half years old. Of the total of 78 apheresis processes performed, 24 were done via a permanent subclavian catheter, 36 were done via a subsequently provided arteriovenous fistula, and 18 were done via an arteriovenous graft. We observed a mean reduction in the plasma levels of total cholesterol (61.6%), LDL cholesterol (65.5%), and high-density lipoprotein cholesterol (38.6%). We noted that cascade filtration apheresis was effective in decreasing the LDL cholesterol in plasma, and no serious complications were noted. The success of the apheresis program depends on well-functioning blood access. An arteriovenous fistula may be the best route for the long-term treatment of familial hypercholesterolemia, which requires complication-free apheresis treatments.

  18. Forward osmosis filtration for removal of organic foulants: Effects of combined tannic and alginic acids.

    Science.gov (United States)

    Wang, Lin; Zhang, Wanzhu; Chu, Huaqiang; Dong, Bingzhi

    2016-03-15

    The filtration performance of combined organic foulants by forward osmosis (FO) in active-layer-facing-the-draw-solution (AL-facing-DS) orientation was investigated systematically. Tannic acid and alginate were used as model organic foulants for polysaccharides and humic dissolved organic matters, respectively. The FO could reject combined and single tannic acid and alginate foulants effectively. The more severe fouling flux decline, accompanied with lower combined foulants' retention, was observed with increasing proportions of tannic acid in the combined foulants-containing feed, which was ascribed mainly to the more severe fouling resulting from tannic acid adsorption within the porous support layer of the FO membrane compared to minor alginate deposition on the membrane surface. It was found that the higher the initial flux level and cross flow velocity, the faster the flux decline with lower mixed foulants retention. It was also revealed that the calcium ions in a basic solution enhanced the combined fouling flux reduction and combined foulants retention. As the major constituent of the combined fouling layer, the adsorption of tannic acid might play a more significant role in the mixed fouling of the FO membrane, which was probably influenced by permeation drag caused by water flux and chemical interactions induced by feed solution pH and calcium ion concentration.

  19. 5f-electronic states of neptunium compounds: NpGe{sub 3}, NpRhGa{sub 5} and NpCd{sub 11}

    Energy Technology Data Exchange (ETDEWEB)

    Onuki, Y; Yoshiuchi, S; Settai, R [Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Aoki, D; Homma, Y; Shiokawa, Y [Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Haga, Y; Sakai, H; Ikeda, S; Yamamoto, E; Nakamura, A [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Takeuchi, T [Low Temperature Center, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Yamagami, H, E-mail: onuki@phys.sci.osaka-u.ac.jp [Department of Physics, Faculty of Science, Kyoto Sangyo University, Kyoto 603-8555 (Japan)

    2010-03-15

    We studied the electronic states of three typical neptunium compounds, NpGe{sub 3}, NpRhGa{sub 5} and NpCd{sub 11}. Among them, NpGe{sub 3} and NpCd{sub 11} with the cubic crystal structure are paramagnets without magnetic ordering, while NpRhGa{sub 5} with the tetragonal structure is an antiferromagnet. At high temperatures, the 5f electrons in NpGe{sub 3} are almost localized, and the magnetic susceptibility {chi}(T) approximately follows the Curie-Weiss law. With decreasing temperature, {chi}(T) shows a broad peak around 50 K, indicating a moderate heavy fermion state at lower temperatures. In fact, the results of the de Haas-van Alphen (dHvA) experiments for NpGe{sub 3} are well explained by the 5f-itinerant band model; namely, the 5f electrons contribute to the Fermi surface and the cyclotron effective mass. The cyclotron mass is thus enhanced, ranging from 2.6 to 16 times the rest mass of the electron m{sub 0}. In the antiferromagnet NpRhGa{sub 5}, it was clarified from the results of dHvA experiments and energy band calculations that the 5f electrons contribute to the Fermi surface. The cyclotron mass varies from 8.1 to 11.7 m{sub 0}, and the magnetic moment is 0.89 {mu}{sub B}/Np. In NpCd{sub 11}, the 5f electrons are localized in the whole temperature range and do not contribute to the Fermi surface. The corresponding cyclotron mass is thus light, below 1 m{sub 0}, revealing no hybridization between the localized 5f electrons and the conduction electrons. The Fermi surface consists of small closed Fermi surfaces, reflecting the small Brillouin zone associated to the large unit cell of the crystal structure in NpCd{sub 11}. The long Np-Np nearest-neighbor distance (6.568 A) results in the well localized 5f {sup 4}states. Magnetic susceptibility and magnetization curves are well explained in a crystalline electric field (CEF) scheme assuming a singlet ground state and an excited triplet state separated by a 120 K energy gap.

  20. Asymptotic approximation of long-time solution for low-temperature filtration combustion

    NARCIS (Netherlands)

    Chapiro, G.; Mallybaev, A.A.; De Souza, A.J.; Marchesin, D.; Bruining, J.

    2012-01-01

    There is a renewed interest in using combustion for the recovery of medium viscosity oil. We consider the combustion process when air is injected into the porous medium containing some fuel and inert gas. Commonly the reaction rate is negligible at low temperatures, hence the possibility of oxygen b

  1. Measurement of peptide-MHC interactions in solution using the spin column filtration assay

    DEFF Research Database (Denmark)

    Buus, Soren; Lise Lauemøller, S; Stryhn, A

    2001-01-01

    This unit describes how peptide-MHC complexes can be generated in vitro using affinity-purified MHC and synthetic peptide. The unit first describes how the interaction between peptide and MHC interaction can be measured in an accurate, quantitative biochemical assay. This procedure has been...... optimized for efficient separation of free peptide and MHC-bound peptide through a novel principle, termed "gradient centrifugation." The first two support protocols describe how to set up a biochemical fluid-phase binding reaction between peptide and MHC class I and class II, respectively. Also...

  2. Tetrapositive plutonium, neptunium, uranium, and thorium coordination complexes: chemistry revealed by electron transfer and collision induced dissociation.

    Science.gov (United States)

    Gong, Yu; Tian, Guoxin; Rao, Linfeng; Gibson, John K

    2014-04-17

    The Pu(4+), Np(4+), and U(4+) ions, which have large electron affinities of ∼34.6, ∼33.6, and ∼32.6 eV, respectively, were stabilized from solution to the gas phase upon coordination by three neutral tetramethyl-3-oxa-glutaramide ligands (TMOGA). Both collision induced dissociation (CID) and electron transfer dissociation (ETD) of Pu(TMOGA)3(4+) reveal the propensity for reduction of Pu(IV) to Pu(III), by loss of TMOGA(+) in CID and by simple electron transfer in ETD. The reduction of Pu(IV) is in distinct contrast to retention of Th(IV) in both CID and ETD of Th(TMOGA)3(4+), where only the C-Oether bond cleavage product was observed. U(TMOGA)3(4+) behaves similarly to Th(TMOGA)3(4+) upon CID and ETD, while the fragmentation patterns of Np(TMOGA)3(4+) lie between those of Pu(TMOGA)3(4+) and U(TMOGA)3(4+). It is notable that the gas-phase fragmentation behaviors of these exceptional tetrapositive complexes parallel fundamental differences in condensed phase chemistry within the actinide series, specifically the tendency for reduction from the IV to III oxidation states.

  3. Pole solutions for flame front propagation

    CERN Document Server

    Kupervasser, Oleg

    2015-01-01

    This book deals with solving mathematically the unsteady flame propagation equations. New original mathematical methods for solving complex non-linear equations and investigating their properties are presented. Pole solutions for flame front propagation are developed. Premixed flames and filtration combustion have remarkable properties: the complex nonlinear integro-differential equations for these problems have exact analytical solutions described by the motion of poles in a complex plane. Instead of complex equations, a finite set of ordinary differential equations is applied. These solutions help to investigate analytically and numerically properties of the flame front propagation equations.

  4. DEMONSTRATION OF THE DWPF FLOWSHEET IN THE SRNL SHIELDED CELLS WITH TANK 40 AND H CANYON NEPTUNIUM

    Energy Technology Data Exchange (ETDEWEB)

    Pareizs, J; Bradley Pickenheim, B; Cj Bannochie, C; Michael Stone, M

    2009-04-28

    The Defense Waste Processing Facility (DWPF) is currently processing Sludge Batch 5 (SB5) from Tank 40. SB5 contains the contents of Tank 51 from November 2008, qualified by the Savannah River National Laboratory (SRNL) and the heel in Tank 40 remaining from Sludge Batch 4. Current Liquid Waste Operations (LWO) plans are to (1) decant supernatant from Tank 40 to remove excess liquid caused by a leaking slurry pump and (2) receive a Np stream from H Canyon It should be noted that the Np stream contains significant nitrate requiring addition of nitrite to Tank 40 to maintain a high nitrite to nitrate ratio for corrosion control. SRNL has been requested to qualify the proposed changes; determine the impact on DWPF processability in terms of hydrogen generation, rheology, etc.; evaluate antifoam addition strategy; and evaluate mercury stripping. Therefore, SRNL received a 3 L sample of Tank 40 following the transfer of Tank 51 to Tank 40 (Tank Farm Sample HTF-40-08-157 to be used in testing and to perform the required Waste Acceptance Product Specifications radionuclide analyses). Based on Tank Farm projections, SRNL decanted a portion* of the sample, added sodium nitrite, and added a Np solution from H Canyon representative of the Np to be dispositioned to Tank 40 (neutralized to 0.6 M excess hydroxide). The resulting material was used in a DWPF Chemical Process Cell (CPC) demonstration -- a Sludge Receipt and Adjustment Tank (SRAT) cycle and a Slurry Mix Evaporator (SME) cycle. Preliminary data from the demonstration has been reported previously. This report includes discussion of these results and additional results, including comparisons to Tank Farm projections and the SB5 demonstration.

  5. Subconjunctival sustained release 5-fluorouracil for glaucoma filtration surgery

    Institute of Scientific and Technical Information of China (English)

    Li-jun CUI; Nai-xue SUN; Xing-hua LI; Jie HUANG; Jian-gang YANG

    2008-01-01

    Aim:To determine the release characteristics of a 5-fluorouracil-loaded poly (lactic acid) disc (5-FU-PLA-DS) and the effect of sustained drug delivery on the success of glaucoma filtration surgery in rabbit eyes. Methods: A method of microspheres accumulated by excessive carriers was used in the preparation of the 5-FU-PLA-DS. The disc was characterized for drug loading, entrapment efficiency, in vitro release, and external morphology. It was then implanted sub-conjunctivally into rabbit eyes with trabeculectomy. Intraocular pressure, ocular inflammatory reaction, filtration bleb appearance, and persistence were evalu-ated up to postoperative d 90. A quantitative analysis of 5-fluorouracil (5-FU) was performed in the aqueous humor. Ultrasound biomicroscopy was used to assess the appearance of the filtering fistula. Results: The 5-FU-PLA-DS was produced with the drug-loading of 3.07±0.08 mg (mean±SD). 5-FU was released for 91 d with suppressive concentrations. The decrease in intraocular pressure from baseline was significantly more marked in the 5-FU-PLA-DS-implanted eyes during postoperative d 3-90, and the persistence of bleb and filtration fistula was longer than the control eyes (P<0.05). Corneal toxicity and hyperemia triggered by 5-FU was lower in the 5-FU-PLA-DS-implanted eyes than those exposed to 5-FU intraoperatively. The 5-FU concentration in the aqueous humor was insufficient for corneal endothelial damage. No evidence of toxic reaction was found in the conjunctival biopsy. Conclusion: 5-FU-PLA-DS displaying sustained intraocular release of 5-FU, reduced intraocular pres-sure, and prolonged bleb persistence, while significantly reducing 5-FU toxicity.

  6. Feasibility Analysis of a Seabed Filtration Intake System for the Shoaiba III Expansion Reverse Osmosis Plant

    KAUST Repository

    Rodríguez, Luis Raúl

    2012-06-01

    The ability to economically desalinate seawater in arid regions of the world has become a vital advancement to overcome the problem on freshwater availability, quality, and reliability. In contrast with the major capital and operational costs for desalination plants represented by conventional open ocean intakes, subsurface intakes allow the extraction of high quality feed water at minimum costs and reduced environmental impact. A seabed filter is a subsurface intake that consists of a submerged slow sand filter, with benefits of organic matter removal and pathogens, and low operational cost. A site investigation was carried out through the southern coast of the Red Sea in Saudi Arabia, from King Abdullah University of Science and Technology down to 370 kilometers south of Jeddah. A site adjacent to the Shoaiba desalination plant was selected to assess the viability of constructing a seabed filter. Grain sieve size analysis, porosity and hydraulic conductivity permeameter measurements were performed on the collected sediment samples. Based on these results, it was concluded that the characteristics at the Shoaiba site allow for the construction of a seabed filtration system. A seabed filter design is proposed for the 150,000 m3/d Shoaiba III expansion project, a large-scale Reverse Osmosis desalination plant. A filter design with a filtration rate of 7 m/d through an area of 6,000 m2 is proposed to meet the demand of one of the ten desalination trains operating at the plant. The filter would be located 90 meters offshore where hydraulic conductivity of the sediment is high, and mud percentage is minimal. The thin native marine sediment layer is insufficient to provide enough water filtration, and consequently the proposed solution involves excavating the limestone rock and filling it with different layers of non-native sand and gravel of increasing grain size. An initial assessment of the area around Shoaiba showed similar sedimentological conditions that could

  7. Improved Filtration Technology for Pathogen Reduction in Rural Water Supplies

    Directory of Open Access Journals (Sweden)

    Valentine Tellen

    2010-06-01

    Full Text Available Intermittent bio-sand filtration (BSF is a low-cost process for improving water quality in rural households. This study addresses its two drawbacks: flow limitations requiring excessive waiting, and inadequate purification when high flows are imposed. Two modifications were examined: increasing the sand’s effective size, and adding zero-valent iron (ZVI into the media as a disinfectant. After 65 days, percent reductions in total coliform, fecal coliform, and fecal streptococci averaged 98.9% for traditional BSF and 99% for the improved BSF. Both modifications showed statistically significant improvements. Increased sand size and ZVI addition can counter the drawbacks of traditional BSF.

  8. Indexing Glomerular Filtration Rate to Body Surface Area

    DEFF Research Database (Denmark)

    Redal-Baigorri, Belén; Rasmussen, Knud; Heaf, James Goya

    2014-01-01

    BACKGROUND: Kidney function is mostly expressed in terms of glomerular filtration rate (GFR). A common feature is the expression as ml/min per 1.73 m(2) , which represents the adjustment of the individual kidney function to a standard body surface area (BSA) to allow comparison between individuals....... We investigated the impact of indexing GFR to BSA in cancer patients, as this BSA indexation might affect the reported individual kidney function. METHODS: Cross-sectional study of 895 adults who had their kidney function measured with (51) chrome ethylene diamine tetraacetic acid. Mean values of BSA...

  9. High gradient magnetic filtration and separation. Part 1

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, D.

    1986-12-01

    This paper reviews the developing role of high gradient magnetic filtration (HGMF), and separation (HGMS). If discusses the relative position of this technique within the context of the general field of magnetic separation. Its future potential and the basic theory behind it is also reviewed. The two processes; HGMF and HGMS are well known and well established fuels used frequently in mineral processing, for example iron ore. Using different techniques and machines a whole host of uses is possible and the paper concludes by outlining the theory behind this whole area. 11 refs.

  10. Particulate filtration for sorbent-based H2 storage

    Science.gov (United States)

    van Hassel, Bart A.; Karra, Jagadeswara R.

    2016-01-01

    A method was developed for sizing the particulate filter that can be used inside a sorption-based onboard hydrogen storage system for light-duty vehicles. The method is based on a trade-off between the pressure drop across the particulate filter (during the fill of the H2 storage tank or during its discharge while driving) and the effect of this pressure drop on the usable amount of H2 gas from the H2 storage system. The permeability and filtration efficiency of the particulate filters (in the absence and presence of MOF-5 particulates) was quantified in this study, with an emphasis on meeting DOE's H2 purity requirements.

  11. Non-steady-state aerosol filtration in nanostructured fibrous media.

    Science.gov (United States)

    Przekop, Rafal; Gradoń, Leon

    2011-06-28

    The filtration of aerosol particles using composites of nano- and microsized fibrous structures is a promising method for the effective separation of nanoparticles from gases. A multi-scale physical system describing the flow pattern and particle deposition at a non-steady-state condition requires an advanced method of modelling. The combination of lattice Boltzmann and Brownian dynamics was used for analysis of the particle deposition pattern in a fibrous system. The dendritic structures of deposits for neutral and charged fibres and particles are present. The efficiency of deposition, deposit morphology, porosity and fractal dimension were calculated for a selected operational condition of the process.

  12. Possibilities for the filtration of inlet air for gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Sievert, J.; Reinhardt, H.

    1988-05-01

    Gas turbines require large quantities of air, which are sucked in from the atmosphere. Depending on the weather conditions and the location of the gas turbine the ambient air contains impurities which may lead to damage to or contamination of the blading of the compressors and turbines. In consequence this causes a reduction in output or efficiency. In principle there are several possibilities for the filtration of air sucked in for gas turbines of which the technically relevant ones at the present time are described.

  13. Filtration in ultrasonic field; Filtracao em campo ultrassonico

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Inaura Carolina C. da; Cortes, Marcela de Araujo H.; Marques, Jose Jailton [Universidade Federal de Sergipe (UFS), Aracaju, SE (Brazil). Dept. de Engenharia Quimica

    2008-07-01

    The production of water associated to the petroleum is an issue of big relevance in exploration areas classified as 'exhausted fields'. The current alternative in practice is the re-injection of the wastewater into the geological formation with the dual purpose of increasing oil recovery and pollution minimization. However, produced water presents several components that make impossible its direct re-injection, requiring a previous treatment. In this context, this work presents the state-of-art of filtration in ultrasonic field, in order to contribute to the development of a new treatment technology applicable to the produced water problem. (author)

  14. How can liver toxins be removed? Filtration and adsorption with the Prometheus system.

    Science.gov (United States)

    Vienken, Joerg; Christmann, Horst

    2006-04-01

    The application of extracorporeal blood circuits in liver failure therapy has its roots in the two functions of the liver, first as a detoxifying and second as a synthetizing organ. In contrast to hydrophilic uremic toxins, most liver toxins are hydrophobic and bind preferentially to blood proteins. Consequently, the majority of these compounds cannot be removed by hemodialysis or similar dialytic procedures. Current systems use albumin as a transport vehicle for hydrophobic compounds across high flux membranes (e.g. albumin-dialysis, molecular adsorbent recirculating system (MARS)). In contrast to these devices, the Prometheus system (Fresenius Medical Care, Bad Homburg, Germany) applies filtration across highly permeable membranes with a molecular weight cut-off of >300.000. These membranes facilitate a direct filtration of most of the toxin-bearing proteins. In a secondary circuit these toxins are then removed by adsorber beads assembled in specially designed cartridges. The protein-containing toxin-free solution returns to the primary circuit. Clinical testing of the Prometheus system's safety and efficacy parameters showed that cell counts and coagulation factors were not significantly affected. Total bilirubin-, bile acid- and plasma ammonia-levels were reduced in vivo by -21%, -43% and -40%, respectively. First successful therapeutic results have been obtained for patients treated for drug abuse and for patients waiting for transplantation. Thus, a combination of plasma fractionation with highly permeable membranes followed by a secondary circuit with adsorber cartridges proves to be the most effective method of removing toxic waste in liver failure. Further investigations will follow in order to extend the application of the Prometheus system to larger cohorts of patients.

  15. Survey of Nano filtration Performance for Hexavalent Chromium Removal fromWater Containing Sulfate

    Directory of Open Access Journals (Sweden)

    Gh.R Moussavi

    2010-10-01

    Full Text Available "n "n "nBackgrounds and Objectives: Geological situation and/or anthropogenic contamination contain an increased concentration of ions such as hexavalent chromium as well as some other dissolved components such as sulfate in the upper of the establishedMCLs (50µg/L. In this paper, simultaneous removal of Cr (VI and sulfate from water was investigated using nanofiltration as a promising method for reaching drinking water standards."nMaterials and Methods: For varying pressure, pH , anion and cation solution effect, Sulfate and Cr (VI concentration which have chosen were levels found in drinking water sources (Cr=0.1- 0.5mg/L and (SO4-2= 100-800mg/L.Experiments were performed using NaCl, Na2SO4,K2 Cr2O7and anhydrous CrCl3. 6H2O which prepared with de mineralized water on procedure detailed in standard methods. All salts were purchased from Merck Corporation with purity over 99'."nResults: The results for hexavalent chromium experiments showed that when the concentration decreases, the chromate anions were given a better retention to 4 bars (96'. But when the concentration increases, concentration polarization led to increased removal of Cr (VI (98'. For Cr (III the influences of the ionic strength as well as the concentrations were strongly dependant on rejection but operating pressure were found weak. In addition, with increasing total dissolved solids, perfect rejection of chromium was seen. The effect of pH showed that better retention was obtained at natural and basic pH."nConclusion: This study indicates that the nature of anions and cations, driven pressure and pH have significant effect on nano filtration operation. Research findings show that it seems nano filtration is a very good promising method of simultaneous removal of Cr (VI and sulfate from water.

  16. On a free boundary problem for a strongly degenerate quasilinear parabolic equation with an application to a model of pressure filtration

    Energy Technology Data Exchange (ETDEWEB)

    Buerger, R.; Frid, H.; Karlsen, K.H.

    2002-07-01

    We consider a free boundary problem of a quasilinear strongly degenerate parabolic equation arising from a model of pressure filtration of flocculated suspensions. We provide definitions of generalized solutions of the free boundary problem in the framework of L2 divergence-measure fields. The formulation of boundary conditions is based on a Gauss-Green theorem for divergence-measure fields on bounded domains with Lipschitz deformable boundaries and avoids referring to traces of the solution. This allows to consider generalized solutions from a larger class than BV. Thus it is not necessary to derive the usual uniform estimates on spatial and time derivatives of the solutions of the corresponding regularized problem requires in the BV approach. We first prove existence and uniqueness of the solution of the regularized parabolic free boundary problem and then apply the vanishing viscosity method to prove existence of a generalized solution to the degenerate free boundary problem. (author)

  17. Study on Filtration Performance of Silica/Alumina Slurry in the Process of Recycling Mother Liquor of NaY Zeolite

    Institute of Scientific and Technical Information of China (English)

    Guo Yaoqing; Ma Yuelong; Deng Jinghui

    2004-01-01

    In order to recover the SiO2 contained in the mother liquor in the course of NaY zeolite synthesis to minimize pollution, the influence of various preparation conditions on the filtering velocity of gel slurry was studied using the SiO2/Al2O3 gel recovered from the NaY mother liquor in the laboratory. The results of study had shown that at a SiO2/A12O3 ratio in the feed equating to 9:1 the SiO2 recovery rate and Al2O3utilization rate were high with a faster flow velocity of the filtrate. The pH value of the system had great impact on the flow velocity of filtrate. Between the two methods for regulating the pH value, the one for formation of silica/alumina gel slurry by addition of sulfuric acid prior to adding aluminium sulfate in the solution could secure a faster filtration velocity. The filtration velocity was decreased in tandem with increasing SiO2 concentration in mother liquor, meanwhile an increase in dry filter cake yield.

  18. Dedicated breast CT: effect of adaptive filtration on dose distribution

    CERN Document Server

    Shikhaliev, Polad M

    2016-01-01

    Purpose: The purpose of the work was experimental investigations of the breast dose distributions with adaptive filtration. Adaptive filtration reduces detector dynamic range and improves image quality. The adaptive filter with predetermined shape is placed at the x-ray beam such that the x-ray intensity at the detector surface is flat. However, adaptive filter alters the mean dose to the breast, as well as volume distribution of the dose. Methods: The dose was measured using a 14 cm diameter cylindrical acrylic breast phantom. An acrylic adaptive filter was fabricated to match the 14 cm diameter of the phantom. The dose was measured using ion chamber inserted into holes distributed along the radius of the phantom from the center to the edge. The radial distribution of dose was measured and fitted by an analytical function and the volume distribution and mean value of dose was calculated. The measurements were performed at 40, 60, 90, and 120 kVp tube voltages and 6.6 mGy air kerma. Results: The adaptive filt...

  19. Chemical filtration of Cr (VI) with electrospun chitosan nanofiber membranes.

    Science.gov (United States)

    Li, Lei; Li, Yanxiang; Yang, Chuanfang

    2016-04-20

    Chitosan nanofibers (average diameter of 75nm) were electrospun on polyester (PET) scrim to form composite nanofiber membranes with controlled pore size. The membranes were then stacked as a membrane bed for chemical filtration of Cr (VI) of 1-5mg/L. The performance of the bed with respect to loading capacity at breakthrough, bed saturation and utilization efficiency were carefully investigated. The results showed that while these three parameters were dependent on pH, flow rate, flow distribution and packed pattern of the membrane, the latter two were less affected by feed Cr (VI) concentration and bed length. The maximum bed loading capacity for 1mg/L Cr (VI) filtration at breakthrough was found to be 16.5mg-chromium/g-chitosan, higher than the static adsorption capacity of 11.0mg-chromium/g-chitosan using nanofiber mats, indicating the membranes' better potential for dynamic adsorption. The minimum bed length required to avoid breakthrough was determined to be three layers of stacked membranes with nanofiber deposition density of 1g/m(2) by applying bed depth service time (BDST) model.

  20. Mechanistic evaluation of virus clearance by depth filtration.

    Science.gov (United States)

    Venkiteshwaran, Adith; Fogle, Jace; Patnaik, Purbasa; Kowle, Ron; Chen, Dayue

    2015-01-01

    Virus clearance by depth filtration has not been well-understood mechanistically due to lack of quantitative data on filter charge characteristics and absence of systematic studies. It is generally believed that both electrostatic interactions and sized based mechanical entrapment contribute to virus clearance by depth filtration. In order to establish whether the effectiveness of virus clearance correlates with the charge characteristics of a given depth filter, a counter-ion displacement technique was employed to determine the ionic capacity for several depth filters. Two depth filters (Millipore B1HC and X0HC) with significant differences in ionic capacities were selected and evaluated for their ability to eliminate viruses. The high ionic capacity X0HC filter showed complete porcine parvovirus (PPV) clearance (eliminating the spiked viruses to below the limit of detection) under low conductivity conditions (≤2.5 mS/cm), achieving a log10 reduction factor (LRF) of > 4.8. On the other hand, the low ionic capacity B1HC filter achieved only ∼2.1-3.0 LRF of PPV clearance under the same conditions. These results indicate that parvovirus clearance by these two depth filters are mainly achieved via electrostatic interactions between the filters and PPV. When much larger xenotropic murine leukemia virus (XMuLV) was used as the model virus, complete retrovirus clearance was obtained under all conditions evaluated for both depth filters, suggesting the involvement of mechanisms other than just electrostatic interactions in XMuLV clearance.

  1. Performance of rapid-grown KDP crystals with continuous filtration

    Institute of Scientific and Technical Information of China (English)

    Guohang Hu; Yueliang Wang; Junxiu Chang; Xiaoyi Xie; Yuanan Zhao; Hongji Qi; Jianda Shao

    2015-01-01

    Rapid growth processing of KDP crystals was improved by employing continuous filtration to eliminate bulk defects.The performances of the KDP crystals, including scattering defects, laser damage resistance and transmittance, were measured and analyzed. Compared with rapid-grown KDP without continuous filtration, the transmittance in the nearinfrared was increased by at least 2%, almost all of ‘micron size’ defects were eliminated and ‘sub-micron size’ defects were decreased by approximately 90%. Laser damage testing revealed that the laser-induced damage thresholds(LIDTs),as well as the consistency of the LIDTs from sample to sample, were improved greatly. Moreover, it identified that‘micron size’ defects were the precursors which initiated laser damage at relative lower laser fluence(4–6 J cm-2),and there was a lower correlation between smaller size scattering defects and laser damage initiation. The improved consistency in the LIDTs, attributed to elimination of ‘micron size’ defects, and LIDT enhancement originated from the decreased absorption of the KDP crystals.

  2. Controversies on glomerular filtration from Ludwig to the present.

    Science.gov (United States)

    Steinhausen, M; Endlich, K

    1996-01-01

    Since Ludwig's theory of filtration in the glomerulus is generally accepted, current research interest has focussed on the regulation of this process. The main determinants of glomerular filtration rate are glomerular capillary pressure and glomerular blood flow, which are adjusted via resistance changes in the pre- and postglomerular vasculature. Overall pre- and postglomerular resistances were first determined by micropuncture in superficial glomeruli. While the predominant source of postglomerular resistance is the efferent arteriole, several results indicate that preglomerular resistance might be rather uniformly distributed among all preglomerular vessels (interlobar, arcuate and interlobular arteries and afferent arterioles). Over the last decade, several techniques have been used to visualize renal vessels and to study the action of various vasoactive hormones thereon. Results obtained with the split hydronephrotic kidney model, which permits in vivo microscopy of all renal vessels, provide evidence for a differential regulation of the various preglomerular vessels by vasoactive hormones. In particular, mediators of inflammation almost selectively constrict interlobar and arcuate arteries. We conclude that, given the renal vascular architecture, differential regulation of preglomerular vessels can alter haemodynamic parameters specifically for different nephron populations.

  3. Controlled shear filtration: A novel technique for animal cell separation.

    Science.gov (United States)

    Vogel, J H; Kroner, K H

    1999-06-20

    A novel rotary microfiltration technique specifically suited for the separation of animal cells has been developed. The concept allows the independent adjustment of wall shear stress, transmembrane pressure, and residence time, allowing straightforward optimization of the microfiltration process. By using a smooth, conically shaped rotor, it is possible to establish a controlled shear field in which animal cells experience a significant hydrodynamic lift away from the membrane surface. It is shown in preliminary experiments that shear-induced cell-rupture speeds up membrane clogging and that cell debris poses the most significant problem in harvesting of BHK cell cultures by dynamic microfiltration. However, a threshold value of shear stability exists which depends on the frequency of passing the shear field, the residence time in the shear field, as well as on cell status. By operating close to this threshold value, cell viability can be maintained while concentration polarization is efficiently minimized. By applying this concept, it is possible to attain flux rates several times higher compared to conventional crossflow filtration. Controlled shear filtration (CSF) can be used for batch harvesting as well as for cell retention in high cell density systems. In batch harvesting of hIL-2 from rBHK cell culture, a constant flux rate of 290 L h-1 m-2 has been adjusted without indication of membrane clogging or fouling.

  4. Improved techniques for hyperbaric filtration of fine coal slurry

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J.; Wang, X.H.; Parekh, B.K. [University of Kentucky, Lexington, KY (United States). Center for Applied Energy Research

    2010-07-01

    Dewatering of fine clean coal slurry is one of the most important unit operations of a coal-cleaning circuit. However, an efficient and economic dewatering method is still eluding the coal industry. In this study hyperbaric (high pressure) filtration studies were conducted on a froth flotation product obtained from a coal preparation plant processing Pittsburgh No. 8 seam coal. The fine coal slurry (42 weight percent minus 25 {mu}m) could be dewatered to a low moisture (24%) using 482kPa (70psi) pressure. This article describes two novel approaches for improving dewatering of the fine coal slurry using hyperbaric filtration, such as using a modified filter support and split-size dewatering. The modified filter support system and the split-sizing at 25 {mu}m (500mesh) provided 21.5% and 15.9% moisture filter cake, which was about 10% and 34% improvement in moisture reduction in the filter cake moisture, respectively. Combining both the approaches with the addition of a nonionic flocculant provided a filter cake with 10.5% moisture, which was about a 56% improvement in moisture reduction.

  5. The PBW Filtration, Demazure Modules and Toroidal Current Algebras

    Directory of Open Access Journals (Sweden)

    Evgeny Feigin

    2008-10-01

    Full Text Available Let L be the basic (level one vacuum representation of the affine Kac-Moody Lie algebra ^g. The m-th space F_m of the PBW filtration on L is a linear span of vectors of the form x_1dots x_lv_0, where l ≤ m, x_i in ^g and v_0 is a highest weight vector of L. In this paper we give two descriptions of the associated graded space L^{gr} with respect to the PBW filtration. The ''top-down'' description deals with a structure of L^{gr} as a representation of the abelianized algebra of generating operators. We prove that the ideal of relations is generated by the coefficients of the squared field e_θ(z2, which corresponds to the longest root θ. The ''bottom-up'' description deals with the structure of L^{gr} as a representation of the current algebra g otimes C[t]. We prove that each quotient F_m/F_{m-1} can be filtered by graded deformations of the tensor products of m copies of g.

  6. Triamcinolone acetonide concentration after filtration of the solvent agent.

    Science.gov (United States)

    Spandau, Ulrich H M; Derse, Mathias; Schmitz-Valckenberg, Paul; Papoulis, Christos; Sagstetter, Bernd-Udo; Stiefvater, Karlheinz; Jonas, Jost B

    2005-04-01

    To determine the amount of triamcinolone acetonide and the preservative benzyl alcohol after filtration. Laboratory investigation. The probes were prepared by two different hospital pharmacies. The probes of the first pharmacy included 20 probes with 25-mg triamcinolone acetonide, unfiltered (n = 5 probes) or filtered (n = 5), or with 4-mg triamcinolone acetonide, filtered (n = 5) or unfiltered (n = 5). The probes for the second pharmacy were filtered (n = 3) probes of 25-mg triamcinolone acetonide. For the probes of the first pharmacy, triamcinolone acetonide dosages were 2.4 +/- 0.8 mg, 3.1 +/- 0.6 mg, 12.8 +/- 0.7 mg, and 23.4 +/- 2.3 mg, respectively, for the filtered 4-mg probes, unfiltered 4-mg probes, filtered 25-mg probes, and unfiltered 25-mg probes, respectively. For the second pharmacy, mean triamcinolone acetonide dosage was 23.8 +/- 0.6 mg for the 25-mg filtered probes and contained benzyl alcohol in a mean concentration of 0.0013 +/- 0.0001 mg/0.1 ml. Depending on the method employed and the pharmacy, preparation of triamcinolone acetonide including filtration of the solvent agent leads to a marked inter-pharmacy variation and a relatively low intra-pharmacy variation in the reduction of triamcinolone acetonide dosage.

  7. Purification of hemoglobin by tangential flow filtration with diafiltration.

    Science.gov (United States)

    Elmer, Jacob; Harris, David R; Sun, Guoyong; Palmer, Andre F

    2009-01-01

    A recent study by Palmer, Sun, and Harris (Biotechnol. Prog., 25:189-199, 2009) demonstrated that tangential flow filtration (TFF) can be used to produce HPLC-grade bovine and human hemoglobin (Hb). In this current study, we assessed the quality of bovine Hb (bHb) purified by introducing a 10 L batch-mode diafiltration step to the previously mentioned TFF Hb purification process. The bHb was purified from bovine red blood cells (RBCs) by filtering clarified RBC lysate through 50 nm (stage I) and 500 kDa (stage II) hollow fiber (HF) membranes. The filtrate was then passed through a 100 kDa (stage III) HF membrane with or without an additional 10 L diafiltration step to potentially remove additional small molecular weight impurities. Protein assays, SDS-PAGE, and LC-MS of the purified bHb (stage III retentate) reveal that addition of a diafiltration step has no effect on bHb purity or yield; however, it does increase the methemoglobin level and oxygen affinity of purified bHb. Therefore, we conclude that no additional benefit is gained from diafiltration at stage III and a three stage TFF process is sufficient to produce HPLC-grade bHb.

  8. Internal filtration in dialyzers with different membrane permeabilities.

    Science.gov (United States)

    Sato, Yuichi; Kimura, Kenjiro; Chikaraishi, Tatsuya

    2010-07-01

    Over the last decade, hemodialysis with enhanced internal filtration (IF) has been investigated as an alternative to conventional dialysis. Several factors affect IF, including the geometry and permeability of hollow-fiber dialyzers. Although various studies have been performed, the association between IF and membrane permeability has not been fully examined because of the difficulty in measuring IF. Therefore, in this study, we set up an experimental circuit and attempted to directly measure IF as well as membrane permeability in five dialyzers. In the circuit, we placed two dialyzers of the same type in series, and a special sampling port between them, thereby making it possible to determine IF by measuring the extent to which blood was concentrated between the two dialyzers. We showed that a significant amount of IF occurred in this tandem-dialyzer circuit, ranging from 23.5 to 100 ml/min, which increased linearly with increasing membrane permeability. We also showed that membrane permeability was reduced in the first dialyzer to a greater extent than in the second one after four hours of circulation, suggesting that filtration caused substantial membrane fouling. In this study we practically demonstrated that membrane permeability is highly relevant to the phenomenon of IF.

  9. Intermittent filtration of bacteria and colloids in porous media

    Science.gov (United States)

    Auset, Maria; Keller, Arturo A.; Brissaud, François; Lazarova, Valentina

    2005-09-01

    Intermittent filtration through porous media used for water and wastewater treatment can achieve high pathogen and colloid removal efficiencies. To predict the removal of bacteria, the effects of cyclic infiltration and draining events (transient unsaturated flow) were investigated. Using physical micromodels, we visualized the intermittent transport of bacteria and other colloids in unsaturated porous media. Column experiments provided quantitative measurements of the phenomena observed at the pore scale. Tagged Escherichia coli and a conservative tracer (NaI) were introduced in an initial pulse into a 1.5 m sand column. Subsequent hydraulic flushes without tagged bacteria or tracer were repeated every 4 hours for the next 4 days, during which outflow concentrations were monitored. Breakthrough behavior between colloids and dissolved tracer differed significantly, reflecting the differences in transport processes. Advancement of the wetting front remobilized bacteria which were held in thin water films, attached to the air-water interface (AWI), or entrapped in stagnant pore water between gas bubbles. In contrast, the tracer was only remobilized by diffusion from immobile to mobile water. Remobilization led to successive concentration peaks of bacteria and tracer in the effluent but with significant temporal differences. Observations at the pore-scale indicated that the colloids were essentially irreversibly attached to the solid-water interface, which explained to some extent the high removal efficiency of microbes in the porous media. Straining, cluster filtration, cell lysis, protozoa grazing, and bacteriophage parasitism could also contribute to the removal efficiency of bacteria.

  10. Turbidity removal: Gravel and charcoal as roughing filtration media

    Directory of Open Access Journals (Sweden)

    Josiah A. Adeyemo

    2010-10-01

    Full Text Available Roughing filtration is an important pre-treatment process for wastewater, because it efficiently separates fine solid particles over prolonged periods, without the addition of chemicals. For this study, a pilot plant was designed at Delmas Coal Mine in the Mpumalanga province of South Africa. The design and sizing of the pilot plant was guided by Wegelin’s design criteria. Gravel was used as a control medium because it is one of the most commonly used roughing filter media and because it was used in developing the criteria. We compared the performance of gravel as a filter medium to that of another locally available material, charcoal, for the removal of turbidity in wastewater. The pilot plant was monitored continuously for 90 days from commissioning until the end of the project. The overall performance of the roughing filter in turbidity removal, using gravel or charcoal, was considered efficient for the pre-treatment of waste water. Charcoal performed slightly better than gravel as a filter medium for the removal of turbidity, possibly because charcoal has a slightly higher specific surface area and porosity than gravel, which could enhance sedimentation and other filtration processes, such as adsorption, respectively.

  11. Harder–Narasimhan filtration for rank 2 tensors and stable coverings

    Indian Academy of Sciences (India)

    ALFONSO ZAMORA

    2016-08-01

    We construct a Harder--Narasimhan filtration for rank 2 tensors, where there does not exist any such notion {/it a priori,} as coming from a GIT notion of maximal unstability. The filtration associated to the 1-parameter subgroup of Kempf giving the maximal way to destabilize, in the GIT sense, a point in the parameter space of the construction of the moduli space of rank 2 tensors over a smooth projective complex variety, does not depend on a certain integer used in the construction of the moduli space, for large values of the integer. Hence, this filtration is unique and we define the Harder--Narasimhan filtration for rank 2 tensors as this unique filtration coming from GIT. Symmetric rank 2 tensors over smooth projective complex curves define curve coverings lying on a ruled surface, hence we can translate the stability condition to define stable coverings and characterize the Harder--Narasimhan filtration in terms of intersection theory.

  12. Effects of different Helicobacter pylori culture filtrates on growth of gastric epithelial cells

    Institute of Scientific and Technical Information of China (English)

    Yan-Guo Yan; Gang Zhao; Jin-Ping Ma; Shi-Rong Cai; Wen-Hua Zhan

    2008-01-01

    AIM: To study the effects of different Helicobacter pylori (H py/orl) culture filtrates on growth of gastric epithelial cells.METHODS: Broth culture filtrates of H pylori were prepared. Gastric epithelial cells were treated with the filtrates, and cell growth was determined by growth curve and flow cytometry. DNA damage of gastric epithelial cells was measured by single-cell microgel electrophoresis.RESULTS: Gastric epithelial cells proliferated actively when treated by CagA-gene-positive broth culture filtrates, and colony formation reached 40%. The number of cells in S phase increased compared to controls. Comet assay showed 41.2% comet cells in GES-1 cells treated with CagA-positive filtrates (P<0.05).CONCLUSION: CagA-positive filtrates enhance the changes in morphology and growth characteristics of human gastric epithelial tumor cells. DNA damage maybe one of the mechanisms involved in the growth changes.

  13. Effect of blood flow rate on internal filtration in a high-flux dialyzer with polysulfone membrane.

    Science.gov (United States)

    Sakiyama, Ryoichi; Ishimori, Isamu; Akiba, Takashi; Mineshima, Michio

    2012-09-01

    Internal filtration/backfiltration (IF/BF) of a dialyzer depends on several parameters. This study evaluated the effect of the blood flow rate (Q (B)) on the internal filtration flow rate (Q (IF)) measured using Doppler ultrasonography for a high-flux dialyzer with a polysulfone membrane, APS-15E. In an in vitro study, bovine blood was circulated through the dialyzer, at a Q (B) of 100-350 mL/min. The clearances (CL) of creatinine, β(2)-microglobulin, and α(1)-microglobulin were then investigated. Q (IF) increased with the Q (B) value. A good correlation was obtained between Q (IF) and the pressure difference between the pressures at the inlet of the blood compartment and the pressure at the outlet of the dialysate compartment. The creatinine CL values strongly depended on Q (B) because molecular diffusion was dominant. The β(2)-microglobulin CL also depended on Q (B), because its removal rate seemed to be affected by both diffusive and convective transport caused by the IF/BF. An extremely low CL value was obtained for α(1)-microglobulin because of its low diffusivity and membrane fouling induced by proteins plugging the membrane. In conclusion, the IF/BF in the dialyzer strongly depends on Q (B). Furthermore, the dependence of the solute clearance on Q (B) decreased with increasing molecular size of the solute because of the decrease in diffusivity through the membrane.

  14. Permeability, Strength and Filtration Performance for Uncoated and Titania-Coated Clay Wastewater Filters

    Directory of Open Access Journals (Sweden)

    Masturi

    2012-01-01

    Full Text Available Problem statement: Wastewater problems continue to be a relevant issue, particularly in urban areas. One promising low-cost material for manufacturing porous ceramics as water filter is clay. Clays can be blended with other materials such as polymers to obtain functional ceramic materials. Approach: Ceramic wastewater filters were fabricated from clay using both sol-gel and simple mixing methods followed by hot-pressing and calcination. Polyethylene Glycol (PEG was used as a pore-forming agent. Results: Varying the clay:PEG ratio modified the membrane permeability between 1.65×10-16 m2 and 3.16×10-15 m2 for the sol-gel membranes and between 1.38×10-16 and 8.72×10-13 m2 for membranes prepared by simple mixing. The strength ranged from 0.28 MPa-1.71 MPa for the sol-gel membranes and from 0.05-0.90 MPa for samples prepared by simple mixing. The filtration performance was tested using aqueous solutions of Methylene Blue (MB. The concentrations of MB remaining in the solution varied from 0.98-1.44% for sol-gel filters and from 1.50-38.05% for filters prepared by simple mixing. Conclusion: We succeeded in making ceramic as filter from clay. The porous ceramic can be used to reducing concentration of pollutant simulated. The model introduced has succeeded to explain the experimental observations with percolation approximation.

  15. Probing deviations from traditional colloid filtration theory by atomic forces microscopy.

    Energy Technology Data Exchange (ETDEWEB)

    Reno, Marissa Devan

    2005-12-01

    Colloid transport through saturated media is an integral component of predicting the fate and transport of groundwater contaminants. Developing sound predictive capabilities and establishing effective methodologies for remediation relies heavily on our ability to understand the pertinent physical and chemical mechanisms. Traditionally, colloid transport through saturated media has been described by classical colloid filtration theory (CFT), which predicts an exponential decrease in colloid concentration with travel distance. Furthermore, colloid stability as determined by Derjaguin-Landau-Veney-Overbeek (DLVO) theory predicts permanent attachment of unstable particles in a primary energy minimum. However, recent studies show significant deviations from these traditional theories. Deposition in the secondary energy minimum has been suggested as a mechanism by which observed deviations can occur. This work investigates the existence of the secondary energy minimum as predicted by DLVO theory using direct force measurements obtained by Atomic Forces Microscopy. Interaction energy as a function of separation distance between a colloid and a quartz surface in electrolyte solutions of varying ionic strength are obtained. Preliminary force measurements show promise and necessary modifications to the current experimental methodology have been identified. Stringent surface cleaning procedures and the use of high-purity water for all injectant solutions is necessary for the most accurate and precise measurements. Comparisons between direct physical measurements by Atomic Forces Microscopy with theoretical calculations and existing experimental findings will allow the evaluation of the existence or absence of a secondary energy minimum.

  16. Impact of 50% Synthesized Iso-Paraffins (SIP) on Middle Distillate Fuel Filtration and Coalescence

    Science.gov (United States)

    2014-10-30

    Impact of 50% Synthesized Iso-Paraffins (SIP) on Middle Distillate Fuel Filtration and Coalescence NF&LCFT REPORT 441/15-003 30 October 2014...October 2014 Page 1 Impact of 50% Synthesized Iso-Paraffins (SIP) on Middle Distillate Fuel Filtration and Coalescence 1.0 BACKGROUND In...Paraffins (SIP) on Middle 5a. CONTRACT NUMBER N/A Distillate Fuel F-76 Filtration and Coalescence 5b. GRANT NUMBER N/A 5c. PROGRAM

  17. The direct filtration in a conventional water treatment plant; La filtracion directa en una ETAP convencional

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Quiros, F. [Canal de Isabel II, Madrid (Spain)

    1995-06-01

    The article describes the difficulty of the decantation of low turbidity water. Direct filtration and in-line filtration can be available alternative treatment process to coagulation, flocculation, with the minimum required chemical dosage especially coagulants, less sludge production and lower operation cost. The adaptation of conventional treatment plant to direct filtration system with recuperation of filters backwash water by eliminating the decantation, is relatively simple. The result to apply this process shows an efficient filters performance for the same effluent quality. (Author)

  18. ACCUMULATION OF ALKALIS IN THE RECYCLING FILTRATE OF THE PHOSPHOGYPSUM PULPS

    OpenAIRE

    ANTANAS KAZILIUNAS; MARYTE BACAUSKIENE

    2011-01-01

    Sodium and potassium combinations existing in phosphogypsum are highly soluble and remain in the filtrate, their amount increasing with each recycle. It has been determined that the amount of alkalis in the recycling filtrate depends on an amount of alkalis in uncleaned phosphogypsum, a number of recycles in the filtrate, the technology of the phosphogypsum pulp preparation and an amount of soluble phosphates. New phosphate formations composed in an acid medium (pH = 4.5-5) are well crystaliz...

  19. Sterile Filtration of Highly Concentrated Protein Formulations: Impact of Protein Concentration, Formulation Composition, and Filter Material.

    Science.gov (United States)

    Allmendinger, Andrea; Mueller, Robert; Huwyler, Joerg; Mahler, Hanns-Christian; Fischer, Stefan

    2015-10-01

    Differences in filtration behavior of concentrated protein formulations were observed during aseptic drug product manufacturing of biologics dependent on formulation composition. The present study investigates filtration forces of monoclonal antibody formulations in a small-scale set-up using polyvinylidene difluoride (PVDF) or polyethersulfone (PES) filters. Different factors like formulation composition and protein concentration related to differences in viscosity, as well as different filtration rates were evaluated. The present study showed that filtration behavior was influenced by the presence or absence of a surfactant in the formulation, which defines the interaction between filter membrane and surface active formulation components. This can lead to a change in filter resistance (PES filter) independent on the buffer system used. Filtration behavior was additionally defined by rheological non-Newtonian flow behavior. The data showed that high shear rates resulting from small pore sizes and filtration pressure up to 1.0 bar led to shear-thinning behavior for highly concentrated protein formulations. Differences in non-Newtonian behavior were attributed to ionic strength related to differences in repulsive and attractive interactions. The present study showed that the interplay of formulation composition, filter material, and filtration rate can explain differences in filtration behavior/filtration flux observed for highly concentrated protein formulations thus guiding filter selection.

  20. PRE-FILTRATION IN BOULDER AND SLOW SAND FILTRATION WITH NON-WOVEN SYNTHETIC LAYERS AND GRANULATED VEGETAL COAL TO IMPROVE QUALITY IN WASTEWATER TREATED BY CONSTRUCTED WETLANDS

    OpenAIRE

    Paterniani, JES; da Silva, MJM; Ribeiro, TAP; Barbosa, M.

    2011-01-01

    The objective of this study was the comparison between two filtration systems, being one composed of a boulder pre-filter followed by a slow filter with sand as filtration media and a non-woven synthetic fabric in the upper part, and the other one composed of a boulder pre-filter followed by a slow filter with sand as filtration media and granular activated charcoal and a non-woven synthetic fabric in the upper part, for the purification of household effluents treated in cultivated beds, to b...

  1. Antimicrobial filtration with electrospun poly(vinyl alcohol) nanofibers containing benzyl triethylammonium chloride: Immersion, leaching, toxicity, and filtration tests.

    Science.gov (United States)

    Park, Jeong-Ann; Kim, Song-Bae

    2017-01-01

    Antimicrobial electrospun poly(vinyl alcohol) (PVA) nanofibers were synthesized by impregnating benzyl triethylammonium chloride (BTEAC) as an antimicrobial agent into PVA nanofibers. The BTEAC-PVA nanofibers were heat-methanol treated during the preparation for various tests. The BTEAC-PVA nanofibers became more hydrophilic than the PVA nanofibers due to incorporation of BTEAC. Through heat-methanol treatment, thermal property, crystallinity, and water stability of BTEAC-PVA nanofibers were improved considerably. The immersion test shows that heat-methanol treatment has an advantage over heat treatment to maintain BTEAC content in BTEAC-PVA nanofibers. The acute toxicity test demonstrates that the 24-h EC50 and 48-h EC50 values (EC50 = median effective concentration) of BTEAC to Daphnia magna were 113 and 90 mg/L, respectively. The leaching test indicates that the BTEAC concentration leached from BTEAC-PVA nanofibers was far below the concentration affecting the immobilization of D. magna. For antimicrobial filtration tests, the BTEAC-PVA nanofibers were deposited onto glass fiber filter. The antimicrobial filtration test was conducted against bacteria (Escherichia coli, Staphylococcus aureus) and bacteriophages (MS2, PhiX174), demonstrating that the BTEAC-PVA nanofibers could enhance the removal of E. coli and S. aureus considerably but not the removal of MS2 and PhiX174 under dynamic flow conditions.

  2. Reverse osmosis followed by activated carbon filtration for efficient removal of organic micropollutants from river bank filtrate.

    Science.gov (United States)

    Kegel, F Schoonenberg; Rietman, B M; Verliefde, A R D

    2010-01-01

    Drinking water utilities in Europe are faced with a growing presence of organic micropollutants in their water sources. The aim of this research was to assess the robustness of a drinking water treatment plant equipped with reverse osmosis and subsequent activated carbon filtration for the removal of these pollutants. The total removal efficiency of 47 organic micropollutants was investigated. Results indicated that removal of most organic micropollutants was high for all membranes tested. Some selected micropollutants were less efficiently removed (e.g. the small and polar NDMA and glyphosate, and the more hydrophobic ethylbenzene and napthalene). Very high removal efficiencies for almost all organic micropollutants by the subsequent activated carbon, fed with the permeate stream of the RO element were observed except for the very small and polar NDMA and 1,4-dioxane. RO and subsequent activated carbon filtration are complementary and their combined application results in the removal of a large part of these emerging organic micropollutants. Based on these experiments it can be concluded that the robustness of a proposed treatment scheme for the drinking water treatment plant Engelse Werk is sufficiently guaranteed.

  3. REACT-Mod: a mathematical model for transient calculation of chemical reactions with U-Pu-Np-Tc in the aqueous nitric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Tachimori, Shoichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kitamura, Tatsuaki

    1996-10-01

    A computer code REACT-Mod which simulates various chemical reactions in an aqueous nitric acid solution involving uranium, plutonium, neptunium, technetium etc. e.g., redox, radiolytic and disproportionation reactions of 68, was developed based on the kinetics model. The numerical solution method adopted in the code are two, a kinetics model totally based on the rate law of which differential equations are solved by the modified Porsing method, and a two-step model based on both the rate law and equilibrium law. Only the former treats 27 radiolytic reactions. The latter is beneficially used to have a quick and approximate result by economical computation. The present report aims not only to explain the concept, chemical reactions treated and characteristics of the model but also to provide details of the program for users of the REACT-Mod code. (author)

  4. Influence of container structures and content solutions on dispensing time of ophthalmic solutions

    Directory of Open Access Journals (Sweden)

    Keiji Yoshikawa

    2010-05-01

    Full Text Available Keiji Yoshikawa1, Hiroshi Yamada21Yoshikawa Eye Clinic, Tokyo, Japan; 2Santen Pharmaceutical Co., Ltd., Osaka, JapanPurpose: To investigate the influence of container structures and content solutions on the time of dispensing from eye dropper bottles.Methods: Eye dropper bottle models, solution models (filtrate water/surfactant solution and a dispensing time measuring apparatus were prepared to measure the dispensing time.Results: With filtrate water and pressure thrust load of 0.3 MPa, the dispensing time significantly increased from 1.1 ± 0.5 seconds to 4.6 ± 1.1 seconds depending on the decrease of inner aperture diameters from 0.4 mm to 0.2 mm (P < 0.0001. When using the bottle models with inner aperture diameters of 0.4 mm or larger, the dispensing time became constant. The dispensing time using surfactant solution showed the same tendency as above. When pressure thrust load was large (0.07 MPa, the solution flew out continuously with inner aperture diameters of 0.4 mm or larger and the dispensing time could not be measured. The inner aperture diameter most strongly explained the variation of the dispensing time in both the content solutions in the multiple linear regression analysis (filtrate water: 46%, R2 = 0.462, surfactant solution: 56%, R2 = 0.563.Conclusions: Among content solutions and container structures, the dispensing time was mostly influenced by the diameter of the inner aperture of bottles.Keywords: dispensing time, model eye dropper bottle, model ophthalmic solution, nozzle internal space volume, nozzle inner aperture diameter

  5. Electrospun ceramic fibermats for filtration applications in lunar missions for in-habitat applications

    Science.gov (United States)

    Biswas, Apratim

    associated with general handling and fixture used for holding the filtration media. Electrospinning was selected as the fabrication method due to superior performance towards fiber diameter uniformity and the ability to decrease fiber diameters to the nm level. Filtration tests have been carried out on such fibermats concerning a number of key variables such as fiber diameter, particle size, pressure drop and more. Multifunctionality, as filter material and as photocatalyst, allows the filters to be regenerable. Furthermore, organic vapors (odors) and plant super hormones (ethylene gas) can be oxidized. This is key for a sustainable human base where food needs to be grown and the level of odors in habitat has to be minimized. Ceramic materials based on TiO2 and titania composites where selected. To enhance the catalytic properties doping with a pentavalent ion, viz. niobium, with varying concentrations was done. Materials were electrospun and characterized. An increase of niobium yields stabilization of the anatase phase at 600°C as evident from XRD patterns. Higher treatment temperatures allow a transformation to rutile. This is important since the semiconductor junction of anatase to rutile decreases electron-hole recombination rate, which enhances the photocatalytic activity. Furthermore, doping anatase with niobium increases the porosity and with it the catalytically active area. In fact the specific surface area of titania fibers increases by almost 6 times when doped with only 2.5 at% niobium. However, in this work reduced photocatalytic activity was observed. It is hypothesized that phase separation of the niobium rather than doping in a solid solution occurred which will change the properties of the semiconductor junction in an unfavorable way. The other possible explanation is the decrease in the anatase -- rutile semiconductor junction in niobium doped titania.

  6. Is the use of particle air filtration justified? Costs and benefits of filtration with regard to health effects, building cleaning and occupant productivity

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Clausen, Geo; Weschler, Charles J.

    2008-01-01

    Estimates of costs and the corresponding benefits of particle filtration have been derived for a standard office building. Reduction in occupants’ exposure to particles during their workday is anticipated to reduce their morbidity and mortality. Filtration may also reduce the costs associated......, the sensitivity of the results to these parameters was evaluated as part of this study. The study also acknowledges that the benefits-to-costs ratio depends on the perspective of the stakeholder: the employer renting the building is impacted by occupant performance and building energy costs; the building owner...... is impacted by maintenance of the building and its HVAC system; society is impacted by the employees’ health and welfare. Regardless of perspective, particle filtration is anticipated to lead to annual savings significantly exceeding the running costs for filtration. However, economic losses resulting from...

  7. Water Purification by Shock Electrodialysis: Deionization, Filtration, Separation, and Disinfection

    CERN Document Server

    Deng, Daosheng; Braff, William A; Schlumpberger, Sven; Suss, Matthew E; Bazant, Martin Z

    2014-01-01

    The development of energy and infrastructure efficient water purification systems are among the most critical engineering challenges facing our society. Water purification is often a multi-step process involving filtration, desalination, and disinfection of a feedstream. Shock electrodialysis (shock ED) is a newly developed technique for water desalination, leveraging the formation of ion concentration polarization (ICP) zones and deionization shock waves in microscale pores near to an ion selective element. While shock ED has been demonstrated as an effective water desalination tool, we here present evidence of other simultaneous functionalities. We show that, unlike electrodialysis, shock ED can thoroughly filter micron-scale particles and aggregates of nanoparticles present in the feedwater. We also demonstrate that shock ED can enable disinfection of feedwaters, as approximately $99\\%$ of viable bacteria (here \\textit{E. coli}) in the inflow were killed or removed by our prototype. Shock ED also separates...

  8. Hot-gas filtration for pressurized fluidized-bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Chang, R.; Kuby, W.

    1984-03-01

    This topical report discusses the status of the work, conducted under EPRI contract 1336-4, on the evaluation and development of ceramic filter hot gas cleanup technology for pressurized fluidized bed combustion. This topical report represents the status of the work through September 1983. The goal of the effort is to achieve 6000 h of operation on a 13-filter durability test rig. The work includes two parallel tasks. The first is construction of a durability test facility, operation of the facility with an initial candidate filter media installed, and assessment of results. The second task includes a literature survey to identify state-of-the-art ceramic fibers suitable for high-temperature gas filtration applications and filter testing in a single-filter test facility to assess the performance of promising new filter media. The best candidate will be chosen for further evaluation in the durability facility.

  9. Development of injection moulded, ultrasonically welded immiscible phase filtration devices

    DEFF Research Database (Denmark)

    Kistrup, Kasper

    for ultrasonic welding, suitable for microfluidic systems. A methodology has been established where energy directors can be quickly added to existing mould inserts, using laser micromachining. The produced device was performance tested by isolating methicillin-resistant Staphylococcus aureus from bovine whole....... The device appliesmagnetic bead-based solid-phase extraction for nucleic acid extraction from biological samples, using the immiscible phase filtration (IPF) approach. Device development has employed injection moulding for part fabrication and ultrasonic welding for bonding. Rapid prototyping...... was accomplished by micromilling and laser micromachining of mould inserts, allowing for design-to-production of chips within a day. The rapid overall fabrication cycle of a few minutes per chip allowed for conducting research in a single-use disposable fashion. Chip development has centred on manufacturing...

  10. Home water treatment by direct filtration with natural coagulant.

    Science.gov (United States)

    Babu, Raveendra; Chaudhuri, Malay

    2005-03-01

    Seeds of the plant species Strychnos potatorum and Moringa oleifera contain natural polyelectrolytes which can be used as coagulants to clarify turbid waters. In laboratory tests, direct filtration of a turbid surface water (turbidity 15-25 NTU, heterotrophic bacteria 280-500 cfu ml(-1), and fecal coliforms 280-500 MPN 100 ml(-1)), with seeds of S. potatorum or M. oleifera as coagulant, produced a substantial improvement in its aesthetic and microbiological quality (turbidity 0.3-1.5 NTU, heterotrophic bacteria 5-20 cfu ml(-1) and fecal coliforms 5-10 MPN 100 ml(-1)). The method appears suitable for home water treatment in rural areas of developing countries. These natural coagulants produce a 'low risk' water; however, additional disinfection or boiling should be practised during localised outbreaks/epidemics of enteric infections.

  11. Ceramic Ultra Filtration Membrane Bioreactor for Domestic Wastewater Treatment

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A long term domestic wastewater treatment experiment was conducted using a recirculating ceramic ultra filtration membrane bioreactor (CUFMB) system. Three experiments were run with a hydraulic retention time of 5h, sludge retention times of 5d, 15d, and 30d and a membrane surface flow rate of 4m/s. The experiment studied the membrane fouling mechanism and cleaning techniques. The results show that a CUFMB system can provide continuous good quality effluent which is completely acceptable for reuse. The system is also not affected by fluctuations of the inlet flow. The CUFMB sludge loading rate is similar to that of conventional biological treatment units. However, the volumetric loading rate of the CUFMB is 24 times that of conventional biological treatment units. Membrane fouling occurs due to channel clogging, which could be easily removed, and surface fouling, which can be effectively removed using the method described in this work which includes water rinsing, base cleaning, and acid washing.

  12. Simulation of C-CP Fiber-Based Air Filtration

    Directory of Open Access Journals (Sweden)

    Christopher L. Cox, Ph.D.

    2008-06-01

    Full Text Available The overall goal of this project is to develop High Efficiency Particulate Air (HEPA filter media, using conventional fiber spinning techniques, with lower pressure drop than current media through the use of shaped fibers. Capillary-channeled polymer (C-CP fibers are gaining interest for use in a range of separations applications. This paper focuses on modeling air filtration where the filter consists of C-CP fibers. A variety of numerical tools are being used in this effort, including a finite element flow solver and Brownian dynamics simulation. Aspects of these techniques in relation to the problem at hand will be described, and simulation results including comparisons to round-fiber filters will be presented. The primary result presented here is the significant difference in predicted pressure drop between a prototype C-CP filter and a round-fiber filter with equal total cross-sectional area.

  13. The Use of Coupled Plasma Filtration Adsorption in Traumatic Rhabdomyolysis

    Directory of Open Access Journals (Sweden)

    Mario Pezzi

    2017-01-01

    Full Text Available Severe musculoskeletal injuries induce the release of sarcoplasmic elements such as muscle enzymes, potassium, and myoglobin in the systemic circulation. The circulating myoglobin damages the glomerulus and renal tubules. Conventional haemodialysis is not able to remove myoglobin, due to its high molecular weight (17,8 kilodaltons [kDa]. We treated four traumatic rhabdomyolysis patients with Coupled Plasma Filtration Adsorption (CPFA in order to remove myoglobin followed by 14 hours of Continuous Veno-Venous Hemofiltration (CVVH. During the treatment, all patients showed clinical improvement with a decrease in muscular (creatine kinase [CK] and myoglobin and renal (creatinine and potassium damage indices. One patient, in spite of full renal recovery, died of cerebral haemorrhage on the 26th day of hospital stay.

  14. Flocculation, hydrophobic agglomeration and filtration of ultrafine coal

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Z. [University of British Columbia, Vancouver, BC (Canada). Department of Mineral and Mineral Process Engineering

    1999-07-01

    Selective flocculation tests were run on three types of coal and three additives in tests on a new hydrophobic agglomeration process using hydrophobic latices. The coals differed widely in surface wettability. The additives were hydrophobic latexes, a semi-hydrophobic flocculant, and a typical hydrophilic polyelectrolyte. The results show that coal wettability is very important in selective flocculation. UBC-1 hydrophobic latex flocculated hydrophobic coal particles only, while the polyelectrolyte flocculated all the coal samples and minerals that were tested. Tests of oil agglomeration using kerosene emulsified with surfactants of various ionic properties show that even oxidized coals can be agglomerated, if cationic surfactants are used to emulsify the oil. The hydrophobic latex and emulsified oils also significantly increase filtration rate and reduce filter cake moisture content.

  15. Liquid filtration properties in gravel foundation of railroad tracks

    Science.gov (United States)

    Strelkov, A.; Teplykh, S.; Bukhman, N.

    2016-08-01

    Railway bed gravel foundation has a constant permanent impact on urban ecology and ground surface. It is only natural that larger objects, such as railway stations, make broader impact. Surface run-off waters polluted by harmful substances existing in railroad track body (ballast section) flow along railroad tracks and within macadam, go down into subterranean ground flow and then enter neighbouring rivers and water basins. This paper presents analytic calculations and characteristics of surface run-off liquid filtration which flows through gravel multiple layers (railroad track ballast section). The authors analyse liquids with various density and viscosity flowing in multi-layer porous medium. The paper also describes liquid stationary and non-stationary weepage into gravel foundation of railroad tracks.

  16. Glomerular filtration rate in cows estimated by a prediction formula.

    Science.gov (United States)

    Murayama, Isao; Miyano, Anna; Sato, Tsubasa; Iwama, Ryosuke; Satoh, Hiroshi; Ichijyo, Toshihiro; Sato, Shigeru; Furuhama, Kazuhisa

    2014-12-01

    To testify the relevance of Jacobsson's equation for estimating bovine glomerular filtration rate (GFR), we prepared an integrated formula based on its equation using clinically healthy dairy (n=99) and beef (n=63) cows, and cows with reduced renal function (n=15). The isotonic, nonionic, contrast medium iodixanol was utilized as a test tracer. The GFR values estimated from the integrated formula were well consistent with those from the standard multisample method in each cow strain, and the Holstein equation prepared by a single blood sample in Holstein dairy cows. The basal reference GFR value in healthy dairy cows was significantly higher than that in healthy beef cows, presumably due to a breed difference or physiological state difference. It is concluded that the validity for the application of Jacobsson's equation to estimate bovine GFR is proven and it can be used in bovine practices.

  17. Organic-inorganic membranes for filtration of corn distillery

    Directory of Open Access Journals (Sweden)

    Myronchuk Valeriy G.

    2016-01-01

    Full Text Available Organic-inorganic membranes were obtained by modification of polymer microfiltration membrane with inorganic ion-exchangers, which form secondary porosity inside macroporous substrate (zirconium hydrophosphate or simultaneously in the macroporous substrate and active layer, depending of the particle size (from ≈50 nm up to several microns. Precipitation of the inorganic constituent is considered from the point of view of Ostwald-Freundlich equation. Such processes as pressing test in deionized water and filtration of corn distillery at 1-6 bar were investigated. Theoretical model allowing to establish fouling mechanism, was applied. It was found that the particles both in the substrate and active layer prevent fouling of the membrane with organics and provide rejection of colloidal particles.

  18. Allelopathic Effects of Cyanobacterial Filtrates on Baltic Diatom

    Science.gov (United States)

    Śliwińska, Sylwia; Latała, Adam

    2012-01-01

    Allelopathy may be one of the factors affecting the formation of massive and harmful algal blooms in aquatic environments. Recent studies indicate that blooms of cyanobacteria in the Baltic Sea has grown significantly in last decades, so it is important to determine the allelopathic interactions between the dominant species of cyanobacteria and microalgae. In this work we investigated the influence of allelopathic compounds on the growth of Skeletonema marinoi by addition of cell-free filtrate of the Baltic cyanobacterium Nodularia spumigena cultures grown under different temperature (15-25°C). Additionally the effects of filtrates of both an exponential and a stationary growing culture of N. spumigena were tested on diatom. These studies indicate that high temperature affected the donor species by increasing its production of allelochemicals. The highest drop of growth of analyzed diatom were observed after the addition of cell-free filtrate obtained from N. spumigena grown at 25°C and constituted 70% of their control. N. spumigena was only allelopathic in exponential growth phase, whereas the cyanobacteria filtrate from stationary phase have any effect on S. marinoi. These findings suggest that N. spumigena may reveal allelopathic activity and that the production of allelopathic substances is influenced by the temperature and growth phase of cyanobacteria. Allelopatia może być kluczowym czynnikiem wpływającym na tworzenie się masowych zakwitów sinic w wielu wodnych ekosystemach. Badania pokazują, że zakwity sinic w Morzu Bałtyckim w ostatnich dekadach znacznie się nasiliły, dlatego tak ważne jest określenie stopnia oddziaływania allelopatycznego dominujących w tym akwenie gatunków fitoplanktonu. W przeprowadzonych badaniach określono wpływ związków allelopatycznych produkowanych przez bałtycką sinicę Nodularia spumigena hodowaną w różnych temperaturach (15-25°C) na wzrost okrzemki Skeletonema marinoi. Dodatkowo w niniejszej pracy por

  19. MULTILAYER POROUS COMPOSITE FROM WASTE GLASS FOR WATER FILTRATION

    Directory of Open Access Journals (Sweden)

    M. P. Aji

    2015-07-01

    Full Text Available Multilayer porous composite have been produced through the heating process at temperature T=700oC for 2.5 h. Single layered porous composite was made with a varied mass percentage of from PEG polymer  1% to 10%. Double-layered porous composite were made by the arrangement of porosity (4:3%, (4:2% and (3:2%, while the three-layers porous composite have an arrangement (4:3:2%. Performance of multilayer porous composite for water filtration with pollutants of methylene blue 100 ppm was estimated from the absorbance spectrum. Rejection of methylene blue pollutants from single layered porous composite increases when the fraction of PEG polymer tend to be smaller in the matrix. Meanwhile, the double layered porous composite has a degradation of methylene blue pollutants are better than one layer. Triple layered porous composite have good performance for the water filtration where all the pollutants of methylene blue be able to be filtered.   Komposit pori berlapis telah dihasilkan dengan proses pemanasan pada temperatur T=700oC selama 2.5 jam. Komposit pori satu lapis dibuat dengan variasi persen massa polimer PEG 1% hingga 10%. Komposit pori dua lapis dibuat dengan susunan porositas (4:3%, (4:2% dan (3:2%, sedangkan komposit pori tiga lapis memiliki susunan porositas (4:3:2%. Kinerja komposit pori berlapis untuk filter air dengan polutan methylene blue 100 ppm diestimasi dari spektrum absorbansi. Rejeksi polutan methylene blue dari komposit pori satu lapis meningkat saat fraksi polimer PEG cenderung lebih kecil dalam matrik komposit. Sedangkan, komposit pori dua lapis memiliki kemampuan untuk degradasi polutan methylene blue yang lebih baik dari satu lapis. Komposit pori tiga lapis memiliki kinerja yang baik untuk filter air dimana seluruh polutan methylene blue mampu disaring. 

  20. Ultrastructural model for size selectivity in glomerular filtration.

    Science.gov (United States)

    Edwards, A; Daniels, B S; Deen, W M

    1999-06-01

    A theoretical model was developed to relate the size selectivity of the glomerular barrier to the structural characteristics of the individual layers of the capillary wall. Thicknesses and other linear dimensions were evaluated, where possible, from previous electron microscopic studies. The glomerular basement membrane (GBM) was represented as a homogeneous material characterized by a Darcy permeability and by size-dependent hindrance coefficients for diffusion and convection, respectively; those coefficients were estimated from recent data obtained with isolated rat GBM. The filtration slit diaphragm was modeled as a single row of cylindrical fibers of equal radius but nonuniform spacing. The resistances of the remainder of the slit channel, and of the endothelial fenestrae, to macromolecule movement were calculated to be negligible. The slit diaphragm was found to be the most restrictive part of the barrier. Because of that, macromolecule concentrations in the GBM increased, rather than decreased, in the direction of flow. Thus the overall sieving coefficient (ratio of Bowman's space concentration to that in plasma) was predicted to be larger for the intact capillary wall than for a hypothetical structure with no GBM. In other words, because the slit diaphragm and GBM do not act independently, the overall sieving coefficient is not simply the product of those for GBM alone and the slit diaphragm alone. Whereas the calculated sieving coefficients were sensitive to the structural features of the slit diaphragm and to the GBM hindrance coefficients, variations in GBM thickness or filtration slit frequency were predicted to have little effect. The ability of the ultrastructural model to represent fractional clearance data in vivo was at least equal to that of conventional pore models with the same number of adjustable parameters. The main strength of the present approach, however, is that it provides a framework for relating structural findings to the size