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The lab-scale experiments were carried out in order to determine the effectiveness of CO2 capture from gases in the sodium hydroxide solutions under approximately standard conditions. The flow rate of the carrier gas was 140 l/min, and the CO2 content was 15%.The absorber was Dreschel washer with NaOH solution. The efficiency of CO2 capture of 85% was obtained for 50% of NaOH. It was proved that the increase of temperature in NaOH solution improves CO2 capture efficiency. The efficiency of capturing CO2 in 1 mol/l sodium carbonate was defined as 4-5%. The products of CO2 reactions in sorption solutions were marked. [ABSTRACT FROM AUTHOR]

In the present study, Quantitative Structure-Activity Relationship (QSAR) and Linear Solvation Energy Relationship (LSER) techniques were used to develop predictive models for adsorption of organic contaminants by multi-walled carbon nanotubes (MWCNTs). Adsorption data for 29 aromatic compounds from literature (i.e., the training data) including some of the experimental results obtained in our laboratory were used to develop predictive models with multiple linear regression analysis. The generated QSAR (r2 = 0.88), and LSER (r2 = 0.83) equations were validated externally using an independent validation data set of 30 aromatic compounds. External validation accuracies indicated the success of parameter selection, data fitting ability, and the prediction strength of the developed models. Finally, the combination of training and validation data were used to obtain a combined LSER equation (r2 = 0.83) that would be used for predicting adsorption of a wide range of low molecular weight aromatics by MWCNTs. In addition, LSER models at different concentrations were generated, and LSER parameter coefficients were examined to gain insights to the predominant adsorption interactions of low molecular weight aromatics on MWCNTs. The molecular volume term (V) of the LSER model was the most influential descriptor controlling adsorption at all concentrations. At higher equilibrium concentrations, hydrogen bond donating (A) and hydrogen bond accepting (B) terms became significant in the models. The results demonstrate that successful predictive models can be developed for the adsorption of organic compounds by CNTs using QSAR and LSER techniques. [ABSTRACT FROM AUTHOR]

Abstract: We have performed density functional theory calculations to understand the initial growth of graphene by studying the adsorption of carbon atoms on the oxide substrates such as magnesium oxide. For adsorption behaviors of carbon atoms on the MgO(100) surface, their adsorption geometries and binding energies are calculated. The binding of a carbon atom is the most stable at the on-top oxygen site on MgO(100). Such strong C–O binding is analyzed by examining the projected density of states. Then, we also increase the number of carbon atoms on MgO(100) to investigate their adsorption behaviors. Due to strong binding between carbon atoms, adsorbed carbon atoms form chain-like or graphene-like structures on the surface. Combined with relatively strong C–O binding, this result may explain the graphene growth on MgO(100) observed in available experiments. [Copyright &y& Elsevier]

Abstract: The kinetic and mechanistic profiles of three pharmaceutical spherical carbon adsorbents, Kremezin as the brand product and two generics (Merckmezin and spherical carbon adsorbent “Mylan”), were compared. Five non-ionic active pharmaceutical ingredients with molecular weights of 136.1–424.1Da were used as adsorbates. The results of Boehm titration, the standard method to qualify acidic or basic functional groups on a carbon surface, suggested distinctly different quantitative characteristics of each functional group among the three adsorbents. But those differences do not affect the adsorption to non-ionic adsorbates. The amount of theophylline adsorbed at equilibrium and surface area well correlated, suggesting that adsorptive ability was defined by surface area. In the tested molecular weight range, the order in terms of adsorption kinetics was spherical carbon adsorbent “Mylan”>Kremezin>Merkmezin. The adsorption profile in the equilibrium and kinetic experiments, and the lack of an effect of pH on adsorption quantity suggested that the mechanism of adsorption for non-ionic substances to be Langmuir type monolayer adsorption. Kremezin and spherical carbon adsorbent “Mylan” are more likely to adsorb co-administered drugs than Merckmezin. [Copyright &y& Elsevier]

Traditional gas and particle phase chemical markers used to identify the presence of biomass burning (BB) emissions were measured for a large forest fire near Boulder, Colorado. Correlation of the organic matter mass spectroscopic m/z 60 with measured particle light absorption properties found no link at 532 nm, and a strong correlation at 404 nm. Non-black carbon absorption at 404 nm was well correlated to the ratio of the mass fractions of particulate organic matter (POM) that was m/z 60 (f60) to m/z 44 (f44). The f60 to f44 ratio did not fully explain the variability in non-BC absorption, due to contributions of brown carbon (BrC) absorption and absorption due to internal mixing of POM with black carbon (BC). The absorption A° ngstrom exponent (°AAbs) showed a good correlation to f60/f44; however the best correlation resulted from the mass absorption efficiency (MAE) of BrC at 404 nm (MAEPOM-404 nm) and f60/f44. This result indicates that the absorption of POM at low visible and UV wavelengths is linked to emissions of organic matter that contribute to the m/z 60 mass fragment, although they do not contribute to 532 nm absorption. m/z 60 is often attributed to levoglucosan and related compounds. The linear relationship between MAEPOM-404 nm and f60/f44 suggests that the strength of BrC absorption for this fire can be predicted by emissions of f60-related organic matter. [ABSTRACT FROM AUTHOR]

Abstract: Phenol–formaldehyde resins and a low-cost biomass residue, olive stones (OS), were used to prepare five activated carbons for CO2 separation at atmospheric pressure, i.e., in post-combustion processes or from biogas and bio-hydrogen streams. Two phenol–formaldehyde resins were synthesized: Resol, obtained by using alkaline environment, and Novolac, synthesized in the presence of an acid catalyst. Carbon precursors were prepared by mixing both resins with KCl or by mixing the Novolac resin with OS. The precursors were carbonized under an inert atmosphere of N2 at different temperatures. The last stage in the synthesis of the adsorbents involved physical activation with carbon dioxide, which was carried out at different temperatures and burn-off degrees. Response surface methodology (RSM) is proposed as a tool for rapidly optimizing the activation parameters in order to obtain the highest possible CO2 capture capacity of activated carbons. The optimum values of activation temperature and burn-off degree that maximize CO2 uptake by the activated carbons at 35°C and atmospheric pressure were obtained within the experimental region. A value of CO2 adsorption capacity of 9.3wt.% was achieved. Activated carbons derived from the Novolac phenol–formaldehyde resin type and from OS showed great potential as adsorbents for CO2 capture at atmospheric pressure. [Copyright &y& Elsevier]

Abstract: The adsorption energies, structural, electrical and magnetic properties of adsorption of C and CO on the fcc Co (110) surface have been investigated using density functional theory. The preferential adsorption site for the fcc Co (110) has been calculated. For the case of C adsorption, the preferential adsorption site is the long-bridge for both the 0.5 and 1.0 monolayers (ML) coverages. Whilst for the CO case, the preferential adsorption sites are at the atop and short-bridge site for 0.5 and 1.0 ML coverages respectively. Structurally, the first two layers of the bare Co (110) surface expand whereas the second and third layers contract. Upon adsorption of either C or CO, however, the degree of expansion and compression reduces. Magnetically, the adsorbates were found to couple ferrimagnetically to the surface and suppress the magnetic moment of the Co layers beneath them. The C adsorbate has a much stronger suppression effect as compared to the CO adsorbate. At 0.5 ML coverage, the C adatom suppresses up to 47% of the magnetic moment in the surface layer compared to a clean Co (110), whereas the CO adsorbate only suppresses up to 16%. For the 1.0 ML coverage case, both the C and CO adsorbates suppress almost equivalently well at 68% and 63% respectively. We also report on a correlation between the amount of charge transfer and the degree of suppression of the surface magnetic moment. Finally, we observe that the electronic charge is shared in the [001] direction for the C adsorbate and in the [10] direction for the CO adsorbate. This anisotropy of surface bonding, in conjunction with the ligand field theory, explains the mechanism behind the spin reorientation transition that occurs uniquely on the CO/Co(110) system. [Copyright &y& Elsevier]

Abstract: The consequences of groundwater contamination can remain long after a contaminant source has been removed. Documentation of natural aquifer recoveries and empirical tools to predict recovery time frames and associated geochemical changes are generally lacking. This study characterized the long-term natural attenuation of a groundwater contaminant plume in a sand and gravel aquifer on Cape Cod, Massachusetts, after the removal of the treated-wastewater source. Although concentrations of dissolved organic carbon (DOC) and other soluble constituents have decreased substantially in the 15years since the source was removed, the core of the plume remains anoxic and has sharp redox gradients and elevated concentrations of nitrate and ammonium. Aquifer sediment was collected from near the former disposal site at several points in time and space along a 0.5-km-long transect extending downgradient from the disposal site and analyses of the sediment was correlated with changes in plume composition. Total sediment carbon content was generally low (<8 to 55.8μmol (g dry wt)−1) but was positively correlated with oxygen consumption rates in laboratory incubations, which ranged from 11.6 to 44.7nmol (g dry wt)−1 day−1. Total water extractable organic carbon was <10–50% of the total carbon content but was the most biodegradable portion of the carbon pool. Carbon/nitrogen (C/N) ratios in the extracts increased more than 10-fold with time, suggesting that organic carbon degradation and oxygen consumption could become N-limited as the sorbed C and dissolved inorganic nitrogen (DIN) pools produced by the degradation separate with time by differential transport. A 1-D model using total degradable organic carbon values was constructed to simulate oxygen consumption and transport and calibrated by using observed temporal changes in oxygen concentrations at selected wells. The simulated travel velocity of the oxygen gradient was 5–13% of the groundwater velocity. This suggests that the total sorbed carbon pool is large relative to the rate of oxygen entrainment and will be impacting groundwater geochemistry for many decades. This has implications for long-term oxidation of reduced constituents, such as ammonium, that are being transported downgradient away from the infiltration beds toward surface and coastal discharge zones. [Copyright &y& Elsevier]

Determination of 5-d biochemical oxygen demand (BOD5) is the most commonly practiced test to assess the water quality of surface waters and the waste loading. However, BOD5 is not a good parameter for the control of water or wastewater treatment processes because of its long test period. It is very difficult to produce consistent and reliable BOD5 results without using careful laboratory quality control practices. This study was performed to develop software sensors to predict the BOD5 of river water and wastewater. The software sensors were based on the multiple regression analysis using the dissolved organic carbon (DOC) concentration, UV light absorbance at 254 nm, and synchronous fluorescence spectra. River water samples and wastewater treatment plant (WWTP) effluents were collected at 1-hour interval to evaluate the feasibility of the software sensors. In short, the software sensors developed in this study could well predict the BOD5 of river water (r = 0.78) and for the WWTP effluent (r = 0.90). [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the removal of Remazol Yellow dye from aqueous solutions by adsorption on activated carbon prepared by chemical activation of sunflower seed cake. It was found that the carbon content of biomass increases up to 65.12% after activation and carbonization processes. The maximum percentage dye removal was obtained as 82.12% with 0.4 g/50 mL adsorbent dosage at 313 K. The Langmuir model showed the best fit with equilibrium isotherm data. The interactions were evaluated with respect to both pseudo-first-order and pseudo-second-order reaction kinetics. The adsorption process was found to follow the pseudo-second-order model. To optimize the operating conditions, the effects of pH, adsorbent dosage, and initial dye concentration were investigated by full factorial experimental design method; adsorbent dosage was found as the most significant factor with P = 0.02 lower than 95% confidence level. The obtained results are very promising since (i) the utilization of sunflower seed cake activated carbon (SSCAC) played a critical role in the adsorption of dye; (ii) sunflower seed cake was an intriguing, low-cost, and easily available material. It can be an alternative adsorbent precursor for more expensive adsorbents used for Remazol Yellow (RY) removal. [ABSTRACT FROM AUTHOR]

Adsorption of β-carotene on mesoporous carbon coated monolith (MCCM) from methyl ester as a solvent was investigated. Kinetics and thermodynamics parameters have been evaluated. Maximum β-carotene adsorption capacity was 22.37 mg/g at 50 °C. Process followed Langmuir isotherm. The adsorption was endothermic and spontaneous. Contact time studies showed increase in adsorption capacity with increase in β-carotene initial concentration and temperature. Pseudo-secondorder model was applicable to the experimental data. The value of activation energy confirmed physical adsorption process. [ABSTRACT FROM AUTHOR]

Abstract: Mesoporous magnetic Co-NPs(nanoparticles)/carbon nanocomposites were synthesized by carbonization of polyacrylonitrile (PAN) microspheres entrapped with cobalt salt for the first time. The structure and morphology of the porous magnetic nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), and N2 adsorption–desorption technique. The nanocomposites possess very high saturation magnetization (Ms is up to ∼133emu/g), near-zero remanence, and very low coercivity (Hc is down to ∼0.023KOe). Meanwhile, the nanocomposites have mesoporous structure with average pore size of 4nm and high specific surface area of 232m2/g, which can be tuned by changing the carbonization conditions. Using methyl orange (MO) as model pollutant in water, the mesoporous magnetic nanocomposites showed good adsorption capacity of 380mg/g, and the absorbed MO could be easily released in ethanol. The mesoporous nanocomposites were facile separated from solution under external magnetic force, and over 85% adsorption capacity for MO could be retained after five adsorption/desorption cycles. [Copyright &y& Elsevier]

The influences of temperature, manganese, and carbon on the surface tension of liquid ternary Fe-Mn-C systems were investigated. The measurements were carried out with the sessile drop method in the temperature range of 1653-1834 K. The manganese and carbon contents were changed between 4.79-9.89 and 1.07-4.20 wt%, respectively. It was demonstrated that the surface tension varied as a linear function of temperature for all the examined samples. With increasing manganese content, the surface tension decreased. When the weight fraction of manganese with respect to iron was fixed, the surface tension decreased with increasing carbon content. From thermodynamic consideration, it was considered that carbon preferentially adsorbed on the metal surface as carbon atoms rather than manganese carbide. [ABSTRACT FROM AUTHOR]

Abstract: The liquid phase adsorption equilibrium and kinetics of three paraffins onto a carbon molecular sieve at a temperature of 30°C were obtained, namely n-heptane (nC7), 2-methylheptane (2MC7), and 2,5-dimethylhexane (25DMC6), as well as a mixture of these three components in a non-adsorbing 2,2,4-trimethylpentane (224TMC5) solvent. The adsorption capacities of the individual hydrocarbons ranged from 1.6 to 2.3mmol/gads. The total adsorption capacity of the molecular sieve in the tri-component mixture was 2.0–2.1mmol/gads, where the individual adsorption capacity of the nC7, the 2MC7 and the 25DMC6 was approximately 0.9, 0.7 and 0.4mmol/gads, respectively, with small variations depending on the initial concentration of the hydrocarbons. The combined results were modeled as a dual-site Langmuir kinetic model where two consecutive adsorption processes were considered, namely the non-selective adsorption of molecules in the meso-supermicropores, followed by the movement of these adsorbed molecules into even smaller pores through the barriers of the micropore mouths. The results obtained in this study showed that the selective part of the adsorption process was crucial for achieving the observed kinetic separation, and the model could be used to satisfactorily describe the observed adsorption. [Copyright &y& Elsevier]

Ocean acidification may stimulate primary production through increased availability of inorganic carbon in the photic zone, which may in turn change the biogenic flux of dissolved organic carbon ( DOC) and the growth potential of heterotrophic bacteria. To investigate the effects of ocean acidification on marine bacterial assemblages, a two-by-three factorial mescosom experiment was conducted using surface sea water from the East Greenland Current in Fram Strait. Pyrosequencing of the V1- V2 region of bacterial 16S ribosomal RNA genes was used to investigate differences in the endpoint (Day 9) composition of bacterial assemblages in mineral nutrient-replete mesocosms amended with glucose (0 μ m, 5.3 μ m and 15.9 μ m) under ambient (250 μatm) or acidified (400 μatm) partial pressures of CO2 ( p CO2). All mesocosms showed low richness and diversity by Chao1 estimator and Shannon index, respectively, with general dominance by Gammaproteobacteria and Flavobacteria. Nonmetric multidimensional scaling analysis and two-way analysis of variance of the Jaccard dissimilarity matrix (97% similarity cut-off) demonstrated that the significant community shift between 0 μ m and 15.9 μ m glucose addition at 250 μatm p CO2 was eliminated at 400 μatm p CO2. These results suggest that the response potential of marine bacteria to DOC input may be altered under acidified conditions. [ABSTRACT FROM AUTHOR]

Abstract: In this study, various physicochemical characteristics were evaluated for three pharmaceutical spherical carbon adsorbents, Kremezin as a brand product and its generics; Merckmezin and Spherical Carbon Adsorbent “Mylan”. Scanning electron microscopic observations, measurements of specific surface area, particle sizes, and pore volume distributions by mercury intrusion porosimetry, and dynamic vapor sorption (DVS) analysis were conducted. Compared to Kremezin, Merckmezin is dented with a small pore-rich structure; pores of less than 10nm make up 43% (Kremezin) and 68% (Merckmezin) of total pore volume. On the other hand, Spherical Carbon Adsorbent “Mylan” is porous with macropores. The results of fractal dimension analysis of micropores suggested that the complexity of the internal pore structure is Merckmezin>Kremezin≫Spherical Carbon Adsorbent “Mylan”. The three spherical carbon adsorbents are physico-chemically different, but clinical studies should be conducted to prove that they are therapeutically equivalent. [Copyright &y& Elsevier]

Abstract: Oil exposure has been shown to be detrimental to several salt marsh plants however little information is available for Juncus roemerianus. Thirty-two mesocosms were established with J. roemerianus sod and replicate marshes were exposed to Louisiana sweet crude oil to test oil dose (6, 12, and 24Lm−2) and weathering (oil weathered for 0days, 3days, and 3weeks). Juncus were monitored following oil exposure for culm survival, photosynthetic rates, and C-assimilation rates. Oil dosage had a significant effect among wetlands with low-dose (6Lm−2) mesocosms having higher culm survival, photosynthetic rates, and C-assimilation rates than medium or high dose wetlands (12 or 24Lm−2). Oil weathering did not elicit significant differences between treated wetlands however full strength wetlands (un-weathered oil) consistently had the lowest culm survivorship, photosynthetic rates, and C-assimilation rates. From our results, J. roemerianus marshes may be very susceptible to oil exposure. [Copyright &y& Elsevier]

Abstract: This study assesses the full cycle transport and fate of a polychlorinated biphenyl (PCB) congener spiked to sediment to empirically and spectroscopically investigate the effects of sediment ageing and organic carbon on the adsorption, desorption, and reaction of the PCB. Caesar Creek sediment (CCS) was oxidized to remove amorphous organic carbon (AOC) followed by soot carbon (SC), spiked and aged with 2-chlorobiphenyl (2-ClBP), mixed with various aquatic solutions, and treated on reactive activated carbon (RAC) impregnated with palladized iron. Results showed that 2-ClBP sorption isotherms and kinetic parameters well reflected the critical influence of AOC and SC on the sorption behavior of 2-ClBP. Infrared analysis implied the presence of preferred 2-ClBP sorption sites within the sediment matrix. The shift in the Conal frequencies of 2-ClBP bound to CCS was more apparent in cases of higher organic content (particularly SC) and longer ageing time, which made 2-ClBP more sorbed and strongly bound to CCS and thus made it more difficult to desorb 2-ClBP. The ageing effect on 2-ClBP binding was more prominent in the presence of organic carbon. Only desorbed 2-ClBP was transported to the target RAC for its physical adsorption and chemical dechlorination. [Copyright &y& Elsevier]

The adsorption of buckminsterfullerene (C) on metal surfaces has been investigated extensively for its unique geometric and electronic properties. The two-dimensional systems formed on surfaces allow studying in detail the interplay between bonding and electronic structures. Recent studies reveal that C adsorption induces reconstruction of even the less-reactive close-packed metal surfaces. First-principles computations enable access to this important issue by providing not only detailed atomic structure but also electronic properties of the substrate-adsorbate interaction, which can be compared with various experimental techniques to determine and understand the interface structures. This review discusses in detail the ordered phases of C monolayers on metal surfaces and the surface reconstruction induced by C adsorption, with an emphasis on the different types of reconstruction resulting on close-packed metal surfaces. We show that the symmetry matching between C molecules and metal surfaces determines the local adsorption configurations, while the size matching between C molecules and the metal surface lattice determines the supercell sizes and shapes; importantly and uniquely for C, the number of surface metal atoms within one supercell determines the different types of reconstruction that can occur. The atomic structure at the molecule-metal interface is of crucial importance for the monolayer's electronic and transport properties: these will also be discussed for the well-defined adsorption structures, especially from the perspective of tuning the electronic structure via C-metal interface reconstruction and via relative inter-C orientations. [ABSTRACT FROM AUTHOR]

Shelves have been estimated to account for more than one fifth of the global marine primary production. It has been also conjectured that shelves strongly influence the oceanic absorption of atmospheric CO2 (carbon shelf pump). Owing to their coarse resolution, currently applied global climate models are inappropriate to investigate the impact of climate change on shelfs and regional models do not account for the complex interaction with the adjacent open ocean. In this study, a global ocean general circulation model and biogeochemistry model were set up with a distorted grid providing a maximal resolution for the NW European shelf and the adjacent North Atlantic. Using model climate projections we found that already a moderate warming of about 2.0 K of the sea surface is linked with a reduction by ~30% of biological production on the NW European shelf. If we consider the decline of anthropogenic riverine eutrophication since the 90's the reduction of biological production amounts to 39%. The decline of NW European shelf productivity is twice as strong as the decline in the open ocean (~15%). The underlying mechanism is a spatially well confined stratification feedback along the continental shelf break. This feedback reduces the nutrient supply from the deep Atlantic to about 50%. In turn, the reduced productivity draws down CO2 absorption on the NW European shelf by ~34% at the end of the 21st century compared to the end of the 20th century implying a strong weakening of shelf carbon pumping. Sensitivity experiments with diagnostic tracers indicate that not more than 20% of the carbon absorbed in the North Sea contributes to the long term carbon uptake of the world ocean. The rest remains within the ocean mixed layer where it is exposed to the atmosphere. The predicted decline in biological productivity and decrease of phytoplankton concentration (by averaged 25%) due to reduced nutrient imports from the deeper Atlantic will probably negatively affect the local fish stock and therefore fisheries in the North Sea. [ABSTRACT FROM AUTHOR]

A class of high-surface-area carbon hypothetical structures has been investigated that goes beyond the traditional model of parallel graphene sheets hosting layers of physisorbed hydrogen in slit-shaped pores of variable width. The investigation focuses on structures with locally planar units (unbounded or bounded fragments of graphene sheets), and variable ratios of in-plane to edge atoms. Adsorption of molecular hydrogen on these structures was studied by performing grand canonical Monte Carlo simulations with appropriately chosen adsorbent-adsorbate interaction potentials. The interaction models were tested by comparing simulated adsorption isotherms with experimental isotherms on a high-performance activated carbon with well-defined pore structure (approximately bimodal pore-size distribution), and remarkable agreement between computed and experimental isotherms was obtained, both for gravimetric excess adsorption and for gravimetric storage capacity. From this analysis and the simulations performed on the new structures, a rich spectrum of relationships between structural characteristics of carbons and ensuing hydrogen adsorption (structure-function relationships) emerges: (i) Storage capacities higher than in slit-shaped pores can be obtained by fragmentation/truncation of graphene sheets, which creates surface areas exceeding of 2600 m2/g, the maximum surface area for infinite graphene sheets, carried mainly by edge sites; we call the resulting structures open carbon frameworks (OCF). (ii) For OCFs with a ratio of in-plane to edge sites ~1 and surface areas 3800-6500 m2/g, we found record maximum excess adsorption of 75-85 g of H2/kg of C at 77 K and record storage capacity of 100-260 g of H2/kg of C at 77 K and 100 bar. (iii) The adsorption in structures having large specific surface area built from small polycyclic aromatic hydrocarbons cannot be further increased because their energy of adsorption is low. (iv) Additional increase of hydrogen uptake could potentially be achieved by chemical substitution and/or intercalation of OCF structures, in order to increase the energy of adsorption. We conclude that OCF structures, if synthesized, will give hydrogen uptake at the level required for mobile applications. The conclusions define the physical limits of hydrogen adsorption in carbon-based porous structures. [ABSTRACT FROM AUTHOR]

Inversion gas chromatography was used to determine at extremely low surface coverages the specific component Isp of the surface free energy for various types of carbon blacks. It was demonstrated that the Rohrschneider-McReynolds model can be used to evaluate the capacity of carbon adsorbents for various kinds of intermolecular interactions. [ABSTRACT FROM AUTHOR]

Carbon adsorbents with mechanical strengths of 90-93% and a micropore volume of 0.16-0.3 cm/cm have been obtained from nitrated asphaltites by the existing industrial technology. Compared to industrial carbon with the trademark KAD-iodine, medium-charred specimens are highly selective in extracting gold and silver from multicomponent polymetal solutions and have a high capacity for sorbing arsenic from waste waters. [ABSTRACT FROM AUTHOR]

This paper reports the results of investigations of an adsorption cassette consisting of a compact capacious element with a developed adsorption layer in the form of a packet of eight layers of carbon cloth of the trademark KUT-M pressed between box-shaped perforated aluminum substrates. The evacuation parameters of the cassette are determined. It is found that the operating absorption capacity is 1.7-2 times higher than the adsorption capacity of the cassette determined under isothermal conditions. It is experimentally demonstrated that the adsorbent in the cassette is effectively protected by a cylindrical shield with one-way entry which cools the elements and a face disk-like shield. [ABSTRACT FROM AUTHOR]

New phosphorus-containing carbon adsorbents have been obtained by modification of coconut shells with phosphoric acid at temperatures of 400-900 °C in a stream of argon. The carbon modified with phosphoric acid has a somewhat reduced porous structure. The presence of 4-5 types of surface group, 22-29% of which contained phosphate groups, was demonstrated by potentiometric titration. The quantity of phosphate groups increased when the temperature of the thermal treatment was increased. The phosphate-containing carbon has a greater adsorption capacity with respect to heavy metals than oxidized carbon. [ABSTRACT FROM AUTHOR]

Abstract: The present work studies the removal of indigo carmine from aqueous solutions by an electrocoagulation (EC)/granular activated carbon (GAC) adsorption coupling process. The kinetics of this coupling process was studied using several GACs and different amounts of adsorbent material in order to identify the most appropriate adsorbent and dosage, respectively, for enhancing wastewater treatment. The influence of current density on the removal efficiency and electrical operating costs of the EC/GAC coupling process was also determined. Four GAC materials, Pica F22, L27, X17 and S21, were characterized and used in the study of the EC/GAC coupling process. The textural characteristics of adsorbent materials were established based on nitrogen adsorption and their surface chemical properties were investigated by FTIR spectroscopy. The coupling between electrocoagulation and GAC showed that the addition of an appropriate GAC resulted in the enhancement of the removal rate of indigo carmine especially at lower current densities, and in a considerable reduction in the contact time compared to the conventional simple EC process and simple adsorption process. Though the F22 exhibited outstanding adsorption properties related to indigo carmine dye, Pica L27/EC coupling provided the best rate constants. Based on the significant decrease in electrical operating costs, the EC/GAC coupling method could be recommended instead of the conventional simple EC. [Copyright &y& Elsevier]

Carbon deposition and sulfur poisoning are issues that limit the state-of-the-art Ni-YSZ anode material of solid oxide fuel cell to be used in direct hydro-carbon fuels. In the present study, density functional theory calculations are performed to investigate the adsorption of C and S on Ni(111), Cu(111) and alloyed Ni-Cu(111) surfaces. It is confirmed that C and S energetically favor the hollow sites of Ni(111) and Cu(111) surfaces; forming Ni-Cu alloy by addition of Cu into Ni weakens the adsorption of C and S with lowered adsorption energies due to less overlapping between the C 2p or S 3p and the metallic 3d orbits. [ABSTRACT FROM AUTHOR]

Abstract: The effect of repeated natural resuspension on benthic oxygen consumption and the effect of natural and massive resuspension on oxygen consumption and fluxes of phosphate, silicate, ammonium and dissolved inorganic carbon (DIC) were studied at two stations (S1 and S2) in a Scottish sea loch. Station S11 had organically enriched sediment and station S1 had lower organic content in the sediment. The fluxes were measured in situ using the Göteborg benthic lander. Natural resuspension, simulating resuspension events due to strong wind, waves or currents, and massive resuspension, simulating resuspension due to e.g. trawling or dredging, were created inside the incubation chambers by regulating the stirring of the incubated overlying water or by retracting and shaking the incubated sediment. Natural resuspension showed clear effects on the oxygen consumption at station S11, where it increased with an average of 12.8 (standard error (s.e.) 0.17) and 7.7 (s.e. 0.12) mmolm−2 d−1 during the first and second incubations, respectively. At station S1 there was no clear effect of natural resuspension on the oxygen consumption. Massive resuspension increased the oxygen consumption on S1 with an average of 608 (standard deviation (sd) 366) mmolm−2 d−1 and on S11 with an average of 2396 (sd 2265) mmolm−2 d−1. The fluxes of ammonium, phosphate and silicate were affected by the massive resuspension in 50, 14 and 33% of the chambers, respectively, on station S11. However, in the majority of the cases there were no effects on the nutrient and DIC fluxes of massive resuspension. The absolute concentrations of DIC, ammonium and silicate did however instantly increase with an average of 419 (sd 297), 48 (sd 27) and 6.9 (sd 3.7) μM, respectively, at S11 upon massive resuspension. The concentrations of phosphate decreased instantly with an average of 0.2 (sd 0.1) μM. On station S1 there were effects only on the ammonium and silicate concentrations, which increased with 0.8 (sd 0.3) and 1.13 (sd 0.36) μM, respectively. The large increase in oxygen consumption due to massive resuspension indicates that activities like e.g. trawling and dredging that take place in areas where water exchange occurs infrequently may lead to oxygen depletion in bottom water, which in turn might affect the ecological balance. Silicate, ammonium and DIC can be released due to massive resuspension and contribute to increased algal blooms in surface waters. [Copyright &y& Elsevier]

The purpose of this study was to determine the possibility of producing hydrophobic mesoporous mineral-carbon sorbents from aluminum hydroxide and coal-tar pitch-polymer compositions by carbonization at 600 °C in an nitrogen atmosphere. The method of homogenization was optimized using different solvents. Blends of aluminum hydroxide and coal-tar pitch with a definite composition or the products of co-precipitation of aluminum hydroxide in the coal-tar pitch-polymer medium were subjected to carbonization process. The hydrophilic-hydrophobic properties were evaluated by adsorption of water vapors. The highest value of BET surface area about 370 m/g, was achieved for the carbonization product obtained from co-precipitated raw components with 10 wt% coal-tar pitch-polymer compositions. [ABSTRACT FROM AUTHOR]

Abstract: The liquid adsorption and surface properties of two carbon blacks (CBs), one was as-received and one was oven-dried, were studied by the capillary rise method. Taking these two CBs to adsorb two polar liquids, water and formamide, and two non-polar liquids, hexane and diiodomethane, respectively, we found that both CBs, especially the oven-dried CB, has a higher adsorption for non-polar liquid and a smaller one for the polar liquids. According to furthermore deduced surface free energy data, we further found that both CBs, especially the oven-dried CB, are stronger in the Lewis acid and weaker in the Lewis base, and the total surface free energies are contributed by the Lifshitz–van der Waals interaction component, especially for oven-dried CB up to about 90%. For oven-dried CB, its surface free energy was found lower at about 20–21mJ/m2. [Copyright &y& Elsevier]

Abstract: In this paper, the low temperature electrical conductivity and microwave absorption properties of carbon coated iron nanoparticles–polyvinyl chloride composite films are investigated for different filler fractions. The filler particles are prepared by the pyrolysis of ferrocene at 980°C and embedded in polyvinyl chloride matrix. The high resolution transmission electron micrographs of the filler material have shown a 5nm thin layer graphitic carbon covering over iron particles. The room temperature electrical conductivity of the composite film changes by 10 orders of magnitude with the increase of filler concentration. A percolation threshold of 2.2 and an electromagnetic interference shielding efficiency (EMI SE) of ∼18.6dB in 26.5–40GHz range are observed for 50wt% loading. The charge transport follows three dimensional variable range hopping conduction. [Copyright &y& Elsevier]

Purpose: The aim of this study is to use life cycle assessment (LCA) to compare the relative environmental performance of the treatment using Trametes versicolor with a common method such as activated carbon adsorption. This comparison will evaluate potential environmental impacts of the two processes. This work compiles life cycle inventory data for a biological process that may be useful for other emergent biotechnological processes in water and waste management. LCA was performed to evaluate the use of a new technology for the removal of a model metal-complex dye, Grey Lanaset G, from textile wastewater by means of the fungus T. versicolor. This biological treatment was compared with a conventional coal-based activated carbon adsorption treatment to determine which alternative is preferable from an environmental point of view. Materials and methods: The study is based on experimental research that has tested the novel process at the pilot scale. The analysis of the biological system ranges from the production of the electricity and ingredients required for the growth of the fungus and ends with the composting of the residual biomass from the process. The analysis of the activated carbon system includes the production of the adsorbent material and the electricity needed for the treatment and regeneration of the spent activated carbon. Seven indicators that measure the environmental performance of these technologies are included in the LCA. The indicators used are climate change, ozone depletion, human toxicity, photochemical oxidant formation, terrestial acidification, freshwater eutrophication, marine eutrophication, terrestrial ecotoxicity, freshwater ecotoxicity, marine ecotoxicity, metal depletion and fossil depletion. Results: The results show that the energy use throughout the biological process, mainly for sterilisation and aeration, accounts for the major environmental impacts with the inoculum sterilisation being the most critical determinant. Nevertheless, the biological treatment has lower impacts than the physicochemical system in six of these indicators when steam is generated directly on site. A low-grade carbon source as an alternative to glucose might contribute to reduce the eutrophication impact of this process. Conclusions: The LCA shows that the biological treatment process using the fungus T. versicolor to remove Grey Lanaset G offers important environmental advantages in comparison with the traditional activated carbon adsorption method. This study also provides environmental data and an indication of the potential impacts of characteristic processes that may be of interest for other applications in the field of biological waste treatment and wastewater treatment involving white-rot fungi. [ABSTRACT FROM AUTHOR]

Nanoparticles (NPs) are emerging as a new type of contaminant in water and wastewater. The fate of titanium dioxide nanoparticles (TiONPs) in a granular activated carbon (GAC) adsorber and their impact on the removal of trichloroethylene (TCE) was investigated. Key parameters governing the TiONP-GAC interaction such as specific surface area (SSA), zeta potential, and the TiONP particle size distribution (PSD) were determined. The impact of TiONPs on TCE adsorption on GAC was tested by conducting TCE adsorption isotherm, kinetic, and column breakthrough studies in the presence and absence of TiONPs. SSA and pore size distribution of the virgin and spent GAC were obtained. The fate and transport of the TiONPs in the GAC fixed bed and their impact on TCE adsorption were found to be a function of their zeta potential, concentration, PSD, and the nature of their aggregation. The TiONPs under investigation are not stable in water and rapidly form larger aggregates. Due to the fast adsorption kinetics of TCE, the isotherm and kinetic studies found no effect from TiONPs. However, TiONPs attached to GAC and led to a reduction in the amount of TCE adsorbed during the breakthrough experiments suggesting a preloading pore blockage phenomenon. The analysis of the used GAC confirmed the pore blockage and SSA reduction. [ABSTRACT FROM AUTHOR]

Abstract: Equilibrium adsorption of thiophenic sulfur compounds, thiophene (T), benzothiophene (BT), and dibenzothiophene (DBT), from their binary solutions in n-octane and ternary solutions in n-octane and benzene, on three sorbents (activated carbon (AC), AgNO3/MCM-41 and Cu(I)–Y) were studied systematically. Fixed-bed adsorption/breakthrough experiments on these sorbents were also carried out. For all thiophenic sulfur compounds in both binary and ternary solutions, the sorbent adsorption capacities followed the order: Cu(I)–Y>AgNO3/MCM-41>AC. For each sorbent, the selectivity of adsorption of thiophenic sulfur compounds from liquid solutions followed the order: DBT>BT>T>benzene. The experimental results were well interpreted by molecular orbital calculation results. For ternary solutions, benzene competed against thiophenic sulfur compounds for adsorption sites, resulting in reduced thiophenic sulfur adsorption on the studied sorbents. Based on the single-solute Langmuir–Freundlich isotherms, the extended Langmuir–Freundlich isotherm (for multi-component equilibrium adsorption) was used to predict adsorption in ternary solutions, which was in fair agreement with the experimental results. The Cu(I)–Y sorbent was fully regenerable. [Copyright &y& Elsevier]

Abstract: A nitrogen-rich carbon with a hierarchical micro-mesopore structure was obtained through pyrolysis of a porous polymer prepared from terephthalaldehyde and melamine, and then investigated for CO2 capture. This nitrogen-rich porous carbon exhibited a CO2 uptake of 141mg/g at 25°C, 1atm, which is one of the highest CO2 capture capacities among carbon materials reported to date under these conditions. Excellent separation selectivity against N2 (CO2/N2 selectivity of ca. 32) was achieved. Also, fast adsorption–desorption kinetics were exhibited, and adsorbent regeneration was achieved by a simple helium purge at 25°C. Ten consecutive adsorption–desorption test cycles established the material’s excellent stability as a CO2 adsorbent. These outstanding features as a CO2 adsorbent were mostly attributed to the material’s high content of basic nitrogen species, in addition to its physical properties (high surface area and hierarchical micro-mesoporosity). [Copyright &y& Elsevier]

Abstract: Wood sawdust was converted into a high-quality activated carbon (WSAC) via microwave-induced K2CO3 activation. The operational variables including chemical impregnation ratio, microwave power and irradiation time on the carbon yield and adsorption capability were identified. The surface physical characteristics of WSAC were examined by pore structural analysis, scanning electron microscopy and nitrogen adsorption isotherms. The adsorptive behavior of WSAC was quantified using methylene blue as model dye compound. The best conditions resulted in activated carbon with a monolayer adsorption capacity of 423.17mg/g and carbon yield of 80.75%. The BET surface area, Langmuir surface area and total pore volume were corresponded to 1496.05m2/g, 2245.53m2/g and 0.864cm3/g, respectively. The findings support the potential to prepare high surface area and mesoporous activated carbon from wood sawdust by microwave assisted chemical activation. [Copyright &y& Elsevier]

This paper describes the design and performance of a photo-acoustic aerosol absorption spectrometer (PAS) built for operation on a research aircraft platform. The PAS instrument is capable of measuring dry absorption at 659 nm, 532 nm, and 404 nm, and absorption enhancement due to coatings at 532 nm and 404 nm. The measurement accuracy for all channels is < = 10% and in flight 1 Hz sensitivities lie within the range of 0.5–1.5 Mm−1. PAS measurements of calibrated absorbing aerosol samples are shown to be consistent with measurements made by a previous generation single channel photo-acoustic instrument. Aircraft data collected during a recent field campaign in California are used to demonstrate the capabilities of the PAS. In combination with an aircraft cavity ring down aerosol extinction spectrometer described in a companion paper, the new PAS instrument provides a sensitive airborne in-situ characterization of aerosol optics. Copyright 2012 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

Abstract: A simple route has been developed to synthesize magnetic Ni-containing ordered mesoporous carbons (Ni/OMCs) without using a solvent for dissolving carbon precursor or magnetic source. The adsorption and desorption of methylene orange (MO) on the obtained Ni/OMCs were investigated. The effects of Ni(NO3)2 loading amount and carbonization temperature on the morphologies, the structural parameters and magnetic properties of these Ni/OMCs were evaluated by X-ray diffraction(XRD), N2 sorption analysis, transmission electron microscopy(TEM) and physical property measurements. With the increase of Ni(NO3)2 loading amount, the ordering of the mesoporous structures, the specific surface area and the total pore volumes of Ni/OMCs decreased, but the pore diameters of Ni/OMCs and the sizes of Ni particle increased. The saturation magnetization strength could be easily adjusted by varying the amount of Ni(NO3)2. The specific surface area and total pore volumes decreased with the increasing of carbonization temperature. The size of Ni particle was the biggest at 750°C. The adsorption of MO into Ni/OMCs followed the Sips adsorption model. More interestingly, a simple equation was obtained and was proved to well fit the desorption behavior of MO on Ni/OMCs. The values for the relative fitted parameters were obtained and the physical meanings of the parameters were well defined. [Copyright &y& Elsevier]

Abstract: In this comparative study, the application of response surface methodology (RSM) in predicting and optimizing the amination conditions of activated carbon adsorbent toward CO2 adsorption was investigated. The adsorbents were prepared based on the central composite design (CCD) with three independent variables (i.e., amination temperature, amination time, and the use of pre-heat treated (HTA) or pre-oxidized (OXA) sorbent as the starting material), and the responses studied were CO2 adsorption and desorption capacity. Two quadratic models were developed to calculate the optimum amination conditions of activated carbon that provide a compromise between the studied responses (dependent variables). From the analysis of variance (ANOVA), the temperature of ammonia treatment was found to be the most important factor; it had a positive influence on CO2 adsorption capacity but a negative effect on desorption capacity. The optimal point indicated by numerical optimization corresponded to an OXA sorbent that had been aminated at 425°C for 2.1h. The activated carbon modified at optimum conditions had a CO2 adsorption capacity of 26.47mg/g and a CO2 desorption capacity of 95.4%. The experimental values of the responses were in good agreement with the amounts predicted by the regression models, indicating that the developed models could adequately predict the responses from the amination variables. The stable adsorption/desorption performance of the optimal activated carbon adsorbent during cyclical operations showed its potential for practical applications. [Copyright &y& Elsevier]

The variation in the catalytic activity of carbon black (CB) during methane decomposition was investigated by considering the number of active sites of CB. We demonstrated that the activity variation could be well estimated by assuming the edge length of graphitic sheets evolving from the CB surface. The results suggested that the activity variation originated from surface structural changes due to carbon deposition. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: Spin-polarized density functional theory calculations have been performed to investigate carbon deposition and carbide formation on Fe(100) and Fe(110) at different carbon coverage. On Fe(100) with increasing carbon coverage, the most stable carbon adsorption configuration changes from surface carbon adsorption to surface carbon diffusion into subsurface, and surface carbon clustering is not favored thermodynamically. However, surface carbon clustering is more favored kinetically than carbon diffusion; and carbon diffusion into subsurface and surface carbon clustering become competitive. On Fe(110) with increasing surface carbon coverage, the most stable adsorption configuration changes from surface carbon adsorption to surface carbon diffusion into subsurface, and this process is favored both kinetically and thermodynamically, and surface carbon clustering is neither favored nor competitive. Surface carbon deposition might form on Fe(100), while carbide formation might be found on Fe(110). [Copyright &y& Elsevier]

Reduction of a few substituted cyclohexanones adsorbed on size classified high carbon ash fractions from a stoker fired boiler of a thermal power station using NaBH4 as the reducing agent with ethanol as the medium resulted in the formation of two epimeric alcohols. However, trans-4-t-butyl and trans-4-methylcyclohexanols are exclusively formed when the corresponding ketones adsorbed on one particular size classified ash fraction are reduced with NaBH4. In all other cases, a fairly high degree of stereoselectivity has been obtained. It has been observed that low carbon ash does not activate the ketones towards similar stereoselectivity, clearly establishing that the high carbon ash has a definite role to play. The stereochemical outcome of the reductions has been rationalized on the basis of a probable transition state involving Lewis/Br⊘nsted acid sites present in the ash. Mesopores and macropores present in the ash are most likely to act as pockets for adsorption of ketones. Product analysis has been carried out using 1HNMR and 13CNMR. [ABSTRACT FROM PUBLISHER]

Abstract: This paper reports the p-nitrophenol (PNP) removal from aqueous solutions by adsorption onto active carbons (ACs). Nine ACs were prepared from acid-precipitated eucalyptus kraft lignin following a two-step process consisting in CO2 partial gasification (750–850°C) after carbonization (350–800°C) in N2 atmosphere. The amount adsorbed ranged from 1 to 4.4mmol/g, and it is related to the initial concentration of adsorbate, temperature, pH, burn off of the activated carbons, and contact time. The equilibrium results were fitted by the Temkin, Dubinin-Radushkevich, and Guggenheim-Anderson-de Boer equations. The main thermodynamic magnitudes were estimated as well, and their values indicated that the adsorption processes were spontaneous and exothermic. The kinetic study showed that the processes are of apparent second order related to the concentrations of the empty active sites on the ACs surface. The values of the effective diffusivities have been calculated and they have suggested that the internal diffusion controls the net mass transfer. The results obtained in the present work can be for the benefit of the preparation of new adsorbents, as well as the primary design of the adsorption equipment with separation or environmental purposes. [Copyright &y& Elsevier]

A fixed bed electrochemical reactor comprising stainless steel cathode/granular activated carbon (GAC) bed//Carbon anode//GAC bed//stainless steel cathode configuration was fabricated and tested for degradation of Reactive Blue 4 aqueous solutions (RB4). On the basis of measured concentrations of residual RB4 dye and total organic carbon (TOC), approximately 80–90% of RB4 dye was found to be degraded at 0.30–0.90A and 13.4±0.1V in 6 h under recirculation batch mode of operation (flow rate, 1.8Lh−1). The dye removal due to adsorption on carbon was ∼9–10% under the same experimental conditions but excluding applied current. The apparent Faradic efficiency and electrical energy consumption were estimated to be 2.8% and 16.0kWh kg−1 RB4 at the optimum current and voltage (0.6 A, 13.3 V). Further, the adsorption of the dye on GAC bed, cyclic voltammetric response of RB4, SEM and FT-IR characterization of original and spent carbon and ion chromatographic analysis of inorganic intermediates were carried out to elucidate the mechanism of dye degradation. It appears that the dye degradation takes place by ready scission of SO3H groups, and oxidation of mainframe chromophore (anthraquinone group). The chlorotriazine group resists to the electrooxidation and remains as the final reaction product. [Copyright &y& Elsevier]

Marine dissolved organic matter is a massive reservoir of carbon holding >200x the ocean biomass inventory. Primarily produced at the ocean surface and then exported to depth with overturn of the water column, this carbon can be sequestered in the ocean interior for centuries. Understanding the loss of dissolved organic carbon (DOC) upon export has been data limited, but recent global ocean surveys are overcoming that problem. Here we characterize three fractions of exported carbon by apparent continuity in removal rates: semi-labile and semi-refractory, summing to 20 PgC, and the balance as refractory DOC. Distinct lifetimes coupled with ocean circulation control where the fractions are exported to depth, and thus the carbon sequestration time scales. Maximum remineralization rates of exported DOC occur in the convergent subtropical gyres, where a range of ∼500 to <1500 mmol C m-2 yr-1 can exceed remineralization of sinking biogenic particles. Regions of high particle export production and highly stratified systems exhibit minimal exported DOC remineralization. [ABSTRACT FROM AUTHOR]

Recent studies reveal that reconstruction of close-packed metal surfaces induced by C6o adsorption is the rule rather than the exception. Two types of reconstruction are reported for C6o on different surfaces: (1) C6o sinks into a 7-atom hole, such as on Cu(111); and (2) C6o sits over a 1-atom hole, such as on Ag(111) and Pt( 111 ). An explanation for the preferred reconstruction type for different metals has been lacking. Here, we propose a criterion that predicts which reconstruction type should be expected: Namely, the formation of a 1 - or 7-atom hole is determined only by the substrate geometric structure, including the surface lattice constant and the interlayer spacing; remarkably, the reconstruction type appears not to depend on the substrate electronic structure. Our intuitive geometrical explanation is validated by comparative first-principles calculations of the energetics of CEO on Cu(111), Ru(0001), Pt(111), and Ag(111) surfaces, listed here with increasing surface lattice constant. This provides a uniform explanation for the different reconstruction types that are observed experimentally for C6o on different close-packed metal surfaces. Moreover, our results provide a better explanation for the decomposition behavior of C6o on Ru(0001). [ABSTRACT FROM AUTHOR]

Abstract: A typical curtain wall façade of an office building is modelled and studied in order to find the configuration of selected parameters that minimizes the total carbon emissions arising from building operation. Simulation based optimisation techniques, namely a PSO algorithm coupled to a dynamic energy simulation engine, are used to perform a fully automated search aimed at finding the optimal values of the envelope features. The application is significant since the energy efficiency and comfort conditions of highly glazed buildings strongly depend on envelope design. Results of the optimisation are presented and discussed for four different orientations of the façade, highlighting the potential savings in comparison to a standard façade construction. The performance of the algorithm in generating satisfactory results is examined, and a way to find additional near optimal solutions to provide diversity is suggested. Finally the impact of different types of external shading devices and different climates is also investigated. [Copyright &y& Elsevier]

Abstract: The possibility of fabricating a full graphene device was investigated by utilizing atomic layer etching (ALET) technology. By using O2 ALET which functions by oxygen radical adsorption followed by the removal of the oxygen chemisorbed on carbon, the removal of exactly one graphene layer per ALET cycle was detected through the increase of the transmittance by 2.3% after one ALET cycle and by the decrease of the G peak in the Raman spectra. The Raman spectra also showed an increase of the D peak after ALET, indicating the formation of physical damage on the graphene surface layer. This damage was mostly recovered by hydrogen annealing at 1000°C after ALET. Full graphene field effect transistors (source, drain: 3 layer, channel: 1, 2, 3 layer) were fabricated by reducing the channel layers using ALET, followed by annealing, and the electrical characteristics of the devices showed the possibility of fabricating fully functional graphene devices composed of an all graphene source/drain and graphene channel by utilizing ALET. [Copyright &y& Elsevier]

Abstract: To develop cost-effective carbon-based sorbents used in gas-phase elemental mercury removal, the performance of commercial bamboo charcoal (BC) produced from renewable bioresource of bamboo and modified BC was investigated with a bench-scale fixed-bed reactor. The simple impregnation method was used to modify the BC using ZnCl2, NH3·H2O and HNO3 separately. BET, XPS, elemental analysis and FT-IR were used to determine the pore structure and surface chemistry of the sorbents. The characterization of the physical and chemical properties of sorbents in relation to Hg0 adsorption capacity provided important information on the Hg0 adsorption mechanism. This suggested that the modified BCs have excellent adsorption potential for elemental mercury at a relatively higher temperature of 140°C except for the NH3·H2O impregnated BC. The amount of Hg0 absorbed depends on the concentration of impregnant used. The impregnation has increased the sorbents’ active sites for mercury adsorption and the specific reaction mechanism has been further analyzed. [Copyright &y& Elsevier]

Wastewater containing pentachlorophenol (PCP) was treated by granular activated carbon (GAC) adsorption and double-dielectric barrier discharge (D-DBD) plasma. A packed bed D-DBD reactor was applied for removal of PCP on GAC and GAC regeneration, where the discharge gap was filled with GAC. PCP degradation efficiency of 65% and GAC regeneration efficiency (RE) of 87% were achieved. Effects of discharge power, treatment time and O flow rate on PCP degradation and GAC regeneration were investigated. Increasing discharge power, treatment time and O flow rate were favorable for PCP degradation, and also contributed to GAC RE. C-Cl bonds in PCP were cleaved by D-DBD plasma. Effect of D-DBD plasma on physical and chemical properties of GAC during GAC regeneration process was characterized by N adsorption and Boehm titration. This study is expected to demonstrate the feasibility of applying D-DBD plasma for efficient organic wastewater treatment by coupling with GAC adsorption. [ABSTRACT FROM AUTHOR]