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Sample records for bed adsorption chromatography

  1. Critical evaluation and comparison of fluid distribution systems for industrial scale expanded bed adsorption chromatography columns

    DEFF Research Database (Denmark)

    Arpanaei, Ayyoob; Heebøll-Nielsen, Anders; Hubbuch, Jürgen;

    2008-01-01

    The hydrodynamic properties of an expanded bed contactor with 30 cm or 150 cm internal diameter, which employs a rotating or oscillating fluid distributor, were compared to prototype columns of 60 cm or 150 cm diameter employing local stirring (fixed wall nozzles plus central bottom mounted stirrer...

  2. Recombinant protein purification using gradient-assisted simulated moving bed hydrophobic interaction chromatography. Part I: selection of chromatographic system and estimation of adsorption isotherms.

    Science.gov (United States)

    Palani, Sivakumar; Gueorguieva, Ludmila; Rinas, Ursula; Seidel-Morgenstern, Andreas; Jayaraman, Guhan

    2011-09-16

    The design of gradient simulated moving bed (SMB) chromatographic processes requires an appropriate selection of the chromatographic system followed by the determination of adsorption isotherm parameters in the relevant range of mobile phase conditions. The determination of these parameters can be quite difficult for recombinant target proteins present in complex protein mixtures. The first part of this work includes the estimation of adsorption isotherm parameters for streptokinase and a lumped impurity fraction present in an Escherichia coli cell lysate for a hydrophobic interaction chromatography (HIC) matrix. Perturbation experiments were carried out using a Butyl Sepharose matrix with purified recombinant protein on buffer equilibrated columns as well as with crude cell lysate saturated columns. The Henry constants estimated for streptokinase were found to exhibit in a wide range a linear dependence on the salt concentration in the mobile phase. These parameters were applied in subsequent investigations to design a simulated moving bed (SMB) process capable to purify in a continuous manner recombinant streptokinase from the E. coli cell lysate. PMID:21816402

  3. DNA-induced inter-particle cross-linking during expanded bed adsorption chromatography - Impact on future support design

    DEFF Research Database (Denmark)

    Theodossiou, Irini; Thomas, Owen R. T.

    2002-01-01

    of the mean hydrated particle radii, the anion-exchangers were observed to split into three distinct, but different clusters in each case. The highest index of surface packing of DNA was observed for two prototype pellicular supports, one derivatised with highly charged high molecular mass polyethyleneimine...... of anion-exchangers, the bed heights dropped progressively as DNA molecules physically cross-linked neighbouring adsorbent particles together, to form severely aggregated fluidised beds. In plots of dynamic binding capacities and absolute changes in bed porosity at maximum contraction, against the inverse...... exhibited a three-fold higher tendency to interact with neighbouring particles in the presence of DNA than that of the dextran DEAE support. The implications of these findings on the design of future expanded bed materials for separation of both proteins and nucleic acids are discussed....

  4. Performance comparison of suspended bed and batch contactor chromatography.

    Science.gov (United States)

    Quiñones-García, I; Rayner, I; Levison, P R; Dickson, N; Purdom, G

    2001-01-26

    In some applications, the purification and recovery of biomolecules is performed via a cascade of batch adsorption and desorption stages using agitated contactors and related filtration devices. Suspended bed chromatography is a recent process-scale innovation that is applicable to these separations. This hybrid technique exploits the benefits of combining batch adsorption in an agitated contactor with elution in an enclosed column system. To some extent, the process is similar to batch contactor chromatography but can be fully contained and significantly quicker. The process has two steps; first the fluid containing the sample is mixed with the adsorbent in a stirred tank. Second, the slurry suspension is transferred directly into a specialized column, such as an IsoPak column. The media with the adsorbed product is formed as a packed bed, whilst the suspension liquid is passed out of the column. The product is then eluted from the packed bed utilizing standard column-chromatography techniques. The performance of the suspended bed and the agitated contactor operations are demonstrated both by full-scale experimental results and process simulations. The purification of ovalbumin from a hen-egg white feedstock by anion-exchange chromatography was used as a case study in order to prove the concept. With the availability of both pump-packed systems and shear-resistant media, suspended bed chromatography is a better alternative for a range of applications than the traditional batch separations using agitated contactors. PMID:11218119

  5. Expanded bed adsorption of an alkaline lipase from Pseudomona cepacia.

    Science.gov (United States)

    da Silva Padilha, Giovana; Curvelo-Santana, José Carlos; Alegre, Ranulfo Monte; Tambourgi, Elias Basile

    2009-02-15

    An extracellular lipase was isolated from Pseudomona cepacia by expanded bed adsorption on an Amberlite 410 ion-exchange resin. Enzyme characterization and hydrodynamic study of a chromatography column were done. Enzyme purification was done at three condition of expanded bed height (H): at one and half (6cm), at two (8cm) and at three (12cm) times the fixed bed height (H(0)=4cm). The results showed that the experimental data was fitted to the Richardson and Zaki equation, and the comparison between the experimental and calculated terminal velocities showed low relative error. In enzyme purification for better condition, a purification factor of about 80 times was found at 6cm of expanded bed height, or 1.5 times of expansion degree. Purified lipase had an optimal pH and a temperature of 8 and 37 degrees C, respectively. PMID:19162572

  6. Experimental Investigation on a Novel Four-bed Adsorption Chiller

    Science.gov (United States)

    Ng, Kim Choon; Chua, Hui Tong; Wang, Jin Bao; Wang, Xiao Lin; Kashiwagi, Takao; Akisawa, Atsushi; Saha, Bidyut Baran

    A prototype multi-bed regenerative adsorption chiller with a novel four-bed operation mode has been designed, fabricated and tested. The rating tests are conducted under assorted ARI coolant, using a purpose-built rating. The 4.bed design exhibits superior heat extraction capability from the heat source as its "slave-first-then-master" arrangement permits individual bed to maximize energy utilization in a batch cycle. Overall system performance of chiller is evaluated for various adsorption-desorption cycle and switching time at assorted coolant inlet temperatures. For fair comparison, the 4-bed chiller is also compared with that of a two-bed mode at the same working conditions.

  7. Comparative study of hydrodynamic behavior of liquid expanded bed adsorption: mathematical and short-cut methods

    Directory of Open Access Journals (Sweden)

    M. Jahanshahi

    2009-06-01

    Full Text Available Liquid fluidized/expanded bed adsorption (LF/EBA is a novel chromatography technique for capturing target biomolecules directly from crude feedstock in downstream processing. To widely extend the LF/EBA technology in biological industries, a better understanding of the expanded-bed behavior is necessary to maximize its efficient applications. In this study, streamline adsorbent was loaded into the column and the bed was subjected to physical and hydrodynamical experiments. Hydrodynamic characteristics of the bed (e.g., Daxl and Bo with different settled bed height (SBH=5,6,7,8,9,10,11,12cm along with a variety of column diameters (1,1.6,2.5 cm have been investigated based on exact mathematical as well as approximate short-cut methods. It was found that the increasing column diameter promoted bed mixing, which was undesirable, and the optimal values for the bed expansion and SBH based on minimal liquid mixing were 80%-130% and 8-10 cm, respectively. However, exploiting the short-cut method for the bed hydrodynamic assessments also demonstrated results as good as the mathematical method. Hydrodynamic behavior of liquid fluidized bed adsorption and the generic application of the short-cut method and its potential as a simple method for study of hydrodynamic performance is discussed.

  8. Expanded and packed bed albumin adsorption on fluoride modified zirconia.

    Science.gov (United States)

    Mullick, A; Griffith, C M; Flickinger, M C

    1998-11-01

    The expanded bed characteristics of 75-103microm fluoride-modified zirconia (FmZr) particles synthesized by a fed batch oil emulsion process were investigated. These particles are distinguished from commercially available expanded-bed adsorbents by virtue of their high density (2.8 g/cc) and the mixed mode protein retention mechanism which allows for the retention of both cationic and anionic proteins. The linear velocity versus bed porosity data agree with the Richardson-Zaki relationship with the terminal velocity in infinite medium of 2858.4 cm/h and a bed expansion index of 5.1. Residence time distribution (RTD) studies and bovine serum albumin (BSA) adsorption studies were performed as a function of the height of the settled bed to the column diameter (H:D) ratio and degree of bed expansion with superficial velocities of 440 to 870 cm/h. The settled bed, a 2x expanded bed, and a 3x expanded bed were studied for the H:D ratios of 1:1, 2:1, and 3:1. The dynamic binding capacity (DBC) at 5% breakthrough was low (2-8 mg BSA/mL settled bed) and was independent of the H:D ratio or the degree of bed expansion. The saturation DBC was 32.3 +/- 7.0 mg BSA/mL settled bed. The adsorption-desorption kinetics and intraparticle diffusion for protein adsorption on FmZr (38-75 micrometer) were investigated by studying the packed bed RTD and BSA adsorption as a function of temperature and flow rate. The data show that the adsorption-desorption kinetics along with intraparticle diffusion significantly influence protein adsorption on FmZr. Low residence times ( approximately 0.8 min) of BSA result in a DBC at 5% breakthrough which is 3.5-fold lower compared to that at 6-fold higher protein residence time. At low linear velocity (45 cm/h) the breakthrough curve is nearly symmetrical and becomes asymmetrical and more dispersed at higher linear velocity (270 cm/h) due to the influence of slow adsorption-desorption kinetics and intraparticle diffusion. Bioeng 60: 333-340, 1998. PMID

  9. Phase 2 Methyl Iodide Deep-Bed Adsorption Tests

    Energy Technology Data Exchange (ETDEWEB)

    Soelberg, Nick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Watson, Tony [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    Nuclear fission produces fission products (FPs) and activation products, including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Research, demonstrations, and some reprocessing plant experience have indicated that diatomic iodine can be captured with efficiencies high enough to meet regulatory requirements. Research on the capture of organic iodides has also been performed, but to a lesser extent. Several questions remain open regarding the capture of iodine bound in organic compounds. Deep-bed methyl iodide adsorption testing has progressed according to a multi-laboratory methyl iodide adsorption test plan. This report summarizes the second phase of methyl iodide adsorption work performed according to this test plan using the deep-bed iodine adsorption test system at the Idaho National Laboratory (INL), performed during the second half of Fiscal Year (FY) 2014. Test results continue to show that methyl iodide adsorption using AgZ can achieve total iodine decontamination factors (DFs, ratios of uncontrolled and controlled total iodine levels) above 1,000, until breakthrough occurred. However, mass transfer zone depths are deeper for methyl iodide adsorption compared to diatomic iodine (I2) adsorption. Methyl iodide DFs for the Ag Aerogel test adsorption efficiencies were less than 1,000, and the methyl iodide mass transfer zone depth exceeded 8 inches. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption under various conditions specified in the methyl iodide test plan, and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.

  10. FY-2015 Methyl Iodide Deep-Bed Adsorption Test Report

    Energy Technology Data Exchange (ETDEWEB)

    Soelberg, Nicholas Ray [Idaho National Lab. (INL), Idaho Falls, ID (United States); Watson, Tony Leroy [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-30

    Nuclear fission produces fission and activation products, including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Deep-bed methyl iodide adsorption testing has continued in Fiscal Year 2015 according to a multi-laboratory methyl iodide adsorption test plan. Updates to the deep-bed test system have also been performed to enable the inclusion of evaporated HNO3 and increased NO2 concentrations in future tests. This report summarizes the result of those activities. Test results showed that iodine adsorption from gaseous methyl iodide using reduced silver zeolite (AgZ) resulted in initial iodine decontamination factors (DFs, ratios of uncontrolled and controlled total iodine levels) under 1,000 for the conditions of the long-duration test performed this year (45 ppm CH3I, 1,000 ppm each NO and NO2, very low H2O levels [3 ppm] in balance air). The mass transfer zone depth exceeded the cumulative 5-inch depth of 4 bed segments, which is deeper than the 2-4 inch depth estimated for the mass transfer zone for adsorbing I2 using AgZ in prior deep-bed tests. The maximum iodine adsorption capacity for the AgZ under the conditions of this test was 6.2% (6.2 g adsorbed I per 100 g sorbent). The maximum Ag utilization was 51%. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.

  11. FY-2015 Methyl Iodide Deep-Bed Adsorption Test Report

    International Nuclear Information System (INIS)

    Nuclear fission produces fission and activation products, including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Deep-bed methyl iodide adsorption testing has continued in Fiscal Year 2015 according to a multi-laboratory methyl iodide adsorption test plan. Updates to the deep-bed test system have also been performed to enable the inclusion of evaporated HNO3 and increased NO2 concentrations in future tests. This report summarizes the result of those activities. Test results showed that iodine adsorption from gaseous methyl iodide using reduced silver zeolite (AgZ) resulted in initial iodine decontamination factors (DFs, ratios of uncontrolled and controlled total iodine levels) under 1,000 for the conditions of the long-duration test performed this year (45 ppm CH3I, 1,000 ppm each NO and NO2, very low H2O levels [3 ppm] in balance air). The mass transfer zone depth exceeded the cumulative 5-inch depth of 4 bed segments, which is deeper than the 2-4 inch depth estimated for the mass transfer zone for adsorbing I2 using AgZ in prior deep-bed tests. The maximum iodine adsorption capacity for the AgZ under the conditions of this test was 6.2% (6.2 g adsorbed I per 100 g sorbent). The maximum Ag utilization was 51%. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.

  12. Evaluation of center-cut separations applying simulated moving bed chromatography with 8 zones.

    Science.gov (United States)

    Santos da Silva, Francisco Vitor; Seidel-Morgenstern, Andreas

    2016-07-22

    Different multi-column options to perform continuous chromatographic separations of ternary mixtures have been proposed in order to overcome limitations of batch chromatography. One attractive option is given by simulated moving bed chromatography (SMB) with 8 zones, a process that offers uninterrupted production, and, potentially, improved economy. As in other established ternary separation processes, the separation sequence is crucial for the performance of the process. This problem is addressed here by computing and comparing optimal performances of the two possibilities assuming linear adsorption isotherms. The conclusions are presented in a decision tree which can be used to guide the selection of system configuration and operation. PMID:27328885

  13. Improving washing strategies of human mesenchymal stem cells using negative mode expanded bed chromatography.

    Science.gov (United States)

    Cunha, Bárbara; Silva, Ricardo J S; Aguiar, Tiago; Serra, Margarida; Daicic, John; Maloisel, Jean-Luc; Clachan, John; Åkerblom, Anna; Carrondo, Manuel J T; Peixoto, Cristina; Alves, Paula M

    2016-01-15

    The use of human mesenchymal stem cells (hMSC) in clinical applications has been increasing over the last decade. However, to be applied in a clinical setting hMSC need to comply with specific requirements in terms of identity, potency and purity. This study reports the improvement of established tangential flow filtration (TFF)-based washing strategies, further increasing hMSC purity, using negative mode expanded bed adsorption (EBA) chromatography with a new multimodal prototype matrix based on core-shell bead technology. The matrix was characterized and a stable, expanded bed could be obtained using standard equipment adapted from what is used for conventional packed bed chromatography processes. The effect of different expansion rates on cell recovery yield and protein removal capacity was assessed. The best trade-off between cell recovery (89%) and protein clearance (67%) was achieved using an intermediate expansion bed rate (1.4). Furthermore, we also showed that EBA chromatography can be efficiently integrated on the already established process for the downstream processing (DSP) of hMSC, where it improved the washing efficiency more than 10-fold, recovering approximately 70% of cells after global processing. This strategy showed not to impact cell viability (>95%), neither hMSC's characteristics in terms of morphology, immunophenotype, proliferation, adhesion capacity and multipotent differentiation potential. PMID:26739915

  14. Application of capillary gas chromatography mass spectrometry/computer techniques to synoptic survey of organic material in bed sediment

    Science.gov (United States)

    Steinheimer, T.R.; Pereira, W.E.; Johnson, S.M.

    1981-01-01

    A bed sediment sample taken from an area impacted by heavy industrial activity was analyzed for organic compounds of environmental significance. Extraction was effected on a Soxhlet apparatus using a freeze-dried sample. The Soxhlet extract was fractionated by silica gel micro-column adsorption chromatography. Separation and identification of the organic compounds was accomplished by capillary gas chromatography/mass spectrometry techniques. More than 50 compounds were identified; these include saturated hydrocarbons, olefins, aromatic hydrocarbons, alkylated polycyclic aromatic hydrocarbons, and oxygenated compounds such as aldehydes and ketones. The role of bed sediments as a source or sink for organic pollutants is discussed. ?? 1981.

  15. Multi-bed Mass Recovery Adsorption Cycle -Improving Performance

    Science.gov (United States)

    Khan, Md. Zafar Iqbal; Saha, Bidyut Baran; Alam, K. C. Amanul; Miyazaki, Takahiko; Akisawa, Atsushi; Kashiwagi, Takao

    The study aims at clarifying the performance of a 3-bed, mass recovery silica gel-water adsorption refrigeration cycle. The cycle with mass recovery can be driven by waste heat at near ambient temperatures (between 50 and 90°C). All components of adsorption cycle are operated in different pressure levels. The 3-bed chiller with mass recovery process utilizes those pressure levels to enhance the refrigerant mass circulation. The innovative adsorption chiller comprises with three sorption elements (SEs), one evaporator and one condenser. The configuration of SE1 and SE2 are uniform but the configuration of SE3 is taken as half of SE1 or SE2. Two cycles (cycle-1, cycle-2) with mass recovery process are used and compare the performance with each other. In cycle-1, mass recovery process occurs between SE3 with either SE1 or SE2 and no mass recovery between SE1 and SE2 occurs. In cycle-2, mass recovery process occurs between SE1 and SE2, and no mass recovery process occurs between SE3 with either SE1 or SE2. The mathematical model shown herein is solved numerically. Simulated results are obtained from transient to cyclic steady state. Simulated results show that the COP and SCP of cycle-1 are better than those of cycle-2.

  16. Isolation of α-arbutin from Xanthomonas CGMCC 1243 fermentation broth by macroporous resin adsorption chromatography.

    Science.gov (United States)

    Liu, Chunqiao; Zhang, Peng; Liu, Luo; Xu, Tao; Tan, Tianwei; Wang, Fang; Deng, Li

    2013-04-15

    α-Arbutin is a glycosylated hydroquinone which has inhibitory function against tyrosinase. In this work, a one-step isolation of α-arbutin from Xanthomonas CGMCC 1243 fermentation broth by macroporous resin adsorption chromatography was investigated. The research results indicated that S-8 resin offered the best adsorption and desorption capacities for α-arbutin than others and its equilibrium adsorption data were well-fitted to the Freundlich isotherm. In order to optimize the operating parameters for separating α-arbutin, dynamic adsorption and desorption tests on S-8 column chromatography were carried out. Under optimized conditions (adsorption volume of 7 bed volume (BV), mobile phase of 25% (v/v) ethanol solution and elution volume of 3 BV), the purity and recovery of α-arbutin were 97.3% (w/w) and 90.9% (w/w), respectively. The product was identified as α-arbutin by (13)C NMR and (1)H NMR analysis. Moreover, we scaled up S-8 column from laboratory test (10 cm × 2 cm ID) to large scale (500 cm × 100 cm ID) without diminishing α-arbutin yield. In conclusion, the results in this work provide a one-step and cost-effective method for large-scale production of α-arbutin.

  17. Adsorption gas chromatography with 150-ms 216Po

    International Nuclear Information System (INIS)

    A gas chromatography apparatus was developed, which allows experiments with volatile radionuclides having shorter half-lives than one second. This apparatus was tested with the 150-ms isotope 216Po. Experimental data were compared with a Monte Carlo model to determine the adsorption enthalpy ΔHa. (author) 2 figs., 2 refs

  18. Purification of L-Lysine in Simulated Moving Bed and Fixed-Bed Chromatography%模拟移动床色谱及固定床色谱纯化L-赖氨酸

    Institute of Scientific and Technical Information of China (English)

    ROBATJAZI Seyed Mortaza; SHOJAOSADATI Seyed Abbas; KARBASY Seyed Mojtaba

    2004-01-01

    L-Lysine was produced by a microbial process utilizing a Corynebacterium glutamicum (ATCC 21799) strain. L-Lysine was purified from the cultivated medium by fixed-bed and simulated moving bed (SMB) chromatography. The separation conditions including pH, eluent concentration and Lys+ and Lys2+ adsorption isotherms were studied in batch adsorption. The column capacity, eluent flow rate and eluent concentration have been studied in fixed-bed chromatography. Maximum purification rate of lysine was obtained as 0.066 g/(g*h) (per gram resin and per hour) at an eluent flow rate of 10 mL/min in fixed-bed chromatography. The results obtained from SMB were 0.11 g/(g*h) for L-lysine purification rate and 96% for L-lysine recovery.

  19. Phase 1 Methyl Iodide Deep-Bed Adsorption Tests

    Energy Technology Data Exchange (ETDEWEB)

    Nick Soelberg; Tony Watson

    2014-08-01

    Nuclear fission results in the production of fission products (FPs) and activation products including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Research, demonstrations, and some reprocessing plant experience have indicated that diatomic iodine can be captured with efficiencies high enough to meet regulatory requirements. Research on the capture of organic iodides has also been performed, but to a lesser extent [Jubin 2012b]. Several questions remain open regarding the capture of iodine bound in organic compounds. Deep-bed methyl iodide adsorption testing has progressed according to a multi-laboratory methyl iodide adsorption test plan. This report summarizes the first phase of methyl iodide adsorption work performed according to this test plan using the deep-bed iodine adsorption test system at the Idaho National Laboratory (INL), performed during Fiscal Year (FY) 2013 and early FY-2014. Testing has been performed to address questions posed in the test plan, and followed the testing outline in the test plan. Tests established detection limits, developed procedures for sample analysis with minimal analytical interferences, and confirmed earlier results that show that the methyl iodide reacts when in contact with the AgZ sorbent, and not significantly in the gas flow upstream of the sorbent. The reaction(s) enable separation of the iodine from the organic moiety, so that the iodine can chemisorb onto the sorbent. The organic moiety can form other compounds, some of which are organic compounds that are detected and can be tentatively identified using GC-FID and GCMS. Test results also show that other gas constituents (NOx and/or H2O) can affect the methyl iodide reactions. With NOx and H2O present in the gas stream, the majority of uncaptured iodine exiting iodine-laden sorbent beds is in the form of I2 or HI, species that

  20. Numerical Simulation of Asynchronous Simulated Moving Bed Chromatography

    Institute of Scientific and Technical Information of China (English)

    卢建刚

    2004-01-01

    Asynchronous simulated moving bed chromatography (ASMBC), known also as the "VARICOL" process, is more efficient and flexible than the well-known and traditional simulated moving bed chromatography (SMBC). A detailed model of ASMBC, taking account of non-linear competitive isotherms, mass transfer parameters, and complex port switching schedule parameters, was developed to simulate the complex dynamics of ASMBC.The simulated performance is in close agreement with the experimental data of chiral separation reported in the literature. The simulation results show that ASMBC can achieve the performance similar to SMBC with fewer columns and can achieve better performance than SMBC with the same total column number. All design and operation parameters can be chosen correctly by numerical simulation. This detailed ASMBC model and the numerical technique are useful for design, operation, optimization and scale-up of ASMBC.

  1. High gradient magnetic separation versus expanded bed adsorption: a first principle comparison

    DEFF Research Database (Denmark)

    Hubbuch, Jürgen; Matthiesen, D.B.; Hobley, Timothy John;

    2001-01-01

    system exhibited substantially enhanced productivity over expanded bed adsorption when operated at processing velocities greater than 48 m h(-1). Use of the bacitracin- linked magnetic supports for a single cycle of batch adsorption and subsequent capture by high gradient magnetic separation...... at a processing rate of 12 m h(-1) resulted in a 2.2-fold higher productivity relative to expanded bed adsorption, while an increase in adsorbent collection rate to 72 m h(-1) raised the productivity to 10.7 times that of expanded bed adsorption. When the number of batch adsorption cycles was then increased...

  2. Activated Carbon Adsorption Characteristics of Multi-component Volatile Organic compounds in a Fixed Bed Adsorption Bed

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jong Hoon; Rhee, Young Woo [Chungnam National University, Daejeon (Korea, Republic of); Lee, Sihyun [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

    2016-04-15

    This study aims to examine absorption characteristics of toluene, isopropyl alcohol (IPA), ethyl acetate (EA), and ternary-compounds, all of which are widely used in industrial processes, by means of four types of commercial activated carbon substances. It turned out that among the three types of volatile organic compounds, the breakthrough point of activated carbon and that of IPA, whose affinity was the lowest, were the lowest, and then that of EA and that of toluene in the order. With the breakthrough point of IPA, which was the shortest, as the standard, changes in the breakthrough points of unary-compounds, binary-compounds, and ternary-compounds were examined. As a result, it turned out that the larger the number of elements, the lower the breakthrough point. This resulted from competitive adsorption, that is, substitution of substances with a low level of affinity with those with a high level of affinity. Hence, the adsorption of toluene-IPA-EA and ternary-compounds require a design of the activated carbon bed based on the breakthrough of IPA, and in the design of activated carbon beds in actual industries as well, a substance whose level of affinity is the lowest needs to be the standard.

  3. Expanded bed adsorption as a fast technique for the large-scale purification of the complete isoform pool of Ber e 1, the major allergen from Brazil nuts

    NARCIS (Netherlands)

    Boxtel, E.L. van; Koningsveld, G.A. van; Koppelman, S.J.; Broek, L.A.M. van den; Voragen, A.G.J.; Gruppen, H.

    2006-01-01

    A new, fast, large-scale purification method for Ber e 1, the major allergen from Brazil nuts, using expanded bed adsorption (EBA) chromatography, is presented. Using EBA, crude extracts can be applied to a fluidized column, which allows the unhindered passage of particulate impurities, thereby avoi

  4. Anion exchange purification of plasmid DNA using expanded bed adsorption.

    Science.gov (United States)

    Ferreira, G N; Cabral, J M; Prazeres, D M

    2000-01-01

    Recent developments in gene therapy with non-viral vectors and DNA vaccination have increased the demand for large amounts of pharmaceutical-grade plasmid DNA. The high viscosity of process streams is of major concern in the purification of plasmids, since it can cause high back pressures in column operations, thus limiting the throughput. In order to avoid these high back pressures, expanded bed anion exchange chromatography was evaluated as an alternative to fixed bed chromatography. A Streamline 25 column filled with 100 ml of Streamline QXL media, was equilibrated with 0.5 M NaCl in TE (10 mM Tris, 1 mM EDTA, pH = 8.0) buffer at an upward flow of 300 cmh-1, E. coli lysates (obtained from up to 3 liters of fermentation broth) were injected in the column. After washing out the unbound material, the media was allowed to sediment and the plasmid was eluted with 1 M NaCl in TE buffer at a downward flow of 120 cmh-1. Purification factors of 36 +/- 1 fold, 26 +/- 0.4 plasmid purity, and close to 100% yields were obtained when less than one settled column volume of plasmid feed was injected. However, both recovery yield and purity abruptly decreased when larger amounts were processed-values of 35 +/- 2 and 5 +/- 0.7 were obtained for the recovery yield and purity, respectively, when 250 ml of feedstock were processed. In these cases, gel clogging and expansion collapse were observed. The processing of larger volumes, thus larger plasmid quantities, was only possible by performing an isopropanol precipitation step prior to the chromatographic step. This step led to an enhancement of the purification step.

  5. Application of ultrasonic backscattering for level measurement and process monitoring of expanded-bed adsorption columns.

    Science.gov (United States)

    Thelen, T V; Mairal, A P; Thorsen, C S; Ramirez, W F

    1997-01-01

    Expanded-bed adsorption is a newly commercialized technique for the purification of proteins from cellular debris in downstream processing. An expanded bed presents the possibility of protein recovery in a single step, eliminating the often costly clarification processing steps such as ultrafiltration, centrifugation, and precipitation. A major obstacle to the successful commercialization of this technology is the inability to accurately monitor and control the bed height in these systems. Fluctuations in the feedstock viscosity are common during normal operation and tend to make the operation and control of expanded beds for biological applications complex and difficult. We develop a level measurement technique based upon ultrasonics. It is shown that this technique has great promise for bed-height measurement in expanded-bed adsorption systems. Furthermore, the bed-height measurement can be used in feedback control strategies for bed-height regulation. The proposed ultrasonic sensor is also capable of monitoring for plugging and bubbling in the column. PMID:9336988

  6. Mathematical modeling of salt-gradient ion-exchange simulated moving bed chromatography for protein separations

    Institute of Scientific and Technical Information of China (English)

    卢建刚

    2004-01-01

    The salt-gradient operation mode used in ion-exchange simulated moving bed chromatography (SMBC) can improve the efficiency of protein separations. A detailed model that takes into account any kind of adsorption/ion-exchange equilibrium, salt gradient, size exclusion, mass transfer resistance, and port periodic switching mechanism, was developed to simulate the complex dynamics. The model predictions were verified by the experimental data on upward and downward gradients for protein separations reported in the literature. All design and operating parameters (number, configuration, length and diameter of columns, particle size, switching period, flow rates of feed, raffinate, desorbent and extract, protein concentrations in feed, different salt concentrations in desorbent and feed) can be chosen correctly by numerical simulation. This model can facilitate the design, operation, optimization, control and scale-up of salt-gradient ion-exchange SMBC for protein separations.

  7. A Study on the Fixed-bed Adsorption of Heavy Metal Ions over Chitosan Bead

    Energy Technology Data Exchange (ETDEWEB)

    Chung, K.H. [Department of Petrochemical Engineering, Hanlyo University, Chonnam (Korea)

    1999-02-01

    Fixed-bed adsorption of metal ions on chitosan bead was studied to remove heavy metal ions in waste water. Chitin was extracted from crab shell and chitosan was prepared by deacetylation of the chitin. The chitosan in bead was used as an adsorbent for heavy metal ions. Freundlich and Langmuir isotherm was determined from the experimental results of equilibrium adsorption for individual metal ion (Cu{sup 2+}, Co{sup 2+}, Ni{sup 2+}) on chitosan bead. Adsorption strength of metal ions decreased in the order of Cu{sup 2+}>Co{sup 2+}>Ni{sup 2+} ion. Breakthrough curves of single and multicomponent adsorption for metal ions were obtained from the experimental results of fixed-bed adsorption. The breakthrough curves were analyzed by simulation with fixed-bed adsorption equation based on LDFA (linear driving force approximation) adopted LAS (ideal adsorbed solution) theory which can predict multi-component adsorption isotherm from individual adsorption isotherm. The behavior of fixed bed adsorption for single and multi-component system could be nicely simulated by the equation. 22 refs., 10 figs., 2 tabs.

  8. The dynamic adsorption of Xe on a fixed bed adsorber at 77 K

    CERN Document Server

    Long, Bin; Wang, Qun- Shu; Feng, Shu- Juan; Zhou, Guo- Qing; Feng, Tian- Cheng; Tian, Yan- Jie; Ma, Huai- Cheng

    2016-01-01

    During the design of fixed bed adsorbers, it is vital to understand the dynamic adsorption properties of the system. Because temperature is one of the most important factors affecting adsorbent performance, such that the dynamic adsorption coefficients tend to increase as the temperature decreases, the dynamic adsorption characteristics of Xe on a fixed bed adsorber at 77 K were studied in the present work to minimize the volume of fixed bed adsorber, employing a variety of adsorbents under different operational conditions. The results show that the adsorption performance of carbon molecular sieve is superior to that of activated carbon. And both operational conditions and the presence of gaseous impurities were found to affect adsorption properties.

  9. Expanded bed adsorption of bromelain (E.C. 3.4.22.33) from Ananas comosus crude extract

    OpenAIRE

    Silveira, E.; M. E. Souza-Jr; J. C. C. Santana; A. C. Chaves; L. F. Porto; E. B. Tambourgi

    2009-01-01

    This work focuses on the adsorption of Bromelain in expanded bed conditions, such as the adsorption kinetics parameters. The adsorption kinetics parameters showed that after 40 minutes equilibrium was achieved and maximum adsorption capacity was 6.11 U per resin mL. However, the maximum adsorption capacity was only determined by measuring the adsorption isotherm. Only by the Langmuir model the maximum adsorption capacity, Qm, and dissociation constant, kd, values could be estimated as 9.18 U/...

  10. The adsorption of copper in a packed-bed of chitosan beads: Modeling, multiple adsorption and regeneration

    OpenAIRE

    Neomagus, Hein W J P; Osifo, Peter O; Everson, Raymond C.; Webster, Athena; Gun, Marius A

    2009-01-01

    In this study, exoskeletons of Cape rock lobsters were used as raw material in the preparation of chitin that was successively deacetylated to chitosan flakes. The chitosan flakes were modified into chitosan beads and the beads were cross-linked with glutaraldehyde in order to study copper adsorption and regeneration in a packed-bed column. Five consecutive adsorption and desorption cycles were carried out and a chitosan mass loss of 25% was observed, after the last cycle. Despite the loss of...

  11. Design of expanded bed supports for the recovery of plasmid DNA by anion exchange adsorption

    DEFF Research Database (Denmark)

    Theodossiou, Irini; Søndergaard, M.; Thomas, Owen R. T.

    2001-01-01

    In this study we detail the rational design of new chromatographic adsorbents tailored for the capture of plasmid DNA. Features present on current chromatographic supports that can significantly enhance plasmid binding capacity have been identified in packed bed chromatography experiments...

  12. Single-step Purification of Molecular Chaperone GroEL by Expanded Bed Chromatography

    Institute of Scientific and Technical Information of China (English)

    佟晓冬; 杨征; 董晓燕; 孙彦

    2003-01-01

    Expanded bed adsorption (EBA) is an integrative downstream processing technique for the purification of biological substances directly from unclarified feedstock. In this study, molecular chaperone GroEL, an important protein folding helper both in vivo and in vitro, was purified by the single-step EBA technique from the unclarified homogenate of recombinant E. coli cells. Compared with packed bed adsorption, the EBA technique provided a single-step approach to yield an electrophoretic purity of GroEL. After the homogenate loading and column washing in the expanded bed mode, the GroEL protein was recovered by stepwise salt-gradient elution in packed-bed or expanded-bed modes, respectively. The expanded-bed elution mode was found as efficient as the packed-bed mode in the purification of GroEL from cell disruptate.

  13. Parameters estimation for amino acids adsorption in a fixed bed by moment analysis

    Directory of Open Access Journals (Sweden)

    M.A. Cremasco

    2001-06-01

    Full Text Available Equilibrium constant and mass transfer parameters are needed for the study of amino acid separation in any process involving adsorption in fixed beds. The adsorption constants, effective diffusion coefficients, and axial dispersion coefficients for two amino acids, L-phenylalanine (Phe and L-tyrosine (Tyr, are determined from a series of pulse tests in a fixed bed packed with PVP (poly-4-vinylpyridine resin. Total bed voidage at different flow rates is estimated from NaCl pulse test data. The effective pore diffusivities of Phe, Tyr, and NaCl are estimated from moment analysis of pulse data. A detailed rate model is then solved numerically and adsorption constants, effective diffusion coefficients, axial dispersion coefficients are determined by moment analysis and compared with the pulse data. The advantage of this method is that the effective intraparticle diffusivities can be determined without the influence of extracolumn dispersion or intracolumn axial dispersion effects.

  14. A new fluid distribution system for scale-flexible expanded bed adsorption

    DEFF Research Database (Denmark)

    Hubbuch, Jürgen; Heebøll-Nielsen, Anders; Hobley, Timothy John;

    2002-01-01

    A new fluid distribution system designed for expanded bed adsorption was introduced and studied in a 150-cm diameter column. Based on fluid application through a rotating distributor, it eradicates the need for perforated plates, meshes, or local mixers. The effect of rotation rate on column...... performance was examined by fluidizing a 30-cm high bed of supports with tap water and introducing pulses of dye or acetone tracer. Linear bed expansion was seen as the superficial fluid velocity raised from 170 cm (.) h(-1) to 450 cm (.) h(-1) (3000 L (.) h(-1) to 8000 L (.) h(-1)), and there was little...... change in expansion characteristics as distributor rotation rate was increased from 2.5 to 10 rpm. The distributor was observed to generate a flow pattern suitable for expanded bed adsorption when the supports were fluidized at a superficial fluid velocity of 283 cm (.) h(-1) and dye pulses introduced...

  15. Fixed-bed adsorption study of methylene blue onto pyrolytic tire char

    Science.gov (United States)

    Makrigianni, Vassiliki; Giannakas, Aris; Papadaki, Maria; Albanis, Triantafyllos; Konstantinou, Ioannis

    2016-04-01

    In this work, the adsorption efficiency of acid treated pyrolytic tire char to cationic methylene blue (MB) dye adsorption from aqueous solutions was investigated by fixed-bed adsorption column experiments. The effects of the initial dye concentration (10 - 40 mg L-1) and feed flow rate (50 - 150 mL min -1) with a fixed bed height (15 cm) were studied in order to determine the breakthrough characteristics of the adsorption system. The Adams-Bohart, Yoon-Nelson and Thomas model were applied to the adsorption of MB onto char at different operational conditions to predict the breakthrough curves and to determine the characteristic parameters of the column. The results showed that the maximum adsorbed quantities decreased with increasing flow rate and increased with increasing initial MB concentration. Breakthrough time and exhaustion time increased with decreasing inlet dye concentration and flow rate. In contrast with Adams-Bohart model, Yoon-Nelson model followed by Thomas model were found more suitable to describe the fixed-bed adsorption of methylene blue by char. The correlation coefficient values R2 for both models at different operating conditions are higher than 0.9 and the low average relative error values provided very good fittings of experimental data at different operating conditions. Higher adsorption capacity of 3.85 mg g -1 was obtained at 15 cm of adsorbent bed height, flow rate of 100 mL min -1and initial MB concentration of 40 mg L-1. Although that activated carbons exhibited higher adsorption capacities in the literature, acid-treated pyrolytic tire char was found to be considerably efficient adsorbent for the removal of MB dye column taking into account the advantages of the simpler production process compared to activated carbons, as well as, the availability of waste tire feedstock and concurrent waste tire management.

  16. Cryogenic Adsorption of Low-concentration Hydrogen on 5A Molecular Sieve Bed

    Institute of Scientific and Technical Information of China (English)

    LIU; Zhen-xing; YANG; Hong-guang; XIA; Ti-rui; ZHAN; Qin; YANG; Li-ling

    2013-01-01

    The separation of low-concentration hydrogen isotopes from helium is a processing step that is required for ceramic lithium breeding blanket processing.In this study,the adsorption of low-concentration hydrogen from helium carrier was measured using 5A molecular sieve fixed bed in the cryogenic condition.The adsorption performances of hydrogen on 5A molecular sieve were discussed.The effect of the different

  17. Simulated moving bed chromatography for the separation of ethyl esters of eicosapentaenoic acid and docosahexaenoic acid under nonlinear conditions.

    Science.gov (United States)

    Li, Min; Bao, Zongbi; Xing, Huabin; Yang, Qiwei; Yang, Yiwen; Ren, Qilong

    2015-12-18

    In this study, ethyl esters of eicosapentaenoic acid and docosahexaenoic acid were separated with simulated moving bed (SMB) chromatography, where the stationary phase was C18 silica gel with particle size of 10μm packed in eight columns, and the mobile phase was pure methanol. The Henry constants, transport parameters and total porosity were measured from pulse response chromatographic experiments using a single column. The Henry constants were obtained from the first moment analysis. The transport parameters including axial dispersion coefficients and effective mass transfer coefficients were obtained from the second moment analysis. Nonlinear adsorption equilibrium isotherms for the pure components and their mixture were determined from adsorption-desorption method. The Langmuir model was used to fit the experimental data, and the corresponding parameters were further used to predict the competitive adsorption equilibria of the mixture. The validity of mathematical model parameters was checked by a frontal chromatography experiment. The simulated results of the SMB process using these parameters agreed well with the experimental results. At the feed concentration of 100g/L, the SMB separation was able to produce both solutes with relative purity above 99%, productivity of 13.11g/L adsorbent/h, and solvent consumption of 0.46L/g. PMID:26620595

  18. Searching for Measures of Reversibility in Continuous Adsorption through Packed Bed Columns

    Science.gov (United States)

    Sidiras, Dimitris K.

    2009-08-01

    This work deals with searching for measures of after-process reversibility in continuous adsorption through packed bed columns. A methodology has been designed/developed under the form of an algorithmic procedure including 17 activity stages and 5 decision nodes. An implementation is presented concerning adsorption/desorption of methylene blue on pine sawdust. An Ideal Reversibility Index (IRI) and two Real Rreversibility Indices (RRIs) have been estimated after fitting kinetic adsorption/desorption models to experimental data. Last, the implications of applying an innovation are discussed in terms of techno-economic analysis.

  19. Single - and multi-component liquid phase adsorption measurements by headspace chromatography

    Directory of Open Access Journals (Sweden)

    A.E.B. Torres

    2001-03-01

    Full Text Available This short communication presents a new technique for evaluation of adsorption equilibrium in the liquid phase using headspace chromatography. The technique may be used in two different modes: single-component equilibrium (the "finite bath" mode and the multicomponent selectivity mode. Illustrative experimental results are presented for xylenes adsorption on Y zeolite pellets.

  20. Pressure-flow relationships for packed beds of compressible chromatography media at laboratory and production scale.

    Science.gov (United States)

    Stickel, J J; Fotopoulos, A

    2001-01-01

    Pressure drop across chromatography beds employing soft or semirigid media can be a significant problem in the operation of large-scale preparative chromatography columns. The shape or aspect ratio (length/diameter) of a packed bed has a significant effect on column pressure drop due to wall effects, which can result in unexpectedly high pressures in manufacturing. Two types of agarose-based media were packed in chromatography columns at various column aspect ratios, during which pressure drop, bed height, and flow rate were carefully monitored. Compression of the packed beds with increasing flow velocities was observed. An empirical model was developed to correlate pressure drop with the aspect ratio of the packed beds and the superficial velocity. Modeling employed the Blake-Kozeny equation in which empirical relationships were used to predict bed porosity as a function of aspect ratio and flow velocity. Model predictions were in good agreement with observed pressure drops of industrial scale chromatography columns. A protocol was developed to predict compression in industrial chromatography applications by a few laboratory experiments. The protocol is shown to be useful in the development of chromatographic methods and sizing of preparative columns.

  1. ECONOMIC ANALYSIS OF SELECTED ADSORPTION BEDS USED FOR WATER TREATMENT

    Directory of Open Access Journals (Sweden)

    Iwona Skoczko

    2016-02-01

    Full Text Available In the paper an economic analysis of the sorption deposits used for water purification was performed. Such masses of carbon as Organosorb 10 deposit, Norit ROW 0.8 Supra deposit, Hydroantracyt N deposit and K110 deposit were selected. The economic substantiation for the selection of specific deposits was based on the purchase cost of filter deposits, the environmental fee for water intake, the cost of equipment to aerate water, the cost of chemicals for deposits regeneration, the cost of the dosing pump reagents for regeneration generated during the process of adsorption using each of the deposits selected to the analysis. K110 deposit turned out to be the cheapest in the exploitation and Norit ROW 0.8 Supra was most expensive. The operating costs of the adsorption deposits depend mainly on the purchase of the adsorbent and the speed of adsorption. Moreover, environmental fee for water intake constitutes a significant share in the costs of exploitation of carbon deposits , which is greater than the deposit costs.

  2. Expanded bed adsorption/desorption of proteins with Streamline Direct CST I adsorbent.

    Science.gov (United States)

    Li, Ping; Xiu, Guohua; Mata, Vera G; Grande, Carlos A; Rodrigues, Alirio E

    2006-08-20

    Streamline Direct CST I is a new type of ion exchanger with multi-modal functional groups, specially designed for an expanded bed adsorption (EBA) process, which can capture directly the proteins from the high ionic strength feedstocks with a high binding capacity. In this study, an experimental study is carried out for two-component proteins (BSA and myoglobin) competitive adsorption and desorption in an expanded bed packed with Streamline Direct CST I. Based on the measurements of the single- and two-component bovine serum albumin (BSA)/myoglobin adsorption isotherm on Streamline Direct CST I, the binding and elution conditions for the whole EBA process are selected; and then frontal analysis for a longer timescale and column displacement experiments in a fixed bed (XK16/20 column) are carried out to evaluate the two-component proteins (BSA and myoglobin) competitive adsorption and displacement on Streamline Direct CST I. Finally, the feasibility of capturing both BSA and myoglobin by an expanded bed packed with Streamline Direct CST I is addressed in a Streamline 50 column packed with 300 mL Streamline Direct CST I. PMID:16572450

  3. Expanded-bed adsorption utilizing ion-exchange resin to purify extracellular beta-galactosidase.

    Science.gov (United States)

    Pereira, J A; Vieira E Rosa, P De T; Pastore, G M; Santana, C C

    1998-01-01

    The application of expanded-bed ion-exchange resins allows the elimination of intermediary particulate separation steps like filtration or centrifugation prior to adsorption steps in enzyme-purification processes from crude fermentation broths. This work is concerned with the experimental evaluation data of a process related to the adsorption of an extracellular p-galactosidase from the fungi Scopulariopsis. The protein recovery in the ion-exchange resin Accell Plus QMA was accomplished using a continuous-monitoring method. The direct adsorption step was followed by a elution step with concentrated NaCl solutions aiming to improve the enzyme-specific activity. Experimental data for fixed and expanded bed were compared.

  4. Entropy generation analysis of two-bed, silica gel-water, non-regenerative adsorption chillers

    Science.gov (United States)

    Chua, H. T.; Ng, K. C.; Malek, A.; Kashiwagi, T.; Akisawa, A.; Saha, B. B.

    1998-06-01

    The current thrust on the use of environmentally friendly technologies for cooling applications, inter alia, envisages the adoption of adsorption systems. Adsorption chillers are known to be `inefficient' due to their low coefficient of performance. Although the basic physics of heat and mass transfer in various components of the system is well understood, there is a lacuna in the quantification of irreversibilities. In this paper, a silica gel-water, two-bed, non-regenerative chiller is analysed. It is shown that the largest cycle-averaged rate of entropy generation is in the beds and that the least is in the condenser. The entropy generation rates in the beds are further studied, showing that the maximum contribution is made during the switching phase. In general, manufacturers' effort to maximize cooling capacity is shown to correspond to maximum entropy generation in the evaporator.

  5. Dynamic modeling of fixed-bed adsorption of flue gas using a variable mass transfer model

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jehun; Lee, Jae W. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2016-02-15

    This study introduces a dynamic mass transfer model for the fixed-bed adsorption of a flue gas. The derivation of the variable mass transfer coefficient is based on pore diffusion theory and it is a function of effective porosity, temperature, and pressure as well as the adsorbate composition. Adsorption experiments were done at four different pressures (1.8, 5, 10 and 20 bars) and three different temperatures (30, 50 and 70 .deg. C) with zeolite 13X as the adsorbent. To explain the equilibrium adsorption capacity, the Langmuir-Freundlich isotherm model was adopted, and the parameters of the isotherm equation were fitted to the experimental data for a wide range of pressures and temperatures. Then, dynamic simulations were performed using the system equations for material and energy balance with the equilibrium adsorption isotherm data. The optimal mass transfer and heat transfer coefficients were determined after iterative calculations. As a result, the dynamic variable mass transfer model can estimate the adsorption rate for a wide range of concentrations and precisely simulate the fixed-bed adsorption process of a flue gas mixture of carbon dioxide and nitrogen.

  6. Fixed Bed Adsorption of Drugs on Silica Aerogel from Supercritical Carbon Dioxide Solutions

    Directory of Open Access Journals (Sweden)

    Giuseppe Caputo

    2013-01-01

    Full Text Available Supercritical adsorption coupled with the high adsorption capacity of silica aerogel allows the preparation of a new kind of delivery systems of poor water soluble drugs. In order to overcome drawbacks of conventional techniques where the use of liquid solvents can cause the fracture of aerogel porous structure, in this work a new adsorption process of drugs from a supercritical mixture is proposed. Adsorption takes place from a fluid solution of the drug in supercritical CO2 and ethanol as cosolvent. A fixed bed adsorption plant has been developed to allow fast mixing of fluid phase and effective contact in the adsorption column. The use of ethanol as cosolvent allows to overcome the limitation of supercritical adsorption due to low solubility of many drugs in supercritical CO2. Adsorption isotherms were measured for one-model substance, nimesulide, at 40°C, and breakthrough curve was experimentally obtained. The drug loading of the drug into silica aerogel was up to 9 wt%. The drug composite was characterized using scanning electron microscopy, and release kinetics of the adsorbed drug were also evaluated by in vitro dissolution tests. The dissolution of nimesulide from loaded aerogel is much faster than dissolution of crystalline nimesulide. Around 80% of nimesulide dissolves from the aerogel within 6 minutes, whereas dissolving 80% of the crystalline drug takes about 90 min.

  7. Critical conditions of polymer adsorption and chromatography on non-porous substrates.

    Science.gov (United States)

    Cimino, Richard T; Rasmussen, Christopher J; Brun, Yefim; Neimark, Alexander V

    2016-07-15

    We present a novel thermodynamic theory and Monte Carlo simulation model for adsorption of macromolecules to solid surfaces that is applied for calculating the chain partition during separation on chromatographic columns packed with non-porous particles. We show that similarly to polymer separation on porous substrates, it is possible to attain three chromatographic modes: size exclusion chromatography at very weak or no adsorption, liquid adsorption chromatography when adsorption effects prevail, and liquid chromatography at critical conditions that occurs at the critical point of adsorption. The main attention is paid to the analysis of the critical conditions, at which the retention is chain length independent. The theoretical results are verified with specially designed experiments on isocratic separation of linear polystyrenes on a column packed with non-porous particles at various solvent compositions. Without invoking any adjustable parameters related to the column and particle geometry, we describe quantitatively the observed transition between the size exclusion and adsorption separation regimes upon the variation of solvent composition, with the intermediate mode occurring at a well-defined critical point of adsorption. A relationship is established between the experimental solvent composition and the effective adsorption potential used in model simulations. PMID:27089017

  8. Simulation of a high efficiency multi-bed adsorption heat pump

    International Nuclear Information System (INIS)

    Attaining high energy efficiency with adsorption heat pumps is challenging due to thermodynamic losses that occur when the sorbent beds are thermally cycled without effective heat recuperation. The multi-bed concept described here enables high efficiency by effectively transferring heat from beds being cooled to beds being heated. A simplified lumped-parameter model and detailed finite element analysis are used to simulate a sorption compressor, which is used to project the overall heat pump coefficient of performance. Results are presented for ammonia refrigerant and a nano-structured monolithic carbon sorbent specifically modified for the application. The effects of bed geometry and number of beds on system performance are explored, and the majority of the performance benefit is obtained with four beds. Results indicate that a COP of 1.24 based on heat input is feasible at AHRI standard test conditions for residential HVAC equipment. When compared on a basis of primary energy input, performance equivalent to SEER 13 or 14 are theoretically attainable with this system. - Highlights: ► A multi-bed concept for adsorption heat pumps is capable of high efficiency. ► Modeling is used to simulate sorption compressor and overall heat pump performance. ► Results are presented for ammonia refrigerant and a nano-structured monolithic carbon sorbent. ► The majority of the efficiency benefit is obtained with four beds. ► Predicted COP as high as 1.24 for cooling is comparable to SEER 13 or 14 for electric heat pumps.

  9. 5-Aminobenzimidazole as new hydrophobic charge-induction ligand for expanded bed adsorption of bovine IgG.

    Science.gov (United States)

    Shi, Wei; Lin, Dong-Qiang; Tong, Hong-Fei; Yun, Jun-Xian; Yao, Shan-Jing

    2015-12-18

    Expanded bed adsorption (EBA) can capture target proteins directly from unclarified feedstock without prior solid-liquid separation. Hydrophobic charge-induction chromatography (HCIC) is a promising technology for biomolecule separation with high capacity, good selectivity and relatively low cost without the pretreatment of dilution or salt addition. In this work, EBA and HCIC were combined to develop a new separation technology, hydrophobic charge-induction EBA. Two HCIC ligands, 4-mercapto-ethyl-pyridine (MEP) and 5-aminobenzimidazole (ABI), were coupled onto agarose beads containing tungsten carbide to prepare the resins for EBA, named T-MEP and T-ABI, respectively. The static adsorption and dynamic binding behaviors of bovine IgG (bIgG) were investigated. Two resins had similar saturated adsorption capacities and salt-tolerant properties, but T-ABI showed higher dynamic binding capacity than T-MEP, indicating that ABI ligand was more suitable for EBA. The performances in expanded bed were verified. With the protein mixture (2mg/ml bIgG and 10mg/ml bovine serum albumin) as the model feedstock, the effects of loading and elution pH, expansion factor and loading volume on the separation performance of bIgG were evaluated. Finally, T-ABI EBA was used to separate bIgG directly from bovine whey with optimized operation conditions. The purity and recovery of bIgG reached 90.6% and 78.2%, respectively. The purification factor was about 19.3. The results demonstrated that the combination of HCIC and EBA would be a potential platform for antibody capture with less feedstock pretreatments, high efficiency and relatively low cost. PMID:26585208

  10. Modeling and Experimental Studies of Mercury Oxidation and Adsorption in a Fixed-Bed Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Buitrago, Paula A.; Morrill, Mike; Lighty, JoAnn S.; Silcox, Geoffrey D.

    2009-06-15

    This report presents experimental and modeling mercury oxidation and adsorption data. Fixed-bed and single-particle models of mercury adsorption were developed. The experimental data were obtained with two reactors: a 300-W, methane-fired, tubular, quartz-lined reactor for studying homogeneous oxidation reactions and a fixed-bed reactor, also of quartz, for studying heterogeneous reactions. The latter was attached to the exit of the former to provide realistic combustion gases. The fixed-bed reactor contained one gram of coconut-shell carbon and remained at a temperature of 150°C. All methane, air, SO2, and halogen species were introduced through the burner to produce a radical pool representative of real combustion systems. A Tekran 2537A Analyzer coupled with a wet conditioning system provided speciated mercury concentrations. At 150°C and in the absence of HCl or HBr, the mercury uptake was about 20%. The addition of 50 ppm HCl caused complete capture of all elemental and oxidized mercury species. In the absence of halogens, SO2 increased the mercury adsorption efficiency to up to 30 percent. The extent of adsorption decreased with increasing SO2 concentration when halogens were present. Increasing the HCl concentration to 100 ppm lessened the effect of SO2. The fixed-bed model incorporates Langmuir adsorption kinetics and was developed to predict adsorption of elemental mercury and the effect of multiple flue gas components. This model neglects intraparticle diffusional resistances and is only applicable to pulverized carbon sorbents. It roughly describes experimental data from the literature. The current version includes the ability to account for competitive adsorption between mercury, SO2, and NO2. The single particle model simulates in-flight sorbent capture of elemental mercury. This model was developed to include Langmuir and Freundlich isotherms, rate equations, sorbent feed rate, and

  11. Adsorption-induced deformation in porous media and application to CO2-injected coal beds

    Science.gov (United States)

    Vandamme, M.; Brochard, L.; Coussy, O.

    2010-05-01

    An injection of carbon dioxide into a coal bed methane reservoir facilitates the recovery of methane, a process known as enhanced coal bed methane recovery (ECBM). Over the injection process carbon dioxide molecules get adsorbed at the surface of the coal pores, making the coal swell. This swelling leads to a closure of the coal fracture system and thus to a decrease of the permeability of the reservoir, hindering further injection and impairing the economic viability of ECBM. Here we provide a framework in which to calculate adsorption-induced strains in a porous medium. Usual poromechanics equations are extended to take into account surface energies. The calculations performed are valid for a general microstructure and the microstructural features are identified which govern the mechanical response of the porous medium to a change of surface stress. The effect of adsorption on surface stress is also discussed. An application to coal beds is presented. We employ molecular simulations to calculate adsorption isotherms of methane and carbon dioxide in coal. A comparison of our results with experimental data on coal swelling shows that adsorption in micropores (below 2 nm) plays a primary role in the swelling behavior of coal.

  12. Adsorption of zinc ions on bone char using helical coil-packed bed columns and its mass transfer modeling

    DEFF Research Database (Denmark)

    Moreno-Pérez, J.; Bonilla-Petriciolet, A.; Rojas-Mayorga, C. K.;

    2016-01-01

    This study reports the assessment of helical coil-packed bed columns for Zn2+ adsorption on bone char. Zn2+ adsorption breakthrough curves have been obtained using helical coil columns with different characteristics and a comparison has been conducted with respect to the results of straight fixed......-bed columns. Results showed that the helical coil adsorption columns may offer an equivalent removal performance than that obtained for the traditional packed bed columns but using a compact structure. However, the coil diameter, number of turns, and feed flow appear to be crucial parameters for obtaining...... the best performance in this packed-bed geometry. A mass transfer model for a mobile fluid flowing through a porous media was used for fitting and predicting the Zn2+ breakthrough curves in helical coil bed columns. Results of adsorbent physicochemical characterization showed that Zn2+ adsorption on bone...

  13. Simulated moving-bed adsorption for separation of racemic mixtures

    Directory of Open Access Journals (Sweden)

    Santos M. A. G.

    2004-01-01

    Full Text Available The two enantiomers that constitute a racemate have different activities when employed as pharmaceuticals. Due to this fact, fully recognized today, the pharmaceutical industry has been forced to market pure enantiomers instead of the racemic mixture whenever a chiral compound is involved. The simulated moving bed (SMB is a chromatographic process that, unlike traditional HPLC systems, operates continuously without losing the enantiomeric purity of the outlet streams. The present work describes the enantioseparation of the anesthetic ketamine in a semipreparative-scale SMB unit. The chiral stationary phase employed was the microcrystalline cellulose triacetate. The outlet streams were analyzed by an on-line system, composed by an UV/VIS meter and a polarimeter, and also by HPLC. The analysis indicated purity values up to 100% for the stream of interest and up to 97.7% for the other stream.

  14. 扩张床吸附剂:制备及功能化%Adsorbents for Expanded Bed Adsorption: Preparation and Functionalization

    Institute of Scientific and Technical Information of China (English)

    赵珺; 姚善泾; 林东强

    2009-01-01

    Expanded bed adsorption (EBA), a promising and practical separation technique, has been widely stud-ied in the past two decades. The development of adsorbents for EBA process is a challenging course, with the spe-cial design and preparation according to the target molecules and specific expanded bed systems. Many types of supporting matrices for expanded bed adsorbents have been developed, and their preparation methods are being consummated gradually. These matrices are activated and then coupled with ligands to form functionalized adsorb-ents, including ion-exchange adsorbents, affinity adsorbents, mixed mode adsorbents, hydrophobic charge induction chromatography adsorbents and others. In this review, the preparation of the matrices for EBA process is summa-rized, and the coupling of ligands to the matrices to prepare functionalized adsorbents is discussed as well.

  15. Deep Bed Adsorption Testing using Silver-Functionalized Aerogel

    Energy Technology Data Exchange (ETDEWEB)

    Nick Soelberg; Tony Watson

    2012-06-01

    Nuclear fission results in the production of fission products and activation products, some of which tend to be volatile during used fuel reprocessing and evolve in gaseous species into the reprocessing facility off-gas systems. Analyses have shown that I129, due to its radioactivity, high potential mobility in the environment, and high longevity (half life of 15.7 million years), can require control efficiencies of up to 1,000x or higher to meet regulatory emission limits. Two Aerogel sorption tests that have been performed this fiscal year. The maximum iodine decontamination factor (DF) was measured to be over 10,000, above the 1,000-10,000 target DF range. The mass transfer zone may be as short as 0.5 inches under the sorption conditions of the first test. Only a small fraction of the iodine sorbed on Bed 1 was desorbed during the purge periods. The silver-functionalized Aerogel appears to have potential to be a very effective and efficient iodine sorbent.

  16. Experimental Investigation of a Three-Bed Adsorption Refrigeration Chiller Employing an Advanced Mass Recovery Cycle

    OpenAIRE

    Atsushi Akisawa; Yuki Ueda; Aep Saepul Uyun; Takahiko Miyazaki

    2009-01-01

    The performance of an advanced three-bed adsorption chiller with a mass recovery cycle has been experimentally investigated in the present study. The temperature and pressure of various components of the chiller were monitored to observe the dynamic behaviour of the chiller. The performances in terms of the coefficient of performance (COP) and specific cooling power (SCP) were compared with a conventional single stage. The results show that the proposed cycle produces COP and SCP values super...

  17. Effects of Pulse Ultrasound on Adsorption of Geniposide on Resin 1300 in a Fixed Bed

    Institute of Scientific and Technical Information of China (English)

    陆向红; 徐之超; 计建炳

    2011-01-01

    The effects of pulse ultrasound with different pulse parameters on the breakthrough curves of Geniposide on Resin 1300 were studied. The mass transfer model describing the adsorption process was constructed. Adsorption capability and the overall mass-transfer coefficient were obtained by fitting the constructed mass-transfer model and the experimental data. The effects of pulse ultrasound on adsorption of Geniposide on Resin1300 in a fixed bed were studied and compared. Amount of Geniposide adsorbed on Resin 1300 in the presence of ultrasound is lower than that in the absence of ultrasound, but the mass-transfer rate with ultrasonic irradiation is higher than that without ultrasound. Furthermore, mass transfer rate is enhanced by pulse modulation. In the conditions studied, the adsorption equilibrium constant decreases with increasing ultrasonic power, while the overall mass-transfer co-efficient increases. With increasing pulse duty ratio, adsorption equilibrium constant decreases initially, reaches a minimum when pulse duty ratio is 0.5, and then increases. On the contrary, the overall mass-transfer coefficient in-creases initially and reaches a maximum when pulse ratio is 0.5, and then decreases. Effects of pulse period on ad-sorption equilibrium and mass transfer rate reached the peak at pulse period of 28.6 ms.

  18. The adsorption of copper in a packed-bed of chitosan beads: modeling, multiple adsorption and regeneration.

    Science.gov (United States)

    Osifo, Peter O; Neomagus, Hein W J P; Everson, Raymond C; Webster, Athena; vd Gun, Marius A

    2009-08-15

    In this study, exoskeletons of Cape rock lobsters were used as raw material in the preparation of chitin that was successively deacetylated to chitosan flakes. The chitosan flakes were modified into chitosan beads and the beads were cross-linked with glutaraldehyde in order to study copper adsorption and regeneration in a packed-bed column. Five consecutive adsorption and desorption cycles were carried out and a chitosan mass loss of 25% was observed, after the last cycle. Despite the loss of chitosan material, an improved efficiency in the second and third cycles was observed with the adsorbent utilizing 97 and 74% of its adsorbent capacity in the second and third cycles, respectively. The fourth and fifth cycles, however, showed a decreased efficiency, and breakage of the beads was observed after the fifth cycle. In the desorption experiments, 91-99% of the adsorbed copper was regenerated in the first three cycles. It was also observed that the copper can be regenerated at a concentration of about a thousand fold the initial concentration. The first cycle of adsorption could be accurately described with a shrinking core particle model combined with a plug flow column model. The input parameters for this model were determined by batch characterization methods, with as only fitting parameter, the effective diffusion coefficient of copper in the bead. PMID:19321260

  19. The adsorption of copper in a packed-bed of chitosan beads: Modeling, multiple adsorption and regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Osifo, Peter O., E-mail: petero@vut.ac.za [Department of Chemical Engineering, Vaal University of Technology, P/Bag X021, Vanderbijlpark 1900 (South Africa); Neomagus, Hein W.J.P.; Everson, Raymond C. [School of Chemical and Minerals Engineering, North-West University, P/Bag X6001, Potchefstroom 2520 (South Africa); Webster, Athena [University of Utah, Chemistry Department, Salt Lake City, UT 84112 (United States); Gun, Marius A. vd [Sulzer Elbar B.V., Spikweien 36, NL-5943 AD Lomm (Netherlands)

    2009-08-15

    In this study, exoskeletons of Cape rock lobsters were used as raw material in the preparation of chitin that was successively deacetylated to chitosan flakes. The chitosan flakes were modified into chitosan beads and the beads were cross-linked with glutaraldehyde in order to study copper adsorption and regeneration in a packed-bed column. Five consecutive adsorption and desorption cycles were carried out and a chitosan mass loss of 25% was observed, after the last cycle. Despite the loss of chitosan material, an improved efficiency in the second and third cycles was observed with the adsorbent utilizing 97 and 74% of its adsorbent capacity in the second and third cycles, respectively. The fourth and fifth cycles, however, showed a decreased efficiency, and breakage of the beads was observed after the fifth cycle. In the desorption experiments, 91-99% of the adsorbed copper was regenerated in the first three cycles. It was also observed that the copper can be regenerated at a concentration of about a thousand fold the initial concentration. The first cycle of adsorption could be accurately described with a shrinking core particle model combined with a plug flow column model. The input parameters for this model were determined by batch characterization methods, with as only fitting parameter, the effective diffusion coefficient of copper in the bead.

  20. DNA binding during expanded bed adsorption and factors affecting adsorbent aggregation

    DEFF Research Database (Denmark)

    Arpanaei, Ayyoob; Mathiasen, N.; Hobley, Timothy John

    2008-01-01

    tolerance of anion exchangers when binding DNA. However, more importantly. with the adsorbents examined here. attempts to reduce bed aggregation by feedstock conditioning with added salt may increase DNA binding leading to a reduction in expanded bed adsorption performance compromising protein capture...... ligand densities to be examined. Very high dynamic binding capacities at 10% breakthrough were found in the absence of added salt. However, the highest binding capacities (similar to 10 and similar to 19mg DNA ml(-1) gel) were found in buffers containing added salt at concentrations of either 0.25 or 0......) even though the dynamic binding capacity was reduced as DNA concentration was increased. The extent of bed contraction during DNA loading was found to be a function of added salt concentration and ligand density of the adsorbent. The results imply that ligand density significantly affects the salt...

  1. Mechanisms of chain adsorption on porous substrates and critical conditions of polymer chromatography.

    Science.gov (United States)

    Cimino, Richard T; Rasmussen, Christopher J; Brun, Yefim; Neimark, Alexander V

    2016-11-01

    Polymer adsorption is a ubiquitous phenomenon with numerous technological and healthcare applications. The mechanisms of polymer adsorption on surfaces and in pores are complex owing to a competition between various entropic and enthalpic factors. Due to adsorption of monomers to the surface, the chain gains in enthalpy yet loses in entropy because of confining effects. This competition leads to the existence of critical conditions of adsorption when enthalpy gain and entropy loss are in balance. The critical conditions are controlled by the confining geometry and effective adsorption energy, which depends on the solvent composition and temperature. This phenomenon has important implications in polymer chromatography, since the retention at the critical point of adsorption (CPA) is chain length independent. However, the mechanisms of polymer adsorption in pores are poorly understood and there is an ongoing discussion in the theoretical literature about the very existence of CPA for polymer adsorption on porous substrates. In this work, we examine the mechanisms of chain adsorption on a model porous substrate using Monte Carlo (MC) simulations. We distinguish three adsorption mechanisms depending on the chain location: on external surface, completely confined in pores, and also partially confined in pores in so-called "flower" conformations. The free energies of different conformations of adsorbed chains are calculated by the incremental gauge cell MC method that allows one to determine the partition coefficient as a function of the adsorption potential, pore size, and chain length. We confirm the existence of the CPA for chain length independent separation on porous substrates, which is explained by the dominant contributions of the chain adsorption at the external surface, in particular in flower conformations. Moreover, we show that the critical conditions for porous and nonporous substrates are identical and depend only on the surface chemistry. The theoretical

  2. Mechanisms of chain adsorption on porous substrates and critical conditions of polymer chromatography.

    Science.gov (United States)

    Cimino, Richard T; Rasmussen, Christopher J; Brun, Yefim; Neimark, Alexander V

    2016-11-01

    Polymer adsorption is a ubiquitous phenomenon with numerous technological and healthcare applications. The mechanisms of polymer adsorption on surfaces and in pores are complex owing to a competition between various entropic and enthalpic factors. Due to adsorption of monomers to the surface, the chain gains in enthalpy yet loses in entropy because of confining effects. This competition leads to the existence of critical conditions of adsorption when enthalpy gain and entropy loss are in balance. The critical conditions are controlled by the confining geometry and effective adsorption energy, which depends on the solvent composition and temperature. This phenomenon has important implications in polymer chromatography, since the retention at the critical point of adsorption (CPA) is chain length independent. However, the mechanisms of polymer adsorption in pores are poorly understood and there is an ongoing discussion in the theoretical literature about the very existence of CPA for polymer adsorption on porous substrates. In this work, we examine the mechanisms of chain adsorption on a model porous substrate using Monte Carlo (MC) simulations. We distinguish three adsorption mechanisms depending on the chain location: on external surface, completely confined in pores, and also partially confined in pores in so-called "flower" conformations. The free energies of different conformations of adsorbed chains are calculated by the incremental gauge cell MC method that allows one to determine the partition coefficient as a function of the adsorption potential, pore size, and chain length. We confirm the existence of the CPA for chain length independent separation on porous substrates, which is explained by the dominant contributions of the chain adsorption at the external surface, in particular in flower conformations. Moreover, we show that the critical conditions for porous and nonporous substrates are identical and depend only on the surface chemistry. The theoretical

  3. New Momentum and Energy Balance Equations Considering Kinetic Energy Effect for Mathematical Modelling of a Fixed Bed Adsorption Column

    OpenAIRE

    Luberti, Mauro; Kim, Yo Han; Lee, Chang-Ha; Ferrari, Maria-Chiara; Ahn, Hyungwoong

    2015-01-01

    It was aimed to derive rigorous momentum and energy balance equations where the change of kinetic energy in both spatial and temporal domains of a fixed-bed adsorption column was newly taken into account. While the effect of kinetic energy on adsorption column dynamics is negligible in most cases, it can become more and more influential with an adsorption column experiencing a huge pressure drop or with the gas velocity changing abruptly with time and along the column. The rigorous momentum a...

  4. Expanded bed adsorption of bromelain (E.C. 3.4.22.33 from Ananas comosus crude extract

    Directory of Open Access Journals (Sweden)

    E. Silveira

    2009-03-01

    Full Text Available This work focuses on the adsorption of Bromelain in expanded bed conditions, such as the adsorption kinetics parameters. The adsorption kinetics parameters showed that after 40 minutes equilibrium was achieved and maximum adsorption capacity was 6.11 U per resin mL. However, the maximum adsorption capacity was only determined by measuring the adsorption isotherm. Only by the Langmuir model the maximum adsorption capacity, Qm, and dissociation constant, kd, values could be estimated as 9.18 U/mL and 0.591, respectively, at 25 ºC and 0.1 mol/L phosphate buffer pH 7.5. A column made of glass with an inner diameter of 1 cm was used for the expanded bed adsorption (EBA. The residence time was reduced 10 fold by increasing the expansion degree 2.5 times; nonetheless, the plate number (N value was reduced only 2 fold. After adsorption, the bromelain was eluted in packed bed mode, with a downward flow. The purification factor was about 13 fold and the total protein was reduced 4 fold. EBA showed to be feasible for purification of bromelain.

  5. Fluidized-bed adsorption bioreactor for the treatment of groundwater contaminated with solvents at low concentration

    Energy Technology Data Exchange (ETDEWEB)

    Miyares, P.H.; Teeter, C.V.; Martel, C.J.

    1999-01-01

    Volatile organic compounds (VOCs) are a major source of water contamination in the US. They pose a threat to the environment and are a potential hazard to human health. Trichloroethylene (TCE) is the most common of these pollutants. TCE is usually remediated through pumping and treating it, using either air stripping or granular activated carbon. Bioremediation is an alternative treatment that uses microbes to convert hazardous substances into nonhazardous compounds. A fluidized bed adsorption bioreactor is examined here for the treatment of groundwater contaminated at low concentrations. This pilot study showed that the packed adsorbent bed could be loaded in approximately 36 hours at a flow rate of 120 mL/min. The remediation phase of the process took approximately 13 days. The reduction in the TCE concentration in the sorbent during each round indicated that it was being remediated by the microbiological process. Areas that need to be improved are the rate of remediation and the loading capacity of the adsorption beds. Currently, each complete cycle of loading and remediating requires 2 weeks while only mineralizing 58 mg of TCE per column.

  6. Removal of furan and phenolic compounds from simulated biomass hydrolysates by batch adsorption and continuous fixed-bed column adsorption methods.

    Science.gov (United States)

    Lee, Sang Cheol; Park, Sunkyu

    2016-09-01

    It has been proposed to remove all potential inhibitors and sulfuric acid in biomass hydrolysates generated from dilute-acid pretreatment of biomass, based on three steps of sugar purification process. This study focused on its first step in which furan and phenolic compounds were selectively removed from the simulated hydrolysates using activated charcoal. Batch adsorption experiments demonstrated that the affinity of activated charcoal for each component was highest in the order of vanillic acid, 4-hydroxybenzoic acid, furfural, acetic acid, sulfuric acid, and xylose. The affinity of activated charcoal for furan and phenolic compounds proved to be significantly higher than that of the other three components. Four separation strategies were conducted with a combination of batch adsorption and continuous fixed-bed column adsorption methods. It was observed that xylose loss was negligible with near complete removal of furan and phenolic compounds, when at least one fixed-bed column adsorption was implemented in the strategy. PMID:27289057

  7. Physical and Hydrodynamic Properties of Spherical Cellulose—Titanium Dioxide Composite Matrix for Expanded Bed Adsorption

    Institute of Scientific and Technical Information of China (English)

    雷引林; 林东强; 姚善泾; 刘坐镇; 朱自强

    2003-01-01

    Expanded bed adsorption (EBA) has been widely used in industrial downstream bioprocessing,Solid matrix is the principal pillar supporting the successful application of EBA.A novel spherical ceelulose-titanium dioxide composite matrix was prepared through the method of water-in-oil suspension thermal regeneration.Its typical physical properties were wet density 1.18g.cm-3,,diameters in the range of 100-300μm ,porosity 85.5%,and water content 72.3%.Expansion characteristics and liquid mixing performance of the matrix in expanded bed were investigated using water and 10% (by mass )glycerol solution as mobile phases,The results indicate that the custom-assembled matrix has a stable flow hydrodynamics and exhibits the same degree of liquid-phase mixing or column efficiency as the commercially available Streamline adsorbent.

  8. Experimental Investigation of a Three-Bed Adsorption Refrigeration Chiller Employing an Advanced Mass Recovery Cycle

    Directory of Open Access Journals (Sweden)

    Atsushi Akisawa

    2009-07-01

    Full Text Available The performance of an advanced three-bed adsorption chiller with a mass recovery cycle has been experimentally investigated in the present study. The temperature and pressure of various components of the chiller were monitored to observe the dynamic behaviour of the chiller. The performances in terms of the coefficient of performance (COP and specific cooling power (SCP were compared with a conventional single stage. The results show that the proposed cycle produces COP and SCP values superior to those of the conventional single stage cycle for heat source temperature below 75 °C.

  9. Hydrocarbons adsorption on metal trimesate MOFs: Inverse gas chromatography and immersion calorimetry studies

    International Nuclear Information System (INIS)

    Highlights: • Inverse gas chromatography and immersion calorimetry were compared on two MOFs. • Adsorption of seven carbon atoms adsorbates on Cu3(BTC)2 and Fe(BTC) was performed. • Size and polarizability of adsorbates are decisive in the strength of adsorption. • Dispersive interaction of surface free energy depends on the surface area. • Isp is influenced by the chemistry of adsorbates and morphology of the adsorbents. - Abstract: Two commercial metal-organic frameworks, Cu3(BTC)2 and Fe(BTC), have been selected to compare the adsorption parameters obtained on these materials by two different techniques: immersion calorimetry and inverse gas chromatography (IGC), in order to find a relationship between thermodynamic parameters obtained by so different techniques. From comparison between the enthalpy of adsorption obtained from IGC and the enthalpy of immersion, three molecules of the same number of carbon atoms have been selected: n-heptane, methylcyclohexane and toluene. Both by IGC and immersion calorimetry, the interaction is stronger in Fe(BTC), being the aromaticity of TOL determinant in the strength of the interaction. However, splitting of the enthalpy of adsorption into the dispersive and specific components allows to deduce that both parameters are more important on the Cu3(BTC)2, due to the higher available surface area in the case of the dispersive interaction; and for the specific interaction, due to the high potential of interaction into the micropores

  10. Hydrocarbons adsorption on metal trimesate MOFs: Inverse gas chromatography and immersion calorimetry studies

    Energy Technology Data Exchange (ETDEWEB)

    Gutiérrez, Inés; Díaz, Eva; Vega, Aurelio [Department of Chemical and Environmental Engineering, University of Oviedo, Faculty of Chemistry, Julián Clavería s/n, 33006 Oviedo (Spain); Ordóñez, Salvador, E-mail: sordonez@uniovi.es [Department of Chemical and Environmental Engineering, University of Oviedo, Faculty of Chemistry, Julián Clavería s/n, 33006 Oviedo (Spain); Guerrero-Ruiz, Antonio [Department of Inorganic and technical Chemistry, UNED, 28040 Madrid (Spain); Castillejos-López, Eva; Rodríguez-Ramos, Inmaculada [Instituto de Catálisis y Petroleoquímica, CSIC, Madrid (Spain)

    2015-02-20

    Highlights: • Inverse gas chromatography and immersion calorimetry were compared on two MOFs. • Adsorption of seven carbon atoms adsorbates on Cu{sub 3}(BTC){sub 2} and Fe(BTC) was performed. • Size and polarizability of adsorbates are decisive in the strength of adsorption. • Dispersive interaction of surface free energy depends on the surface area. • I{sup sp} is influenced by the chemistry of adsorbates and morphology of the adsorbents. - Abstract: Two commercial metal-organic frameworks, Cu{sub 3}(BTC){sub 2} and Fe(BTC), have been selected to compare the adsorption parameters obtained on these materials by two different techniques: immersion calorimetry and inverse gas chromatography (IGC), in order to find a relationship between thermodynamic parameters obtained by so different techniques. From comparison between the enthalpy of adsorption obtained from IGC and the enthalpy of immersion, three molecules of the same number of carbon atoms have been selected: n-heptane, methylcyclohexane and toluene. Both by IGC and immersion calorimetry, the interaction is stronger in Fe(BTC), being the aromaticity of TOL determinant in the strength of the interaction. However, splitting of the enthalpy of adsorption into the dispersive and specific components allows to deduce that both parameters are more important on the Cu{sub 3}(BTC){sub 2}, due to the higher available surface area in the case of the dispersive interaction; and for the specific interaction, due to the high potential of interaction into the micropores.

  11. Effects of contact resistance and metal additives in finned-tube adsorbent beds on the performance of silica gel/water adsorption chiller

    OpenAIRE

    Rezk, Ahmed; Al-Dadah, R.K.; Mahmoud, S.; Elsayed, A.

    2013-01-01

    Recently interest in adsorption cooling systems has increased due to their capability to utilise low grade heat sources and environmentally friendly refrigerants. Currently, most of the commercially available adsorption cooling systems utilise granular packed adsorbent beds. Enhancing the heat transfer process inside the adsorbent bed will improve the overall efficiency of the adsorption system. Using recently developed empirical lumped analytical simulation model for a 450 kW two-bed silica ...

  12. Equilibrium and kinetic analysis of CO2-N2 adsorption separation by concentration pulse chromatography.

    Science.gov (United States)

    Li, Peiyuan; Tezel, F Handan

    2007-09-01

    CO2 and N(2) adsorption kinetics and equilibrium behaviours have been studied with silicalite, NaY and 13X by using concentration pulse chromatography for the separation of these gases in the present study. Adsorption Henry's Law constants, the heat of adsorption values, micropore diffusion coefficients and corresponding activation energies are determined experimentally and the three different mass transfer mechanisms are discussed. From the equilibrium data, the corresponding separation factors are obtained for the adsorption separation processes. The heat of adsorption values as well as the Henry's Law adsorption equilibrium constants of CO(2) are much higher than those of N(2) for all the adsorbents studied. 13X, NaY and silicalite all have good separation factors for CO(2)/N(2) system based on equilibrium processes. The order of the equilibrium separation factors is 13X (Ceca)>13X (Zeochem)>NaY (UOP)>silicalite (UOP). Equilibrium selectivity favours CO(2) over N(2). Micropore diffusion resistance is the definite dominant mass transfer mechanism for CO(2) with silicalite and NaY.

  13. Adsorption of carbon dioxide by sodium hydroxide-modified granular coconut shell activated carbon in a fixed bed

    International Nuclear Information System (INIS)

    In the present work, commercial coconut shell activated carbon was impregnated with alkaline NaOH to investigate the efficiency of modified activated carbon for CO2 adsorption in a fixed-bed column adsorption system. The modification parameters, such as the NaOH concentration (24–48%) and dwelling time (1–4 h), were also investigated. The results showed that a 32% NaOH concentration with a 3 h dwelling time provided the best CO2 adsorption capacity. Later, the modified activated carbon was characterized by nitrogen adsorption–desorption, scanning electron microscopy and Fourier transform infrared spectroscopy. The effects of the CO2 % in the feed, the adsorption temperature, the feed flow rate and the amount of adsorbent in the column were investigated in the adsorption experiments. The maximum CO2 adsorption capacity in this study was 27.10 mg/g at 35 °C. This study also suggests that NaOH-modified activated carbon is a state-of-the-art adsorbent for CO2 adsorption. - Highlights: • Coconut shell activated carbon was impregnated with alkaline NaOH. • CO2 was adsorbed in a fixed-bed column adsorption system. • The effects of CO2 concentration, temperature, flow rate and dose are analyzed. • Regeneration of modified activated carbons was effectively tested for ten cycles

  14. Batch and fixed-bed adsorption of tartrazine azo-dye onto activated carbon prepared from apricot stones

    Science.gov (United States)

    Albroomi, H. I.; Elsayed, M. A.; Baraka, A.; Abdelmaged, M. A.

    2016-02-01

    This work describes the potential of utilizing prepared activated carbon from apricot stones as an efficient adsorbent material for tartrazine (TZ) azo-dye removal in a batch and dynamic adsorption system. The results revealed that activated carbons with well-developed surface area (774 m2/g) and pore volume (1.26 cm3/g) can be manufactured from apricot stones by H3PO4 activation. In batch experiments, effects of the parameters such as initial dye concentration and temperature on the removal of the dye were studied. Equilibrium was achieved in 120 min. Adsorption capacity was found to be dependent on the initial concentration of dye solution, and maximum adsorption was found to be 76 mg/g at 100 mg/L of TZ. The adsorption capacity at equilibrium (q e) increased from 22.6 to 76 mg/g with an increase in the initial dye concentrations from 25 to 100 mg/L. The thermodynamic parameters such as change in free energy (ΔG 0), enthalpy (ΔH 0) and entropy (ΔS 0) were determined and the positive value of (ΔH) 78.1 (K J mol-1) revealed that adsorption efficiency increased with an increase in the process temperature. In fixed-bed column experiments, the effect of selected operating parameters such as bed depth, flow rate and initial dye concentration on the adsorption capacity was evaluated. Increase in bed height of adsorption columns leads to an extension of breakthrough point as well as the exhaustion time of adsorbent. However, the maximum adsorption capacities decrease with increases of flow rate. The breakthrough data fitted well to bed depth service time and Thomas models with high coefficient of determination, R 2 ≥ 94.

  15. Performance Study of a Four-Bed Silica Gel-Water Adsorption Chiller with the Passive Heat Recovery Scheme

    OpenAIRE

    Zhilong He; Xiaolin Wang; Hui Tong Chua

    2015-01-01

    Adsorption chiller technology is one of the effective means to convert waste thermal energy into effective cooling, which substantially improves energy efficiency and lowers environmental pollution. This paper uses an improved lump-parameter design model to theoretically and experimentally evaluate the efficacy of the passive heat recovery scheme as applied to a four-bed adsorption chiller. Results show that the model can accurately track the experimental temporal system outlet temperatures. ...

  16. Modeling of fixed-bed column studies for the adsorption of cadmium onto novel polymer-clay composite adsorbent

    International Nuclear Information System (INIS)

    Kaolinite clay was treated with polyvinyl alcohol to produce a novel water-stable composite called polymer-clay composite adsorbent. The modified adsorbent was found to have a maximum adsorption capacity of 20,400 ± 13 mg/L (1236 mg/g) and a maximum adsorption rate constant of ∼7.45 x 10-3 ± 0.0002 L/(min mg) at 50% breakthrough. Increase in bed height increased both the breakpoint and exhaustion point of the polymer-clay composite adsorbent. The time for the movement of the Mass Transfer Zone (δ) down the column was found to increase with increasing bed height. The presence of preadsorbed electrolyte and regeneration were found to reduce this time. Increased initial Cd2+ concentration, presence of preadsorbed electrolyte, and regeneration of polymer-clay composite adsorbent reduced the volume of effluent treated. Premodification of polymer-clay composite adsorbent with Ca- and Na-electrolytes reduced the rate of adsorption of Cd2+ onto polymer-clay composite and lowered the breakthrough time of the adsorbent. Regeneration and re-adsorption studies on the polymer-clay composite adsorbent presented a decrease in the bed volume treated at both the breakpoint and exhaustion points of the regenerated bed. Experimental data were observed to show stronger fits to the Bed Depth Service Time (BDST) model than the Thomas model.

  17. THE DETERMINATION OF ADSORPTION ISOTHERMS AND SOLID DIFFUSION COEFFICIENTS OF MANNITOL AND SORBITOL BY LIQUID CHROMATOGRAPHY TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    ZHAOYechun; XIHongxia; 等

    1999-01-01

    The parameter identification model is proposed for determining the linear adsorption isotherms and the solid diffusion coefficients by using adsorption chromatorgaphy.Axial dispersion coefficients is firstly determined by pulse-respond experiment technique with an inert substance as tracer,then the elution curves of chromatography separating the isomer mannitol and sorbitol are determined by the chromatographic measuring technique,and pinally the adsorption isotherms and the solid diffusion coefficients of mannitol and sorbitol on Ca2+ resins are estimated by using this model.The results show that the axial dispersion coefficients increase with fluid velocity increasing,The adsorption equilibrium constants decrease with temperature rising;and the solid diffusion coefficients increase with temperature rising.The theoretical elution curves are good agreement with the experimental elution curves of the liquid adsorption chromatography separating the mannitol and the sorbitol.The model provides a simple and reliable procedure to estimate the kinetic and thermodynamic parmeters of the adsorption.

  18. Adsorption and Step Elution of Urokinase Using, Affinity Chromatography -Comparison of Data with Rate Model Simulation

    Institute of Scientific and Technical Information of China (English)

    MohammadRezaAboudzadehRovais; JiawenZhu; BinWu

    2004-01-01

    A non-equilibrium chromatographic rate model was employed to simulate the affinity chromatography of urokinase. The chromatography process was developed to a yield of high purity product of urokinase from crude materials. The affinity gel used in the process was prepared by an epichlorohydrin-activation method using epichlorohydrin activated Sepharose 4B as a matrix and p-aminobenzamidine as a ligand. The chromatographic process were numerically simulated and analyzed with the aid of VERSE-LC computer simulator. Considering the basic principles, rate model with the back mixing in column inlet was utilized in simulating and studying the effect of the column inlet pattern on other parameters. Comparison of the simulation results with the experimental data showed that the rate model can be used to describe the affinity chromatography of urokinase in a fixed bed column with satisfactory accuracy.

  19. Evaluation of ammonium adsorption in biochar-fixed beds for treatment of anaerobically digested swine slurry: Experimental optimization and modeling.

    Science.gov (United States)

    Kizito, Simon; Wu, Shubiao; Wandera, Simon Mdondo; Guo, Luchen; Dong, Renjie

    2016-09-01

    Fixed-bed column experiments were performed to investigate the effect of influent concentration, flow rate, and adsorbent bed depth on ammonium adsorption from anaerobically digested swine slurry using three types of biochar made from corncobs (MCB), hardwood (WB), and mixed sawdust pellets (MSB). WB performed better than the other two biochar types with a maximum sorption capacity of 67-114mg/g due to its superior surface area and larger pore volume. Ammonium adsorption kinetics and dynamics depended on the influent NH4(+)-N concentration, applied inflow flow rate, and the depth of the fixed bed. Maximum sorption capacities under influent NH4(+)-N concentration of 500mg/L, were identified to be 114.2mg/g, 108.9mg/g, and 24.7mg/g at inflow rate of 15mL/min for WB, MCB, and MSB, respectively. The data shows that using deeper beds and applying lower flow rates could be a better strategy to increase ammonium adsorption in biochar-fixed beds. Moreover, three kinetic models (Thomas, Adams-Bohart (BDST), and Yoon-Nelson) were applied to the experimental data to predict breakthrough curves and determine characteristic adsorption parameters for process design. The applied models fitted data in the order: Thomas (R(2)=0.971)>BDST (R(2)=0.960)>Yoon-Nelson (R(2)=0.940). It was concluded that ammonium adsorption in biochar-fixed beds could be an effective method for routine cyclic treatment of slurry. However, further effluent polishing is required to meet discharge requirements.

  20. Evaluation of ammonium adsorption in biochar-fixed beds for treatment of anaerobically digested swine slurry: Experimental optimization and modeling.

    Science.gov (United States)

    Kizito, Simon; Wu, Shubiao; Wandera, Simon Mdondo; Guo, Luchen; Dong, Renjie

    2016-09-01

    Fixed-bed column experiments were performed to investigate the effect of influent concentration, flow rate, and adsorbent bed depth on ammonium adsorption from anaerobically digested swine slurry using three types of biochar made from corncobs (MCB), hardwood (WB), and mixed sawdust pellets (MSB). WB performed better than the other two biochar types with a maximum sorption capacity of 67-114mg/g due to its superior surface area and larger pore volume. Ammonium adsorption kinetics and dynamics depended on the influent NH4(+)-N concentration, applied inflow flow rate, and the depth of the fixed bed. Maximum sorption capacities under influent NH4(+)-N concentration of 500mg/L, were identified to be 114.2mg/g, 108.9mg/g, and 24.7mg/g at inflow rate of 15mL/min for WB, MCB, and MSB, respectively. The data shows that using deeper beds and applying lower flow rates could be a better strategy to increase ammonium adsorption in biochar-fixed beds. Moreover, three kinetic models (Thomas, Adams-Bohart (BDST), and Yoon-Nelson) were applied to the experimental data to predict breakthrough curves and determine characteristic adsorption parameters for process design. The applied models fitted data in the order: Thomas (R(2)=0.971)>BDST (R(2)=0.960)>Yoon-Nelson (R(2)=0.940). It was concluded that ammonium adsorption in biochar-fixed beds could be an effective method for routine cyclic treatment of slurry. However, further effluent polishing is required to meet discharge requirements. PMID:27241205

  1. Separation of galactoglucomannans, lignin, and lignin-carbohydrate complexes from hot-water-extracted Norway spruce by cross-flow filtration and adsorption chromatography

    Directory of Open Access Journals (Sweden)

    Niklas Westerberg

    2012-11-01

    Full Text Available A simple method to simultaneously recover polymeric carbohydrates, mainly galactoglucomannans (GGM, lignin, and lignin-carbohydrate complex (LCC from hot-water-extracted Norway spruce wood is presented. The isolation method consists of cross-flow filtration, where high and low molecular mass species are removed, followed by fixed-bed adsorption on a hydrophobic polymeric resin (XAD-16 to remove lignins and lignans. In the second step of fixed-bed adsorption, a phenylic reversed-phase analytical chromatography column, where mass transport resistance is minimized and a very high selectivity towards aromatic compounds have been observed, was used to separate LCC from GGM. The isolated LCC fraction contained about 10% aromatics, whereas the upgraded GGM fraction contained about 1.5% aromatics and the lignin fraction contained about 56% aromatics. Polymeric xylan was accumulated in the GGM fraction, while mannose was the dominant sugar found in the LCC fraction. As products, approximately 7% was recovered in the lignin fraction in the first adsorptive step, 5% was recovered as LCC, and 88% as upgraded hemicelluloses.

  2. A novel system for continuous protein refolding and on-line capture by expanded bed adsorption

    DEFF Research Database (Denmark)

    Ferré, Henrik; Ruffet, E; Nielsen, L.L.B;

    2005-01-01

    -h beta(2)m) both at analytical, small, and preparative scale. In a single scalable operation, extracted and denatured inclusion body proteins from Escherichia coli were continuously diluted into refolding buffer, using a short pipe reactor, allowing for a defined retention and refolding time......A novel two-step protein refolding strategy has been developed, where continuous renaturation-by-dilution is followed by direct capture on an expanded bed adsorption (EBA) column. The performance of the overall process was tested on a N-terminally tagged version of human beta(2)-microglobulin (HAT...... of the overall process was 45%, and the product loss was primarily a consequence of the refolding reaction rather than the EBA step. Full biological activity of HAT-h beta(2)m was demonstrated after removal of the HAT-tag. In contrast to batch refolding, a continuous refolding strategy allows the conditions...

  3. Aqueous phase adsorption of cephalexin by walnut shell-based activated carbon: A fixed-bed column study

    Science.gov (United States)

    Nazari, Ghadir; Abolghasemi, Hossein; Esmaieli, Mohamad; Sadeghi Pouya, Ehsan

    2016-07-01

    The walnut shell was used as a low cost adsorbent to produce activated carbon (AC) for the removal of cephalexin (CFX) from aqueous solution. A fixed-bed column adsorption was carried out using the walnut shell AC. The effect of various parameters like bed height (1.5, 2 and 2.5 cm), flow rate (4.5, 6 and 7.5 mL/min) and initial CFX concentration (50, 100 and 150 mg/L) on the breakthrough characteristics of the adsorption system was investigated at optimum pH 6.5. The highest bed capacity of 211.78 mg/g was obtained using 100 mg/L inlet drug concentration, 2 cm bed height and 4.5 mL/min flow rate. Three kinetic models, namely Adam's-Bohart, Thomas and Yoon-Nelson were applied for analysis of experimental data. The Thomas and Yoon-Nelson models were appropriate for walnut shell AC column design under various conditions. The experimental adsorption capacity values were fitted to the Bangham and intra-particle diffusion models in order to propose adsorption mechanisms. The effect of temperature on the degradation of CFX was also studied.

  4. Adsorption of phosphate from aqueous solutions and sewage using zirconium loaded okara (ZLO): Fixed-bed column study

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, T.A.H. [Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology, Sydney (UTS), 15 Broadway, Ultimo, NSW 2007 (Australia); Ngo, H.H., E-mail: ngohuuhao121@gmail.com [Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology, Sydney (UTS), 15 Broadway, Ultimo, NSW 2007 (Australia); Guo, W.S. [Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology, Sydney (UTS), 15 Broadway, Ultimo, NSW 2007 (Australia); Pham, T.Q. [Faculty of Geography, University of Science, Vietnam National University, Hanoi (Viet Nam); Li, F.M. [College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100 (China); Nguyen, T.V. [Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology, Sydney (UTS), 15 Broadway, Ultimo, NSW 2007 (Australia); Bui, X.T. [Environmental Engineering and Management Research Group, Ton Duc Thang University, Ho Chi Minh City (Viet Nam); Faculty of Environment and Natural Resources, Ho Chi Minh City University of Technology-Vietnam National University, Ho Chi Minh City (Viet Nam)

    2015-08-01

    This study explores the potential of removing phosphorus from aqueous solutions and sewage by Zr(IV)-loaded okara (ZLO) in the fixed-bed column. Soybean residue (okara) was impregnated with 0.25 M Zr(IV) solution to prepare active binding sites for phosphate. The effect of several factors, including flow rate, bed height, initial phosphorus concentration, pH and adsorbent particle size on the performance of ZLO was examined. The maximum dynamic adsorption capacity of ZLO for phosphorus was estimated to be 16.43 mg/g. Breakthrough curve modeling indicated that Adams–Bohart model and Thomas model fitted the experimental data better than Yoon–Nelson model. After treatment with ZLO packed bed column, the effluent could meet the discharge standard for phosphorus in Australia. Successful desorption and regeneration were achieved with 0.2 NaOH and 0.1 HCl, respectively. The results prove that ZLO can be used as a promising phosphorus adsorbent in the dynamic adsorption system. - Highlights: • Dynamic adsorption of P from water and wastewater by Zr(IV)-loaded okara was tested. • Effects of column design parameters on the adsorption performance were investigated. • The dynamic adsorption capacity of Zr(IV)-loaded okara for P was reasonably high. • The spent column was effectively regenerated with 0.2 M NaOH followed by 0.1 M HCl. • Zr(IV)-loaded okara column was efficient in eliminating P from municipal sewage.

  5. Performance Study of a Four-Bed Silica Gel-Water Adsorption Chiller with the Passive Heat Recovery Scheme

    Directory of Open Access Journals (Sweden)

    Zhilong He

    2015-01-01

    Full Text Available Adsorption chiller technology is one of the effective means to convert waste thermal energy into effective cooling, which substantially improves energy efficiency and lowers environmental pollution. This paper uses an improved lump-parameter design model to theoretically and experimentally evaluate the efficacy of the passive heat recovery scheme as applied to a four-bed adsorption chiller. Results show that the model can accurately track the experimental temporal system outlet temperatures. The performance predictions from this model compare favourably with experimental results. At rated temperature conditions and over a wide range of cycle times, both the cooling capacity and COP can be predicted to within 12.5%. The analyses indicate that the model can be used confidently as a design tool for a four-bed adsorption chiller and the passive heat recovery scheme can effectively improve the system performance.

  6. Development of a fluidized bed system for adsorption of phenol from aqueous solutions with commercial macroporous resins

    Directory of Open Access Journals (Sweden)

    R. A. Corrêa

    2007-03-01

    Full Text Available This work is related to removal of phenol from wastewaters by adsorption onto polymeric resins, a current alternative to activated carbon. A closed circuit, bench-scale liquid fluidized bed system was developed for this purpose. Phenol aqueous solutions with initial concentrations in the range of 0.084 to 0.451 kg/m³ were used to fluidize small permeable capsules of stainless steel screen containing a commercial resin at 308 K. Experiments were carried out using a fluidizing velocity 20% above that of the minimum fluidization of the capsules. Typically, 30 passages of the liquid volume circulating through the bed were required to reach a quasi-equilibrium concentration of phenol in the treated effluent. A simple batch adsorption model using the Freundlich isotherm successfully predicted final phenol concentrations. Suspended solids, often present in residual waters and a common cause of fixed bed clogging, were simulated with wood sawdust.

  7. Continuous adsorption of Pb(II) and methylene blue by engineered graphite oxide coated sand in fixed-bed column

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Ji-Lai, E-mail: jilaigong@gmail.com [College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082 (China); Zhang, Yong-Liang; Jiang, Yan [College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082 (China); Zeng, Guang-Ming, E-mail: zgming@hnu.edu.cn [College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082 (China); Cui, Zhi-Hui; Liu, Ke; Deng, Can-Hui; Niu, Qiu-Ya; Deng, Jiu-Hua [College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082 (China); Huan, Shuang-Yan [State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China)

    2015-03-01

    Highlights: • GO-sand was prepared by coating GO on the surface of sand. • Pb(II) and MB were efficiently removed by GO-sand filter in column. • The removal of MB was enhanced with the presence of Pb(II). • GO-sand is low-cost and convenient for its application as packed bed filter. - Abstract: The mixture of several effluents, caused by the improper handling and management of effluents, generated multi-component wastewater containing both metals and dyes, leading to the complicated treatment process. In this study, a continuous adsorption of Pb(II) and methylene blue (MB) has been studied in single and binary solutions by using graphite oxide coated sand (GO-sand) as an adsorbent in a fixed-bed column. GO-sand was analyzed by X-ray photoelectron spectroscopy before and after analyte adsorption. Compared with sand filter, adsorption quantity and capacity for Pb(II) and MB by GO-sand filter were greatly increased. In Pb(II) and MB single solutions, the experimental parameters were investigated in detail including initial concentration, flow rate, bed depth and pH. Exhaustion time decreased with increasing initial concentration and flow rate, and increased with increasing bed depth and pH. In the Pb(II)-MB binary solution, exhaustion time significantly decreased for Pb(II) adsorption, but increased for MB adsorption. The reason was explained that the more favorable adsorption for MB onto the surface of GO-sand than that for Pb(II), which was derived from π–π interaction between MB and GO on sand surface in packed filter. The Yoon–Nelson model was applied at different concentration of Pb(II) and MB to predict the breakthrough curves. The experimental data were well fit with the model indicating that it was suitable for this column design.

  8. Continuous adsorption of Pb(II) and methylene blue by engineered graphite oxide coated sand in fixed-bed column

    International Nuclear Information System (INIS)

    Highlights: • GO-sand was prepared by coating GO on the surface of sand. • Pb(II) and MB were efficiently removed by GO-sand filter in column. • The removal of MB was enhanced with the presence of Pb(II). • GO-sand is low-cost and convenient for its application as packed bed filter. - Abstract: The mixture of several effluents, caused by the improper handling and management of effluents, generated multi-component wastewater containing both metals and dyes, leading to the complicated treatment process. In this study, a continuous adsorption of Pb(II) and methylene blue (MB) has been studied in single and binary solutions by using graphite oxide coated sand (GO-sand) as an adsorbent in a fixed-bed column. GO-sand was analyzed by X-ray photoelectron spectroscopy before and after analyte adsorption. Compared with sand filter, adsorption quantity and capacity for Pb(II) and MB by GO-sand filter were greatly increased. In Pb(II) and MB single solutions, the experimental parameters were investigated in detail including initial concentration, flow rate, bed depth and pH. Exhaustion time decreased with increasing initial concentration and flow rate, and increased with increasing bed depth and pH. In the Pb(II)-MB binary solution, exhaustion time significantly decreased for Pb(II) adsorption, but increased for MB adsorption. The reason was explained that the more favorable adsorption for MB onto the surface of GO-sand than that for Pb(II), which was derived from π–π interaction between MB and GO on sand surface in packed filter. The Yoon–Nelson model was applied at different concentration of Pb(II) and MB to predict the breakthrough curves. The experimental data were well fit with the model indicating that it was suitable for this column design

  9. Adsorption of hexavalent chromium from synthetic and electroplating effluent on chemically modified Swietenia mahagoni shell in a packed bed column.

    Science.gov (United States)

    Rangabhashiyam, S; Nandagopal, M S Giri; Nakkeeran, E; Selvaraju, N

    2016-07-01

    Packed bed column studies were carried out to evaluate the performance of chemically modified adsorbents for the sequestration of hexavalent chromium from synthetic and electroplating industrial effluent. The effects of parameters such as bed height (3-9 cm), inlet flow rate (5-15 mL/min), and influent Cr(VI) concentration (50-200 mg/L) on the percentage removal of Cr(VI) and the adsorption capacity of the adsorbents in a packed bed column were investigated. The breakthrough time increased with increasing bed height and decreased with the increase of inlet flow rate and influent Cr(VI) concentration. The adsorption column models such as Thomas, Adams-Bohart, Yoon-Nelson, and bed depth service time (BDST) were successfully correlated with the experimental data. The Yoon-Nelson and BDST model showed good agreement with the experimental data for all the studied parameter conditions. Results of the present study indicated that the chemically modified Swietenia mahagoni shell can be used as an adsorbent for the removal of Cr(VI) from industrial wastewater in a packed bed column. PMID:27312254

  10. Adsorption and desorption of noble gases on activated charcoal: II. 222Rn studies in a monolayer and packed bed.

    Science.gov (United States)

    Scarpitta, S C; Harley, N H

    1990-10-01

    The adsorptive and desorptive characteristics of canisters containing a petroleum-based charcoal were investigated under controlled conditions of temperature, relative humidity, and Rn concentration. Charcoals exposed in a monolayer and packed bed during exposure intervals of 1-7 d demonstrate that Rn adsorption and desorption are dependent on bed depth and the amount of water adsorbed. Changes in the adsorptive and desorptive properties of the charcoal occurred near the break-point where the pores became occluded by water vapor that condenses in the entrance capillaries. Radon-222 adsorption is decreased by an order of magnitude as the amount of adsorbed water exceeds the break-point of the charcoal. The reduction in pore surface due to adsorbed water results in a marked increase in the rate of Rn loss from exposed canisters, accounting for reduced adsorption. The apparent desorption time-constant for a 2-cm bed of loose Witco 6 x 10 mesh charcoal containing 0.220-0.365 kg H2O kg-1 is typically between 2-8 h. The apparent desorption time-constant for an equivalent packed bed containing a water vapor content of 0.026-0.060 kg H2O kg-1, which is below the break-point of the charcoal, is about 15-30 h. Conventional charcoal canisters, if exposed in the fully-opened configuration, can achieve the break-point in less than 4 d at 70% humidity. The use of a diffusion barrier would allow for longer exposure times until the break-point of the charcoal is achieved. PMID:2398008

  11. A regularization method for the reconstruction of adsorption isotherms in liquid chromatography

    Science.gov (United States)

    Zhang, Ye; Lin, Guang-Liang; Forssén, Patrik; Gulliksson, Mårten; Fornstedt, Torgny; Cheng, Xiao-Liang

    2016-10-01

    Determining competitive adsorption isotherms is an open problem in liquid chromatography. Since traditional experimental trial-and-error approaches are too complex and expensive, a modern technique of obtaining adsorption isotherms is to solve the inverse problem so that the simulated batch separation coincides with actual experimental results. This is a typical ill-posed problem. Moreover, in almost all cases the observed concentration at the outlet is the total response of all components, which makes the problem more difficult. In this work, we tackle the ill-posedness with a new regularization method, which is based on the fact that the adsorption isotherms do not depend on the injection profile. The proposed method transfers the original problem to an optimization problem with a time-dependent convection-diffusion equation constraint. Iterative algorithms for solving constraint optimization problems for both the equilibrium-dispersive and the transport-dispersive models are developed. The mass transfer resistance is also estimated by the proposed inverse method. A regularization parameter selection method and the convergence property of the proposed algorithm are discussed. Finally, numerical tests for both synthetic problems and real-world problems are given to show the efficiency and feasibility of the proposed regularization method.

  12. Exogenous factors contributing to column bed heterogeneity: Part 1: Consequences of 'air' injections in liquid chromatography.

    Science.gov (United States)

    Samuelsson, Jörgen; Fornstedt, Torgny; Shalliker, Andrew

    2015-08-01

    It has been shown that not only the packing homogeneity, but also factors external to the column bed, such as, frits and distributors can have important effects on the column performance. This current communication is the first in a series focusing on the impact of exogenous factors on the column bed heterogeneity. This study is based on several observations by us and others that chromatographic runs often, for technical reasons, include more or less portions of air in the injections. It is therefore extremely important to find out the impact of air on the column performance, the reliability of the results derived from analyses where air was injected, and the effect on the column homogeneity. We used a photographic approach for visualising the air transport phenomena, and found that the air transport through the column is comprised of many different types of transport phenomena, such as laminal flow, viscous fingering like flows, channels and bulbs, and pulsations. More particularly, the air clouds within the column definitely interact in the adsorption, i.e. mobile phase adsorbed to the column surface is displaced. In addition, irrespective of the type of air transport phenomena, the air does not penetrate the column homogeneously. This process is strongly flow dependent. In this work we study air transport both in an analytical scale and a semi-prep column.

  13. Expanded bed chromatography of proteins in small-diameter columns. II. Methods development and scale up.

    Science.gov (United States)

    Ghose, S; Chase, H

    2000-01-01

    The scaled down system developed in Part I of this series was further validated by using a 1-cm diameter column for method development studies for the separation of two model proteins, alcohol dehydrogenase and alpha-glucosidase, from unclarified yeast homogenate by hydrophobic interaction expanded bed chromatography based on the STREAMLINE matrix. The efficacy of solids removal and establishment of optimal binding and separation condition by stepwise elution were investigated. Equilibration of the EBA column and loading at high salt strengths affected the subsequent recovery of the two target proteins. Although good resolution between the target proteins could be achieved, peak tailing was found to be a consistent problem. The optimised separation protocol was scaled up 25-fold to a column diameter of 5.0 cm. The results were in good agreement with the run conducted in the 1-cm column, indicating the potential of using the small columns as an viable approach for method scouting and development studies.

  14. AN EXTRACORPOREAL STABILISED EXPANDED BED ADSORPTION METHOD FOR THE TREATMENT OF SEPSIS

    DEFF Research Database (Denmark)

    2004-01-01

    The present invention provides an extracorporeal adsorption method for removing harmful substances from blood in a way that is practicable in everyday clinical practice and applicable for the timely intervention to present the development of sepsis. Said extracorporeal adsorption method being...... effected by an adsorption column assembly where the adsorption column assembly comprising a column and an adsorption medium in the form of particles. The sedimented volume of said particles being at the most 80% of the volume of the column....

  15. Efficacy of Zeolite Adsorption on the Green Tea Production by Fluidized Bed Dryer

    Directory of Open Access Journals (Sweden)

    Sri Utami Handayani

    2015-04-01

    Full Text Available Green tea (classified as unfermented tea gained more attention due to their health benefit. Since green tea included to the heat sensitive product, it required the application of low drying temperature during moisture content removal. In order to avoid the unwanted of metabolic process due to longer drying period, the application of zeolite adsorption for air dehumidication in the fluidized bed drier was investigated. This study focuses on the effect of air flow rate, temperature and zeolite-tea leave ratio on the moisture content and drying time. The longer the drying time, the moisture content of green tea leaves decreases significantly. The fastest decreasing time obtained when applying 0,46 m/sec of air flow rate with 70C of drying temperature and 25:75 of zeolite-tea leave ratio. Decreasing the drying temperature at 50C, longer the drying time than drying at 70C while slower air flow rate (0, 44 m/sec applied. Modifying the zeolite-tea leave ratio from 25:75 into 75:25, fasten the drying time.

  16. Multi-Bed Multi-Stage Adsorption Refrigeration Cycle-Reducing Driving Heat Source Temperature

    Science.gov (United States)

    Alam, K. C. Amanul; Akahira, Akira; Hamamoto, Yoshinori; Akisawa, Atsushi; Kashiwagi, Takao; Saha, Bidyut Baran; Koyama, Shigeru; Ng, Kim Choon; Chua, Hui Tong

    The study aims at designing a multi-bed multi-stage adsorption chiller that can be driven by waste heat at near ambient temperature. The chiller is designed such a way that it can be switched into different modes depending on the driving heat source temperature. Stage regeneration techniques have been applied to operate the chiller by relatively low temperature heat source. Driving heat source temperature is validated by simulated data and the performances obtained from different modes are compared. In terms of COP (Coefficient of performance),the chiller shows best performance in conventional single-stage mode for driving heat source temperature greater than 60°C, two stage mode for driving source temperature between 42 and 60°C,in three-stage mode for driving source temperature less than 42°C. In terms of cooling capacity, it shows the best performance in single-stage mode for heat source temperature greater than 70°C. The mass recovery process in single-stage mode is also examined. It is seen that the mass recovery process improve cooling capacity significantly, specially for the low regenerating temperature region.

  17. Chiral separation of non-steroidal anti-inflammatory drugs by preparative and simulated moving bed chromatography

    OpenAIRE

    Ribeiro, António E.; Gomes, Pedro Sá; Pais, L.S.; A.E. Rodrigues

    2011-01-01

    The work presents modelling, simulation and experimental results for the chiral separation of non-steroidal anti-inflammatory drugs, particularly, the optimization of mobile phase composition under preparative and simulated moving bed chromatography. The experimental separation of two chiral systems (ketoprofen and flurbiprofen enantiomers) will be presented to show how compounds of the same family can lead to different solutions.

  18. Preparative chromatography with supercritical fluids. Comparison of simulated moving bed and batch processes.

    Science.gov (United States)

    Peper, Stephanie; Johannsen, Monika; Brunner, Gerd

    2007-12-28

    Preparative chromatography is a key technology for the separation of fine chemicals in production scale. Most of the published studies are carried out using liquid solvents as mobile phase. However, the used organic solvents can often be replaced by supercritical fluids. A reduction or renouncement of organic solvents does not only correspond to the trend of the so-called green chemistry--a sustainable, environmentally friendly production of chemical products. But a changeover to chromatography with supercritical fluids can also be reasonable under economic criteria. In this contribution a comparison between the Batch-supercritical fluid chromatography (Batch-SFC) process and the simulated moving bed (SMB)-SFC process is presented. Because of the minor importance of solvent consumption and solvent recovery in SFC, the separation systems were optimized primarily in terms of their specific productivity. For three of the four investigated model systems, the specific productivity of the SMB process is significantly higher than the productivity of the Batch process. Due to the fact, that the process with the higher specific productivity is not inevitably the more economical process, supplementary the costs of the process were considered. Therefore the comparison of the two processes was done from an economic point of view considering the minimum product price that has to be realized to fulfill the defined economic aim. It was found that although the optimized specific productivities of the SMB process were significantly higher than the productivities of the Batch process, the Batch process is the more profitable process for the investigated production rate range between 0.4 and 5t/a.

  19. Fixed-bed adsorption separation of xylene isomers over sio2/silicallite-1 core-shell adsorbents

    KAUST Repository

    Khan, Easir A.

    2013-12-29

    SiO2/Silicalite-1 core-shell material has been demonstrated as potential shape selective adsorbent in gas phase separation of p-xylene from a mixture of p/o-xylene isomers. The core-shell composite comprised of large silica core and thin polycrystalline silicalite-1 shell which was synthesized via a self-assembly of silicalite-1 nanocrystals on core silica surface followed by a secondary seeded growth method. The core materials, SiO2 used in this study has mesoporosity with an average pore diameter of 60Å and hence offers no shape selectivity for xylene isomers. However, the shell, silicalite-1 contains rigid pore structures and preferentially adsorbs p-xylene from their isomers mixtures. A series of adsorption fixed bed breakthrough adsorption/desorption experiment was performed to obtain the equilibrium isotherms and adsorption isotherm parameters of xylene isomers. The equilibrium isotherms of xylene isomers follow the Langmuir\\'s model. A chromatographic adsorption model has been used to describe the fixed-bed breakthrough profiles of xylene isomers. The model has successfully predicted the responses of the binary mixtures of p/o-xylene isomers. The SiO2/silicalite-1 core-shell adsorbents have shown para-selectivity as high as 15. © Bangladesh Uni. of Engg. & Tech.

  20. VOC emission control by circulating fluidized bed adsorption; Controle de l'emission de composes organiques volatils par adsorption en lit fluidise circulant

    Energy Technology Data Exchange (ETDEWEB)

    Song, W.

    2003-12-15

    This work deals with the circulating fluidized bed technology, applied to the elimination by adsorption of volatile organic compounds (VOCs), like toluene, in a gas flow. In the process, the adsorbent (millimetric spherical grains of micro-porous carbon) is moved by a strong flow rate of gas inside a vertical tube without lining. Mass and heat transfers are very important and important volumes of compounds can be processed. This work presents the determination of the adsorption equilibrium, the description of the experimental facility and of the results of experiments, the development of an original model of the process which combines a flow model and a mass transfer model, a parametric study of this model, and finally, some extensions of the process principle to staged operations with pressure variation or temperature variation cycles. (J.S.)

  1. A closer study of methanol adsorption and its impact on solute retentions in supercritical fluid chromatography.

    Science.gov (United States)

    Glenne, Emelie; Öhlén, Kristina; Leek, Hanna; Klarqvist, Magnus; Samuelsson, Jörgen; Fornstedt, Torgny

    2016-04-15

    Surface excess adsorption isotherms of methanol on a diol silica adsorbent were measured in supercritical fluid chromatography (SFC) using a mixture of methanol and carbon dioxide as mobile phase. The tracer pulse method was used with deuterium labeled methanol as solute and the tracer peaks were detected using APCI-MS over the whole composition range from neat carbon dioxide to neat methanol. The results indicate that a monolayer (4Å) of methanol is formed on the stationary phase. Moreover, the importance of using the set or the actual methanol fractions and volumetric flows in SFC was investigated by measuring the mass flow respective pressure and by calculations of the actual volume fraction of methanol. The result revealed a significant difference between the value set and the actually delivered volumetric methanol flow rate, especially at low modifier fractions. If relying only on the set methanol fraction in the calculations, the methanol layer thickness should in this system be highly overestimated. Finally, retention times for a set of solutes were measured and related to the findings summarized above concerning methanol adsorption. A strongly non-linear relationship between the logarithms of the retention factors and the modifier fraction in the mobile phase was revealed, prior to the established monolayer. At modifier fractions above that required for establishment of the methanol monolayer, this relationship turns linear which explains why the solute retention factors are less sensitive to changes in modifier content in this region.

  2. A closer study of methanol adsorption and its impact on solute retentions in supercritical fluid chromatography.

    Science.gov (United States)

    Glenne, Emelie; Öhlén, Kristina; Leek, Hanna; Klarqvist, Magnus; Samuelsson, Jörgen; Fornstedt, Torgny

    2016-04-15

    Surface excess adsorption isotherms of methanol on a diol silica adsorbent were measured in supercritical fluid chromatography (SFC) using a mixture of methanol and carbon dioxide as mobile phase. The tracer pulse method was used with deuterium labeled methanol as solute and the tracer peaks were detected using APCI-MS over the whole composition range from neat carbon dioxide to neat methanol. The results indicate that a monolayer (4Å) of methanol is formed on the stationary phase. Moreover, the importance of using the set or the actual methanol fractions and volumetric flows in SFC was investigated by measuring the mass flow respective pressure and by calculations of the actual volume fraction of methanol. The result revealed a significant difference between the value set and the actually delivered volumetric methanol flow rate, especially at low modifier fractions. If relying only on the set methanol fraction in the calculations, the methanol layer thickness should in this system be highly overestimated. Finally, retention times for a set of solutes were measured and related to the findings summarized above concerning methanol adsorption. A strongly non-linear relationship between the logarithms of the retention factors and the modifier fraction in the mobile phase was revealed, prior to the established monolayer. At modifier fractions above that required for establishment of the methanol monolayer, this relationship turns linear which explains why the solute retention factors are less sensitive to changes in modifier content in this region. PMID:26979267

  3. Application of shrinking core model to the adsorption of oxytetracycline onto peanut hull-derived activated carbon in a closed-loop fixed-bed reactor

    OpenAIRE

    Djedouani, D.; Chabani, M.; Amrane, Abdeltif; Bensmaili, A

    2016-01-01

    International audience In the present paper, the ability of peanut hull-derived activated carbon AC(PH-800) to adsorb oxytetracycline (OTC) was investigated using batch adsorption with fixed-bed reactor. The factors influencing adsorption, such as contact time and sorbent concentration, were evaluated. Sorption kinetic and equilibrium data of OTC sorption onto AC(PH-800) were submitted to kinetics and equilibrium models in order to calculate the adsorption constant rate and the maximum cap...

  4. Efficiency Assessment of Fixed Bed Adsorption Column for the Removal of nitrate using PAN-oxime-nano Fe2O3

    Directory of Open Access Journals (Sweden)

    M Jahangiri-rad

    2015-08-01

    Conclusion: fixed-bed using PAN-oxime-nano Fe2O3 exhibited good removal of nitrate. The adsorption studies showed that at longer bed depth, better removal of nitrate would be achieved. Thomas model was suitable for the normal description of breakthrough curve at the experimental condition. The data also were in good agreement with logistic regression.

  5. Adsorptive removal of heavy metals from water using sodium titanate nanofibres loaded onto GAC in fixed-bed columns.

    Science.gov (United States)

    Sounthararajah, D P; Loganathan, P; Kandasamy, J; Vigneswaran, S

    2015-04-28

    Heavy metals are serious pollutants in aquatic environments. A study was undertaken to remove Cu, Cd, Ni, Pb and Zn individually (single metal system) and together (mixed metals system) from water by adsorption onto a sodium titanate nanofibrous material. Langmuir adsorption capacities (mg/g) at 10(-3)M NaNO3 ionic strength in the single metal system were 60, 83, 115 and 149 for Ni, Zn, Cu, and Cd, respectively, at pH 6.5 and 250 for Pb at pH 4.0. In the mixed metals system they decreased at high metals concentrations. In column experiments with 4% titanate material and 96% granular activated carbon (w/w) mixture at pH 5.0, the metals breakthrough times and adsorption capacities (for both single and mixed metals systems) decreased in the order Pb>Cd, Cu>Zn>Ni within 266 bed volumes. The amounts adsorbed were up to 82 times higher depending on the metal in the granular activated carbon+titanate column than in the granular activated carbon column. The study showed that the titanate material has high potential for removing heavy metals from polluted water when used with granular activated carbon at a very low proportion in fixed-bed columns.

  6. Continuous adsorption and biotransformation of micropollutants by granular activated carbon-bound laccase in a packed-bed enzyme reactor.

    Science.gov (United States)

    Nguyen, Luong N; Hai, Faisal I; Dosseto, Anthony; Richardson, Christopher; Price, William E; Nghiem, Long D

    2016-06-01

    Laccase was immobilized on granular activated carbon (GAC) and the resulting GAC-bound laccase was used to degrade four micropollutants in a packed-bed column. Compared to the free enzyme, the immobilized laccase showed high residual activities over a broad range of pH and temperature. The GAC-bound laccase efficiently removed four micropollutants, namely, sulfamethoxazole, carbamazepine, diclofenac and bisphenol A, commonly detected in raw wastewater and wastewater-impacted water sources. Mass balance analysis showed that these micropollutants were enzymatically degraded following adsorption onto GAC. Higher degradation efficiency of micropollutants by the immobilized compared to free laccase was possibly due to better electron transfer between laccase and substrate molecules once they have adsorbed onto the GAC surface. Results here highlight the complementary effects of adsorption and enzymatic degradation on micropollutant removal by GAC-bound laccase. Indeed laccase-immobilized GAC outperformed regular GAC during continuous operation of packed-bed columns over two months (a throughput of 12,000 bed volumes). PMID:26803903

  7. Adsorption of phosphate from aqueous solutions and sewage using zirconium loaded okara (ZLO): Fixed-bed column study.

    Science.gov (United States)

    Nguyen, T A H; Ngo, H H; Guo, W S; Pham, T Q; Li, F M; Nguyen, T V; Bui, X T

    2015-08-01

    This study explores the potential of removing phosphorus from aqueous solutions and sewage by Zr(IV)-loaded okara (ZLO) in the fixed-bed column. Soybean residue (okara) was impregnated with 0.25M Zr(IV) solution to prepare active binding sites for phosphate. The effect of several factors, including flow rate, bed height, initial phosphorus concentration, pH and adsorbent particle size on the performance of ZLO was examined. The maximum dynamic adsorption capacity of ZLO for phosphorus was estimated to be 16.43mg/g. Breakthrough curve modeling indicated that Adams-Bohart model and Thomas model fitted the experimental data better than Yoon-Nelson model. After treatment with ZLO packed bed column, the effluent could meet the discharge standard for phosphorus in Australia. Successful desorption and regeneration were achieved with 0.2 NaOH and 0.1 HCl, respectively. The results prove that ZLO can be used as a promising phosphorus adsorbent in the dynamic adsorption system. PMID:25847314

  8. Recovery and purification of chitosanase produced by Bacillus cereus using expanded bed adsorption and central composite design.

    Science.gov (United States)

    de Araújo, Nathália Kelly; Pimentel, Vanessa Carvalho; da Silva, Nayane Macedo Portela; de Araújo Padilha, Carlos Eduardo; de Macedo, Gorete Ribeiro; Dos Santos, Everaldo Silvino

    2016-02-01

    This study presents a system for expanded bed adsorption for the purification of chitosanase from broth extract in a single step. A chitosanase-producing strain was isolated and identified as Bacillus cereus C-01 and used to produce chitosanases. The expanded bed adsorption conditions for chitosanase purification were optimized statistically using STREAMLINE(TM) DEAE and a homemade column (2.6 × 30.0 cm). Dependent variables were defined by the quality criteria purification factor (P) and enzyme yield to optimize the chromatographic process. Statistical analyses showed that the optimum conditions for the maximum P were 150 cm/h load flow velocity, 6.0 cm settled bed height, and 7.36 cm distributor height. Distributor height had a strong influence on the process, considerably affecting both the P and enzyme yield. Optimizing the purification variables resulted in an approximately 3.66-fold increase in the P compared with the value under nonoptimized conditions. This system is promising for the recovery of chitosanase from B. cereus C-01 and is economically viable because it promotes the reduction steps. PMID:26638991

  9. Competitive Fixed-Bed Adsorption of Pb(II, Cu(II, and Ni(II from Aqueous Solution Using Chitosan-Coated Bentonite

    Directory of Open Access Journals (Sweden)

    Wan-Chi Tsai

    2016-01-01

    Full Text Available Fixed-bed adsorption studies using chitosan-coated bentonite (CCB as adsorbent media were investigated for the simultaneous adsorption of Pb(II, Cu(II, and Ni(II from a multimetal system. The effects of operational parameters such as bed height, flow rate, and initial concentration on the length of mass transfer zone, breakthrough time, exhaustion time, and adsorption capacity at breakthrough were evaluated. With increasing bed height and decreasing flow rate and initial concentration, the breakthrough and exhaustion time were observed to favorably increase. Moreover, the adsorption capacity at breakthrough was observed to increase with decreasing initial concentration and flow rate and increasing bed height. The maximum adsorption capacity at breakthrough of 13.49 mg/g for Pb(II, 12.14 mg/g for Cu(II, and 10.29 mg/g for Ni(II was attained at an initial influent concentration of 200 mg/L, bed height of 2.0 cm, and flow rate of 0.4 mL/min. Adsorption data were fitted with Adams-Bohart, Thomas, and Yoon-Nelson models. Experimental breakthrough curves were observed to be in good agreement (R2>0.85 and E%<50% with the predicted curves generated by the kinetic models. This study demonstrates the effectiveness of CCB in the removal of Pb(II, Cu(II, and Ni(II from a ternary metal solution.

  10. Adsorption-induced deformation in porous media and application to CO2-injected coal beds

    OpenAIRE

    Vandamme, Matthieu; Brochard, Laurent,; Coussy, Olivier

    2010-01-01

    An injection of carbon dioxide into a coal bed methane reservoir facilitates the recovery of methane, a process known as enhanced coal bed methane recovery (ECBM). The injected carbon dioxide can then remain stored for geological periods of time. Over the process carbon dioxide gets adsorbed at the surface of the coal pores, which causes the coal to swell. In confined conditions this swelling leads to a closure of the coal reservoir cleat (fracture) system. Since permeability in coal beds is ...

  11. Simulation assessment of continuous simulating moving bed chromatography process with partial feed and new strategy with partial feed

    OpenAIRE

    Khan, H.

    2009-01-01

    Partial Feed simulating moving bed (SMB) has proved to be more efficient in binary separation performance (purity, recovery, productivity) because of its two additional degrees of freedom, namely feed length and feed time, as compared to classical SMB process. The binary separation of dextran T6 and fructose with linear isotherm is modeled with Aspen Chromatography simulator in a four zone SMB with one column per zone for both normal-feed and Partial Feed. Increase in number of feed length an...

  12. Adsorptive Removal of Trichloroethylene in Water by Crop Residue Biochars Pyrolyzed at Contrasting Temperatures: Continuous Fixed-Bed Experiments

    OpenAIRE

    Ming Zhang; Mahtab Ahmad; Al-Wabel, Mohammad I.; Meththika Vithanage; Anushka Upamali Rajapaksha; Hyuck Soo Kim; Sang Soo Lee; Yong Sik Ok

    2015-01-01

    Biochar (BC) has attracted great attention as an alternative sorbent to activated carbon (AC). Objective of this study was to determine trichloroethylene (TCE) removal by soybean stover BC pyrolyzed at 300 (BC300) and 700°C (BC700) in continuous fixed-bed column. Columns packed with BC300, BC700, and AC reached breakthrough time in 1.1, 27.0, and 50.7 h, respectively. BC700 had higher TCE adsorption capacity than BC300 due to its higher surface area, nonpolarity, and aromaticity. The sorption...

  13. Chromatography.

    Science.gov (United States)

    Brantley, L. Reed, Sr.; Demanche, Edna L.; Klemm, E. Barbara; Kyselka, Will; Phillips, Edwin A.; Pottenger, Francis M.; Yamamoto, Karen N.; Young, Donald B.

    This booklet presents some activities on chromatography. Directions for preparing leaf pigment extracts using alcohol are given, and paper chromatography and thin-layer chromatography are described as modifications of the basic principles of chromatography. (KHR)

  14. A New Rapid Determination Method of Soil Organic Carbon Adsorption Coefficients of Pesticides with Soil Column Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Soil column liquid chromatography (SCLC) was developed to determine soil organic carbon adsorption coefficients (Koc) for chemicals. The uptake by soil of pesticides from water can be conveniently calculated from the related breakthrough curves (BTC). The nine pesticides chosen for determination in this study are soluble ones, with their water solubility ranging from 62 mg/L to 2 mg/L. In comparing with existing methods of Koc, SCLC possesses rapid, online and accurate characteristics.

  15. Isolation of bovine serum albumin from whey using affinity chromatography

    NARCIS (Netherlands)

    Besselink, T.; Janssen, A.E.M.; Boom, R.M.

    2015-01-01

    The adsorption of bovine serum albumin (BSA) to a chromatography resin with immobilised llama antibody fragments as affinity ligands was investigated. The maximum adsorption capacity of the affinity resin was 21.6 mg mL-1 with a Langmuir equilibrium constant of 20.4 mg mg-1. Using packed bed chromat

  16. CFD Simulation and Experimental Analyses of a Copper Wire Woven Heat Exchanger Design to Improve Heat Transfer and Reduce the Size of Adsorption Beds

    Directory of Open Access Journals (Sweden)

    John White

    2016-02-01

    Full Text Available The chief objective of this study is the proposal design and CFD simulation of a new compacted copper wire woven fin heat exchanger and silica gel adsorbent bed used as part of an adsorption refrigeration system. This type of heat exchanger design has a large surface area because of the wire woven fin design. It is estimated that this will help improve the coefficient of performance (COP of the adsorption phase and increase the heat transfer in this system arrangement. To study the heat transfer between the fins and porous adsorbent reactor bed, two experiments were carried out and matched to computational fluid dynamics (CFD results.

  17. Optimization of simulated moving bed (SMB) chromatography: a multi-level optimization procedure

    DEFF Research Database (Denmark)

    Jørgensen, Sten Bay; Lim, Young-il

    2004-01-01

    objective functions (productivity and desorbent consumption), employing the standing wave analysis, the true moving bed (TMB) model and the simulated moving bed (SMB) model. The procedure is constructed on a non-worse solution property advancing level by level and its solution does not mean a global optimum...

  18. Experimental and Numerical Investigation of Adsorption/Desorption in Packed Sorption Beds Under Ideal and Non-Ideal Flows

    Science.gov (United States)

    Mohamadinejad, H.; Knox, J. C.; Smith, James E.

    1999-01-01

    The importance of the wall effect on packed beds in the adsorption and desorption of carbon dioxide, nitrogen, and water on molecular sieve 5A of 0.127 cm in radius is examined experimentally and with one-dimensional computer simulations. Experimental results are presented for a 22.5-cm long by 4.5-cm diameter cylindrical column with concentration measurements taken at various radial locations. The set of partial differential equations are solved using finite differences and Newman's method. Comparison of test data with the axial-dispersed, non-isothermal, linear driving force model suggests that a two-dimensional model (submitted to Separation Science and Technology) is required for accurate simulation of the average column breakthrough concentration. Additional comparisons of test data with the model provided information on the interactive effects of carrier gas coadsorption with CO2, as well as CO2-H2O interactions.

  19. An entropy generation and genetic algorithm optimization of two-bed adsorption cooling cycle

    KAUST Repository

    Myat, Aung

    2011-09-28

    This article presents the performance analysis of adsorption cooling, shortly AD, system using a thermodynamic framework with an entropy generation analysis. The model captures the transient and the cyclic steady-state performances of the adsorption-desorption cycles operating under assorted heat source temperatures. Type-RD silica gel, with a pore surface area of 720 m2/g and diameters 0.4-0.7 mm, is used as an adsorbent and its high affinity for thewater vapour adsorbate gives a high equilibrium uptake. The key advantages of the AD are (a) it has no moving parts rendering less maintenance and (b) the energy efficient means of cooling by the adsorption process with a low-temperature heat source and (c) it is environmental friendly with low carbon footprint. By incorporating the genetic algorithm onto the entropy minimization technique, it is possible to locate the optimal system performance point or the global minima with respect to entropy generation using the system parameters such as coolant and heat source water temperatures, heat transfer areas, etc. The system analysis shows that the minimization of entropy generation in the AD cycle leads to the maximization of the coefficient of performance and this translates into a higher delivery of useful cooling effects at the particular input resource temperature. © Authors 2011.

  20. Adsorption and desorption kinetics of bovine serum albumin in ion exchange and hydrophobic interaction chromatography on silica matrices.

    Science.gov (United States)

    Conder; Hayek

    2000-12-01

    Large scale chromatographic separation of proteins can be carried out more rapidly on rigid adsorbents than on soft gel media. The kinetics of adsorption of bovine serum albumin (BSA) have been studied on rigid adsorbents based on a wide-pore, hydrophilically-coated silica gel matrix in a packed bed (chromatographic column). Process parameters have been varied comprehensively. The effects of surface chemistry (weak anion exchanger and hydrophobic interaction), particle size and liquid flow velocity have been studied on both the adsorption and desorption processes. The relative influences of the adsorption kinetics and equilibrium isotherm on the shape of the breakthrough curve are found to vary with the process parameters in an interpretable and therefore, predictable manner. Pore diffusion resistance is dominant over the external liquid film resistance in controlling the adsorption kinetics, with Biot numbers in the range 170-2600. A two-step model based on these two resistances simulates the breakthrough curves with only limited quantitative accuracy, but gives good predictions of the effect of changes in process parameters. PMID:11080653

  1. Adsorptive Removal of Trichloroethylene in Water by Crop Residue Biochars Pyrolyzed at Contrasting Temperatures: Continuous Fixed-Bed Experiments

    Directory of Open Access Journals (Sweden)

    Ming Zhang

    2015-01-01

    Full Text Available Biochar (BC has attracted great attention as an alternative sorbent to activated carbon (AC. Objective of this study was to determine trichloroethylene (TCE removal by soybean stover BC pyrolyzed at 300 (BC300 and 700°C (BC700 in continuous fixed-bed column. Columns packed with BC300, BC700, and AC reached breakthrough time in 1.1, 27.0, and 50.7 h, respectively. BC700 had higher TCE adsorption capacity than BC300 due to its higher surface area, nonpolarity, and aromaticity. The sorption capacities of AC (774.0 mg g−1 and BC700 (515.1 mg g−1 were 21.6 and 14.4 times higher than that of BC300 (35.9 mg g−1. The lower desorption rate of TCE from BC300 than BC700 and AC may be attributed to the strong binding/partition of TCE to the noncarbonized part of BC. Thomas model also adequately described the adsorption data indicating interphase mass transfer. Overall, AC showed best efficiency for removing TCE from water in column experiments. However, although sorption and desorption capabilities of BC700 were a little lower than AC, it is still a good alternative for AC to remove organic contaminants such as TCE from water due to its cost-effectiveness.

  2. Purification of monoclonal antibodies from whole hybridoma fermentation broth by fluidized bed adsorption.

    Science.gov (United States)

    Thömmes, J; Halfar, M; Lenz, S; Kula, M R

    1995-02-01

    To achive the coarse purification of a monoclonal antibody from whole hybridoma fermentation broth a fluidized bed cation exchange process was used. The procedure consisted of application of the crude sample and washing of the bed in a fluidized mode and elution in a fixed bed mode. A completely clarified eluate was obtained with purification factors between 4 and 8 and a concentration of the desired product (monoclonal antibody) by a factor of more than 3 was achived. Thus, a combination of the three early steps of the downstream process clarification, concentration and coarse purification was possible. Two different materials were tested: a commercially available agarose-based matrix (Stream-line-SP), and a self-derivatized material based on controlled-pore glass (Bioran). Initial experiments were performed to describe the fluidization of the glass material. Comparison with the agarose material showed several differences, the agarose matrix allowing liquid flow closer to plug flow than the glass material. Increased backmixing in the liquid phase was detected when fluidizing the glass adsorbent compared with the agarose-based matrix. Despite this fact, comparison of the two materials with respect to antibody binding and elution demonstrated a similar performance. (c) 1995 John Wiley & Sons, Inc.

  3. Optimal performance of single-column chromatography and simulated moving bed processes for the separation of optical isomers

    Science.gov (United States)

    Medi, Bijan; Kazi, Monzure-Khoda; Amanullah, Mohammad

    2013-06-01

    Chromatography has been established as the method of choice for the separation and purification of optically pure drugs which has a market size of about 250 billion USD. Single column chromatography (SCC) is commonly used in the development and testing phase of drug development while multi-column Simulated Moving Bed (SMB) chromatography is more suitable for large scale production due to its continuous nature. In this study, optimal performance of SCC and SMB processes for the separation of optical isomers under linear and overloaded separation conditions has been investigated. The performance indicators, namely productivity and desorbent requirement have been compared under geometric similarity for the separation of a mixture of guaifenesin, and Tröger's base enantiomers. SCC process has been analyzed under equilibrium assumption i.e., assuming infinite column efficiency, and zero dispersion, and its optimal performance parameters are compared with the optimal prediction of an SMB process by triangle theory. Simulation results obtained using actual experimental data indicate that SCC may compete with SMB in terms of productivity depending on the molecules to be separated. Besides, insights into the process performances in terms of degree of freedom and relationship between the optimal operating point and solubility limit of the optical isomers have been ascertained. This investigation enables appropriate selection of single or multi-column chromatographic processes based on column packing properties and isotherm parameters.

  4. Amino-functionalized mesoporous MCM-41 silica as an efficient adsorbent for water treatment: batch and fixed-bed column adsorption of the nitrate anion

    Science.gov (United States)

    Ebrahimi-Gatkash, Mehdi; Younesi, Habibollah; Shahbazi, Afsaneh; Heidari, Ava

    2015-11-01

    In the present study, amino-functionalized Mobil Composite Material No. 41 (MCM-41) was used as an adsorbent to remove nitrate anions from aqueous solutions. Mono-, di- and tri-amino functioned silicas (N-MCM-41, NN-MCM-41 and NNN-MCM-41) were prepared by post-synthesis grafting method. The samples were characterized by means of X-ray powder diffraction, FTIR spectroscopy, thermogravimetric analysis, scanning electron microscopy and nitrogen adsorption-desorption. The effects of pH, initial concentration of anions, and adsorbent loading were examined in batch adsorption system. Results of adsorption experiments showed that the adsorption capacity increased with increasing adsorbent loading and initial anion concentration. It was found that the Langmuir mathematical model indicated better fit to the experimental data than the Freundlich. According to the constants of the Langmuir equation, the maximum adsorption capacity for nitrate anion by N-MCM-41, NN-MCM-41 and NNN-MCM-41 was found to be 31.68, 38.58 and 36.81 mg/g, respectively. The adsorption kinetics were investigated with pseudo-first-order and pseudo-second-order model. Adsorption followed the pseudo-second-order rate kinetics. The coefficients of determination for pseudo-second-order kinetic model are >0.99. For continuous adsorption experiments, NNN-MCM-41 adsorbent was used for the removal of nitrate anion from solutions. Breakthrough curves were investigated at different bed heights, flow rates and initial nitrate anion concentrations. The Thomas and Yan models were utilized to calculate the kinetic parameters and to predict the breakthrough curves of different bed height. Results from this study illustrated the potential utility of these adsorbents for nitrate removal from water solution.

  5. Design, fabrication and initial evaluation of an upflow fixed-bed adsorption column for lead (Pb2+) using Carica papaya seeds

    International Nuclear Information System (INIS)

    The study is about the adsorption pf lead (Pb2+) using Carica papaya as biosorbent in an upflow continuous fixed-bed adsorption column. A column was designed and fabricated which was used in the experiment. It aimed to determine the effect of flowrates in the adsorption mechanism of the biosorbent. Three flowrates were used in the experiment: 100 mL/min, 150 mL/min, and 200 mL/min. A solution of 100 ppm of unbuffered lead was allowed to pass through a bed of biosorbent that has a length of 15 cm and the amount of lead ions was measured using flame atomic absorption spectroscopy in terms of residual concentration of lead in the outlet stream. The result showed that the 100 mL/min flowrate had the lowest amount of residual concentration measured compared to the 150 mL/min and 200 mL/min. This means that the 100 mL/min had the most lead ions adsorbed. Statistical test like the one-factor anova and t-test were also done in the research. Anova result showed that the flowrate has significant effect in the adsorption of lead ions of the biosorbent while the t-test results showed that the 100 ml/min is the most effective flowrate wherein the bed had adsorbed the most amounts of ions. (Author)

  6. Solid-phase microextraction/gas chromatography-mass spectrometry method optimization for characterization of surface adsorption forces of nanoparticles.

    Science.gov (United States)

    Omanovic-Miklicanin, Enisa; Valzacchi, Sandro; Simoneau, Catherine; Gilliland, Douglas; Rossi, Francois

    2014-10-01

    A complete characterization of the different physico-chemical properties of nanoparticles (NPs) is necessary for the evaluation of their impact on health and environment. Among these properties, the surface characterization of the nanomaterial is the least developed and in many cases limited to the measurement of surface composition and zetapotential. The biological surface adsorption index approach (BSAI) for characterization of surface adsorption properties of NPs has recently been introduced (Xia et al. Nat Nanotechnol 5:671-675, 2010; Xia et al. ACS Nano 5(11):9074-9081, 2011). The BSAI approach offers in principle the possibility to characterize the different interaction forces exerted between a NP's surface and an organic--and by extension biological--entity. The present work further develops the BSAI approach and optimizes a solid-phase microextraction gas chromatography-mass spectrometry (SPME/GC-MS) method which, as an outcome, gives a better-defined quantification of the adsorption properties on NPs. We investigated the various aspects of the SPME/GC-MS method, including kinetics of adsorption of probe compounds on SPME fiber, kinetic of adsorption of probe compounds on NP's surface, and optimization of NP's concentration. The optimized conditions were then tested on 33 probe compounds and on Au NPs (15 nm) and SiO2 NPs (50 nm). The procedure allowed the identification of three compounds adsorbed by silica NPs and nine compounds by Au NPs, with equilibrium times which varied between 30 min and 12 h. Adsorption coefficients of 4.66 ± 0.23 and 4.44 ± 0.26 were calculated for 1-methylnaphtalene and biphenyl, compared to literature values of 4.89 and 5.18, respectively. The results demonstrated that the detailed optimization of the SPME/GC-MS method under various conditions is a critical factor and a prerequisite to the application of the BSAI approach as a tool to characterize surface adsorption properties of NPs and therefore to draw any further

  7. Solid-phase microextraction/gas chromatography-mass spectrometry method optimization for characterization of surface adsorption forces of nanoparticles.

    Science.gov (United States)

    Omanovic-Miklicanin, Enisa; Valzacchi, Sandro; Simoneau, Catherine; Gilliland, Douglas; Rossi, Francois

    2014-10-01

    A complete characterization of the different physico-chemical properties of nanoparticles (NPs) is necessary for the evaluation of their impact on health and environment. Among these properties, the surface characterization of the nanomaterial is the least developed and in many cases limited to the measurement of surface composition and zetapotential. The biological surface adsorption index approach (BSAI) for characterization of surface adsorption properties of NPs has recently been introduced (Xia et al. Nat Nanotechnol 5:671-675, 2010; Xia et al. ACS Nano 5(11):9074-9081, 2011). The BSAI approach offers in principle the possibility to characterize the different interaction forces exerted between a NP's surface and an organic--and by extension biological--entity. The present work further develops the BSAI approach and optimizes a solid-phase microextraction gas chromatography-mass spectrometry (SPME/GC-MS) method which, as an outcome, gives a better-defined quantification of the adsorption properties on NPs. We investigated the various aspects of the SPME/GC-MS method, including kinetics of adsorption of probe compounds on SPME fiber, kinetic of adsorption of probe compounds on NP's surface, and optimization of NP's concentration. The optimized conditions were then tested on 33 probe compounds and on Au NPs (15 nm) and SiO2 NPs (50 nm). The procedure allowed the identification of three compounds adsorbed by silica NPs and nine compounds by Au NPs, with equilibrium times which varied between 30 min and 12 h. Adsorption coefficients of 4.66 ± 0.23 and 4.44 ± 0.26 were calculated for 1-methylnaphtalene and biphenyl, compared to literature values of 4.89 and 5.18, respectively. The results demonstrated that the detailed optimization of the SPME/GC-MS method under various conditions is a critical factor and a prerequisite to the application of the BSAI approach as a tool to characterize surface adsorption properties of NPs and therefore to draw any further

  8. A mass transfer model for the fixed-bed adsorption of ferulic acid onto a polymeric resin: axial dispersion and intraparticle diffusion.

    Science.gov (United States)

    Davila-Guzman, Nancy E; Cerino-Córdova, Felipe J; Soto-Regalado, Eduardo; Loredo-Cancino, Margarita; Loredo-Medrano, José A; García-Reyes, Refugio B

    2016-08-01

    In this study, amberlite XAD-16 (XAD-16) bed column system was used to remove ferulic acid (FA) from aqueous solutions. Laboratory-scale column experiments were conducted in downflow fixed bed at initial FA concentration of 1 g/L, initial pH 3, and 25°C. The performance of the adsorbent bed under different flow rates (1.3-7.7 mL/min) was studied. The bed utilization efficiency was in the range of 64.64-72.21% at the studied flow rates. A mass transfer model considering both axial dispersion and intraparticle diffusion was developed to predict the breakthrough curves of FA adsorption on XAD-16. This model predicted the experimental data better than Bohart-Adams model and Thomas model, based on the low deviation between predicted and experimental data. The axial dispersion coefficient value varied from 6.45 × 10(-6) to 1.10 × 10(-6) m(2)/s at flow rate from 1.3 to 7.7 mL/min, whereas the intraparticle diffusion coefficient was 1.04 × 10(-10) m(2)/s, being this last resistance the rate-limiting step. In conclusion, axial dispersion and intraparticle diffusion phenomena play the major role in predicting the adsorption of FA onto XAD-16 in fixed-bed columns.

  9. Performance investigation of a waste heat-driven 3-bed 2-evaporator adsorption cycle for cooling and desalination

    KAUST Repository

    Thu, Kyaw

    2016-06-13

    Environment-friendly adsorption (AD) cycles have gained much attention in cooling industry and its applicability has been extended to desalination recently. AD cycles are operational by low-temperature heat sources such as exhaust gas from processes or renewable energy with temperatures ranging from 55 °C to 85 °C. The cycle is capable of producing two useful effects, namely cooling power and high-grade potable water, simultaneously. This article discusses a low temperature, waste heat-powered adsorption (AD) cycle that produces cooling power at two temperature-levels for both dehumidification and sensible cooling while providing high-grade potable water. The cycle exploits faster kinetics for desorption process with one adsorber bed under regeneration mode while full utilization of the uptake capacity by adsorbent material is achieved employing two-stage adsorption via low-pressure and high-pressure evaporators. Type A++ silica gel with surface area of 863.6 m2/g and pore volume of 0.446 cm3/g is employed as adsorbent material. A comprehensive numerical model for such AD cycle is developed and the performance results are presented using assorted hot water and cooling water inlet temperatures for various cycle time arrangements. The cycle is analyzed in terms of key performance indicators i.e.; the specific cooling power (SCP), the coefficient of performance (COP) for both evaporators and the overall system, the specific daily water production (SDWP) and the performance ratio (PR). Further insights into the cycle performance are scrutinized using a Dühring diagram to depict the thermodynamic states of the processes as well as the vapor uptake behavior of adsorbent. In the proposed cycle, the adsorbent materials undergo near saturation conditions due to the pressurization effect from the high pressure evaporator while faster kinetics for desorption process is exploited, subsequently providing higher system COP, notably up to 0.82 at longer cycle time while the

  10. An Integrated Theory of Adsorption and Partition Mechanism and Eash Contribution to Solute Retention in Reversed Phase Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    耿信笃; 弗莱德依瑞格涅尔

    2003-01-01

    With the combination of the the stoichiometric displacement model for retention (SDM-R) in reversed phase liquid chromatography (RPLC) and the stoichiometric displacement model for adsorption (SDM-A) in physical chemistry,the total number of moles of the re-solvated methanol of stationary phase side.nr,and that of solute side in the mobile phase,q,corresponding the one mole of the desorbing solute,were separately determined and referred as the characterization parameters of the contributions of the adsorption mechanism and partition mechanism to the solute retention,respectively.A chromatographic system of insulin,using mobile phase consisting of the pseudo-homologue of alcohols(methanol,ethanol and 2-propanol)-water and trifluoroacetic acid was employed.The maximum number of the methanol layers on the stationary phase surface was found to be 10.6,only 3 of which being valid in usual RPLC,traditionally referred as a volume process in partition mechanism.However,it still follows the SDM-R.Both of q and nr of insulin were found not to be zero,indicating that the retention mechanism of insulin is a mixed mode of partition mechanism and adsorption mechanism.When methanol is used as the organic modifier,the ratio of q/nr was 1.13,indicating the contribution to insulin retention due to partition mechanism being a bit greater than that due to adsorption mechanism.A linear relationship between q,or nr and the carbon number of the pseudo-homologue in the mobile phase was also found.As a methodology for investigating the retention mechanism retention and behavior of biopolymers.a homologue of organic solvents as the organic modifier in mobile phase has also been explored.

  11. Automated methods for accurate determination of the critical velocity of packed bed chromatography.

    Science.gov (United States)

    Chang, Yu-Chih; Gerontas, Spyridon; Titchener-Hooker, Nigel J

    2012-01-01

    Knowing the critical velocity (ucrit) of a chromatography column is an important part of process development as it allows the optimization of chromatographic flow conditions. The conventional flow step method for determining ucrit is prone to error as it depends heavily on human judgment. In this study, two automated methods for determining ucrit have been developed: the automatic flow step (AFS) method and the automatic pressure step (APS) method. In the AFS method, the column pressure drop is monitored upon application of automated incremental increases in flow velocity, whereas in the APS method the flow velocity is monitored upon application of automated incremental increases in pressure drop. The APS method emerged as the one with the higher levels of accuracy, efficiency and ease of application having the greater potential to assist defining the best operational parameters of a chromatography column.

  12. Validity of intra-particle models of mass transfer kinetics in the analysis of a fin-tube type adsorption bed

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sang Woo; Ahn, Sang Hyeok; Chung, Jae Dong [Sejong University, Seoul (Korea, Republic of); Kwon, Oh Kyung [Korea Institute of Industrial Technology, Chonan (Korea, Republic of)

    2014-05-15

    This study presents a numerical investigation of the heat and mass transfer kinetics of a fin-tube type adsorption bed using a two dimensional numerical model with silica-gel/water as the adsorbent and refrigerant pair. The performance is strongly affected by the heat and mass transfer in the adsorption bed, but the details of the mass transfer kinetics remain unclear. The validity of intra-particle models used to simulate mass transfer kinetics such as the equilibrium, LDF, and solid-diffusion models are examined, and the valid ranges of the diffusion ratio for each model are proposed. An intra-particle diffusion model should be carefully implemented; otherwise, seriously distorted results may be produced, i.e., over-estimation for the equilibrium model and under estimation for the LDF model.

  13. Robust design of adenovirus purification by two-column, simulated moving-bed, size-exclusion chromatography.

    Science.gov (United States)

    Nestola, Piergiuseppe; Silva, Ricardo J S; Peixoto, Cristina; Alves, Paula M; Carrondo, Manuel J T; Mota, José P B

    2015-11-10

    A simple, yet efficient, two-column simulated moving-bed (2CSMB) process for purifying adenovirus serotype 5 (Ad5) by size-exclusion chromatography (SEC) is presented and validated experimentally, and a general procedure for its robust design under parameter uncertainty is described. The pilot-scale run yielded a virus recovery of 86 percent and DNA and HCP clearances of 90 and 89 percent, respectively, without any fine tuning of the operating parameters. This performance compares very favorably against that of single-column batch chromatography for the same volume of size-exclusion resin. To improve the robustness of the 2CSMB-SEC process the best set of operating parameters is selected only among candidate solutions that are robust feasible, that is, remain feasible for all parameter perturbations within their uncertainty intervals. This robust approach to optimal design replaces the nominal problem by a worst case problem. Computational tractability is ensured by formulating the robust design problem with only the vertices of the uncertainty region that have the worst effect on the product purity and recovery. The robust design is exemplified on the case where the column volume and interparticle porosity are subject to uncertainty. As expected, to increase the robustness of the 2CSMB-SEC process it is necessary to reduce its productivity and increase its solvent consumption. Nevertheless, the design solution given by our robust approach is the least detrimental of all feasible operating conditions for the 2CSMB-SEC process.

  14. Adsorption Kinetics of Dibenzofuran in Activated Carbon Packed Bed%二苯并呋喃在活性炭床层中的吸附动力学

    Institute of Scientific and Technical Information of China (English)

    李湘; 李忠; 罗灵爱

    2008-01-01

    The adsorption of dibenzofuran (DBF) on three commercial granular activated carbons (GAC) was in-vestigated to correlate the adsorption equilibrium and kinetics with the morphological characteristics of activated carbons. Breakthrough experiment was conducted to determine the isotherm and kinetics of dibenzofuran on the ac-tivated carbons. All the experiment runs were performed in a fixed bed with a process temperature of 368 K. The effects of adsorbent morphological properties on the kinetics of the adsorption process were studied. The equilib-rium data are found satisfactory fitted to the Langmuir isotherm. An intraparticle diffusion model based on the ob- tained Langmuir isotherm was developed for predicting the fixed bed adsorption of dibenzofuran. The result indi- cated that this model fit all the breakthrough curves well. The surface diffusion coefficients of dibenzofuran on the activated carbon are calculated, and a relationship with the microperosity is found. As it was expected, the diben-zofuran molecule finds more kinetic restrictions for the diffusion in those carbons with narrower pore diameter.

  15. An overview of research progress of adsorption and desorption of coal-Bed methane%煤层气吸附解吸研究进展综述

    Institute of Scientific and Technical Information of China (English)

    常广涛; 王一帆; 董特特

    2015-01-01

    对于煤层气吸附、解吸特征及机理的研究,是揭示煤层气成藏机理及高效开发煤层气的基础。通过对国内外文献资料的调研,详细论述了煤层气吸附解吸的机理和过程,介绍了影响煤层气吸附与解吸的因素以及各种煤层气吸附的数学模型,提出了煤层气吸附与解吸研究中存在的问题,进而为煤层气藏的高效、合理开发奠定理论基础。%The characteristics and mechanism research of coal-bed methane adsorption and desorption is the foundation of efficient development of coal-bed methane. The mechanism and process of adsorption and desorption of coal-bed methane are discussed in detail. The mathematical model and influencing factors as well as problems among the research are given. These can help to provide a theoretical foundation for the efficient,rational exploitation of coal-bed methane.

  16. Revisiting the Separation of Ferrocene and Acetylferrocene by Adsorption Chromatography: Adding a Third Component

    Science.gov (United States)

    Hwa, Rebecca; Weizman, Haim

    2007-01-01

    The separation of ferrocene and acetylferrocene by column chromatography is a widely used experiment in undergraduate organic labs. The experiment was expanded into a three-component mixture to increase the challenge of the experiment and to make TLC analysis necessary. (Contains 2 figures.)

  17. Kinetics and adsorption isotherm of C-phycocyanin from Spirulina platensis on ion-exchange resins

    OpenAIRE

    Sala, L; F. S. Figueira; G. P. Cerveira; C. C. Moraes; S. J. Kalil

    2014-01-01

    C-phycocyanin is a natural blue dye extracted from Spirulina platensis, which has many applications in the food and pharmaceutical industries. In this paper the effect of pH and temperature on the adsorption of C-phycocyanin onto two different ion exchange resins (Streamline DEAE and Streamline Q XL) for expanded bed adsorption chromatography was investigated. Moreover, the kinetics and adsorption isotherm were evaluated. The equilibrium for the Q XL matrix was reached after 60 min, while for...

  18. High-performance liquid chromatography as a technique to determine protein adsorption onto hydrophilic/hydrophobic surfaces.

    Science.gov (United States)

    Huang, Tongtong; Anselme, Karine; Sarrailh, Segolene; Ponche, Arnaud

    2016-01-30

    The purpose of this study is to evaluate the potential of simple high performance liquid chromatography (HPLC) setup for quantification of adsorbed proteins on various type of plane substrates with limited area (HPLC were reliable. By simple adsorption test at the contact of hydrophilic (glass) and hydrophobic (polydimethylsiloxane: PDMS) surfaces, kinetics of adsorption were determined and amounts of adsorbed bovine serum albumin, myoglobin and lysozyme were obtained: as expected for each protein, the amount adsorbed at the plateau on glass (between 0.15 μg/cm(2) and 0.4 μg/cm(2)) is lower than for hydrophobic PDMS surfaces (between 0.45 μg/cm(2) and 0.8 μg/cm(2)). These results were consistent with bicinchoninic acid protein determination. According to ICH guidelines, both Reversed Phase and Size Exclusion HPLC can be validated for quantification of adsorbed protein. However, we consider the size exclusion approach more interesting in this field because additional informations can be obtained for aggregative proteins. Indeed, monomer, dimer and oligomer of bovine serum albumin (BSA) were observed in the chromatogram. On increasing the temperature, we found a decrease of peak intensity of bovine serum albumin as well as the fraction of dimer and oligomer after contact with PDMS and glass surface. As the surface can act as a denaturation parameter, these informations can have a huge impact on the elucidation of the interfacial behavior of protein and in particular for aggregation processes in pharmaceutical applications.

  19. Combination of granular activated carbon adsorption and deep-bed filtration as a single advanced wastewater treatment step for organic micropollutant and phosphorus removal.

    Science.gov (United States)

    Altmann, Johannes; Rehfeld, Daniel; Träder, Kai; Sperlich, Alexander; Jekel, Martin

    2016-04-01

    Adsorption onto granular activated carbon (GAC) is an established technology in water and advanced wastewater treatment for the removal of organic substances from the liquid phase. Besides adsorption, the removal of particulate matter by filtration and biodegradation of organic substances in GAC contactors has frequently been reported. The application of GAC as both adsorbent for organic micropollutant (OMP) removal and filter medium for solids retention in tertiary wastewater filtration represents an energy- and space saving option, but has rarely been considered because high dissolved organic carbon (DOC) and suspended solids concentrations in the influent of the GAC adsorber put a significant burden on this integrated treatment step and might result in frequent backwashing and unsatisfactory filtration efficiency. This pilot-scale study investigates the combination of GAC adsorption and deep-bed filtration with coagulation as a single advanced treatment step for simultaneous removal of OMPs and phosphorus from secondary effluent. GAC was assessed as upper filter layer in dual-media downflow filtration and as mono-media upflow filter with regard to filtration performance and OMP removal. Both filtration concepts effectively removed suspended solids and phosphorus, achieving effluent concentrations of 0.1 mg/L TP and 1 mg/L TSS, respectively. Analysis of grain size distribution and head loss within the filter bed showed that considerable head loss occurred in the topmost filter layer in downflow filtration, indicating that most particles do not penetrate deeply into the filter bed. Upflow filtration exhibited substantially lower head loss and effective utilization of the whole filter bed. Well-adsorbing OMPs (e.g. benzotriazole, carbamazepine) were removed by >80% up to throughputs of 8000-10,000 bed volumes (BV), whereas weakly to medium adsorbing OMPs (e.g. primidone, sulfamethoxazole) showed removals <80% at <5,000 BV. In addition, breakthrough behavior was

  20. Combination of granular activated carbon adsorption and deep-bed filtration as a single advanced wastewater treatment step for organic micropollutant and phosphorus removal.

    Science.gov (United States)

    Altmann, Johannes; Rehfeld, Daniel; Träder, Kai; Sperlich, Alexander; Jekel, Martin

    2016-04-01

    Adsorption onto granular activated carbon (GAC) is an established technology in water and advanced wastewater treatment for the removal of organic substances from the liquid phase. Besides adsorption, the removal of particulate matter by filtration and biodegradation of organic substances in GAC contactors has frequently been reported. The application of GAC as both adsorbent for organic micropollutant (OMP) removal and filter medium for solids retention in tertiary wastewater filtration represents an energy- and space saving option, but has rarely been considered because high dissolved organic carbon (DOC) and suspended solids concentrations in the influent of the GAC adsorber put a significant burden on this integrated treatment step and might result in frequent backwashing and unsatisfactory filtration efficiency. This pilot-scale study investigates the combination of GAC adsorption and deep-bed filtration with coagulation as a single advanced treatment step for simultaneous removal of OMPs and phosphorus from secondary effluent. GAC was assessed as upper filter layer in dual-media downflow filtration and as mono-media upflow filter with regard to filtration performance and OMP removal. Both filtration concepts effectively removed suspended solids and phosphorus, achieving effluent concentrations of 0.1 mg/L TP and 1 mg/L TSS, respectively. Analysis of grain size distribution and head loss within the filter bed showed that considerable head loss occurred in the topmost filter layer in downflow filtration, indicating that most particles do not penetrate deeply into the filter bed. Upflow filtration exhibited substantially lower head loss and effective utilization of the whole filter bed. Well-adsorbing OMPs (e.g. benzotriazole, carbamazepine) were removed by >80% up to throughputs of 8000-10,000 bed volumes (BV), whereas weakly to medium adsorbing OMPs (e.g. primidone, sulfamethoxazole) showed removals <80% at <5,000 BV. In addition, breakthrough behavior was

  1. Studies of Adsorption of Heavy Metals onto Spent Coffee Ground: Equilibrium, Regeneration, and Dynamic Performance in a Fixed-Bed Column

    Directory of Open Access Journals (Sweden)

    N. E. Davila-Guzman

    2016-01-01

    Full Text Available Equilibrium and dynamic adsorption of heavy metals onto spent coffee ground (SCG were studied. The equilibrium adsorption of Cd2+, Cu2+, and Pb2+ in a batch system was modeled by an ion-exchange model (IEM based on an ion-exchange of heavy metals with calcium and protons bonded to active sites on SCG surface. The maximum amount of adsorbed metal ions obtained using the IEM was 0.12, 0.21, and 0.32 mmol/g of Cd2+, Cu2+, and Pb2+, respectively. Regeneration of SCG was evaluated using citric acid, calcium chloride, and nitric acid. The observed trend of desorption efficiency through four adsorption-desorption cycles was HNO3 > CaCl2 > C6H8O7. The effect of process variables such as flow rate and bed height during the dynamic adsorption was evaluated. Moreover, the applicability of a mass transfer model based on external mass transfer resistance, axial dispersion, and ion-exchange isotherm was evaluated, and the results were in good agreement with the experimental data for the adsorption in SCG packed column. The sensitivity analysis of the model parameters showed that axial dispersion coefficient is the most significant parameter in the dynamic simulation. The results obtained showed the potential of SCG as a low-cost material for wastewater metal removal in continuous systems.

  2. Adsorption in a Fixed-Bed Column and Stability of the Antibiotic Oxytetracycline Supported on Zn(II-[2-Methylimidazolate] Frameworks in Aqueous Media.

    Directory of Open Access Journals (Sweden)

    Janine dos Santos Ferreira da Silva

    Full Text Available A metal-organic framework, Zn-[2-methylimidazolate] frameworks (ZIF-8, was used as adsorbent material to remove different concentrations of oxytetracycline (OTC antibiotic in a fixed-bed column. The OTC was studied at concentrations of 10, 25 and 40 mg L(-1. At 40 mg L(-1, the breakthrough point was reached after approximately 10 minutes, while at 10 and 25 mg L(-1 this point was reached in about 30 minutes. The highest removal rate of 60% for the 10 mg L(-1 concentration was reached after 200 minutes. The highest adsorption capacity (28.3 mg g(-1 was attained for 25 mg L(-1 of OTC. After the adsorption process, a band shift was observed in the UV-Vis spectrum of the eluate. Additional studies were carried out to determine the cause of this band shift, involving a mass spectrometry (MS analysis of the supernatant liquid during the process. This investigation revealed that the main route of adsorption consisted of the coordination of OTC with the metallic zinc centers of ZIF-8. The materials were characterized by thermal analysis (TA, scanning electron microscopy (SEM, powder X-ray diffraction (XRD, and infrared spectroscopy (IR before and after adsorption, confirming the presence of OTC in the ZIF-8 and the latter's structural stability after the adsorption process.

  3. Effects of a malfunctional column on conventional and FeedCol-simulated moving bed chromatography performance.

    Science.gov (United States)

    Song, Ji-Yeon; Oh, Donghoon; Lee, Chang-Ha

    2015-07-17

    The effects of a malfunctional column on the performance of a simulated moving bed (SMB) process were studied experimentally and theoretically. The experimental results of conventional four-zone SMB (2-2-2-2 configuration) and FeedCol operation (2-2-2-2 configuration with one feed column) with one malfunctional column were compared with simulation results of the corresponding SMB processes with a normal column configuration. The malfunctional column in SMB processes significantly deteriorated raffinate purity. However, the extract purity was equivalent or slightly improved compared with the corresponding normal SMB operation because the complete separation zone of the malfunctional column moved to a lower flow rate range in zones II and III. With the malfunctional column configuration, FeedCol operation gave better experimental performance (up to 7%) than conventional SMB operation because controlling product purity with FeedCol operation was more flexible through the use of two additional operating variables, injection time and injection length. Thus, compared with conventional SMB separation, extract with equivalent or slightly better purity could be produced from FeedCol operation even with a malfunctional column, while minimizing the decrease in raffinate purity (less than 2%).

  4. Dependence of Elution Curve and Adsorption Isotherms of Insulin on composition of Mobile Phase of Frontal Analysis in Reversed Phase Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    耿信笃; 弗莱德依瑞格涅尔

    2003-01-01

    With frontal analysis(FA),the dependence of adsorption isotherms of insulin on the composition of mobile phase in reversed phase liquid chromatography (RPLC) has been investigated,This is also a good example to employ the stoichiometric displacement theory (SDT) for ivestigating solute adsorption in physical chemistry.Six kinds of mobile phase in RPLC were employed to study the effects on the elution curves and adsorption isotherms of insulin.the key points of this paper are:(1) the stability of insulin due to delay time after preparing,the organic solvent concentration,the kind and the concentration of ion-pairing agent in mobile phase were found to affect both elution curve and adsorption isotherm very seriously.(2)To obtain a valid and comparable result,the composition of the mobile phase employed in FA must be as same as possible to that in usual RPLC of either analytical scale or preparative purpose.(3)Langmuir Equation and the SDT were employed to imitate these obtained adsorption isotherms.The expression for solute adsorption from solution of the SDT was found to have a better elucidation to the insulin adsorption from mobile phase in RPLC.

  5. Low-coverage adsorption properties of the metal-organic framework MIL-47 studied by pulse chromatography and Monte Carlo simulations.

    Science.gov (United States)

    Finsy, Vincent; Calero, Sofia; García-Pérez, Elena; Merkling, Patrick J; Vedts, Gill; De Vos, Dirk E; Baron, Gino V; Denayer, Joeri F M

    2009-05-14

    Low-coverage adsorption properties of the metal-organic framework MIL-47 were determined by a combined experimental and simulation study. Henry constants and low coverage adsorption enthalpies of C5-C8 linear and branched alkanes, cyclohexane and benzene were measured from 120 to 240 degrees C using pulse gas chromatography. An adapted force field for linear and branched alkanes in MIL-47 was used to compute the adsorption properties of those molecules. A new set of charges was developed for simulations with benzene in MIL-47. The adsorption enthalpy of linear alkanes increases with about 7.6 kJ mol(-1) per additional -CH2- group. Henry adsorption constants of iso-alkanes are slightly lower than those of the linear chains but the MIL-47 framework is not imposing steric constraints on the branched chains. Benzene and cyclohexane are adsorbed less strongly than n-hexane as they have less hydrogen atoms. For the studied non-polar molecules, the adsorption energies are dominated by van der Waals interactions and benzene adsorption is additionally influenced by Coulombic interactions. The simulated tendencies are in good agreement with the experiments. PMID:19421556

  6. Serum acetaminophen assay using activated charcoal adsorption and gas chromatography without derivatization.

    Science.gov (United States)

    Jeevanandam, M; Novic, B; Savich, R; Wagman, E

    1980-01-01

    A quantitative assay of acetaminophen in serum has been developed. The drug, together with an internal standard 2-acetamidophenol, is adsorbed on activated charcoal and then extracted into a mixture of ethyl acetate and isopropanol. This extract is then analyzed, without any derivatization, by gas chromatography. The isothermal analysis yielded a good, highly reproducible separation. The drug peak was symmetrical and without any tailing. The peak height response ratio was found to be linear with concentrations ranging from 25-500 ng/L. No interference was observed with the various drugs or metabolites which are commonly encountered in human serum. PMID:7421146

  7. Simulation assessment of continuous simulating moving bed chromatography process with partial feed and new strategy with partial feed

    Directory of Open Access Journals (Sweden)

    H. Khan

    2009-09-01

    Full Text Available Partial Feed simulating moving bed (SMB has proved to be more efficient in binary separation performance (purity, recovery, productivity because of its two additional degrees of freedom, namely feed length and feed time, as compared to classical SMB process. The binary separation of dextran T6 and fructose with linear isotherm is modeled with Aspen Chromatography simulator in a four zone SMB with one column per zone for both normal-feed and Partial Feed. Increase in number of feed length and feed time in the cycle plays a very important role in the separation performance with Partial Feed. In addition, the effect of mode of operation (early or late introduction of increase in number of feed length in the cycle on product purity and recovery is also investigated. Furthermore, the binary separation system is designed with the safety margin method and the optimum operating parameters for simulation are calculated with triangle theory. Finally, a new strategy with Partial Feed is developed, showing improved separation performance relative to the basic four-zone SMB with regard to extract stream purity and recovery. The results of the proposed study can served as a useful summary of Partial Feed operation.

  8. Thermal treatment of Lloydminster heavy oil: yield and product separation by adsorption chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, P.K.; Sastre, H.; Chornet, E.; Kotlyar, L.S.; Ripmeester, J.A.; Overend, R.P. (University of Sherbrooke, Quebec (Canada). Dept. of Chemical Engineering)

    1989-09-01

    The effect of thermal treatment on Lloydminster heavy oil has been studied under pyrolytic, catalytic and non-catalytic hydropyrolysis and hydrogen donor solvent (tetralin) regimes using a batch autoclave. Product yields are reported for each type of reaction regime in terms of gases, maltenes, asphaltenes and toluene insoluble organic matter (coke). The maltene fraction was further separated by column chromatography into four chemical compound types namely: saturates, mono- and di-aromatics, polyaromatics and polars. The asphaltene fraction was also separated in four fractions by column chromatography by elution with solvents of increasing polarity. These fractions were characterized by FTIR and {sup 1}{sup 3}C NMR. The evolution of these fractions was studied as a function of the treatment. Tetralin was found to be effective in eliminating coke and increasing the maltene content relative to other treatments. It has been observed that the decrease of polyaromatic and polar species in the maltenes results in a corresponding increase of saturates. The asphaltene yield also decreases with thermal treatment. In all treatments the asphaltene fractions rich in polar and highly functional groups decrease drastically. 34 refs., 7 figs., 2 tabs.

  9. 异步模拟移动床色谱的数值模拟%Numerical Simulation of Asynchronous Simulated Moving Bed Chromatography

    Institute of Scientific and Technical Information of China (English)

    卢建刚

    2004-01-01

    Asynchronous simulated moving bed chromatography(ASMBC),known also as the "VARICOL" process,is more efficient and flexible than the well-known and traditional simulated moving bed chromatography(SMBC).A detailed model of ASMBC,taking account of non-linear competitive isotherms,mass transfer parameters,and complex port switching schedule parameters,was developed to simulate the complex dynamics of ASMBC.The simulated performance is in close agreement with the experimental data of chiral separation reported in the literature.The simulation results show that ASMBC can achieve the performance similar to SMBC with fewer columns and can achieve better performance than SMBC with the same total column number.All design and operation parameters can be chosen correctly by numerical simulation.This detailed ASMBC model and the numerical technique are useful for design,operation,optimization and scale-up of ASMBC.

  10. 利用膨胀床吸附技术单步纯化分子伴侣—GroEL%Single-step Purification of Molecular Chaperone GroEL by Expanded Bed Chromatography

    Institute of Scientific and Technical Information of China (English)

    佟晓冬; 杨征; 董晓燕; 孙彦

    2003-01-01

    Expanded bed adsorption (EBA) is an integrative downstream processing technique for the purificationof biological substances directly from unclarified feedstock. In this study, molecular chaperone GroEL, an importantprotein folding helper both in vivo and in vitro, was purified by the single-step EBA technique from the unclarifiedhomogenate of recombinant E. coli cells. Compared with packed bed adsorption, the EBA technique provideda single-step approach to yield an electrophoretic purity of GroEL. After the homogenate loading and columnwashing in the expanded bed mode, the GroEL protein was recovered by stepwise salt-gradient elution in packed-bed or expanded-bed modes, respectively. The expanded-bed elution mode was found as efficient as the packed-bedmode in the purification of GroEL from cell disruptate.

  11. Adsorption Rate Models for Multicomponent Adsorption Systems

    Institute of Scientific and Technical Information of China (English)

    姚春才

    2004-01-01

    Three adsorption rate models are derived for multicomponent adsorption systems under either pore diffusion or surface diffusion control. The linear driving force (LDF) model is obtained by assuming a parabolic intraparticle concentration profile. Models I and Ⅱ are obtained from the parabolic concentration layer approximation. Examples are presented to demonstrate the usage and accuracy of these models. It is shown that Model I is suitable for batch adsorption calculations and Model Ⅱ provides a good approximation in fixed-bed adsorption processes while the LDF model should not be used in batch adsorption and may be considered acceptable in fixed-bed adsorption where the parameter Ti is relatively large.

  12. Center-cut separation of intermediately adsorbing target component by 8-zone simulated moving bed chromatography with internal recycle.

    Science.gov (United States)

    Kiwala, Dawid; Mendrella, Jadwiga; Antos, Dorota; Seidel-Morgenstern, Andreas

    2016-07-01

    An 8-zone simulated moving bed chromatography with internal recycle (8ZSMB-IR) has been designed for center-cut separation, that is, for isolating an intermediately adsorbed component out of a multicomponent mixture. The system consists of two integrated subunits and operates in a fully continuous manner. In the first subunit the feed mixture is split into two fractions containing either a single component or a binary mixture. The binary mixture is recycled through the internal raffinate or extract port into the second subunit, where the target product is isolated. Additionally, the solvent is also recycled internally. For a case study, the separation of a ternary mixture of cycloketones as a model system under weakly non-linear isotherm conditions has been investigated. A few novel configurations of the 8ZSMB-IR unit including the arrangement of the internal recycle of extract, raffinate and solvent streams between two subunits have been examined with respect to various performance indicators for the process realization. The unit performed best with the developed configuration when the internal raffinate stream was recycled and the solvent recycling loop was closed between the last and the first zone of the first subunit. That configuration has further been analyzed experimentally and numerically. On the basis of the results a strategy for determining reliable operating conditions for the 8ZSMB-IR process has been developed. The procedure exploited a model of the process dynamics, which was implemented to refine the isotherm coefficients and to quantify the mixing effect of the liquid stream inside the recycling loops. The upgraded model with the adjusted parameters has been validated based on experimental data and successfully applied for optimizing the operating conditions of the separation. PMID:27260199

  13. Application of Adsorption Potential Theory to Study on Adsorption-Desorption of Coal Bed Methane%吸附势理论在煤层气吸附解吸研究中的应用

    Institute of Scientific and Technical Information of China (English)

    姜伟; 吴财芳; 姜玮; 王聪; 陈召英; 杜严飞

    2011-01-01

    Taking the Jincheng anthracite coal as the study object, the methane and nitrogen adsorption and desorption experiments were conducted at 30 ℃. Based on the uniqueness of adsorption characteristic curve, according to the adsorption and desorption data of 30 ℃, with the adsorption potential theory as the basis, the methane isothermal adsorption curve at 50 ℃ was predicted. The results showed that the predicted curve and the site measured curve could be well fitted, the average absolute error of the predicted vaule was 0. 5 cm3/g and the average relative error was 3.12%. Meanwhile according to the adsorption feature curves of nitrogen and methane at 30 ℃, there would be a cross point at the corresponding pressure of 0. 61 MPa between the nitrogen and methane adsorption characteristic curves. Thus when the pressure was lower than 0. 61 MPa, the adsorption potential of nitrogen would be higher than the adsorption potential of the methane. The nitrogen injection would play a promotion role to improve the production of the coal bed methane. Therefore, a preliminary theoretical basis could be provided to determine the nitrogen injection pressure range during the N2-ECBM process of the coal reservoir.%以晋城无烟煤为研究对象,进行了30℃时煤对甲烷和氮气的吸附解吸试验.基于吸附特性曲线的唯一性特点,根据30℃甲烷的吸附解吸数据,以吸附势理论为依据,预测了50℃时甲烷的等温吸附曲线,结果表明预测曲线与实测曲线吻合良好,其预测值平均绝对误差为0.5 cm3/g,平均相对误差为3.12%.同时依据30℃时氮气和甲烷的吸附特性曲线,发现氮气和甲烷的吸附势对应压力在0.61 MPa时存在交点,表明压力低于0.61 MPa时氮气的吸附势高于甲烷的吸附势,此时注入氮气对提高煤层气的增产具有促进作用,这为煤储层在N2-ECBM(注氮增产法)过程中确定氮气的注气压力范围提供了初步的理论依据.

  14. Measurement of dynamic adsorption coefficient of Xe on coconut charcoal in CO2 streams by gas-solid chromatography

    International Nuclear Information System (INIS)

    This paper presents a method for measuring the dynamic adsorption coefficients of Xe on coconut charcoal II-2 in CO2 carrier streams by SP-2305E gas chromatograph with the thermal conductivity cell. The adsorption column is made of stainless steel (diameter 4 x 240 mm) packed with 60-80 mesh coconut charcoal II-2. The CO2 content in carrier streams is about 87%. Three groups of data of Xe dynamic adsorption coefficient were obtained at temperature 15.5 deg C, 31.5 deg C and 50.5 deg C by pulse injection respectively. Another group was obtained at temperature approx. 16 deg C by continueous injection. In addition, adsorption isotherms and adsorption isometrics were determined. In this experimental system, the adsorption heat of Xe on coconut charcoal II-2 is 2820 cal/mole

  15. Activity coefficients at infinite dilution of organic solutes in 1-hexyl-3-methylimidazolium trifluoroacetate and influence of interfacial adsorption using gas–liquid chromatography

    International Nuclear Information System (INIS)

    Highlights: • Activity coefficients at infinite dilution of organic solutes in [HMIM][TFA] were determined. • The contribution of interfacial adsorption to the retention mechanism was estimated. • The partial molar excess enthalpies and the solubility parameters of [HMIM][TFA] were calculated. -- Abstract: Activity coefficients at infinite dilution for a series of organic solutes in the ionic liquid 1-hexyl-3-methylimidazolium trifluoroacetate ([HMIM][TFA]) have been determined by gas–liquid chromatography at the temperature range from (303.15 to 363.15) K. The contribution of interfacial adsorption to the retention mechanism was estimated by changing the loading of ionic liquid in stationary phase. The partial molar excess enthalpies at infinite dilution and the solubility parameters of ionic liquid were also calculated from the experimental values of activity coefficients at infinite dilution

  16. A New Method for Determination of Adsorption and Desorption Coefficients of Pesticides with Soil Column Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The adsorption and desorption coefficients of atrazine, methiocarb and simazine on a sandy loam soil were measured in this study with soil column liquid chromatographic (SCLC) technique. The adsorption and desorption data of all the three pesticides followed Freundlich isotherms revealing the existence of hysteresis. In comparing with other methods, SCLC method showed some characteristics such as rapidity, online and accuracy.

  17. Photocatalytic degradation of mixed gaseous carbonyl compounds at low level on adsorptive TiO2/SiO2 photocatalyst using a fluidized bed reactor.

    Science.gov (United States)

    Zhang, Maolin; An, Taicheng; Fu, Jiamo; Sheng, Guoying; Wang, Xinming; Hu, Xiaohong; Ding, Xuejun

    2006-06-01

    An adsorptive silica-supported titania photocatalyst TiO(2)/SiO(2) was prepared by using nanosized titania (anatase) immobilized on silica gel by the sol-gel technique with the titanium tetra isopropoxide as the main raw material and acetic acid as the acid catalyst. Meanwhile the structure and properties of the TiO(2)/SiO(2) photocatalyst were studied by means of many modern analysis techniques such as TEM, XRD, and BET. Gas-solid heterogeneous photocatalytic decomposition of four carbonyl compounds mixture at low concentration levels over ultraviolet irradiated TiO(2)/SiO(2) photocatalyst were carried out with high degradation efficiencies in a coaxial triple-cylinder-type fluidized bed photocatalytic reactor, which provided efficient continuous contact of ultraviolet photons, silica-supported titania photocatalyst, and gaseous reactants. Experimental results showed that the photocatalyst had a high adsorption performance and a good photocatalytic activity for four carbonyl compounds mixture. Some factors influencing the photocatalytic decomposition of the mixed carbonyl compounds, i.e. the gas flowrate, relative humidity, concentration of oxygen, and illumination time, were discussed in detail. It is found that the photocatalytic reaction rate of four carbonyl compounds decreased in this order: propionaldehyde, acetone, acetaldehyde and formaldehyde.

  18. Simulation of adsorption process of low-concentration coal bed methane%低浓度煤层气吸附过程的模拟

    Institute of Scientific and Technical Information of China (English)

    施海珊; 王煤; 马睿

    2012-01-01

    采用Aspen Adsorption软件对CH4和N2分别为30%和70%低浓度煤层气的吸附过程进行模拟,得到吸附柱出口CH4和N2浓度随时间的变化关系和吸附柱轴向负载分布,考察压力、温度和传质系数对甲烷吸附过程和穿透曲线的影响。研究结果表明:对甲烷出口浓度的模拟值与实验值基本吻合,甲烷在吸附时间3 000 s时达到饱和,吸附量为6.75×10-4kmol/kg,约为氮气吸附量的2倍;甲烷穿透曲线随压力的增大后移,从100~500 kPa的穿透时间从392 s延至2 187 s。温度在273~323 K甲烷的穿透曲线基本不变;传质系数远小于1.000 s-1时对吸附性能影响较大,传质系数为0.001 s-1时的穿透时间约为0.010 s-1时的两倍,但其大于1.000 s-1后对穿透曲线几乎没有影响。%The adsorption process, supported by Aspen Adsorption software, was simulated for low concentration coal- bed methane (CBM) composed of 30% CH4 and 70% N2,and the effects of operating pressure,temperature and the mass transfer coefficient on the outlet methane concentration were studied. Moreover, the variations of the concentra- tions of methane/nitrogen with adsorption time, and the axial distributions of methane/nitrogen adsorption quantity along the adsorption column were obtained. The results show that the simulation values of methane concentration are basically consistent with the results of experiment. The methane is saturated when adsorption time is 3 000 s, with the adsorption quantity of 6. 75 x 10-4 kmol/kg, which is about 2 times larger than that of nitrogen. In addition, the break- through curves of methane shifts to the longer time from 392 s to 2 187 s,with the pressure increasing from 100 kPa to 500 kPa, and the effect of temperature on the breakthrough curve is negligible within the range of 273-323 K. Further- more, the methane adsorption quantity changes evidently when the value of mass transfer coefficient is smaller than 1. 000 s-1 , and the breakthrough

  19. Continuous processing of recombinant proteins: Integration of inclusion body solubilization and refolding using simulated moving bed size exclusion chromatography with buffer recycling.

    Science.gov (United States)

    Wellhoefer, Martin; Sprinzl, Wolfgang; Hahn, Rainer; Jungbauer, Alois

    2013-12-01

    An integrated process which combines continuous inclusion body dissolution with NaOH and continuous matrix-assisted refolding based on closed-loop simulated moving bed size exclusion chromatography was designed and experimentally evaluated at laboratory scale. Inclusion bodies from N(pro) fusion pep6His and N(pro) fusion MCP1 from high cell density fermentation were continuously dissolved with NaOH, filtered and mixed with concentrated refolding buffer prior to refolding by size exclusion chromatography (SEC). This process enabled an isocratic operation of the simulated moving bed (SMB) system with a closed-loop set-up with refolding buffer as the desorbent buffer and buffer recycling by concentrating the raffinate using tangential flow filtration. With this continuous refolding process, we increased the refolding and cleavage yield of both model proteins by 10% compared to batch dilution refolding. Furthermore, more than 99% of the refolding buffer of the raffinate could be recycled which reduced the buffer consumption significantly. Based on the actual refolding data, we compared throughput, productivity, and buffer consumption between two batch dilution refolding processes - one using urea for IB dissolution, the other one using NaOH for IB dissolution - and our continuous refolding process. The higher complexity of the continuous refolding process was rewarded with higher throughput and productivity as well as significantly lower buffer consumption compared to the batch dilution refolding processes.

  20. Process intensification by direct product sequestration from batch fermentations: application of a fluidised bed, multi-bed external loop contactor

    Science.gov (United States)

    Hamilton; Morton; Young; Lyddiatt

    1999-08-01

    A critical comparison has been made of the relative efficacy of the primary purification of an extracellular acid protease produced by the yeast Yarrowia lipolytica. The performance of conventional, discrete sequences of fermentation, broth clarification and fixed bed, anion exchange chromatography has been compared with fluidised bed adsorption directly interfaced with post-term fermentation broth and fluidised bed adsorption directly integrated with productive fermentations (so-called direct product sequestration; DPS). Advantages of the latter, in terms of the improved yield and molecular quality of the protease end product are discussed in terms of the design, assembly and operation of component parts of DPS devices and their generic application to other extracellular bioproducts of microbial fermentations. Copyright 1999 John Wiley & Sons, Inc.

  1. Adsorption and Transfer Properties for Toluene and p-Dichlorobenzene in Dense CO2/Silica Gel Packed Bed System by Moment Method and Time-Domain Analysis

    Institute of Scientific and Technical Information of China (English)

    杨晓宁

    2003-01-01

    Based on chromatographic theory, the moment method and the time-domain fitting analysis were applied to measure and evaluate the adsorption equilibrium constant and mass transfer properties (axial dispersion coefficient and effective intra-particle diffnsivity) for toluene and p-dichlorobenzene on silica gel adsorbent in the subcritical and supercritical CO2. An apparatus based on supercritical fluid chromatography was established and the experiments were performed at temperatures of 298.15-318.15 K and pressures of 7.5-17.8 MPa. The two methods have been compared. The results show that for the systems studied here the moment method can give reasonable values for both adsorption equilibrium constant and mass transfer properties, but the time-domain analysis only can obtain the adsorption equilibrium constant. The dependence of adsorption equilibrium constant and mass transfer properties on temperature and pressure was investigated.

  2. Isolation of potato proteins using simulated moving bed technology.

    Science.gov (United States)

    Andersson, Jonatan; Sahoo, Deepti; Mattiasson, Bo

    2008-12-15

    The simulated moving bed (SMB) concept of chromatography was applied to treat potato juice from production of starch. The aim was to harvest proteins. SMB offers possibilities to operate with different process strategies and in this study it was shown possible to harvest up to 80% of the protein in a process utilizing very little extra water besides that already present in the juice. After depleting protein from the juice in the adsorption step, the flow through was used to recondition the column after elution. The present study illustrates a new concept of applying chromatography as a capturing step of bulk products. PMID:18781695

  3. Adsorption and desorption of noble gases on activated charcoal: I. 133Xe studies in a monolayer and packed bed.

    Science.gov (United States)

    Scarpitta, S C; Harley, N H

    1990-10-01

    Detailed desorption studies using petroleum-based activated charcoals were conducted in monolayers and packed beds. Less extensive studies were conducted on several other types of charcoal. Kinetic studies, using 133Xe, demonstrated the existence of a micropore volume with entrance capillaries that together determined the response characteristics of charcoal to external concentration gradients of tracer gases. This new two-phase model, composed of micropores and entrance capillaries, describes the desorption dynamics of an adsorbed gas in the presence of water vapor. Condensed water vapor in the entrance capillaries of the charcoal reduced the effective pore radius and increased the diffusion half-time. Water could also adversely affect the integrating capability of the charcoal dramatically if the adsorbed water completely blocked the entrance capillaries. The amount of adsorbed water required to block the capillaries varied with the charcoal type and was termed here as the "break-point." The desorption parameters measured in this work can be used to design an improved passive Rn monitor to effectively integrate during a 3-7 d exposure period by eliminating the adverse effects of water vapor. The improved canister design would provide more accurate and reproducible measurements of indoor Rn concentrations than are currently available. PMID:2398007

  4. INVESTIGATION OF HEAT TRANSFER CHARACTER ON ADSORBENT BED WITH CONSIDERATION OF NON-EQUILIBRIUM ADSORPTION%具有非平衡吸附特征的吸附床传热特性研究

    Institute of Scientific and Technical Information of China (English)

    王文; 王如竹

    2001-01-01

    吸附床是固体吸附制冷系统的关键部件,对于连续回热等快速进行的吸附制冷循环,吸附床内温度的变化及其压力交变对吸附特性的影响不可忽视。本文对吸附床在吸附、解吸过程中的温度场和吸附率分布进行了模拟计算,并将其与采用平衡吸附模型的计算结果进行了比较,文中比较及结论有助于深入认识吸附床在制冷循环中工作特性,并为吸附床的设计提供参考依据。%The adsorbent bed is the key element of an adsorption refrigeration system.Its operation characteristics of temperature and pressure affect theadsorption characteristics and cycle performance greatly. The discussions about the temperature and adsorbed mass distribution in the adsorbent bedduring adsorption and desorption processes are shown with numerical method.Both models with equilibrium and non-equilibrium adsorption are compared with each other. It is concluded that non-equilibrium adsorption should beconsidered for solid adsorption refrigeration particularly for short cycletime. The discussion and comparison are helpful to reveal operating performance of adsorbent bed and also to provide reference to the design of adsorbent bed.

  5. Adsorption mechanism in reversed-phase liquid chromatography. Effect of the surface coverage of a monomeric C18-silica stationary phase

    Energy Technology Data Exchange (ETDEWEB)

    Gritti, Fabrice [University of Tennessee, Knoxville (UTK); Guiochon, Georges A [ORNL

    2006-04-01

    The effect of the bonding density of the octadecyl chains onto the same silica on the adsorption and retention properties of low molecular weight compounds (phenol, caffeine, and sodium 2-naphthalene sulfonate) was investigated. The same mobile phase (methanol:water, 20:80, v/v) and temperature (T = 298 K) were applied and two duplicate columns (A and B) from each batch of packing material (neat silica, simply endcapped or C{sub 1} phase, 0.42, 1.01, 2.03, and 3.15 {micro}mol/m{sup 2} of C{sub 18} alkyl chains) were tested. Adsorption data of the three compounds were acquired by frontal analysis (FA) and the adsorption energy distributions (AEDs) were calculated using the expectation-maximization method. Results confirmed earlier findings in linear chromatography of a retention maximum at an intermediate bonding density. From a general point of view, the saturation capacity of the adsorbent tends to decrease with increasing bonding density, due to the vanishing space intercalated between the C{sub 18} bonded chains and to the decrease of the specific surface area of the stationary phase. The equilibrium constants are maximum for an intermediary bonding density ({approx}2 {micro}mol/m{sup 2}). An enthalpy-entropy compensation was found for the thermodynamic parameters of the isotherm data. Weak equilibrium constants (small {Delta}H) and high saturation capacities (large {Delta}S) were observed at low bonding densities, higher equilibrium constants and lower saturation capacities at high bonding densities, the combinations leading to similar apparent retention in RPLC. The use of a low surface coverage column is recommended for preparative purposes.

  6. Multi-objective optimization for the economic production of d-psicose using simulated moving bed chromatography.

    Science.gov (United States)

    Wagner, N; Håkansson, E; Wahler, S; Panke, S; Bechtold, M

    2015-06-12

    The biocatalytic production of rare carbohydrates from available sugar sources rapidly gains interest as a route to acquire industrial amounts of rare sugars for food and fine chemical applications. Here we present a multi-objective optimization procedure for a simulated moving bed (SMB) process for the production of the rare sugar d-psicose from enzymatically produced mixtures with its epimer d-fructose. First, model parameters were determined using the inverse method and experimentally validated on a 2-2-2-2 lab-scale SMB plant. The obtained experimental purities (PUs) were in excellent agreement with the simulated data derived from a transport-dispersive true-moving bed model demonstrating the feasibility of the proposed design. In the second part the performance of the separation was investigated in a multi-objective optimization study addressing the cost-contributing performance parameters productivity (PR) and desorbent requirement (DR) as a function of temperature. While rare sugar SMB operation under conditions of low desorbent consumption was found to be widely unaffected by temperature, SMB operation focusing on increased PR significantly benefited from high temperatures, with possible productivities increasing from 3.4kg(Lday)(-1) at 20°C to 5kg(Lday)(-1) at 70°C, indicating that decreased selectivity at higher temperatures could be fully compensated for by the higher mass transfer rates, as they translate into reduced switch times and hence higher PR. A DR/PR Pareto optimization suggested a similar but even more pronounced trend also under relaxed PU requirements, with the PR increasing from 4.3kg(Lday)(-1) to a maximum of 7.8kg(Lday)(-1) for SMB operation at 50°C when the PU of the non-product stream was reduced from 99.5% to 90%. Based on the in silico optimization results experimental SMB runs were performed yielding considerable PRs of 1.9 (30°C), 2.4 (50°C) and 2.6kg(Lday)(-1) (70°C) with rather low DR (27L per kg of rare sugar produced) on a

  7. A Generalized Adsorption Rate Model Based on the Limiting-Component Constraint in Ion-Exchange Chromatographic Separation for Multicomponent Systems

    DEFF Research Database (Denmark)

    inactive zone) where adsorption/desorption cannot take place because of lack of counterpart species. In packed-bed chromatography described as a distributed dynamic system, a wide range of concentrations including zero-concentrations can be distributed over the column length and the concentration profiles...

  8. Adsorption with biodegradation for decolorization of reactive black 5 by Funalia trogii 200800 on a fly ash-chitosan medium in a fluidized bed bioreactor-kinetic model and reactor performance.

    Science.gov (United States)

    Lin, Yen-Hui; Lin, Wen-Fan; Jhang, Kai-Ning; Lin, Pei-Yu; Lee, Mong-Chuan

    2013-02-01

    A non-steady-state mathematical model system for the kinetics of adsorption and biodegradation of reactive black 5 (RB5) by Funalia trogii (F. trogii) ATCC 200800 biofilm on fly ash-chitosan bead in the fluidized bed process was derived. The mechanisms in the model system included adsorption by fly ash-chitosan beads, biodegradation by F. trogii cells and mass transport diffusion. Batch kinetic tests were independently performed to determine surface diffusivity of RB5, adsorption parameters for RB5 and biokinetic parameters of F. trogii ATCC 200800. A column test was conducted using a continuous-flow fluidized bed reactor with a recycling pump to approximate a completely-mixed flow reactor for model verification. The experimental results indicated that F. trogii biofilm bioregenerated the fly ash-chitosan beads after attached F. trogii has grown significantly. The removal efficiency of RB5 was about 95 % when RB5 concentration in the effluent was approximately 0.34 mg/L at a steady-state condition. The concentration of suspended F. trogii cells reached up to about 1.74 mg/L while the thickness of attached F. trogii cells was estimated to be 80 μm at a steady-state condition by model prediction. The comparisons of experimental data and model prediction show that the model system for adsorption and biodegradation of RB5 can predict the experimental results well. The approaches of experiments and mathematical modeling in this study can be applied to design a full-scale fluidized bed process to treat reactive dye in textile wastewater.

  9. Enrichment of the Glycyrrhizic Acid from Licorice Roots (Glycyrrhiza glabra L. by Isoelectric Focused Adsorptive Bubble Chromatography

    Directory of Open Access Journals (Sweden)

    Eyyüp Karaoğul

    2016-01-01

    Full Text Available The main aim of this study was to enrich glycyrrhizic acid ammonium salt known as one of the main compounds of licorice roots (Glycyrrhiza glabra L. by isoelectric focused adsorptive bubble separation technique with different foaming agents. In the experiments, four bubble separation parameters were used with β-lactoglobulin, albumin bovine, and starch (soluble preferred as foaming agents and without additives. The enrichment of glycyrrhizic acid ammonium salt into the foam was influenced by different additive substances. The results showed that highest enrichment values were obtained from β-lactoglobulin as much as 368.3 times. The lowest enrichment values (5.9 times were determined for the application without additive. After enrichment, each experiment of glycyrrhizic acid ammonium salt confirmed that these substances could be quantitatively enriched into the collection vessel with isoelectric focused adsorptive bubble separation technique. The transfer of glycyrrhizic acid ammonium salt into the foam from standard solution in the presence of additive was more efficient than aqueous licorice extract.

  10. Comparative Analysis and Evaluation on Three Typical Adsorbents for Expanded Bed Adsorption%三种典型扩张床吸附介质的比较分析与评价

    Institute of Scientific and Technical Information of China (English)

    杜巧燕; 林东强; 姚善泾

    2014-01-01

    Expanded bed adsorption (EBA) is a challenge bioseparation approach, which integrates the solid-liquid separation, concentration and primary purification into a unit operation. The key to the EBA is the specially-designed adsorbents. In the present work, the physical and chemical properties of three widely-used EBA adsorbents named Streamline SP, Streamline SP XL and Fastline SP were compared. The expansion characteristic and liquid mixing property of the beds formed by using above three adsorbents separately were compared too. With lactoferrin as the model protein, the adsorption properties including adsorption isotherms, adsorption kinetics and breakthrough curves of the three adsorbents were investigated. The results indicate that the adsorbent with small size can come to adsorption equilibrium faster and the adsorbent with high density could improve the bed stability and allow higher flow rate, which enhances the treating ability of the bed. This work would provide useful information for the design of new EBA adsorbents.%扩张床吸附是一种新型的集固液分离、浓缩、纯化于一体的层析技术,其核心为经过特殊设计的吸附介质。比较了Streamline SP、 Streamline SP XL和 Fastline SP三种常用扩张床介质的理化性质和床层特性,并以乳铁蛋白为模型蛋白,从静态吸附、吸附动力学和动态吸附三方面比较了不同介质的吸附特性。结果表明,介质颗粒小,吸附平衡快;介质密度大,床层稳定性高,适用流速大,过程处理能力高,研究的结果为扩张床吸附介质的理性设计提供指导。

  11. 球形纤维素-钛白粉复合基质的扩张床流体混合特性%Physical and Hydrodynamic Properties of Spherical Cellulose-Titanium Dioxide Composite Matrix for Expanded Bed Adsorption

    Institute of Scientific and Technical Information of China (English)

    雷引林; 林东强; 姚善泾; 刘坐镇; 朱自强

    2003-01-01

    Expanded bed adsorption (EBA) has been widely used in industrial downstream bioprocessing. Solid matrix is the principal pillar supporting the successful application of EBA. A novel spherical cellulose-titanium dioxide composite matrix was prepared through the method of water-in-oil suspension thermal regeneration. Its typical physical properties were wet density 1.18g.cm-3, diameters in the range of 100-300μm, porosity 85.5%,and water content 72.3%. Expansion characteristics and liquid mixing performance of the matrix in expanded bed were investigated using water and 10% (by mass) glycerol solution as mobile phases. The results indicate that the custom-assembled matrix has a stable flow hydrodynamics and exhibits the same degree of liquid-phase mixing or column efficiency as the commercially available Streamline adsorbent.

  12. Optimization of pore structure and particle morphology of mesoporous silica for antibody adsorption for use in affinity chromatography

    Science.gov (United States)

    Hikosaka, Ryouichi; Nagata, Fukue; Tomita, Masahiro; Kato, Katsuya

    2016-10-01

    Antibodies have received significant attention for use as antibody drugs, because they bind the objective protein (antigen) via antigen-antibody reactions. Recently, many reports have appeared on various monoclonal antibodies that recognize a single antigen. In this study, monoclonal antibodies are used as adsorbates on mesoporous silica (MPS) for affinity chromatography. MPS has high surface area and large pore volume; moreover, pore diameter, pore structure, and particle morphology are relatively easy to tune by adjusting the conditions of synthesis. The pore structure (two-dimensional (2D) hexagonal and three-dimensional cubic) and particle morphology (spherical and polyhedral) of MPS are optimized for use in a monoclonal antibody/MPS composite. When anti-IgG (one of the monoclonal antibodies) adsorbs on the MPS material and IgG (antigen) binds to anti-IgG/MPS composites, MCM-41p with a 2D-hexagonal pore structure and polyhedral particle morphology has the highest IgG binding efficiency. In addition, the antibody/MPS composites remain stable in chaotropic and low-pH solutions and can be cycled at least five times without decreasing IgG elution. In purification and removal tests, the use of the antibody/MPS composites allows only the objective protein from protein mixtures to be bound and eluted.

  13. Continuous processing of recombinant proteins: integration of refolding and purification using simulated moving bed size-exclusion chromatography with buffer recycling.

    Science.gov (United States)

    Wellhoefer, Martin; Sprinzl, Wolfgang; Hahn, Rainer; Jungbauer, Alois

    2014-04-11

    Continuous processing of recombinant proteins was accomplished by combining continuous matrix-assisted refolding and purification by tandem simulated moving bed (SMB) size-exclusion chromatography (SEC). Recombinant proteins, N(pro) fusion proteins from inclusion bodies were dissolved with NaOH and refolded in the SMB system with a closed-loop set-up with refolding buffer as the desorbent buffer and buffer recycling of the refolding buffer of the raffinate by tangential flow filtration. For further purification of the refolded proteins, a second SMB operation also based on SEC was added. The whole system could be operated isocratically with refolding buffer as the desorbent buffer, and buffer recycling could also be applied in the purification step. Thus, a significant reduction in buffer consumption was achieved. The system was evaluated with two proteins, the N(pro) fusion pep6His and N(pro) fusion MCP-1. Refolding solution, which contained residual N(pro) fusion peptide, the cleaved autoprotease N(pro), and the cleaved target peptide was used as feed solution. Full separation of the cleaved target peptide from residual proteins was achieved at a purity and recovery in the raffinate and extract, respectively, of approximately 100%. In addition, more than 99% of the refolding buffer of the raffinate was recycled. A comparison of throughput, productivity, and buffer consumption of the integrated continuous process with two batch processes demonstrated that up to 60-fold higher throughput, up to 180-fold higher productivity, and at least 28-fold lower buffer consumption can be obtained by the integrated continuous process, which compensates for the higher complexity.

  14. 等比例变压吸附法富集低浓度煤层气的安全性分析%Safety analysis on low concentration coal bed methane enrichment process by proportion pressure swing adsorption

    Institute of Scientific and Technical Information of China (English)

    李永玲; 刘应书; 杨雄; 郭广栋; 孟宇

    2012-01-01

    在Coward爆炸三角形的基础上分析研究了低浓度煤层气(CH4浓度低于30%)吸附富集过程的安全性。研究结果表明,如果采用常规的变压吸附方法,使用单一吸附剂富集低浓度煤层气,在吸附过程中CH4浓度会进入爆炸极限,存在安全隐患。基于安全性和可行性分析,提出了一种安全的分离富集低浓度煤层气方法——等比例变压吸附法,采用活性炭和碳分子筛作为混合吸附剂,通过调节混合吸附剂中AC/CMS质量比,使低浓度煤层气中甲烷和氧气能按比例同时被吸附,确保整个吸附富集过程中吸附器内、排放气以及解吸气中的甲烷和氧气浓度都处于安全范围内,实现低浓度煤层气的安全有效吸附富集。%The experimental study and safety analysis was carried out on low concentration coal bed methane enrichment based on the coward explosion triangle.The results show that the traditional PSA approach by using single adsorbent will probably make methane concentration very close to the explosion limit and result in explosion risk in the adsorption process,when the methane concentration in coal bed is below 30%.Based on pressure swing adsorption,Proportion Pressure Swing Adsorption(PPSA),a new enrichment method with high safety,was suggested to enrich the low concentration coal bed gas.A mixture of active carbon(AC) and carbon molecular sieve(CMS) was employed as adsorbent in the process of PPSA.The methane and oxygen in coal bed gas were adsorbed simultaneously,where methane was mostly adsorbed on active carbon and oxygen was mostly adsorbed by CMS.The results show that the CH4,O2 concentration can be controlled well and is not over explosive limit both in adsorption and desorption processes by adjusting the mass ratio of CMS5/AC1.

  15. Liquid Chromatography in 1982.

    Science.gov (United States)

    Freeman, David H.

    1982-01-01

    Reviews trends in liquid chromatography including apparatus, factors affecting efficient separation of a mixture (peak sharpness and speed), simplified problem-solving, adsorption, bonded phase chromatography, ion selectivity, and size exclusion. The current trend is to control chemical selectivity by the liquid phase. (Author/JN)

  16. 沁水盆地寺河煤矿煤岩吸附甲烷规律实验研究%Experimental study on methane adsorption of coal bed from Sihe Mine in Qinshui Basin

    Institute of Scientific and Technical Information of China (English)

    张振兵; 邱小龙; 袁月琴; 李向峰; 郝琦; 王军

    2014-01-01

    煤储层具有大量的裂隙和孔隙,使煤岩具有很大的比表面积,为煤中甲烷的吸附提供了必要条件。采用自主研发的煤层气吸附装置,通过对沁水盆地寺河煤矿不同粒径煤粉的吸附性模拟实验,总结了不同粒径煤粉在吸附甲烷12 h内的吸附规律,计算出其中吸附气量,研究了吸附速率、吸附量的变化规律。研究认为:吸附的前10 min,吸附量占总吸附量的40%~60%,煤粉粒径越小,所占的比例越大,吸附越快;不同粒径煤粉的吸附量为15.1~29.1 mL/g,煤粉粒径越小,单位质量煤粉吸附量越大。通过对煤岩吸附规律的深入研究,为沁水盆地煤层气的勘探开发提供技术支持。%Due to abundant racks and pores, coal bed has a huge specific surface area which provides the neces-sary conditions for the adsorption of methane in coal. A case study was made in the Sihe Mine in the Qinshui Ba-sin. Using the self-developed CBM adsorption experiment instrument, the absorption rules ( including rate and amount) within 12 h of methane in coal of different sizes were studied. The absorption amount during the prior 10 minutes accounts for 40%-60% of total absorption amount. Moreover, the smaller the coal particle is, the bigger proportion the small particle accounts for, the faster the methane is absorbed. The adsorption capacities for differ-ent coal sizes range from 15.1 to 33.6 mL/g. The smaller the coal particle is, the more methane is absorbed in coal per unit. The study of the adsorption law of coal bed provides technological supports for the exploration and development of the Qinshui Basin.

  17. Experiment study on process parameters of coal-bed gas separation by vacuum pressure swing adsorption%真空变压吸附分离含氧煤层气的工艺参数实验研究

    Institute of Scientific and Technical Information of China (English)

    刘应书; 杨雄; 李永玲; 张传钊; 孟宇; 杨海军

    2011-01-01

    Oxygen-containing coal-bed gas recovery using vacuum pressure swing adsorption processes is investigated expenmentally, the optimization experiment on process parameters and the structure of adsorption tower is camed out. The results show that the methane concentration in effluent gas and adsorption gas increases with the increase of adsorption time within a certain time, but the oxygen concentration in effluent gas decreases appreciably. Purge step decreases the methane and oxygen concentration of the effluent gas, but the methane concentration of desorption gas decreases with the increase of purge time. When the length-to-diameter ratio from 3.7 increased to 13. 3 with the adsorhent weight constant , the methane concentration in product increases by 2. 1 % , and the concentration of methane in effluent gas decreases by 1%. The results could provide reference for the industrial application in low concentration oxygen-containing coal-bed gas enrichment.%针对真空变压吸附富集低浓度含氧煤层气,对工艺参数和吸附塔结构进行了优化试验研究.实验结果标明,在一定的时间范围内,随着吸附时间的延长,解吸气和排放气中甲烷体积分数逐渐增大,而排放气中的氧气体积分数则小幅度降低;反吹步骤可以降低排放气中甲烷和氧气的体积分数,但反吹步骤也会降低解吸气中甲烷的体积分数;保持吸附剂不变,吸附塔高径比由3.7增大到13.3,解吸气中甲烷体积分数增大了2.1%,排放气中甲烷体积分数降低了1%.可以为低浓度含氧煤层气富集的实际应用提供参考.

  18. 沸石ZSM-5吸附回收低浓度煤层气中CH4%Adsorption and recovery of low concentration coal-bed methane by zeolite ZSM-5

    Institute of Scientific and Technical Information of China (English)

    刘海庆; 吴一江; 杨颖; 杨林; 李平; 于建国

    2016-01-01

    As a high-silica hydrophobic material, zeolite ZSM-5 was used for the adsorption and recovery of low concentration coal-bed methane. Theoretical and experimental studies were conducted on adsorption equilibrium, adsorption kinetics and vacuum pressure swing adsorption (VPSA). Single and binary competitive adsorption equilibrium experimental data of CH4/N2 on zeolite ZSM-5 were measured by gravimetric method and breakthrough-curve method. The multi-site Langmuir model was used to fit the experimental data. Microporous diffusion coefficients were calculated based on the experimental data of diluted breakthrough curves and simulated results of an isothermic mathematical bi-disperse model without momentum loss. Competitive breakthrough curves of CH4and N2 on zeolite ZSM-5 were predicted by fixed bed adsorption models with mass, momentum and energy transfer. Effects of CH4 concentration in feed, feed flow rate, feed time and purge/feed flow rate ratio on separation performances of ZSM-5 packed single column four-step VPSA process were investigated. It showed that ZSM-5 zeolite exhibited a relatively good selectivity for CH4 and the diffusion in micropores was the ratedetermining step for both CH4 and N2 adsorption. By the process of VPSA, CH4 purity can be concentrated from 20% to 31%~41% and the recovery can be up to 93%~98%.%利用高硅疏水性沸石ZSM-5吸附回收低浓度煤层气中的甲烷,对其吸附平衡、吸附动力学以及真空变压吸附分离过程进行了理论和实验研究.通过重量法和穿透曲线法测定了CH4/N2单组分及双组分的竞争吸附平衡数据,并采用Multisite Langmuir吸附等温线模型对其进行拟合.结合CH4和N2稀释穿透曲线实验数据和等温无动量损失的双分散二级孔结构扩散模型,获得CH4和N2在沸石ZSM-5上的微孔扩散系数.建立并求解包含质量、动量及能量传递的固定床吸附分离模型方程,预测了CH4和N2在沸石ZSM-5上的竞争吸附

  19. Hydrogen purification by multi-bed pressure swing adsorption technology and its optimization%复合床变压吸附制氢工艺试验与优化

    Institute of Scientific and Technical Information of China (English)

    刘吉顺; 李可彬

    2016-01-01

    以活性炭和5A分子筛为吸附剂,H2、CO、CO23组分混合为气源,建立了5-1-3P的五塔复合床试验,就变压吸附工艺参数对制氢效果的影响进行了研究.先后进行了单因素试验和响应试验,分析了吸附压力,吸附时间和进料量对H2的体积分数和回收率的影响,并利用响应曲面法对制氢工艺参数进行了分析和优化.结果表明,对氢气的体积分数影响显著关系为吸附压力>进料量>吸附时间,当吸附压力0.85 MPa,吸附时间80 s,进料量14.5 L/min,氢气体积分数可达99.987%,收率为73.52%,与预测值相对误差很小,说明回归的二次多项方程模型能够较真实地反映试验结果,可用于复合床变压吸附制氢工艺条件的分析和预测.%A five-tower multilayer bed test 5-1-3P is established with activated carbon and 5A molecular sieve as adsorbent,the mixture of H2,CO and CO2 as a three-component gas source.The influence of pressure swing adsorption (PSA) process parameters on the hydrogen production is studied by single factor test and response test.The effects of adsorption pressure,adsorption time and feed rate on the purity (vol) and recovery of H2 are analyzed.Response surface methodology is used to analyze and optimize the process parameters.Th results show that the purity (vol) of hydrogen is greatly related to the adsorption pressure,the adsorption time and feed rate in a descending order.The purity (vol) and yield of hydrogen are 99.987% and 73.52% respectively,under the following conditions:0.85 MPa of adsorption pressure,80 s of adsorption time and 14.5 L/min of feed rate.Moreover,the relative error between the test value and the forecast value is very small It indicates that the quadratic regression equation model can be used to truly reflect the test results and to analyze and forecast the process conditions of PSA hydrogen production by compound bed.

  20. Regenerative adsorption distillation system

    KAUST Repository

    Ng, Kim Choon

    2013-12-26

    There is provided a regenerative adsorption distillation system comprising a train of distillation effects in fluid communication with each other. The train of distillation effects comprises at least one intermediate effect between the first and last distillation effects of the train, each effect comprising a vessel and a condensing tube for flow of a fluid therein. The system further comprises a pair of adsorption-desorption beds in vapour communication with the last effect and at least one intermediate effect, wherein the beds contain an adsorbent that adsorbs vapour from the last effect and transmits desorbed vapour into at least one of the intermediate effect.

  1. Determination of a wide range of volatile organic compounds in ambient air using multisorbent adsorption/thermal desorption and gas chromatography/mass spectrometry

    Science.gov (United States)

    Pankow, J.F.; Luo, W.; Isabelle, L.M.; Bender, D.A.; Baker, R.J.

    1998-01-01

    Adsorption/thermal desorption with multisorbent air-sampling cartridges was developed for the determination of 87 method analytes including halogenated alkanes, halogenated alkenes, ethers, alcohols, nitriles, esters, ketones, aromatics, a disulfide, and a furan. The volatilities of the compounds ranged from that of dichlorofluoromethane (CFC12) to that of 1,2,3- trichlorobenzene. The eight most volatile compounds were determined using a 1.5-L air sample and a sample cartridge containing 50 mg of Carbotrap B and 280 mg of Carboxen 1000; the remaining 79 compounds were determined using a 5-L air sample and a cartridge containing 180 mg of Carbotrap B and 70 mg of Carboxen 1000. Analysis and detection were by gas chromatography/mass spectrometry. The minimum detectable level (MDL) concentration values ranged from 0.01 parts per billion by volume (ppbv) for chlorobenzene to 0.4 ppbv for bromomethane; most of the MDL values were in the range 0.02-0.06 ppbv. No breakthrough was detected with the prescribed sample volumes. Analyte stability on the cartridges was very good. Excellent recoveries were obtained with independent check standards. Travel spike recoveries ranged from 90 to 110% for 72 of the 87 compounds. The recoveries were less than 70% for bromomethane and chloroethene and for a few compounds such as methyl acetate that are subject to losses by hydrolysis; the lowest travel spike recovery was obtained for bromomethane (62%). Blank values for all compounds were either below detection or very low. Ambient atmospheric sampling was conducted in New Jersey from April to December, 1997. Three sites characterized by low, moderate, and high densities of urbanization/traffic were sampled. The median detected concentrations of the compounds were either similar at all three sites (as with the chlorofluorocarbon compounds) or increased with the density of urbanization/traffic (as with dichloromethane, MTBE, benzene, and toluene). For toluene, the median detected

  2. Comparison for CO Preparation by Oxygen Surplus Gasification Method in Fixed Bed with Using Pressure Variation Adsorption Method%固定床富氧造气法与变压吸附法制备 CO 的比较

    Institute of Scientific and Technical Information of China (English)

    张雷; 陆丽萍

    2013-01-01

    分别介绍了固定床富氧造气法与变压吸附法制备CO的工艺原理和工艺流程;从装置投资、生产操作、运行成本等方面对比了2种制备方法的优点和缺点。%Author has separately introduced the process principle and process flow for preparing CO by oxygen surplus gasification method in fixed bed and by pressure variation adsorption method; has compared the advantages and shortages of two kinds of preparing methods from aspects of investment of device, productive operation, operating cost etc.

  3. Studies Regarding As(V Adsorption from Underground Water by Fe-XAD8-DEHPA Impregnated Resin. Equilibrium Sorption and Fixed-Bed Column Tests

    Directory of Open Access Journals (Sweden)

    Mihaela Ciopec

    2014-10-01

    Full Text Available The characteristics of arsenic adsorption onto Fe-XAD8-DEHPA resin were studied on the laboratory scale using aqueous solutions and natural underground waters. Amberlite XAD8 resin was impregnated with di(2-ethylhexyl phosphoric acid (DEHPA via the dry method of impregnation. Fe(III ions were loaded onto the impregnated resin by exploiting the high affinity of arsenic towards iron. The studies were conducted by both in contact and continuous modes. Kinetics data revealed that the removal of arsenic by Fe-XAD8-DEHPA resin is a pseudo-second-order reaction. The equilibrium data were modelled with Freundlich Langmuir and Dubinin Radushkevich (D-R isotherms and it was found that the Freundlich model give the poorest correlation coefficient. The maximum adsorption capacity obtained from the Langmuir isotherm is 22.6 µg As(V/g of Fe-XAD8-DEHPA resin. The mean free energy of adsorption was found in this study to be 7.2 kJ/mol and the ΔG° value negative (−9.2 kJ/mol. This indicates that the sorption process is exothermal, spontaneous and physical in nature. The studied Fe-XAD8-DEHPA resin showed excellent arsenic removal performance by sorption, both from synthetic solution and the natural water sample, and could be regenerated simply by using aqueous NaOH or HCl solutions.

  4. BATCH AND FIXED BED ADSORPTION STUDIES OF LEAD (II CATIONS FROM AQUEOUS SOLUTIONS ONTO GRANULAR ACTIVATED CARBON DERIVED FROM MANGOSTANA GARCINIA SHELL

    Directory of Open Access Journals (Sweden)

    Zaira Zaman Chowdhury,

    2012-05-01

    Full Text Available The feasibility of granular activated carbon (GAC derived from Mangostene (Mangostana garcinia fruit shell to remove lead, Pb2+ cations was investigated in batch and fixed bed sorption systems. Batch experiments were carried out to study equilibrium isotherms, kinetics, and thermodynamics by using an initial lead (Pb2+ ions concentration of 50 to 100 mg/L at pH 5.5. Equilibrium data were fitted using Langmuir, Freundlich, and Temkin linear equation models at temperatures 30°C, 50°C, and 70°C. Langmuir maximum monolayer sorption capacity was 25.00 mg/g at 30°C. The experimental data were best represented by pseudo-second-order and Elovich models. The sorption process was found to be feasible, endothermic, and spontaneous. In column experiments, the effects of initial cation concentration (50 mg/L, 70 mg/L, and 100 mg/L, bed height (4.5 cm and 3 cm, and flow rate (1 mL/min and 3 mL/min on the breakthrough characteristics were evaluated. Breakthrough curves were further analyzed by using Thomas and Yoon Nelson models to study column dynamics. The column was regenerated and reused consecutively for four cycles. The result demonstrated that the prepared activated carbon was suitable for removal of Pb2+ from synthetic aqueous solution using batch, as well as fixed bed sorption systems.

  5. Adsorption design for wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Cooney, D.O.

    1998-12-31

    Understand the premier method for removing organic contaminants from water. Straight forward explanations and illustrations allow this overview to fill a dual purpose: study manual and design guide. The book discusses basic properties of activated carbons; explains the kinetics of adsorption processes; describes the design of both fixed-bed and batch process adsorption systems; contains useful knowledge that can be extended to other applications of adsorption, including drinking water treatment; and includes many illustrated examples and practice exercises.

  6. 采用复合吸附剂和高效吸附床的吸附制冷机性能测试%Performance test of adsorption chiller employed composite adsorbents and efficient adsorption bed

    Institute of Scientific and Technical Information of China (English)

    王令宝; 卜宪标; 马伟斌

    2012-01-01

    This paper developed a small adsorption chiller employed parallel flow heat exchanger and self-made silica gel/calcium chloride composite adsorbents, and the chiller performance has been tested. The testing results indicate that the COP and the cooling power of the composite adsorption chiller are significantly improved compared with silica gel adsorption chiller. The performance testing of ad-sorption chiller shows that the cooling capacity, SCP and COP is 1.03 kW, 128.3 W/kg and 0.29, respectively, when hot water temperature, cooling water temperature, chilled water inlet temperature, chilled water outlet temperature and circulation time is 90,35,16.5,14.4 t and 15 min. The cooling power and the SCP is 1.54 kW and 192.4 W/kg, when hot water temperature,cooling water temperature,chilled water inlet temperature, chilled water outlet temperature and circulation time is 90 ,35 ,16.5 ,14.4 °C and 15 min. The energy density of the prototype is 10.3 kW/m3. The coefficient of heat transfer of the parallel flow heat exchanger is 472.3 W/(m2-K).%利用平行流换热器和自制的硅胶/氯化钙复合吸附剂研制了一台小型吸附式制冷样机,并对样机进行 了试验测试.测试结果表明:相对于硅胶吸附制冷样机,复合吸附剂吸附制冷样机的COP和制冷功率都有了明显的提高;在热源温度为90℃,冷却水温度为35℃,冷冻水进口温度为16.5℃、出口温度为14.4℃,吸附10min,脱附5 min的运行工况下,在整个循环周期内(15 min),制冷功率为1.03 kW,SCP为128.3 W/kg,COP为0.29;在吸附周期内(10 min),制冷功率为1.54 kW,SCP为192.4 W/kg,样机的能量密度为10.3 kW/m3,平行流换热器的换热系数为472.3 W/(m2·K).

  7. Experimental and Numerical Investigation of Two Dimensional CO2 Adsorption/Desorption in Packed Sorption Beds under Non-Ideal Flows

    Science.gov (United States)

    Mohamadinejad, H.; Knox, J. C.; Smith, J. E.; Croomes, Scott (Technical Monitor)

    2001-01-01

    The experimental results of CO2 adsorption and desorption in a packed column indicated that the concentration wave front at the center of the packed column differs from those which are close to the wall of column filled with adsorbent material even though the ratio of column diameter to the particle size is greater than 20. The comparison of the experimental results with one dimensional model of packed column shows that in order to simulate the average breakthrough in a packed column a two dimensional (radial and axial) model of packed column is needed. In this paper the mathematical model of a non-slip flow through a packed column with 2 inches in diameter and 18 inches in length filled with 5A zeolite pellets is presented. The comparison of experimental results of CO2 absorption and desorption for the mixed and central breakthrough of the packed column with numerical results is also presented.

  8. in Spouted Bed

    Directory of Open Access Journals (Sweden)

    Bronislaw Buczek

    2013-01-01

    Full Text Available Samples of active coke, fresh and spent after cleaning flue gases from communal waste incinerators, were investigated. The outer layers of both coke particles were separately removed by comminution in a spouted bed. The samples of both active cokes were analysed by means of densities, mercury porosimetry, and adsorption technique. Remaining cores were examined to determine the degree of consumption of coke by the sorption of hazardous emissions (SO2, HCl, and heavy metals through its bed. Differences in contamination levels within the porous structure of the particles were estimated. The study demonstrated the effectiveness of commercial active coke in the cleaning of flue gases.

  9. Simulated moving bed system for CO.sub.2 separation, and method of same

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Jeannine Elizabeth; Copeland, Robert James; Lind, Jeff; Leta, Daniel P.; McCall, Patrick P.

    2016-09-20

    A system and method for separating and/or purification of CO.sub.2 gas from a CO.sub.2 feed stream is described. The system and method include a plurality of fixed sorbent beds, adsorption zones and desorption zones, where the sorbent beds are connected via valve and lines to create a simulated moving bed system, where the sorbent beds move from one adsorption position to another adsorption position, and then into one regeneration position to another regeneration position, and optionally back to an adsorption position. The system and method operate by concentration swing adsorption/desorption and by adsorptive/desorptive displacement.

  10. ADSORPTION BEHAVIOUR OF n-PARAFFINS CONTAINED IN NAPHTHA ON THE BED WITH BINDERLESS 5A MOLECULAR SIEVE%石脑油中正构烷烃在无黏结剂5A分子筛床层中的吸附行为研究

    Institute of Scientific and Technical Information of China (English)

    孙辉; 沈本贤; 焦鑫

    2011-01-01

    在固定床吸附分离实验装置上对比研究石脑油中正构烷烃在无黏结剂和有黏结剂5A分子筛床层中的吸附行为.结果表明,随着碳数的增加,各正构烷烃穿透床层的时间增加.与有黏结剂5A分子筛床层相比,无黏结剂5A分子筛床层具有更高的正构烷烃吸附容量,床层穿透时的油筛比(原料油与分子筛质量比)更大.在吸附温度300℃、石脑油进料空速90 h-1的条件下,无黏结剂5A分子筛对石脑油中正构烷烃的动态吸附容量较有黏结剂5A分子筛高34.5%.正构烷烃在无黏结剂5A分子筛床层中的传质段长度小于有黏结剂5A分子筛床层,无黏结剂5A分子筛床层的有效利用率更高.%Adsorption of n-paraffins contained in naphtha on 5A molecular sieve pellets with/without binder was studied on a fixed bed adsorption device. The results indicated that the adsorption breakthrough times of various n-paraffins increased with the increase of n-paraffins' carbon number. As compared with molecular sieve with binder, the adsorption bed of binderless 5A molecular sieve showed higher adsorption capacities for n-paraffins; at an adsorption temperature of 300 ℃ and a space velocity of 90 h-1, the dynamic adsorption capacity of binderless 5A molecular sieve was 34.5 % higher than that of molecular sieve with binder,which indicated that more naphtha feed could be processed or less molecular sieve pellets should be packed. Furthermore,the mass-transfer zone of bed with binderless 5A molecular sieve was shorter, which suggested that the effective using rate of this adsorption bed was higher.

  11. The Calculation of Adsorption Isotherms from Chromatographic Peak Shapes

    Science.gov (United States)

    Neumann, M. G.

    1976-01-01

    Discusses the relationship between adsorption isotherms and elution peak shapes in gas chromatography, and describes a laboratory experiment which involves the adsorption of hexane, cyclohexane, and benzene on alumina at different temperatures. (MLH)

  12. Determination of metals in soils and sewage sludges by ion chromatography and the effect of cropping systems on metal adsorption by soils

    Energy Technology Data Exchange (ETDEWEB)

    Basta, N.T.

    1989-01-01

    An accurate and precise ion chromatographic (IC) method for determination of total Cu, Ni, and Zn in soils was developed. The metals in soil digests were extracted with dithizone in CHCl{sub 3}, and the metal-dithizonate complexes were digested with HNO{sub 3} before injection into the IC system. After separation on HPIC-CS5 column, the metals were determined by measuring the absorbance of metal complexes formed by postcolumn reaction with 4-(2-pyridylazo) resorcinol (PAR) at 520 nm. The results by this IC method agreed closely with those obtained by atomic absorption spectrophotometry (AA). Comparison of results of total Cu, Mn, Ni, Pb, and Zn with those obtained by AA showed that this method was accurate and precise for determination of metals in sewage sludges. The effect of cropping systems on adsorption of metals by soils was studied for two long-term rotation experiments, each having three crop rotations (continuous corn (CCCC), corn-soybean-corn-soybean, and corn-oats-meadow-meadow) and treatments with (+N) and without (O N) ammoniacal fertilizer. Results for soils under CCC rotations (+N) showed lower metal adsorption than those under CCCC (O N) and other crop rotations, which showed similar metal adsorption. Comparison of results obtained after adjusting the soil-solution pH with those for unadjusted solution pH showed that differences in metal adsorption by these soils were due to solution pH. Plots of the logarithm of the metal distribution coefficient (log K{sub d}) vs. pH suggested competition of protons with metal ions for exchange sites. In general, proton coefficient values (H{sup +}/M{sup 2+} ratios) followed the sequence: Pb > Cu > Cd = Ni = Zn. Calculated H{sup +}/M{sup 2+} ratios of <2 (ranging from 0.288 to 1.45) were obtained.

  13. 固定床双塔并联吸附分离石脑油中正构烷烃%ADSORPTION OF NORMAL PARAFFINS FROM NAPHTHA USING 5A MOLECULAR SIEVES IN A DOUBLE-COLUMN FIXED-BED

    Institute of Scientific and Technical Information of China (English)

    曹昕; 刘纪昌; 沈本贤; 孙辉

    2013-01-01

    In order to make a better use of different components in naphtha to produce ethylene and aromatics based on the strategy of molecular scale management, studies on the adsorption separation of normal paraffins from naphtha using 5A molecular sieve in a double-column fixed-bed were carried out. After 5 adsorption/desorption circles, the adsorption separation process reached dynamic balance. The optimal conditions for the adsorption/desorption process are an operation temperature of 270 ℃, a naphtha feed space velocity of 153. 4 h-1 , a switch time of 30 minutes, an intermediate oil cutting time of 2 minutes and N2 flow rate of 127. 5 h-1. The normal paraffin content in the raffinate oil is less than 3% and the potential aromatic content of the raffinate oil is 10% higher than that of the SGPC naphtha. The normal paraffin content in desorption oil is over 95%. The ethylene yield is improved by 13% - 14% using the desorption oil as stream cracking feed compared to the naphtha feed.%在固定床单柱吸附分离研究的基础上,通过程序控制的5A分子筛固定床双塔并联吸附分离试验装置,对中国石化上海高桥分公司石脑油中正构烷烃吸附/脱附分离过程进行连续操作,考察了多周期运转的吸附分离效果,并对工艺条件进行考察.研究结果表明,吸余油中正构烷烃含量经过5个吸附/脱附周期后趋于稳定,优化的吸附分离操作条件为:石脑油原料体积空速153.4 h-1,吸附/脱附温度270℃,吸附/脱附切换时间30 min,脱附气体体积空速127.5 h-1,中间油切割时间2 min.在该工艺条件下,稳定操作的吸余油中正构烷烃质量分数小于3%,芳烃潜含量比石脑油提高12.31百分点;脱附油中正构烷烃质量分数大于95%,作蒸汽裂解制乙烯原料时,与石脑油相比,乙烯收率提高约14百分点.

  14. Identification of chemical warfare agents from vapor samples using a field-portable capillary gas chromatography/membrane-interfaced electron ionization quadrupole mass spectrometry instrument with Tri-Bed concentrator.

    Science.gov (United States)

    Nagashima, Hisayuki; Kondo, Tomohide; Nagoya, Tomoki; Ikeda, Toru; Kurimata, Naoko; Unoke, Shohei; Seto, Yasuo

    2015-08-01

    A field-portable gas chromatograph-mass spectrometer (Hapsite ER system) was evaluated for the detection of chemical warfare agents (CWAs) in the vapor phase. The system consisted of Tri-Bed concentrator gas sampler (trapping time: 3s(-1)min), a nonpolar low thermal-mass capillary gas chromatography column capable of raising temperatures up to 200°C, a hydrophobic membrane-interfaced electron ionization quadrupole mass spectrometer evacuated by a non-evaporative getter pump for data acquisition, and a personal computer for data analysis. Sample vapors containing as little as 22μg sarin (GB), 100μg soman (GD), 210μg tabun (GA), 55μg cyclohexylsarin (GF), 4.8μg sulfur mustard, 390μg nitrogen mustard 1, 140μg of nitrogen mustard 2, 130μg nitrogen mustard 3, 120μg of 2-chloroacetophenone and 990μg of chloropicrin per cubic meter could be confirmed after Tri-Bed micro-concentration (for 1min) and automated AMDIS search within 12min. Using manual deconvolution by background subtraction of neighboring regions on the extracted ion chromatograms, the above-mentioned CWAs could be confirmed at lower concentration levels. The memory effects were also examined and we found that blister agents showed significantly more carry-over than nerve agents. Gasoline vapor was found to interfere with the detection of GB and GD, raising the concentration limits for confirmation in the presence of gasoline by both AMDIS search and manual deconvolution; however, GA and GF were not subject to interference by gasoline. Lewisite 1, and o-chlorobenzylidene malononitrile could also be confirmed by gas chromatography, but it was hard to quantify them. Vapors of phosgene, chlorine, and cyanogen chloride could be confirmed by direct mass spectrometric detection at concentration levels higher than 2, 140, and 10mg/m(3) respectively, by bypassing the micro-concentration trap and gas chromatographic separation. PMID:26118803

  15. Continuous recovery of valine in a model mixture of amino acids and salt from Corynebacterium bacteria fermentation using a simulated moving bed chromatography.

    Science.gov (United States)

    Park, Chanhun; Nam, Hee-Geun; Jo, Se-Hee; Wang, Nien-Hwa Linda; Mun, Sungyong

    2016-02-26

    The economical efficiency of valine production in related industries is largely affected by the performance of a valine separation process, in which valine is to be separated from leucine, alanine, and ammonium sulfate. Such separation is currently handled by a batch-mode hybrid process based on ion-exchange and crystallization schemes. To make a substantial improvement in the economical efficiency of an industrial valine production, such a batch-mode process based on two different separation schemes needs to be converted into a continuous-mode separation process based on a single separation scheme. To address this issue, a simulated moving bed (SMB) technology was applied in this study to the development of a continuous-mode valine-separation chromatographic process with uniformity in adsorbent and liquid phases. It was first found that a Chromalite-PCG600C resin could be eligible for the adsorbent of such process, particularly in an industrial scale. The intrinsic parameters of each component on the Chromalite-PCG600C adsorbent were determined and then utilized in selecting a proper set of configurations for SMB units, columns, and ports, under which the SMB operating parameters were optimized with a genetic algorithm. Finally, the optimized SMB based on the selected configurations was tested experimentally, which confirmed its effectiveness in continuous separation of valine from leucine, alanine, ammonium sulfate with high purity, high yield, high throughput, and high valine product concentration. It is thus expected that the developed SMB process in this study will be able to serve as one of the trustworthy ways of improving the economical efficiency of an industrial valine production process.

  16. Fibronectin purification from human plasma in a packed-bed column system with gelatin immobilized PHEMA microspheres.

    Science.gov (United States)

    Kayirhan-Denizli, F; Arica, M Y; Denizli, A

    2001-01-01

    Bioaffinity chromatography has a unique and powerful role that is used as a purification tool in the production of therapeutic plasma protein derivatives. In this study, a bioaffinity-ligand, i.e. gelatin, was covalently immobilized with PHEMA microspheres (150-200 microm in diameter). The affinity sorbent carrying 7.5 mg gelatin g(-1) polymer was then used to separate fibronectin from human plasma in a packed-bed column system. Fibronectin separation from human plasma on unmodified PHEMA microspheres was 0.45 mg g(-1), while much higher adsorption values, up to 21.8 mg g(-1), were obtained with gelatin-immobilized microspheres. The fibronectin adsorption capacity of the microspheres decreased with an increase in the recirculation rate of plasma. Fibronectin adsorption increased with decreasing temperature, and the maximum adsorption achieved at 4 degrees C (26.3 mg fibronectin g(-1)). Up to 94.7% of the adsorbed fibronectin was desorbed by using 2 M urea in the presence of 1 M sodium chloride as elution agent. The adsorption-desorption cycle was repeated ten times using the same affinity column. There was no remarkable reduction in the adsorption capacity of the gelatin-immobilized PHEMA microspheres. PMID:11469779

  17. Studies with an immobilized metal affinity chromatography cassette system involving binuclear triazacyclononane-derived ligands: automation of batch adsorption measurements with tagged recombinant proteins.

    Science.gov (United States)

    Petzold, Martin; Coghlan, Campbell J; Hearn, Milton T W

    2014-07-18

    This study describes the determination of the adsorption isotherms and binding kinetics of tagged recombinant proteins using a recently developed IMAC cassette system and employing automated robotic liquid handling procedures for IMAC resin screening. These results confirm that these new IMAC resins, generated from a variety of different metal-charged binuclear 1,4,7-triaza-cyclononane (tacn) ligands, interact with recombinant proteins containing a novel N-terminal metal binding tag, NT1A, with static binding capacities similar to those obtained with conventional hexa-His tagged proteins, but with significantly increased association constants. In addition, higher kinetic binding rates were observed with these new IMAC systems, an attribute that can be positively exploited to increase process productivity. The results from this investigation demonstrate that enhancements in binding capacities and affinities were achieved with these new IMAC resins and chosen NT1A tagged protein. Further, differences in the binding performances of the bis(tacn) xylenyl-bridged ligands were consistent with the distance between the metal binding centres of the two tacn moieties, the flexibility of the ligand and the potential contribution from the aromatic ring of the xylenyl group to undergo π/π stacking interactions with the tagged proteins.

  18. Determination of active carbon adsorption gas chromatography of Nonanol%活性炭吸附-气相色谱法测定大气中的壬醇

    Institute of Scientific and Technical Information of China (English)

    王彤梅; 王瑞

    2013-01-01

    The establishment of activated carbon adsorption in ambient air of nonyl alcohol , carbon disulfide desorption , using DB-624 capillary column separation , hydrogen flame ionization detector , time is qualitative , quantitative peak area .Nonyl alcohol recovery rate was 95.5% ~between 103.1%, when the sampling volume 20L, minimum detectable concentration of alcohol for 0.006mg/m3 .This method is easy pretreatment , separation of good , high analysis sensitivity , and can meet the demands of environmental analysis .%建立了活性炭吸附环境空气中壬醇,二硫化碳解吸,用DB-624毛细管柱分离,氢火焰离子化检测器检测,时间定性,峰面积定量。壬醇回收率在95.5%~103.1%之间,当采样体积为20L,壬醇最低检出质量浓度均为0.006mg/m3。本方法前处理简便,分离度好,分析灵敏度高,能满足环境分析要求。

  19. Thin-Layer Chromatography Experiments That Illustrate General Problems in Chromatography.

    Science.gov (United States)

    Lederer, M.; Leipzig-Pagani, E.

    1996-01-01

    Describes experiments that illustrate a number of general principles such as pattern identification, displacement chromatography, and salting-out adsorption, plus an experiment that demonstrates that identification by chromatography alone is impossible. Illustrates that chromatography is still possible with quite simple means, notwithstanding the…

  20. Fractionation of Plant Bioactives from Black Carrots (Daucus carota subspecies sativus varietas atrorubens Alef.) by Adsorptive Membrane Chromatography and Analysis of Their Potential Anti-Diabetic Activity.

    Science.gov (United States)

    Esatbeyoglu, Tuba; Rodríguez-Werner, Miriam; Schlösser, Anke; Liehr, Martin; Ipharraguerre, Ignacio; Winterhalter, Peter; Rimbach, Gerald

    2016-07-27

    Black and purple carrots have attracted interest as colored extracts for coloring food due to their high content of anthocyanins. This study aimed to investigate the polyphenol composition of black carrots. Particularly, the identification and quantification of phenolic compounds of the variety Deep Purple carrot (DPC), which presents a very dark color, was performed by HPLC-PDA and HPLC-ESI-MS(n) analyses. The separation of polyphenols from a DPC XAD-7 extract into an anthocyanin fraction (AF) and co-pigment fraction (CF; primarily phenolic acids) was carried out by membrane chromatography. Furthermore, possible anti-diabetic effects of the DPC XAD-7 extract and its AF and CF were determined. DPC samples (XAD-7, CF, and AF) inhibited α-amylase and α-glucosidase in a dose-dependent manner. Moreover, DPC XAD-7 and chlorogenic acid, but not DPC CF and DPC AF, caused a moderate inhibition of intestinal glucose uptake in Caco-2 cells. However, DPC samples did not affect glucagon-like peptide-1 (GLP-1) secretion and dipeptidyl peptidase IV (DPP-4) activity. Overall, DPC exhibits an inhibitory effect on α-amylase and α-glucosidase activity and on cellular glucose uptake indicating potential anti-diabetic properties. PMID:27362825

  1. ADSORPTION OF GOLD ON TBP EXTRACTING RESIN FROM HCl SOLUTION

    Institute of Scientific and Technical Information of China (English)

    GaoHaoqi; CaoZhikai; 等

    1998-01-01

    Adsorption of gold on TBP extracting resin from HCl solution was researched.All the effects of factors,such as solution acidity,TBP content,temperature,etc.,on adsorption equilibrium were discussed and the equilibrium equation was formulated.The breakthough time of adsorption process with fixed bed was studied through experiment.

  2. Hydrophobic interaction ligand selection and scale-up of an expanded bed separation of an intracellular enzyme from Saccharomyces cerevisiae.

    Science.gov (United States)

    Smith, M P; Bulmer, M A; Hjorth, R; Titchener-Hooker, N J

    2002-08-30

    A prototype Streamline-Phenyl matrix was evaluated in a hydrophobic interaction mode for the direct recovery of alcohol dehydrogenase (ADH) from yeast cell homogenate. At 5% breakthrough of ADH, a yield of 100% was obtained for a dynamic expanded bed capacity of 240 U(ADH)/ml matrix with a purification factor of 9.2. This compared with a dynamic capacity of 3013 U(ADH)/ml matrix for the packed bed equivalent and a purification factor of 18. In both systems the purification factor was found to increase simultaneously with a decrease in yield as the load of homogenate or breakthrough of ADH was increased. The expanded bed mode of operation conferred considerable robustness with respect to process fouling. No loss in yield was seen over five cycles of repeat loading with an unclarified homogenate. By contrast the packed bed media showed a decrease in yield from 86 to 56% over the same period. Successful scale up of the expanded bed protocol for a 20% breakthrough was demonstrated over a fourfold increase in column diameter. The application of hydrophobic interaction chromatography mediated expanded bed adsorption and its scale-up is discussed in the context of large-scale operations.

  3. Multiresidue analysis of 88 polar organic micropollutants in ground, surface and wastewater using online mixed-bed multilayer solid-phase extraction coupled to high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Huntscha, Sebastian; Singer, Heinz P; McArdell, Christa S; Frank, Carolin E; Hollender, Juliane

    2012-12-14

    An automated multiresidue method consisting of an online solid-phase extraction step coupled to a high performance liquid chromatography-tandem mass spectrometer (online-SPE-HPLC-MS/MS method) was developed for the determination of 88 polar organic micropollutants with a broad range of physicochemical properties (logD(OW) (pH 7): -4.2 to 4.2). Based on theoretical considerations, a single mixed-bed multilayer cartridge containing four different extraction materials was composed for the automated enrichment of water samples. This allowed the simultaneous analysis of pesticides, biocides, pharmaceuticals, corrosion inhibitors, many of their transformation products, and the artificial sweetener sucralose in three matrices groundwater, surface water, and wastewater. Limits of quantification (LOQs) were in the environmentally relevant concentration range of 0.1-87 ng/L for groundwater and surface water, and 1.5-206 ng/L for wastewater. The majority of the compounds could be quantified below 10 ng/L in groundwater (82%) and surface water (80%) and below 100 ng/L in wastewater (80%). Relative recoveries were largely between 80 and 120%. Intraday and inter-day precision, expressed as relative standard deviation, were generally better than 10% and 20%, respectively. 50 isotope labeled internal standards were used for quantification and accordingly, relative recoveries as well as intraday and inter-day precision were better for compounds with corresponding internal standard. The applicability of this method was shown during a sampling campaign at a riverbank filtration site for drinking water production with travel times of up to 5 days. 36 substances of all compound classes investigated could be found in concentrations between 0.1 and 600 ng/L. The results revealed the persistence of carbamazepine and sucralose in the groundwater aquifer as well as degradation of the metamizole metabolite 4-acetamidoantipyrine. PMID:23137864

  4. Effect of adsorbent particle size on the relative merits of a non-triangular and a triangular separation region in the optimal design of a three-zone simulated moving bed chromatography for binary separation with linear isotherms.

    Science.gov (United States)

    Mun, Sungyong

    2016-06-24

    The design approaches for a three-zone simulated moving bed (SMB) chromatography with linear isotherms can be classified into two categories, depending on whether the SMB design is based on a classical region (i.e., triangular region of the triangle theory) in the first quadrant (m2, m3) plane or on a non-triangular separation region in the third quadrant (m2, m3) plane. The SMBs based on the classical and the non-triangular design approaches, which are named here as (m(+))_SMB and (m(-))_SMB respectively, are compared in this study using the Pareto solutions from the simultaneous optimization of throughput and desorbent usage under the constraints on product purities and pressure drop. The results showed that the (m(-))_SMB approach led to significantly lower desorbent usage than the (m(+))_SMB approach, which was due to the fact that the flow-rate-ratios from the (m(-))_SMB approach are extremely lower than those from the (m(+))_SMB approach. This factor also enables the (m(-))_SMB to have a significantly lower pressure drop, thereby making its throughput less restricted by a pressure-drop constraint. Due to such advantage of the (m(-))_SMB, it can make a further substantial improvement in throughput by modulating its adsorbent particle size properly. This issue was investigated using a model separation system containing succinic acid and acetic acid. It was confirmed that if the adsorbent particle size corresponding to the boundary between a mass-transfer limiting region and a pressure-drop limiting region is adopted, the (m(-))_SMB can lead to 82% higher throughput and 73% lower desorbent usage than the (m(+))_SMB. PMID:27208988

  5. Electrostatic interactions in gas-solid chromatography.

    Science.gov (United States)

    Benson, S. W.; King, J., Jr.

    1966-01-01

    Electrostatic theory of physical adsorption applied to gas-solid chromatography, discussing chromatographic inseparability of argon and oxygen at room temperature, prediction of elution order of many gases, etc

  6. Adsorption and Transfer Properties for Toluene and p-Dichlorobenzene in Dense CO2/Silica Gel Packed Bed System by Moment Method and Time-Domain Analysis%基于矩法和时间域分析法研究稠密CO2中甲苯和对氯苯在硅胶固定床系统中的吸附和传递性质

    Institute of Scientific and Technical Information of China (English)

    杨晓宁

    2003-01-01

    Based on chromatographic theory, the moment method and the time-domain fitting analysis wereapplied to measure and evaluate the adsorption equilibrium constant and mass transfer properties (axial dispersioncoefficient and effective intra- particle diffusivity) for toluene and p-dichlorobenzene on silica gel adsorbent in thesubcritical and supercritical CO2. An apparatus based on supercritical fluid chromatography was established and theexperiments were performed at temperatures of 298.15-318.15 K and pressures of 7.5-17.8 MPa. The two methodshave been compared. The results show that for the systems studied here the moment method can give reasonablevalues for both adsorption equilibrium constant and mass transfer properties, but the time-domain analysis only canobtain the adsorption equilibrium constant. The dependence of adsorption equilibrium constant and mass transferproperties on temperature and pressure was investigated.

  7. Dynamic analysis of the CTAR (constant temperature adsorption refrigeration) cycle

    International Nuclear Information System (INIS)

    The basic SAR (solar-driven adsorption refrigeration) machine is an intermittent cold production system. Recently, the CO-SAR (continuous operation solar-powered adsorption refrigeration) system is developed. The CO-SAR machine is based on the theoretical CTAR (constant temperature adsorption refrigeration) cycle in which the adsorption process takes place at a constant temperature that equals the ambient temperature. Practically, there should be a temperature gradient between the adsorption bed and the surrounding atmosphere to provide a driving potential for heat transfer. In the present study, the dynamic analysis of the CTAR cycle is developed. This analysis provides a comparison between the theoretical and the dynamic operation of the CTAR cycle. The developed dynamic model is based on the D-A adsorption equilibrium equation and the energy and mass balances in the adsorption reactor. Results obtained from the present work demonstrate that, the idealization of the constant temperature adsorption process in the theoretical CTAR cycle is not far from the real situation and can be approached. Furthermore, enhancing the heat transfer between the adsorption bed and the ambient during the bed pre-cooling process helps accelerating the heat rejection process from the adsorption reactor and therefore approaching the isothermal process. - Highlights: • The dynamic analysis of the CTAR (constant temperature adsorption refrigeration) cycle is developed. • The CTAR theoretical and dynamic cycles are compared. • The dynamic cycle approaches the ideal one by enhancing the bed precooling

  8. Surface modification of chromatography adsorbents by low temperature low pressure plasma

    DEFF Research Database (Denmark)

    Arpanaei, Ayyoob; Winther-Jensen, Bjørn; Theodosiou, E.;

    2010-01-01

    In this study we show how low temperature glow discharge plasma can be used to prepare bi-layered chromatography adsorbents with non-adsorptive exteriors. The commercial strong anion exchange expanded bed chromatography matrix, Q HyperZ, was treated with plasmas in one of two general ways. Using...... polymer coatings (‘plasma polymerization coating’) using appropriate monomers (vinyl acetate, vinyl pyrrolidone, safrole) and argon as the carrier gas. X-ray photoelectron spectroscopy analysis (first 10 nm depth) of Q HyperZ before and after the various plasma treatments confirmed that substantial......) functions; increased exposure of the underlying yttrium-stabilised zirconia shell; and introduction of hydroxyl and carbonyl functions. Following plasma polymerization treatments (with all three monomers tested), the increased atomic percent levels of carbon and parallel drops in nitrogen, yttrium...

  9. A review of the thermodynamics of protein association to ligands, protein adsorption, and adsorption isotherms

    DEFF Research Database (Denmark)

    Mollerup, Jørgen

    2008-01-01

    The application of thermodynamic models in the development of chromatographic separation processes is discussed. The paper analyses the thermodynamic principles of protein adsorption. It can be modeled either as a reversible association between the adsorbate and the ligands or as a steady...... of adsorption is discussed. Hydrophobic and reversed phase chromatography are useful techniques for measuring solute activity coefficients at infinite dilution....

  10. 多组分吸附过程的吸附速率模型%Adsorption Rate Models for Multicomponent Adsorption Systems

    Institute of Scientific and Technical Information of China (English)

    姚春才

    2004-01-01

    Three adsorption rate models are derived for multicomponent adsorption systems under either pore diffusion or surface diffusion control. The linear driving force (LDF) model is obtained by assuming a parabolic intraparticle concentration profile. Models I and Ⅱ are obtained from the parabolic concentration layer approximation. Examples are presented to demonstrate the usage and accuracy of these models. It is shown that Model I is suitable for batch adsorption calculations and Model H provides a good approximation in fixed-bed adsorption processes while the LDF model should not be used in batch adsorption and may be considered acceptable in fixed-bed adsorption where the parameter Ti is relatively large.

  11. Effective Thermal Conductivity of Adsorbent Packed Beds

    Science.gov (United States)

    Mori, Hideo; Hamamoto, Yoshinori; Yoshida, Suguru

    The effective thermal conductivity of adsorbent packed beds of granular zeolite 13X and granular silica gel A in the presence of stagnant steam or air was measured under different conditions of the adsorbent bed temperature, particle size and filler-gas pressure. The measured effective thermal conductivity showed to become smaller with decreasing particle size or decreasing pressure, but it was nearly independent of the bed temperature. When steam was the filler-gas, the rise in the thermal conductivity of the adsorbent particles due to steam adsorption led to the increase in the effective thermal conductivity of the bed, and this effect was not negligible at high steam pressure for the bed of large particle size. It was found that both the predictions of the effective thermal conductivity by the Hayashi et al.'s model and the Bauer-Schlünder model generally agreed well with the measurements, by considering the particle thermal conductivity rise due to steam adsorption. The thermal conductivity of a consolidated bed of granular zeolite 13X was also measured, and it was found to be much larger than that of the packed bed especially at lower pressure. The above prediction models underestimated the effective thermal conductivity of the consolidated bed.

  12. Kinetics and adsorption isotherm of C-phycocyanin from Spirulina platensis on ion-exchange resins

    Directory of Open Access Journals (Sweden)

    L. Sala

    2014-12-01

    Full Text Available C-phycocyanin is a natural blue dye extracted from Spirulina platensis, which has many applications in the food and pharmaceutical industries. In this paper the effect of pH and temperature on the adsorption of C-phycocyanin onto two different ion exchange resins (Streamline DEAE and Streamline Q XL for expanded bed adsorption chromatography was investigated. Moreover, the kinetics and adsorption isotherm were evaluated. The equilibrium for the Q XL matrix was reached after 60 min, while for DEAE it was only reached after 140 min. C-phycocyanin showed the highest partition coefficient at pH 7.5 for both resins at 25 ºC. The C-phycocyanin adsorption isotherm was very well represented by the Langmuir, Freundlich and Langmuir-Freundlich models, where the estimated values for Qm and Kd obtained by the Langmuir isotherm were, respectively, 33.92 mg.mL-1 and 0.123 mg.mL-1 for DEAE, and 28.12 mg.mL-1 and 0.082 mg.mL-1 for the Q XL matrix. A negative cooperativity was observed for C-phycocyanin binding when the Q XL matrix was used, while the cooperativity was purely independent using the DEAE matrix.

  13. Large-scale Isolation and Purification of R-phycoerythrin from Red Alga Palmaria palmata Using the Expanded Bed Adsorption Method%用膨化柱填料的方法从红藻中规模分离纯化R-藻红蛋白

    Institute of Scientific and Technical Information of China (English)

    王广策; 孙海宝; 范晓; 曾呈奎

    2002-01-01

    以Phenyl-sepharose作为柱填料,用streamline柱层析技术从红藻(Palmaria palmata (Lannaeus) Kuntze)中规模分离捕光色素蛋白--R-藻红蛋白.由于不是传统的从层析柱上方进样,而是用泵将样品从streamline层析柱的下方加样(从下至上),因而解决了用一般层析柱分离R-藻红蛋白时海藻抽提液中大量的粘性多糖堵塞层析柱的难题.用P.palmata粗提液上样后,分别用0.2 mol/L、 0.1 mol/L和0.05 mol/L的(NH4)2SO4溶液从相反的方向(即从上到下)洗脱层析柱,发现这些洗脱液中的藻红蛋白纯度已经较高.然后将洗脱液透析去盐,用阴离子交换柱层析(Q-sepharose)进一步纯化.经过这两次柱层析后,R-藻红蛋白的纯度(OD565/OD280)超过3.5,高于一般认可的R-藻红蛋白的纯度标准3.2;产率为每克冷冻P.palmata可纯化0.122 mg高纯度的R-藻红蛋白,比使用一般分离方法的产率要高10倍.这些结果表明,使用本文报道的方法纯化藻红蛋白,将会使作为生化检测试剂的藻红蛋白市场价格大幅度下降.%R-phycoerythrin,a light-harvesting protein in some marine algae,and can be widely used in medicine,was isolated and purified from a red alga,Palmaria palmata (Lannaeus) Kuntze,using the streamline column (expanded bed adsorption) combined with ion-exchange chromatography.Because the crude extract was applied to the column upwardly,the column would not be blocked by polysaccharides usually very abundant in the extract of marine alga,this kind of blockage could hardly be overcome in ordinary chromatographic column.After applying the crude extract containing 0.5 mol/L (NH4)2SO4,(NH4)2SO4 solution of different concentrations (0.2 mol/L,0.1 mol/L and 0.05 mol/L) was used to elute the column downwardly and the eluates were collected and desalted.The desalted eluates were then applied onto an ion-exchange chromatographic column loaded with Q-sepharose for further purification of the R-phycoerythrin.Through these

  14. STUDIES ON THE DYNAMIC COMPETITIVE ADSORPTION OF ORGANIC VAPORS ON THE ACTIVATED CARBON FIBERS ACTIVATED WITH PHOSPHORIC ACID

    Institute of Scientific and Technical Information of China (English)

    FURuowen; LIULing; 等

    2000-01-01

    The dynamic competititve adsorption behaviors of different binary organic vapor mixtures on ACF-Ps under different operation conditons were investigated by gas chromatography in this paper,The studied mixtrues included benzene/toluene,toluene/xylene,benzene/isopropylbenzene ethly acetate/toluene and benzene/ethyl acetate.Experimental results show that various ACF-Ps,as with ACF-W,can remove both vapors in binary vapor mixtures with over 99% of removal efficiency before the breakthrough point of the more weakly adsorbed vapor,In dynamic competitive adsorption,the more weakly weakle adsorbed vapor noe only penetrates early,but also will be displaced and desorbed consequently by stronger adsorbate and therefore produces a rolling up in the breakthrough curve,The ACF-Ps prepared at different temperatuers have somewhat different adsorption selectivity,The feed concentration ratio of vapros,the length/diameter ratio and the thick of bed have effect on competitive adsorption.The competitive adsorption ability of a vapor is mainly related to its boiling point.Usually,the higher the boiling point ,the stronger the vapor adsorbed on ACF-P.

  15. Industrial wastewater treatment in fixed-bed systems

    Science.gov (United States)

    Tsatiris, Dimitris; Sidiras, Dimitris

    2012-12-01

    Fixed-bed column kinetics of methylene blue adsorption on sulfuric acid hydrolyzed pine sawdust were simulated, using untreated pine sawdust as control, in order to explore its potential use as low-cost adsorbent for wastewater dye removal in fixed-bed systems. A Severity Factor X was used to incorporate the effect of the pretreatment time and the acid concentration on the pine sawdust adsorption properties. X is an independent variable for identifying biomass adsorption parameters as affected by the acid-treatment. The estimated values of the Bohart-Adams adsorption capacity coefficient indicate that acid treatment enhanced the adsorption properties of the original material. These parameters, representing the adsorption properties improvement, exhibited a satisfactory non-linear correlation when plotted vs. X.

  16. Optimization of preparative separation and purification of total polyphenols from Sargassum tenerrimum by column chromatography

    Science.gov (United States)

    Haider, Samee; Li, Zhenxing; Lin, Hong; Jamil, Khalid

    2009-12-01

    Polyphenols from the ethanol extracts of Sargassum tenerrimum (ST) with potent antiallergic effects were studied to optimize separation process through column chromatography. The adsorption and desorption characteristics of three widely used adsorbents: macroporous resin, silica gel, and polyvinylpolypyrrolidone (PVPP), were critically evaluated respectively and studied for the optimization of preparative separation of polyphenols. Static operations on these adsorbents showed that macroporous resin had the best adsorption and desorption capability among the three adsorbents. Dynamic adsorption and desorption with macroporous resin packed column were also conducted to optimize the parameters such as: with the optimal values shown in brackets, the concentration of extract solution (4 times diluted), pH value (6-7), adsorption speed (3 BV h-1, bed volumes/per hour), concentration of ethanol (80%), elution speed (3 BV h-1) and elution volume (7 BV). The chromatographic process so optimized gave a purity of 62.43% from the crude polyphenols, providing a promising basis for large scale preparation of bioactive polyphenols upon further scaling up tests.

  17. Optimization of Preparative Separation and Purification of Total Polyphenols from Sargassum tenerrimum by Column Chromatography

    Institute of Scientific and Technical Information of China (English)

    Samee Haider; LI Zhenxing; LIN Hong; Khalid Jamil

    2009-01-01

    Polyphenols from the ethanol extracts of Sargassum tenerrimum (ST) with potent antiallergie effects were studied to optimize separation process through column chromatography. The adsorption and desorption characteristics of three widely used adsorbents: macroporous resin, silica gel, and polyvinylpolypyrrolidone (PVPP), were critically evaluated respectively and studied for the optimization of preparative separation of polyphenols. Static operations on these adsorbents showed that macroporous resin had the best adsorption and desorption capability among the three adsorbents. Dynamic adsorption and desorption with maeroporous resin packed column were also conducted to optimize the parameters such as: with the optimal values shown in brackets, the concentration of extract solution (4 times diluted), pH value (6-7), adsorption speed (3 BVh1, bed volumes/per hour), concentration of ethanol (80%), elution speed (3 BV h-1) and elution volume (7 BV). The chromatographic process so optimized gave a purity of 62.43% from the crude polyphenols, providing a promising basis for large scale preparation of bioactive polyphenols upon further scaling up tests.

  18. A dynamic multi-level model for adsorptive solar cooling

    OpenAIRE

    Santori, Giulio; Sapienza, Alessio; Freni, Angelo

    2012-01-01

    This paper focuses on the development of a dynamic multi-level model for simulating of a solar cooling system adopting an adsorption chiller. The model integrates detailed simulation of the adsorption cycle (component level) into the transient simulation of the solar cooling system (system level). The chiller investigated was a standard two bed silica gel/water unit. The model was used to ascertain the feasibility of solar-driven adsorption cooling and for optimization purposes. In the base c...

  19. EFFECT OF THE LIGAND DENSITY OF MIXED-MODE CHROMATOGRAPHY ON ADSORPTION AND CHROMATOGRAPHIC PERFORMANCE OF ANTIBODY PURIFICATION%混合模式色谱配基密度对抗体吸附分离性能的影响

    Institute of Scientific and Technical Information of China (English)

    柴东升; 史清洪; 王晓宁; 白姝

    2014-01-01

    Mixed mode chromatography (MMC) is considered as an important alternative to protein A chromatography in the capture of antibody based on advantage of chemical stability,cheap price and high selectivity.In this work,a series of novel MMC beads,AN SepFF,with 4-(1H-imidazol-1-yl) aniline (AN) ligand was prepared to evaluate the influence of ligand density on adsorption and chromatographic performance in the purification of antibody.The results indicated that there existed a critical ligand density of 21.2mmol/L in antibody adsorption on AN SepFF adsorbents.Above the critical ligand density,antibody adsorption not only was represented as much higher adsorption capacity and lower dissociation constant,but also exhibited great tolerance to salt concentration.Dynamic binding capacity (DBC) for antibody further showed that antibody had a high DBC value equivalent to commercial adsorbents.In the purification of antibody from rabbit anti-smallpox plasma,the results showed that AN SepFF chromatography had greater performance in antibody purification than commercial MEP HyperCel(R) or MabSelect SuRe chromatography.The yield of antibody reached to 91.9% in AN SepFF chromatography with ligand density of 55mmol/L.Therefore,AN SepFF adsorbents have a powerful potential in the purification of antibody.%作为蛋白A色谱的重要替代技术,混合模式色谱(mixed-mode chromatography,MMC)具有稳定、廉价和选择性好等优势.本文考察了以Sepharose Fast Flow为基质、4-(咪唑-1-基)苯胺(AN)为配基的新型色谱介质AN SepFF中配基密度对抗体吸附行为和分离性能的影响.研究结果表明,AN SepFF色谱介质在抗体吸附中具有21.2mmol/L的临界配基密度.在临界配基密度以上,抗体在色谱介质上具有较高的吸附容量和很低的解离常数并展现了相当程度的盐耐受性.动态吸附结果进一步表明,抗体的色谱介质中具有与商品化介质相当的动态吸附容量.抗体纯化的结果也表

  20. Comparison of Microwave and Conventional Driven Adsorption Heat Pump Cycle Duration

    OpenAIRE

    Demir, Hasan

    2015-01-01

    The present experimental study includes comparison of microwave regenerated and conventional heated adsorbent bed of adsorption heat pump. The novel adsorption heat pump driving with microwave heating system was designed and manufactured. Microwave oven was constructed for providing homogeneous temperature distribution in the adsorbent bed. Temperature and pressure variations in the adsorption heat pump for both microwave and conventional regenerated cycles were measured and investigated. Dur...

  1. Novel Simulated moving bed technologies

    Energy Technology Data Exchange (ETDEWEB)

    Purdue University

    2003-12-30

    Cellulose and hemicellulose from plants and other biomass can be hydrolyzed to produce sugars (i.e. glucose and xylose). Once these sugars are separated from other impurities, they can serve as feedstock in fermentation to produce ethanol (as fuels), lactic acid, or other valuable chemicals. The need for producing fuels and chemicals from renewable biomass has become abundantly clear over the last decade. However, the cost of producing fermentable sugars from biomass hydrolyzate using existing technology is relatively high and has been a major obstacle. The objective of this project is to develop an efficient and economical simulated moving bed (SMB) process to recover fermentable sugars from biomass hydrolyzate. Sulfuric acid can hydrolyze the cellulose and hemicellulose in biomass to sugars, but this process can generate byproducts such as acetic acid, and can lead to further degradation of the xylose to furfural and glucose to hydroxymethyl furfural (HMF). Also, lignin and other compounds in the biomass will degrade to various phenolic compounds. If the concentrations of these compounds exceed certain threshold levels, they will be toxic to the downstream fermentation, and will severely limit the usefulness of the derived sugars. Standard post-hydrolysis processing involves neutralization of sulfuric acid, usually with lime (calcium hydroxide). A study by Wooley et al.showed that the limed hydrolyzate gave a low ethanol yield in fermentation test (20% of theoretical yield compared to 77% of theoretical yield from fermentation of pure sugars). They showed that instead of adding lime, an ion exclusion chromatography process could be used to remove acids, as well as to isolate the sugars from the biomass hydrolyzate. In this project, we investigated the feasibility of developing an economical SMB process based on (1) a polymeric adsorbent, Dowex99, which was used by Wooley et al., (2) a second polymeric adsorbent, poly-4-vinyl pyridine (or PVP in short, Reilly

  2. Gas Chromatography.

    Science.gov (United States)

    Karasek, Francis W.; And Others

    1984-01-01

    This review covers fundamental developments in gas chromatography during 1982 and 1983. Literature is considered under these headings: columns; liguid phases; solid supports; sorption processes and solvents; open tubular column gas chromatography; instrumentation; high-resolution columns and applications; other techniques; qualitative and…

  3. Possible selective adsorption of enantiomers by Na-montmorillonite

    Science.gov (United States)

    Friebele, E.; Shimoyama, A.; Ponnamperuma, C.

    1981-01-01

    Racemic amino acids including (D,L) alpha-alamine, (D,L) alpha-aminobutyric acid, (D,L) valine, and (D,L) norvaline were incubated with Na-montmorillonite at 100% CEC at three hydrogen ion concentrations, and amino acid adsorption was determined by ion exchange chromatography. Enantiomers were analyzed by gas chromatography. Differences in the quantities of D and L enantiomers in any of the fractions was no larger than a few percent. Although a large difference in the adsorption of the amino acid enantiomers was not observed, the analysis may indicate a small preferential adsorption (0.5-2%) of L-amino acids by Na-montmorillonite.

  4. Kinetics of salicylic acid adsorption on activated carbon.

    Science.gov (United States)

    Polakovic, Milan; Gorner, Tatiana; Villiéras, Frédéric; de Donato, Philippe; Bersillon, Jean Luc

    2005-03-29

    The adsorption and desorption of salicylic acid from water solutions was investigated in HPLC microcolumns packed with activated carbon. The adsorption isotherm was obtained by the step-up frontal analysis method in a concentration range of 0-400 mg/L and was well fitted with the Langmuir equation. The investigation of rate aspects of salicylic acid adsorption was based on adsorption/desorption column experiments where different inlet concentrations of salicylic acid were applied in the adsorption phase and desorption was conducted with pure water. The concentration profiles of individual adsorption/desorption cycles data were fitted using several single-parameter models of the fixed-bed adsorption to assess the influence of different phenomena on the column behavior. It was found that the effects of axial dispersion and extraparticle mass transfer were negligible. A rate-determining factor of fixed-bed column dynamics was the kinetics of pore surface adsorption. A bimodal kinetic model reflecting the heterogeneous character of adsorbent pores was verified by a simultaneous fit of the column outlet concentration in four adsorption/desorption cycles. The fitted parameters were the fraction of mesopores and the adsorption rate constants in micropores and mesopores, respectively. It was shown that the former rate constant was an intrinsic one whereas the latter one was an apparent value due to the effects of pore blocking and diffusional hindrances in the micropores. PMID:15779975

  5. Adsorption and wetting.

    NARCIS (Netherlands)

    Schlangen, L.J.M.

    1995-01-01

    Adsorption and wetting are related phenomena. In order to improve knowledge of both and their relations, experiments, thermodynamics and a theoretical interpretation have been connected, starring n-alkanes.Starting from the Gibbs adsorption equation thermodynamic relations between vapour adsorption

  6. Improved sensitivity of the nano ultra-high performance liquid chromatography-tandem mass spectrometric analysis of low-concentrated neuropeptides by reducing aspecific adsorption and optimizing the injection solvent.

    Science.gov (United States)

    Maes, Katrien; Van Liefferinge, Joeri; Viaene, Johan; Van Schoors, Jolien; Van Wanseele, Yannick; Béchade, Guillaume; Chambers, Erin E; Morren, Hugo; Michotte, Yvette; Vander Heyden, Yvan; Claereboudt, Jan; Smolders, Ilse; Van Eeckhaut, Ann

    2014-09-19

    Obtaining maximal sensitivity of nano UHPLC-MS/MS methods is primordial to quantify picomolar concentrations of neuropeptides in microdialysis samples. Since aspecific adsorption of peptides to Eppendorf tubes, pipette tips and UHPLC vials is detrimental for method sensitivity, a strategy is presented to reduce adsorption of these peptides during standard preparation. Within this respect, all procedural steps from dissolution of the lyophilized powder until the injection of the sample onto the system are investigated. Two peptides of the neuromedin family, i.e. neuromedin B and neuromedin N, and a neuromedin N-related neuropeptide, neurotensin, are evaluated. The first part of this study outlines a number of parameters which are known to affect peptide solubility. The main focus of the second part involves the optimization of the sample composition in the UHPLC vial by using design of experiments. Contradictory findings are observed concerning the influence of acetonitrile, salts and matrix components. They are found important for injection of the peptides into the system, but crucially need to be excluded from the dilution solvent. Furthermore, the type of surface material, temperature and the pipetting protocol considerably affect the adsorption phenomenon. Statistical analysis on the results of the central composite design reveals that the highest peptide responses are obtained with the injection solvent consisting of 13.1% V/V ACN and 4.4% V/V FA. This aspect of the optimization strategy can be identified as the main contributor to the gain in method sensitivity. Since the reduction of peptide adsorption and the optimization of the injection solvent resulted in a clear and quantifiable signal of the three peptides, optimization of both issues should be considered in the early stage of method development, in particular when the analysis of low-concentration peptide solutions is envisaged. PMID:25145562

  7. Dynamics of CO 2 Adsorption on Amine Adsorbents. 1. Impact of Heat Effects

    KAUST Repository

    Bollini, Praveen

    2012-11-21

    The packed bed heat and mass transfer dynamics of CO2 adsorption onto a 3-aminopropylsilyl-functionalized SBA-15 silica material are reported. Concentration measurements at the outlet of the packed bed and temperature profiles inside the bed are measured simultaneously. Heat and mass transfer models in conjunction with the linear driving force rate model are used to simulate the concentration and temperature profiles in the bed. The heat and mass transfer processes in the amine adsorbent packed bed are successfully captured by the model, and comparison of isothermal and nonisothermal models reveals that isothermal models provide an accurate description of the dynamic mass transport behavior in the adsorption column under the experimental conditions used in this study. The results help establish that under certain experimental conditions, heat effects in amine adsorbent packed beds have a negligible effect on CO2 breakthrough, and simple isothermal models can be used to accurately assess adsorption kinetics. © 2012 American Chemical Society.

  8. ISOLATION AND PURIFICATION OF ALKALOIDS FROM PLUMULA NELUMBINIS BY DOUBLE-COLUMN ADSORPTION CHROMOTOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jixiang; GUO Jinsheng; OU Lailiang

    2007-01-01

    The performance of adsorption and separation for liensinine, isoliensinine and neferine was studied by double-column adsorption chromatography using macroporous adsorption and cation exchange resins. The alkaloid extract with 49.2% total contents by mass representing 10.6% liensinine, 10.6% isoliensinine and 28.0% neferine respectively was prepared by D72 cation exchange resins, in which most of the impurities were water-soluble alkaloids. Furthermore, the alkaloid extract with 82.6% total contents by mass containing 33.1%, 15.0% and 34.5% of the three adsorbates respectively was prepared by double-column adsorption chromatography using AKS-W macroporous adsorption and D72 cation exchange resins. As a result, the content of single and total alkaloids has been greatly increased by the double-column adsorption chromatography.

  9. ISOLATION AND PURIFICATION OF ALKALOIDS FROM PLUMULA NELUMBINIS BY DOUBLE-COLUMN ADSORPTION CHROMOTOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The performance of adsorption and separation for liensinine, isoliensinine and neferine was studied by double-column adsorption chromatography using macroporous adsorption and cation exchange resins. The alkaloid extract with 49.2% total contents by mass representing 10.6% liensinine, 10.6% isoliensinine and 28.0% neferine respectively was prepared by D72 cation exchange resins, in which most of the impurities were water-soluble alkaloids. Furthermore,the alkaloid extract with 82.6% total contents by mass containing 33.1%, 15.0% and 34.5% of the three adsorbates respectively was prepared by double-column adsorption chromatography using AKS-W macroporous adsorption and D72 cation exchange resins. As a result, the content of single and total alkaloids has been greatly increased by the double-column adsorption chromatography.

  10. Study on the Mechanism of Competitive Adsorption of Circulating Fluidized Bed Ash and Cement to Poly Carboxylic Acid Water Reducing Agent%循环流化床灰对聚羧酸减水剂竞争吸附的影响研究

    Institute of Scientific and Technical Information of China (English)

    陈敏; 宋少民; 高霞

    2012-01-01

    In order to study on the effect of competitive adsorption of circulating fluidized bed ash and cement to poly carboxylic acid water reducing agent, by adding anhydrous sodium sulfate, dihydrate calcium sulphate and iron oxide into grade 11 fly ash to change the content of sulfur trioxide and iron oxide, its chemical composition close to circulating fluidized bed ash's is made, and the fuidity of cement past, zeta potential adding and concrete performance are tested. The results show that the dissolved sulfate and iron oxide in circulating fluidized bed ash have negative impact on adsorption of poly carboxylic acid water reducing agent. When the dosage of dissolved sulfate and iron oxide respectively reach 3% ,6% of the total cementing material,the corresponding paste both lost fluidity. Zeta potential tests indicate that the absolute of zeta potential gets smaller as the increase of dosage of dissolved sulfate and iron oxide, meanwhile repulsion between particles gets weaker, and dispersion becomes worse and dispersion system was more unstable. Concrete performance experiments show that the fluidity and compressive strength of concrete become smaller as sodium sulfate and iron oxide are incorporated in grade II fly ash, stump decreased from 220 mm to 125 mm, the highest strength reduce reached to 45%.%为研究循环流化床灰对聚羧酸减水剂竞争吸附的影响,通过在Ⅱ级粉煤灰中掺加无水硫酸纳、二水硫酸钙和氧化铁的方式来改变粉煤灰中三氧化硫和氧化铁含量,使其化学成分接近循环流化床灰,利用成分单因素分析的方法,测试减水剂水泥浆体的净浆流动度、Zeta电位和混凝土性能.研究结果表明循环流化床灰中的三氧化硫和氧化铁对聚羧酸减水剂的吸附有明显负面影响,当可溶性硫酸盐掺量达到胶凝材料的3%、氧化铁掺量达到6%时,相应浆体均失去流动性.Zeta电位试验表明随着无水硫酸钠和氧化铁掺

  11. Preparative separation of gallocatechin gallate from Camellia ptilophylla using macroporous resins followed by sephadex LH-20 column chromatography.

    Science.gov (United States)

    Li, Kaikai; Zhou, Xuelin; Liu, Cheuk-Lun; Yang, Xiaorong; Han, Xiaoqiang; Shi, Xianggang; Song, Xiaohong; Ye, Chuangxing; Ko, Chun-hay

    2016-02-01

    Gallocatechin gallate (GCG) possesses multiple potential biological activities. However, the content of GCG in traditional green tea is too low which limits its in-depth pharmacological research and application. In the present study, a simple, efficient and environment-friendly chromatographic separation method was developed for preparative enrichment and separation of GCG from cocoa tea (Camellia ptilophylla) which contains high content of GCG. In the first step, the adsorption properties of selected resins were evaluated, and XAD-7HP resin was chosen by its adsorption and desorption properties for GCG. In order to maximize column efficiency for GCG collection, the operating parameters (e.g., flow rate, ethanol concentration, and bed height) were optimized. We found that the best combination was the feed concentration at 20mg/mL, flow rate at 0.75 BV/h and the ratio of diameter to bed heights as 1:12. Under these conditions, the purity of GCG was 45% with a recovery of 89%. In order to obtain pure target, a second step was established using column chromatography with sephadex LH-20 gel and 55% ethanol-water solution as eluent. After this step, the purity of the GCG was 91% with a recovery of 68% finally.

  12. Adsorption and desorption characteristics of crystal violet in bottom ash column

    Directory of Open Access Journals (Sweden)

    Puthiya Veetil Nidheesh

    2012-06-01

    Full Text Available This study described adsorption of Crystal Violet (CV by bottom ash in fixed-bed column mode. Equilibrium of adsorption was studied in batch mode for finding adsorption capacity of bottom ash. In fixed bed column adsorption, the effects of bed height, feed flow rate, and initial concentration were studied by assessing breakthrough curve. The slope of the breakthrough curve decreased with increasing bed height. The breakthrough time and exhaustion time were decreased with increasing influent CV concentration and flow rates. The effect of bed depth, flow rate and CV concentration on the adsorption column design parameters were analyzed. Bed depth service time (BDST model was applied for analysis of crystal violet adsorption in the column. The adsorption capacity of bottom ash was calculated at 10% breakthrough point for different flow rates and concentrations. Desorption studies reveals that recovery of CV from bottom ash was effective by using CH3COOH than H2SO4, NaOH, HCl and NaCl solutions.

  13. ADSORPTION AND DESORPTION CHARACTERISTICS OF CRYSTAL VIOLET IN BOTTOM ASH COLUMN

    Directory of Open Access Journals (Sweden)

    Puthiya Veetil Nidheesh

    2012-01-01

    Full Text Available This study described adsorption of Crystal Violet (CV by bottom ash in fixed-bed column mode. Equilibrium of adsorption was studied in batch mode for finding adsorption capacity of bottom ash. In fixed bed column adsorption, the effects of bed height, feed flow rate, and initial concentration were studied by assessing breakthrough curve. The slope of the breakthrough curve decreased with increasing bed height. The breakthrough time and exhaustion time were decreased with increasing influent CV concentration and flow rates. The effect of bed depth, flow rate and CV concentration on the adsorption column design parameters were analyzed. Bed depth service time (BDST model was applied for analysis of crystal violet adsorption in the column. The adsorption capacity of bottom ash was calculated at 10% breakthrough point for different flow rates and concentrations. Desorption studies reveals that recovery of CV from bottom ash was effective by using CH3COOH than H2SO4, NaOH, HCl and NaCl solutions.

  14. Gas chromatography

    Science.gov (United States)

    Guiochon, Georges; Guillemin, Claude L.

    1990-11-01

    Gas chromatography is a powerful separation technique for gas and vapor mixtures. Combining separation and on-line detection permits accurate quantitative analysis of complex mixtures, including traces of compounds down to parts per trillions in some particular cases. The importance of gas chromatography in quality control and process control in the chemical and drug industry, in environmental pollution investigations and in clinical analysis is critical. The principles of the technique are discussed, the main components of a gas chromatograph are described and some idea of the importance of the applications is given.

  15. Adsorption and wetting.

    OpenAIRE

    Schlangen, L.J.M.

    1995-01-01

    Adsorption and wetting are related phenomena. In order to improve knowledge of both and their relations, experiments, thermodynamics and a theoretical interpretation have been connected, starring n-alkanes.Starting from the Gibbs adsorption equation thermodynamic relations between vapour adsorption and wetting are derived. The surface pressure of a film, formed by vapour adsorption on a solid surface, is calculated by integrating the vapour adsorption isotherm. The surface pressure at the sat...

  16. Adsorption and strain: The CO 2-induced swelling of coal

    Science.gov (United States)

    Vandamme, M.; Brochard, L.; Lecampion, B.; Coussy, O.

    2010-10-01

    Enhanced coal bed methane recovery (ECBM) consists in injecting carbon dioxide in coal bed methane reservoirs in order to facilitate the recovery of the methane. The injected carbon dioxide gets adsorbed at the surface of the coal pores, which causes the coal to swell. This swelling in confined conditions leads to a closure of the coal reservoir cleat system, which hinders further injection. In this work we provide a comprehensive framework to calculate the macroscopic strains induced by adsorption in a porous medium from the molecular level. Using a thermodynamic approach we extend the realm of poromechanics to surface energy and surface stress. We then focus on how the surface stress is modified by adsorption and on how to estimate adsorption behavior with molecular simulations. The developed framework is here applied to the specific case of the swelling of CO 2-injected coal, although it is relevant to any problem in which adsorption in a porous medium causes strains.

  17. Ion Chromatography.

    Science.gov (United States)

    Mulik, James D.; Sawicki, Eugene

    1979-01-01

    Accurate for the analysis of ions in solution, this form of analysis enables the analyst to directly assay many compounds that previously were difficult or impossible to analyze. The method is a combination of the methodologies of ion exchange, liquid chromatography, and conductimetric determination with eluant suppression. (Author/RE)

  18. Coal bed methane potential and biogasification of soma lignite

    OpenAIRE

    Baysal, Mustafa

    2012-01-01

    Coal bed methane (CBM) can arise from both thermogenic and biogenic activity on the coal beds and adsorb on the porous matrix of the coal. Therefore, investigation of pore structure and gas capacity of the coal is essential for accurate estimations of coal bed gas potential. Coal samples of lignite to sub-bituminous rank were obtained from different depths of Soma basin and were characterized by low pressure CO2 adsorption isotherms at 273 K. Micropore surface areas of the samples were calcul...

  19. Agro-industrial waste: a low cost adsorbent for effective removal of 4-chloro-2-methylphenoxyacetic acid herbicide in batch and packed bed modes.

    Science.gov (United States)

    Deokar, Sunil K; Mandavgane, Sachin A; Kulkarni, Bhaskar D

    2016-08-01

    The present work describes the aqueous phase removal of 4-chloro-2-methylphenoxyacetic acid herbicide by rice husk ash (RHA) using batch and packed bed adsorption techniques. The effects of dosage, initial concentration, time, pH, temperature, and particle size of adsorbent in batch compared with effects of influent concentration, flow rate, and bed height in packed bed were studied. The particle size effect reveals that the removal is dependent on chemical composition (silica and carbon content) together with BET surface area of RHA. The aptness of Langmuir isotherm to batch data indicates the favorable adsorption whereas that of Temkin isotherm informs the heterogeneous nature of RHA. The kinetics of adsorption follows the pseudo-second order and Elovich models while thermodynamics of process indicates the exothermic adsorption. Among the models applied in packed bed study, the deactivation kinetic, Yoon-Nelson and bed depth service time (BDST) models are suitable to explain the packed bed adsorption. The adsorption capacity of RHA in packed bed study is found greater than that in batch. The adsorption capacity of RHA determined by the BDST model is 3019 mg/L for 90 % saturation of bed. The adsorption capacity of RHA based on weight is ∼2.3 times and that based on surface area is ∼55.55 times greater than that of granular activated carbon. PMID:27151241

  20. Adamantyl-group containing mixed-mode acrylamide-based continuous beds for capillary electrochromatography. Part II. Characterization of the synthesized monoliths by inverse size exclusion chromatography and scanning electron microscopy.

    Science.gov (United States)

    Ayat Allah Al-Massaedh; Pyell, Ute

    2014-01-17

    In our previous article we have described the synthesis of a new amphiphilic monolithic stationary phase by in situ free radical copolymerization of cyclodextrin-solubilized N-adamantyl acrylamide, piperazinediacrylamide, methacrylamide and vinylsulfonic acid in aqueous medium in pre-treated fused silica capillaries of 100μm I.D. In the present work, we study the morphology of different monolithic stationary phases synthesized under variation of the concentration of ammonium sulfate in the polymerization mixture. The pore size distribution is determined with inverse size exclusion chromatography (ISEC) using the retention data of a series of polystyrene standards with narrow molecular size distribution and known average molar mass ranging from 1560 to 2010000gmol(-1). The impact of the concentration of the lyotropic salt ammonium sulfate in the polymerization mixture on the formed morphology, the pore size distribution, and the fractional volume of mesopores and macropores is determined. The homogeneity and uniformity of the formed monolith over the length of the capillary and the covalent attachment to the confining walls are confirmed. Repetition of the synthesis procedure shows that these morphology parameters are well controlled as there is an excellent capillary-to-capillary, day-to-day, and run-to-run reproducibility reached for the electroosmotic mobility and the retention factor determined with alkylphenones in the reversed-phase mode. PMID:24380653

  1. Computer-aided model analysis for ionic strength-dependent effective charge of protein in ion-exchange chromatography

    DEFF Research Database (Denmark)

    Lim, Young-il; Jørgensen, Sten Bay; Kim, In-Ho

    2005-01-01

    A packed-bed chromatographic model developed in this study includes adsorption isotherms considering steric mass action (SMA) as well as non-linearity in liquid/solid phases, adsorption kinetics and mass transport. For solving the nonlinear and nonequilibrium adsorption model described by a partial...

  2. Mass transfer and adsorption equilibrium study in MFI zeolites: application to the separation of mono and di-branched hydrocarbons in silicalite; Etude et modelisation de l'adsorption et du transfert de matiere dans les zeolithes de structure MFI. Application a la separation des hydrocarbures satures mono et di-branches

    Energy Technology Data Exchange (ETDEWEB)

    Jolimaitre, E.

    1999-11-30

    The aim of this study was to develop a model representing the breakthrough of hydrocarbon mixtures in fixed bed, and to estimate the parameters of this model. Equilibrium isotherms and effective diffusivities of 3-methyl-pentane, isopentane and 2,2-dimethyl-butane in silicalite were measured between 150 and 300 deg. C and for different concentrations, with a linear chromatography technique. Parameter estimation was made by mean of a linear model developed for this work, on which a parameter identifiability study was made. The method used for the parameter identifiability study can be applied to any linear fixed bed model. Experimental single component and mixtures breakthrough curves of 2-methyl-pentane, isopentane and 2,2-dimethyl-butane were then realized at 200 deg. C. Adsorption isotherms and self diffusivities were estimated from single-component curves, using a non linear model of the bed. The non-linear model was also developed and validated during this work. These parameters were injected into the non-linear model to simulate the experimental mixture breakthrough curves. Influence of the velocity variation in the bed and of the diffusion driving-force (Maxwell-Stefan or Fick theory) was studied. Most of the experimental breakthrough curves are correctly predicted by the model, expect for the isopentane-2,2-dimethyl-butane mixture, for which predicted breakthrough time is inferior to experimental values. (author)

  3. Adsorption of phenol and chlorophenols on pure and modified sepiolite

    OpenAIRE

    Yildiz, A; A. GÜR

    2007-01-01

    In this work, pure sepiolite and sepiolite modified by nitric acid (HNO3), ethylenediaminetetraacetic acid (EDTA) and hexadecyltrimethyl-ammonium (HDTMA) were used ad adsorbents. The changes on the surface were studied by IR spectroscopy. The adsorption of solutions of phenol and phenol derivatives in pure ethanol on these adsorbents were examined by means of gas chromatography. It was found that the adsorption capacities of the clay–organic complexes (sepiolite–EDTA and sepiolite–HDTMA) were...

  4. Top Ten Bed Bug Tips

    Science.gov (United States)

    ... have bed bugs, not fleas, ticks or other insects. You can compare your insect to the pictures on our Identifying bed bugs ... bedbugs Bed Bugs Home Learn about Bed Bugs — Characteristics of Bed Bugs — Finding Bed Bugs Protecting Your ...

  5. Defluoridation of drinking water using adsorption processes

    International Nuclear Information System (INIS)

    Highlights: ► Comprehensive and critical literature review on various adsorbents used for defluoridation. ► pH, temperature, kinetics and co-existing anions effects on F adsorption. ► Choice of adsorbents for various circumstances. ► Adsorption thermodynamics and mechanisms. ► Future research on efficient, low cost adsorbents which are easily regenerated. -- Abstract: Excessive intake of fluoride (F), mainly through drinking water, is a serious health hazard affecting humans worldwide. There are several methods used for the defluoridation of drinking water, of which adsorption processes are generally considered attractive because of their effectiveness, convenience, ease of operation, simplicity of design, and for economic and environmental reasons. In this paper, we present a comprehensive and a critical literature review on various adsorbents used for defluoridation, their relative effectiveness, mechanisms and thermodynamics of adsorption, and suggestions are made on choice of adsorbents for various circumstances. Effects of pH, temperature, kinetics and co-existing anions on F adsorption are also reviewed. Because the adsorption is very weak in extremely low or high pHs, depending on the adsorbent, acids or alkalis are used to desorb F and regenerate the adsorbents. However, adsorption capacity generally decreases with repeated use of the regenerated adsorbent. Future research needs to explore highly efficient, low cost adsorbents that can be easily regenerated for reuse over several cycles of operations without significant loss of adsorptive capacity and which have good hydraulic conductivity to prevent filter clogging during the fixed-bed treatment process

  6. Surface Chemistry of Polymers Physical Adsorption of Nitrogen, Argon, Sulfur Dioxide and Neopentane on Polyvinylidene Fluoride

    OpenAIRE

    Houriet, Jean-Philippe; Ghiste, Patrick; Stoeckli, Fritz

    2007-01-01

    The adsorption of nitrogen, argon, sulfur dioxide and neopentane on polyvinylidene fluoride has been measured by static methods and by gas-solid chromatography. The polymer has a homogeneous surface of low energy, which is not significantly affected by heating.

  7. The Development of Gel Media and Columns for Large-Scale Chromatography of Proteins,a Historical Review

    Institute of Scientific and Technical Information of China (English)

    Jan-Christer; Janson

    2002-01-01

    Thr first dedicated protein chromatography media were introduced during the 1950s and 1960s.There was an early awareness of the possibility of using these for production applications within the biopharmaceutical industry.However,the crucial limitation was the fact that those media that were most compatible with proteins lent themselves less favourably to scaling-up.The problems were primarily physical.Thus the fibrous cellulose media showed bed cracking tendencies and the bead shaped polyacrylamide.dextran,and agarose gel media,then available, were too soft to stand the hydrodynamic forces acting in large columns,leading to bed compaction and increased pressure drop.At the time,the best solution to the latter problem,after a number of intermediary solutions were tried,was the introductionof the stacked column concept in which several short column segments were connected by small bore tubing,thus reducing the force acting on the particles in each bed com partment,However,the ultimate remedy,the introduction of chromatographic matrices that combine the desired features of adequate rigidity,macroporosity,biocompatibility,chemical stability(for CIP and SIP0and derivatizability,did not occur until the middle of the 1980s when adequately cross-linked agarose gel media such as Sepharose Fast Flow were made available.The paper also recognizes the many attempts made during the past 50 years to develop continous chromatography columns.Most of the designs are based on an annular bed or on an array of annularly arranged parallel columns continuously fed with samples in a cyclic manner.The introduction of media and columns for expanded bed adsorption followed a demand for rewer pruification steps and shorter process times.In recent years,columns have been ntroduced that allow packing and repacking without needing to open the column.The review provides an historical account of the developments that have led to the present state-of-the-art both regarding large diameter columns

  8. Activated Carbon Adsorption Properties of the Residual Matters in Textile Dyeing and Printing Secondary Effluent

    Institute of Scientific and Technical Information of China (English)

    TIAN Qing; LI Fang; LIU Fang; YANG Bo; CHEN Ji-hua

    2008-01-01

    The research employed the adsorption isotherm measurement, the batch kinetic adsorption and the rapid small-scale carbon column test (RSSCT) to find out the characteristics and main impacting factors of granular activated carbon (GAC) adsorption, in treating the textile dyeing-printing/polyester alkali de-weighting secondary effluent (TSE). The adsorption affinities and capacities for the organics surrogated by CODCr, color and UV254 (UV absorbency at λ= 254 nm) predicted by isotherm, small-scale-fixed bed were discussed. Adsorption rates for CODCr, color and UV254 are much different and carbon particle size dependent. The color adsorption rate and capacity should be taken as the main consideration factors in designing bio-activated carbon filter(BACF). The breakthrough of GAC adsorption column is mainly influenced by the low MW readily adsorbable organics in TSE. UVm is a good adsorption breakthrough indicator. The study provides References for BACFs' design and operation control in textile secondary effluent (TSE) tertiary treatment.

  9. Mixed hemimicelles solid-phase extraction based on sodium dodecyl sulfate-coated nano-magnets for selective adsorption and enrichment of illegal cationic dyes in food matrices prior to high-performance liquid chromatography-diode array detection detection.

    Science.gov (United States)

    Qi, Ping; Liang, Zhi-an; Wang, Yu; Xiao, Jian; Liu, Jia; Zhou, Qing-qiong; Zheng, Chun-hao; Luo, Li-Ni; Lin, Zi-hao; Zhu, Fang; Zhang, Xue-wu

    2016-03-11

    In this study, mixed hemimicelles solid-phase extraction (MHSPE) based on sodium dodecyl sulfate (SDS) coated nano-magnets Fe3O4 was investigated as a novel method for the extraction and separation of four banned cationic dyes, Auramine O, Rhodamine B, Basic orange 21 and Basic orange 22, in condiments prior to HPLC detection. The main factors affecting the extraction of analysts, such as pH, surfactant and adsorbent concentrations and zeta potential were studied and optimized. Under optimized conditions, the proposed method was successful applied for the analysis of banned cationic dyes in food samples such as chili sauce, soybean paste and tomato sauce. Validation data showed the good recoveries in the range of 70.1-104.5%, with relative standard deviations less than 15%. The method limits of determination/quantification were in the range of 0.2-0.9 and 0.7-3μgkg(-1), respectively. The selective adsorption and enrichment of cationic dyes were achieved by the synergistic effects of hydrophobic interactions and electrostatic attraction between mixed hemimicelles and the cationic dyes, which also resulted in the removal of natural pigments interferences from sample extracts. When applied to real samples, RB was detected in several positive samples (chili powders) within the range from 0.042 to 0.177mgkg(-1). These results indicate that magnetic MHSPE is an efficient and selective sample preparation technique for the extraction of banned cationic dyes in a complex matrix. PMID:26877180

  10. Adsorption Characteristics of H2 on Molecular Sieves 5A at 77 K

    Institute of Scientific and Technical Information of China (English)

    XIA; Ti-rui; YANG; Hong-guang; LIU; Wen-jun; LIU; Zhen-xing; ZHAO; Wei-wei; HAN; Zhi-bo

    2013-01-01

    With the aim of applying cryogenic molecular sieves bed(CMSB)to a tritium extraction system(TES)for ITER TBM,adsorption characteristics of H2 on a molecular sieve at 77 K was investigated by a volumetric method.The adsorption isotherms for H2 in a pressure range between about 1 and 103 Pa was shown in Fig.1,and alkaline treatment(CaA includes not only Na+but also Ca2+)improved the adsorption

  11. Equilibrium adsorption data from temperature-programmed desorption experiments

    NARCIS (Netherlands)

    Foeth, Frank; Mugge, José; Vaart, van der Rick; Bosch, Hans; Reith, Tom

    1996-01-01

    This work describes a novel method that enables the calculation of a series of adsorption isotherms basically from a single Temperature-Programmed Desorption (TPD) experiment. The basic idea is to saturate an adsorbent packed in a fixed bed at a certain feed concentration and temperature and to subs

  12. Cuticular hydrocarbons from the bed bug Cimex lectularius L.

    Science.gov (United States)

    Pentane extracts of male and female bed bugs were analyzed by gas chromatography and mass spectrometry in an effort to identify cuticular hydrocarbons. Seventeen hydrocarbons accounting for nearly 99% of the compounds eluting in the cuticular hydrocarbon region were identified. The sample contained ...

  13. Volatile organic compounds adsorption onto neat and hybrid bacterial cellulose

    Science.gov (United States)

    Ion, Violeta Alexandra; Pârvulescu, Oana Cristina; Dobre, Tănase

    2015-04-01

    Adsorption dynamics of VOCs (volatile organic compounds) vapour from air streams onto fixed bed adsorbent were measured and simulated under various operation conditions. Isopropanol (IPA) and n-hexane (HEX) were selected as representatives of polar and nonpolar VOCs, whereas bacterial cellulose (BC) and BC incorporated with magnetite nanoparticles (M/BC), were tested as adsorbents. An experimental study emphasizing the influence of air superficial velocity (0.7 cm/s and 1.7 cm/s), operation temperature (30 °C and 40 °C), adsorbate and adsorbent type, on fixed bed saturation curves was conducted. Optimal adsorption performances evaluated in terms of saturation adsorption capacity were obtained for the adsorption of polar compound (IPA) onto M/BC composite (0.805 g/g) and of nonpolar compound (HEX) onto neat BC (0.795 g/g), respectively, at high values of air velocity and operation temperature. A mathematical model including mass balance of VOC species, whose parameters were fitted based on experimental data, was developed in order to predict the fixed bed saturation curves. A 23 statistical model indicating a significant increase in adsorption performances with process temperature was validated under the experimental conditions.

  14. Adsorption Model for Off-Gas Separation

    Energy Technology Data Exchange (ETDEWEB)

    Veronica J. Rutledge

    2011-03-01

    The absence of industrial scale nuclear fuel reprocessing in the U.S. has precluded the necessary driver for developing the advanced simulation capability now prevalent in so many other countries. Thus, it is essential to model complex series of unit operations to simulate, understand, and predict inherent transient behavior and feedback loops. A capability of accurately simulating the dynamic behavior of advanced fuel cycle separation processes will provide substantial cost savings and many technical benefits. The specific fuel cycle separation process discussed in this report is the off-gas treatment system. The off-gas separation consists of a series of scrubbers and adsorption beds to capture constituents of interest. Dynamic models are being developed to simulate each unit operation involved so each unit operation can be used as a stand-alone model and in series with multiple others. Currently, an adsorption model has been developed in gPROMS software. Inputs include gas stream constituents, sorbent, and column properties, equilibrium and kinetic data, and inlet conditions. It models dispersed plug flow in a packed bed under non-isothermal and non-isobaric conditions for a multiple component gas stream. The simulation outputs component concentrations along the column length as a function of time from which the breakthrough data is obtained. It also outputs temperature along the column length as a function of time and pressure drop along the column length. Experimental data will be input into the adsorption model to develop a model specific for iodine adsorption on silver mordenite as well as model(s) specific for krypton and xenon adsorption. The model will be validated with experimental breakthrough curves. Another future off-gas modeling goal is to develop a model for the unit operation absorption. The off-gas models will be made available via the server or web for evaluation by customers.

  15. Adsorption Model for Off-Gas Separation

    International Nuclear Information System (INIS)

    The absence of industrial scale nuclear fuel reprocessing in the U.S. has precluded the necessary driver for developing the advanced simulation capability now prevalent in so many other countries. Thus, it is essential to model complex series of unit operations to simulate, understand, and predict inherent transient behavior and feedback loops. A capability of accurately simulating the dynamic behavior of advanced fuel cycle separation processes will provide substantial cost savings and many technical benefits. The specific fuel cycle separation process discussed in this report is the off-gas treatment system. The off-gas separation consists of a series of scrubbers and adsorption beds to capture constituents of interest. Dynamic models are being developed to simulate each unit operation involved so each unit operation can be used as a stand-alone model and in series with multiple others. Currently, an adsorption model has been developed in gPROMS software. Inputs include gas stream constituents, sorbent, and column properties, equilibrium and kinetic data, and inlet conditions. It models dispersed plug flow in a packed bed under non-isothermal and non-isobaric conditions for a multiple component gas stream. The simulation outputs component concentrations along the column length as a function of time from which the breakthrough data is obtained. It also outputs temperature along the column length as a function of time and pressure drop along the column length. Experimental data will be input into the adsorption model to develop a model specific for iodine adsorption on silver mordenite as well as model(s) specific for krypton and xenon adsorption. The model will be validated with experimental breakthrough curves. Another future off-gas modeling goal is to develop a model for the unit operation absorption. The off-gas models will be made available via the server or web for evaluation by customers.

  16. Bed In Summer

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In winter I get up at night And dress by yellow candle-light. In summer, quite the other way, I have to go to bed by day. I have to go to bed and see The birds still hopping on the tree, Or hear the grown-up people' s feet Still going past me in the stree

  17. Fluidized bed incinerator development

    International Nuclear Information System (INIS)

    A fluidized bed incinerator is being developed for burning rad contaminated solid and liquid waste materials. In situ neutralization of acid gases by the bed material, catalytic afterburning, and gas filtration are used to produce a clean flue gas without the use of aqueous scrubbing

  18. Fluidized bed calciner apparatus

    Science.gov (United States)

    Owen, Thomas J.; Klem, Jr., Michael J.; Cash, Robert J.

    1988-01-01

    An apparatus for remotely calcining a slurry or solution feed stream of toxic or hazardous material, such as ammonium diurante slurry or uranyl nitrate solution, is disclosed. The calcining apparatus includes a vertical substantially cylindrical inner shell disposed in a vertical substantially cylindrical outer shell, in which inner shell is disposed a fluidized bed comprising the feed stream material to be calcined and spherical beads to aid in heat transfer. Extending through the outer and inner shells is a feed nozzle for delivering feed material or a cleaning chemical to the beads. Disposed in and extending across the lower portion of the inner shell and upstream of the fluidized bed is a support member for supporting the fluidized bed, the support member having uniform slots for directing uniform gas flow to the fluidized bed from a fluidizing gas orifice disposed upstream of the support member. Disposed in the lower portion of the inner shell are a plurality of internal electric resistance heaters for heating the fluidized bed. Disposed circumferentially about the outside length of the inner shell are a plurality of external heaters for heating the inner shell thereby heating the fluidized bed. Further, connected to the internal and external heaters is a means for maintaining the fluidized bed temperature to within plus or minus approximately 25.degree. C. of a predetermined bed temperature. Disposed about the external heaters is the outer shell for providing radiative heat reflection back to the inner shell.

  19. Removal of green 40 from aqueous solutions by adsorption using organo-corn straw

    Directory of Open Access Journals (Sweden)

    Chakkrit Umpuch

    2015-09-01

    Full Text Available The objective of this study was to investigate the adsorption characteristics of green 40 on organo-corn straw which was prepared by means of adsolubilization in batch tests and fixed bed column experiments. The batch tests were studied as functions of contact times (t, initial pH solutions (pH0, and initial dye concentrations (Ce. The adsorption reached equilibrium within 5 h and the amount of the dye adsorbed decreased with increases in pH0. The adsorption isotherm followed Langmuir and Freundlich isotherms and the kinetic data obeyed the pseudo-second order kinetic model. The fixed bed experiments were carried out as functions of inlet dye concentrations, liquid flow rates, and bed heights. The breakthrough point appeared faster with increases in liquid flow rates and inlet dye concentrations, but presented more slowly with increases in bed heights. It was found that the highest adsorption capacity of 152.75 mg/g was obtained under the condition of inlet dye concentration of 200 mg/L, bed height of 16 cm, and flow rate of 3.5 mL/min. The adsorption data were fitted to three well-established fixedbed adsorption models, Adams-Bohart, Thomas, and Yoon-Nelson models with good coefficients. The results showed that organo-corn straw can be used as an effective biosorbent for the removal of green 40 from wastewater.

  20. The thermodynamic principles of ligand binding in chromatography and biology

    DEFF Research Database (Denmark)

    Mollerup, Jørgen

    2007-01-01

    In chromatography, macromolecules do not adsorb in the traditional sense of the word but bind to ligands that are covalently bonded to the surface of the porous bead. Therefore, the adsorption must be modelled as a process where protein molecules bind to the immobilised ligands. The paper discusses...... the general thermodynamic principles of ligand binding. Models of the multi-component adsorption in ion-exchange and hydrophobic chromatography, HIC and RPLC, are developed. The parameters in the models have a well-defined physical significance. The models are compared to the Langmuir model...... but it is also observed in chromatography due to protein-protein interactions. Retention measurements on P-lactoglobulin A demonstrate this. A discussion of salt effects on hydrophobic interactions in precipitation and chromatography of proteins concludes the paper. (c) 2007 Elsevier B.V. All rights reserved....

  1. BRIEF COMMUNICATIONS: Laser chromatography (negative results)

    Science.gov (United States)

    Kuz'menko, V. A.

    1989-11-01

    An experimental study was made of the influence of cw CO2 laser radiation on gas-adsorption chromatography of SF6, CH2Cl2, and BCl3. Resonant excitation of molecules by laser radiation did not alter the duration of their retention in a chromatograph column. A reduction in the retention time was attributed to nonresonant heating of the column walls by laser radiation.

  2. Review of the adsorption of radioactive krypton and xenon on activated charcoal

    International Nuclear Information System (INIS)

    This report summarizes the results of a critical review of the published literature on the adsorption of radioactive krypton and xenon on activated charcoal. This review, which was supported by the Advisory Committee on Reactor Safeguards, US Nuclear Regulatory Commission, showed that (a) individual charcoals have a wide range of adsoprtion coefficients and therefore the performance of a given bed is heavily dependent on the quality of the charcoal it contains; (b) because of the detrimental effects of mass transfer on noble gas adsorption, consideration should be given to including this factor in developing technical specifications for adsorption beds; and (c) additional research is needed on the determination of the inter-relationship of moisture and temperature and their effects on adsorption bed performance

  3. Study of a silica gel-water based dual mode adsorption chiller

    Directory of Open Access Journals (Sweden)

    Khairul Habib

    2016-04-01

    Full Text Available This article presents analytical investigation results on the performance of dual-mode multi-bed adsorption cooling systems using silica gel-water pair. This novel adsorption chiller utilizes effectively low-temperature solar or waste heat sources of temperature between 40 and 85°C. Two operation modes are possible for the advanced chiller. The first operation mode will be to work as a highly efficient conventional chiller where the driving source temperature is between 60 and 85°C. The second operation mode will be to work as an advanced two-stage adsorption chiller where the available driving source temperature is very low (below 60°C. In the present work, a simulation study of a dualmode, four-bed silica gel-water adsorption chiller is undertaken. For a driving source temperature above 60°C, the chiller functions as a single stage four-bed adsorption chiller. However, the chiller works as a two stage four-bed adsorption chiller when the driving source temperature falls within the range from 40°C to 60°C. With a cooling water temperature of 30°C. It has been found that this dual mode adsorption chiller is capable to provide cooling throughout the year via measuring the coefficient of performance and the cooling capacity of the system.

  4. Cromatografia unificada Unified chromatography

    Directory of Open Access Journals (Sweden)

    Carin von Mühlen

    2004-10-01

    Full Text Available The scope of this study encompasses an overview of the principles of unified chromatography as well as the principles of chromatographic techniques as applied to unified systems, which include gas chromatography, liquid chromatography, supercritical fluid chromatography, high temperature and high pressure liquid chromatography, micro-liquid chromatography, enhanced fluidity chromatography, and solvating gas chromatography. Theoretical considerations and individual instrumental parameters such as mobile phase, sample introduction system, columns, and detection system are also discussed. Future applications of this separation approach are discussed.

  5. Effects of Cabin Upsets on Adsorption Columns for Air Revitalization

    Science.gov (United States)

    LeVan, Douglas

    1999-01-01

    The National Aeronautics and Space Administration (NASA) utilizes adsorption technology as part of contaminant removal systems designed for long term missions. A variety of trace contaminants can be effectively removed from gas streams by adsorption onto activated carbon. An activated carbon adsorption column meets NASA's requirements of a lightweight and efficient means of controlling trace contaminant levels aboard spacecraft and space stations. The activated carbon bed is part of the Trace Contaminant Control System (TCCS) which is utilized to purify the cabin atmosphere. TCCS designs oversize the adsorption columns to account for irregular fluctuations in cabin atmospheric conditions. Variations in the cabin atmosphere include changes in contaminant concentrations, temperature, and relative humidity. Excessively large deviations from typical conditions can result from unusual crew activity, equipment malfunctions, or even fires. The research carried out under this award focussed in detail on the effects of cabin upsets on the performance of activated carbon adsorption columns. Both experiments and modeling were performed with an emphasis on the roll of a change in relative humidity on adsorption of trace contaminants. A flow through fixed-bed apparatus was constructed at the NASA Ames Research Center, and experiments were performed there. Modeling work was performed at the University of Virginia.

  6. Bathing a patient in bed

    Science.gov (United States)

    Bed bath; Sponge bath ... Some patients cannot safely leave their beds to bathe. For these people, daily bed baths can help keep their skin healthy, control odor, and increase comfort. If moving the ...

  7. Interfacial adsorption of insulin - Conformational changes and reversibility of adsorption

    NARCIS (Netherlands)

    Mollmann, SH; Jorgensen, L; Bukrinsky, JT; Elofsson, U; Norde, W; Frokjaer, S

    2006-01-01

    The adsorption of human insulin to Teflon particles was studied with respect to conformational changes and the reversibility of adsorption was examined by total internal reflection fluorescence (TIRF). Adsorption isotherms for the adsorption of human insulin indicated high affinity adsorption, even

  8. Interfacial adsorption of insulin. Conformational changes and reversibility of adsorption

    NARCIS (Netherlands)

    Mollmann, S.H.; Bukrinsky, J.T.; Elofsson, U.; Norde, W.; Frokjaer, S.

    2006-01-01

    The adsorption of human insulin to Teflon particles was studied with respect to conformational changes and the reversibility of adsorption was examined by total internal reflection fluorescence (TIRF). Adsorption isotherms for the adsorption of human insulin indicated high affinity adsorption, even

  9. Structure optimization and performance experiments of a solar-powered finned-tube adsorption refrigeration system

    International Nuclear Information System (INIS)

    Highlights: • New-structure finned-tube adsorption bed for enhancing heat and mass transfer. • Temperatures on different parts of the adsorption tubes differ little. • Maximum COP of 0.122 and maximum daily ice-making of 6.5 kg are achieved by experiments. • Cooling efficiency of system with valve control higher than that without valve control. - Abstract: A large-diameter aluminum-alloy finned-tube absorbent bed collector was designed and optimized by enhancing the heat and mass transfer in the collector. The collection efficiency of the adsorbent bed collector was between 31.64% and 42.7%, and the temperature distribution in the absorbent bed was relatively uniform, beneficial to adsorption/desorption of the adsorbate in the absorbent bed. A solar-powered solid adsorption refrigeration system with the finned-tube absorbent bed collector was built. Some experiments corresponding to the adsorption/desorption process with and without a valve control were conducted in four typical weather conditions: sunny with clear sky, sunny with partly cloudy sky, cloudy sky and overcast sky. Activated carbon–methanol was utilized as the working pair for adsorption refrigeration in the experiments. The experiments achieved the maximum COP of 0.122 and the maximum daily ice-making of 6.5 kg. Under the weather conditions of sunny with clear sky, sunny with partly cloudy sky, and cloudy sky, ice-making phenomenon were observed. Even in the overcast-sky weather condition, the cooling efficiency of the system still reached 0.039 when the total solar radiation was 11.51 MJ. The cooling efficiency of the solar-powered adsorption refrigeration system with a valve control in the adsorption/desorption process was significantly higher than that without a valve control

  10. Tapered bed bioreactor

    Science.gov (United States)

    Scott, Charles D.; Hancher, Charles W.

    1977-01-01

    A vertically oriented conically shaped column is used as a fluidized bed bioreactor wherein biologically catalyzed reactions are conducted in a continuous manner. The column utilizes a packing material a support having attached thereto a biologically active catalytic material.

  11. Particle fuel bed tests

    International Nuclear Information System (INIS)

    Gas-cooled reactors, using packed beds of small diameter coated fuel particles have been proposed for compact, high-power systems. The particulate fuel used in the tests was 800 microns in diameter, consisting of a thoria kernel coated with 200 microns of pyrocarbon. Typically, the bed of fuel particles was contained in a ceramic cylinder with porous metallic frits at each end. A dc voltage was applied to the metallic frits and the resulting electric current heated the bed. Heat was removed by passing coolant (helium or hydrogen) through the bed. Candidate frit materials, rhenium, nickel, zirconium carbide, and zirconium oxide were unaffected, while tungsten and tungsten-rhenium lost weight and strength. Zirconium-carbide particles were tested at 2000 K in H2 for 12 hours with no visible reaction or weight loss

  12. Enuresis (Bed-Wetting)

    Science.gov (United States)

    ... get out of bed to go to the bathroom. When do most children achieve bladder control? Children ... ask questions about your child's daytime and nighttime bathroom habits. Then your doctor will do a physical ...

  13. Instrumentation: Ion Chromatography.

    Science.gov (United States)

    Fritz, James S.

    1987-01-01

    Discusses the importance of ion chromatography in separating and measuring anions. The principles of ion exchange are presented, along with some applications of ion chromatography in industry. Ion chromatography systems are described, as well as ion pair and ion exclusion chromatography, column packings, detectors, and programming. (TW)

  14. Adsorption de composés organiques volatils et régénération de charbons actifs - Developpement d'outils de simulation

    OpenAIRE

    Ramalingam, Shivaji Ganesan

    2012-01-01

    Organic vapors emitted from solvents used in chemical / food / pharmaceutical processes, or from hydrocarbon fuel storage stations at oil terminals, can be efficiently captured by adsorption onto activated carbon beds. The overall objective of the research program is the experimental and simulation studies of the adsorption and regeneration steps in the case of VOC removal which accounts into industrial emissions by Temperature Swing Adsorption (TSA) and Vacuum Temperature Swing Adsorption (V...

  15. Bed rest and immunity

    Science.gov (United States)

    Sonnenfeld, Gerald; Aviles, Hernan; Butel, Janet S.; Shearer, William T.; Niesel, David; Pandya, Utpal; Allen, Christopher; Ochs, Hans D.; Blancher, Antoine; Abbal, Michel

    2007-02-01

    Space flight has been shown to result in altered immune responses. The current study was designed to investigate this possibility by using the bed rest model of some space flight conditions. A large number of women are included as subjects in the study. The hypothesis being tested is: 60 days head-down tilt bed rest of humans will affect the immune system and resistance to infection. Blood, urine and saliva samples will be obtained from bed rest subjects prior to, at intervals during, and after completion of 60 days of head-down tilt bed rest. Leukocyte blastogenesis, cytokine production and virus reactivation will be assessed. The ability of the subjects to respond appropriately to immunization with the neoantigen bacteriophage φX-174 will also be determined. Bed rest is being carried out at MEDES, Toulouse France, and the University of Texas Medical Branch, Galveston, TX. The studies to be carried out in France will also allow assessment of the effects of muscle/bone exercise and nutritional countermeasures on the immune system in addition to the effects of bed rest.

  16. 用于乙醇脱水的生物质吸附性能%ADSORPTION CAPABILITY OF BIOMASS FOR ETHANOL DEHYDRATION

    Institute of Scientific and Technical Information of China (English)

    常华; 袁希钢; 曾爱武

    2004-01-01

    The adsorption capability of paddy flour and maize flour for gaseous phase selective adsorption for ethanol dehydration was investigated via a bench-test fixed-bed adsorber at constant temperature. Ethanol concentration in the feed was 93.4% (mass) and each of the dried biomass was used as adsorbent, and breakthrough curves and temperature distribution in adsorptive bed were obtained for different bed depths,superficial velocities, granularities of adsorbent and temperatures. Bed pressure drop curves for different bed depths and superficial velocities were also measured. A product of ethanol purity of 99.5% (mass) could be obtained through both kinds of biomass adsorbent. When 99.5% (mass) of ethanol purity is defined as the breakthrough point, the production capacity for either adsorbent was within 0.0915-0.2256 (gram product/gram adsorbent). Tests on pure ethanol adsorption were also performed to extrapolate the selectivity of both adsorbents.

  17. Operational strategy of adsorption desalination systems

    KAUST Repository

    Thu, Kyaw

    2009-03-01

    This paper presents the performances of an adsorption desalination (AD) system in two-bed and four-bed operational modes. The tested results are calculated in terms of key performance parameters namely, (i) specific daily water production (SDWP), (ii) cycle time, and (iii) performance ratio (PR) for various heat source temperatures, mass flow rates, cycle times along with a fixed heat sink temperature. The optimum input parameters such as driving heat source and cycle time of the AD cycle are also evaluated. It is found from the present experimental data that the maximum potable water production per tonne of adsorbent (silica gel) per day is about 10 m3 whilst the corresponding performance ratio is 0.61, and a longer cycle time is required to achieve maximum water production at lower heat source temperatures. This paper also provides a useful guideline for the operational strategy of the AD cycle. © 2008 Elsevier Ltd. All rights reserved.

  18. Structure sensitivity in adsorption

    DEFF Research Database (Denmark)

    Hammer, Bjørk; Nielsen, Ole Holm; Nørskov, Jens Kehlet

    1997-01-01

    The structure sensitivity of CO adsorption on different flat, stepped, kinked and reconstructed Pt surfaces is studied using large-scale density-functional calculations. We find an extremely strong structure sensitivity in the adsorption energy with variations up to 1 eV (or 100%) from one...

  19. A Simple Adsorption Experiment

    Science.gov (United States)

    Guirado, Gonzalo; Ayllon, Jose A.

    2011-01-01

    The study of adsorption phenomenon is one of the most relevant and traditional physical chemistry experiments performed by chemistry undergraduate students in laboratory courses. In this article, we describe an easy, inexpensive, and straightforward way to experimentally determine adsorption isotherms using pieces of filter paper as the adsorbent…

  20. Field demonstrations of radon adsorption units

    International Nuclear Information System (INIS)

    Four radon gas removal units have been installed in homes in the Northeast U.S. These units utilize dynamic adsorption of the radon gas onto activated charcoal to remove the radon from room air. Two beds of charcoal are used so that one bed removes radon while the second bed is regenerated using outdoor air in a unique process. The beds reverse at the end of a predetermined cycle time, providing continuous removal of radon from the room air. The process and units have undergone extensive development work in the laboratory as well as in homes and a summary of this work is discussed. This work showed that the system performs very effectively over a range of operating conditions similar to those found in a home. The field test data that is presented shows that scale up from the laboratory work was without problem and the units are functioning as expected. This unit provides homeowners and mitigation contractors with another option to solve the radon gas problem in homes, particularly in homes that it is difficult to prevent radon from entering

  1. The adsorption of nitrogen oxides on crystalline ice

    Directory of Open Access Journals (Sweden)

    T. Bartels

    2002-04-01

    Full Text Available The partitioning of nitrogen oxides between ice and air is of importance to the ozone budget in the upper troposphere. In the present study, adsorption of nitrogen oxides on ice was investigated at atmospheric pressure using a chromatographic technique with radioactively labelled nitrogen oxides at low concentrations. The measured retentions solely depended on molecular adsorption and were not influenced by dimerisation, formation of encapsulated hydrates on the ice surface, dissociation of the acids, nor by migration into a quasi-liquid layer or grain boundaries. Based on the chromatographic retention and the model of thermo-chromatography, the standard adsorption enthalpy of -20 kJ mol-1 for NO, -22kJ mol-1 for NO2, -30kJ mol-1 for peroxyacetyl nitrate, -32kJ mol-1 for HON} and -44 kJ mol-1 for HNO3 was calculated. To perform those calculations within the model of thermo-chromatography, the standard adsorption entropy was calculated based on statistical thermodynamics. In this work, two different choices of standard states were applied, and consequently different values of the standard adsorption entropy, of either between -39 kJ mol-1 and -45kJ mol-1, or -164 kJ mol-1 and -169 kJ mol-1 for each nitrogen oxide were derived. The standard adsorption enthalpy was identical for both standard adsorption entropies and thus shown to be independent of the choice of standard state. A brief outlook on environmental implications of our findings indicates that adsorption on ice might be an important removal process of HNO3. In addition, it might be of some importance for HONO and peroxyacetyl nitrate and irrelevant for NO and NO2.

  2. The adsorption of nitrogen oxides on crystalline ice

    Directory of Open Access Journals (Sweden)

    T. Bartels

    2002-01-01

    Full Text Available The partitioning of nitrogen oxides between ice and air is of importance to the ozone budget in the upper troposphere. In the present study, adsorption of nitrogen oxides on ice was investigated at atmospheric pressure using a chromatographic technique with radioactively labelled nitrogen oxides at low concentrations. The measured retentions solely depended on molecular adsorption and were not influenced by dimerisation, formation of encapsulated hydrates on the ice surface, dissociation of the acids, nor by migration into a quasi-liquid layer or grain boundaries. Based on the chromatographic retention and the model of thermo-chromatography, the standard adsorption enthalpy of -20 kJ mol-1 for NO, -22kJ mol-1 for NO2, -30kJ mol-1 for peroxyacetyl nitrate, -32kJ mol-1 for HON} and -44 kJ mol-1 for HNO3 was calculated. To perform those calculations within the model of thermo-chromatography, the standard adsorption entropy was calculated based on statistical thermodynamics. In this work, two different choices of standard states were applied, and consequently different values of the standard adsorption entropy, of either between -39 kJ mol-1 and -45kJ mol-1, or -164 kJ mol-1 and -169 kJ mol-1 for each nitrogen oxide were derived. The standard adsorption enthalpy was identical for both standard adsorption entropies and thus shown to be independent of the choice of standard state. A brief outlook on environmental implications of our findings indicates that adsorption on ice might be an important removal process of HNO3. In addition, it might be of some importance for HONO and peroxyacetyl nitrate and irrelevant for NO and NO2.

  3. Carbon nanotube based stationary phases for microchip chromatography

    DEFF Research Database (Denmark)

    Mogensen, Klaus Bo; Kutter, Jörg Peter

    2012-01-01

    The objective of this article is to provide an overview and critical evaluation of the use of carbon nanotubes and related carbon-based nanomaterials for microchip chromatography. The unique properties of carbon nanotubes, such as a very high surface area and intriguing adsorptive behaviour, have...

  4. Modeling of biopharmaceutical processes. Part 2: Process chromatography unit operation

    DEFF Research Database (Denmark)

    Kaltenbrunner, Oliver; McCue, Justin; Engel, Philip;

    2008-01-01

    Process modeling can be a useful tool to aid in process development, process optimization, and process scale-up. When modeling a chromatography process, one must first select the appropriate models that describe the mass transfer and adsorption that occurs within the porous adsorbent...

  5. Effect of DOM Size on Organic Micropollutant Adsorption by GAC.

    Science.gov (United States)

    Kennedy, Anthony M; Summers, R Scott

    2015-06-01

    Granular activated carbon (GAC) adsorption of the micropollutants 2-methylisoborneol (MIB) and warfarin (WFN) at ng/L levels was investigated in five waters with isolated natural dissolved organic matter (DOM) held at a constant dissolved organic carbon concentration. Each water was evaluated for competitive adsorption effects based on the pretreatment of ultrafiltration, coagulation, and additional background micropollutants. Using the breakthrough with unfractionated DOM as a baseline, on average, the water with lower molecular weight (MW) DOM decreased MIB and WFN adsorption capacity by 59%, whereas the water with higher MW DOM increased MIB and WFN adsorption capacity by 64%. All waters showed similar decreasing MIB and WFN adsorption capacity with increasing empty bed contact time (EBCT), with more dramatic effects seen for the more strongly adsorbing WFN. On average, MIB and WFN adsorption kinetics were two times slower in the water with higher MW DOM compared to the water with lower MW DOM, as described by the intraparticle pore diffusion tortuosity. Increased adsorption competition from 27 micropollutants other than MIB and WFN at environmentally relevant concentrations had little to no effect on MIB and WFN breakthrough behavior. Any competitive effect from background micropollutants became indiscernible at longer EBCTs. PMID:25955134

  6. Studies on lipase-affinity adsorption using response-surface analysis.

    Science.gov (United States)

    Kamimura, E S; Medieta, O; Rodrigues, M I; Maugeri, F

    2001-06-01

    Lipases are widely distributed enzymes that can be obtained from animals, plants and micro-organisms. Coupling lipases with a wide range of substrates allows the opportunity for synthesis of optically pure pharmaceutical preparations, flavour compounds and other food additives. Affinity chromatography owes its power as a purification method to specific biological interactions. Response-surface analysis was chosen to study column efficiency. This method allows the understanding of interactions between variables with advantages over conventional methods, which involve changing one variable while fixing others at certain levels. The aim of this work was to study the influence of the ratio bed height/column diameter (L/D) and superficial velocity (V) on the column efficiency. The experimental design involved the two variables, L/D (2-10) and v (1-2 cm/min), at five levels. Lipase was obtained from Geotrichum sp. culture in a complex medium composed of 5% corn-steep liquor, 0.5% NH(4)NO(3) and 1% olive oil at 30 degrees C, with 1VVM (air volume/medium volume per min) aeration and 400 rev./min agitation. Maximum lipase activity was 19 units/ml after almost 9 h of fermentation. This lipase could potentially be used in esterification reactions to increase the content of gamma-linolenic acid and to produce bioaromas for food industries. The adsorption assays were carried out in a fixed-bed column with an affinity adsorbent, which was obtained by reaction of a gel with oleic acid as ligand. Breakthrough curves were obtained for all experiments. It has been shown that the lower the values of both L/D and v, the higher the column efficiency (maximum 65.43%). Also, it was observed from the response surface that the efficiency reached a minimum at an L/D of around 8.

  7. Bed bug deterrence

    Directory of Open Access Journals (Sweden)

    Haynes Kenneth F

    2010-09-01

    Full Text Available Abstract A recent study in BMC Biology has determined that the immature stage of the bed bug (the nymph signals its reproductive status to adult males using pheromones and thus avoids the trauma associated with copulation in this species. The success of this nymphal strategy of deterrence is instructive. Against the background of increasing problems with bed bugs, this research raises the question whether pheromones might be used to control them. See research article http://www.biomedcentral.com/1741-7007/8/121

  8. Competitive Protein Adsorption - Multilayer Adsorption and Surface Induced Protein Aggregation

    DEFF Research Database (Denmark)

    Holmberg, Maria; Hou, Xiaolin

    2009-01-01

    In this study, competitive adsorption of albumin and IgG (immunoglobulin G) from human serum solutions and protein mixtures onto polymer surfaces is studied by means of radioactive labeling. By using two different radiolabels (125I and 131I), albumin and IgG adsorption to polymer surfaces...... is monitored simultaneously and the influence from the presence of other human serum proteins on albumin and IgG adsorption, as well as their mutual influence during adsorption processes, is investigated. Exploring protein adsorption by combining analysis of competitive adsorption from complex solutions...... of high concentration with investigation of single protein adsorption and interdependent adsorption between two specific proteins enables us to map protein adsorption sequences during competitive protein adsorption. Our study shows that proteins can adsorb in a multilayer fashion onto the polymer surfaces...

  9. Properties of Spent Active Coke Particles Analysed via Comminution in Spouted Bed

    OpenAIRE

    Bronislaw Buczek

    2013-01-01

    Samples of active coke, fresh and spent after cleaning flue gases from communal waste incinerators, were investigated. The outer layers of both coke particles were separately removed by comminution in a spouted bed. The samples of both active cokes were analysed by means of densities, mercury porosimetry, and adsorption technique. Remaining cores were examined to determine the degree of consumption of coke by the sorption of hazardous emissions (SO2, HCl, and heavy metals) through its bed. Di...

  10. Adsorption of phenol and chlorophenols on pure and modified sepiolite

    Directory of Open Access Journals (Sweden)

    A. YILDIZ

    2007-05-01

    Full Text Available In this work, pure sepiolite and sepiolite modified by nitric acid (HNO3, ethylenediaminetetraacetic acid (EDTA and hexadecyltrimethyl-ammonium (HDTMA were used ad adsorbents. The changes on the surface were studied by IR spectroscopy. The adsorption of solutions of phenol and phenol derivatives in pure ethanol on these adsorbents were examined by means of gas chromatography. It was found that the adsorption capacities of the clay–organic complexes (sepiolite–EDTA and sepiolite–HDTMA were higher than those of pure sepiolite and sepiolite–HNO3.

  11. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T.; Sahimi, Muhammad; Fayyaz-Najafi, Babak; Harale, Aadesh; Park, Byoung-Gi; Liu, Paul K. T.

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  12. Hybrid adsorptive membrane reactor

    Science.gov (United States)

    Tsotsis, Theodore T. (Inventor); Sahimi, Muhammad (Inventor); Fayyaz-Najafi, Babak (Inventor); Harale, Aadesh (Inventor); Park, Byoung-Gi (Inventor); Liu, Paul K. T. (Inventor)

    2011-01-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  13. High Performance Cascading Adsorption Refrigeration Cycle with Internal Heat Recovery Driven by a Low Grade Heat Source Temperature

    OpenAIRE

    Yuki Ueda; Atsushi Akisawa; Aep Saepul Uyun; Takahiko Miyazaki

    2009-01-01

    This paper presents the performance of an advanced cascading adsorption cycle that utilizes a driven heat source temperature between 90–130 ºC. The cycle consists of four beds that contain silica gel as an adsorber fill. Two of the beds work in a single stage cycle that is driven by an external heat source, while the other two beds work in a mass recovery cycle that is driven by waste heat of sensible and adsorption heat of the high temperature cycle. The performances, in terms of the coef...

  14. Adsorption behaviour of bulgur.

    Science.gov (United States)

    Erbaş, Mustafa; Aykın, Elif; Arslan, Sultan; Durak, Atike N

    2016-03-15

    The aim of this research was to determine the adsorption behaviour of bulgur. Three different particle sizes (2dry matter and 4.96-16.57, respectively. Constant k was between 0.85 and 0.93, and GAB equation was determined to fit very well for bulgur adsorption, because of %E values lower than 10%. Bulgur must be stored below 70% relative humidity and with less than 10 g water per 100 g of dry mater. PMID:26575716

  15. Maximum spoutable bed height of spout-fluid bed

    Energy Technology Data Exchange (ETDEWEB)

    Wenqi Zhong; Mingyao Zhang; Baosheng Jin [Southeast University, Nanjing (China). Key Laboratory on Clean Coal Power Generation and Combustion Technology of Ministry of Education

    2006-11-15

    Experimental study on the maximum spoutable bed height of a spout-fluid bed (cross-section of 0.3 m x 0.03 m and height of 2 m) packed with Geldart group D particles has been carried out. The effects of particle size, spout nozzle size and fluidizing gas flow rate on the maximum spoutable bed height were studied. Experimental data were compared to some published experiments and predictions. The results show that the maximum spoutable bed height of spout-fluid bed decreases with increasing particle size and spout nozzle size, which appears the same trend to that of spouted beds. The increasing of fluidizing gas flow rate leads to a sharply decrease in the maximum spoutable bed height. The existent correlations of the maximum spoutable bed height in the literature were observed to involve large discrepancies. Additionally, the flow characteristics when bed materials deeper than the maximum spoutable height were summarized. Under this condition, the spout-fluid bed operated without a stable and coherent spout or fountain assembles the characteristics of jetting fluidized bed. Besides, the mechanisms of spout termination were investigated. It was found that slugging in the spout and growth of instabilities would cause the spout termination in spout-fluid bed.

  16. Assessing the adsorption properties of shales

    Science.gov (United States)

    Pini, Ronny

    2015-04-01

    Physical adsorption refers to the trapping of fluid molecules at near liquid-like densities in the pores of a given adsorbent material. Fine-grained rocks, such as shales, contain a significant amount of nanopores that can significantly contribute to their storage capacity. As a matter of fact, the current ability to extract natural gas that is adsorbed in the rock's matrix is limited, and current technology focuses primarily on the free gas in the fractures (either natural or stimulated), thus leading to recovery efficiencies that are very low. Shales constitute also a great portion of so-called cap-rocks above potential CO2 sequestration sites; hereby, the adsorption process may limit the CO2 mobility within the cap-rock, thus minimizing the impact of leakage on the whole operation. Whether it is an unconventional reservoir or a cap-rock, understanding and quantifying the mechanisms of adsorption in these natural materials is key to improve the engineering design of subsurface operations. Results will be presented from a laboratory study that combines conventional techniques for the measurement of adsorption isotherms with novel methods that allows for the imaging of adsorption using x-rays. Various nanoporous materials are considered, thus including rocks, such as shales and coals, pure clay minerals (a major component in mudrocks) and engineered adsorbents with well-defined nanopore structures, such as zeolites. Supercritical CO2 adsorption isotherms have been measured with a Rubotherm Magnetic Suspension balance by covering the pressure range 0.1-20~MPa. A medical x-ray CT scanner has been used to identify three-dimensional patterns of the adsorption properties of a packed-bed of adsorbent, thus enabling to assess the spatial variability of the adsorption isotherm in heterogeneous materials. The data are analyzed by using thermodynamically rigorous measures of adsorption, such as the net- and excess adsorbed amounts and a recently developed methodology is

  17. Getting Rid of Bed Bugs

    Science.gov (United States)

    ... how you select a company. Related Information Collaborative Strategy on Bed Bugs - highlights ways that all levels of government, community, academia and private industry can work together to reduce bed bugs across ...

  18. Equilibrium adsorption data from temperature-programmed desorption experiments

    OpenAIRE

    Foeth, Frank; Mugge, José; Vaart, van der, A.W.; Bosch, Hans; Reith, Tom

    1996-01-01

    This work describes a novel method that enables the calculation of a series of adsorption isotherms basically from a single Temperature-Programmed Desorption (TPD) experiment. The basic idea is to saturate an adsorbent packed in a fixed bed at a certain feed concentration and temperature and to subsequently increase its temperature linearly with time, while maintaining a constant feed concentration. We measured TPD response curves for carbon dioxide on activated carbon at different heating ra...

  19. Performance Prediction of Solar Adsorption Refrigeration System by Ann

    OpenAIRE

    Baiju, V.; C. Muraleedharan

    2012-01-01

    This paper proposes a new approach for the performance analysis of a single-stage solar adsorption refrigeration system with activated carbon-R134a as working pair. Use of artificial neural network has been proposed to determine the performance parameters of the system, namely, coefficient of performance, specific cooling power, adsorbent bed (thermal compressor) discharge temperature, and solar cooling coefficient of performance. The ANN used in the performance prediction was made in MATLAB ...

  20. Simulation of adsorption processes in gas cleanup filters

    Energy Technology Data Exchange (ETDEWEB)

    Hrdlicka, F.; Slavik, P.; Kubelka, O.

    2001-07-01

    The problem of cleaning gas obtained by coal gasification is discussed. Realisation of this process takes the form of filters with various properties. The efficiency of the gas cleaning process can be influenced by several factors. One class of factors is the physical properties of the granules used in the filter. These properties influence the way the granules move in the filter bed. Another class of problems concerns the adsorption properties of the granules. The quality of adsorption influences the efficiency of a filter and thus the costs of the gas cleaning process. The optimal combination of adsorption and physical properties of granules leads to the optimal exploitation of the filter, both from the point of view of costs and the degree of gas cleaning. While the physical properties of granules have been investigated, the adsorption properties still remain an unknown factor (or at least a factor with an unknown impact on the filter efficiency) from the point of view of filter design and exploitation. The main goal of the research was to investigate and simulate the adsorption capability of granules. The expected result was the determination of optimal counterplay between physical and adsorption processes. A simulation model with visualisation module has been developed and implemented. 5 refs., 5 figs.

  1. Exploring Fluorous Affinity by Liquid Chromatography.

    Science.gov (United States)

    Catani, Martina; Guzzinati, Roberta; Marchetti, Nicola; Pasti, Luisa; Cavazzini, Alberto

    2015-07-01

    Terms such as "fluorous affinity" and "fluorophilicity" have been used to describe the unique partition and sorption properties often exhibited by highly fluorinated organic compounds, that is molecules rich in sp(3) carbon-fluorine bonds. In this work, we made use of a highly fluorinated stationary phase and a series of benzene derivatives to study the effect of one single perfluorinated carbon on the chromatographic behavior and adsorption properties of molecules. For this purpose, the adsorption equilibria of α,α,α-trifluorotoluene, toluene, and other alkylbenzenes have been studied by means of nonlinear chromatography in a variety of acetonitrile/water eluents. Our results reveal that one single perfluorinated carbon is already enough to induce a drastic change in the adsorption properties of molecules on the perfluorinated stationary phase. In particular, it has been found that adsorption is monolayer if the perfluoroalkyl carbon is present but that, when this unit is missing, molecules arrange as multilayer stack structures. These findings can contribute to the understanding of molecular mechanisms of fluorous affinity. PMID:26047527

  2. Purification of a recombinant baculovirus of Autographa californica M nucleopolyhedrovirus by ion exchange membrane chromatography.

    Science.gov (United States)

    Grein, Tanja A; Michalsky, Ronald; Vega López, Maria; Czermak, Peter

    2012-08-01

    Significant progress in the application of viral vectors for gene delivery into mammalian cells and the use of viruses as biopesticides requires downstream processing that can satisfy application-specific demands on performance. In the present work the stability and ion exchange membrane chromatography of a recombinant of Autographa californica M nucleopolyhedrovirus is studied. To adjust the degree of purification the effect of ionic conductivity or pH on the viral infectivity was assessed (0.77-78.00mS/cm, pH 3-8). Infectivity decreased rapidly by several orders of magnitude at below 5mS/cm (i.e., 0.49MPa osmotic pressure change) or at below pH 5.5 (rationalized with particle aggregation). The virus was concentrated and purified via adsorption (0.2-1.1×10(16)pfu/m(3) chromatographic bed volume, 0.6-1.1×10(12)pfu/m(2) membrane area facing the incident fluid flow) and elution at pH 6.1 and 6.35mS/cm from three strong anion exchange membranes. Virus recovery and concentration in accord with the volume reduction were obtained using a polyether sulfone-based membrane with quaternary ammonium ligands. The level of host cell protein (down to below the detection limit) and suspended DNA (below 93pg DNA per 10(6)pfu) are reported for each membrane employed, for the purpose of comparability, under equal adsorption or elution conditions respectively.

  3. Effect of the switching time on the performance of an adsorption chiller

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sang Woo; Chung, Jae Dong [Sejong University, Seoul (Korea, Republic of); Kwon, Oh Kyung [Korea Institute of Industrial Technology, Chonan (Korea, Republic of)

    2016-05-15

    The switching time is an important operating condition that must be correctly anticipated for an effective adsorption cooling system. Before the adsorption (or desorption) process begins, time is required to cool down (or heat up) the bed temperature so that the bed pressure reaches the evaporator pressure (or condenser pressure). During the switching time, the supplied heat is reduced and pressure overload conditions can be avoided. The switching time cannot be estimated early on, and an improper switching time degrades the system performance. Thus, this study provides guideline with which to determine the required time to open this valve, i.e., the switching time, and carefully examines the thermo-physical behavior in the adsorption bed during this period. A two-dimensional numerical method with the composite sorbent of SWS-1L and a water pair is applied to a fin-tube type adsorption chiller. Three cases of no switching time, the optimal switching time and a double the optimal switching time are examined. The results show that no consideration of the switching time overestimates the performance of the adsorption cooling system in terms of the Coefficient of performance (COP) and the Specific cooling power (SCP). On the other hand, if the switching time exceeds the optimal value, the performance of the adsorption cooling system is also reduced compared to that when using the optimal switching time. The dependency of the optimal switching times on various design parameters, such as the fin pitch, fin height and heating temperature, is also examined.

  4. Adsorptive Removal of Para-chlorophenol Using Stratified Tapered Activated Carbon Column

    Institute of Scientific and Technical Information of China (English)

    M.EE Sze; G. McKay

    2012-01-01

    The feasibility of adsorptive removal of single component organic compound (para-chlorophenol) by Calgon Filtrasorb 400 (F400) carbon was investigated. The Redlich-Peterson equation was found to be the best fit model for describing the equilibrium relationship between the para-chlorophenol adsorption onto F400 carbon. Four adsorption columns with different column geometry and adsorbent particle stratification were used to examine the adsorption kinetics onto F400 carbons. The Bed Depth Service Time (BDST) model was applied and modified to analyse the performance of the columns and the effect of different operating variables. When combining the effects of adsorption efficiency and the associated pressure drop of each type of adsorption columns tested, the carbon stratified tapered column has been determined to be the most efficient engineering option for removing organics, in which the enhancement of the adsorbent bed in terms of longer breakthrough time and higher saturation percentage is the greatest amongst the four types of columns with reasonably small pressure drop across the fixed-bed column.

  5. Performance Analysis of Waste Heat Driven Pressurized Adsorption Chiller

    KAUST Repository

    LOH, Wai Soong

    2010-01-01

    This article presents the transient modeling and performance of waste heat driven pressurized adsorption chillers for refrigeration at subzero applications. This innovative adsorption chiller employs pitch-based activated carbon of type Maxsorb III (adsorbent) with refrigerant R134a as the adsorbent-adsorbate pair. It consists of an evaporator, a condenser and two adsorber/desorber beds, and it utilizes a low-grade heat source to power the batch-operated cycle. The ranges of heat source temperatures are between 55 to 90°C whilst the cooling water temperature needed to reject heat is at 30°C. A parametric analysis is presented in the study where the effects of inlet temperature, adsorption/desorption cycle time and switching time on the system performance are reported in terms of cooling capacity and coefficient of performance. © 2010 by JSME.

  6. Geomechanics of bedded salt

    Energy Technology Data Exchange (ETDEWEB)

    Serata, S.; Milnor, S.W.

    1979-06-08

    Creep data from the literature search is reinterpreted by SGI, resulting in a better understanding of the temperature and stress state dependence of the octahedral creep rate and the octahedral shear strength. The concept of a transition strength between the elastic and the plastic states is in agreement with the data. The elastic and rheological properties of salt are described, and a set of constitutive equations is presented. The dependence of material properties on parameters such as temperature is considered. Findings on the permeability of salt are summarized, and the in-situ behavior of openings in bedded salt is described based on extensive engineering experience. A stress measuring system utilizing a finite element computer code is discussed. Geological factors affecting the stability of salt openings are considered, and the Stress Control Technique for designing stable openings in bedded salt formations is explained.

  7. Geomechanics of bedded salt

    International Nuclear Information System (INIS)

    Creep data from the literature search is reinterpreted by SGI, resulting in a better understanding of the temperature and stress state dependence of the octahedral creep rate and the octahedral shear strength. The concept of a transition strength between the elastic and the plastic states is in agreement with the data. The elastic and rheological properties of salt are described, and a set of constitutive equations is presented. The dependence of material properties on parameters such as temperature is considered. Findings on the permeability of salt are summarized, and the in-situ behavior of openings in bedded salt is described based on extensive engineering experience. A stress measuring system utilizing a finite element computer code is discussed. Geological factors affecting the stability of salt openings are considered, and the Stress Control Technique for designing stable openings in bedded salt formations is explained

  8. Adsorption onto fibrous activated carbon: applications to water treatment

    Energy Technology Data Exchange (ETDEWEB)

    Le Cloirec, P.; Brasquet, C.; Subrenat, E. [Ecole des Mines de Nantes, Nantes (France)

    1997-03-01

    The adsorption of polluted waters is performed by activated carbon fibers (ACF). This new material is characterized by scanning electron microscopy. BET surface areas and pore volumes are determined. Adsorption of natural organics (humic substances) and micropollutants (aromatic compounds such as benzene and toluene) is carried out in a batch or dynamic reactor. Classical models are applied and kinetic constants calculated. The results show that the performance of ACF is significantly higher than that of granular activated carbon (GAC) in terms of adsorption velocity and selectivity for micropollutants. These higher performances are due to some ACF physical properties, such as their high BET surface area and micropore volume. Moreover, the micropores are directly connected on the external surface area of fibers, which allows smaller mass transfer resistance. In a dynamic reactor, the breakthrough curves obtained with ACF beds are particularly steep, suggesting a smaller mass transfer resistance than that of GAC. The adsorption zone in an ACF bed is about 3.5 mm and is not really dependent on the water flow rate within the studied range. 25 refs., 14 figs., 6 tabs.

  9. Improved Thermal Modulator for Gas Chromatography

    Science.gov (United States)

    Hasselbrink, Ernest Frederick, Jr.; Hunt, Patrick J.; Sacks, Richard D.

    2008-01-01

    An improved thermal modulator has been invented for use in a variant of gas chromatography (GC). The variant in question denoted as two-dimensional gas chromatography (2DGC) or GC-GC involves the use of three series-connected chromatographic columns, in the form of capillary tubes coated interiorly with suitable stationary phases (compounds for which different analytes exhibit different degrees of affinity). The two end columns are relatively long and are used as standard GC columns. The thermal modulator includes the middle column, which is relatively short and is not used as a standard GC column: instead, its temperature is modulated to affect timed adsorption and desorption of analyte gases between the two end columns in accordance with a 2DGC protocol.

  10. 大型蛋白质色谱柱及凝胶介质的综述%The Development of Gel Media and Columns for Large-Scale Chromatography of Proteins, a Historical Review

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The first dedicated protein chromatography media were introduced during the 1950s and 1960s. There was an early awareness of the possibility of using these for production applications within the biopharmaceutical industry. However, the crucial limitation was the fact that those media that were most compatible with proteins lent themselves less favourably to scaling-up. The problems were primarily physical. Thus the fibrous cellulose media showed bed cracking tendencies and the bead shaped polyacrylamide, dextran, and agarose gel media, then available,were too soft to stand the hydrodynamic forces acting in large columns, leading to bed compaction and increased pressure drop. At the time, the best solution to the latter problem, after a number of intermediary solutions were tried, was the introduction of the stacked column concept in which several short column segments were connected by small bore tubing, thus reducing the force acting on the particles in each bed compartment. However, the ultimate remedy, the introduction of chromatographic matrices that combine the desired features of adequate rigidity,macroporosity, biocompatibility, chemical stability (for CIP and SIP) and derivatizability, did not occur until the middle of the 1980s when adequately cross-linked agarose gel media such as Sepharose(R) Fast Flow were made available. The paper also recognizes the many attempts made during the past 50 years to develop continous chromatography columns. Most of the designs are based on an annular bed or on an array of annularly arranged parallel columns continuously fed with samples in a cyclic manner. The introduction of media and columns for expanded bed adsorption followed a demand for fewer purification steps and shorter process times. In recent years, columns have been introduced that allow packing and repacking without needing to open the column. The review provides an historical account of the developments that have led to the present state-of-the-art both

  11. Breakthrough CO₂ adsorption in bio-based activated carbons.

    Science.gov (United States)

    Shahkarami, Sepideh; Azargohar, Ramin; Dalai, Ajay K; Soltan, Jafar

    2015-08-01

    In this work, the effects of different methods of activation on CO2 adsorption performance of activated carbon were studied. Activated carbons were prepared from biochar, obtained from fast pyrolysis of white wood, using three different activation methods of steam activation, CO2 activation and Potassium hydroxide (KOH) activation. CO2 adsorption behavior of the produced activated carbons was studied in a fixed-bed reactor set-up at atmospheric pressure, temperature range of 25-65°C and inlet CO2 concentration range of 10-30 mol% in He to determine the effects of the surface area, porosity and surface chemistry on adsorption capacity of the samples. Characterization of the micropore and mesopore texture was carried out using N2 and CO2 adsorption at 77 and 273 K, respectively. Central composite design was used to evaluate the combined effects of temperature and concentration of CO2 on the adsorption behavior of the adsorbents. The KOH activated carbon with a total micropore volume of 0.62 cm(3)/g and surface area of 1400 m(2)/g had the highest CO2 adsorption capacity of 1.8 mol/kg due to its microporous structure and high surface area under the optimized experimental conditions of 30 mol% CO2 and 25°C. The performance of the adsorbents in multi-cyclic adsorption process was also assessed and the adsorption capacity of KOH and CO2 activated carbons remained remarkably stable after 50 cycles with low temperature (160°C) regeneration. PMID:26257348

  12. The effect of mass recovery adsorption cooling cycle to optimize the collector number and time allocation

    Science.gov (United States)

    Kabir, K. M. Ariful; Alam, K. C. Amanul; Rouf, Rifat A.; Sarker, M. M. A.

    2016-07-01

    The performance of mass recovery for solar adsorption cooling system has been investigated numerically. Solar adsorption cooling appears to have a prospect in tropical region. Though it has a huge installation cost, its long term payback could be a considerable fact. Mass recovery scheme increases Average Cooling Capacity (ACC) and Coefficient of Performance (COP) values of the adsorption cooling system. In intension to reduce cost and maximize system performance, a two bed solar driven conventional cooling system run by silica gel and water along with mass recovery process has been investigated mathematically.

  13. Pulse gas chromatographic study of adsorption of substituted aromatics and heterocyclic molecules on MIL-47 at zero coverage.

    Science.gov (United States)

    Duerinck, Tim; Couck, Sarah; Vermoortele, Frederik; De Vos, Dirk E; Baron, Gino V; Denayer, Joeri F M

    2012-10-01

    The low coverage adsorptive properties of the MIL-47 metal organic framework toward aromatic and heterocyclic molecules are reported in this paper. The effect of molecular functionality and size on Henry adsorption constants and adsorption enthalpies of alkyl and heteroatom functionalized benzene derivates and heterocyclic molecules was studied using pulse gas chromatography. By means of statistical analysis, experimental data was analyzed and modeled using principal component analysis and partial least-squares regression. Structure-property relationships were established, revealing and confirming several trends. Among the molecular properties governing the adsorption process, vapor pressure, mean polarizability, and dipole moment play a determining role. PMID:22958218

  14. Chromatography resin support

    Science.gov (United States)

    Dobos, James G.

    2002-01-01

    An apparatus and method of using an improved chromatography resin support is disclosed. The chromatography support platform is provided by a stainless steel hollow cylinder adapted for being inserted into a chromatography column. An exterior wall of the stainless steel cylinder defines a groove for carrying therein an "O"-ring. The upper surface of the stainless steel column is covered by a fine stainless steel mesh welded to the edges of the stainless steel cylinder. When placed upon a receiving ledge defined within a chromatography column, the "O"-ring provides a fluid tight seal with the inner edge wall of the chromatography cylinder. The stainless steel mesh supports the chromatography matrix and provides a back flushable support which is economical and simple to construct.

  15. Determination of the rodenticide difenacoum in biological materials by high-pressure liquid chromatography with confirmation of identity by mass spectrometry.

    Science.gov (United States)

    Mundy, D E; Machin, A F

    1977-09-21

    A method for determining difenacoum in liver, plasma, urine and feedingstuffs by high-pressure liquid chromatography is described. Samples are cleaned up by molecular exclusion chromatography on porous glass. In some cases this also serves for determination; if not, the separated difenacoum is determined on an adsorption column. Identity is confirmed by chemical ionisation mass spectrometry. Recoveries at levels of 0.025-5 ppm from plasma were 101-113% by exclusion chromatography alone and 93-101% after adsorption chromatography. Recoveries from liver after both chromatographic steps were 62-86%. Reasons for the lower recoveries from liver are suggested. PMID:893620

  16. Bed Rest Muscular Atrophy

    Science.gov (United States)

    Greenleaf, John E.

    2000-01-01

    A major debilitating response from prolonged bed rest (BR) is muscle atrophy, defined as a "decrease in size of a part of tissue after full development has been attained: a wasting away of tissue as from disuse, old age, injury or disease". Part of the complicated mechanism for the dizziness, increased body instability, and exaggerated gait in patients who arise immediately after BR may be a result of not only foot pain, but also of muscular atrophy and associated reduction in lower limb strength. Also, there seems to be a close association between muscle atrophy and bone atrophy. A discussion of many facets of the total BR homeostatic syndrome has been published. The old adage that use determines form which promotes function of bone (Wolff's law) also applies to those people exposed to prolonged BR (without exercise training) in whom muscle atrophy is a consistent finding. An extreme case involved a 16-year-old boy who was ordered to bed by his mother in 1932: after 50 years in bed he had "a lily-white frame with limbs as thin as the legs of a ladder-back chair". These findings emphasize the close relationship between muscle atrophy and bone atrophy. In addition to loss of muscle mass during deconditioning, there is a significant loss of muscle strength and a decrease in protein synthesis. Because the decreases in force (strength) are proportionately greater than those in fiber size or muscle cross-sectional area, other contributory factors must be involved; muscle fiber dehydration may be important.

  17. Coal Bed Methane Primer

    Energy Technology Data Exchange (ETDEWEB)

    Dan Arthur; Bruce Langhus; Jon Seekins

    2005-05-25

    During the second half of the 1990's Coal Bed Methane (CBM) production increased dramatically nationwide to represent a significant new source of income and natural gas for many independent and established producers. Matching these soaring production rates during this period was a heightened public awareness of environmental concerns. These concerns left unexplained and under-addressed have created a significant growth in public involvement generating literally thousands of unfocused project comments for various regional NEPA efforts resulting in the delayed development of public and fee lands. The accelerating interest in CBM development coupled to the growth in public involvement has prompted the conceptualization of this project for the development of a CBM Primer. The Primer is designed to serve as a summary document, which introduces and encapsulates information pertinent to the development of Coal Bed Methane (CBM), including focused discussions of coal deposits, methane as a natural formed gas, split mineral estates, development techniques, operational issues, producing methods, applicable regulatory frameworks, land and resource management, mitigation measures, preparation of project plans, data availability, Indian Trust issues and relevant environmental technologies. An important aspect of gaining access to federal, state, tribal, or fee lands involves education of a broad array of stakeholders, including land and mineral owners, regulators, conservationists, tribal governments, special interest groups, and numerous others that could be impacted by the development of coal bed methane. Perhaps the most crucial aspect of successfully developing CBM resources is stakeholder education. Currently, an inconsistent picture of CBM exists. There is a significant lack of understanding on the parts of nearly all stakeholders, including industry, government, special interest groups, and land owners. It is envisioned the Primer would being used by a variety of

  18. An Investigative and Concise Review on Evaporation and Condensation Processes Using Vapour Adsorption Technique

    Directory of Open Access Journals (Sweden)

    Dim Dim Kumar

    2014-10-01

    Full Text Available The vapour adsorption refrigeration is based on the evaporation and condensation of a refrigerant combined with adsorption or chemical reaction. The towering fossil fuel price and the responsiveness of environmental problems offer many potential applications to thermal powered adsorption cooling. However, the adsorption cooling machines still have some disadvantages that hinder their wide application. The patents surveyed are classified into four main groups: adsorption system development, adsorbent bed innovation, adsorbent/adsorbate material development and novel application of adsorption cooling system. The adsorption refrigeration is based on the evaporation and condensation of a refrigerant combined with adsorption or chemical reaction. Important targets are to reach a high efficiency through optimization measures at various components and the control system. On the other hand measures are to verify to simplify the construction with regard to a low-cost manufacturing, as well as to reach long periods with maintenance-free operation. This review paper gives a comprehensive review on the work carried out on vapour adsorption refrigeration for cryogenic applications.

  19. Off-gas adsorption model and simulation - OSPREY

    International Nuclear Information System (INIS)

    A capability of accurately simulating the dynamic behavior of advanced fuel cycle separation processes is expected to provide substantial cost savings and many technical benefits. To support this capability, a modeling effort focused on the off-gas treatment system of a used nuclear fuel recycling facility is in progress. The off-gas separation consists of a series of scrubbers and adsorption beds to capture constituents of interest. Dynamic models are being developed to simulate each unit operation involved so each unit operation can be used as a stand-alone model and in series with multiple others. Currently, an adsorption model has been developed within Multi-physics Object Oriented Simulation Environment (MOOSE) developed at the Idaho National Laboratory (INL). Off-gas Separation and Recovery (OSPREY) models the adsorption of offgas constituents for dispersed plug flow in a packed bed under non-isothermal and non-isobaric conditions. Inputs to the model include gas composition, sorbent and column properties, equilibrium and kinetic data, and inlet conditions. The simulation outputs component concentrations along the column length as a function of time from which breakthrough data can be obtained. The breakthrough data can be used to determine bed capacity, which in turn can be used to size columns. In addition to concentration data, the model predicts temperature along the column length as a function of time and pressure drop along the column length. A description of the OSPREY model, results from krypton adsorption modeling and plans for modeling the behavior of iodine, xenon, and tritium will be discussed. (author)

  20. Characteristics of isothermal adsorption and desorption of aluminum ion to/from humic acids

    Institute of Scientific and Technical Information of China (English)

    WANG Qiang; WEI Shiqiang; HUANG Yuming; ZHANG Jinzhong

    2008-01-01

    The adsorption and desorption characteristics of Al3+ to/from humic acids at different pH, ionic strength, and temperature were studied by the C-25 glucosan-gel chromatography method. The results showed that the maximum adsorption amount (Qmax) and adsorption constant (k) increased, whereas, the absolute value of standard thermodynamic molar free energy change (AG0. m) decreased with the increase of pH at constant ionic strength and temperature. With ionic strength increasing from 0 to 0. 15 mol/L, Qmax and k increased and the absolute value of AG0. m decreased at constant pH and temperature. High temperature was unfavorable for the adsorption reaction, as indicated by the dramatic decrease of Qmax and the absolute value of AG0. m with an increase in temperature. The standard thermodynamic molar free energy change (AG0. m) and the standard thermodynamic enthalpy change (AH0. m) of the adsorption reaction were both negative, suggesting that adsorption reaction was spontaneous and exothermic. The desorption rate of HA-AI3+ complex accelerated with the decrease of pH, and a significant linear relationship could be obtained between pH and the desorption rates of Al3+ from humic acids. These results demonstrated that the Al3+ adsorption reaction was a "biphase" reaction, and adsorption occurred at both the interior and exterior adsorption sites of humic acids.

  1. Carbonaceous materials for adsorptive refrigerators

    Science.gov (United States)

    Buczek, B.; Wolak, E.

    2012-06-01

    Carbon monoliths prepared from hard coal precursors were obtained. The porous structure of the monoliths was evaluated on the basis of nitrogen adsorption — desorption equilibrium data. The investigated monoliths have a well-developed microporous structure with significant specific surface area (S BET ). Equilibrium studies of methanol vapour adsorption were used to characterize the methanol adsorptive capacity that was determined using a volumetric method. The heat of wetting by methanol was determined in order to estimate the energetic effects of the adsorption process. The results of the investigations show that all monoliths exhibit high adsorption capacity and high heat of wetting with methanol.

  2. Mass transfer mechanism in chiral reversed phase liquid chromatography.

    Science.gov (United States)

    Gritti, Fabrice; Guiochon, Georges

    2014-03-01

    The mechanism of mass transfer in chiral chromatography was investigated using an experimental protocol already applied in RPLC and HILIC chromatography. The different contributions to the reduced height equivalent to a theoretical plate (HETP) include the longitudinal diffusion HETP term, the solid-liquid mass transfer resistance HETP term, the short-range eddy dispersion HETP term, and the long-range eddy dispersion HETP term. Their accurate measurement permits the determination of the adsorption rate constant kads of trans-stilbene enantiomers on a column packed with Lux 5 μm Cellulose-1 particles. The experimental results demonstrate that the number of adsorption-desorption steps per unit time of chiral compounds on polysaccharide-based chiral stationary phases is four orders of magnitude smaller than that of achiral compounds.

  3. Dynamic measurement of mercury adsorption and oxidation on activated carbon in simulated cement kiln flue gas

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Anker Degn; Windelin, Christian;

    2012-01-01

    of the sulfite converter is short and typically within 2min. Dynamic mercury adsorption and oxidation tests on commercial activated carbons Darco Hg and HOK standard were performed at 150°C using simulated cement kiln gas and a fixed bed reactor system. It is shown that the converter and analyzer system...

  4. Characterisation of the surface of a cellulosic multi-purpose office paper by inverse gas chromatography

    OpenAIRE

    Santos, J.M.R.C.A.; Gil, M. H.; Portugal, A. (A.); Guthrie, J. T.

    2001-01-01

    The surface of multi-purpose cellulosic office paper has been analysed by inverse gas chromatography (IGC). The parameters determined were the dispersive component of the surface free energy, the enthalpy of adsorption and the entropy of adsorption of polar and apolar probes, the Lewis acidity constant, Ka, and the Lewis basicity constant, Kb. It can be concluded that the dispersive component of the surface free energy, ?sd decreases with temperature, in the range 50–90°C. The temperature coe...

  5. Column Liquid Chromatography.

    Science.gov (United States)

    Majors, Ronald E.; And Others

    1984-01-01

    Reviews literature covering developments of column liquid chromatography during 1982-83. Areas considered include: books and reviews; general theory; columns; instrumentation; detectors; automation and data handling; multidimensional chromatographic and column switching techniques; liquid-solid chromatography; normal bonded-phase, reversed-phase,…

  6. A One-Dimensional (1-D) Three-Region Model for a Bubbling Fluidized-Bed Adsorber

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Andrew; Miller, David C.

    2012-01-01

    A general one-dimensional (1-D), three-region model for a bubbling fluidized-bed adsorber with internal heat exchangers has been developed. The model can predict the hydrodynamics of the bed and provides axial profiles for all temperatures, concentrations, and velocities. The model is computationally fast and flexible and allows for any system of adsorption and desorption reactions to be modeled, making the model applicable to any adsorption process. The model has been implemented in both gPROMS and Aspen Custom Modeler, and the behavior of the model has been verified.

  7. A Study of Adsorptive Characteristics of Australian Coals

    Science.gov (United States)

    Lan, Y. P.; Tsai, L. L.

    2012-04-01

    Ever since the Kyoto Protocol, controlling carbon dioxide emission and reducing its content in atmosphere are very important environmental issues up to today. One of the effective methods for permanent sequestration of anthropogenic CO2 is to inject CO2 into deep, unminable coal seams and recover coal bed methane at the same time. CO2-ECBM technology had been proved to be very promising to meet the needs of both environment and energy. Beside other external environment factors, capacity of CO2 adsorption and CH4 desorption are the most influencing factors in selection of sites for the geological storage of CO2. Therefore, the objective of this study is to understand the relationship between gas adsorption and CO2 sequestration, by various experiments for the characterization of Australian of coals. Generally speaking, coal seam gas comprises mostly of CH4, CO2, C2H6, and N2. However, some of the Australian coals were reported with significant amount of CO2 up to 90%, which might strongly affect their capacity of CO2 capture and storage (CCS). High to medium volatile bituminous coals from Sydney Basin and Bowen Basin, southeast Australia were selected in this study. Experiments include maceral composition and vitrinite reflectance measurements, petrographic analysis, Proximate analysis, Ultimate analysis, specific surface area analysis as well as CO2 and CH4 adsorption experiments were performed. Parameters for difference adsorption functions (Langmuir, BET, D-R and D-A) were then calculated to fit their adsorption isotherms the best fitting curve can then be found. Among these adsorption functions, Langmuir is the most basic and commonly used function theory. The results of all experiments were synthesized to discuss the relations among each other, so as to establish the relationship between gas adsorption and coal characteristics.

  8. Heat transfer design in adsorption refrigeration systems for efficient use of low-grade thermal energy

    International Nuclear Information System (INIS)

    Adsorption refrigeration and heat pump systems have been considered as important means for the efficient use of low-grade thermal energy of 60-150 oC. Sorption systems are merely thermodynamic systems based on heat exchangers, and therefore a good design to optimize heat and mass transfer with reaction or sorption processes is very important, for which the notable technique is the use of expanded graphite to improve both heat and mass transfer in the chemisorption beds. Studies have also shown the need to enhance the heat transfer in adsorption bed by matching with the efficient heat transfer of thermal fluids. Heat pipes and good thermal loop design coupled with adsorption beds could yield higher thermal performance of a sorption system. A novel design with passive evaporation, known as rising film evaporation coupled with a gravity heat pipe was introduced for high cooling output. It has also been shown that the performance of traditional heat and mass recovery in the sorption systems is limited, and novel arrangement of thermal fluid and refrigerant may improve the performance of sorption systems. Based upon the above researches, various sorption systems have been developed, and high performances have been reached. -- Highlights: →Heat transfer design in adsorption refrigeration systems is researched. →Solidified adsorbent is an effective way to improve the heat transfer. →Heat pipe and rising film evaporation could generate high cooling output. With efficient design two adsorption systems are developed. →Double way and double effect cycle is introduced.

  9. Numerical estimation of adsorption energy distributions from adsorption isotherm data with the expectation-maximization method

    Energy Technology Data Exchange (ETDEWEB)

    Stanley, B.J.; Guiochon, G. [Tennessee Univ., Knoxville, TN (United States). Dept. of Chemistry]|[Oak Ridge National Lab., TN (United States)

    1993-08-01

    The expectation-maximization (EM) method of parameter estimation is used to calculate adsorption energy distributions of molecular probes from their adsorption isotherms. EM does not require prior knowledge of the distribution function or the isotherm, requires no smoothing of the isotherm data, and converges with high stability towards the maximum-likelihood estimate. The method is therefore robust and accurate at high iteration numbers. The EM algorithm is tested with simulated energy distributions corresponding to unimodal Gaussian, bimodal Gaussian, Poisson distributions, and the distributions resulting from Misra isotherms. Theoretical isotherms are generated from these distributions using the Langmuir model, and then chromatographic band profiles are computed using the ideal model of chromatography. Noise is then introduced in the theoretical band profiles comparable to those observed experimentally. The isotherm is then calculated using the elution-by-characteristic points method. The energy distribution given by the EM method is compared to the original one. Results are contrasted to those obtained with the House and Jaycock algorithm HILDA, and shown to be superior in terms of robustness, accuracy, and information theory. The effect of undersampling of the high-pressure/low-energy region of the adsorption is reported and discussed for the EM algorithm, as well as the effect of signal-to-noise ratio on the degree of heterogeneity that may be estimated experimentally.

  10. Variability of bed drag on cohesive beds under wave action

    Science.gov (United States)

    Safak, Ilgar

    2016-01-01

    Drag force at the bed acting on water flow is a major control on water circulation and sediment transport. Bed drag has been thoroughly studied in sandy waters, but less so in muddy coastal waters. The variation of bed drag on a muddy shelf is investigated here using field observations of currents, waves, and sediment concentration collected during moderate wind and wave events. To estimate bottom shear stress and the bed drag coefficient, an indirect empirical method of logarithmic fitting to current velocity profiles (log-law), a bottom boundary layer model for combined wave-current flow, and a direct method that uses turbulent fluctuations of velocity are used. The overestimation by the log-law is significantly reduced by taking turbulence suppression due to sediment-induced stratification into account. The best agreement between the model and the direct estimates is obtained by using a hydraulic roughness of 10  m in the model. Direct estimate of bed drag on the muddy bed is found to have a decreasing trend with increasing current speed, and is estimated to be around 0.0025 in conditions where wave-induced flow is relatively weak. Bed drag shows an increase (up to fourfold) with increasing wave energy. These findings can be used to test the bed drag parameterizations in hydrodynamic and sediment transport models and the skills of these models in predicting flows in muddy environments.

  11. Theory of chromatography of partially cyclic polymers: Tadpole-type and manacle-type macromolecules.

    Science.gov (United States)

    Vakhrushev, Andrey V; Gorbunov, Alexei A

    2016-02-12

    A theory of chromatography is developed for partially cyclic polymers of tadpole- and manacle-shaped topological structures. We present exact equations for the distribution coefficient K at different adsorption interactions; simpler approximate formulae are also derived, relevant to the conditions of size-exclusion, adsorption, and critical chromatography. Theoretical chromatograms of heterogeneous partially cyclic polymers are simulated, and conditions for good separation by topology are predicted. According to the theory, an effective SEC-radius of tadpoles and manacles is mostly determined by the molar mass M, and by the linear-cyclic composition. In the interactive chromatography, the effect of molecular topology on the retention becomes significant. At the critical interaction point, partial dependences K(Mlin) and K(Mring) are qualitatively different: while being almost independent of Mlin, K increases with Mring. This behavior could be realized in critical chromatography-for separation of partially cyclic polymers by the number and molar mass of cyclic elements.

  12. Theory of chromatography of partially cyclic polymers: Tadpole-type and manacle-type macromolecules.

    Science.gov (United States)

    Vakhrushev, Andrey V; Gorbunov, Alexei A

    2016-02-12

    A theory of chromatography is developed for partially cyclic polymers of tadpole- and manacle-shaped topological structures. We present exact equations for the distribution coefficient K at different adsorption interactions; simpler approximate formulae are also derived, relevant to the conditions of size-exclusion, adsorption, and critical chromatography. Theoretical chromatograms of heterogeneous partially cyclic polymers are simulated, and conditions for good separation by topology are predicted. According to the theory, an effective SEC-radius of tadpoles and manacles is mostly determined by the molar mass M, and by the linear-cyclic composition. In the interactive chromatography, the effect of molecular topology on the retention becomes significant. At the critical interaction point, partial dependences K(Mlin) and K(Mring) are qualitatively different: while being almost independent of Mlin, K increases with Mring. This behavior could be realized in critical chromatography-for separation of partially cyclic polymers by the number and molar mass of cyclic elements. PMID:26803439

  13. Theoretical and experimental investigation on the transient coupled heat and mass transfer in a radial flow desiccant packed bed

    International Nuclear Information System (INIS)

    Highlights: ► We present theoretical and experimental investigation of desiccant bed. ► Transient coupled heat and mass transfer in a radial flow desiccant packed bed has been reported. ► A real-time model is used. ► The prediction of air exit conditions from the bed is carried out. - Abstract: Theoretical and experimental investigation on the transient coupled heat and mass transfer in a radial flow desiccant packed bed has been reported in the present work. An experimental test rig has been designed and constructed to carry out the required experimental measurements. System parameters and flowing air conditions (bed weight, air velocity, air conditions – dry and wet bulb temperatures- at exit of test rig components) are measured and analyzed. A hollow cylindrical packed bed has been used as a desiccant dehumidifier. This configuration decreases the required power to blow air through the bed. In the theoretical study, prediction of air exit conditions from the bed is carried out based on the model of Barlow for the analysis of adsorption and regeneration processes in the desiccant bed. This model uses simple effectiveness equations for steady-state heat and mass exchangers within a finite difference procedure. Air at different conditions of temperature and humidity enters the regenerated bed and the exit temperature and humidity are plotted with time. Acceptable agreement is found between the theoretical and experimental results. The most effective parameters on the system performance are the initial water content of the bed and its initial temperature. Bed cooling during adsorption improves the system performance.

  14. Continuous cadmium removal from aqueous solutions by seaweed in a packed-bed column under consecutive sorption-desorption cycles

    Energy Technology Data Exchange (ETDEWEB)

    Jafari, Seyed Ali; Jamali, Abbas [Persian Gulf Research Institute, Persian Gulf University, 75169, Bushehr (Iran, Islamic Republic of)

    2016-04-15

    Packed-bed column process efficiency for cadmium adsorption from aqueous solution was investigated under different bed heights (2.6 to 7.5 cm) and feed flow rates (15 to 30 ml min{sup -1}). The column was filled with brown seaweed, Sargassum angustifolium. Three simplified models, including Bed Depth Service Time, Thomas, and Yoon- Nelson were employed for describing the experimental breakthrough curves as well as achieving design parameters. Bed lifetime was also evaluated in several consecutive sorption-desorption cycles. Cadmium concentration of 0.005mg l−1, as a standard limit for potable water, was considered as the breakthrough concentration. The maximum column performance was achieved 81% at 7.5 cm bed length and flow rate of 15 ml min{sup -1}. Indeed, increasing the bed height increased the sorption performance and service time, while increasing the feed flow rate had a negative effect. Maximum sorption capacity value remained almost constant by the bed height changes; however, increase in the feed flow rate slightly decreased it. The modeling results revealed that the Yoon-Nelson model was more accurate than Thomas for describing the experimental breakthrough data, especially at low flow rates. Column service time predictions were surprisingly achieved using the Bed Depth Service Time model even at extrapolations. 20% reduction in column adsorption efficiency was observed at the end of four consecutive sorption-desorption cycles; however, desorption efficiencies were achieved more than 99% in each cycle.

  15. ADSORPTION AND DESORPTION OF DSD ACID MANUFACTURING WASTEWATER ON MACROPOROUS RESIN

    Institute of Scientific and Technical Information of China (English)

    LONG Chao; ZHANG Quanxing; XU Zhaoyi; CHEN Jinlong; LI Aimin; CHENG Zhiqiang

    2001-01-01

    4,4'-diaminostilbene-2, 2'-disulfonic acid (DSD acid) manufacturing wastewater was treated by a macroporous resin in a fixed-bed column. The results showed that this method was suitable for removal of chemical oxygen demands (COD) and color About 91% COD and 99.5% color removal were obtained under the optimum adsorption conditions, i.e. temperature 20 ℃, flow rate 1 bed volume/hour (BV/hr) and pH1-2. The resin was efficiently regenerated with aqueous sodium hydroxide and water. Furthermore, 65.5% of 4, 4 '-dinitrostilbene-2, 2 '-disulfonic acid (DNS) could be recovered from wastewater for possible recycling to the manufacturing process. The adsorption capacity of resin remained constant during the repetition process of adsorption and desorption.

  16. Adsorption process to recover hydrogen from feed gas mixtures having low hydrogen concentration

    Science.gov (United States)

    Golden, Timothy Christopher; Weist, Jr., Edward Landis; Hufton, Jeffrey Raymond; Novosat, Paul Anthony

    2010-04-13

    A process for selectively separating hydrogen from at least one more strongly adsorbable component in a plurality of adsorption beds to produce a hydrogen-rich product gas from a low hydrogen concentration feed with a high recovery rate. Each of the plurality of adsorption beds subjected to a repetitive cycle. The process comprises an adsorption step for producing the hydrogen-rich product from a feed gas mixture comprising 5% to 50% hydrogen, at least two pressure equalization by void space gas withdrawal steps, a provide purge step resulting in a first pressure decrease, a blowdown step resulting in a second pressure decrease, a purge step, at least two pressure equalization by void space gas introduction steps, and a repressurization step. The second pressure decrease is at least 2 times greater than the first pressure decrease.

  17. LSP Composite Test Bed Design

    Science.gov (United States)

    Day, Arthur C.; Griess, Kenneth H.

    2013-01-01

    This document provides standalone information for the Lightning Strike Protection (LSP) Composite Substrate Test Bed Design. A six-sheet drawing set is reproduced for reference, as is some additional descriptive information on suitable sensors and use of the test bed.

  18. Carbon Dioxide/Methane Separation by Adsorption on Sepiolite

    Institute of Scientific and Technical Information of China (English)

    José A.Delgado; María A.Uguina; José L.Sotelo; Beatriz Ruíz; Marcio Rosário

    2007-01-01

    In this work,the use of sepiolite for the removal of carbon dioxide from a carbon dioxide/methane mixture by a pressure swing adsorption (PSA) process has been researched.Adsorption equilibrium and kinetics have been measured in a fixed-bed.and the adsorption equilibrium parameters of carbon dioxide and methane on sepiolite have been obtained.A model based on the LDF approximation has been employed to simulate the fixed-bed kinetics.using the Langmuir equation to describe the adsotption equilibrium isotherm.The functioning of a PSA cycle for separating carbon dioxide/methane mixtures using sepiolite as adsorbent has also been studied.The experimental results were compared with the ones predicted by the model adapted to a PSA system.Methane with purity higher than 97% can be obtained from feeds containing carbon dioxide with concentrations ranging from 34% to 56% with the proposed PSA cycle.These results suggest that sepiolite is an adsorbent with good properties for its employment in a PSA cycle for carbon dioxide removal from landfill gases.

  19. Adsorption of lead and copper ions from aqueous effluents on rice husk ash in a dynamic system

    Directory of Open Access Journals (Sweden)

    M. G. A. Vieira

    2014-06-01

    Full Text Available This study evaluated the kinetic adsorption of Pb and Cu ions using rice husk ash as adsorbent in a fixed bed. The maximum adsorption capacities obtained for lead and copper ions in the fixed bed were 0.0561 and 0.0682 mmol/g (at 20 ºC, respectively. The thermodynamic studies indicated that the lead adsorption process was exothermic and spontaneous, while the copper adsorption process was endothermic and spontaneous. Characterization results indicated the presence of several functional groups, amorphous silica and a fibrous and longitudinal structure of rice husks. Rice husk ash (RHA from northern Brazil can be used as a bioadsorbent for the individual removal of Pb(II and Cu(II ions from metal-containing effluents.

  20. Adsorption/desorption characteristics and separation of anthocyanins from muscadine (Vitis rotundifolia) juice pomace by use of macroporous adsorbent resins.

    Science.gov (United States)

    Sandhu, Amandeep K; Gu, Liwei

    2013-02-20

    In this study, the adsorption/desorption characteristics of anthocyanins on five Amberlite resins (FPX-66, XAD-7HP, XAD-16N, XAD-1180, and XAD-761) were evaluated. FPX-66 and XAD-16N showed the highest adsorption and desorption capacities and ratios for anthocyanins from muscadine pomace extract, while XAD-7HP had the lowest adsorption and desorption capacities and ratios. On the basis of static adsorption and desorption tests, three resins (FPX-66, XAD-16N, and XAD-1180) were selected for adsorption kinetics and isotherms. The adsorption mechanism was better explained by the pseudo-first-order kinetics for FPX-66 and XAD-16N; however, for XAD-1180, pseudo-second-order kinetics was the most suitable model. The experimental data fitted best to Langmuir isotherm model for all three resins. Dynamic testing was done on a column packed with FPX-66 resin and breakthrough volume was reached at 17 bed volumes of muscadine pomace water extract during adsorption. Three bed volumes of aqueous ethanol (70%) resulted in complete desorption. Resin adsorption resulted in a concentrated pomace extract that contained 13% (w/w) anthocyanins with no detectable sugars. PMID:23368425

  1. Chromatographie à contre-courant simulé : développements et perspectives From Batch Elution to Simulated Countercurrent Chromatography

    Directory of Open Access Journals (Sweden)

    Hotier G.

    2006-11-01

    Full Text Available Les applications industrielles et le principe de fonctionnement du procédé de séparation en lit mobile ou en contre-courant simulé sont brièvement rappelés. La réalisation pratique de trois unités pilotes fonctionnant selon ce principe mais employant une technologie innovante est présentée. Cette mise en oeuvre particulière permet de tester par un simple changement de paramètres de contrôle toutes les configurations possibles de l'unité. Cet appareillage particulièrement souple est donc véritablement multitâche, ce qui permet en plus des applications en pétrochimie son emploi dans les domaines de la pharmacie, de la chimie fine et des bioséparations, où existe un grand nombre d'applications potentielles très différentes les unes des autres. Deux exemples de séparations réalisées à l'Institut Français du Pétrole sont succinctement présentés. La conclusion de ces essais est que la modélisation de ces procédés est indispensable pour pouvoir opérer correctement ce type d'unité. Une comparaison entre la chromatographie d'élution et cette technique de séparation ainsi que quelques propositions d'amélioration du procédé permettront au lecteur de se faire une idée sur l'extension potentielle de ce type de séparation. Distillation is and will for quite a long time remain the main separation technique in the refining, petrochemical and chemical industries. Some separations however cannot be performed by distillation when the products to be separated are subject to thermal degradation or when their boiling points are too close. Under these circumstances adsorption or chromatographic processes are interesting alternatives. In the 1960's and in the early 1970's the technology of the simulated moving bed, the UOP rotary valve and the application of these devices to separation processes were introduced by UOP. Nowadays simulated moving bedor countercurrentseparation processes may be found in the petrochemical industry

  2. A mass transfer in heterogeneous systems by the adsorption method (

    Directory of Open Access Journals (Sweden)

    N. Bošković-Vragolović

    2009-01-01

    Full Text Available A mass transfer coefficient between: a liquid and single sphere and a liquid and column wall in packed and fluidized beds of a spherical inert particle have been studied experimentally using the adsorption method. The experiments were conducted in a column 40 mm in diameter for packed and fluidized beds, and in a two-dimensional column 140 mm×10 mm for the flow past single sphere. In all runs, the mass transfer rates were determined in the presence of spherical glass particles, 3 mm in diameter, for packed and fluidized beds. The mass transfer data were obtained by studying transfer for flow past single sphere, 20 mm in diameter. This paper discusses the possibilities of application of the adsorption method for fluid flow visualization. Local and average mass transfer coefficients were determined from the color intensity of the surface of the foils of silica gel. Correlations, Sh = f(Re and jD = f(Re, were derived using the mass transfer coefficient data.

  3. 用FA和ECM方法测定吸附等温线的比较%Comparison of Frontal Analysis and Elution-Curve Method for Determining Adsorption Isotherms

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Adsorption isotherm is the most fundamental information related to chromatography. To calculate the parameters of Langmuir adsorption isotherm of thymidine, frontal analysis (FA) and elution-curve method (ECM) were adopted in reversed-phase high performance liguid chromatography (RP-HPLC). In FA, the concentration of stationary phase was measured from the elution curves and the isotherm was determined by regression analysis, while the parameters by ECM were obtained by parameter optimization. The adsorption isotherms of thymidine from the two methods were very similar. The superiority of ECM over FA was that the consumption of sample was less and only one or two injections of sample were required.

  4. A transverse isotropic model for microporous solids: Application to coal matrix adsorption and swelling

    Science.gov (United States)

    Espinoza, D. N.; Vandamme, M.; Dangla, P.; Pereira, J.-M.; Vidal-Gilbert, S.

    2013-12-01

    Understanding the adsorption-induced swelling in coal is critical for predictable and enhanced coal bed methane production. The coal matrix is a natural anisotropic disordered microporous solid. We develop an elastic transverse isotropic poromechanical model for microporous solids which couples adsorption and strain through adsorption stress functions and expresses the adsorption isotherm as a multivariate function depending on fluid pressure and solid strains. Experimental data from the literature help invert the anisotropic adsorptive-mechanical properties of Brzeszcze coal samples exposed to CO2. The main findings include the following: (1) adsorption-induced swelling can be modeled by including fluid-specific and pressure-dependent adsorption stress functions into equilibrium equations, (2) modeling results suggest that swelling anisotropy is mostly caused by anisotropy of the solid mechanical properties, and (3) the total amount of adsorbed gas measured by immersing coal in the adsorbate overestimates adsorption amount compared to in situ conditions up to ˜20%. The developed fully coupled model can be upscaled to determine the coal seam permeability through permeability-stress relationships.

  5. Comparison of Frontal Analysis and Elution-Curve Method for Determining Adsorption Isotherms

    Institute of Scientific and Technical Information of China (English)

    Ju-Weon; LEE; Kyung; Ho; ROW

    2002-01-01

    Adsorption isotherm is the most fundamental information related to chromatography.To calculate the parameters of Langmuir adsorption isotherm of thymidine,fronal analysis(FA)and lution-curve method(ECM)were adopted in reversed-phase high performance liguid chromatography(RP-HPLC).In FA,tha concentration of stationary phase was measured from the elution curves and the isotherm was determined by regression analysis,while the parameters by ECM were obtained by parameter optimization.The adsorption isotherms of thymidine from the two methods were very similar.The superiority of ECM over FA was that the consumption of sample was less and only one or two in jections of sample were required.

  6. Comparison of Fixed and Fluidized Beds Adsorber with Economic, Engineering, and Environmental approach

    Directory of Open Access Journals (Sweden)

    SEDIGHEH ATRKAR-ROSHAN

    2015-10-01

    Full Text Available Release  Volatile  organic  compounds  (VOCs  as  environmental  and  occupational  pollutant  cause  macro perspective affect such as climate change, humans and economic consequences. Although fixed bed absorber is widely used as a controlling method because of its economically and availability, but these absorbers are facing some issue like high pressure drop, non-uniform distribution of fluid, channeling and blocking. Fixed and fluidized beds adsorbent was compared from three economic, environmental and engineering perspectives using Multi Criteria Decision Making analysis (MCDA technique. An annular fluidized bed adsorber was designed and charged with 50-100 µm (100-140 ASTM mesh activated carbon (AC particles. Effects of factors like flow rate, particle size, inlet concentration and adsorption capacity of VOCs was investigated under steady state. In the flow rate less than 0.25(Lit.min-1, inlet gas slowly passes through the void spaces of the bed’s particles. By increasing the inlet flow from 0.3(Lit/min-1, bubbles start to form in the bed and the bed pressure drop decrease. The pressure drop of 6 (g of AC in minimum fluidization velocity was 20(KN.m-2. However, the pressure drop of 10 and 20(g of AC were 150 and 420(KN.m-2 respectively. “maximin” technique used for comparison of two beds indicated that minimum score of pack bed absorber are 0.37 while the minimum score of fluidized bed adsorber are 0.5. It indicated when the adsorbent particles are smaller, fluidized bed adsorber are more suitable to use. In addition, using MCDA technique indicated that annular fluidized bed adsorber could considered as an alternative of fixed beds adsorber.

  7. Investigation of Adsorbed Gases Content in Coal Beds in Bosnia and Herzegovina

    Directory of Open Access Journals (Sweden)

    Sadadinovic, J.

    2008-09-01

    Full Text Available Investigation of the gas fraction in coal beds in Bosnia & Herzegovina has been performed systematically since 1988. Gas in coal beds can be present in free or adsorbed form, and dissolved in water. Methods of investigation are based on the direct approach, according to which the gas fraction is determined in the undisturbed coal bed.The quantity of the adsorbed and free gas in the coal bed is directly proportional to the gas pressure. Dependence is hyperbolic. The quantity of the free gas in mining conditions is being determined by measurement of the desorption index (Δp2. The desorption index for the Srednjobosanski coal basin ranges to 1571 Pa, and the free gas pressure in this coal basin amounts up to 3.75 MPa. The desorption index for coal beds in “Kreka” and “Banoviće” coal basins has negative values, which means that the free gas fraction within the coal beds is negligible, while separation of adsorbed gases is diffuse. The free gas pressure in the mentioned coal basins is below 0.1 MPa. Adsorbed gases within the coal are connected by physical adsorption according to Langmuir’s isothermal adsorption curve. Langmuir’s quantities, for coal bed conditions, ranges as follows: am from 0.826 to 9.52 m3 t–1 pcs, and b from 6.65 10–3 to 0.247 MPa–1. Adsorbed gas within Miocene coal beds contains methane in amounts of 1.49 m3 t–1 čus CH4 andcarbon(IVoxide in amounts of 0.15 m3 t–1 čus CO2. Adsorbed gas within Pliocene coal beds, without methane, dominant is content of carbon(IVoxide.The investigation of the gas content in coal beds of BiH conducted in this article reveal that the coal beds primarily contain methane, while others hydrocarbons such as ethane, ethene, propane, propene and butane are present sporadically in fraction below φ/10–6. Based on the investigation results conducted in this article, simple mathematical forms were obtained for quick calculation of the free gas quantity by measurement of the

  8. Techno-Economic Study of Adsorption Processes for Pre-Combustion Carbon Capture at a Biomass CHP Plant

    OpenAIRE

    Oreggioni, Gabriel David; Friedrich, Daniel; Brandani, Stefano; Ahn, Hyungwoong

    2014-01-01

    An exemplary 10 MWth biomass CHP plant with a FICFB (Fast Internally Circulating Fluidised Bed) gasifier and Jenbacher type 6 gas engine was simulated to estimate the power and thermal outputs. The biomass-fuelled CHP plant was modified for carbon capture using either adsorption or amine process. It was found that a two-stage, two-bed PVSA (Pressure Vacuum Swing Adsorption) unit applied to syngas stream for pre-combustion capture spent less specific energy per captured CO2 than a conventional...

  9. Wall-to-bed heat transfer in circulating fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Fox, W.B.; Grewal, N.S.; Moen, D.A. [Univ. of North Dakota, Grand Forks, ND (United States). Mechanical Engineering Dept.

    1999-05-01

    Circulating fluidized beds (CFBs) have become increasingly important in recent years for coal combustion and gas-solid reactions. Here, heat transfer from the wall of a circulating fluidized bed to the fast bed suspension has been investigated for several materials. The range of investigation includes dense and dilute phase fast fluidization and pneumatic transport. The overall heat transfer coefficient was found to be a function mainly of cross-sectional average suspension density. Effects of superficial velocity and solids mass flux were obscured by their interrelationship to the suspension density. Two models from the literature are evaluated using present and published data.

  10. Performance of an activated carbon made from waste palm shell in simultaneous adsorption of SO_x and NO_x of flue gas at low temperature

    Institute of Scientific and Technical Information of China (English)

    S.; SUMATHI; S.; BHATIA; K.T.; LEE; A.; R.; MOHAMED

    2009-01-01

    This study examined the individual and simultaneous adsorption of SOx (SO2) and NOx (NO-NO2) on activated carbon prepared from waste palm shell. The adsorption process was examined in a fixed bed reactor at low temperatures (100―300℃). For individual adsorption without any catalytic activation, SOx showed good adsorption whereas NOx was very much poor. In the simultaneous adsorption of SOx and NOx, SOx showed greater adsorption affinity than NOx. For palm shell activated carbon (PSAC) impregnated with metal catalyst (Ni and Ce) the concentration adsorbed profile showed that the amount of SOx adsorbed decreased regularly, while the amount of the adsorbed NOx increased irregularly. The properties of the pure and impregnated PSAC were analyzed by BET, SEM and EDX. These investiga-tions indicated that PSAC impregnated with metal catalyst is the determining factor in the adsorption of SOx and NOx simultaneously.

  11. Performance of an activated carbon made from waste palm shell in simultaneous adsorption of SOx and NOx of flue gas at low temperature

    Institute of Scientific and Technical Information of China (English)

    S.SUMATHI; S.BHATIA; K.T.LEE; A.R.MOHAMED

    2009-01-01

    This study examined the individual and simultaneous adsorption of SOx (SO2) and NOx (NO-NO2) on activated carbon prepared from waste palm shell. The adsorption process was examined in a fixed bed reactor at low temperatures (100-300℃). For individual adsorption without any catalytic activation, SOx showed good adsorption whereas NOx was very much poor. In the simultaneous adsorption of SOx and NOx, SOx showed greater adsorption affinity than NOx. For palm shell activated carbon (PSAC) im-pregnated with metal catalyst (Ni and Ce) the concentration adsorbed profile showed that the amount of SOx adsorbed decreased regularly, while the amount of the adsorbed NOx increased irregularly. The properties of the pure and impregnated PSAC were analyzed by BET, SEM and EDX. These investiga-tions indicated that PSAC impregnated with metal catalyst is the determining factor in the adsorption of SOxand NOx simultaneously.

  12. Copper adsorption in tropical oxisols

    Directory of Open Access Journals (Sweden)

    Silveira Maria Lucia Azevedo

    2003-01-01

    Full Text Available Cu adsorption, at concentrations between 0 to 800 mg L-1, was evaluated in surface and subsurface samples of three Brazilian soils: a heavy clayey-textured Rhodic Hapludalf (RH, a heavy clayey-textured Anionic ''Rhodic'' Acrudox (RA and a medium-textured Anionic ''Xanthic'' Acrudox (XA. After adsorption, two consecutive extractions were performed to the samples which received 100 mg L-1 copper. Surface samples adsorbed higher amounts of Cu than the subsurface, and exhibited lower Cu removed after the extractions, reinforcing the influence of the organic matter in the reactions. Cu adsorption was significant in the subsurface horizons of the Oxisols, despite the positive balance of charge, demonstrating the existence of mechanisms for specific adsorption, mainly related to the predominance of iron and aluminum oxides in the mineral fractions. In these samples, Cu was easily removed from the adsorption sites. RH demonstrated a higher capacity for the Cu adsorption in both horizons.

  13. Pulling a patient up in bed

    Science.gov (United States)

    Moving a patient in bed ... You must move or pull someone up in bed the right way to avoid injuring the patient's ... people to safely move a patient up in bed. Friction from rubbing can scrape or tear the ...

  14. Chitinolytic Bacteria-Assisted Conversion of Squid Pen and Its Effect on Dyes and Pigments Adsorption

    Directory of Open Access Journals (Sweden)

    Tzu-Wen Liang

    2015-07-01

    Full Text Available The aim of this work was to produce chitosanase by fermenting from squid pen, and recover the fermented squid pen for dye removal by adsorption. One chitosanase induced from squid pen powder (SPP-containing medium by Bacillus cereus TKU034 was purified in high purification fold (441 and high yield of activity recovery (51% by ammonium sulfate precipitation and combined column chromatography. The SDS-PAGE results showed its molecular mass to be around 43 kDa. The TKU034 chitosanase used for the chitooligomers preparation was studied. The enzyme products revealed that the chitosanase could degrade chitosan with various degrees of polymerization, ranging from 3 to 9, as well as the chitosanase in an endolytic manner. Besides, the fermented SPP was recovered and displayed a better adsorption rate (up to 99.5% for the disperse dyes (red, yellow, blue, and black than the water-soluble food colorants, Allura Red AC (R40 and Tartrazine (Y4. The adsorbed R40 on the unfermented SPP and the fermented SPP was eluted by distilled water and 1 M NaOH to confirm the dye adsorption mechanism. The fermented SPP had a slightly higher adsorption capacity than the unfermented, and elution of the dye from the fermented SPP was easier than from the unfermented. The main dye adsorption mechanism of fermented SPP was physical adsorption, while the adsorption mechanism of unfermented SPP was chemical adsorption.

  15. Investigation of hydrodynamic parameters in a novel expanded bed configuration: local axial dispersion characterization and an empirical correlation study

    Directory of Open Access Journals (Sweden)

    E. S. Taheri

    2012-12-01

    Full Text Available Study of liquid behavior in an expanded bed adsorption (EBA system is important for understanding, modeling and predicting nanobioproduct/biomolecule adsorption performance in such processes. In this work, in order to analyze the local axial dispersion parameters, simple custom NBG (Nano Biotechnology Group expanded bed columns with 10 and 26 mm inner diameter were modified by insertion of sampling holes. Based on this configuration, the particles and liquid can be withdrawn directly from various axial positions of the columns. Streamline DEAE particles were used as solid phase in this work. The effects of factors such as liquid velocity, viscosity, settled bed height and column diameter on the hydrodynamic parameters were investigated. Local bed voidages in different axial bed positions were measured by a direct procedure within the column with 26 mm diameter. Increasing trend of voidage with velocity at a certain position of the bed and with bed height at a certain degree of expansion was observed. Residence time distribution (RTD analysis at various bed points showed approximately uniform hydrodynamic behavior in the column with 10 mm diameter while a decreasing trend of mixing/dispersion along the bed height at a certain degree of expansion was seen in the column with 26 mm diameter. Also lower mixing/dispersion occured in the smaller diameter column. Finally, a combination of two empirical correlations proposed by Richardson-Zaki and Tong-Sun was successfully employed for identification of the bed voidage at various bed heights (RSSE=99.9%. Among the empirical correlations presented in the literatures for variation of the axial dispersion coefficient, the Yun correlation gave good agreement with our experimental data (RSSE=87% in this column.

  16. Finite Element Modeling of Adsorption Processes for Gas Separation and Purification

    International Nuclear Information System (INIS)

    Pacific Northwest National Laboratory (PNNL) has expertise in the design and fabrication of automated radioxenon collection systems for nuclear explosion monitoring. In developing new systems there is an ever present need to reduce size, power consumption and complexity. Most of these systems have used adsorption based techniques for gas collection and/or concentration and purification. These processes include pressure swing adsorption, vacuum swing adsorption, temperature swing adsorption, gas chromatography and hybrid processes that combine elements of these techniques. To better understand these processes, and help with the development of improved hardware, a finite element software package (COMSOL Multiphysics) has been used to develop complex models of these adsorption based operations. The partial differential equations used include a mass balance for each gas species and adsorbed species along with a convection conduction energy balance equation. These equations in conjunction with multicomponent temperature dependent isotherm models are capable of simulating separation processes ranging from complex multibed PSA processes, and multicomponent temperature programmed gas chromatography, to simple two component temperature swing adsorption. These numerical simulations have been a valuable tool for assessing the capability of proposed processes and optimizing hardware and process parameters.

  17. Adsorption of polyhydroxyl based surfactants

    OpenAIRE

    Matsson, Maria

    2005-01-01

    Adsorption on solid surfaces from solution is a fundamental property of a surfactant. It might even be the most important aspect of surfactant behavior, since it influences many applications, such as cleaning, detergency, dispersion, separation, flotation, and lubrication. Consequently, fundamental investigations of surfactant adsorption are relevant to many areas. The main aim of this thesis has been to elucidate the adsorption properties, primarily on the solid/water interface, of a particu...

  18. Determination of 11 anabolic hormones in fish tissue by multifunction impurity adsorption solid-phase extraction-ultrafast liquid chromatography-tandem mass spectrometry%多重机制杂质吸附萃取净化-快速液相色谱-串联质谱法测定鱼组织中11种同化激素

    Institute of Scientific and Technical Information of China (English)

    姚珊珊; 赵永纲; 李小平; 陈晓红; 金米聪

    2012-01-01

    建立了准确、灵敏的鱼组织中11种同化激素(勃地酮、雄烯二酮、诺龙、美雄酮、甲睾酮、睾酮、醋酸睾酮、群勃龙、丙酸睾酮、康力龙、氟甲睾酮)的多重机制杂质吸附萃取净化-快速液相色谱-串联质谱的分析方法.鱼组织均质样品经甲醇提取后,在上清液中加入一定量的C18固体吸附剂、中性氧化铝吸附剂和氨基功能化纳米吸附剂实现快速净化.采用Shim-Pack XR-ODSⅡ色谱柱(100 mm×2.0 mm,2.2μm)分离,以乙腈(含0.1%甲酸)和水(含0.1%甲酸)为流动相进行梯度洗脱,电喷雾正离子多反应监测( MRM)模式下检测,外标法定量.结果表明,11种目标化合物在线性范围内具有良好的线性关系,相关系数大于0.999,其在鱼组织中的检出限(S/N>3)为0.03 ~0.4 μg/kg,定量限(S/N> 10)为0.1~1.5μg/kg,平均回收率为80.9%~98.1%,相对标准偏差(RSD)为5.2%~11.5%.该方法简便、快速、准确,可用于鱼组织中同化激素的定性、定量监测.%A method was developed for the determination of 11 anabolic hormones (bolde-none, androstenedione, nandrolbne, methandrostenolone, methyltestosterone, testosterone, testosterone acetate, trenbolone, testosterone propionate, stanozolol, fluoxymesterone) in fish by multi-function impurity adsorption solid-phase extraction-ultrafast liquid chromatography-tandem mass spectrometry. After the sample was extracted by methanol, the extract was cleaned-up quickly by C18 adsorbent, neutral alumina adsorbent and amino-functionalized nano-adsorbent. The separation was performed on a Shim-Pack XR-ODS II column (100 mm x 2.0 mm, 2. 2 |xm) using the mobile phases of 0. 1% (v/v) formic acid in acetonitrile and 0. 1% (v/v) formic acid solution in a gradient elution mode. The identification and quantification were achieved by using electrospray ionization in positive ion mode (ESI *) in multiple reaction monitoring (MRM) mode. The matrix-matched external standard

  19. Liquid Chromatography on chip

    OpenAIRE

    Faure, Karine

    2010-01-01

    Abstract Liquid chromatography is one of the most powerful separation techniques as illustrated by its leading role in analytical sciences through both academic and industrial communities. Its implementation in microsystems appears to be crucial in the development of ?TAS. If electrophoretic techniques have been widely used in miniaturized devices, liquid chromatography has faced multiple challenges in the downsizing process. During the past five years significant breakthroughs...

  20. Gas chromatography in space

    Science.gov (United States)

    Akapo, S. O.; Dimandja, J. M.; Kojiro, D. R.; Valentin, J. R.; Carle, G. C.

    1999-01-01

    Gas chromatography has proven to be a very useful analytical technique for in situ analysis of extraterrestrial environments as demonstrated by its successful operation on spacecraft missions to Mars and Venus. The technique is also one of the six scientific instruments aboard the Huygens probe to explore Titan's atmosphere and surface. A review of gas chromatography in previous space missions and some recent developments in the current environment of fiscal constraints and payload size limitations are presented.

  1. How to dose powdered activated carbon in deep bed filtration for efficient micropollutant removal.

    Science.gov (United States)

    Altmann, Johannes; Ruhl, Aki S; Sauter, Daniel; Pohl, Julia; Jekel, Martin

    2015-07-01

    Direct addition of powdered activated carbon (PAC) to the inlet of a deep bed filter represents an energy- and space-saving option to remove organic micropollutants (OMPs) during advanced wastewater treatment or drinking water purification. In this lab-scale study, continuous dosing, preconditioning a filter with PAC and combinations thereof were investigated as possible dosing modes with respect to OMP adsorption efficiency. Continuous dosing resulted in decreasing effluent concentrations with increasing filter runtime due to adsorption onto accumulating PAC in the filter bed. Approximately constant removal levels were achieved at longer filter runtimes, which were mainly determined by the dose of fresh PAC, rather than the total PAC amount embedded. The highest effluent concentrations were observed during the initial filtration stage. Meanwhile, preconditioning led to complete OMP adsorption at the beginning of filtration and subsequent gradual OMP breakthrough. PAC distribution in the pumice filter was determined by the loss on ignition of PAC and pumice and was shown to be relevant for adsorption efficiency. Preconditioning with turbulent upflow led to a homogenous PAC distribution and improved OMP adsorption significantly. Combining partial preconditioning and continuous dosing led to low initial effluent concentrations, but ultimately achieved concentrations similar to filter runs without preconditioning. Furthermore, a dosing stop prior to the end of filtration was suitable to increase PAC efficiency without affecting overall OMP removals. PMID:25898248

  2. Adsorption and collective paramagnetism

    CERN Document Server

    Selwood, Pierce W

    1962-01-01

    Adsorption and Collective Paramagnetism describes a novel method for studying chemisorption. The method is based on the change in the number of unpaired electrons in the adsorbent as chemisorption occurs. The method is applicable to almost all adsorbates, but it is restricted to ferromagnetic adsorbents such as nickel, which may be obtained in the form of very small particles, that is to say, to ferromagnetic adsorbents with a high specific surface. While almost all the data used illustratively have been published elsewhere this is the first complete review of the subject. The book is addresse

  3. Dynamic adsorption of chromium ions onto natural and crosslinked chitosan membranes for wastewater treatment

    Directory of Open Access Journals (Sweden)

    Emerson Meneghetti

    2010-03-01

    Full Text Available Water pollution with heavy metals is a matter of major concern for public health and also for natural resource management. The present study investigated the effect of chemical modifications on biopolymeric adsorbents (based on chitosan membranes for chromium removal using fixed-bed dynamic adsorption technique. Parameters such as flow rate, initial concentration and crosslinking agents were evaluated, from a practical point-of-view, in order to optimize the adsorption capacity of natural, glutaraldehyde and epichlorohydrin crosslinked chitosan membranes. The adsorption capacity of natural and epiclorohydrin-crosslinked chitosan membranes were very close to each other; however, glutaraldehyde-crosslinked chitosan membranes presented nearly twice the adsorption capacity compared to the other membranes, being the most promising adsorbent in such mass-transfer systems.

  4. THE SEPARATION,PURIFICATION AND DECOLORIZATION OF NEW ANTIBIOTICS—MILUPEINAN USING ADSORPTION RESIN

    Institute of Scientific and Technical Information of China (English)

    ZHANGYifeng; YINShougen; 等

    2002-01-01

    Adsorption resin AAS was used for the separation and purification of milupeinan(M-13) from its mother liquor.The good adsorption property of AAS adsorption resin was found for milupeinan(M-13) compared with the Diaion CHP 20p.When acetone and water (2:1 in volume) were used as desorption reagents,it was found that 3 times of bed volume of the desorption reagents would make the AAS resin which was saturately adsorpted M-13 desorption completely.Also a macroporous anion exchange resin(Poly-4-vinylpyridine type) D-280 was used for the decolourization from M-13 solution.Good results was given when the sv=1-2.

  5. Pressure swing adsorption modeling of acetone and toluene on activated carbon

    Institute of Scientific and Technical Information of China (English)

    唐琳; 李立清; 邢俊东; 刘峥; 姚小龙

    2013-01-01

    A five steps pressure swing adsorption process was designed for acetone and toluene mixtures separation and recovery. Dynamic distributions of gas phase content and temperature were investigated. Based on the theory of Soret and Dufour, a non-isothermal mathematical model was developed to simulate the PSA process. Effects of heat and mass transfer coefficients were studied. The coupled Soret and Dufour effects were also evaluated. It is found that the heat transfer coefficient has little effect on mass transfer in adsorption stage. However, it has some impacts in desorption stage. The maximum value of C/C0 increases by about 25% as heat transfer coefficient decreases. The temperature variation is less than 0.05 K with the change of mass transfer coefficient, so that the effect of mass transfer coefficient on heat transfer can be ignored. It is also concluded that the Soret and Dufour coupled effects are not obvious in pressure swing adsorption compared with fixed-bed adsorption.

  6. [Degradation and adsorption behavior of napropamide in soils].

    Science.gov (United States)

    Guo, Hua; Zhu, Hong-mei; Yang, Hong

    2008-06-01

    Chromatography (HPLC and GC-MS) and spectroscopy (UV and FT-IR) methods were conducted to study the degradation and adsorption behavior of napropamide in soils. Influence factors of degradation, degradation products and adsorption mechanism were analyzed. The results showed that degradation rate of napropamide increased with enhancing temperature (15-35 degrees C) and organic matter content in soil was the most important factor which influenced the degradation half-life of napropamide in soil, and their relative coefficient (r) reached 0.9794. The degradation half-life of napropamide in sterilized soil was almost 3-fold of that in non-sterilized soil, and soil microorganisms were contributed to the degradation of napropamide. The probable degradation products were N-methyl-2-(1-naphthoxy)-propionamide and N-ethyl-2-(1-naphthoxy)-propionamide. The possible degradation pathways were dealkylation. Adsorption isoterms of napropamide on three soils such as Yellow-brown soil, Latersol and Black Soil could be described by Freundlich equation with the corresponding adsorption coefficient (Kf) of 1.29, 3.43 and 13.36, and the adsorption free energy (delta G) of napropamide on the three soils was less than 40 kJ x mol(-1) which largely resulted from the physical adsorption involving in hydrogen-bonding, hydrophobic bonding, coordination and van der waal force. Comparison to the FT-IR spectra of the three soils, the results certificated that the sorption capacity of three soils was Black Soil > Latersol > Yellow-brown Soil. PMID:18763531

  7. Torsion testing of bed joints

    DEFF Research Database (Denmark)

    Hansen, Klavs Feilberg; Pedersen, Carsten Mørk

    2008-01-01

    This paper describes a simple test method for determining the torsion strength of a single bed joint between two bricks and presents results from testing using this test method. The setup for the torsion test is well defined, require minimal preparation of the test specimen and the test can...... be carried out directly in a normal testing machine. The torsion strength is believed to be the most important parameter in out-of-plane resistance of masonry walls subjected to bending about an axis perpendicular to the bed joints. The paper also contains a few test results from bending of small walls about...... an axis perpendicular to the bed joints, which indicate the close connection between these results and results from torsion tests. These characteristics make the torsion strength well suited to act as substitute parameter for the bending strength of masonry about an axis perpendicular to the bed joints....

  8. Sea bed mapping and inspection

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The conference has 24 presentations on the topics: Sea bed mapping, inspection, positioning, hydrography, marine archaeology, remote operation vehicles and computerized simulation technologies, oil field activities and plans, technological experiences and problems. (tk)

  9. Bed Bugs: The Australian Response

    Directory of Open Access Journals (Sweden)

    Richard C. Russell

    2011-04-01

    Full Text Available Australia has experienced a sudden and unexpected resurgence in bed bug infestations from both Cimex lectularius L. and Cimex hemipterus F. A survey in 2006 revealed that infestations had increased across the nation by an average of 4,500% since the start of the decade. In response, a multi-disciplinary approach to combat the rise of this public health pest was implemented and involved the coordinated efforts of several organizations. The key components of the strategy included the introduction of a pest management standard ‘A Code of Practice for the Control of Bed Bug Infestations in Australia’ that defines and promotes ‘best practice’ in bed bug eradication, the development of a policy and procedural guide for accommodation providers, education of stakeholders in best management practices, and research. These strategies continue to evolve with developments that lead to improvements in ‘best practice’ while bed bugs remain problematic in Australia.

  10. Better backs by better beds?

    DEFF Research Database (Denmark)

    Bergholdt, Kim; Fabricius, Rasmus N; Bendix, Tom

    2008-01-01

    using the probably most relevant "worst case" data. There were no relevant difference between the effects of the water bed and the foam bed. CONCLUSION: The Waterbed and foam mattress' did influence back symptoms, function and sleep more positively as apposed to the hard mattress, but the differences...... mattresses have a positive effect on LBP, and especially a hard mattress is commonly believed to have a positive effect. METHODS: One hundred sixty CLBP patients were randomized to 1 of 3 groups, having a mattress/bed mounted in their sleeping room for 1 month. The beds were: (1) waterbed (Akva), (2) body......-conforming foam mattress (Tempur), and (3) a hard mattress (Innovation Futon). At baseline and after 4 weeks, a blinded observer interviewed the patients on LBP levels (0-10), daily function (activities of daily living, 0-30), and on the amount of sleeping hours/night. RESULTS: Because of dropout of 19 patients...

  11. Properties of Spent Active Coke Particles Analysed via Comminution in Spouted Bed

    Science.gov (United States)

    Buczek, Bronislaw

    2013-01-01

    Samples of active coke, fresh and spent after cleaning flue gases from communal waste incinerators, were investigated. The outer layers of both coke particles were separately removed by comminution in a spouted bed. The samples of both active cokes were analysed by means of densities, mercury porosimetry, and adsorption technique. Remaining cores were examined to determine the degree of consumption of coke by the sorption of hazardous emissions (SO2, HCl, and heavy metals) through its bed. Differences in contamination levels within the porous structure of the particles were estimated. The study demonstrated the effectiveness of commercial active coke in the cleaning of flue gases. PMID:24459454

  12. Properties of spent active coke particles analysed via comminution in spouted bed.

    Science.gov (United States)

    Buczek, Bronislaw

    2013-01-01

    Samples of active coke, fresh and spent after cleaning flue gases from communal waste incinerators, were investigated. The outer layers of both coke particles were separately removed by comminution in a spouted bed. The samples of both active cokes were analysed by means of densities, mercury porosimetry, and adsorption technique. Remaining cores were examined to determine the degree of consumption of coke by the sorption of hazardous emissions (SO2, HCl, and heavy metals) through its bed. Differences in contamination levels within the porous structure of the particles were estimated. The study demonstrated the effectiveness of commercial active coke in the cleaning of flue gases. PMID:24459454

  13. The influence of protein aggregation on adsorption kinetics

    Science.gov (United States)

    Rovner, Joel; Roberts, Christopher; Furst, Eric; Hudson, Steven

    2015-03-01

    When proteins adsorb to an air-water interface they lower the surface tension and may form an age-dependent viscoelastic film. Protein adsorption to surfaces is relevant to both commercial uses and biological function. The rate at which the surface tension decreases depends strongly on temperature, solution pH, and protein structure. These kinetics also depend on the degree to which the protein is aggregated in solution. Here we explore these differences using Chymotrypsinogen as a model protein whose degree of aggregation is adjusted through controlled heat treatment and measured by chromatography. To study these effects we have used a micropipette tensiometer to produce a spherical-cap bubble whose interfacial pressure was controlled - either steady or oscillating. Short heat treatment produced small soluble aggregates, and these adsorbed faster than the original protein monomer. Longer heat treatment produced somewhat larger soluble aggregates which adsorbed more slowly. These results point to complex interactions during protein adsorption.

  14. Adsorption interaction of astatine species with quartz and gold surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Serov, A. [Paul Scherrer Institute, Villigen (Switzerland). Lab. for Radiochemistry and Environmental Chemistry; Bern Univ. (Switzerland). Dept. for Chemistry and Biochemistry; Aksenov, N.; Bozhikov, G. [Joint Institute for Nuclear Research, Dubna (RU). Flerov Lab. of Nuclear Reactions] (and others)

    2011-07-01

    The adsorption interaction of various astatine species with quartz and gold surfaces was investigated by gas chromatography methods. Due to variations of the redox potential of the carrier gas elemental astatine, astatine oxide and hypo-astatic acid have been produced. The identification of the astatine compounds is based on the analogy assumption to the gas phase chemistry of the closest homologues in group 17 of the periodic table, iodine and bromine. The deposition temperatures as well as enthalpies of adsorption have been determined for the astatine species. The enhancement of the metallic character within group 17 towards higher Z is clearly confirmed. Macroscopic properties (sublimation enthalpy) of previously unstudied AtO{sub 2} and HAtO were estimated. The determined data for elemental astatine were compared to available literature data. Based on the obtained experimental results possible designs of experiments for studying of chemical properties of the recently discovered element 117 can be suggested. (orig.)

  15. Planar gas chromatography column on aluminum plate with multi-walled carbon nanotubes as stationary phase

    Science.gov (United States)

    Platonov, I. A.; Platonov, V. I.; Pavelyev, V. S.

    2016-04-01

    The high selectivity of the adsorption layer for low-boiling alkanes is shown, the separation factor (α) couple iso-butane / butane is 1.9 at a column temperature of 50 °C.The paper presents sorption and selective properties of planar gas chromatography column on aluminum plate with multi-walled carbon nanotubes as the stationary phase.

  16. Silver impregnated carbon for adsorption and desorption of elemental mercury vapors

    Institute of Scientific and Technical Information of China (English)

    Despina Karatza; Marina Prisciandaro; Amedeo Lancia; Dino Musmarra

    2011-01-01

    The Hg0 vapor adsorption experimental results on a novel sorbent obtained by impregnating a commercially available activated carbon (Darco G60 from BDH) with silver nitrate were reported.The study was performed by using a fundamental approach,in an apparatus at laboratory scale in which a synthetic flue gas,formed by Hg0 vapors in a nitrogen gas stream,at a given temperature and mercury concentration,was flowed through a fixed bed of adsorbent material.Breakthrough curves and adsorption isotherms were obtained for bed temperatures of 90,120 and 150°C and for Hg0 concentrations in the gas varying in the range of 0.8-5.0 mg/m3.The experimental gas-solid equilibrium data were used to evaluate the Langmuir parameters and the heat of adsorption.The experimental results showed that silver impregnated carbon was very effective to capture elemental mercury and the amount of mercury adsorbed by the carbon decreased as the bed temperature increased.In addition,to evaluate the possibility of adsorbent recovery,desorption was also studied.Desorption runs showed that both the adsorbing material and the mercury could be easily recovered,since at the end of desorption the residue on solid was almost negligible.The material balance on mercury and the constitutive equations of the adsorption phenomenon were integrated,leading to the evaluation of only one kinetic parameter which fits well both the experimentally determined breakthrough and desorption curves.

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

    International Nuclear Information System (INIS)

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

  18. Liquid-Phase Adsorption Fundamentals.

    Science.gov (United States)

    Cooney, David O.

    1987-01-01

    Describes an experiment developed and used in the unit operations laboratory course at the University of Wyoming. Involves the liquid-phase adsorption of an organic compound from aqueous solution on activated carbon, and is relevant to adsorption processes in general. (TW)

  19. Bed-exit alarm effectiveness

    Science.gov (United States)

    Capezuti, Elizabeth; Brush, Barbara L.; Lane, Stephen; Rabinowitz, Hannah U.; Secic, Michelle

    2009-01-01

    This study describes the accuracy of two types of bed-exit alarms to detect bed-exiting body movements: pressure-sensitive and a pressure sensitive combined with infrared beam detectors (dual sensor system). We also evaluated the occurrence of nuisance alarms, or alarms that are activated when a participant does not attempt to get out of bed. Fourteen nursing home residents were directly observed for a total of 256 nights or 1,636.5 hours; an average of 18.3 ± 22.3 (± S.D.) nights/participant for an average of 6.4 ± 1.2 hours/night. After adjusting for body movements via repeated measures, Poisson regression modeling, the least squares adjusted means show a marginally significant difference between the type of alarm groups on the number of true positives (mean/S.E.M. = 0.086/1.617) for pressure-sensitive vs. dual sensor alarm (0.593/1.238; p = 0.0599) indicating that the dual sensor alarm may have a higher number of true positives. While the dual sensor bed-exit alarm was more accurate than the pressure sensitive alarm in identifying bed-exiting body movements and reducing the incidence of false alarms, false alarms were not eliminated altogether. Alarms are not a substitute for staff; adequate staff availability is still necessary when residents need or wish to exit bed. PMID:18508138

  20. Northern European Satellite Test Bed

    Science.gov (United States)

    Schuster-Bruce, Alan; Lawson, James; Quinlan, Michael; McGregor, Andrew

    Satellite Based Augmentation Systems are being developed in Europe (EGNOS), the USA (WAAS), and in Japan (MSAS). As part of their support to EGNOS, NATS and Racal have developed and deployed a prototype SBAS system called the Northern European Satellite Test Bed (NEST Bed). NEST Bed uses GPS L1/L2 reference stations at: Aberdeen, Rotterdam, Ankara, Cadiz, Keflavik, and Bronnoysund. Data is sent to the Master Control Centre at NATS Gatwick Services Management Centre for processing. The resulting 250 bits-per-second message is sent to Goonhilly for up-linking by BT to the Navigation Payload of either the Inmarsat AOR-E or F5 spare satellite. NEST Bed was deployed and commissioned during summer 1998, and flight tests were successfully demonstrated at the September 1998 Farnborough Air Show where approaches were flown to Boscombe Down on the DERA BAC1-11 aircraft. In October 1998, a NATS/FAA flight trial was held in Iceland involving NEST Bed and the FAA NSTB. NEST Bed is also being used for SARPS validation.

  1. Effects of coal storage in air on physical and chemical properties of coal and on gas adsorption

    Science.gov (United States)

    Mastalerz, Maria; Solano-Acosta, W.; Schimmelmann, A.; Drobniak, A.

    2009-01-01

    This paper investigates changes in the high-volatile bituminous Lower Block Coal Member from Indiana owing to moisture availability and oxidation in air at ambient pressure and temperature over storage time. Specifically, it investigates changes in chemistry, in surface area, and pore structure, as well as changes in methane and carbon dioxide adsorption capacities. Our results document that the methane adsorption capacity increased by 40%, whereas CO2 adsorption capacity increased by 18% during a 13-month time period. These changes in adsorption are accompanied by changes in chemistry and surface area of the coal. The observed changes in adsorption capacity indicate that special care must be taken when collecting samples and preserving coals until adsorption characteristics are measured in the laboratory. High-pressure isotherms from partially dried coal samples would likely cause overestimation of gas adsorption capacities, lead to a miscalculation of coal-bed methane prospects, and provide deceptively optimistic prognoses for recovery of coal-bed methane or capture of anthropogenic CO2. ?? 2009 Elsevier B.V. All rights reserved.

  2. Woody waste air gasification in fluidized bed with Ca- and Mg-modified bed materials and additives

    International Nuclear Information System (INIS)

    This study focuses on the promotion of biomass gasification for hydrogen production in a fluidized bed reactor with the bed additives zeolite, CaO, and Ca- and Mg-based silica sands. The results show that zeolite has higher capacity for enhancing hydrogen promotion abilities than CaO with the amount was 200 g in tests. Regarding the Ca- and Mg-based silica sands, Ca/SiO2 decreases the CO2 selectivity and Mg/SiO2 enhances the H2 selectivity owing to CO2 adsorption via the formation of CaO and the promotion of the water gas shift reaction, respectively. The optimal concentration of Mg-based bed materials corresponds to a Mg concentration of 0.5 wt.%. The additives play important roles in increasing the reaction rate, enhancing the biomass gasification, and promoting carbon transformation. -- Graphical abstract: The aim of this study is not only in estimation of the influence of the alkaline metals concentrations, but also in preparation of the modified fluidization mediums. A basic stoichiometric analysis of alkaline concentration for hydrogen production during biomass gasification in fluidized bed is also in consideration. Highlights: ► Various bed-additives concentrations on syngas performance are discussed. ► All additives significantly increase rate of hydrogen production in gasification. ► Zeolite has higher capacity for enhancing hydrogen production rate than CaO. ► Ca-based additives promoted the heating value and cold gas efficiency. ► The optimal concentration of Mg-based additive was 0.5 wt.% for hydrogen production

  3. 49 CFR 236.336 - Locking bed.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking bed. 236.336 Section 236.336 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Instructions § 236.336 Locking bed. The various parts of the locking bed, locking bed supports, and tappet...

  4. Enhancing activated carbon adsorption of 2-methylisoborneol: methane and steam treatments

    Energy Technology Data Exchange (ETDEWEB)

    Kirk O. Nowack; Fred S. Cannon; David W. Mazyck [Pennsylvania State University, University Park, PA (United States). Department of Civil and Environmental Engineering

    2004-01-01

    This research investigated methods for tailoring a commercial, lignite-based granular activated carbon (GAC) to enhance its adsorption of 2-methylisoborneol (MIB) from natural water. Tailoring efforts focused on heat treatments in gas environments comprising steam and/or methane, since these gases can alter GAC pore structure and surface chemistry. Heat treatments that combined methane and steam enhanced MIB adsorption considerably, causing a 4-fold improvement (over untreated GAC) in fixed-bed adsorption performance relative to initial MIB breakthrough. These favorable effects, observed in rapid small-scale column tests, occurred following simultaneous and separate (sequential) applications of methane and steam. Moderately low temperature steam treatments also improved MIB uptake in fixed-bed adsorption tests but to a lesser extent (approximately 1.5-fold). In contrast, methane treatments alone, at various temperatures, led to significant carbon deposition within the GAC pore structure. As a result, total pore volume was reduced and MIB adsorption performance declined. 62 refs., 9 figs., 2 tabs.

  5. Improved utilization of desiccant material in packed bed dehumidifier using composite particles

    Energy Technology Data Exchange (ETDEWEB)

    Ramzy K., A.; Kadoli, R.; Ashok Babu, T.P. [Mechanical Engineering Department, NITK Surathkal, Mangalore, Karnataka (India)

    2011-02-15

    Solid desiccant dehumidifiers are widely used in drying processes. In most of these dehumidifiers, the desiccant material is used as packed bed of granule or spherical particles. Investigations of intra-particle heat and mass transfer processes has shown that the entire portion of the particle is not participating effectively during adsorption as well as desorption processes [Pesaran AA, Mills F. Moisture transport in silica gel packed beds-I. Theoretical study. International Journal of Heat and Mass Transfer 1987; 30: 1037-49]. This is because the diffusion rate is very small compared to that of convection. In the present work, a new desiccant composite particle, in which the unutilized portion of the spherical desiccant particle is replaced with an inert particle, is proposed. By replacing the conventional particles with composite particles for the same mass of desiccant material, the available area for heat and mass transfer increases and more amount of desiccant material is effectively utilized. Further, in order to ascertain the improvement in the performance of the desiccant bed using the composite particles, various factors like thermo-physical properties of the inert material, composite particle thickness ratio, bed configuration, bed volume, the pressure drop and the increase in total adsorbed or desorbed mass have to be considered. In view of this, a theoretical investigation of the operation of vertical solid desiccant packed bed dehumidifier, using both conventional silica gel particles as well as the new proposed composite silica gel particles has been reported. A modified solid side resistance (MSSR) model is developed for the prediction of intra-particle temperature and water content profiles. Results of the present theoretical models, when applied to packed bed of conventional silica gel particles, agree well with the experimental results from the literature for both desorption and adsorption processes. From the theoretical results, more utilization

  6. Americium and plutonium separation by extraction chromatography for determination by accelerator mass spectrometry.

    Science.gov (United States)

    Kazi, Zakir H; Cornett, Jack R; Zhao, Xaiolei; Kieser, Liam

    2014-06-01

    A simple method was developed to separate Pu and Am using single column extraction chromatography employing N,N,N',N'-tetra-n-octyldiglycolamide (DGA) resin. Isotope dilution measurements of Am and Pu were performed using accelerator mass spectrometry (AMS) and alpha spectrometry. For maximum adsorption Pu was stabilized in the tetra valent oxidation state in 8M HNO3 with 0.05 M NaNO2 before loading the sample onto the resin. Am(III) was adsorbed also onto the resin from concentrated HNO3, and desorbed with 0.1 M HCl while keeping the Pu adsorbed. The on-column reduction of Pu(IV) to Pu(III) with 0.02 M TiCl3 facilitated the complete desorption of Pu. Interferences (e.g. Ca(2+), Fe(3+)) were washed off from the resin bed with excess HNO3. Using NdF3, micro-precipitates of the separated isotopes were prepared for analysis by both AMS and alpha spectrometry. The recovery was 97.7±5.3% and 95.5±4.6% for (241)Am and (242)Pu respectively in reagents without a matrix. The recoveries of the same isotopes were 99.1±6.0 and 96.8±5.3% respectively in garden soil. The robustness of the method was validated using certified reference materials (IAEA 384 and IAEA 385). The measurements agree with the certified values over a range of about 1-100 Bq kg(-1). The single column separation of Pu and Am saves reagents, separation time, and cost. PMID:24856406

  7. Adsorption and desorption of mixtures of organic vapors on beaded activated carbon.

    Science.gov (United States)

    Wang, Haiyan; Jahandar Lashaki, Masoud; Fayaz, Mohammadreza; Hashisho, Zaher; Philips, John H; Anderson, James E; Nichols, Mark

    2012-08-01

    In this study, adsorption and desorption of mixtures of organic compounds commonly emitted from automotive painting operations were experimentally studied. A mixture of two alkanes and a mixture of eight organic compounds were adsorbed onto beaded activated carbon (BAC) and then thermally desorbed under nitrogen. Following both adsorption and regeneration, samples of the BAC were chemically extracted. Gas chromatography-mass spectrometry (GC-MS) was used to quantify the compounds in the adsorption and desorption gas streams and in the BAC extracts. In general, for both adsorbate mixtures, competitive adsorption resulted in displacing low boiling point compounds by high boiling point compounds during adsorption. In addition to boiling point, adsorbate structure and functionality affected adsorption dynamics. High boiling point compounds such as n-decane and 2,2-dimethylpropylbenzene were not completely desorbed after three hours regeneration at 288 °C indicating that these two compounds contributed to heel accumulation on the BAC. Additional compounds not present in the mixtures were detected in the extract of regenerated BAC possibly due to decomposition or other reactions during regeneration. Closure analysis based on breakthrough curves, solvent extraction of BAC and mass balance on the reactor provided consistent results of the amount of adsorbates on the BAC after adsorption and/or regeneration. PMID:22742925

  8. Adsorption on Mesoporous Metal-Organic Frameworks in Solution: Aromatic and Heterocyclic Compounds.

    Science.gov (United States)

    Samokhvalov, Alexander

    2015-11-16

    Adsorption and desorption play major roles in separations, purification of water, waste streams, liquid fuels, catalysis, biomedicine and chromatography. Mesoporous metal-organic frameworks (MOFs) with pore sizes 2-50 nm are particularly suitable for adsorption of organic compounds in solution. Tens of thousands of aromatic and heterocyclic compounds are major components of liquid fuels, feedstock for industrial synthesis, solvents, dyestuffs, agricultural chemicals, medicinal drugs, food additives, and so forth. This Review provides a systematization and analysis of studies on adsorption/desorption on mesoporous MOFs in solution and their underlying chemical mechanisms. The (in)stability of mesoporous MOFs in water is critically discussed. Adsorption capacity and selectivity are covered for organic dyes, medicinal drugs, major components of liquid fuels, and miscellaneous industrial chemicals. Ionic interactions, Brønsted acid-base interactions, hydrogen bonding, coordination bonding, π-π interactions, and non-specific interactions are covered amongst adsorption mechanisms. The effects of post-synthetic modifications of mesoporous MOFs on their stability, adsorption capacity, selectivity, and mechanisms of adsorption and desorption are analyzed. To encourage research in this quickly growing field, we identify "niches" for which no application-oriented and/or mechanistic studies were reported. Perspectives and limitations of a wide use of mesoporous MOFs as industrial sorbents are discussed.

  9. Experimental study on dynamic gas adsorption

    Institute of Scientific and Technical Information of China (English)

    Qin Yueping; Wang Yaru; Yang Xiaobin; Liu Wei; Luo Wei

    2012-01-01

    In order to predict the actual adsorption amount as gas adsorption reaches the equilibrium,this research designed a dynamic gas adsorption experiment under constant temperature and pressure,and also studied the isopiestic adsorption characteristics of coal samples with same quality but different sizes.Through the experiment,the study found the adsorption-time changing relationships under different pressures of four different size samples.After regression analysis,we obtained the functional relationship between adsorption and time.According to this,the research resulted in the actual adsorption amount when gas adsorption reaches the equilibrium.In addition,the current study obtained the relationship between adsorption and pressure as well as the effect of the coal size to the adsorption rate.These results have great theoretical and practical significance for the prediction of gas amount in coal seam and gas adsorption process.

  10. Size fractionation by slalom chromatography and hydrodynamic chromatography

    OpenAIRE

    Ricardo P. Dias

    2008-01-01

    Hydrodynamic chromatography, also called separation by flow, is based on the use of the parabolic flow profile occurring in open capillaries or in the pores from a column filled with non-porous particles. The hydrodynamic chromatography separation medium, if any, is much simpler than that from size exclusion chromatography (porous particles), the former technique being used in the size-fractionation of many colloids and macromolecules. The transition between hydrodynamic chromatography (obtai...

  11. Adsorption of Atenolol on Kaolinite

    Directory of Open Access Journals (Sweden)

    Yingmo Hu

    2015-01-01

    Full Text Available In this study the adsorption of atenolol (AT, a β-blocker, on kaolinite, a clay mineral of low surface charge, was investigated under varying initial AT concentration, equilibrium time, solution pH, ionic strength, and temperature conditions. The results showed that the amounts of AT uptake by kaolinite were close to its cation exchange capacity value and the AT adsorption was almost instantaneous, suggesting a surface adsorption. The adsorption was exothermic and the free energy of adsorption was small negative, indicating physical adsorption. The increase in ionic strength of the solution drastically reduced AT uptake on kaolinite. A significant reduction in AT uptake was found at solution pH below 5 or above 10. The FTIR results showed band shifting and disappearance for NH bending vibration and benzene ring skeletal vibration at 3360 and 1515 cm−1 and band splitting at 1412 and 1240 cm−1 attributed to C–N valence vibration coupled with NH bending vibrations and alkyl aryl ether linkage, suggesting the participation of NH, –O–, and benzene ring for AT adsorption on kaolinite.

  12. Adsorption Desalination: A Novel Method

    KAUST Repository

    Ng, Kim Choon

    2010-11-15

    The search for potable water for quenching global thirst remains a pressing concern throughout many regions of the world. The demand for new and sustainable sources and the associated technologies for producing fresh water are intrinsically linked to the solving of potable water availability and hitherto, innovative and energy efficient desalination methods seems to be the practical solutions. Quenching global thirst by adsorption desalination is a practical and inexpensive method of desalinating the saline and brackish water to produce fresh water for agriculture irrigation, industrial, and building applications. This chapter provides a general overview of the adsorption fundamentals in terms of adsorption isotherms, kinetics, and heat of adsorption. It is then being more focused on the principles of thermally driven adsorption desalination methods. The recent developments of adsorption desalination plants and the effect of operating conditions on the system performance in terms of specific daily water production and performance ratio are presented. Design of a large commercial adsorption desalination plant is also discussed herein.

  13. Optimizing heterosurface adsorbent synthesis for liquid chromatography

    Science.gov (United States)

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

    2016-03-01

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

  14. UNIFIED THEORETICAL MOMENT EXPRESSIONS FOR ELUTION CHROMATOGRAPHY AND FRONTAL CHROMATOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    YANGGengliang; TAOZuyi

    1992-01-01

    The unified theoretical moment expressions for elution chromatography and frontal chromatography when the sorption process is described by a linear model were derived. The moment expressions derived by previous authors can be obtained from these unified theoretical moment expressions. In this paper, a mathematical analysis has been carried out so as to set up a unified theoretical basis for elution and frontal chromatography.

  15. Particle motion in fluidised beds

    International Nuclear Information System (INIS)

    Gas fluidised beds are important components in many process industries, e.g. coal combustors and granulators, but not much is known about the movement of the solids. Positron Emission Particle Tracking (PEPT) enables the movement of a single, radioactive tracer particle to be followed rapidly and faithfully. Experiments were carried out in columns sized between 70 and 240mm. diameter, operating in the bubbling regime at ambient process conditions using particles of group B and D (Geldart Classification). Particle motion was tracked and the data applied to models for particle movement at the gas distributor as well as close to other surfaces and to models for particle circulation in beds of cohesive particles. In the light of these data, models for particle and bubble interaction, particle circulation, segregation, attrition, erosion, heat transfer and fluidised bed scale-up rules were reassessed. Particle motion is directly caused by bubble motion, and their velocities were found to be equal for particles travelling in a bubble. PEPT enables particle circulation to be measured, giving a more accurate correlation for future predictions. Particle motion follows the scale-up rules based on similarities of the bubble motion in the bed. A new group of parameters was identified controlling the amount of attrition in fluidised beds and a new model to predict attrition is proposed. (author)

  16. Breakthrough curves of oil adsorption on novel amorphous carbon thin film.

    Science.gov (United States)

    El-Sayed, M; Ramzi, M; Hosny, R; Fathy, M; Abdel Moghny, Th

    2016-01-01

    A novel amorphous carbon thin film (ACTF) was prepared by hydrolyzing wood sawdust and delignificating the residue to obtain cellulose mass that was subjected to react with cobalt silicate nanoparticle as a catalyst under the influence of sudden concentrated sulfuric acid addition at 23 °C. The novel ACTF was obtained in the form of thin films like graphene sheets having winding surface. The prepared ACTF was characterized by Fourier-transform infrared spectrometer, transmission electron microscope (TEM), and Brunauer-Emmett-Teller (BET). The adsorption capacity of ACTF to remove oil from synthetic produced water was evaluated using the incorporation of Thomas and Yoon-Nelson models. The performance study is described through the breakthrough curves concept under relevant operating conditions such as column bed heights (3.8, 5 and 11 mm) and flow rate (0.5, 1 and 1.5 mL.min(-1)). It was found that the oil uptake mechanism is favoring higher bed height. Also, the highest bed capacity of 700 mg oil/g ACTF was achieved at 5 mm bed height, and 0.5 mL.min(-1) flow rate. The results of breakthrough curve for oil adsorption was best described using the Yoon-Nelson model. Finally, the results illustrate that ACTF could be utilized effectively for oil removal from synthetic produced water in a fixed-bed column system. PMID:27191556

  17. Development of a thermal storage system based on the heat of adsorption of water in hygroscopic materials

    NARCIS (Netherlands)

    Wijsman, A.J.T.M.; Oosterhaven, R.; Ouden, C. den

    1979-01-01

    A thermal storage system based on the heat of adsorption of water in hygroscopic materials has been studied as a component of a solar space heating system. The aim of this project is to decrease the storage volume in comparison with a rock-bed storage system by increasing the stored energy density.

  18. Carbon nanomaterials for gas adsorption

    CERN Document Server

    Terranova, Maria Letizia

    2012-01-01

    Research in adsorption of gases by carbon nanomaterials has experienced considerable growth in recent years, with increasing interest for practical applications. Many research groups are now producing or using such materials for gas adsorption, storage, purification, and sensing. This book provides a selected overview of some of the most interesting scientific results regarding the outstanding properties of carbon nanomaterials for gas adsorption and of interest both for basic research and technological applications. Topics receiving special attention in this book include storage of H, purific

  19. Modern Thin-Layer Chromatography.

    Science.gov (United States)

    Poole, Colin F.; Poole, Salwa K.

    1989-01-01

    Some of the important modern developments of thin-layer chromatography are introduced. Discussed are the theory and instrumentation of thin-layer chromatography including multidimensional and multimodal techniques. Lists 53 references. (CW)

  20. Extending Paper Chromatography Inquiry

    Science.gov (United States)

    Finson, Kevin

    2004-01-01

    One of the "good old" standard activities middle school students seem to enjoy is paper chromatography. The procedures and materials needed are relatively simple and the results can be colorful. All too often, the activity ends just after these colorful results are obtained, cutting short the potential it holds for some further inquiry. With some…

  1. Continuous adsorption and recovery of Cr(VI) in different types of reactors.

    Science.gov (United States)

    Bai, Sudha R; Abraham, T Emilia

    2005-01-01

    This study reports the results of experiments on continuous adsorption and desorption of Cr(VI) ions by a chemically modified and polysulfone-immobilized biomass of the fungus Rhizopus nigricans. A fixed quantity of polymer-entrapped biomass beads corresponding to 2 g of dry biomass powder was employed in packed bed, fluidized bed, and stirred tank reactor for monitoring the continuous removal and recovery of Cr(VI) ions from aqueous solution and synthetic chrome plating effluent. Parameters such as flow rate (5, 10 and 15 mL/min), inlet concentration of Cr(VI) ions (50, 100, 150 and 250 mg/L) and the depth of biosorbent packing (22.8, 11.2 and 4.9 cm) were evaluated for the packed bed reactor. The breakthrough time and the adsorption rates in the packed bed column were found to decrease with increasing flow rate and higher Cr inlet concentrations and to increase with higher depths of sorbent packing. To have a comparative analysis of Cr adsorption efficiency in different types of reactors, the fluidized bed reactor and stirred tank reactor were operated using the same quantities of biosorbent material. For the fluidized bed reactor, Cr(VI) solution of 100 mg/L was pumped at 5 mL/min and fluidized by compressed air at a flow rate of 0.5 kg/cm.(2) The stirred tank reactor had a working volume of 200 mL capacity and the inlet/outlet flow rate was 5 mL/min. The maximum removal efficiency (mg Cr/g biomass) was obtained for the stirred tank reactor (159.26), followed by the fluidized reactor (153.04) and packed bed reactor (123.33). In comparison to the adsorption rate from pure chromate solution, approximately 16% reduction was monitored for synthetic chrome plating effluent in the packed bed. Continuous desorption of bound Cr ions from the reactors was effective with 0.01 N Na(2)CO(3) and nearly 80-94% recoveries have been obtained for all the reactors. PMID:16321053

  2. Designing a CR Test bed

    DEFF Research Database (Denmark)

    Cattoni, Andrea Fabio; Buthler, Jakob Lindbjerg; Tonelli, Oscar;

    2014-01-01

    Research on intelligent and reconfigurable wireless systems is in continuous evolution. Nevertheless, in order to fix some keystones, more and more researchers are entering the idea of research-oriented test beds. Unfortunately, it is very difficult for a wide number of research groups to start...... with their own set up, since the potential costs and efforts could not pay back in term of expected research results. Software Defined Radio solutions offer an easy way to communication researchers for the development of customized research test beds. While several hardware products are commercially available...... they are up and running in generating results. With this chapter we would like to provide a tutorial guide, based on direct experience, on how to enter in the world of test bed-based research, providing both insight on the issues encountered in every day development, and practical solutions. Finally...

  3. Experimental investigation of CO{sub 2} capture using sodium hydroxide particles in a fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Naeem, Sareh; Ghaemi, Ahad; Shahhosseini, Shahrokh [Iran University of Science and Technology (IUST), Tehran (Iran, Islamic Republic of)

    2016-04-15

    CO{sub 2} capture from air using sodium hydroxide solid sorbent in a laboratory scale fluidized bed reactor was investigated experimentally. The influence of three parameters of temperature, inlet CO{sub 2} volume percentage and inlet air flow rate on the CO{sub 2} removal rate was studied. Experimental results showed that the optimum rate was at 25 oC when the inlet CO{sub 2} volume percentage was 1%. The results also showed that the adsorption process was reactive, and the reaction mechanism depended on the reaction temperature. In addition, empirical observation revealed only one adsorption cycle happened at low temperatures (25-30 oC). As the temperature increased, the second adsorption cycle occurred and, finally, CO{sub 2} desorption cycle took place in the range of 90-115 .deg. C.

  4. Color removal from textile dyebath effluents in a zeolite fixed bed reactor: Determination of optimum process conditions using Taguchi method

    International Nuclear Information System (INIS)

    Taguchi method was applied as an experimental design to determine optimum conditions for color removal from textile dyebath house effluents in a zeolite fixed bed reactor. After the parameters were determined to treat real textile wastewater, adsorption experiments were carried out. The breakthrough curves for adsorption studies were constructed under different conditions by plotting the normalized effluent color intensity (C/C0) versus time (min) or bed volumes (BV). The chosen experimental parameters and their ranges are: HTAB concentration (Chtab), 1-7.5 g L-1; HTAB feeding flowrate (Qhtab), 0.015-0.075 L min-1; textile wastewater flowrate (Qdye), 0.025-0.050 L min-1 and zeolite bed height (Hbed), 25-50 cm, respectively. Mixed orthogonal array L16 (42 x 22) for experimental plan and the larger the better response category were selected to determine the optimum conditions. The optimum conditions were found to be as follows: HTAB concentration (Chtab) = 1 g L-1, HTAB feeding flowrate (Qhtab) = 0.015 L min-1, textile wastewater flowrate (Qdye) = 0.025 L min-1 and bed height (Hbed) = 50 cm. Under these conditions, the treated wastewater volume reached a maximum while the bed volumes (BV) were about 217. While HTAB concentration, g L-1 (A); zeolite bed height, cm (D) and wastewater flowrate, L min-1 (C) were found to be significant parameters, respectively, whereas, HTAB flowrate, L min-1 (B) was found to be an insignificant parameter

  5. Effects of temperature and volumetric loading rate on phenol adsorption capacity by granular activated carbon

    Directory of Open Access Journals (Sweden)

    Bamrungsri, P.

    2004-02-01

    Full Text Available The effects of temperature and volumetric loading rate on adsorption capacity of phenol by granular activated carbon were studied using F-300 and C2-115 granular activated carbon. All the experiments were conducted both in a batch study and a fixed-bed adsorption column study with the initial phenol concentration of 10 mg/l. In the batch study, the effects of temperature on the adsorption capacity and the rate of adsorption were determined. The results from the batch study showed that the rate of adsorption of F-300 was higher than that of C2-115. Moreover, it was clearly shown that the adsorption capacity increased with increasing temperature in both types of activated carbon at a contact time of 5 hours. In addition, the results from the fixed-bed column study revealed that the adsorption capacity decreased with increasing volumetric loading rate. Regression analysis expressed that the constants of Bohart-Adams Model ( K at volumetric loading rate of 2.5 , 5.0 and 10.0 m3/m2-hr were 0.0027 , 0.0063 and 0.0128 l/mg-hr for F-300 and 0.0021, 0.0071 and 0.0127 l/mg-hr for C2-115, respectively. N0 constant at volumetric loading rates of 2.5, 5.0 and 10.0 m3/ m2-hr were 30,393, 19,502 and 13,997 mg/l for F-300 and 27,752, 13,873 and 10,535 mg/l for C2-115, respectively. Thus, it can be summarized that the performance of F-300 was higher than that of C2-115 activated carbon at the studied conditions.

  6. Adsorption of aniline, phenol, and chlorophenols on pure and modified bentonite

    Science.gov (United States)

    Yildiz, A.; Gür, A.; Ceylan, H.

    2006-11-01

    In the present study, pure bentonite and bentonite modified by HNO3, EDTA, and HDTMA are adsorbents. The changes on the surfaces of bentonite samples are studied by IR spectroscopy. The adsorption of aniline, phenol, and phenol derivatives on these adsorbents is examined by means of gas chromatography. As the result of these examinations, it is seen that the adsorption capacities of clay-organic complexes (bentonite-EDTA and bentonite-HDTMA) are higher than those of bentonite-HNO3 and pure bentonite.

  7. Experimental and numerical investigations on the performance of dehumidifying desiccant beds composed of silica-gel and thermal energy storage particles

    Science.gov (United States)

    Rady, M. A.

    2009-03-01

    Enhanced efficiency of the adsorption process in the dehumidifier is a key element for improved performance of desiccant cooling systems. Due to the exothermic nature of the adsorption process, the dehumidification and cooling capacity are limited by significant temperature changes in the adsorption column. In the present study, the effects of integration of sensible and latent heat storage particles in the desiccant bed for in situ management of released adsorption heat are investigated. For this purpose, column experiments are performed using an initially dry granular bed made of silica-gel particles or a homogeneous mixture of silica gel and inert sensible or latent heat storage particles. The packed bed is subject to a sudden uniform air flow at selected values of temperature and humidity. Also, a packed bed numerical model is developed that includes the coupled non-equilibrium heat and moisture transfer in the solid and gas phases. Investigations of the heat and mass transfer characteristics are reported using the composite structure and the results are compared with the base case of simple silica gel bed. Improved desiccant cooling system performance can be obtained by appropriate adjustment of desiccant cycle operation and proper choice of the volume ratio of thermal energy storage particles.

  8. High Performance Thin Layer Chromatography.

    Science.gov (United States)

    Costanzo, Samuel J.

    1984-01-01

    Clarifies where in the scheme of modern chromatography high performance thin layer chromatography (TLC) fits and why in some situations it is a viable alternative to gas and high performance liquid chromatography. New TLC plates, sample applications, plate development, and instrumental techniques are considered. (JN)

  9. Potential Theory of Multicomponent Adsorption

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Stenby, Erling Halfdan

    1998-01-01

    We developed a theory of multicomponent adsorption on the basis of the potential concept originally suggested by Polanyi. The mixture is considered as a heterogeneous substance segregated in the external field emitted by the adsorbent. The same standard equation of state, with no additional fitting...... parameters, is used for the segregated and for the bulk phases. With this approach, few parameters are needed to correlate pure component adsorption isotherms. These parameters may be used to predict adsorption equilibria of multicomponent mixtures without additional adjustment. A connection between...... the potential theory and the spreading pressure concept is established, and problems of the theory consistency are studied. Numerical algorithms are suggested for evaluation of the segregated state of the mixture in the potential field of adsorption forces. Comparison with experimental data shows good agreement...

  10. Prediction of Pure Component Adsorption Equilibria Using an Adsorption Isotherm Equation Based on Vacancy Solution Theory

    DEFF Research Database (Denmark)

    Marcussen, Lis; Aasberg-Petersen, K.; Krøll, Annette Elisabeth

    2000-01-01

    An adsorption isotherm equation for nonideal pure component adsorption based on vacancy solution theory and the Non-Random-Two-Liquid (NRTL) equation is found to be useful for predicting pure component adsorption equilibria at a variety of conditions. The isotherm equation is evaluated successfully...... adsorption systems, spreading pressure and isosteric heat of adsorption are also calculated....

  11. Enhancement of anion-exchange chromatography of DNA using compaction agents

    Science.gov (United States)

    Murphy, Jason C.; Fox, George E.; Willson, Richard C.

    2003-01-01

    The use of adsorptive chromatography for preparative nucleic acid separations is often limited by low capacity. The possibility that the adsorbent surface area sterically accessible to nucleic acid molecules could be increased by reducing their radius of gyration with compaction agents has been investigated. The equilibrium adsorption capacity of Q Sepharose anion-exchange matrix for plasmid DNA at 600 mM NaCl was enhanced by up to ca. 40% in the presence of 2.5 mM spermine. In addition, compaction agent selectivity has been demonstrated. Spermine, for example, enhances the adsorption of both plasmid and genomic DNA, spermidine enhances binding only of plasmid, and hexamine cobalt enhances only the binding of genomic DNA. Compaction may be generally useful for enhancing adsorptive separations of nucleic acids.

  12. Molecular adsorption on graphene

    Science.gov (United States)

    Kong, Lingmei; Enders, Axel; Rahman, Talat S.; Dowben, Peter A.

    2014-11-01

    Current studies addressing the engineering of charge carrier concentration and the electronic band gap in epitaxial graphene using molecular adsorbates are reviewed. The focus here is on interactions between the graphene surface and the adsorbed molecules, including small gas molecules (H2O, H2, O2, CO, NO2, NO, and NH3), aromatic, and non-aromatic molecules (F4-TCNQ, PTCDA, TPA, Na-NH2, An-CH3, An-Br, Poly (ethylene imine) (PEI), and diazonium salts), and various biomolecules such as peptides, DNA fragments, and other derivatives. This is followed by a discussion on graphene-based gas sensor concepts. In reviewing the studies of the effects of molecular adsorption on graphene, it is evident that the strong manipulation of graphene’s electronic structure, including p- and n-doping, is not only possible with molecular adsorbates, but that this approach appears to be superior compared to these exploiting edge effects, local defects, or strain. However, graphene-based gas sensors, albeit feasible because huge adsorbate-induced variations in the relative conductivity are possible, generally suffer from the lack of chemical selectivity.

  13. Protein Adsorption in Three Dimensions

    OpenAIRE

    Vogler, Erwin A.

    2011-01-01

    Recent experimental and theoretical work clarifying the physical chemistry of blood-protein adsorption from aqueous-buffer solution to various kinds of surfaces is reviewed and interpreted within the context of biomaterial applications, especially toward development of cardiovascular biomaterials. The importance of this subject in biomaterials surface science is emphasized by reducing the “protein-adsorption problem” to three core questions that require quantitative answer. An overview of the...

  14. Amphiphile Adsorption on Rigid Polyelectrolytes

    OpenAIRE

    Kuhn, Paulo S.; Levin, Yan; Barbosa, Marcia C.; Ravazzolo, Ana Paula

    2007-01-01

    A theory is presented which quantitatively accounts for the cooperative adsorption of cationic surfactants to anionic polyelectrolytes. For high salt concentration we find that the critical adsorption concentration (CAC) is a bilinear function of the polyion monomer and salt concentrations, with the coefficients dependent only on the type of surfactant used. The results presented in the paper might be useful for designing more efficient gene delivery systems.

  15. Americium and plutonium separation by extraction chromatography for determination by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kazi, Zakir H. [Department of Earth Science, University of Ottawa, 140 Louis Pasteur Avenue, Ottawa K1N 6N5 (Canada); Cornett, Jack R., E-mail: jack.cornett@uottawa.ca [Department of Earth Science, University of Ottawa, 140 Louis Pasteur Avenue, Ottawa K1N 6N5 (Canada); Zhao, Xaiolei; Kieser, Liam [Department of Physics, University of Ottawa, 140 Louis Pasteur Avenue, Ottawa K1N 6N5 (Canada)

    2014-06-01

    Highlights: • Am and Pu were adsorbed and separated using a single extraction chromatography DGA column. • Pu was eluted from the column completely using on-column reduction of Pu(IV) to Pu(III). • ²⁴¹Am and 239,240Pu measurements by accelerator mass spectrometry (AMS) agree with the certified values in two SRMs. Abstract: A simple method was developed to separate Pu and Am using single column extraction chromatography employing N,N,N',N'-tetra-n-octyldiglycolamide (DGA) resin. Isotope dilution measurements of Am and Pu were performed using accelerator mass spectrometry (AMS) and alpha spectrometry. For maximum adsorption Pu was stabilized in the tetra valent oxidation state in 8 M HNO₃ with 0.05 M NaNO₂ before loading the sample onto the resin. Am(III) was adsorbed also onto the resin from concentrated HNO₃, and desorbed with 0.1 M HCl while keeping the Pu adsorbed. The on-column reduction of Pu(IV) to Pu(III) with 0.02 M TiCl₃ facilitated the complete desorption of Pu. Interferences (e.g. Ca²⁺, Fe³⁺) were washed off from the resin bed with excess HNO₃. Using NdF₃, micro-precipitates of the separated isotopes were prepared for analysis by both AMS and alpha spectrometry. The recovery was 97.7 ± 5.3% and 95.5 ± 4.6% for ²⁴¹Am and ²⁴²Pu respectively in reagents without a matrix. The recoveries of the same isotopes were 99.1 ± 6.0 and 96.8 ± 5.3% respectively in garden soil. The robustness of the method was validated using certified reference materials (IAEA 384 and IAEA 385). The measurements agree with the certified values over a range of about 1–100 Bq kg⁻¹. The single column separation of Pu and Am saves reagents, separation time, and cost.

  16. Numerical Simulation and Experimental Study of Deep Bed Corn Drying Based on Water Potential

    Directory of Open Access Journals (Sweden)

    Zhe Liu

    2015-01-01

    Full Text Available The concept and the model of water potential, which were widely used in agricultural field, have been proved to be beneficial in the application of vacuum drying model and have provided a new way to explore the grain drying model since being introduced to grain drying and storage fields. Aiming to overcome the shortcomings of traditional deep bed drying model, for instance, the application range of this method is narrow and such method does not apply to systems of which pressure would be an influential factor such as vacuum drying system in a way combining with water potential drying model. This study established a numerical simulation system of deep bed corn drying process which has been proved to be effective according to the results of numerical simulation and corresponding experimental investigation and has revealed that desorption and adsorption coexist in deep bed drying.

  17. ADSORPTION OF POLYCHLORINATED BIPHENYLS BY SOILS

    OpenAIRE

    Mihaela Preda; Radu Lăcătuşu; Dumitru Marian Motelică; Nicoleta Vrînceanu; Veronica Tănase

    2010-01-01

    The behavior of polychlorinated biphenyls (PCBs) in soil is determined by several factors including adsorption, mobility and degradation. Adsorption, directly or indirectly, influences the other factors. Adsorption process is generally evaluated by using adsorption isotherms representing the relationship between the quantity of substance adsorbed per unit weight and concentration of the substance in solution at equilibrium. They allow determination of the adsorption constant, which is directl...

  18. Adsorption refrigeration technology theory and application

    CERN Document Server

    Wang, Ruzhu; Wu, Jingyi

    2014-01-01

    Gives readers a detailed understanding of adsorption refrigeration technology, with a focus on practical applications and environmental concerns Systematically covering the technology of adsorption refrigeration, this book provides readers with a technical understanding of the topic as well as detailed information on the state-of-the-art from leading researchers in the field. Introducing readers to background on the development of adsorption refrigeration, the authors also cover the development of adsorbents, various thermodynamic theories, the design of adsorption systems and adsorption refri

  19. Modeling of Experimental Adsorption Isotherm Data

    OpenAIRE

    Xunjun Chen

    2015-01-01

    Adsorption is considered to be one of the most effective technologies widely used in global environmental protection areas. Modeling of experimental adsorption isotherm data is an essential way for predicting the mechanisms of adsorption, which will lead to an improvement in the area of adsorption science. In this paper, we employed three isotherm models, namely: Langmuir, Freundlich, and Dubinin-Radushkevich to correlate four sets of experimental adsorption isotherm data, which were obtained...

  20. Hierarchical Porous Zeolite Structures for Pressure Swing Adsorption Applications.

    Science.gov (United States)

    Besser, Benjamin; Tajiri, Henrique Akira; Mikolajczyk, Gerd; Möllmer, Jens; Schumacher, Thomas C; Odenbach, Stefan; Gläser, Roger; Kroll, Stephen; Rezwan, Kurosch

    2016-02-10

    Porous adsorbents with hierarchical structured macropores ranging from 1 to 100 μm are prepared using a combination of freeze casting and additional sacrificial templating of polyurethane foams, with a zeolite 13X powder serving as adsorbent. The pore system of the prepared monoliths features micropores assigned to the zeolite 13X particle framework, interparticular pores of ∼1-2 μm, lamellar pores derived from freeze casting of ∼10 μm, and an interconnected pore network obtained from the sacrificial templates ranging from around 100 to 200 μm with a total porosity of 71%. Gas permeation measurements show an increase in intrinsic permeability by a factor of 14 for monoliths prepared with an additional sacrificial templated foam compared to monoliths solely providing freeze casting pores. Cyclic CO2 adsorption and desorption tests where pressure swings between 8 and 140 kPa reveal constant working capacities over multiple cycles. Furthermore, the monoliths feature a high volumetric working capacity of ∼1.34 mmol/cm(3) which is competitive to packed beds made of commercially available zeolite 13X beads (∼1.28 mmol/cm(3)). Combined with the faster CO2 uptake showing an adsorption of 50% within 5-8 s (beads ∼10 s), the monoliths show great potential for pressure swing adsorption applications, where high volumetric working capacities, fast uptakes, and low pressure drops are needed for a high system performance. PMID:26760054

  1. Adsorption of Methyl Tertiary Butyl Ether on Granular Zeolites: Batch and Column Studies

    OpenAIRE

    Abu-Lail, Laila; Bergendahl, John A.; Thompson, Robert W

    2010-01-01

    Methyl tertiary butyl ether (MTBE) has been shown to be readily removed from water with powdered zeolites, but the passage of water through fixed beds of very small powdered zeolites produces high friction losses not encountered in flow through larger sized granular materials. In this study, equilibrium and kinetic adsorption of MTBE onto granular zeolites, a coconut shell granular activated carbon (CS-1240), and a commercial carbon adsorbent (CCA) sample was evaluated. In addition, the effec...

  2. Spin projection chromatography

    OpenAIRE

    Danieli, Ernesto P.; Pastawski, Horacio M.; Levstein, Patricia R.

    2003-01-01

    We formulate the many-body spin dynamics at high temperature within the non-equilibrium Keldysh formalism. For the simplest XY interaction, analytical expressions in terms of the one particle solutions are obtained for linear and ring configurations. For small rings of even spin number, the group velocities of excitations depend on the parity of the total spin projection. This should enable a dynamical filtering of spin projections with a given parity i.e. a Spin projection chromatography.

  3. Hydrophobic interaction chromatography

    OpenAIRE

    O'Connor, Brendan; Cummins, Phil

    2011-01-01

    Most proteins and large polypeptides have hydrophobic regions at their surface. These hydrophobic ‘patches’ are due to the presence of the side chains of hydrophobic or non-polar amino acids such as phenylalanine, tryptophan, alanine and methionine. These surface hydrophobic regions are interspersed between more hydrophilic or polar regions and the number, size and distribution of them is a specific characteristic of each protein. Hydrophobic Interaction Chromatography (HIC) is a commonly use...

  4. Spin projection chromatography

    Science.gov (United States)

    Danieli, E. P.; Pastawski, H. M.; Levstein, P. R.

    2004-01-01

    We formulate the many-body spin dynamics at high temperature within the non-equilibrium Keldysh formalism. For the simplest XY interaction, analytical expressions in terms of the one particle solutions are obtained for linear and ring configurations. For small rings of even spin number, the group velocities of excitations depend on the parity of the total spin projection. This should enable a dynamical filtering of spin projections with a given parity i.e., a spin projection chromatography.

  5. TREATMENT OF LANDFILL LEACHATE BY COUPLING COAGULATION-FLOCCULATION OR OZONATION TO GRANULAR ACTIVATED CARBON ADSORPTION.

    Science.gov (United States)

    Oloibiri, Violet; Ufomba, Innocent; Chys, Michael; Audenaert, Wim; Demeestere, Kristof; Van Hulle, Stijn W H

    2015-01-01

    A major concern for landfilling facilities is the treatment of their leachate. To optimize organic matter removal from this leachate, the combination of two or more techniques is preferred in order to meet stringent effluent standards. In our study, coagulation-flocculation and ozonation are compared as pre- treatment steps for stabilized landfill leachate prior to granular activated carbon (GAC) adsorption. The efficiency of the pre treatment techniques is evaluated using COD and UVA254 measurements. For coagulation- flocculation, different chemicals are compared and optimal dosages are determined. After this, iron (III) chloride is selected for subsequent adsorption studies due to its high percentage of COD and UVA254 removal and good sludge settle-ability. Our finding show that ozonation as a single treatment is effective in reducing COD in landfill leachate by 66% compared to coagulation flocculation (33%). Meanwhile, coagulation performs better in UVA254 reduction than ozonation. Subsequent GAC adsorption of ozonated effluent, coagulated effluent and untreated leachate resulted in 77%, 53% and 8% total COD removal respectively (after 6 bed volumes). The effect of the pre-treatment techniques on GAC adsorption properties is evaluated experimentally and mathematically using Thomas and Yoon-Nelson models. Mathematical modelling of the experimental GAC adsorption data shows that ozonation increases the adsorption capacity and break through time with a factor of 2.5 compared to coagulation-flocculation.

  6. Process modeling of in situ-adsorption of a bacterial lipase.

    Science.gov (United States)

    Millitzer, Marcus; Wenzig, Edda; Peukert, Wolfgang

    2005-12-20

    In situ adsorption, known as an in situ-roduct removal (ISPR) technique for low molecular mass bioproducts, was in this study applied to a bacterial exoenzyme proving that this method is also suitable for the separation of macromolecules like proteins. For this, adsorbent particles were added to growing cultures of Staphylococcus carnosus rec., therefore both production and adsorption occurred simultaneously in shaking flasks, stirred tank, or airlift bioreactor as the chosen types of fermenters. The exoenzyme lipase adsorbed rapidly and, after separating cells and adsorbents, desorbed in a packed bed column. Up to 85% of the produced lipase were recovered, fractions of these had been concentrated up to the factor 20 and purified up to a factor of 40 by the procedure. By using the airlift bioreactor an enhancement of biomass production was observed, but the necessity of the addition of an anti-foam reagent resulted in higher product losses in adsorption as well as in desorption. Production and adsorption kinetics have been modeled and applied to in situ-adsorption. The model was used to perform a parameter study in which the influence of biological and physical parameters as well as process parameters on discontinuous and continuous in situ-adsorption was investigated. PMID:16267849

  7. Selective Adsorption and Selective Transport Diffusion of CO2-CH4 Binary Mixture in Coal Ultramicropores.

    Science.gov (United States)

    Zhao, Yongliang; Feng, Yanhui; Zhang, Xinxin

    2016-09-01

    The adsorption and diffusion of the CO2-CH4 mixture in coal and the underlying mechanisms significantly affect the design and operation of any CO2-enhanced coal-bed methane recovery (CO2-ECBM) project. In this study, bituminous coal was fabricated based on the Wiser molecular model and its ultramicroporous parameters were evaluated; molecular simulations were established through Grand Canonical Monte Carlo (GCMC) and Molecular Dynamic (MD) methods to study the effects of temperature, pressure, and species bulk mole fraction on the adsorption isotherms, adsorption selectivity, three distinct diffusion coefficients, and diffusivity selectivity of the binary mixture in the coal ultramicropores. It turns out that the absolute adsorption amount of each species in the mixture decreases as temperature increases, but increases as its own bulk mole fraction increases. The self-, corrected, and transport diffusion coefficients of pure CO2 and pure CH4 all increase as temperature or/and their own bulk mole fractions increase. Compared to CH4, the adsorption and diffusion of CO2 are preferential in the coal ultramicropores. Adsorption selectivity and diffusivity selectivity were simultaneously employed to reveal that the optimal injection depth for CO2-ECBM is 800-1000 m at 308-323 K temperature and 8.0-10.0 MPa. PMID:27518119

  8. Adsorption separation of carbon dioxide from flue gas by a molecularly imprinted adsorbent.

    Science.gov (United States)

    Zhao, Yi; Shen, Yanmei; Ma, Guoyi; Hao, Rongjie

    2014-01-01

    CO2 separation by molecularly imprinted adsorbent from coal-fired flue gas after desulfurization system has been studied. The adsorbent was synthesized by molecular imprinted technique, using ethanedioic acid, acrylamide, and ethylene glycol dimethacrylate as the template, functional monomer, and cross-linker, respectively. According to the conditions of coal-fired flue gas, the influencing factors, including adsorption temperature, desorption temperature, gas flow rate, and concentrations of CO2, H2O, O2, SO2, and NO, were studied by fixed bed breakthrough experiments. The experimental conditions were optimized to gain the best adsorption performance and reduce unnecessary energy consumption in future practical use. The optimized adsorption temperature, desorption temperature, concentrations of CO2, and gas flow rate are 60 °C, 80 °C, 13%, and 170 mL/min, respectively, which correspond to conditions of practical flue gases to the most extent. The CO2 adsorption performance was nearly unaffected by H2O, O2, and NO in the flue gas, and was promoted by SO2 within the emission limit stipulated in the Chinese emission standards of air pollutants for a thermal power plant. The maximum CO2 adsorption capacity, 0.57 mmol/g, was obtained under the optimized experimental conditions, and the SO2 concentration was 150 mg/m(3). The influence mechanisms of H2O, O2, SO2, and NO on CO2 adsorption capacity were investigated by infrared spectroscopic analysis. PMID:24410306

  9. Silica nanoparticles for fines stabilization in Ottawa sand packed beds; Uso de nanopartículas de sílice para la estabilización de finos en lechos empacados de arena Ottawa

    Directory of Open Access Journals (Sweden)

    Farid Bernardo Cortes

    Full Text Available To determine the problem of fines migration on packed beds and offer a possible solution for this issue, an adsorptive system of packed beds was developed for experimental simulation of fines migration and stabilization by using silica nanoparticles. The adsorbent beds were prepared with Ottawa sand and glass spheres (average radius of 0.53 mm. Three different sand beds were used in the investigation: clean sand (water- wet system, sand submitted to a damage process using an extra-heavy Colombian crude oil (oil-wet system and sand treated with silica nanoparticles (5-15 nm. Fines suspension was prepared with alumina nanoparticles (50 nm and distilled water. Results show that beds treated with silica nanoparticles present idealized patterns for the rupture curve, indicating that silica nanoparticles capture and retain fines, decreasing fines migration due to their adsorption capacity.

  10. Fluid bed drying of guarana (Paullinia cupana HBK) extract: Effect of process factors on caffeine content

    OpenAIRE

    Pagliarussi, Renata S.; Bastos, Jairo K.; Luis A. P. Freitas

    2006-01-01

    The aim of this study was to study the convective drying of the hydroalcoholic extracts obtained from powdered guarana seeds in a spouted bed dryer. The influence of process variables, such as the convective airflow rate, extract feed rate, and air inlet temperature, on the quality of the dry extract was determined using the caffeine and moisture content for the process evaluation. The caffeine content in the alcoholic and dried extracts was determined by capillary gas chromatography. The exp...

  11. Equilibrium theory-based design of simulated moving bed processes under reduced purity requirements linear isotherms.

    Science.gov (United States)

    Rajendran, Arvind

    2008-03-28

    The design of simulated moving bed processes under reduced purity requirements for systems whose isotherm is linear is considered. Based on the equilibrium theory of chromatography, explicit equations to uniquely identify the separation region that will ensure specified extract and raffinate purities are derived. The identification of the region requires only the knowledge of Henry constants of the solutes, the concentration of the solutes in the feed and the purity specifications. These results are validated using numerical simulations. PMID:18281052

  12. Isotope effects of zinc in crown ether chromatography

    International Nuclear Information System (INIS)

    Isotope separation of zinc has been studied with a polymer-supported crown ether resin packed in glass columns. Chromatography was performed in a break-through manner by feeding a zinc chloride solution into the columns. The mass analysis revealed that the heavier isotope was enriched at the front part of the zinc adsorption band. This result means that the heavier isotopes are preferentially fractionated into the solution phase. The largest single-stage separation coefficient (ε) in the present work is 1.0 x 10-3 for the isotopic pair of 64Zn and 66Zn at 35degC. (author)

  13. Adsorption of hydrogen gas and redox processes in clays

    International Nuclear Information System (INIS)

    In order to assess the adsorption properties of hydrogen gas and reactivity of adsorbed hydrogen, we measured H2(g) adsorption on Na synthetic montmorillonite-type clays and Callovo-Oxfordian (COx) clay-rock using gas chromatography. Synthetic montmorillonites with increasing structural Fe(III) substitution (0 wt %, 3.2 wt %, and 6.4 wt % Fe) were used. Fe in the synthetic montmorillonites is principally present as structural Fe(III) ions. We studied the concomitant reduction of structural Fe(III) in the clays using 57Fe Moessbauer spectrometry. The COx, which mainly contains smectite/illite and calcite minerals, is also studied together with the pure clay fraction of this clay-rock. Experiments were performed with dry clay samples which were reacted with hydrogen gas at 90 and 120 degrees C for 30 to 45 days at a hydrogen partial pressure close to 0.45 bar. Results indicate that up to 0.11 wt % of hydrogen is adsorbed on the clays at 90 degrees C under 0.45 bar of relative pressure. Fe-57 Moessbauer spectrometry shows that up to 6% of the total structural Fe(III) initially present in these synthetic clays is reduced upon adsorption of hydrogen gas. No reduction is observed with the COx sample in the present experimental conditions. (authors)

  14. Combined paracetamol and amitriptyline adsorption to activated charcoal

    DEFF Research Database (Denmark)

    Hoegberg, Lotte Christine Groth; Groenlykke, Thor Buch; Abildtrup, Ulla;

    2010-01-01

    Objectives. High-gram drug doses seen in multiple-drug poisonings might be close to the adsorption capacity of activated charcoal (AC). The aim was to determine the maximum adsorption capacities (Q(m)) of amitriptyline and paracetamol, separately and in combination, to AC. Methods. ACs (Carbomix......® and Norit Ready-To-Use) were tested in vitro. At pH 1.2 and pH 7.2, 0.250 g AC and paracetamol and/or amitriptyline were mixed and incubated. The AC: drug ratios were 10:1, 5:1, 3:1, 2:1, and 1:1. The mixed-drug adsorption vials contained the same AC: paracetamol ratios, but amitriptyline was added as fixed...... dose (0.080 g) to all samples. Drug concentrations in the liquid phase were analyzed using high-performance liquid chromatography (HPLC)/UV-detection. Results. Q(m), amitriptyline, were 0.49 g/g Carbomix® and 0.70 g/g Norit Ready-To-Use, and Q(m), paracetamol, were 0.63 g/g Carbomix® and 0.72 g/g Norit...

  15. Overall Heat and Mass Transfer Coefficient of Water Vapor Adsorption

    Science.gov (United States)

    Hamamoto, Yoshinori; Mori, Hideo; Godo, Masazumi; Miura, Kunio; Watanabe, Yutaka; Ishizawa, Toshihiko; Takatsuka, Takeshi

    A fundamental investigation was performed to develop a compact and simple desiccant ventilation unit which is one of the main components of a novel energy saving air-conditioning system. Water vapor in the air is adsorbed and/or desorbed to be controlled the humidity of supply air through a unit of an adsorbent packed bed. A numerical simulation helps to understand the phenomena of heat and mass transfer in the bed. Overall transfer coefficients of them as properties for the simulation were estimated by performing both experiment and calculation. It was clarified that the transient overall equivalent heat and mass transfer does not strongly depend on the air flow rate through the packed bed, the averaged equivalent mass transfer is governed by surface and pore diffusion in a particle of adsorbent at low flow rate. Moreover, the coefficient during the adsorption process is slightly larger than desorption. An equation of the overall mass transfer coefficient is derived. It shows five times as large as the value estimated by experiment. Therefore, the correlation and fitting parameters are presented for prediction of the overall heat and mass transfer coefficients. The estimation accuracy was improved.

  16. Moment equations for chromatography based on Langmuir type reaction kinetics.

    Science.gov (United States)

    Miyabe, Kanji

    2014-08-22

    Moment equations were derived for chromatography, in which the reaction kinetics between solute molecules and functional ligands on the stationary phase was represented by the Langmuir type rate equation. A set of basic equations of the general rate model of chromatography representing the mass balance, mass transfer rate, and reaction kinetics in the column were analytically solved in the Laplace domain. The moment equations for the first absolute moment and the second central moment in the real time domain were derived from the analytical solution in the Laplace domain. The moment equations were used for predicting the chromatographic behavior under hypothetical HPLC conditions. The influence of the parameters relating to the adsorption equilibrium and to the reaction kinetics on the chromatographic behavior was quantitatively evaluated. It is expected that the moment equations are effective for a detailed analysis of the influence of the mass transfer rates and of the Langmuir type reaction kinetics on the column efficiency.

  17. EMERGING TECHNOLOGY BULLETIN: SPOUTED BED REACTOR

    Science.gov (United States)

    The Spouted Bed Reactor (SBR) technology utilizes the unique attributes of the "spouting " fluidization regime, which can provide heat transfer rates comparable to traditional fluid beds, while providing robust circulation of highly heterogeneous solids, concurrent with very agg...

  18. [Historical analysis of the hospital bed].

    Science.gov (United States)

    Fajardo-Ortiz, Guillermo; Fajardo-Dolci, Germán

    2010-01-01

    Until now the bed has been the basic physical resource in hospitals. This type of furniture has served to study and treat patients, through out the centuries it has undergone changes in the materials they are made of dimensions, functionality, accessories, aesthetic, and design. The hospital bed history is not well known, there are thousands of documents about the evolution of hospitals, but not enough is known about hospital beds, a link between the past and the present. The medical, anthropological, technological, social, and economic dynamics and knowledge have produced a variety of beds in general and hospital beds in particular. From instinctive, rustic, poor and irregular "sites" that have differed in shape and size they had evolved into ergonomic equipment. The history of the hospital bed reflects the culture, techniques and human thinking. Current hospital beds include several types: for adults, for children, for labor, for intensive therapy, emergency purposes, census and non census beds etc.

  19. Chinese Bedding Technology Standard under Drafting

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    National Home Textile Standardization Technology Committee(NHTSTC)set up its Bedding Branch Committee. This will promote the work of Chinese bedding technology standardization and a symbol that China step up to meet the

  20. Adsorption recovery of thorium(IV) by Myrica rubra tannin and larch tannin immobilized onto collagen fibres

    International Nuclear Information System (INIS)

    Novel adsorbents which can concentrate Th(IV) in aqueous solution were prepared by immobilizing Myrica rubra tannin and larch tannin onto collagen fibre matrices. The adsorption capacities of the immobilized tannins to Th(IV) are related to temperature and pH value of the adsorption process. For example, when the initial concentration of Th(IV) was 116.0 mg x l-1 and the immobilized tannin was 100 mg, the adsorption capacities of immobilized Myrica rubra tannin and larch tannin were 55.98 mg Th(IV) x g-1 and 13.19 mg Th(IV) x g-1, respectively at 303 K, and 73.67 mg Th(IV) x g-1 and 18.19 mg Th(IV) x g-1 at 323 K. It was also found that the higher adsorption capacity was obtained at higher pH value. The adsorption equilibrium data of the immobilized tannins for Th(IV) can be well fitted by the Langmuir model and the mechanism of the adsorption was found to be a chemical adsorption. In general, the adsorption capacity of immobilized Myrica rubra tannin to Th(IV) is significantly higher than that of immobilized larch tannin, probably due to the fact that the B ring of Myrica rubra tannin has a pyrogallol structure which has higher reaction activity with metal ions. The breakthrough point of the adsorption column of immobilized Myrica rubra tannin was at 33 bed volumes for the experimental system. The mass transfer coefficient of adsorption column determined by Adams-Bohart equation was 1.61 x 10-4 l x mg-1 x min-1. The adsorption column can be easily regenerated by 0.1 mol x l-1 HNO3 solution, showing outstanding ability of concentrating Th(IV). (author)

  1. Adsorption of Antibiotics on Graphene and Biochar in Aqueous Solutions Induced by π-π Interactions

    Science.gov (United States)

    Peng, Bingquan; Chen, Liang; Que, Chenjing; Yang, Ke; Deng, Fei; Deng, Xiaoyong; Shi, Guosheng; Xu, Gang; Wu, Minghong

    2016-08-01

    The use of carbon based materials on the removal of antibiotics with high concentrations has been well studied, however the effect of this removal method is not clear on the actual concentration of environments, such as the hospital wastewater, sewage treatment plants and aquaculture wastewater. In this study, experimental studies on the adsorption of 7 antibiotics in environmental concentration of aqueous solutions by carbon based materials have been observed. Three kinds of carbon materials have shown very fast adsorption to antibiotics by liquid chromatography-tandem mass spectrometry (LC-MS-MS) detection, and the highest removal efficiency of antibiotics could reach to 100% within the range of detection limit. Surprisedly, the adsorption rate of graphene with small specific surface area was stronger than other two biochar, and adsorption rate of the two biochar which have approximate specific surface and different carbonization degree, was significantly different. The key point to the present observation were the π-π interactions between aromatic rings on adsorbed substance and carbon based materials by confocal laser scanning microscope observation. Moreover, adsorption energy markedly increased with increasing number of the π rings by using the density functional theory (DFT), showing the particular importance of π-π interactions in the adsorption process.

  2. Enhanced adsorption of humic acids on ordered mesoporous carbon compared with microporous activated carbon.

    Science.gov (United States)

    Liu, Fengling; Xu, Zhaoyi; Wan, Haiqin; Wan, Yuqiu; Zheng, Shourong; Zhu, Dongqiang

    2011-04-01

    Humic acids are ubiquitous in surface and underground waters and may pose potential risk to human health when present in drinking water sources. In this study, ordered mesoporous carbon was synthesized by means of a hard template method and further characterized by X-ray diffraction, N2 adsorption, transition electron microscopy, elemental analysis, and zeta-potential measurement. Batch experiments were conducted to evaluate adsorption of two humic acids from coal and soil, respectively, on the synthesized carbon. For comparison, a commercial microporous activated carbon and nonporous graphite were included as additional adsorbents; moreover, phenol was adopted as a small probe adsorbate. Pore size distribution characterization showed that the synthesized carbon had ordered mesoporous structure, whereas the activated carbon was composed mainly of micropores with a much broader pore size distribution. Accordingly, adsorption of the two humic acids was substantially lower on the activated carbon than on the synthesized carbon, because of the size-exclusion effect. In contrast, the synthesized carbon and activated carbon showed comparable adsorption for phenol when the size-exclusion effect was not in operation. Additionally, we verified by size-exclusion chromatography studies that the synthesized carbon exhibited greater adsorption for the large humic acid fraction than the activated carbon. The pH dependence of adsorption on the three carbonaceous adsorbents was also compared between the two test humic acids. The findings highlight the potential of using ordered mesoporous carbon as a superior adsorbent for the removal of humic acids.

  3. Adsorption kinetics of pesticide in soil assessed by optofluidics-based biosensing platform.

    Science.gov (United States)

    Long, Feng; Zhu, Anna; Shi, Hanchang; Sheng, Jianwu; Zhao, Zhen

    2015-02-01

    The adsorption of pesticides in soil is a key process that affects transport, degradation, mobility, and bioaccumulation of these substances. To obtain extensive knowledge regarding the adsorption processes of pesticides in the environment, the new green assay technologies for the rapid, sensitive, field-deployable, and accurate quantification of pesticides are required. In the present study, an evanescent wave-based optofluidics biosensing platform (EWOB) was developed by combining advanced photonics and microfluidics technology for the rapid sensitive immunodetection and adsorption kinetics assay of pesticides. The robustness, reusability, and accuracy of the EWOB allow an enhanced prediction of pesticide adsorption kinetics in soil. Using atrazine (ATZ) as the target model, we found that the adsorption kinetics in soil followed a pseudo-second-order kinetic model. EWOB was compared with liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method and yielded a good correlation coefficient (r(2)=0.9968). The underestimated results of LC-MS/MS resulted in a higher adsorption constant of ATZ in soil derived from LC-MS/MS than that of a biosensor. The proposed EWOB system provides a simple, green, and powerful tool to investigate the transport mechanism and fate of pesticide residues.

  4. Polyglycidyl methacrylate based immunoaffinity cryogels for insulin adsorption

    International Nuclear Information System (INIS)

    Immunoaffinity chromatography (IAC) is a kind of bioaffinity chromatography which used antibodies or antibody-related molecules as the stationary phase. IAC is used by many applications for analytical, clinical and diagnostic purposes, particularly preferring in analytical purposes on one-step separation and purification of target compounds. Moreover, immunoaffinity chromatography is used in antibody enrichment and separation of cells. IAC columns are usually applied in the antibody experiments due to powerful and selective binding of antibodies and/or their target antigens. Antigen or antibody molecules could be immobilized to the solid support. Therefore, target antibody or cell is purified. Specific bioligands can be immobilized directly on glycidyl based polymeric material with simple acid–base catalyst. In this study, polyglycidyl methacrylate based therefore cryogels were prepared and anti-insulin antibodies were immobilized on porous surface of cryogels. Swelling test, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and scanning electron microscopy (SEM) were conducted to characterize cryogels developed. To optimize separation conditions, effects of pH, initial insulin concentration, flow rate, salt concentration, contact time and temperature on insulin adsorption capacity were examined. The results indicated that the immunoaffinity cryogel developed here could be classified as good alternative with prominent properties such as high reusability and cost-friendly adsorbent and would be one of the primary reports for immunoaffinity purification of insulin molecules in not only lab-scale but also for industrial purposes. - Highlights: • Polyglycidyl methacrylate based cryogels developed as stationary phase • Immunoaffinity cryogels for reusable and cost-friendly insulin adsorption • Increase in worldwide prevalence of diabetes, type 1 or 2 • An exponential increase in the demand on insulin market • Guiding researchers for not

  5. Polyglycidyl methacrylate based immunoaffinity cryogels for insulin adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Memmedova, Türkan; Armutcu, Canan; Uzun, Lokman, E-mail: lokman@hacettepe.edu.tr; Denizli, Adil

    2015-07-01

    Immunoaffinity chromatography (IAC) is a kind of bioaffinity chromatography which used antibodies or antibody-related molecules as the stationary phase. IAC is used by many applications for analytical, clinical and diagnostic purposes, particularly preferring in analytical purposes on one-step separation and purification of target compounds. Moreover, immunoaffinity chromatography is used in antibody enrichment and separation of cells. IAC columns are usually applied in the antibody experiments due to powerful and selective binding of antibodies and/or their target antigens. Antigen or antibody molecules could be immobilized to the solid support. Therefore, target antibody or cell is purified. Specific bioligands can be immobilized directly on glycidyl based polymeric material with simple acid–base catalyst. In this study, polyglycidyl methacrylate based therefore cryogels were prepared and anti-insulin antibodies were immobilized on porous surface of cryogels. Swelling test, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and scanning electron microscopy (SEM) were conducted to characterize cryogels developed. To optimize separation conditions, effects of pH, initial insulin concentration, flow rate, salt concentration, contact time and temperature on insulin adsorption capacity were examined. The results indicated that the immunoaffinity cryogel developed here could be classified as good alternative with prominent properties such as high reusability and cost-friendly adsorbent and would be one of the primary reports for immunoaffinity purification of insulin molecules in not only lab-scale but also for industrial purposes. - Highlights: • Polyglycidyl methacrylate based cryogels developed as stationary phase • Immunoaffinity cryogels for reusable and cost-friendly insulin adsorption • Increase in worldwide prevalence of diabetes, type 1 or 2 • An exponential increase in the demand on insulin market • Guiding researchers for not

  6. Fluidized Bed Reactor as Solid State Fermenter

    OpenAIRE

    Krishnaiah, K.; Janaun, J.; Prabhakar, A.

    2005-01-01

    Various reactors such as tray, packed bed, rotating drum can be used for solid-state fermentation. In this paper the possibility of fluidized bed reactor as solid-state fermenter is considered. The design parameters, which affect the performances are identified and discussed. This information, in general can be used in the design and the development of an efficient fluidized bed solid-state fermenter. However, the objective here is to develop fluidized bed solid-state fermenter for palm kerne...

  7. Study of Solar Driven Silica gel-Water based Adsorption Chiller

    Science.gov (United States)

    Habib, K.; Assadi, M. K.; Zainudin, M. H. B.

    2015-09-01

    In this study, a dynamic behaviour of a solar powered single stage four bed adsorption chiller has been analysed designed for Malaysian climate. Silica gel and water have been used as adsorbent-refrigerant pair. A simulation program has been developed for modeling and performance evaluation of the chiller using the meteorological data of Kuala Lumpur. The optimum cooling capacity and coefficient of performance (COP) are calculated in terms of adsorption/desorption cycle time and regeneration temperature. Results indicate that the chiller is feasible even when low temperature heat source is available. Results also show that the adsorption cycle can achieve a cooling capacity of 14 kW when the heat source temperature is about 85°C.

  8. Study on structural characteristics and adsorption performance of ultrasonic treated Mn-containing sulfur transfer agent

    Institute of Scientific and Technical Information of China (English)

    Ruiyu Jiang; Jiling Zhang; Lei Zhang; Qinfang Zhang; Guihua Hou; Ning Xu

    2014-01-01

    To prepare manganese-containing spinel sulfur transfer agent with acid peptization, ultrasonic wave is used for the first time to modify the structure of sulfur transfer agent in this work. Mini fixed bed reactor was used to investigate the effect of ultrasonic power, time and temperature on the structure and oxidation adsorption performance of sulfur transfer agent and the adsorption kinetics and mechanism of SO2 were analyzed. SEM, TEM, XRD and N2 adsorption-desorption techniques were employed to characterize and analyse the function of sulfur transfer agent. The results indicated that manganese-containing spinel is a kind of promising sulfur transfer agent and exhibits higher sulfur capacity and desulfurization degree under the selected conditions of the ultrasonic wave power of 60%, and with the treatment period for 3 h at a temperature of 60◦C.

  9. A chromatographic study of carbon monoxide adsorption on a clinoptilolite-containing natural zeolitic material

    OpenAIRE

    Narin, Güler; Yılmaz, Selahattin; Ülkü, Semra

    2004-01-01

    In this study, the equilibrium and kinetic parameters for CO adsorption on clinoptilolite-rich natural zeolitic material were determined by the concentration pulse chromatography technique. Experiments were carried out at different column temperatures (60-120°C) and interstitial carrier gas velocities (3.1-16.3 cm/s) using a clinoptilolite-rich natural zeolitic material packed column. The equilibrium and kinetic parameters were determined by matching the moments of the experimentally obtained...

  10. A biological oil adsorption filter

    Energy Technology Data Exchange (ETDEWEB)

    Pasila, A. [University of Helsinki (Finland). Dept. of Agricultural Engineering and Household Technology

    2005-12-01

    A new oil adsorption method called adsorption filtration (AF) has been developed. It is a technology where by oil residues can be cleaned from water by running it through a simple filter made from freeze treated, dried, milled and then fragmented plant material. By choosing suitable plants and fragmentation sizes it is possible to produce filters, which pass water but adsorb oil. The aim of this study was to investigate the possibilities of manufacturing oil adsorbing filter materials from reed canary grass (Phalaris arundinacea), flax (Linum usitatissimum L.) or hemp fibre (Cannabis sativa L.). The oil (80 ml) was mixed with de-ionised water (200 ml) and this mixture was filtered through 10 or 20 g adsorption filters. Fine spring harvested hemp fibre (diameter less than 1 mm) and reed canary grass fragments adsorb 2-4 g of oil per gram of adsorption material compared to 1-3 g of water. Adsorption filtration is thus a novel way of gathering spilled oil in shallow coastal waters before the oil reaches the shore. (author)

  11. Comparative study of carbon nanotubes and granular activated carbon: Physicochemical properties and adsorption capacities.

    Science.gov (United States)

    Gangupomu, Roja Haritha; Sattler, Melanie L; Ramirez, David

    2016-01-25

    The overall goal was to determine an optimum pre-treatment condition for carbon nanotubes (CNTs) to facilitate air pollutant adsorption. Various combinations of heat and chemical pre-treatment were explored, and toluene was tested as an example hazardous air pollutant adsorbate. Specific objectives were (1) to characterize raw and pre-treated single-wall (SW) and multi-wall (MW) CNTs and compare their physical/chemical properties to commercially available granular activated carbon (GAC), (2) to determine the adsorption capacities for toluene onto pre-treated CNTs vs. GAC. CNTs were purified via heat-treatment at 400 °C in steam, followed by nitric acid treatment (3N, 5N, 11N, 16N) for 3-12 h to create openings to facilitate adsorption onto interior CNT sites. For SWNT, Raman spectroscopy showed that acid treatment removed impurities up to a point, but amorphous carbon reformed with 10h-6N acid treatment. Surface area of SWNTs with 3 h-3N acid treatment (1347 m(2)/g) was higher than the raw sample (1136 m(2)/g), and their toluene maximum adsorption capacity was comparable to GAC. When bed effluent reached 10% of inlet concentration (breakthrough indicating time for bed cleaning), SWNTs had adsorbed 240 mg/g of toluene, compared to 150 mg/g for GAC. Physical/chemical analyses showed no substantial difference for pre-treated vs. raw MWNTs. PMID:26476807

  12. Removal of cyanobacteria toxins from drinking water by adsorption on activated carbon fibers

    Directory of Open Access Journals (Sweden)

    Eden Cavalcanti de Albuquerque Júnior

    2008-09-01

    Full Text Available Natural fibers from macadamia nut shell, dried coconut shell endocarp, unripe coconut mesocarp, sugarcane bagasse and pine wood residue were used to prepare activated carbon fibers (ACF with potential application for removing microcystins. The ACF from pine wood and sugar cane bagasse were used to remove [D-Leucine¹]MCYST-LR from water. After 10 minutes of contact time, more than 98% of toxin was removed by the ACF. The microcystin adsorption monolayer, q m, in the ACF recovered 200 and 161 µg.mg-1, with the Langmuir adsorption constant, K L, of 2.33 and 1.23 L.mg-1. Adsorption of [D-Leucine¹]MCYST-LR in continuous process was studied for a fixed-bed ACF prepared from coconut shell and sugar cane bagasse and for two commercial activated carbon samples from treatment water plants of two Brazilian hemodialysis centers. Saturation of the beds occurred after 80 to 320 minutes, and the adsorption capacity for that toxin varied from 4.11 to 12.82 µg.mg-1.

  13. Groundwater Arsenic Adsorption on Granular TiO2: Integrating Atomic Structure, Filtration, and Health Impact.

    Science.gov (United States)

    Hu, Shan; Shi, Qiantao; Jing, Chuanyong

    2015-08-18

    A pressing challenge in arsenic (As) adsorptive filtration is to decipher how the As atomic surface structure obtained in the laboratory can be used to accurately predict the field filtration cycle. The motivation of this study was therefore to integrate molecular level As adsorption mechanisms and capacities to predict effluent As from granular TiO2 columns in the field as well as its health impacts. Approximately 2,955 bed volumes of groundwater with an average of 542 μg/L As were filtered before the effluent As concentration exceeded 10 μg/L, corresponding to an adsorption capacity of 1.53 mg As/g TiO2. After regeneration, the TiO2 column could treat 2,563 bed volumes of groundwater, resulting in an As load of 1.36 mg/g TiO2. Column filtration and EXAFS results showed that among coexisting ions present in groundwater, only Ca(2+), Si(OH)4, and HCO3(-) would interfere with As adsorption. The compound effects of coexisting ions and molecular level structural information were incorporated in the PHREEQC program to satisfactorily predict the As breakthrough curves. The total urinary As concentration from four volunteers of local residences, ranging from 972 to 2,080 μg/L before groundwater treatment, decreased to the range 31.7-73.3 μg/L at the end of the experimental cycle (15-33 days). PMID:26198737

  14. 海藻酸镧颗粒除氟研究:吸附剂物性和吸附机理%Fluoride Removal by Lanthanum Alginate Bead:Adsorbent Characterization and Adsorption Mechanism

    Institute of Scientific and Technical Information of China (English)

    霍亚坤; 丁文明; 黄霞; 徐静年; 赵梦华

    2011-01-01

    Lanthanum alginate bead is a new, highly active adsorbent. In the present study, we investigated its adsorption performance and its adsorption mechanism. The adsorption isotherm for fluoride onto lanthanum alginate bead fits the Langmuir model well, and the maximum adsorption capacity is 197.2 mg·g-1. X-ray diffraction shows the amorphous nature of lanthanum alginate bead, which allows for better accessibility to fluoride and thus better activity. Infrared spectra of lanthanum alginate bead before and after adsorption confirm its stable skeletal structure.Scanning electron microscopy shows that the dense surface structure of the adsorbent appear cracks after adsorption.The adsorption mechanism of lanthanum alginate bead is considered as an ion exchange between F- and Cl- or OH-,as verified from the adsorbent and the solution by pH effect, energy dispersive X-ray, and ion chromatography.

  15. Bed Bug Education for School Maintenance

    Science.gov (United States)

    Henriksen, Missy

    2012-01-01

    Bed bugs are a growing problem, not only in homes and hotels, but also in schools and colleges. Facility administrators and staff need to understand the bed bug resurgence and develop best practices to deal with an infestation. In this article, the author offers tips for preventing and treating bed bugs in school and university settings.

  16. 21 CFR 868.5180 - Rocking bed.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rocking bed. 868.5180 Section 868.5180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5180 Rocking bed. (a) Identification. A rocking bed is a...

  17. Analytical Modeling of CO2 Storage and Enhanced Coal Bed Methane Recovery

    Science.gov (United States)

    Seto, C. J.; Jessen, K.; Orr, F. M.

    2005-12-01

    Injection of CO2 into deep unminable coal seams is an option for geological storage of CO2. In these systems, adsorption of gas on the internal surfaces of the coal is the storage mechanism. In many of these reservoirs, large amounts of CH4 are adsorbed onto the coal. CO2 is preferentially adsorbed compared to CH4, which offers the possibility of desorption and increased recovery of CH4 from coal without lowering pressure in the coal bed. The interaction between CO2 sequestration and enhanced CH4 production makes coal reservoirs interesting candidates for sequestration. We report analytical solutions for one-dimensional, two-phase, three-component flow with adsorption of gas components onto coal surfaces in the absence of dispersion in the flowing phases. The solutions were obtained by the method of characteristics. We present solutions for combined flow of brine, CO2, and CH4, with solubility of both gas components in the brine and with adsorption represented by constant equilibrium partition coefficients. The solutions consist of shocks and continuous variations. We show that the arrangements of shocks and rarefactions depends on the relative strength of the adsorption of the gas components. These solutions provide insight into the complex interplay of adsorption, phase behavior and convection in these systems. Improved understanding of the physics of these displacements will aid in developing more efficient and physically accurate techniques for predicting the movement and fate of injected CO2 in the subsurface.

  18. A Continuous Procedure Based on Column Chromatography to Purify Anthocyanins from Schisandra chinensis by a Macroporous Resin plus Gel Filtration Chromatography

    Directory of Open Access Journals (Sweden)

    Daran Yue

    2016-02-01

    Full Text Available In our previous study, as natural food colorants and antioxidants, the color and content stabilities of Schisandra chinensis (S. chinensis anthocyanins were investigated. In this work, the purification process parameters of S. chinensis anthocyanins using a macroporous resin and gel filtration chromatography were evaluated. The optimized parameters of static adsorption and desorption were as follows. The selected resin is HPD-300 (nonpolar copolymer styrene type resin, and the anthocyanins adsorption saturation capacity of HPD-300 resin was 0.475 mg/g dry resin. Adsorption time was 4 h, and 0.517 mg/mL of S. chinensis anthocyanins was adsorbed on the resin column with a flow rate of 39 mL/h (3 BV/h. After adsorption, the anthocyanins were completely desorpted with 2.5 BV of 90% (v/v ethanol solution, and the desorption flow rate was 13 mL/h (1 BV/h. After purification by dynamic adsorption and desorption, the anthocyanins content in the effluent increased from 47.6 mg/g to 128.4 mg/g, the purity of anthocyanins increased six-fold from 5.08% to 30.43%, and the anthocyanins recovery was 96.5%. The major constituent of S. chinensis anthocyanins was isolated with Bio-Gel P2 gel filtration chromatography, and it was detected by liquid chromatography electrospray ionisation tandem mass spectrometry (LC-ESI-MS as cyanidin-3-O-xylosylrutinoside. Moreover, the antioxidant activities of S. chinensis anthocyanins were investigated. After purification using the HPD-300 resin, the antioxidant activities of anthocyanins were increased 1.2-fold (FRAP and 1.7-fold (ABTS.

  19. A Continuous Procedure Based on Column Chromatography to Purify Anthocyanins from Schisandra chinensis by a Macroporous Resin plus Gel Filtration Chromatography.

    Science.gov (United States)

    Yue, Daran; Yang, Lei; Liu, Shouxin; Li, Jian; Li, Wei; Ma, Chunhui

    2016-02-06

    In our previous study, as natural food colorants and antioxidants, the color and content stabilities of Schisandra chinensis (S. chinensis) anthocyanins were investigated. In this work, the purification process parameters of S. chinensis anthocyanins using a macroporous resin and gel filtration chromatography were evaluated. The optimized parameters of static adsorption and desorption were as follows. The selected resin is HPD-300 (nonpolar copolymer styrene type resin), and the anthocyanins adsorption saturation capacity of HPD-300 resin was 0.475 mg/g dry resin. Adsorption time was 4 h, and 0.517 mg/mL of S. chinensis anthocyanins was adsorbed on the resin column with a flow rate of 39 mL/h (3 BV/h). After adsorption, the anthocyanins were completely desorpted with 2.5 BV of 90% (v/v) ethanol solution, and the desorption flow rate was 13 mL/h (1 BV/h). After purification by dynamic adsorption and desorption, the anthocyanins content in the effluent increased from 47.6 mg/g to 128.4 mg/g, the purity of anthocyanins increased six-fold from 5.08% to 30.43%, and the anthocyanins recovery was 96.5%. The major constituent of S. chinensis anthocyanins was isolated with Bio-Gel P2 gel filtration chromatography, and it was detected by liquid chromatography electrospray ionisation tandem mass spectrometry (LC-ESI-MS) as cyanidin-3-O-xylosylrutinoside. Moreover, the antioxidant activities of S. chinensis anthocyanins were investigated. After purification using the HPD-300 resin, the antioxidant activities of anthocyanins were increased 1.2-fold (FRAP) and 1.7-fold (ABTS).

  20. Dynamic modeling of adsorption refrigerators for systm simulation; Dynamische Modellierung von Adsorptionskaelteanlagen fuer Systemsimulation

    Energy Technology Data Exchange (ETDEWEB)

    Dalibard, Antoine; Eicker, Ursula [Hochschule fuer Technik Stuttgart (Germany). Zentrum fuer nachhaltige Energietechnik; Ziegler, Felix [Technische Univ. Berlin (Germany). Inst. fuer Energietechnik, KT2

    2012-07-01

    The present paper deals with the dynamic modelling of two beds adsorption chillers with a special focus on the heat and mass recovery processes. A physical model able to calculate different heat recovery processes as well as mass recovery has been developed and implemented in the transient simulation environment TRNSYS. The main parameters required by the model and the modelling approach used are presented. Several concepts of heat recovery are presented and discussed. Also the concept of mass recovery is described. The model parameters have been adjusted to fit measurement data of an existing large capacity adsorption chiller (350 kW). This fitted model has been used to investigate the influence of the different heat recovery concepts on the chiller performance in steady state conditions. Depending on the concepts, the thermal COP can be increased by 10 to 30% in comparison with a cycle without heat recovery. Using mass recovery allows to increase the thermal COP by more than 10% and the cooling capacity by 2.5%. Combining both heat and mass recovery results in 35% COP improvement without reducing the cooling capacity. Comparing to other existing models, the model presents some advantages. It can simulate different heat recovery schemes and includes the possibility to calculate mass recovery between the two chambers. This model can be used for two beds adsorption chillers using different working pairs as silica-gel/water. Additionally, the model can be used for system simulation in order to investigate the influence of the transient behaviour of adsorption chillers on other components like cooling towers, solar collectors, buildings.. Further works will focus on the control optimization of adsorption chiller(s) at part load conditions. Also the primary energy savings potential of solar cooling systems equipped with adsorption chillers by using advanced controls will be investigated.

  1. Review of acute cancer beds.

    LENUS (Irish Health Repository)

    Evans, D S

    2012-01-01

    A review of admissions to cancer services at University Hospital Galway (UHG) was undertaken to assess the appropriateness of hospital usage. All cancer specialty patients admitted from 26-28 May 2009 were reviewed (n = 82). Chi square tests, Exact tests, and One-way ANOVA were utilised to analyse key issues emerging from the data. Fifty (61%) were classified as emergencies. Twenty three (67%) occupied a designated cancer bed with 24 (30%) in outlying non-oncology wards. The mean length of stay was 29.3 days. Possible alternatives to admission were identified for 15 (19%) patients. There was no evidence of discharge planning for 50 (60%) admissions. There is considerable potential to make more appropriate utilisation of UHG for cancer patients, particularly in terms of reducing bed days and length of stay and the proportion of emergency cancer admissions, and further developing integrated systems of discharge planning.

  2. Uranium removal from drinking water by adsorption onto granular ferric hydroxide (GEH); Entfernung von Uran aus Trinkwasser durch Adsorption an Granuliertem Eisenhydroxid (GEH)

    Energy Technology Data Exchange (ETDEWEB)

    Bahr, Carsten

    2012-07-01

    Uranium contamination of groundwater is encountered in many regions worldwide. Effective and simple removal technologies are required by waterworks faced with this problem, particularly in Germany which set a specification for maximum permissible uranium content in drinking water in November 2011. The present thesis examines the suitability of Granular Ferric Hydroxide (GEH) as a water treatment adsorbent for uranium removal. Adsorption isotherms generated in the studies showed that GEH is capable of adsorbing uranium, in fact achieving highest loading levels as compared to other oxide-based absorbents. Experimental data for uranium adsorption as a function of pH for the model systems U(VI) / H{sub 2}O and U(VI) / H{sub 2}O / CO{sub 2} successfully fits the Surface Complexation Model using the adjusted parameter set for ferrihydrite. Test findings showed that adsorption capacity varies substantially depending on the water matrix processed and is significantly reduced when real ground water or drinking water is processed. The main parameters influencing adsorption capacity were found to be pH and the associated carbonate concentration, as well as the concentrations of calcium and phosphate and to a lesser extent of sulfate and humic substances. The reduced capacity is caused by adsorption competition and changes in chemical speciation of uranium brought about by the water matrix at hand. Both the kinetics and the dynamics of adsorption can be successfully described by the Homogeneous Surface Diffusion Model (HSDM). The characteristic transport coefficients for film diffusion and particle diffusion were determined using empirical correlations and lab testing. The comparatively slow kinetics of adsorption are caused by the rate-determining particle diffusion and lead to a relatively flat breakthrough curve. Experiments on small adsorber columns (RSSCT method) were used to simulate uranium breakthrough in GEH fixed-bed filters on a laboratory scale, permitting accurate

  3. Assessment of CO₂ adsorption capacity on activated carbons by a combination of batch and dynamic tests.

    Science.gov (United States)

    Balsamo, Marco; Silvestre-Albero, Ana; Silvestre-Albero, Joaquín; Erto, Alessandro; Rodríguez-Reinoso, Francisco; Lancia, Amedeo

    2014-05-27

    In this work, batch and dynamic adsorption tests are coupled for an accurate evaluation of CO2 adsorption performance of three different activated carbons (AC) obtained from olive stones by chemical activation followed by physical activation with CO2 at varying times (i.e., 20, 40, and 60 h). Kinetic and thermodynamic CO2 adsorption tests from simulated flue gas at different temperatures and CO2 pressures are carried out under both batch (a manometric equipment operating with pure CO2) and dynamic (a lab-scale fixed-bed column operating with a CO2/N2 mixture) conditions. The textural characterization of the AC samples shows a direct dependence of both micropore and ultramicropore volume on the activation time; hence, AC60 has the higher contribution. The adsorption tests conducted at 273 and 293 K showed that when CO2 pressure is lower than 0.3 bar, the lower the activation time, the higher CO2 adsorption capacity; a ranking of ω(eq)(AC20) > ω(eq)(AC40) > ω(eq)(AC60) can be exactly defined when T = 293 K. This result is likely ascribed to the narrower pore size distribution of the AC20 sample, whose smaller pores are more effective for CO2 capture at higher temperature and lower CO2 pressure, the latter representing operating conditions of major interest for decarbonation of flue gas effluent. Moreover, the experimental results obtained from dynamic tests confirm the results derived from the batch tests in terms of CO2 adsorption capacity. It is important to highlight the fact that the adsorption of N2 on the synthesized AC samples can be considered to be negligible. Finally, the importance of proper analysis for data characterization and adsorption experimental results is highlighted for the correct assessment of the CO2 removal performance of activated carbons at different CO2 pressures and operating temperatures. PMID:24784997

  4. Mesoporous carbon adsorbents from melamine-formaldehyde resin using nanocasting technique for CO2 adsorption.

    Science.gov (United States)

    Goel, Chitrakshi; Bhunia, Haripada; Bajpai, Pramod K

    2015-06-01

    Mesoporous carbon adsorbents, having high nitrogen content, were synthesized via nanocasting technique with melamine-formaldehyde resin as precursor and mesoporous silica as template. A series of adsorbents were prepared by varying the carbonization temperature from 400 to 700°C. Adsorbents were characterized thoroughly by nitrogen sorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), elemental (CHN) analysis, Fourier transform infrared (FTIR) spectroscopy and Boehm titration. Carbonization temperature controlled the properties of the synthesized adsorbents ranging from surface area to their nitrogen content, which play major role in their application as adsorbents for CO2 capture. The nanostructure of these materials was confirmed by XRD and TEM. Their nitrogen content decreased with an increase in carbonization temperature while other properties like surface area, pore volume, thermal stability and surface basicity increased with the carbonization temperature. These materials were evaluated for CO2 adsorption by fixed-bed column adsorption experiments. Adsorbent synthesized at 700°C was found to have the highest surface area and surface basicity along with maximum CO2 adsorption capacity among the synthesized adsorbents. Breakthrough time and CO2 equilibrium adsorption capacity were investigated from the breakthrough curves and were found to decrease with increase in adsorption temperature. Adsorption process for carbon adsorbent-CO2 system was found to be reversible with stable adsorption capacity over four consecutive adsorption-desorption cycles. From three isotherm models used to analyze the equilibrium data, Temkin isotherm model presented a nearly perfect fit implying the heterogeneous adsorbent surface.

  5. Host receptors for bacteriophage adsorption.

    Science.gov (United States)

    Bertozzi Silva, Juliano; Storms, Zachary; Sauvageau, Dominic

    2016-02-01

    The adsorption of bacteriophages (phages) onto host cells is, in all but a few rare cases, a sine qua non condition for the onset of the infection process. Understanding the mechanisms involved and the factors affecting it is, thus, crucial for the investigation of host-phage interactions. This review provides a survey of the phage host receptors involved in recognition and adsorption and their interactions during attachment. Comprehension of the whole infection process, starting with the adsorption step, can enable and accelerate our understanding of phage ecology and the development of phage-based technologies. To assist in this effort, we have established an open-access resource--the Phage Receptor Database (PhReD)--to serve as a repository for information on known and newly identified phage receptors. PMID:26755501

  6. Bed bathing patients in hospital

    OpenAIRE

    L Downey; Lloyd, Hilary

    2008-01-01

    There are a number of circumstances that may affect an individual's ability to maintain personal hygiene. Hospitalised patients, and in particular those who are bedridden, may become dependent on nursing staff to carry out their hygiene needs. Assisting patients to maintain personal hygiene is a fundamental aspect of nursing care. However, it is a task often delegated to junior or newly qualified staff. This article focuses on the principles of bed bathing patients in hospital, correct proced...

  7. THE BAUXITES AND JELAR - BEDS

    Directory of Open Access Journals (Sweden)

    Krešimir Sakač

    1993-12-01

    Full Text Available Minor bauxite deposits and occurrences were formed in technically disturbed environments in the middle part of the Adriatic geotectonic unit in Dinarides, contemporary with the clastic Jelar-beds in the Late Lutetian time. Uneven chemical composition of these Eocene bauxites, their sporadic occurrences in developed paleorelief as well as characteristic petrographic composition of the immediate overlying rocks point out at different genetical conditions (the paper is published in Croatian.

  8. Solids mixing in spouted beds

    OpenAIRE

    Cook, H. H.; Bridgwater, J.; Professor J. Bridgwater

    1981-01-01

    Many industrial processes require contact between particles and a fluid or spray in order to effect drying, coating or granulation. One device capable of contacting fluid and particles efficiently is a spouted bed in which a jet of fluid is injected into solid particles. This forms an open channel or spout and induces material circulation in a downward moving annulus. For the continuous throughput of solids, knowledge is required of the mixing and particle motions within th...

  9. SPECIATION OF SELENIUM(IV) AND SELENIUM(VI) USING COUPLED ION CHROMATOGRAPHY: HYDRIDE GENERATION ATOMIC ABSORPTION SPECTROMETRY

    Science.gov (United States)

    A simple method was developed to speciate inorganic selenium in the microgram per liter range using coupled ion chromatography-hydride generation atomic absorption spectrometry. Because of the differences in toxicity and adsorption behavior, determination of the redox states selenite, Se(IV), and s...

  10. The statistical character of packed-bed heat transport properties

    OpenAIRE

    Wijngaarden, R.J.; Westerterp, K. R.

    1992-01-01

    Packed beds are essentially heterogeneous on a pellet scale. For random packed beds this heterogeneity causes a statistical character both on a pellet and bed scale. We discuss experimental results which deal with bed-scale statistics.

  11. Monomer Adsorption-Desorption Processes

    Institute of Scientific and Technical Information of China (English)

    KE Jian-Hong; LIN Zhen-Quan; CHEN Xiao-Shuang

    2009-01-01

    We propose an adsorption-desorption model for a deposit growth system, in which the adsorption and desorption of particles coexist. By means of the generalized rate equation we investigate the cluster (island) size distribution in the dynamic equilibrium state. The results show that the evolution behaviour of the system depends crucially on the details of the rate kernels. The cluster size distribution can take the ecale-frse power-law form in some cases, while it grows exponentially with size in other cases.

  12. Theoretical insight of adsorption cooling

    KAUST Repository

    Chakraborty, Anutosh

    2011-06-03

    This letter proposes and presents a thermodynamic formulation to calculate the energetic performances of an adsorption cooler as a function of pore widths and volumes of solid adsorbents. The simulated results in terms of the coefficient of performance are validated with experimental data. It is found from the present analysis that the performance of an adsorption cooling device is influenced mainly by the physical characteristics of solid adsorbents, and the characteristics energy between the adsorbent-adsorbate systems. The present study confirms that there exists a special type of silicagel having optimal physical characteristics that allows us to obtain the best performance.

  13. Method and apparatus for a combination moving bed thermal treatment reactor and moving bed filter

    Energy Technology Data Exchange (ETDEWEB)

    Badger, Phillip C.; Dunn, Jr., Kenneth J.

    2015-09-01

    A moving bed gasification/thermal treatment reactor includes a geometry in which moving bed reactor particles serve as both a moving bed filter and a heat carrier to provide thermal energy for thermal treatment reactions, such that the moving bed filter and the heat carrier are one and the same to remove solid particulates or droplets generated by thermal treatment processes or injected into the moving bed filter from other sources.

  14. Determination of Anions in Landifll Leachate Water by Activated Carbon Adsorption-Solid Phase Extraction-Ion Chromatography%活性炭吸附-固相萃取-离子色谱法快速测定垃圾渗滤液中的阴离子

    Institute of Scientific and Technical Information of China (English)

    黄朝颜; 孟洁; 吴艳芬

    2014-01-01

    建立了活性炭吸附–固相萃取–离子色谱法快速测定垃圾渗滤液中F–,Cl-,NO3–,PO43–,SO42–5种阴离子的方法。100 mL样品先经10 g预先洗涤烘干的活性炭吸附,然后通过吸附特性不同的ENVI–18(C18小柱)、PSA固相萃取小柱。利用C18小柱对水中有机污染物的萃取及键合相有双齿配体的PSA小柱对金属离子的螯合,除去渗滤液中大量的有机物和重金属,再经离子色谱检测。5种离子的质量浓度在1~10 mg/L范围内与其色谱峰面积呈良好的线性关系,线性相关系数大于0.999,F–,Cl-,NO3–,PO43–,SO42–的检出限分别为0.02,0.02,0.08,0.15,0.09 mg/L。5种离子的平均加标回收率为96%~105%,测定结果的相对标准偏差小于6%(n=6)。该方法简便快捷,测定结果准确可靠,可用于垃圾渗滤液中F–,Cl-,NO3–,PO43–,SO42–5种阴离子的测定。%A method based on activated carbon adsorption–solid phase extraction–ion chromatography for the determination of anions (F–,Cl–,NO3–,PO43–,SO42–) in landfill leachate water was developed. 100 mL landfill leachate water was enriched by 10 g activated carbon, two different kinds of solid phase extraction column: ENVI–18 and PSA. After the pretreatment,much of the organic matter and high heavy metal content have been removed. Then the sample was analyzed by ion chromatography. The concentration offive aions had good linear relationship with the chromatography peak area in the range of 1–10 mg/L. The recoveries were 96%–105%,with coefficients of variation below 5%(n=6). The method is simple,reliable and suitable for determining anions in landfill leachate water.

  15. The effect of food and ice cream on the adsorption capacity of paracetamol to high surface activated charcoal

    DEFF Research Database (Denmark)

    Høgberg, Lotte Christine Groth; Angelo, Helle Riis; Christophersen, Anne Bolette;

    2003-01-01

    The effect of added food mixture (as if food was present in the stomach of an intoxicated patient) or 4 different types of ice cream (added as a flavouring and lubricating agent) on the adsorption of paracetamol (acetaminophen) to 2 formulations of activated charcoal was determined in vitro......, and paracetamol were mixed with either food mixture or ice cream followed by one hr incubation. The maximum adsorption capacity of paracetamol to activated charcoal was calculated using Langmuirs adsorption isotherm. Paracetamol concentration was analyzed using high pressure liquid chromatography. In the presence...... of food, the paracetamol adsorption capacity of the 2 activated charcoals was reduced by max. 19% (Pfood (Hoegberg et al. 2002). Depending on which type of ice cream was mixed with the charcoal...

  16. The application of normal logging methods in coal bed gas explanation%常规测井方法在煤层气解释中的应用

    Institute of Scientific and Technical Information of China (English)

    宋世杰

    2015-01-01

    煤层气是煤岩在成煤和演化过程中生成的以甲烷为主,现今仍以游离、吸附、固容状态存于煤层中的一部分气体。常规测井方法能有效识别煤层,计算出的煤层气含量为评估煤层气藏储量提供科学依据。%Coal bed gas mainly consists of methane during its formation and evolution. Nowadays, it exists in coal bed as the station of free state, adsorption, solid solution. Normal logging methods could identify coal bed and calculate the quantity of the coal bed gas,which provide scientific reference for assessment of the reserves of the coal bed gas.

  17. Equilibrium bed-concentration of nonuniform sediment

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Knowledge of the equilibrium bed-concentration is vital to mathematical modeling of the river-bed deformation associated with suspended load but previous investigations only dealt with the reference concentration of uniform sediment because of difficulties in observation of the bed-concentration. This work is a first attempt to develop a theoretical formula for the equilibrium bed-concentration of any fraction of nonuniform sediment defined at the bed-surface. The formula is based on a stochastic-mechanistic model for the exchange of nonuniform sediment near the bed, and described as a function of incipient motion probability, non-ceasing probability, pick-up probability, and the ratio of the average single-step continuous motion time to static time. Comparison of bed-concentration calculated from the proposed formula with the measured data showed satisfactory agreement, indicating the present formula can be used for solving the differential equation governing the motion of suspended load.

  18. Bed bug aggregation pheromone finally identified.

    Science.gov (United States)

    Gries, Regine; Britton, Robert; Holmes, Michael; Zhai, Huimin; Draper, Jason; Gries, Gerhard

    2015-01-19

    Bed bugs have become a global epidemic and current detection tools are poorly suited for routine surveillance. Despite intense research on bed bug aggregation behavior and the aggregation pheromone, which could be used as a chemical lure, the complete composition of this pheromone has thus far proven elusive. Here, we report that the bed bug aggregation pheromone comprises five volatile components (dimethyl disulfide, dimethyl trisulfide, (E)-2-hexenal, (E)-2-octenal, 2-hexanone), which attract bed bugs to safe shelters, and one less-volatile component (histamine), which causes their arrestment upon contact. In infested premises, a blend of all six components is highly effective at luring bed bugs into traps. The trapping of juvenile and adult bed bugs, with or without recent blood meals, provides strong evidence that this unique pheromone bait could become an effective and inexpensive tool for bed bug detection and potentially their control. PMID:25529634

  19. A FIXED BED SORPTION SYSTEM FOR DEFLUORIDATION OF GROUND WATER

    Directory of Open Access Journals (Sweden)

    Ayoob Sulaiman

    2009-06-01

    Full Text Available The presence of excess fluoride in ground water has become a global threat with as many as 200 million people affected in more than 35 countries in all the continents. Of late, there have been significant advances in the knowledge base regarding the effects of excess fluoride on human health. As a result, defluoridation of ground water is regarded as one of the key areas of attention among the universal water community triggering global research. This study describes the sorptive responses of a newly developed adsorbent, alumina cement granules (ALC, in its real-life application in fixed beds, for removing fluoride from the ground waters of a rural Indian village. ALC exhibited almost consistent scavenging capacity at various bed depths in column studies with an enhanced adsorption potential of 0.818 mg/g at a flow rate of 4 ml/min. The Thomas model was examined to describe the sorption process. The process design parameters of the column were obtained by linear regression of the model. In all the conditions examined, the Thomas model could consistently predict its characteristic parameters and describe the breakthrough sorption profiles in the whole range of sorption process.

  20. Cellulose hydrolysis by Trichoderma reesei cellulases: studies on adsorption, sugar production and synergism of cellobiohydrolase I,II and endoglucanase II

    Energy Technology Data Exchange (ETDEWEB)

    Medve, J.

    1997-02-01

    Three major cellulases have been purified by ion-exchange chromatography in an FPLC system. Microcrystalline cellulose (Avicel) was hydrolyzed by the single enzymes and by equimolar mixtures of CBH I-CBH II and CBH I-EG II. Enzyme adsorption was followed indirectly by selectively quantifying the enzymes in the supernatant by ion-exchange chromatography in an FPLC system. The (synergistic) production of small, soluble sugars (glucose, cellobiose and cellotriose) by the enzymes was followed by HPLC. 76 refs

  1. Waste Water Treatment-Bed of Coal Fly Ash for Dyes and Pigments Industry

    International Nuclear Information System (INIS)

    The highly porous power plant waste ashes have been utilized to treat toxic effluent of a dyes manufacturing plant. An attempt has been made for the first time in Pakistan, to generate an effective and economically sound treatment facility for the toxic effluent of a dyes manufacturing plant. This is an indigenous bed which could replace expensive treatment facilities, such as reverse osmosis (RO), granulated activated carbon (GAC) bed, etc. The treatment efficiency was improved by coupling coagulants with fly ash adsorbent bed. The ash was collected from coal fired boilers of power plant at Lakhra Power Generation Company, Jamshoro, Pakistan. The use of this ash resolved the disposal and environmental issues by treating wastewater of chemical, dyes and pigment industry. The treatment bed comprised of briquettes of coal fly ash coupled with commercial coagulant ferrous sulfate-lime reduced COD, color, turbidity and TSS of effluent remarkably. An adsorption capacity and chemical behavior of fly ash bed was also studied. In coagulation treatment, coagulant FeSO/sun 4/-lime influenced reduction of COD, color, turbidity and TSS by 32 percentage, 48 percentage, 50 percentage and 51 percentage, respectively. The CFAB coupled with coagulant, resulted an excessive removal of color, TSS, COD, and turbidity by 88 percentage, 92 percentage, 67 percentage and 89 percentage, respectively. (author)

  2. Waste Water Treatment-Bed of Coal Fly Ash for Dyes and Pigments Industry

    Directory of Open Access Journals (Sweden)

    Syed Farman Ali Shah

    2015-12-01

    Full Text Available The highly porous power plant waste ashes have been utilized to treat toxic effluent of a dyes manufacturing plant. An attempt has been made for the first time in Pakistan, to generate an effective and economically sound treatment facility for the toxic effluent of a dyes manufacturing plant. This is an indigenous bed which could replace expensive treatment facilities, such as reverse osmosis (RO, granulated activated carbon (GAC bed, etc. The treatment efficiency was improved by coupling coagulants with fly ash adsorbent bed. The ash was collected from coal fired boilers of power plant at Lakhra Power Generation Company, Jamshoro, Pakistan. The use of this ash resolved the disposal and environmental issues by treating wastewater of chemical, dyes and pigment industry. The treatment bed comprised of briquettes of coal fly ash coupled with commercial coagulant ferrous sulfate-lime reduced COD, color, turbidity and TSS of effluent remarkably. An adsorption capacity and chemical behavior of fly ash bed was also studied. In coagulation treatment, coagulant FeSO4-lime influenced reduction of COD, color, turbidity and TSS by 32%, 48%, 50% and 51%, respectively. The CFAB coupled with coagulant, resulted an excessive removal of color, TSS, COD, and turbidity by 88%, 92%, 67% and89%, respectively.

  3. Use of rice husk for the removal of methylene blue in fixed-bed columns

    Directory of Open Access Journals (Sweden)

    Yurany A. Villada-Villada

    2014-08-01

    Full Text Available This work shows the use of rice husk in the removal of cationic dye methylene blue on continuous system. A factorial design 23 with center points and random distribution was implemented to evaluate the correlation of the experimental factors in the adsorption process. The considered variables were pH, particle size, salt presence, flow rate, dye initial concentration, and bed depth. The samples were analyzed in defined time intervals. The amount of removed dye was quantified by UV spectroscopy - Visible. Adams-Bohart, Thomas and BDST (Bed-depht/service time analysis models were used to predict the breakthrough curves using non-linear regression and establish the characteristic parameters of the process. It was found that the transference of dye toward the adsorbent is favored by a basic pH, a small particle size, low flow rate and dye concentration, and high bed depth. The design of experiments established that the initial dye concentration and the bed depth were the most significant factors. Regarding the models, the Thomas provided the best fit to describe the breakthrough curves in experimental conditions and Adams-Bohart was found suitable for dynamic behavior limited to the initial part. Finally, BDST model exhibited a good correlation and allowed to establish that bed depth is a determinant factor for scaling process.

  4. Investigation of Microgranular Adsorptive Filtration System

    Science.gov (United States)

    Cai, Zhenxiao

    Over the past few decades, enormous advances have been made in the application of low-pressure membrane filtration to both drinking water and wastewater treatment. Nevertheless, the full potential of this technology has not been reached, due primarily to limitations imposed by membrane fouling. In drinking water treatment, much of the fouling is caused by soluble and particulate natural organic matter (NOM). Efforts to overcome the problem have focused on removal of NOM from the feed solution, usually by addition of conventional coagulants like alum and ferric chloride (FeCl3) or adsorbents like powdered activated carbon (PAC). While coagulants and adsorbents can remove a portion of the NOM, their performance with respect to fouling control has been inconsistent, often reducing fouling but sometimes having no effect or even exacerbating fouling. This research investigated microgranular adsorptive filtration (muGAF), a process that combines three existing technologies---granular media filtration, packed bed adsorption, and membrane filtration---in a novel way to reduce membrane fouling while simultaneously removing NOM from water. In this technology, a thin layer of micron-sized adsorbent particles is deposited on the membrane prior to delivering the feed to the system. The research reported here represents the first systematic study of muGAF, and the results demonstrate the promising potential of this process. A new, aluminum-oxide-based adsorbent---heated aluminum oxide particles (HAOPs)---was synthesized and shown to be very effective for NOM removal as well as fouling reduction in muGAF systems. muGAF has also been demonstrated to work well with powdered activated carbon (PAC) as the adsorbent, but not as well as when HAOPs are used; the process has also been successful when used with several different membrane types and configurations. Experiments using a wide range of operational parameters and several analytical tools lead to the conclusion that the fouling

  5. Adsorption of Organics from Domestic Water Supplies.

    Science.gov (United States)

    McGuire, Michael J.; Suffet, Irwin H.

    1978-01-01

    This article discusses the current state of the art of organics removal by adsorption. Various theoretical explanations of the adsorption process are given, along with practical results from laboratory, pilot-scale, and full-scale applications. (CS)

  6. Flow Rates in Liquid Chromatography, Gas Chromatography and Supercritical Fluid Chromatography: A Tool for Optimization

    OpenAIRE

    Meurs, Joris

    2016-01-01

    This paper aimed to develop a standalone application for optimizing flow rates in liquid chromatography (LC), gas chromatography (GC) and supercritical fluid chromatography (SFC). To do so, Van Deemter’s equation, Knox’ equation and Golay’s equation were implemented in a MATLAB script and subsequently a graphical user interface (GUI) was created. The application will show the optimal flow rate or linear velocity and the corresponding plate height for the set input parameters. Furthermore, a p...

  7. ADSORPTION MALACHITE GREEN ON NATURAL ZEOLITE

    Directory of Open Access Journals (Sweden)

    Eko Ariyanto

    2012-02-01

    Full Text Available A natural zeolite was employed as adsorbent for reducing of malachite green from aqueous solution. A batch system was applied to study the adsorption of malachite green in single system on natural zeolite. The adsorption studies indicate that malachite green in single component system follows the second-order kinetics and the adsorption is diffusion process with two stages for malachite green. Malachite green adsorption isotherm follows the Langmuir model.

  8. Adsorption theory for polydisperse polymers.

    NARCIS (Netherlands)

    Roefs, S.P.F.M.; Scheutjens, J.M.H.M.; Leermakers, F.A.M.

    1994-01-01

    Most polymers are polydisperse. We extend the self-consistent field polymer adsorption theory due to Scheutjens and Fleer to account for an arbitrary polymer molecular weight distribution with a cutoff chain length Nmax. In this paper, the treatment is restricted to homopolymers. For this case a ver

  9. Adsorption of Levofloxacin to Goethite

    NARCIS (Netherlands)

    Qin, Xiaopeng; Liu, Fei; Zhao, Long; Hou, Hong; Wang, Guangcai; Li, Fasheng; Weng, Liping

    2016-01-01

    Batch experiments were conducted to investigate the adsorption of a widely used fluoroquinolone antibiotic levofloxacin (LEV) to goethite and effects of nitrate, sulfate, small organic acids, and humic acid (HA). The concentrations of LEV and small organic acids in single systems or mixtures were

  10. Scaling Laws of Polyelectrolyte Adsorption

    OpenAIRE

    Borukhov, I.; Andelman, D.; Orland, H.

    1997-01-01

    Adsorption of charged polymers (polyelectrolytes) from a semi-dilute solution to a charged surface is investigated theoretically. We obtain simple scaling laws for (i) the amount of polymer adsorbed to the surface, Gamma, and (ii) the width of the adsorbed layer D, as function of the fractional charge per monomer p and the salt concentration c_b. For strongly charged polyelectrolytes (p

  11. Simulation of the dynamic packing behavior of preparative chromatography columns via discrete particle modeling.

    Science.gov (United States)

    Dorn, Martin; Hekmat, Dariusch

    2016-03-01

    Preparative packed-bed chromatography using polymer-based, compressible, porous resins is a powerful method for purification of macromolecular bioproducts. During operation, a complex, hysteretic, thus, history-dependent packed bed behavior is often observed but theoretical understanding of the causes is limited. Therefore, a rigorous modeling approach of the chromatography column on the particle scale has been made which takes into account interparticle micromechanics and fluid-particle interactions for the first time. A three-dimensional deterministic model was created by applying Computational Fluid Dynamics (CFD) coupled with the Discrete Element Method (DEM). The column packing behavior during either flow or mechanical compression was investigated in-silico and in laboratory experiments. A pronounced axial compression-relaxation profile was identified that differed for both compression strategies. Void spaces were clearly visible in the packed bed after compression. It was assumed that the observed bed inhomogeneity was because of a force-chain network at the particle scale. The simulation satisfactorily reproduced the measured behavior regarding packing compression as well as pressure-flow dependency. Furthermore, the particle Young's modulus and particle-wall friction as well as interparticle friction were identified as crucial parameters affecting packing dynamics. It was concluded that compaction of the chromatographic bed is rather because of particle rearrangement than particle deformation. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 32:363-371, 2016. PMID:26588806

  12. Simulation of the dynamic packing behavior of preparative chromatography columns via discrete particle modeling.

    Science.gov (United States)

    Dorn, Martin; Hekmat, Dariusch

    2016-03-01

    Preparative packed-bed chromatography using polymer-based, compressible, porous resins is a powerful method for purification of macromolecular bioproducts. During operation, a complex, hysteretic, thus, history-dependent packed bed behavior is often observed but theoretical understanding of the causes is limited. Therefore, a rigorous modeling approach of the chromatography column on the particle scale has been made which takes into account interparticle micromechanics and fluid-particle interactions for the first time. A three-dimensional deterministic model was created by applying Computational Fluid Dynamics (CFD) coupled with the Discrete Element Method (DEM). The column packing behavior during either flow or mechanical compression was investigated in-silico and in laboratory experiments. A pronounced axial compression-relaxation profile was identified that differed for both compression strategies. Void spaces were clearly visible in the packed bed after compression. It was assumed that the observed bed inhomogeneity was because of a force-chain network at the particle scale. The simulation satisfactorily reproduced the measured behavior regarding packing compression as well as pressure-flow dependency. Furthermore, the particle Young's modulus and particle-wall friction as well as interparticle friction were identified as crucial parameters affecting packing dynamics. It was concluded that compaction of the chromatographic bed is rather because of particle rearrangement than particle deformation. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 32:363-371, 2016.

  13. Study on heat and mass transfer between a greenhouse considered as a solar air heater and a rock packed bed as ambient control system

    International Nuclear Information System (INIS)

    A general study on heat transfer in dry packed beds is made, with special emphasis in comparing different transient models and in identifying the required conditions by which the attained results are equivalent. The differences in thermal behaviour on packed beds, when simultaneous heat mass transfer occurs as wet air is used as heat transfer fluid and exchanges heat and water with the solid in the bed, is analyzed. We modelize wet packed beds considering them as one dimension adsorbents beds, with dispersive and non-dispersive models, where adsorption, condensation-evaporation and liquid water downward flow from condensate phenomena are present. Models were solved numerically and experiments with a rock bed with dry and wet air through it, were made to test assumptions and to further understand the behavior of the system, obtaining a pretty good agreement between expected and measured profiles of the temperature evolution within the packed bed. As a possible application of the wet rock bed for storage purposes, a forced ventilation greenhouse was characterized as a wet air solar heater and analyzed the energetic potential of storing the heat that has to be rejected during daytime to control the crop ambient conditions, in a rock bed for later use at night for heating. (author)

  14. An Undergraduate Column Chromatography Experiment.

    Science.gov (United States)

    Danot, M.; And Others

    1984-01-01

    Background information, list of materials needed, and procedures used are provided for an experiment designed to introduce undergraduate students to the theoretical and technical aspects of column chromatography. The experiment can also be shortened to serve as a demonstration of the column chromatography technique. (JN)

  15. The Berlin emissivity database (BED)

    Science.gov (United States)

    Maturilli, A.; Helbert, J.; Moroz, L.

    2008-03-01

    Remote-sensing infrared spectroscopy is the principal field of investigation for planetary surfaces composition. Past, present and future missions to the solar system bodies include in their payload, instruments measuring the emerging radiation in the infrared range. Apart from measuring the reflected radiance, more and more spacecrafts are equipped with instruments measuring directly the emitted radiation from the planetary surface. The emitted radiation is not only a function of the composition of the material but also of its texture and especially the grain size distribution. For the interpretation of the measured data an emissivity spectral library of planetary analogue materials in grain size fractions appropriate for planetary surfaces is needed. The Berlin emissivity database (BED) presented here is focused on relatively fine-grained size separates, providing thereby a realistic basis for the interpretation of thermal emission spectra of planetary regoliths. The BED is therefore complimentary to existing thermal emission libraries, like the ASU library for example. BED currently contains emissivity spectra of plagioclase and potassium feldspars, low Ca and high Ca pyroxenes, olivine, elemental sulfur, Martian analogue minerals and volcanic soils, and a lunar highland soil sample measured in the wavelength range from 7 to 22 μm as a function of particle size. For each sample we measured the spectra of four particle size separates ranging from <25 to 250 μm. The device we used is built at DLR (Berlin) and is coupled to a Fourier-transform infrared spectrometer Bruker IFS 88 purged with dry air and equipped with a nitrogen-cooled MCT detector. All spectra were acquired with a spectral resolution of 4 cm -1. We are currently working on upgrading our emissivity facility. A new spectrometer (Bruker VERTEX 80 V) and new detectors will allow us to measure the emissivity of samples in the wavelength range from 1 to 50 μm in a vacuum environment. This will be

  16. MICROTURBULENCE IN GRAVEL BED STREAMS

    Science.gov (United States)

    Papanicolaou, T.; Tsakiris, A. G.; Kramer, C. M.

    2009-12-01

    The overarching objective of this investigation was to evaluate the role of relative submergence on the formation and evolution of cluster microforms in gravel bed streams and its implications to bedload transport. Secondary objectives of this research included (1) a detailed analysis of mean flow measurements around a clast; and (2) a selected number of experimental runs where the mean flow characteristics are linked together with the bed micro-topography observations around a clast. It is hypothesized that the relative submergence is an important parameter in defining the feedback processes between the flow and clasts, which governs the flow patterns around the clasts, thus directly affecting the depositional patterns of the incoming sediments. To examine the validity of the hypothesis and meet the objectives of this research, 19 detailed experimental runs were conducted in a tilting, water recirculating laboratory flume under well-controlled conditions. A fixed array of clast-obstacles were placed atop a well-packed bed with uniform size glass beads. During the runs, multifractional spherical particles were fed upstream of the clast section at a predetermined rate. State-of-the-art techniques/instruments, such as imaging analysis software, Large Scale Particle Velocimeter (LSPIV) and an Acoustic Doppler Velocimetry (ADV) were employed to provide unique quantitative measurements for bedload fluxes, clast/clusters geomorphic patterns, and mean flow characteristics in the vicinity of the clusters. Different flow patterns were recorded for the high relative submergence (HRS) and low relative submergence (LRS) experimental runs. The ADV measurements provided improved insight about the governing flow mechanisms for the HRS runs. These mechanisms were described with flow upwelling at the center of the flume and downwelling occurring along the flume walls. Flow downwelling corresponded to an increase in the free surface velocity. Additionally, the visual observations

  17. [Special beds. Pulmonary therapy system].

    Science.gov (United States)

    Calixto Rodríguez, Joaquín; Rodríguez Martínez, Xavier; Marín i Vivó, Gemma; Paunellas Albert, Josep

    2008-10-01

    To be bedridden reduces one's capacity to move and produces muscular debility that affects the respiratory system leading to a decreased effectiveness in expectoration, the ability to spit up sputum. The pulmonary therapy system integrated in a bed is the result of applying motorized elements to the articulation points of the bad in order to achieve safe positions at therapeutic angles, which improve the breathing-perfusion (blood flow) relationship. This system also makes it possible to apply vibration waves to the patient which favor the elimination of bronchial-pulmonary secretions, the rehabilitation of the bedridden patient and decrease the work load for nursing personnel.

  18. A Tire-Sulfur Hybrid Adsorption Denitrification (T-SHAD) process for decentralized wastewater treatment.

    Science.gov (United States)

    Krayzelova, Lucie; Lynn, Thomas J; Banihani, Qais; Bartacek, Jan; Jenicek, Pavel; Ergas, Sarina J

    2014-09-15

    Nitrogen discharges from decentralized wastewater treatment (DWT) systems contribute to surface and groundwater contamination. However, the high variability in loading rates, long idle periods and lack of regular maintenance presents a challenge for biological nitrogen removal in DWT. A Tire-Sulfur Hybrid Adsorption Denitrification (T-SHAD) process was developed that combines nitrate (NO3(-)) adsorption to scrap tire chips with sulfur-oxidizing denitrification. This allows the tire chips to adsorb NO3(-) when the influent loading exceeds the denitrification capacity of the biofilm and release it when NO3(-) loading rates are low (e.g. at night). Three waste products, scrap tire chips, elemental sulfur pellets and crushed oyster shells, were used as a medium in adsorption, leaching, microcosm and up-flow packed bed bioreactor studies of NO3(-) removal from synthetic nitrified DWT wastewater. Adsorption isotherms showed that scrap tire chips have an adsorption capacity of 0.66 g NO3(-)-N kg(-1) of scrap tires. Leaching and microcosm studies showed that scrap tires leach bioavailable organic carbon that can support mixotrophic metabolism, resulting in lower effluent SO4(2-) concentrations than sulfur oxidizing denitrification alone. In column studies, the T-SHAD process achieved high NO3(-)-N removal efficiencies under steady state (90%), variable flow (89%) and variable concentration (94%) conditions.

  19. Dispersion of chitosan on perlite for enhancement of copper(II) adsorption capacity.

    Science.gov (United States)

    Hasan, Shameem; Ghosh, Tushar K; Viswanath, Dabir S; Boddu, Veera M

    2008-04-01

    Chitosan coated perlite beads were prepared by drop-wise addition of slurry, made of chitosan dissolved in oxalic acid and perlite, to an alkaline bath (0.7 M NaOH). The beads that contained 32% chitosan enhanced the accessibility of OH and amine groups present in chitosan for adsorption of copper ions. The experiments using Cu(II) ions were carried out in the concentration range of 50-4100 mg/L (0.78-64.1 mmol/L). Adsorption capacity for Cu(II) was pH dependent and a maximum uptake of 104 mg/g of beads (325 mg/g of chitosan) was obtained at pH 4.5 when its equilibrium concentration in the solution was 812.5 mg/L at 298 K. The XPS and TEM data suggested that copper was mainly adsorbed as Cu(II) and was attached to amine groups. The adsorption data could be fitted to one-site Langmuir adsorption model. Anions in the solution had minimal effect on Cu(II) adsorption by chitosan coated perlite beads. EDTA was used effectively for the regeneration of the bed. The diffusion coefficient of Cu(II) onto chitosan coated beads was calculated from the breakthrough curve and was found to be 2.02 x 10(-8) cm(2)/s.

  20. A Tire-Sulfur Hybrid Adsorption Denitrification (T-SHAD) process for decentralized wastewater treatment.

    Science.gov (United States)

    Krayzelova, Lucie; Lynn, Thomas J; Banihani, Qais; Bartacek, Jan; Jenicek, Pavel; Ergas, Sarina J

    2014-09-15

    Nitrogen discharges from decentralized wastewater treatment (DWT) systems contribute to surface and groundwater contamination. However, the high variability in loading rates, long idle periods and lack of regular maintenance presents a challenge for biological nitrogen removal in DWT. A Tire-Sulfur Hybrid Adsorption Denitrification (T-SHAD) process was developed that combines nitrate (NO3(-)) adsorption to scrap tire chips with sulfur-oxidizing denitrification. This allows the tire chips to adsorb NO3(-) when the influent loading exceeds the denitrification capacity of the biofilm and release it when NO3(-) loading rates are low (e.g. at night). Three waste products, scrap tire chips, elemental sulfur pellets and crushed oyster shells, were used as a medium in adsorption, leaching, microcosm and up-flow packed bed bioreactor studies of NO3(-) removal from synthetic nitrified DWT wastewater. Adsorption isotherms showed that scrap tire chips have an adsorption capacity of 0.66 g NO3(-)-N kg(-1) of scrap tires. Leaching and microcosm studies showed that scrap tires leach bioavailable organic carbon that can support mixotrophic metabolism, resulting in lower effluent SO4(2-) concentrations than sulfur oxidizing denitrification alone. In column studies, the T-SHAD process achieved high NO3(-)-N removal efficiencies under steady state (90%), variable flow (89%) and variable concentration (94%) conditions. PMID:24922353