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Sample records for activated carbon charcoal

  1. Charcoal and activated carbon at elevated pressure

    SciTech Connect

    Antal, M.J. Jr.; Dai, Xiangfeng; Norberg, N.

    1995-12-01

    High quality charcoal has been produced with very high yields of 50% to 60% from macadamia nut and kukui nut shells and of 44% to 47% from Eucalyptus and Leucaena wood in a bench scale unit at elevated pressure on a 2 to 3 hour cycle, compared to commercial practice of 25% to 30% yield on a 7 to 12 day operating cycle. Neither air pollution nor tar is produced by the process. The effects of feedstock pretreatments with metal additives on charcoal yield are evaluated in this paper. Also, the influences of steam and air partial pressure and total pressure on yields of activated carbon from high yield charcoal are presented.

  2. Activated coconut shell charcoal carbon using chemical-physical activation

    NASA Astrophysics Data System (ADS)

    Budi, Esmar; Umiatin, Nasbey, Hadi; Bintoro, Ridho Akbar; Wulandari, Futri; Erlina

    2016-02-01

    The use of activated carbon from natural material such as coconut shell charcoal as metal absorbance of the wastewater is a new trend. The activation of coconut shell charcoal carbon by using chemical-physical activation has been investigated. Coconut shell was pyrolized in kiln at temperature about 75 - 150 °C for about 6 hours in producing charcoal. The charcoal as the sample was shieved into milimeter sized granule particle and chemically activated by immersing in various concentration of HCl, H3PO4, KOH and NaOH solutions. The samples then was physically activated using horizontal furnace at 400°C for 1 hours in argon gas environment with flow rate of 200 kg/m3. The surface morphology and carbon content of activated carbon were characterized by using SEM/EDS. The result shows that the pores of activated carbon are openned wider as the chemical activator concentration is increased due to an excessive chemical attack. However, the pores tend to be closed as further increasing in chemical activator concentration due to carbon collapsing.

  3. Production of charcoal and activated carbon at elevated pressure

    SciTech Connect

    Dai, Xiangfeng; Norberg, N.; Antal, M.J. Jr.

    1995-12-31

    With its wide range of properties, charcoal finds many commercial applications for domestic cooking, refining of metals (steel, copper, bronze, nickel, aluminum and electro-manganese), production of chemicals (carbon disulfide, calcium carbide, silicon carbide, sodium cyanide, carbon black, fireworks, gaseous chemicals, absorbents, soil conditioners and pharmaceuticals), as well as production of activated carbon and synthesis gas. In 1991, the world production of charcoal was 22.8 million cubic meters (3.8 million metric tons) as shown in Table 1. Brazil is the world`s largest charcoal producer --- 5.9 million cubic meters or one million metric tons was produced in 1991, most of which is used in steel and iron industry. African countries produced 45% of the world total amount of charcoal, where 86% of the wood-based energy is for domestic use, most of which is inefficiently used. Charcoal is produced commercially in kilns with a 25% to 30% yield by mass on a 7 to 12 day operating cycle. Until recently, the highest yield of good quality charcoal reported in the literature was 38%. In this paper, and ASME code rated experimental system is presented for producing charcoal and activated carbon from biomass.

  4. Pore structure of the activated coconut shell charcoal carbon

    NASA Astrophysics Data System (ADS)

    Budi, E.; Nasbey, H.; Yuniarti, B. D. P.; Nurmayatri, Y.; Fahdiana, J.; Budi, A. S.

    2014-09-01

    The development of activated carbon from coconut shell charcoal has been investigated by using physical method to determine the influence of activation parameters in term of temperature, argon gas pressure and time period on the pore structure of the activated carbon. The coconut shell charcoal was produced by pyrolisis process at temperature of about 75 - 150 °C for 6 hours. The charcoal was activated at various temperature (532, 700 and 868 °C), argon gas pressure (6.59, 15 and 23.4 kgf/cm2) and time period of (10, 60 and 120 minutes). The results showed that the pores size were reduced and distributed uniformly as the activation parameters are increased.

  5. Activated Charcoal

    MedlinePlus

    ... is used to treat poisonings, reduce intestinal gas (flatulence), lower cholesterol levels, prevent hangover, and treat bile ... lower cholesterol levels in the blood. Decreasing gas (flatulence). Some studies show that activated charcoal is effective ...

  6. Synthesis of a high-yield activated carbon by air gasification of macadamia nut shell charcoal

    SciTech Connect

    Dai, X.; Antal, M.J. Jr.

    1999-09-01

    Macadamia nut shell charcoal was heated in an inert environment to temperatures above 1000 K (carbonized), reacted with oxygen (Po{sub 2} = 2.68--11.3 kPa) at temperatures between 525 and 586 K (oxygenated), and heated again in an inert environment to temperatures above 1000 K (activated) to produce an activated carbon. Carbons produced by this process possess surface areas and iodine numbers in the range of 400--550. Overall yields of these carbons (based on the dry, raw macadamia nut shell feed) ranged from 24 to 30 wt %. Under the conditions employed in this work, the rates of chemisorption and gasification were not mass transfer limited. Initially, the gasification reaction was first-order with respect to oxygen concentration but became independent of oxygen concentration as the surface sites of the carbon became saturated with oxygen.

  7. Passivation of fluorinated activated charcoal

    SciTech Connect

    Del Cul, G.D.; Trowbridge, L.D.; Simmons, D.W.; Williams, D.F.; Toth, L.M.

    1997-10-01

    The Molten Salt Reactor Experiment (MSRE), at the Oak Ridge National Laboratory has been shut down since 1969 when the fuel salt was drained from the core into two Hastelloy N tanks at the reactor site. In 1995, a multiyear project was launched to remediate the potentially hazardous conditions generated by the movement of fissile material and reactive gases from the storage tanks into the piping system and an auxiliary charcoal bed (ACB). The top 12 in. of the ACB is known by gamma scan and thermal analysis to contain about 2.6 kg U-233. According to the laboratory tests, a few feet of fluorinated charcoal are believed to extend beyond the uranium front. The remainder of the ACB should consist of unreacted charcoal. Fluorinated charcoal, when subjected to rapid heating, can decompose generating gaseous products. Under confined conditions, the sudden exothermic decomposition can produce high temperatures and pressures of near-explosive characteristics. Since it will be necessary to drill and tap the ACB to allow installation of piping and instrumentation for remediation and recovery activities, it is necessary to chemically convert the reactive fluorinated charcoal into a more stable material. Ammonia can be administered to the ACB as a volatile denaturing agent that results in the conversion of the C{sub x}F to carbon and ammonium fluoride, NH{sub 4}F. The charcoal laden with NH{sub 4}F can then be heated without risking any sudden decomposition. The only consequence of heating the treated material will be the volatilization of NH{sub 4}F as a mixture of NH{sub 3} and HF, which would primarily recombine as NH{sub 4}F on surfaces below 200 C. The planned scheme for the ACB denaturing is to flow diluted ammonia gas in steps of increasing NH{sub 3} concentration, 2% to 50%, followed by the injection of pure ammonia. This report summarizes the planned passivation treatment scheme to stabilize the ACB and remove the potential hazards. It also includes basic information

  8. [Biochemical effects of chronic peroral administration of carbon nanotubes and activated charcoal in drinking water in rats].

    PubMed

    Khripach, L V; Rakhmanin, Iu A; Mikhajlova, R I; Knyazeva, T D; Koganova, Z I; Zhelezniak, E V; Savostikova, O N; Alekseeva, A V; Kameneckaya, D V; Ryzhova, I N; Kruglova, E V; Revazova, T L

    2014-01-01

    Chronic 6-month experiment was carried out in rats, which received drinking water with multi-walled carbon nanotubes (MWCNTs), diameter of 15-40 nm, length ≥ 2 mkm) or activated charcoal (AC, diameter of 10-100 mkm), blood samples of the animals were used for assessment of biochemical markers. Both coal compounds induced the appearance of signs of oxidative stress 2 weeks after the beginning of the experiment and alteration of serum markers of liver and renal damage, as well as changes of cortisol and protein serum concentrations later Thus, despite of known high (asbest-like) inhalation toxicity of carbon nanotubes in comparison with other carbon allotrops (fullerenes and black carbon), we have found similar effects of MWCNTs and carbon microparticles in orally treated rats.

  9. Charcoal bed operation for optimal organic carbon removal

    SciTech Connect

    Merritt, C.M.; Scala, F.R.

    1995-05-01

    Historically, evaporation, reverse osmosis or charcoal-demineralizer systems have been used to remove impurities in liquid radwaste processing systems. At Nine Mile point, we recently replaced our evaporators with charcoal-demineralizer systems to purify floor drain water. A comparison of the evaporator to the charcoal-demineralizer system has shown that the charcoal-demineralizer system is more effective in organic carbon removal. We also show the performance data of the Granulated Activated Charcoal (GAC) vessel as a mechanical filter. Actual data showing that frequent backflushing and controlled flow rates through the GAC vessel dramatically increases Total Organic Carbon (TOC) removal efficiency. GAC vessel dramatically increases Total Organic Carbon (TOC) removal efficiency. Recommendations are provided for operating the GAC vessel to ensure optimal performance.

  10. Effects of Carbonization Parameters of Moso-Bamboo-Based Porous Charcoal on Capturing Carbon Dioxide

    PubMed Central

    Jhan, Jhih-Wei; Cheng, Yi-Ming; Cheng, Hau-Hsein

    2014-01-01

    This study experimentally analyzed the carbon dioxide adsorption capacity of Moso-bamboo- (Phyllostachys edulis-) based porous charcoal. The porous charcoal was prepared at various carbonization temperatures and ground into powders with 60, 100, and 170 meshes, respectively. In order to understand the adsorption characteristics of porous charcoal, its fundamental properties, namely, charcoal yield, ash content, pH value, Brunauer-Emmett-Teller (BET) surface area, iodine number, pore volume, and powder size, were analyzed. The results show that when the carbonization temperature was increased, the charcoal yield decreased and the pH value increased. Moreover, the bamboo carbonized at a temperature of 1000°C for 2 h had the highest iodine sorption value and BET surface area. In the experiments, charcoal powders prepared at various carbonization temperatures were used to adsorb 1.854% CO2 for 120 h. The results show that the bamboo charcoal carbonized at 1000°C and ground with a 170 mesh had the best adsorption capacity, significantly decreasing the CO2 concentration to 0.836%. At room temperature and atmospheric pressure, the Moso-bamboo-based porous charcoal exhibited much better CO2 adsorption capacity compared to that of commercially available 350-mesh activated carbon. PMID:25225639

  11. Effects of carbonization parameters of Moso-bamboo-based porous charcoal on capturing carbon dioxide.

    PubMed

    Huang, Pei-Hsing; Jhan, Jhih-Wei; Cheng, Yi-Ming; Cheng, Hau-Hsein

    2014-01-01

    This study experimentally analyzed the carbon dioxide adsorption capacity of Moso-bamboo- (Phyllostachys edulis-) based porous charcoal. The porous charcoal was prepared at various carbonization temperatures and ground into powders with 60, 100, and 170 meshes, respectively. In order to understand the adsorption characteristics of porous charcoal, its fundamental properties, namely, charcoal yield, ash content, pH value, Brunauer-Emmett-Teller (BET) surface area, iodine number, pore volume, and powder size, were analyzed. The results show that when the carbonization temperature was increased, the charcoal yield decreased and the pH value increased. Moreover, the bamboo carbonized at a temperature of 1000(°)C for 2 h had the highest iodine sorption value and BET surface area. In the experiments, charcoal powders prepared at various carbonization temperatures were used to adsorb 1.854% CO2 for 120 h. The results show that the bamboo charcoal carbonized at 1000(°)C and ground with a 170 mesh had the best adsorpt on capacity, significantly decreasing the CO2 concentration to 0.836%. At room temperature and atmospheric pressure, the Moso-bamboo-based porous charcoal exhibited much better CO2 adsorption capacity compared to that of commercially available 350-mesh activated carbon.

  12. A Novel Activated-Charcoal-Doped Multiwalled Carbon Nanotube Hybrid for Quasi-Solid-State Dye-Sensitized Solar Cell Outperforming Pt Electrode.

    PubMed

    Arbab, Alvira Ayoub; Sun, Kyung Chul; Sahito, Iftikhar Ali; Qadir, Muhammad Bilal; Choi, Yun Seon; Jeong, Sung Hoon

    2016-03-23

    Highly conductive mesoporous carbon structures based on multiwalled carbon nanotubes (MWCNTs) and activated charcoal (AC) were synthesized by an enzymatic dispersion method. The synthesized carbon configuration consists of synchronized structures of highly conductive MWCNT and porous activated charcoal morphology. The proposed carbon structure was used as counter electrode (CE) for quasi-solid-state dye-sensitized solar cells (DSSCs). The AC-doped MWCNT hybrid showed much enhanced electrocatalytic activity (ECA) toward polymer gel electrolyte and revealed a charge transfer resistance (RCT) of 0.60 Ω, demonstrating a fast electron transport mechanism. The exceptional electrocatalytic activity and high conductivity of the AC-doped MWCNT hybrid CE are associated with its synchronized features of high surface area and electronic conductivity, which produces higher interfacial reaction with the quasi-solid electrolyte. Morphological studies confirm the forms of amorphous and conductive 3D carbon structure with high density of CNT colloid. The excessive oxygen surface groups and defect-rich structure can entrap an excessive volume of quasi-solid electrolyte and locate multiple sites for iodide/triiodide catalytic reaction. The resultant D719 DSSC composed of this novel hybrid CE fabricated with polymer gel electrolyte demonstrated an efficiency of 10.05% with a high fill factor (83%), outperforming the Pt electrode. Such facile synthesis of CE together with low cost and sustainability supports the proposed DSSCs' structure to stand out as an efficient next-generation photovoltaic device.

  13. Antidotal effectiveness of activated charcoal in rats

    SciTech Connect

    Curd-Sneed, C.D.

    1986-01-01

    This study was designed to investigate the relative adsorption of radiolabeled /sup 14/C-sodium pentobarbital by three types of activated charcoal. Factors affection adsorption of the drug by SuperChar, United States Pharmacopeia (USP), and Darco G-60 activated charcoals with surface areas of 2800-3500 m2/g, 1000 m/sup 2//g, and 650 m/sup 2//g, respectively, were studied both in vitro and in vivo. For in vitro experiments, the drug was dissolved in water of 70% sorbitol (w/v), and the maximum binding capacity and dissociation constants for each of the charcoals were calculated. Rank order of maximum binding capacity was directly proportional to charcoal surface area in both water and sorbitol, while the dissociation constants for the charcoals in water were not different. For in vivo experiments, absorption of orally administered sodium pentobarbital (40 mg/kg) was studied in rats with and without activated charcoal administration. The results of this research suggest that: (1) SuperChar given in water possesses the greatest antidotal efficacy, (2) sorbitol induced catharsis does not reduce oral absorption of sodium pentobarbital, and (3) sorbitol enhances the antidotal efficacy of USP charcoal.

  14. Some theoretical priciples of the activation of wood charcoal by steam

    SciTech Connect

    Fedoseev, A.S.

    1982-01-01

    Kinetics and diffusion in the pores of a carbonaceous material are considered. The macroscopic rate of the reaction of steam with the carbon of wood charcoal has been determined. The optimum conditions for the activation of wood charcoal have been found.

  15. In vitro adsorption of tilidine HCl by activated charcoal.

    PubMed

    Cordonnier, J A; Van den Heede, M A; Heyndrickx, A M

    In vitro studies were carried out in order to determine the adsorption of tilidine HCl, a narcotic analgesic, by activated charcoal (max. adsorption capacity 185.5 mg/g of charcoal). The path of the adsorption isotherms at pH 1.2 and 7.5 suggests that the in vivo adsorption of tilidine HCl may be increased when the drug passes from the stomach to the intestine, unless the intestinal content exerts a displacing effect. Nevertheless, the adsorption was dependent on the quantity of activated charcoal used, becoming more complete when the quantity of activated charcoal was increased. The effects of additives on the adsorption capacity of activated charcoal were also investigated in vitro. Ethanol, sorbitol and sucrose significantly reduced drug adsorption, while cacao powder, milk and starch had no effect on tilidine adsorption. At an acid pH, Federa Activated Charcoal significantly adsorbed more drug than either Norit A or Activated Charcoal Merck.

  16. Effect of activated charcoal on the pharmacokinetics of pholcodine, with special reference to delayed charcoal ingestion.

    PubMed

    Laine, K; Kivistö, K T; Ojala-Karlsson, P; Neuvonen, P J

    1997-02-01

    We conducted a randomized study with four parallel groups to investigate the effect of single and multiple doses of activated charcoal on the absorption and elimination of pholcodine administered in a cough syrup. The first group received 100 mg of pholcodine on an empty stomach with water only (control); the second group took 25 g of activated charcoal immediately after pholcodine; the third group received 25 g of activated charcoal 2 h and the fourth group 5 h after ingestion of the 100-mg dose of pholcodine. In addition, the fourth group received multiple doses (10 g each) of charcoal every 12 h for 84 h. Blood samples were collected for 96 h and urine for 72 h. Pholcodine concentrations were measured by high-performance liquid chromatography. A significant reduction in absorption was found when charcoal was administered immediately after pholcodine; the AUC0-96h was reduced by 91% (p < 0.0005), the Cmax by 77% (p < 0.0005), and the amount of pholcodine excreted into urine by 85% (p < 0.0005). When charcoal was administered 2 h after pholcodine, the AUC0-96h was reduced by 26% (p = 0.002), the Cmax by 23% (p = NS), and the urinary excretion by 28% (p = 0.004). When administered 5 h after pholcodine, charcoal produced only a 17% reduction in the AUC0-96h (p = 0.06), but reduced the further absorption of pholcodine still present in the gastrointestinal tract at the time of charcoal administration, as measured by AUC5-96h (p = 0.006). Repeated administration of charcoal failed to accelerate the elimination of pholcodine. We conclude that activated charcoal is effective in preventing the absorption of pholcodine, and its administration can be beneficial even several hours after pholcodine ingestion.

  17. Le Carbone, a charcoal supplement, modulates DSS-induced acute colitis in mice through activation of AMPKα and downregulation of STAT3 and caspase 3 dependent apoptotic pathways.

    PubMed

    Afrin, Mst Rejina; Arumugam, Somasundaram; Rahman, Md Azizur; Karuppagounder, Vengadeshprabhu; Sreedhar, Remya; Harima, Meilei; Suzuki, Hiroshi; Nakamura, Takashi; Miyashita, Shizuka; Suzuki, Kenji; Ueno, Kazuyuki; Watanabe, Kenichi

    2017-02-01

    Le Carbone (LC) is a charcoal supplement, which contains a large amount of dietary fibers. Several studies suggested that charcoal supplement may be beneficial for stomach disorders, diarrhea, gas and indigestion. But no studies address whether LC intake would suppress inflammation, cell proliferation or disease progression in colitis. In the present study, the effect of LC on experimental colitis induced by dextran sulfate sodium (DSS) in mice and its possible mechanism of action were examined. A study was designed for 8days, using C57BL/6 female mice that were administered with 3% DSS in drinking water for 7days followed by another 1day consumption of normal water with or without treatment. LC suspension was administered daily for 7days via oral gavage using 5mg/mouse in treatment group and normal group was supplied with drinking water. LC suspension significantly attenuated the loss of body weight and shortening of colon length induced by DSS. The disease activity index, histopathologic changes were significantly reduced by LC treatment. The inflammatory mediators TNFα, IL-1β, p-STAT3 and p-NF-κB induced in the colon by DSS were markedly suppressed by LC. The increased activation of AMPKα in the colon was also detected in LC group. Furthermore, the apoptotic marker protein cleaved caspase 3 was down-regulated and anti-apoptotic proteins Bcl2 and Bcl-xL were significantly up-regulated by LC treatment. Taken together, our results demonstrate the ability of LC to inhibit inflammation, apoptosis and give some evidence for its potential use as adjuvant treatment of inflammatory bowel disease.

  18. Charcoal versus LPG grilling: A carbon-footprint comparison

    SciTech Connect

    Johnson, Eric

    2009-11-15

    Undoubtedly, grilling is popular. Britons fire up their barbeques some 60 million times a year, consuming many thousands of tonnes of fuel. In milder climates consumption is even higher, and in the developing world, charcoal continues to be an essential cooking fuel. So it is worth comparing the carbon footprints of the two major grill types, charcoal and LPG, and that was the purpose of the study this paper documents. Charcoal and LPG grill systems were defined, and their carbon footprints were calculated for a base case and for some plausible variations to that base case. In the base case, the charcoal grilling footprint of 998 kg CO{sub 2}e is almost three times as large as that for LPG grilling, 349 kg CO{sub 2}e. The relationship is robust under all plausible sensitivities. The overwhelming factors are that as a fuel, LPG is dramatically more efficient than charcoal in its production and considerably more efficient in cooking. Secondary factors are: use of firelighters, which LPG does not need; LPG's use of a heavier, more complicated grill; and LPG's use of cylinders that charcoal does not need.

  19. Cr(VI) removal from synthetic wastewater using coconut shell charcoal and commercial activated carbon modified with oxidizing agents and/or chitosan.

    PubMed

    Babel, Sandhya; Kurniawan, Tonni Agustiono

    2004-02-01

    In this study, the technical feasibility of coconut shell charcoal (CSC) and commercial activated carbon (CAC) for Cr(VI) removal is investigated in batch studies using synthetic electroplating wastewater. Both granular adsorbents are made up of coconut shell (Cocos nucifera L.), an agricultural waste from local coconut industries. Surface modifications of CSC and CAC with chitosan and/or oxidizing agents, such as sulfuric acid and nitric acid, respectively, are also conducted to improve removal performance. The results of their Cr removal performances are statistically compared. It is evident that adsorbents chemically modified with an oxidizing agent demonstrate better Cr(VI) removal capabilities than as-received adsorbents in terms of adsorption rate. Both CSC and CAC, which have been oxidized with nitric acid, have higher Cr adsorption capacities (CSC: 10.88, CAC: 15.47 mg g(-1)) than those oxidized with sulfuric acid (CSC: 4.05, CAC: 8.94 mg g(-1)) and non-treated CSC coated with chitosan (CSCCC: 3.65 mg g(-1)), respectively, suggesting that surface modification of a carbon adsorbent with a strong oxidizing agent generates more adsorption sites on their solid surface for metal adsorption.

  20. Preparation of highly developed mesoporous activated carbon fiber from liquefied wood using wood charcoal as additive and its adsorption of methylene blue from solution.

    PubMed

    Ma, Xiaojun; Zhang, Fan; Zhu, Junyan; Yu, Lili; Liu, Xinyan

    2014-07-01

    Activated carbon fiber (C-WACF) with super high surface area and well-developed small mesopores were prepared by liquefied wood and uses wood charcoal (WC) as additive. The characterization and properties of C-WACF were investigated by XRD, XPS and N2 adsorption. Results showed the pore development was significant at temperatures >750°C, and reached a maximum BET surface area (2604.7 m(2)/g) and total pore volume (1.433 cm(3)/g) at 850°C, of which 86.8% was from the contribution of the small mesopores of 2-4 nm. It was also found that the mesopore volume and methylene blue adsorption of C-WACF were highly increased as the temperature increases from 750 to 850°C. Additionally, the reduction of graphitic layers, the obvious changes of functional groups and the more unstable carbons on the surface of C-WACF, which played important roles in the formation of mesopores, were also observed.

  1. Effect of Charcoal Volatile Matter Content and Feedstock on Soil Microbe-Carbon-Nitrogen Dynamics

    NASA Astrophysics Data System (ADS)

    McClellan, T.; Deenik, J. L.; Hockaday, W. C.; Campbell, S.; Antal, M. J., Jr.

    2010-12-01

    Charcoal has important biogeochemical implications in soil—first as a means to sequester carbon, and second as a soil conditioner to potentially enhance soil quality and fertility. Volatile matter (VM) content is a property of charcoal which describes its degree of thermal alteration, or carbonization. Results from greenhouse experiments have shown that plant growth can be negatively affected by charcoals with high VM content (20-35%), with and without fertilizer supplements, whereas low VM charcoal (6-9%) increased plant growth when combined with fertilizer. We conducted two laboratory studies to characterize the VM content of charcoals derived from two feedstocks (corncob and kiawe) and relate observed differences to key aspects of soil fertility. Using Fourier transform infrared spectroscopy (FTIR), 13C nuclear magnetic resonance (NMR), total phenol content (using a Prussian blue colorimetric assay), and gas chromatography-mass spectrometry (GC-MS), we found that the VM content of charcoal primarily consisted of alkanes, oxygen-substituted alkanes, and phenolic compounds. However, the GC-MS data indicated that charcoals can differ vastly in their extractable fraction, depending upon both VM content and feedstock. In a second set of experiments, we examined the effect of VM content and feedstock on soil microbial activity, available nitrogen (N), and soluble carbon (C). High VM corncob charcoals significantly enhanced microbial activity, coupled with net reduction in available N and soluble C. For a given feedstock, the extent of this effect was dependent upon VM content. However, the overall effect of VM content on microbial dynamics was apparently related to the composition of the acetone-extractable fraction, which was particularly important when comparing two charcoals derived from different feedstocks but with the equivalent VM contents. Removing the acetone-extractable fraction from the 23% VM corncob charcoal significantly reduced the enhancement of

  2. Variability of mitomycin C adsorption by activated charcoal.

    PubMed

    Shah, I A; Lindup, W E; McCulloch, P G

    1998-03-01

    A saline suspension of mitomycin C adsorbed on activated charcoal and administered intraperitoneally has been reported to be safe and effective in the treatment of gastric carcinoma. Activated charcoal specifically targets tumour and lymph-node tissues and the sustained higher local drug concentration is thought to be beneficial. The charcoal particles used in these suspensions have varied in size from > 147 microm to < 20 nm in diameter, but no data have been published to show how this might affect drug adsorption and delivery. Any variability in drug adsorption could pose a serious clinical risk for drugs with a narrow therapeutic index. We have, therefore, investigated the adsorption of mitomycin C on activated charcoal in-vitro. Activated charcoal was ground and sieved to yield four size-fractions between 180 and 53 microm. Adsorption isotherms (n > or = 3) were constructed and applied to the Freundlich model with 0-l00 microg mL(-1) mitomycin C measured by HPLC with detection at 365 nm. Adsorption of mitomycin C by activated charcoal varied by a factor of three under identical conditions at room temperature (21 degrees C) and at 37 degrees C. The specific adsorption (microg mitomycin C (mg activated charcoal)(-1)) was generally higher at 37 degrees C than at room temperature. The variability of mitomycin C adsorption was greatly reduced by addition of the surface-active agent polyvinylpyrollidone, used to determine that adsorption of mitomycin C was independent of activated charcoal particle size. The characteristics of adsorption of mitomycin C by activated charcoal are complex and should be thoroughly investigated to discover the critical controlling factors before submitting the suspensions for further clinical evaluation.

  3. Activated charcoal for acute overdose: a reappraisal.

    PubMed

    Juurlink, David N

    2016-03-01

    Sometimes mistakenly characterized as a 'universal antidote,' activated charcoal (AC) is the most frequently employed method of gastrointestinal decontamination in the developed world. Typically administered as a single dose (SDAC), its tremendous surface area permits the binding of many drugs and toxins in the gastrointestinal lumen, reducing their systemic absorption. Like other decontamination procedures, the utility of SDAC attenuates with time, and, although generally safe, it is not free of risk. A large body of evidence demonstrates that SDAC can reduce the absorption of drugs and xenobiotics but most such studies involve volunteers and have little generalizability to clinical practice. Few rigorous clinical trials of SDAC have been conducted, and none validate or refute its utility in those patients who are intuitively most likely to benefit. Over the past decade, a growing body of observational data have demonstrated that SDAC can elicit substantial reductions in drug absorption in acutely poisoned patients. The challenge for clinicians rests in differentiating those patients most likely to benefit from SDAC from those in whom meaningful improvement is doubtful. This is often a difficult determination not well suited to an algorithmic approach. The present narrative review summarizes the data supporting the benefits and harms of SDAC, and offers pragmatic suggestions for clinical practice.

  4. Towards an improvement of carbon accounting for wildfires: incorporation of charcoal production into carbon emission models

    NASA Astrophysics Data System (ADS)

    Doerr, Stefan H.; Santin, Cristina; de Groot, Bill

    2015-04-01

    Every year fires release to the atmosphere the equivalent to 20-30% of the carbon (C) emissions from fossil fuel consumption, with future emissions from wildfires expected to increase under a warming climate. Critically, however, part of the biomass C affected by fire is not emitted during burning, but converted into charcoal, which is very resistant to environmental degradation and, thus, contributes to long-term C sequestration. The magnitude of charcoal production from wildfires as a long-term C sink remains essentially unknown and, to the date, charcoal production has not been included in wildfire emission and C budget models. Here we present complete inventories of charcoal production in two fuel-rich, but otherwise very different ecosystems: i) a boreal conifer forest (experimental stand-replacing crown fire; Canada, 2012) and a dry eucalyptus forest (high-intensity fuel reduction burn; Australia 2014). Our data show that, when considering all the fuel components and quantifying all the charcoal produced from each (i.e. bark, dead wood debris, fine fuels), the overall amount of charcoal produced is significant: up to a third of the biomass C affected by fire. These findings indicate that charcoal production from wildfires could represent a major and currently unaccounted error in the estimation of the effects of wildfires in the global C balance. We suggest an initial approach to include charcoal production in C emission models, by using our case study of a boreal forest fire and the Canadian Fire Effects Model (CanFIRE). We also provide recommendations of how a 'conversion factor' for charcoal production could be relatively easily estimated when emission factors for different types of fuels and fire conditions are experimentally obtained. Ultimately, this presentation is a call for integrative collaboration between the fire emission modelling community and the charcoal community to work together towards the improvement of C accounting for wildfires.

  5. Application of activated charcoal radon collectors in high humidity environments.

    PubMed

    Iimoto, Takeshi; Tokonami, Shinji; Morishita, Yasuaki; Kosako, Toshiso

    2005-01-01

    Most commercially based activated charcoal radon collectors were designed for use in indoor environments. However, at present, they are often used for research in radon surveys in unique environments, such as in the bathrooms, underground areas, mines, caves and tunnels. In these environments, the relative humidity would be around 100%, and a change in the sensitivity of cpm(Bq m(-3))(-1)(radon) would occur. For this study, the reduction in the sensitivity of activated charcoal radon collector due to environmental humidity was investigated, and the data correction was discussed. Here, ST-100 (Pico-Rad) was selected as an example of a familiar activated charcoal radon collector. According to our performance test, the humidity of 90% (20 degrees C) resulted in a 15% reduction of the sensitivity for 24 h collection. The ST-100 user should discuss the necessity of data correction by comparing the change of sensitivity with other levels of estimation errors.

  6. The role of activated charcoal in plant tissue culture.

    PubMed

    Thomas, T Dennis

    2008-01-01

    Activated charcoal has a very fine network of pores with large inner surface area on which many substances can be adsorbed. Activated charcoal is often used in tissue culture to improve cell growth and development. It plays a critical role in micropropagation, orchid seed germination, somatic embryogenesis, anther culture, synthetic seed production, protoplast culture, rooting, stem elongation, bulb formation etc. The promotary effects of AC on morphogenesis may be mainly due to its irreversible adsorption of inhibitory compounds in the culture medium and substancially decreasing the toxic metabolites, phenolic exudation and brown exudate accumulation. In addition to this activated charcoal is involved in a number of stimulatory and inhibitory activities including the release of substances naturally present in AC which promote growth, alteration and darkening of culture media, and adsorption of vitamins, metal ions and plant growth regulators, including abscisic acid and gaseous ethylene. The effect of AC on growth regulator uptake is still unclear but some workers believe that AC may gradually release certain adsorbed products, such as nutrients and growth regulators which become available to plants. This review focuses on the various roles of activated charcoal in plant tissue culture and the recent developments in this area.

  7. Activated charcoal. (Latest citations from the Compendex database). Published Search

    SciTech Connect

    Not Available

    1993-06-01

    The bibliography contains citations concerning theoretical aspects and industrial applications of activated charcoal. Topics include adsorption capacity and mechanism studies, kinetic and thermodynamic aspects, and description and evaluation of adsorptive abilities. Applications include use in water analyses and waste treatment, air pollution control and measurement, and in nuclear facilities. (Contains a minimum of 151 citations and includes a subject term index and title list.)

  8. Carbon Sequestration and Fertility after Centennial Time Scale Incorporation of Charcoal into Soil

    PubMed Central

    Criscuoli, Irene; Alberti, Giorgio; Baronti, Silvia; Favilli, Filippo; Martinez, Cristina; Calzolari, Costanza; Pusceddu, Emanuela; Rumpel, Cornelia; Viola, Roberto; Miglietta, Franco

    2014-01-01

    The addition of pyrogenic carbon (C) in the soil is considered a potential strategy to achieve direct C sequestration and potential reduction of non-CO2 greenhouse gas emissions. In this paper, we investigated the long term effects of charcoal addition on C sequestration and soil physico-chemical properties by studying a series of abandoned charcoal hearths in the Eastern Alps of Italy established in the XIX century. This natural setting can be seen as an analogue of a deliberate experiment with replications. Carbon sequestration was assessed indirectly by comparing the amount of pyrogenic C present in the hearths (23.3±4.7 kg C m−2) with the estimated amount of charcoal that was left on the soil after the carbonization (29.3±5.1 kg C m−2). After taking into account uncertainty associated with parameters’ estimation, we were able to conclude that 80±21% of the C originally added to the soil via charcoal can still be found there and that charcoal has an overall Mean Residence Time of 650±139 years, thus supporting the view that charcoal incorporation is an effective way to sequester atmospheric CO2. We also observed an overall change in the physical properties (hydrophobicity and bulk density) of charcoal hearth soils and an accumulation of nutrients compared to the adjacent soil without charcoal. We caution, however, that our site-specific results should not be generalized without further study. PMID:24614647

  9. Carbon sequestration and fertility after centennial time scale incorporation of charcoal into soil.

    PubMed

    Criscuoli, Irene; Alberti, Giorgio; Baronti, Silvia; Favilli, Filippo; Martinez, Cristina; Calzolari, Costanza; Pusceddu, Emanuela; Rumpel, Cornelia; Viola, Roberto; Miglietta, Franco

    2014-01-01

    The addition of pyrogenic carbon (C) in the soil is considered a potential strategy to achieve direct C sequestration and potential reduction of non-CO2 greenhouse gas emissions. In this paper, we investigated the long term effects of charcoal addition on C sequestration and soil physico-chemical properties by studying a series of abandoned charcoal hearths in the Eastern Alps of Italy established in the XIX century. This natural setting can be seen as an analogue of a deliberate experiment with replications. Carbon sequestration was assessed indirectly by comparing the amount of pyrogenic C present in the hearths (23.3±4.7 kg C m(-2)) with the estimated amount of charcoal that was left on the soil after the carbonization (29.3±5.1 kg C m(-2)). After taking into account uncertainty associated with parameters' estimation, we were able to conclude that 80±21% of the C originally added to the soil via charcoal can still be found there and that charcoal has an overall Mean Residence Time of 650±139 years, thus supporting the view that charcoal incorporation is an effective way to sequester atmospheric CO2. We also observed an overall change in the physical properties (hydrophobicity and bulk density) of charcoal hearth soils and an accumulation of nutrients compared to the adjacent soil without charcoal. We caution, however, that our site-specific results should not be generalized without further study.

  10. Charcoal addition to soils in NE England: a carbon sink with environmental co-benefits?

    PubMed

    Bell, M J; Worrall, F

    2011-04-01

    Interest in the application of biochar (charcoal produced during the pyrolysis of biomass) to agricultural land is increasing across the world, recognised as a potential way to capture and store atmospheric carbon. Its interest is heightened by its potential co-benefits for soil quality and fertility. The majority of research has however been undertaken in tropical rather than temperate regions. This study assessed the potential for lump-wood charcoal addition (as a substitute for biochar) to soil types which are typically under arable and forest land-use in North East England. The study was undertaken over a 28 week period and found: i) No significant difference in net ecosystem respiration (NER) between soils containing charcoal and those without, other than in week 1 of the trial. ii) A significantly higher dissolved organic carbon (DOC) flux from soils containing large amounts of charcoal than from those untreated, when planted with ryegrass. iii) That when increased respiration or DOC loss did occur, neither was sufficiently large to alter the carbon sink benefits of charcoal application. iv) That charcoal incorporation resulted in a significantly lower nitrate flux in soil leachate from mineral soils. v) That charcoal incorporation caused significant increases in soil pH, from 6.98 to 7.22 on bare arable soils when 87,500 kg charcoal/ha was applied. Consideration of both the carbon sink and environmental benefits observed here suggests that charcoal application to temperate soils typical of North East England should be considered as a method of carbon sequestration. Before large scale land application is encouraged, further large scale trials should be undertaken to confirm the positive results of this research.

  11. [Sorption of amino acids from aqueous solutions on activated charcoal].

    PubMed

    Nekliudov, A D; Tsibanov, V V

    1985-03-01

    Various methods for quantitative description of amino acid sorption from solutions for parenteral nutrition on activated charcoal were studied under dynamic and static conditions. With the use of the well-known Freindlich and Langmuir absorption isotherms it was shown to be possible to describe in a simplified way the complex multicomponent process of sorption of the amino acids and to estimate their loss at the filtration stage.

  12. Black carbon quantification in charcoal-enriched soils by differential scanning calorimetry

    NASA Astrophysics Data System (ADS)

    Hardy, Brieuc; Cornelis, Jean-Thomas; Leifeld, Jens

    2015-04-01

    Black carbon (BC), the solid residue of the incomplete combustion of biomass and fossil fuels, is ubiquitous in soil and sediments, fulfilling several environmental services such as long-term carbon storage. BC is a particularly important terrestrial carbon pool due to its large residence time compared to thermally unaltered organic matter, which is largely attributed to its aromatic structure. However, BC refers to a wide range of pyrogenic products from partly charred biomass to highly condensed soot, with a degree of aromaticity and aromatic condensation varying to a large extend across the BC continuum. As a result, BC quantification largely depends on operational definitions, with the extraction efficiency of each method varying across the entire BC range. In our study, we investigated the adequacy of differential scanning calorimetry (DSC) for the quantification of BC in charcoal-enriched soils collected in the topsoil of pre-industrial charcoal kilns in forest and cropland of Wallonia, Belgium, where charcoal residues are mixed to uncharred soil organic matter (SOM). We compared the results to the fraction of the total organic carbon (TOC) resisting to K2Cr2O7 oxidation, another simple method often used for BC measurement. In our soils, DSC clearly discriminates SOM from chars. SOM is less thermally stable than charcoal and shows a peak maximum around 295°C. In forest and agricultural charcoal-enriched soils, three peaks were attributed to the thermal degradation of BC at 395, 458 and 523°C and 367, 420 and 502 °C, respectively. In cropland, the amount of BC calculated from the DSC peaks is closely related (slope of the linear regression = 0.985, R²=0.914) to the extra organic carbon content measured at charcoal kiln sites relative to the charcoal-unaffected adjacent soils, which is a positive indicator of the suitability of DSC for charcoal quantification in soil. The first BC peak, which may correspond to highly degraded charcoal, contributes to a

  13. Gas and Chemical Activation of Charcoal

    DTIC Science & Technology

    1945-06-29

    supplemented ’ by runs in the laboratory has shown that zinc chloride is by far the most suitable activating agent. 1. In the dehydration mixing of...istics with time of dehydration . 3. The physical appearance of the mixture during the impregnation pperation provides sufficient significant information...to enable the operator to predict .mechanical characteristics of the briquet. CONFIDENTIAL " • ’< i£: • CONFIDENTIAL -4- 4* In the dehydration

  14. Comparison of Impurities in Charcoal Sorbents Found by Neutron Activation Analysis

    SciTech Connect

    Doll, Charles G.; Finn, Erin C.; Cantaloub, Michael G.; Greenwood, Lawrence R.; Kephart, Jeremy; Kephart, Rosara F.

    2013-01-01

    Abstract: Neutron activation of gas samples in a reactor often requires a medium to retain sufficient amounts of the gas for analysis. Charcoal is commonly used to adsorb gas and hold it for activation; however, the amount of activated sodium in the charcoal after irradiation swamps most signals of interest. Neutron activation analysis (NAA) was performed on several commonly available charcoal samples in an effort to determine the activation background. The results for several elements, including the dominant sodium element, are reported. It was found that ECN charcoal had the lowest elemental background, containing sodium at 2.65 ± 0.05 ppm, as well as trace levels of copper and tungsten.

  15. Binding Potency of Heparin Immobilized on Activated Charcoal for DNA Antibodies.

    PubMed

    Snezhkova, E A; Tridon, A; Evrard, B; Nikolaev, V G; Uvarov, V Yu; Tsimbalyuk, R S; Ivanuk, A A; Komov, V V; Sakhno, L A

    2016-02-01

    In vitro experiments showed that heparin adsorbed on activated charcoal can bind antibodies raised against native and single-stranded DNA in a diluted sera pool with a high level of these DNA. Thus, heparin used as anticoagulant during hemosorption procedure can demonstrate supplementary therapeutic activity resulting from its interaction with various agents involved in acute and chronic inflammatory reactions such as DNA- and RNA-binding substances, proinflammatory cytokines, complement components, growth factors, etc. Research and development of heparin-containing carbonic adsorbents for the therapy of numerous inflammatory and autoimmune diseases seems to be a promising avenue in hematology.

  16. Tailoring the characteristics of carbonized wood charcoal by using different heating rates

    NASA Astrophysics Data System (ADS)

    Kwon, Gu-Joong; Kim, Dae-Young; Oh, Choong-Hyeon; Park, Byung-Ho; Kang, Joo-Hyon

    2014-05-01

    This study examined the characteristics of charcoals generated from White Lauan ( Pentacmecontorta) and Punah ( Tetrameristaglabra) by using different carbonization temperatures and heating rates. The scanning electron micrographs showed vestured pits in the White Lauan and raphide crystals in Punah as their respective anatomical characteristics. A slower heating rate resulted in a lower temperature to obtain the same amount of weight loss, regardless of the species being tested. A greater charcoal yield was obtained at a higher heating rate. The specific surface area was smaller in the charcoal produced at a higher carbonization temperature, but the heating rate had little effected. For both wood species, the axial compressive strength of the charcoal increased as the carbonization temperature was increased. The X-ray diffractograms of White Lauan and Punah woods heated at 1200°C indicated thermal decomposition of the crystal structure of cellulose, but no appreciable structural changes occurred under the tested heating rate conditions. Overall, the heating rate affected the charcoal yield but not the specific surface area, compressive strength, and crystal structure.

  17. VOST charcoal specification study

    SciTech Connect

    Fuerst, R.G.; Foster, A.L.; Bursey, J.T.

    1996-12-31

    The volatile organic sampling train (VOST) is currently one the leading methodologies available for the sampling and analysis of volatile principal organic hazardous constituents (POHCs) and products of incomplete combustion (PICs) from stationary sources at very low levels. However, revisions to the original method are necessary to maintain VOST as a viable regulatory tool. To provide performance specifications and identify a replacement for SKC Lot 104 charcoal, a VOST charcoal specification study was initiated. The following carbon-based candidate sorbents were considered: Tenax-GR (a graphitized Tenax); a Petroleum-based Charcoal; Ambersorbe XE-340 (hydrophobic carbonized resin bead); Anasorb 747 (beaded active carbon with very regular pore size); Carbosieve{reg_sign} S-III (carbon molecular sieve); and a Beaded Activated Charcoal (BAC) (with a very regular pore size). The results indicated that Tenax-GR showed significantly poorer performance than the other candidates in preliminary experimental results. Ambersorb did not retain the gaseous volatile organic compounds tested as well as the others and recovery of vinyl chloride was very low at all levels of spiking. Carbosieve was eliminated as a candidate replacement because of cost and handling problems. The petroleum-based charcoal was eliminated because of difficulties in handling a finely-divided powder. The availability of Anasorb 747 proved to be the deciding factor between it and the BAC. Performance, cost, ease of handling, and plentiful supply make Anasorb{reg_sign} 747 a good choice for replacement of SKC Lot 104. 1 tab.

  18. An EELS-based study of the effects of pyrolysis on natural carbonaceous materials used for activated charcoal preparation.

    PubMed

    Jeanne-Rose, V; Golabkan, V; Mansot, J L; Largitte, L; Césaire, T; Ouensanga, A

    2003-04-01

    Electron energy-loss spectroscopy (EELS) has been used to characterize the electronic structure of charcoal phases at the nanoscale, thus demonstrating that the technique can be applied to environmental science. Activated charcoal is extensively used to remove pollutants from liquid and gaseous sewage. It is mainly obtained by activation of coke or charcoal produced from ligneous precursors. The present study concerns the use of by-products of local Caribbean agriculture, such as sugar cane bagasse, fruit stones and seeds, for use as activated charcoal precursors. Charcoal phases are prepared by high-temperature pyrolysis of lignocellulosic raw materials under a nitrogen gas flow. With the aim of optimizing the pyrolysis temperature and duration and oxygen content, the concentration of carbon sp2 hybridized chemical bonds and structural ordering have been followed by EELS for different treatment temperatures. To quantify the carbon sp2 content, near edge structure (NES) at the carbon K edge has been measured to determine the strength of pi --> pi* and 1s --> pi* transitions. Three precursors of plant origin, shells of Terminalia catappa and Acrocomia karukerana and seeds of Psidium guajava, with the pyrolysis temperatures between 600 and 900 degrees C, were investigated. The fraction of carbon sp2 bonding is found to increase when the temperature rises from 600 degrees C to the range 700-750 degrees C and becomes stable at higher temperatures. For temperatures in excess of 700 degrees C, structural ordering probably occurs and well-defined 1s --> sigma* NES is present, whose intensity increases with increasing preparation temperature. For the highest temperature of around 900 degrees C, the structure of the final product is less well organized than graphitized carbon but a few per cent of a highly ordered phase is found.

  19. Some Investigations of the Reaction of Activated Charcoal with Fluorine and Uranium Hexafluoride

    SciTech Connect

    Del Cul, G.D.; Fiedor, J.N.; Simmons, D.W.; Toth, L.M.; Trowbridge, L.D.; Williams

    1998-09-01

    The Molten Salt Reactor Experiment (MSRE) at Oak Ridge National Laboratory has been shut down since 1969, when the fuel salt was drained from the core into two Hastelloy N drain tanks at the reactor site. Over time, fluorine (F{sub 2}) and uranium hexafluoride (UF{sub 6}) moved from the salt through the gas piping to a charcoal bed, where they reacted with the activated charcoal. Some of the immediate concerns related to the migration of F{sub 2} and UF{sub 6} to the charcoal bed were the possibility of explosive reactions between the charcoal and F{sub 2}, the existence of conditions that could induce a criticality accident, and the removal and recovery of the fissile uranium from the charcoal. This report addresses the reactions and reactivity of species produced by the reaction of fluorine and activated charcoal and between charcoal and F{sub 2}-UF{sub 6} gas mixtures in order to support remediation of the MSRE auxiliary charcoal bed (ACB) and the recovery of the fissile uranium. The chemical identity, stoichiometry, thermochemistry, and potential for explosive decomposition of the primary reaction product, fluorinated charcoal, was determined.

  20. Soil charcoal as long-term pyrogenic carbon storage in Amazonian seasonal forests.

    PubMed

    Turcios, Maryory M; Jaramillo, Margarita M A; do Vale, José F; Fearnside, Philip M; Barbosa, Reinaldo Imbrozio

    2016-01-01

    Forest fires (paleo + modern) have caused charcoal particles to accumulate in the soil vertical profile in Amazonia. This forest compartment is a long-term carbon reservoir with an important role in global carbon balance. Estimates of stocks remain uncertain in forests that have not been altered by deforestation but that have been impacted by understory fires and selective logging. We estimated the stock of pyrogenic carbon derived from charcoal accumulated in the soil profile of seasonal forest fragments impacted by fire and selective logging in the northern portion of Brazilian Amazonia. Sixty-nine soil cores to 1-m depth were collected in 12 forest fragments of different sizes. Charcoal stocks averaged 3.45 ± 2.17 Mg ha(-1) (2.24 ± 1.41 Mg C ha(-1) ). Pyrogenic carbon was not directly related to the size of the forest fragments. This carbon is equivalent to 1.40% (0.25% to 4.04%) of the carbon stocked in aboveground live tree biomass in these fragments. The vertical distribution of pyrogenic carbon indicates an exponential model, where the 0-30 cm depth range has 60% of the total stored. The total area of Brazil's Amazonian seasonal forests and ecotones not altered by deforestation implies 65-286 Tg of pyrogenic carbon accumulated along the soil vertical profile. This is 1.2-2.3 times the total amount of residual pyrogenic carbon formed by biomass burning worldwide in 1 year. Our analysis suggests that the accumulated charcoal in the soil vertical profile in Amazonian forests is a substantial pyrogenic carbon pool that needs to be considered in global carbon models.

  1. Carbon sequestration and fertility after centennial time scale incorporation of charcoal into soil

    NASA Astrophysics Data System (ADS)

    Criscuoli, Irene; Alberti, Giorgio; Baronti, Silvia; Favilli, Filippo; Martinez, Cristina; Calzolari, Costanza; Pusceddu, Emanuela; Rumpel, Cornelia; Viola, Roberto; Miglietta, Franco

    2014-05-01

    The addition of pyrogenic carbon (C) in the soil is considered a sustainable strategy to achieve direct C sequestration and potential reduction of non-CO2 greenhouse gas emissions. In this paper, we investigated the long term effects of charcoal addition on C sequestration and soil chemico-physical properties by studying a series of abandoned charcoal hearths in the Eastern Alps established in the XIX century. This natural setting can be seen as an analogue of a deliberate experiment with replications. Carbon sequestration was assessed indirectly by comparing the amount of C present in the hearths with the estimated amount of charcoal that was left on the soil after the carbonization. Approximately 80% of the C originally added to the soil via charcoal can still be found today, thus supporting the view that charcoal incorporation is an effective way to sequester atmospheric CO2. We also observed an improvement in the physical properties (hydrophobicity and bulk density) of charcoal hearth soils and an accumulation of nutrients compared to the adjacent soil without charcoal. Then, we focused on the morphological and physical characterization of several fragments, using scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF). Such study enabled the identification of peculiar morphological features of tracheids, which were tentatively associated to a differential oxidation of the structures that were created during carbonization from lignine and cellulose. In order to assess the effect of soil-aging we compared the old-biochar with a modern one obtained from the same feedstock and with similar carbonization process. XRD and XRF analysis were performed on both old and modern biochar, in order to study the multiphase crystalline structure and chemical elements found. We observed mineralization and a fossilization of old biochar samples respect to the modern ones, with accumulation of several mineral oxides and a substantial presence of

  2. Investigation on cotton stalk and bamboo sawdust carbonization for barbecue charcoal preparation.

    PubMed

    Xiong, Shaowu; Zhang, Shouyu; Wu, Qiaomei; Guo, Xi; Dong, Aixia; Chen, Chuan

    2014-01-01

    In the paper, biochar preparation from cotton stalk and bamboo sawdust by carbonization process was addressed. The physical and chemical properties and combustion characteristics of the biochar prepared using a tubular fixed bed were investigated. The combustion character index (S), the ignition temperature (Ti) and burnout temperature (Tf) were used to evaluate the combustion characteristics of the biochars. The results indicate that the yield and the volatile yield of the biochar decrease and the fixed carbon yield increases with the increase of the carbonization temperature. The ignition temperature and burnout temperature of the biochar increase and the value of S decreases when the carbonization temperature increases. The biochar produced from cotton stalk shows better combustion characteristics than the bamboo sawdust biochar does. Compared with commercial barbecue charcoal, the cotton stalk biochar produced under 600 °C can be utilized as barbecue charcoal.

  3. Radon-222 activity flux measurement using activated charcoal canisters: revisiting the methodology.

    PubMed

    Alharbi, Sami H; Akber, Riaz A

    2014-03-01

    The measurement of radon ((222)Rn) activity flux using activated charcoal canisters was examined to investigate the distribution of the adsorbed (222)Rn in the charcoal bed and the relationship between (222)Rn activity flux and exposure time. The activity flux of (222)Rn from five sources of varying strengths was measured for exposure times of one, two, three, five, seven, 10, and 14 days. The distribution of the adsorbed (222)Rn in the charcoal bed was obtained by dividing the bed into six layers and counting each layer separately after the exposure. (222)Rn activity decreased in the layers that were away from the exposed surface. Nevertheless, the results demonstrated that only a small correction might be required in the actual application of charcoal canisters for activity flux measurement, where calibration standards were often prepared by the uniform mixing of radium ((226)Ra) in the matrix. This was because the diffusion of (222)Rn in the charcoal bed and the detection efficiency as a function of the charcoal depth tended to counterbalance each other. The influence of exposure time on the measured (222)Rn activity flux was observed in two situations of the canister exposure layout: (a) canister sealed to an open bed of the material and (b) canister sealed over a jar containing the material. The measured (222)Rn activity flux decreased as the exposure time increased. The change in the former situation was significant with an exponential decrease as the exposure time increased. In the latter case, lesser reduction was noticed in the observed activity flux with respect to exposure time. This reduction might have been related to certain factors, such as absorption site saturation or the back diffusion of (222)Rn gas occurring at the canister-soil interface.

  4. Fabrication of Activated Rice Husk Charcoal by Slip Casting as a Hybrid Material for Water Filter Aid

    NASA Astrophysics Data System (ADS)

    Tuaprakone, T.; Wongphaet, N.; Wasanapiarnpong, T.

    2011-04-01

    Activated charcoal has been widely used as an odor absorbent in household and water purification industry. Filtration equipment for drinking water generally consists of four parts, which are microporous membrane (porous alumina ceramic or diatomite, or porous polymer), odor absorbent (activated carbon), hard water treatment (ion exchange resin), and UV irradiation. Ceramic filter aid is usually prepared by slip casting of alumina or diatomite. The membrane offers high flux, high porosity and maximum pore size does not exceed 0.3 μm. This study investigated the fabrication of hybrid activated charcoal tube for water filtration and odor absorption by slip casting. The suitable rice husk charcoal and water ratio was 48 to 52 wt% by weight with 1.5wt% (by dry basis) of CMC binder. The green rice husk charcoal bodies were dried and fired between 700-900 °C in reduction atmosphere. The resulting prepared slip in high speed porcelain pot for 60 min and sintered at 700 °C for 1 h showed the highest specific surface area as 174.95 m2/g. The characterizations of microstructure and pore size distribution as a function of particle size were investigated.

  5. Highly stable rice-straw-derived charcoal in 3700-year-old ancient paddy soil: evidence for an effective pathway toward carbon sequestration.

    PubMed

    Wu, Mengxiong; Yang, Min; Han, Xingguo; Zhong, Ting; Zheng, Yunfei; Ding, Pin; Wu, Weixiang

    2016-01-01

    Recalcitrant charcoal application is predicted to decelerate global warming through creating a long-term carbon sink in soil. Although many studies have showed high stability of charcoal derived from woody materials, few have focused on the dynamics of straw-derived charcoal in natural environment on a long timescale to evaluate its potential for agricultural carbon sequestration. Here, we examined straw-derived charcoal in an ancient paddy soil dated from ~3700 calendar year before present (cal. year BP). Analytical results showed that soil organic matter consisted of more than 25% of charcoal in charcoal-rich layer. Similarities in morphology and molecular structure between the ancient and the fresh rice-straw-derived charcoal indicated that ancient charcoal was derived from rice straw. The lower carbon content, higher oxygen content, and obvious carbonyl of the ancient charcoal compared with fresh rice straw charcoal implied that oxidation occurred in the scale of thousands years. However, the dominant aromatic C of ancient charcoal indicated that rice-straw-derived charcoal was highly stable in the buried paddy soil due to its intrinsic chemical structures and the physical protection of ancient paddy wetland. Therefore, it may suggest that straw charcoal application is a potential pathway for C sequestration considering its longevity.

  6. Comparison between measurements of black carbon, charcoal and associated nutrients in western Amazonan soils

    NASA Astrophysics Data System (ADS)

    Zimmerman, A. R.; McMichael, C.; Hanlon, C.; Bush, M. B.

    2011-12-01

    To construct fire and climate history and human occupation records from soils and lake sediment profiles, climatologists and anthropologists have traditionally measured charcoal abundances by microscopic image analysis. In contrast, geochemists have developed methods of black carbon (BC) quantification using chemical extraction. We compared charcoal (>0.5 mm particle size) versus BC (measured via the CTO-340 method of Kuhlbusch, 1995) in multiple soil profiles from four western Amazon regions with evidence of pre-Columbian occupation. A secondary goal of this project was to understand the relative influence of climate and humans in the fire and ecological history of the Amazon. BC concentration in soils of the Amazon varied widely from an average of 0.5 mg g 1 in cores around Lake Gentry (southeastern Peru) to 5.5 mg g 1 around Lake Ayauchi (southeastern Ecuador), corresponding to the evidence of greater land use around the latter. Surprising, BC concentrations in habitation horizon soils at Quistococha, near Iquitos, Peru were similar to Lake Gentry, averaging about 0.6 mg g 1. However, BC as a percent of soil organic carbon (SOC) was much more uniform with an average of 12.0, 13.3, 14.6, and 13.0% in Quistococha, Gentry, Ayauchi, and Los Amigos (central-eastern Peru) soils, respectively, suggesting that the same processes that concentrate SOC also concentrate BC. BC may act to protect SOC via sorption or produce SOC via microbial community enhancement. These findings also show that BC is not regionally enriched as it might be were climate to be a predominant factor in BC production, and seem to track land use more closely. Charcoal and BC concentrations were linearly correlated in only about half the soil profiles and neither BC nor charcoal were consistently correlated with chemical anthropogenic indicators such as P or Ca within soil profiles or specific regions. However, there was a statistical covariance between each of these parameters suggesting that each

  7. Using Macroscopic Charcoal to Reconstruct the Holocene Fire Activity of the Willamette Valley, Oregon and Washington

    NASA Astrophysics Data System (ADS)

    Walsh, M. K.; Whitlock, C.; Bartlein, P. J.; Pearl, C. A.

    2006-12-01

    High-resolution macroscopic charcoal analysis of two lacustrine records has revealed the Holocene fire activity of the Willamette Valley, located between the Coast and Cascade ranges of southwestern Washington and northwestern Oregon. The Willamette Valley experienced major environmental and cultural changes during the Holocene, however, its long-term fire history is poorly known. Of particular interest are shifts in fire activity that occurred in response to (1) millennial- and centennial-scale climate and vegetation changes (e.g., the Early Holocene warm period, the Little Ice Age) and (2) major shifts in human activity and population size (e.g., Native American population decline, Euro-American settlement). Macroscopic charcoal analysis of contiguous core samples was used to reconstruct fire activity at each site. Charcoal source (i.e., herbaceous or woody) was also determined based on particle morphology. Charcoal influx was decomposed into a peak component (which indicates fire episodes) and a background component (which indicates changes in burnable biomass). Charcoal records from Battle Ground Lake and Beaver Lake reveal major shifts in fire activity that are consistent with known changes in regional climate on orbital time scales. The Battle Ground Lake charcoal data, for example, show a general increase in fire frequency from the beginning of the Holocene to a maximum of ~18 fire episodes/1000 years at 6500 cal yr BP, associated with the early Holocene insolation maximum and its influence on summer drought, followed by a decrease to ~5 fire episodes/1000 years at present. Similar trends are indicated by the Beaver Lake charcoal data. Both records also indicate shifts in fire activity that suggest the possibility of anthropogenic burning, but at different times at each site. Additional records are being analyzed to examine the spatial and temporal patterns of fire activity across the Willamette Valley as a whole.

  8. In vitro analysis of the effect of supplementation with activated charcoal on the equine hindgut

    PubMed Central

    EDMUNDS, J.L.; WORGAN, H.J.; DOUGAL, K.; GIRDWOOD, S.E.; DOUGLAS, J.-L.; MCEWAN, N.R.

    2016-01-01

    ABSTRACT The present study uses in vitro analytical techniques to investigate the effect of activated charcoal on the microbial community of the equine hindgut and the metabolites they produce. Incubations were performed in Wheaton bottles using a 50 ml incubation of a high-energy feed or a low-energy feed, plus bottles with no added food source, together with five levels of activated charcoal (0, 10, 25, 50 or 100 mg per bottle) and fecal samples as a bacterial inoculum. Using this method the rate of gas production, volatile fatty acid and ammonia concentrations, and pH values were analyzed and found to vary depending on the addition of feed, but the activated charcoal had no effect (P>0.05) on any of these. It is already believed that the effect of activated charcoal as a control for toxic substances is at its highest in the foregut or midgut of animals, and therefore should have little impact on the hindgut. The data presented here suggest that if any of the activated charcoal does reach the hindgut, then it has no significant impact on the microbial community present, nor on the major metabolites produced, and so should not have a detrimental effect on the principal site of fermentation in the horse. PMID:27330398

  9. Development and optimization of the activated charcoal suspension composition based on a mixture design approach.

    PubMed

    Ronowicz, Joanna; Kupcewicz, Bogumiła; Pałkowski, Łukasz; Krysiński, Jerzy

    2015-03-01

    In this study, a new drug product containing activated charcoal was designed and developed. The excipient levels in the pharmaceutical formulation were optimized using a mixture design approach. The adsorption power of the activated charcoal suspension was selected as the critical quality attribute influencing the efficacy of medical treatment. Significant prognostic models (p<0.05) were obtained to describe in detail the interrelations between excipient levels and the adsorption power of the formulation. Liquid flavour had a critical impact on the adsorption power of the suspension. Formulations containing the largest amount of liquid flavour showed the lowest adsorption power. Sorbitol was not adsorbed onto activated charcoal so strongly as liquid flavour. A slight increase in the content of carboxymethylcellulose sodium led to a marked decrease in adsorption power. The obtained mathematical models and response surface allowed selection of the optimal composition of excipients in a final drug product.

  10. Evaluation of fructooligosaccharides separation using a fixed-bed column packed with activated charcoal.

    PubMed

    Kuhn, Raquel Cristine; Mazutti, Marcio A; Albertini, Lilian Buoro; Filho, Francisco Maugeri

    2014-05-25

    Recent studies have shown that the chromatographic separation of mixtures of saccharides may be improved by making use of activated charcoal, a promising low cost material for the separation of sugars, including fructooligosaccharides. In this work, the development of a methodology to separate fructooligosaccharides from glucose, fructose and sucrose, using a fixed bed column packed with activated charcoal is proposed. The influence of temperature, eluant concentration and step gradients were evaluated to increase the separation efficiency and fructooligosaccharide purity. The final degree of fructooligosaccharide purification and separation efficiency were about 94% and 3.03 respectively, using ethanol gradient concentration ranging from 3.5% to 15% (v/v) at 40°C. The fixed bed column packed with the activated charcoal was shown to be a promising alternative for sugar separation, mainly those rich in fructooligosaccharides, leading to solutions of acceptable degrees of purification.

  11. Molecular and structural properties of polymer composites filled with activated charcoal particles

    NASA Astrophysics Data System (ADS)

    Tahir, Dahlang; Liong, Syarifuddin; Bakri, Fahrul

    2016-03-01

    We have studied the molecular properties, structural properties, and chemical composition of composites by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy, and X-ray fluorescence (XRF) spectroscopy, respectively. FTIR spectra shows absorption band of hydroxyl group (-OH), methyl group (-CH3) and aromatic group (C-C). The absorption band for aromatic group (C-C) shows the formation of carbonaceous in composites. XRF shows chemical composition of composites, which the main chemicals are SO3, Cl, and ZnO. The loss on ignition value (LOI) of activated charcoal indicates high carbonaceous matter. The crystallite size for diffraction pattern from hydrogel polymer is about 17 nm and for activated charcoal are about 19 nm. The crystallite size of the polymer is lower than that of activated charcoal, which make possible of the particle from filler in contact with each other to form continuous conducting polymer through polymer matrix.

  12. Combining charcoal and elemental black carbon analysis in sedimentary archives: Implications for past fire regimes, the pyrogenic carbon cycle, and the human-climate interactions

    NASA Astrophysics Data System (ADS)

    Thevenon, Florian; Williamson, David; Bard, Edouard; Anselmetti, Flavio S.; Beaufort, Luc; Cachier, Hélène

    2010-07-01

    This paper addresses the quantification of combustion-derived products in oceanic and continental sediments by optical and chemical approaches, and the interest of combining such methods for reconstructing past biomass burning activity and the pyrogenic carbon cycle. In such context, the dark particles > 0.2 µm 2 remaining after the partial digestion of organic matter are optically counted by automated image analysis and defined as charcoal, while the elemental carbon remaining after thermal and chemical oxidative treatments is quantified as black carbon (BC). The obtained pyrogenic carbon records from three sediment core-based case studies, (i) the Late Pleistocene equatorial Pacific Ocean, (ii) the mid-Holocene European Lake Lucerne, and (iii) the Late Holocene African Lake Masoko, are interpreted as proxy records of regional transportation mechanisms and biomass burning activities. The results show that the burial of dark carbon-rich particles in the 360 kyr-long record from the west equatorial Pacific is controlled by the combination of sea-level changes and low-latitude atmospheric circulation patterns (summer monsoon dynamics). However, the three fold increases in charcoal and BC sediment influxes between 53-43 and 12-10 kyr BP suggest that major shifts in fire activity occur synchronously with human colonization in the Indo/Pacific region. The coarse charcoal distribution from a 7.2 kyr record from Lake Lucerne in Switzerland closely matches the regional timing of major technical, land-use, and socio-economic changes during the Neolithic (between ca. 5.7 and 5.2 kyr BP and 4.9-4.5 kyr BP), the Bronze and Iron Ages (at ca. 3.3 and 2.4 kyr BP, respectively), and the industrialization (after AD 1838), pointing to the key impact of human activities on the sources, transportation processes and reservoirs of refractory carbon during the Holocene. In the tropical Masoko maar lake in Tanzania, where charcoal and BC records are highly sensitive to the local climate

  13. Fractionation of honey carbohydrates using pressurized liquid extraction with activated charcoal.

    PubMed

    Ruiz-Matute, A I; Ramos, L; Martínez-Castro, I; Sanz, M L

    2008-09-24

    This article describes the development of a new procedure that combines the use of activated charcoal and pressurized liquid extraction (PLE) to obtain enriched fractions of di- and trisaccharides from honey. Honey was adsorbed onto activated charcoal and packed into a PLE extraction cell. Optimum results were obtained at 10 MPa and 40 degrees C using two consecutive PLE cycles: first, 1:99 (v/v) ethanol/water for 5 min and second, 50:50 (v/v) ethanol/water for 10 min. Di- and trisaccharide fractions were enriched after PLE treatment, accounting for 73% and 8% of total carbohydrates, respectively. This procedure was also compared with other methodologies reported in the literature for the fractionation of honey carbohydrates (yeast treatment and extraction from activated charcoal). While the removal of monosaccharides was more efficient with yeast treatment, recovery of di- and trisaccharides was higher when either the PLE or the activated charcoal treatment was used. PLE was found to be the faster technique; it also required less solvent volume and minimized handling of the sample.

  14. Effect of supplementing activated charcoal on the intake of honey mesquite leaves by lambs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to determine if intake of honey mesquite (Prosopis glandulosa Torr.) leaves by sheep could be increased by supplementing four levels of activated charcoal supplemental (0.0, 0.33, 0.67 and 1.00 g/kg of BW). Twenty wether lambs (36.6 ± 0.6 kg) were randomly assigned to the 4 tre...

  15. Effect of supplementing activated charcoal on the intake of honey mesquite leaves by lambs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to determine if intake of honey mesquite (Prosopis glandulosa Torr.) leaves by sheep could be increased by supplementing activated charcoal at 0.0, 0.33, 0.67 or 1.00 g / kg of body weight. Twenty wether lambs (36.6 ± 0.6 kg) were randomly assigned to the 4 treatment levels. La...

  16. Detection of 5 CFU/g of Escherichia coli O157:H7 on lettuce using activated charcoal and real-time PCR without enrichment.

    PubMed

    Lee, Jung-Lim; Levin, Robert E

    2011-05-01

    A sample treatment method which separates Escherichia coli O157:H7 from lettuce and removes PCR inhibitors allowing 5 CFU/g of target cells to be detected using real-time PCR is described. Lettuce leaves inoculated with E. coli O157:H7 were rinsed with 0.025% sodium dodecyl sulfate (SDS). In this study, there were two major factors that strongly affected the recovery of E. coli O157:H7 during sample preparation, the amount of bentonite coated activated charcoal used to remove PCR inhibitors and the agitated contact time of the samples with the coated charcoal. When 3.0 g of activated carbon coated with bentonite were mixed with target cell suspensions (30 ml) derived from 50 g of lettuce, a high recovery of E. coli O157:H7 (93%) was obtained. Sample agitation with bentonite coated activated charcoal for 15 min resulted in 95% recovery of E. coli O157:H7. When a commercial DNA purification resin was used for detection of E. coli O157:H7 without the use of the bentonite treated charcoal, the real-time PCR (Rti-PCR) failed to detect 1 × 10(2) CFU/g. In contrast, with the use of use of bentonite coated activated charcoal and a commercial DNA purifying resin together, Rti-PCR was able to detect 5 CFU of E. coli O157:H7/g of lettuce which was equivalent to 2.8 CFU/Rti-PCR. Such a successful detection level was the result of the bentonite coated activated charcoal's ability to absorb the PCR inhibitors released from seeded lettuce during detachment. A standard curve was generated by plotting the Ct values against the log of CFU of target bacterial cells. A linear range of DNA amplification was exhibited from 5.0 × 10(0) to 1.0 × 10(4) CFU/g by using Rti-PCR.

  17. Supercritical Carbon Dioxide Regeneration of Activated Carbon Loaded with Contaminants from Rocky Mountain Arsenal Well Water.

    DTIC Science & Technology

    1982-05-01

    15 111-7 GRANULAR ACTIVATED CARBON ADSORPTION ISOTHERMS THERMALLY REACTIVATED CARBON .............. 16 I IV-1 PROCESS FLOW DIAGRAM FOR... PROCESSING COST OF ACTIVATED CHARCOAL REGENERATION BY SUPERCRITICAL CARBON DIOXIDE PROCESS ........................... 25 l IV-4 SENSITIVITY OF GAC...regenerate adsorbents such as granular activated carbon loaded with a broad variety of organic adsorbates. This regeneration process uses a supercritical

  18. Rainforest burning and the global carbon budget: Biomass, combustion efficiency, and charcoal formation in the Brazilian Amazon

    NASA Astrophysics Data System (ADS)

    Fearnside, Philip M.; Leal, Niwton; Fernandes, Fernando Moreira

    1993-01-01

    Biomass present before and after burning was measured in forest cleared for pasture in a cattle ranch (Fazenda Dimona) near Manaus, Amazonas, Brazil. Aboveground dry weight biomass loading averaged 265 t ha-1 (standard deviation (SD) = 110, n = 6 quadrats) at Fazenda Dimona, which corresponds to approximately 311 t ha-1 total dry weight biomass. A five-category visual classification at 200 points showed highly variable burn quality. Postburn aboveground biomass loading was evaluated by cutting and weighing of 100 m2 quadrats and by line intersect sampling. Quadrats had a mean dry weight of 187 t ha-1 (SD = 69, n = 10), a 29.3% reduction from the preburn mean in the same clearing. Line intersect estimates in 1.65 km of transects indicated that 265 m3 ha-1 (approximately 164 t ha-1 of aboveground dry matter) survived burning. Using carbon contents measured for different biomass components (all ˜50% carbon) and assuming a carbon content of 74.8% for charcoal (from other studies near Manaus), the destructive measurements imply a 27.6% reduction of aboveground carbon pools. Charcoal composed 2.5% of the dry weight of the remains in the postburn destructive quadrats and 2.8% of the volume in the line intersect transects. Thus approximately 2.7% of the preburn aboveground carbon stock was converted to charcoal, substantially less than is generally assumed in global carbon models. The findings confirm high values for biomass in central Amazonia. High variability indicates the need for further studies in many localities and for making maximum use of less laborious indirect methods of biomass estimation. While indirect methods are essential for regional estimates of average biomass, only direct weighing such as that reported here can yield information on combustion efficiency and charcoal formation. Both high biomass and low percentage of charcoal formation suggest the significant potential contribution of forest burning to global climate changes from CO2 and trace gases.

  19. Rainforest burning and the global carbon budget: Biomass, combustion efficiency, and charcoal formation in the Brazilian Amazon

    SciTech Connect

    Fearnside, P.M.; Leal, N. Jr.; Fernandes, F.M.

    1993-09-20

    Biomass present before and after burning was measured in forest cleared for pasture in a cattle ranch (Fazenda Dimona) near Manaus, Amazonas, Brazil. Aboveground dry weight biomass loading averaged 265 t ha{sup {minus}1} (standard deviation (SD) = 110, n = 6 quadrats) at Fazenda Dimonas. Postburn aboveground biomass loading was evaluated by cutting and weighing of 100 m{sup 2} quadrats and by line intersect sampling. Quadrats had a mean dry weight of 187 t ha{sup {minus}1} (SD = 69, n = 10), a 29.3% reduction from the preburn mean in the same clearing. Line intersect estimates in 1.65 km of transects indicated that 265 m{sup 3} ha{sup {minus}1} (approximately 164 t ha{sup {minus}1} of aboveground dry matter) survived burning. Using carbon contents measured for different biomass components (all {approximately} 50% carbon) and assuming a carbon content of 74.8% for charcoal (from other studies near Manaus), the destructive measurements imply a 27.6% reduction of aboveground carbon pools. Charcoal composed 2.5% of the dry weight of the remains in the postburn destructive quadrats and 2.8% of the volume in the line intersect transects. Thus approximately 2.7% of the preburn aboveground carbon stock was converted to charcoal, substantially less than is generally assumed in global carbon models. The findings confirm high values for biomass in central Amazonia. High variability indicates the need for further studies in many localities and for making maximum use of less laborious indirect methods of biomass estimation. While indirect methods are essential for regional estimates of average biomass, only direct weighing such as that reported here can yield information on combustion efficiency and charcoal formation. Both high biomass and low percentage of charcoal formation suggest the significant potential contribution of forest burning to global climate changes from CO{sub 2} and trace gases. 66 refs., 6 figs., 2 tabs.

  20. Investigation of chemical and electrochemical reactions mechanisms in a direct carbon fuel cell using olive wood charcoal as sustainable fuel

    NASA Astrophysics Data System (ADS)

    Elleuch, Amal; Halouani, Kamel; Li, Yongdan

    2015-05-01

    Direct carbon fuel cell (DCFC) is a high temperature fuel cell using solid carbon as fuel. The use of environmentally friendly carbon material constitutes a promising option for the DCFC future. In this context, this paper focuses on the use of biomass-derived charcoal renewable fuel. A practical investigation of Tunisian olive wood charcoal (OW-C) in planar DCFCs is conducted and good power density (105 mW cm-2) and higher current density (550 mA cm-2) are obtained at 700 °C. Analytical and predictive techniques are performed to explore the relationships between fuel properties and DCFC chemical and electrochemical mechanisms. High carbon content, carbon-oxygen groups and disordered structure, are the key parameters allowing the achieved good performance. Relatively complex chain reactions are predicted to explain the gas evolution within the anode. CO, H2 and CH4 participation in the anodic reaction is proved.

  1. Evaluation of photocatalytic activities of supported catalysts on NaX zeolite or activated charcoal.

    PubMed

    de Brites-Nóbrega, Fernanda F; Polo, Aldino N B; Benedetti, Angélica M; Leão, Mônica M D; Slusarski-Santana, Veronice; Fernandes-Machado, Nádia R C

    2013-12-15

    This study aimed to evaluate the photocatalytic activity of ZnO and Nb2O5 catalysts, both supported on NaX zeolite and activated charcoal (AC). The synergistic effect between oxide and support and the influence of solution pH (3, 7 and 9) on photocatalytic degradation of reactive blue 5G (C.I. 222) were analyzed. The catalysts Nb2O5/NaX, Nb2O5/AC and ZnO/NaX, ZnO/AC with 5 and 10% (wt%) were prepared by wet impregnation. The results showed that the catalysts exhibit quite different structural and textural properties. The synergic effect between ZnO and NaX support was higher than that with the activated charcoal, showing that these catalysts were more efficient. The most photoactive catalyst was 10% ZnO/NaX which showed 100% discoloration of the dye solution at pH 3, 7 and 9 after 0.5, 5 and 2h of irradiation, respectively. The hydrolytic nature of zeolite favored the formation of surface hydroxyl radicals, which increased the activity of the photocatalyst. Thus, catalysts supported on NaX zeolite are promising for use in photocatalysis.

  2. Activated charcoal filter effectively reduces p-benzosemiquinone from the mainstream cigarette smoke and prevents emphysema.

    PubMed

    Dey, Neekkan; Das, Archita; Ghosh, Arunava; Chatterjee, Indu B

    2010-06-01

    In this paper, we have made a comparative evaluation of the cytotoxicity and pathophysiological effects of mainstream smoke from cellulose acetate (CA)-filtered cigarettes with that of charcoal-filtered cigarettes developed in our laboratory. Previously, we had demonstrated that the mainstream smoke from an Indian CA-filtered commercial cigarette contains p-benzosemiquinone (p-BSQ), a major, highly toxic, long-lived water-soluble radical. Here, we have examined 16 brands of different CA-filtered cigarettes including Kentucky research cigarettes, and observed that mainstream smoke from all the cigarettes contains substantial amounts of p-BSQ (100-200 μg/cigarette). We also show that when the CA filter is replaced by a charcoal filter, the amount of p-BSQ in the mainstream smoke is reduced by 73-80%, which is accompanied by a reduction of carbonyl formation in bovine serum albumin to the extent of 70- 90%. The charcoal filter also prevented cytotoxicity in A549 cells as evidenced by MTT assay, apoptosis as evidenced by FACS analysis, TUNEL assay, overexpression of Bax, activation of p53 and caspase 3, as well as emphysematous lung damage in a guinea pig model as seen by histology and morphometric analysis. The results indicate that the charcoal filter developed in our laboratory may protect smokers from cigarette smoke-induced cytotoxity, protein modification, apoptosis and emphysema.

  3. Quantification of Aridity Changes During the Late Holocene From the Carbon Isotope Composition of Fossil Charcoal

    NASA Astrophysics Data System (ADS)

    Voltas, J.; Ferrio, P.; Espinar, C.

    2006-12-01

    Climate dynamics during the Holocene can be characterized by a variety of proxies that provide information at a different scale and accuracy. In seasonally dry climates, the carbon isotope composition of tree-rings has been related to variables such as rainfall or evaporative demand. Extensive tree-ring records, however, are not always available owing to factors such as human-induced deforestation or harsh conditions for most long-lived trees to thrive. An illustrative example concerns the Mediterranean region. In this work, we aim to show that the original climate signal of wood δ13C is preserved in fossil charcoal (recovered from archaeological sites), and thus can be used to quantify past changes in water availability. We present two case studies on climate reconstruction at the temporal and spatial dimensions from Eastern Spain. We first describe, for a restricted area, the evolution of aridity during the last 4000 years using charcoals ranging from the Bronze Age (ca. 2100 BCE) to the Modern Age (XVIII ca. CE) (1). Further, we characterize, for a larger region, the transition between Bronze and Iron Ages, the so called Cold Iron Age Epoch (ca. 700-500 BCE), using remains from a set of contemporary sites (2). Climatic inferences were obtained after calibration of quantitative models predicting rainfall from wood δ13C. For case (1), charcoals of Mediterranean trees (Aleppo pine, several oaks, mastic) were analysed for δ13C. We found similar trends for the time course of changes in this parameter regardless of the species. Estimated rainfall in the past was 25% to 40% higher than present, with phases of greater water availability (1500-900 BCE; 300 BCE-300 CE) alternating with drier periods (900-300 BCE; 900-1100 CE). For case (2), we combined data from Aleppo pine and Holm oak, which exhibit differential responses to changes in climate seasonality, to provide information on intra-annual rainfall dynamics. The divergence in δ13C between pines and oaks can be

  4. Effect of electric current frequency on the activation kinetics of raw charcoal

    SciTech Connect

    Shevchenko, A.O.; Ivakhnyuk, G.K.; Fedorov, N.F.

    1993-12-10

    The effect of electric current frequency on the kinetics of raw charcoal activation with water vapor has been investigated. It was established that under the effect of alternating current the rate constant increases under otherwise equal conditions. A dependence of the reaction rate on the current frequency was found. It was discovered that under the effect of alternating current the activation energy of interaction with water vapor diminishes.

  5. Carbon emissions due to deforestation for the production of charcoal used in Brazil’s steel industry

    NASA Astrophysics Data System (ADS)

    Sonter, Laura J.; Barrett, Damian J.; Moran, Chris J.; Soares-Filho, Britaldo S.

    2015-04-01

    Steel produced using coal generates 7% of global anthropogenic CO2 emissions annually. Opportunities exist to substitute this coal with carbon-neutral charcoal sourced from plantation forests to mitigate project-scale emissions and obtain certified emission reduction credits under the Kyoto Protocol’s Clean Development Mechanism. This mitigation strategy has been implemented in Brazil and is one mechanism among many used globally to reduce anthropogenic CO2 emissions; however, its potential adverse impacts have been overlooked to date. Here, we report that total CO2 emitted from Brazilian steel production doubled (91 to 182 MtCO2) and specific emissions increased (3.3 to 5.2 MtCO2 per Mt steel) between 2000 and 2007, even though the proportion of coal used declined. Infrastructure upgrades and a national plantation shortage increased industry reliance on charcoal sourced from native forests, which emits up to nine times more CO2 per tonne of steel than coal. Preventing use of native forest charcoal could have avoided 79% of the CO2 emitted from steel production between 2000 and 2007; however, doing so by increasing plantation charcoal supply is limited by socio-economic costs and risks further indirect deforestation pressures and emissions. Effective climate change mitigation in Brazil’s steel industry must therefore minimize all direct and indirect carbon emissions generated from steel manufacture.

  6. Only small changes in soil organic carbon and charcoal concentrations found one year after experimental slash-and-burn in a temperate deciduous forest

    NASA Astrophysics Data System (ADS)

    Eckmeier, E.; Gerlach, R.; Skjemstad, J. O.; Ehrmann, O.; Schmidt, M. W. I.

    2007-02-01

    Anthropogenic fires affected the temperate deciduous forests of Central Europe over millennia. Biomass burning releases carbon to the atmosphere and produces charcoal, which potentially contributes to the stable soil carbon pools and is an important archive of environmental history. The fate of charcoal in soils of temperate deciduous forests, i.e. the processes of charcoal incorporation and transportation, and the effects on soil organic matter are still not clear. In a long-term experimental burning site, we investigated the effects of slash-and-burn and determined soil organic carbon, charcoal carbon and nitrogen concentrations and the soil lightness of colour (L*) in the topmost soil material (0-1, 1-2.5 and 2.5-5 cm depths) before, immediately after the fire and one year after burning. The main results are that (i) only few charcoal particles from the forest floor were incorporated into the soil matrix by soil mixing animals. In 0-1 cm and during one year, the charcoal C concentrations increased only by 0.4 g kg-1 and the proportion of charcoal C to SOC concentrations increased from 2.8 to 3.4%; (ii) the SOC concentrations did not show any significant differences; (iii) soil lightness significantly decreased in the topmost soil layer and correlated with the concentrations of charcoal C (r=-0.87**) and SOC (r=-0.94**) in samples 0-5 cm. We concluded that the soil colour depends on the proportion of aromatic charcoal carbon in total organic matter and that Holocene burning could have influenced soil charcoal concentrations and soil colour.

  7. Effect of a catalyst on the kinetics of reduction of celestite (SrSO{sub 4}) by active charcoal

    SciTech Connect

    Sonawane, R.S.; Kale, B.B.; Apte, S.K.; Dongare, M.K.

    2000-02-01

    Reduction of celestite (SrSO{sub 4}) powder with particles of active charcoal has been studied extensively in the absence and presence of catalysts. The optimum temperature at the charging zone has been optimized to get a maximum water-soluble strontium sulfide value. The strontium value has been analyzed using a chemical method, which was verified by the instrumental method using an inductively coupled plasma-optical emission spectrophotometer (ICP-OES). The conversion-time data have been analyzed by using a modified volume-reaction (MVR) model, and the effect of the catalyst on kinetic parameters has been elucidated. It was found that potassium carbonate, potassium dichromate, sodium carbonate, and sodium dichromate catalysts were found to enhance the reaction rate quite satisfactorily in the reduction of the celestite (SrSO{sub 4}).

  8. Determining the sizes of micropores in activated charcoals by the pulsed NMR method

    NASA Astrophysics Data System (ADS)

    Gogelashvili, G. Sh.; Khozina, E. V.; Vartapetyan, R. Sh.; Ladychuk, D. V.; Grunin, Yu. B.

    2011-07-01

    The pulsed NMR method was used to measure the nuclear spin-spin relaxation of protons of water adsorbed in micropores of activated charcoal (AC) samples with different porous structures. A correlation was found between the spin-spin relaxation time of water protons in AC with completely filled micropores and the volume density of water primary adsorption centers in the AC samples. An equation for approximating obtained dependences is proposed that allows us to determine the volume of micropores in AC.

  9. Adsorption of H2, Ne, and N2 on Activated Charcoal

    NASA Technical Reports Server (NTRS)

    Chang, C. K.; Tward, E.; Boudaie, K. I.

    1986-01-01

    9-page report presents measured adsorption isotherms of hydrogen, neon, and nitrogen on activated charcoal for temperatures from 77 to 400 K and pressures from 1 to 80 atmospheres (0.1 to 8.1 MPa). Heats of adsorption calculated from isotherms also presented. Report gives expressions, based on ideal-gas law, which show relationship between different definitions of volume of gas adsorbed and used in describing low-pressure isotherms.

  10. Intake of honey mesquite (Prosopis glandulosa) leaves by lambs using different levels of activated charcoal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 24-day feeding trial was conducted to assess the effect of feeding four levels of activated charcoal (0.0, 0.33, 0.67 and 1.00 g/kg of body weight) on intake of honey mesquite leaves (Prosopis glandulosa Torr.) by 20 wether lambs (36.6 ± 0.6 kg) that were randomly assigned to treatments. Lambs wer...

  11. Activated Charcoal Does Not Reduce Duration of Phenytoin Toxicity in Hospitalized Patients.

    PubMed

    Cumpston, Kirk; Stromberg, Paul; Wills, Brandon K; Rose, S Rutherfoord

    2016-01-01

    Phenytoin toxicity frequently results in a prolonged inpatient admission. Several publications avow multidose activated charcoal (MDAC) will enhance the elimination of phenytoin. However, these claims are not consistent, and the mechanism of enhanced eliminaiton is unproven. The aim of this investigation is to compare the time to reach a clinical composite end point in phenytoin overdose patients treated with no activated charcoal (NoAC), single-dose activated charcoal (SDAC), and MDAC. This was a retrospective study using electronic poison center data. Patients treated in a health care facility with phenytoin concentrations >20 mg/L were included. Patients were grouped by use of SDAC, MDAC, and NoAC. The primary end points were either time to resolution of symptoms, hospital discharge, or the case was closed by a toxicologist. After applying inclusion and exclusion criteria, 132 cases were included for analysis. There were 88 NoAC, 13 SDAC, and 31 MDAC cases. The groups were similar in symptomatology, age, and chronicity of expsoure. Mean peak phenytoin concentrations (SD) were 42 mg/L (12), 41 mg/L (11), and 42 mg/L (11) for NoAC, SDAC, and MDAC, respectively. Mean time to reach the study end point was 39 hours [95% confidence interval (CI), 31-48], 52 hours (95% CI, 36-68), and 60 hours (95% CI, 45-75) for NoAC, SDAC, and MDAC, respectively. The groups appeared similar with respect to peak phenytoin concentrations and prevalence of signs and symptoms. In this observational series, the use of activated charcoal was associated with increased time to reach the composite end point of clinical improvement.

  12. Liquid phase adsorption behavior of inulin-type fructan onto activated charcoal.

    PubMed

    Li, Kecheng; Liu, Song; Xing, Ronge; Yu, Huahua; Qin, Yukun; Li, Pengcheng

    2015-05-20

    This study describes liquid phase adsorption characteristics of inulin-type fructan onto activated charcoal. Batch mode experiments were conducted to study the effects of pH, contact time, temperature and initial concentration of inulin. Nearly neutral solution (pH 6-8) was favorable to the adsorption and the equilibrium was attained after 40 min with the maximum adsorption Qmax 0.182 g/g (adsorbate/adsorbent) at 298 K. The experimental data analysis indicated that the adsorption process fitted well with the pseudo-second-order kinetic model (R(2) = 1) and Langmuir isotherms model (R(2) > 0.99). Thermodynamic parameters revealed that the adsorption process was spontaneous and exothermic with a physical nature. Inulin desorption could reach 95.9% using 50% ethanol solution and activated charcoal could be reused without significant losses in adsorption capacity. These results are of practical significance for the application of activated charcoal in the production and purification of inulin-type fructan.

  13. Antifungal activity of nano and micro charcoal particle polymers against Paecilomyces variotii, Trichoderma virens and Chaetomium globosum.

    PubMed

    Yang, Hee Jin; Cha, Yun Jeong; Kim, Hern; Choi, Shin Sik

    2016-01-25

    This study investigates the antifungal activity of a polymer integrated with nano-porous charcoal particles against Paecilomyces variotii, Chaetomium globosum, Trichoderma virens, which are all filamentous fungi. The charcoal polymers were prepared by combining charcoal powders with plastic resin under a vacuum to form charcoal particle protrusions on the polymer surface. The mycelial growth of P. variotii and T. virens exhibited a reduction of 10 and 30%, respectively, after the conidia were pre-treated with charcoal polymers, and in particular, no mycelial growth was found in C. globosum during 5 days of culture. The adsorption of Ca(2+) into charcoal was suggested to inhibit growth due to the reduction in the flux of calcium ions (Ca(2+)) into the hyphae. In 5 h, about 15 mM of Ca(2+) were removed from CaCl2 solution with 0.2 g/mL of polymers, and the nano-sized pores of the charcoals on the polymer were responsible for the Ca(2+) adsorption.

  14. Aminocyclopyrachlor sorption in biochar and activated charcoal amended soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aminocyclopyrachlor is a new herbicide active ingredient, classified as a member of the new chemical class “pyrimidine carboxylic acids”. It is used for control of broadleaf weeds and brush on non-cropland. Due to its potential mobility in some soils, there is interest in whether aminocyclopyrachlor...

  15. Determination of the Impregnant Concentrations on ASC Type Charcoal. A Magnetic Susceptibility Study

    DTIC Science & Technology

    1987-10-01

    chloropicrin etc., before and after adsorption on the diamagnetic charcoal prepared from coconut shell . However, the conclusions drawn from these... activation analysis for 55 elements was performed on two charcoal samples, namely the BPL and the CAL-1048, both supplied directly from Calgon Carbon ...of Neutron Activation Analysis on the BPL- Charcoal (Coal-Based, No Impregnants)................2424 TABLE B-2: Result of Neutron Activation Analysis

  16. Minor changes in soil organic carbon and charcoal concentrations detected in a temperate deciduous forest a year after an experimental slash-and-burn

    NASA Astrophysics Data System (ADS)

    Eckmeier, E.; Gerlach, R.; Skjemstad, J. O.; Ehrmann, O.; Schmidt, M. W. I.

    2007-06-01

    Anthropogenic fires affected the temperate deciduous forests of Central Europe over millennia. Biomass burning releases carbon to the atmosphere and produces charcoal, which potentially contributes to the stable soil carbon pools and is an important archive of environmental history. The fate of charcoal in soils of temperate deciduous forests, i.e. the processes of charcoal incorporation and transportation and the effects on soil organic matter are still not clear. We investigated the effects of slash-and-burn at a long-term experimental burning site and determined soil organic carbon and charcoal carbon concentrations as well as the soil lightness of colour (L*) in the topmost soil material (0-1, 1-2.5 and 2.5-5 cm depths) before, immediately after the fire and one year later. The main results are that (i) only a few of the charcoal particles from the forest floor were incorporated into the soil matrix, presumably by soil mixing animals. In the 0-1 cm layer, during one year, the charcoal C concentration increased only by 0.4 g kg-1 and the proportion of charcoal C to SOC concentration increased from 2.8 to 3.4%; (ii) the SOC concentrations did not show any significant differences; (iii) soil lightness decreased significantly in the topmost soil layer and correlated well with the concentrations of charcoal C (r=-0.87**) and SOC (r=-0.94**) in the samples from the 0-5 cm layer. We concluded that Holocene biomass burning could have influenced soil charcoal concentrations and soil colour.

  17. Research report: Charcoal type used for hookah smoking influences CO production.

    PubMed

    Medford, Marlon A; Gasier, Heath G; Hexdall, Eric; Moffat, Andrew D; Freiberger, John J; Moon, Richard E

    2015-01-01

    A hookah smoker who was treated for severe carbon monoxide poisoning with hyperbaric oxygen reported using a different type of charcoal prior to hospital admission, i.e., quick-light charcoal. This finding led to a study aimed at determining whether CO production differs between charcoals commonly used for hookah smoking, natural and quick-light. Our hypothesis was that quick-light charcoal produces significantly more CO than natural charcoal. A medium-sized hookah, activated charcoal filter, calibrated syringe, CO gas analyzer and infrared thermometer were assembled in series. A single 9-10 g briquette of either natural or quick-light charcoal was placed atop the hookah bowl and ignited. CO output (ppm) and temperature (degrees C) were measured in three-minute intervals over 90 minutes. The mean CO levels produced by quick-light charcoal over 90 minutes was significantly higher (3728 ± 2028) compared to natural charcoal (1730 ± 501 ppm, p = 0.016). However, the temperature was significantly greater when burning natural charcoal (292 ± 87) compared to quick-light charcoal (247 ± 92 degrees C, p = 0.013). The high levels of CO produced when using quick-light charcoals may be contributing to the increase in reported hospital admissions for severe CO poisoning.

  18. Use of Activated Charcoal for {sup 220}Rn Adsorption for Operations Associated with the Uranium Deposit in the Auxiliary Charcoal Bed at the Molten Salt Reactor Experiment Facility

    SciTech Connect

    Coleman, R.L.

    1999-03-01

    Measurements have been collected with the purpose of evaluating the effectiveness of activated charcoal for the removal of {sup 220}Rn from process off-gas at the Molten Salt Reactor Experiment (MSRE) at Oak Ridge National Laboratory. A series of bench-scale tests were performed at superficial flow velocities of 10, 18, 24, and 33 cm/s (20, 35, 47, and 65 ft/min) with a continuous input concentration of {sup 220}Rn in the range of 9 x 10{sup 3} pCi/L. In addition, two tests were performed at the MSRE facility by flowing helium through the auxiliary charcoal bed uranium deposit. These tests were performed so that the adsorptive effectiveness could be evaluated with a relatively high concentration of {sup 220}Rn. In addition to measuring the effectiveness of activated charcoal as a {sup 220}Rn adsorption media, the source term for available {sup 220}Rn in the deposit is actually available for removal and that the relative activity of fission gases is very small when compared to {sup 220}Rn. The measurement data were then used to evaluate the expected effectiveness of a proposed charcoal adsorption bed consisting of a right circular cylinder having a diameter of 43 cm and a length of 91 cm (17 in. I.D. x 3 ft.). The majority of the measurement data predicts an overall 220Rn activity reduction factor of about 1 x 10{sup 9} for such a design; however, two measurements collected at a flow velocity of 18 cm/s (35 ft/min) indicated that the reduction factor could be as low as 1 x 10{sup 6}. The adsorptive capacity of the proposed trap was also evaluated to determine the expected life prior to degradation of performance. Taking a conservative vantage point during analysis, it was estimated that the adsorption effectiveness should not begin to deteriorate until a {sup 220}Rn activity on the order of 10{sup 10} Ci has been processed. It was therefore concluded that degradation of performance would likely occur as the result of causes other than filling by radon progeny.

  19. Use of Activated Charcoal for Rn-220 Adsorption for Operations Associated with the Uranium Deposit in the Auxiliary Charcoal Bed at the Molten Salt Reactor Experiment Facility

    SciTech Connect

    Coleman, R.L.

    1999-03-17

    Measurements have been collected with the purpose of evaluating the effectiveness of activated charcoal for the removal of {sup 220}Rn from process off-gas at the Molten Salt Reactor Experiment (MSRE) at Oak Ridge National Laboratory. A series of bench-scale tests were performed at superficial flow velocities of 10, 18, 24, and 33 cm s{sup -1} (20, 35, 47, and 65 ft min{sup -1}) with a continuous input concentration of {sup 220}Rn in the range of 9 x 10{sup 3} pCi L{sup -1}. In addition, two tests were performed at the MSRE facility by flowing helium through the auxiliary charcoal bed uranium deposit. These tests were performed so that the adsorptive effectiveness could be evaluated with a relatively high concentration of {sup 220}Rn. In addition to measuring the effectiveness of activated charcoal as a {sup 220}Rn adsorption media, the source term for available {sup 220}Rn and gaseous fission products was evaluated and compared to what is believed to be present in the deposit. The results indicate that only a few percent of the total {sup 220}Rn in the deposit is actually available for removal and that the relative activity of fission gases is very small when compared to {sup 220}Rn. The measurement data were then used to evaluate the expected effectiveness of a proposed charcoal adsorption bed consisting of a right circular cylinder having a diameter of 43 cm and a length of 91 cm (17 in. I.D. x 3 ft.). The majority of the measurement data predicts an overall {sup 220}Rn activity reduction factor of about 1 x 10{sup 9} for such a design; however, two measurements collected at a flow velocity of 18 cm s{sup -1} (35 ft min{sup -1}) indicated that the reduction factor could be as low as 1 x 10{sup 6}. The adsorptive capacity of the proposed trap was also evaluated to determine the expected life prior to degradation of performance. Taking a conservative vantage point during analysis, it was estimated that the adsorption effectiveness should not begin to deteriorate

  20. Forensic aspects of carbon monoxide poisoning by charcoal burning in Denmark, 2008-2012: an autopsy based study.

    PubMed

    Nielsen, Pia Rude; Gheorghe, Alexandra; Lynnerup, Niels

    2014-09-01

    Carbon monoxide (CO) inhalation is a well-known method of committing suicide. There has been a drastic increase in suicide by inhalation of CO, produced from burning charcoal, in some parts of Asia, and a few studies have reported an increased number of these deaths in Europe. CO-related deaths caused by charcoal burning have, to our knowledge, not been recorded in the Danish population before. In this retrospective study we present all autopsied cases of CO poisoning caused by charcoal burning in the period 2008-2012. 19 autopsied cases were identified, comprising 11 suicides, 4 accidents, and 2 cases of maternal/paternal filicide-suicide. The mean age of decedents was 38.2 years and the majority of the decedents were men. In 16 cases carboxyhemoglobin levels were above 50 % and in 14 cases we found distinctive cherry red livor mortis. Various concentrations of ethanol and drugs were found in 9 cases. Data suggest that this method of death has increased significantly in Denmark. Therefore, it is highly relevant to draw attention to the subject, to increase awareness as well as prevent future escalation.

  1. Efficiency of membrane technology, activated charcoal, and a micelle-clay complex for removal of the acidic pharmaceutical mefenamic acid.

    PubMed

    Khalaf, Samer; Al-Rimawi, Fuad; Khamis, Mustafa; Nir, Shlomo; Bufo, Sabino A; Scrano, Laura; Mecca, Gennaro; Karaman, Rafik

    2013-01-01

    The efficiency of sequential advanced membrane technology wastewater treatment plant towards removal of a widely used non-steroid anti-inflammatory drug (NSAID) mefenamic acid was investigated. The sequential system included activated sludge, ultrafiltration by hollow fibre membranes with 100 kDa cutoff, and spiral wound membranes with 20 kDa cutoff, activated carbon and a reverse osmosis (RO) unit. The performance of the integrated plant showed complete removal of mefenamic acid from spiked wastewater samples. The activated carbon column was the most effective component in removing mefenamic acid with a removal efficiency of 97.2%. Stability study of mefenamic acid in pure water and Al-Quds activated sludge revealed that the anti-inflammatory drug was resistant to degradation in both environments. Batch adsorption of mefenamic acid by activated charcoal and a composite micelle (otadecyltrimethylammonium (ODTMA)-clay (montmorillonite) was determined at 25.0°C. Langmuir isotherm was found to fit the data with Qmax of 90.9 mg g(-1) and 100.0 mg g(-1) for activated carbon and micelle-clay complex, respectively. Filtration experiment by micelle-clay columns mixed with sand in the mg L(-1) range revealed complete removal of the drug with much larger capacity than activated carbon column. The combined results demonstrated that an integration of a micelle-clay column in the plant system has a good potential to improve the removal efficiency of the plant towards NSAID drugs such as mefenamic acid.

  2. Evaluation of radon adsorption characteristics of a coconut shell-based activated charcoal system for radon and thoron removal applications.

    PubMed

    Karunakara, N; Sudeep Kumara, K; Yashodhara, I; Sahoo, B K; Gaware, J J; Sapra, B K; Mayya, Y S

    2015-04-01

    Radon ((222)Rn), thoron ((220)Rn), and their decay products contribute a major fraction (more than 50%) of doses received from ionisation radiation in public domain indoor environments and occupation environments such as uranium mines, thorium plants, and underground facilities, and are recognised as important radiological hazardous materials, which need to be controlled. This paper presents studies on the removal of (222)Rn and (220)Rn from air using coconut shell-based granular activated charcoal cylindrical adsorber beds. Experiments were conducted to evaluate the (222)Rn and (220)Rn adsorption characteristics, and the mitigation efficiency of coconut-based activated charcoal available in India. The performance parameters evaluated include breakthrough time (τ) and adsorption coefficient (K), and degassing characteristics of the charcoal bed of varying dimensions at different flow rates. While the breakthrough for (222)Rn occurred depending on the dimension of the adsorber bed and flow rates, for (220)Rn, the breakthrough did not occur. The breakthrough curve exhibited a stretched S-shape response, instead of the theoretically predicted sharp step function. The experiments confirm that the breakthrough time individually satisfies the quadratic relationship with respect to the diameter of the bed, and the linear relationship with respect to the length, as predicted in the theory. The K value varied in the range of 2.3-4.12 m(3) kg(-1) with a mean value of 2.99 m(3) kg(-1). The K value was found to increase with the increase in flow rate. Heating the charcoal to ∼ 100 °C resulted in degassing of the adsorbed (222)Rn, and the K of the degassed charcoal and virgin charcoal were found to be similar with no deterioration in performance indicating the re-usability of the charcoal.

  3. Lead Induced Hepato-renal Damage in Male Albino Rats and Effects of Activated Charcoal

    PubMed Central

    Offor, Samuel J.; Mbagwu, Herbert O. C.; Orisakwe, Orish E.

    2017-01-01

    Lead is a multi-organ toxicant implicated in various cancers, diseases of the hepatic, renal, and reproductive systems etc. In search of cheap and readily available antidote this study has investigated the role of activated charcoal in chronic lead exposure in albino rats. Eighteen mature male albino rats were used, divided into three groups of six rats per group. Group 1 (control rats) received deionised water (10 ml/kg), group 2 was given lead acetate solution 60 mg/kg and group 3 rats were given lead acetate (60 mg/kg) followed by Activated charcoal, AC (1000 mg/kg) by oral gavage daily for 28 days. Rats in group 2 showed significant increases in serum Aspartate aminotransferase, Alkaline phosphatase, Alanine aminotransferase, urea, bilirubin, total cholesterol, triglycerides, Low Density Lipoprotein, Very Low Density Lipoproteins, Total White Blood Cell Counts, Malondialdehyde, Interleukin-6, and decreases in Packed Cell Volume, hemoglobin concentration, Red blood cell count, total proteins, albumins, superoxide dismutase, glutathione peroxidase and total glutathione. Co-administration of AC significantly decreased these biomarkers with the exception of the sperm parameters. Histopathology of liver and kidney also confirmed the protective effective of AC against lead induced hepato-renal damage. AC may be beneficial in chronic lead induced liver and kidney damage. PMID:28352230

  4. [Possible release of aluminum from activated charcoal filters used in home hemodialysis].

    PubMed

    Jourdan, J L; Maingourd, C; Meguin, C; Nivet, H; Martin, C; Moulier, M C

    1986-01-01

    In 1984, 38 sera from home hemodialysis patients were found with a significant increase of aluminum (Al) from 67.8 +/- 44.3 to 102.0 +/- 45.9 micrograms/l (p less than 0.001) compared to 1983. The only change was an activated charcoal (AC) filter in the water treatment circuit, added downstream of the water softener. Five different home hemodialysis AC filters were tested: Microclean CA Dia Cuno, Traitement Standard des Eaux (TSE)R, Permo, C2R, Gambro. AC was shown to be the main source of Al, its content ranging from 1251 +/- 116 to 7569 +/- 969 mg/kg. Al released in 2000 l of liter rinsing water varied from 1.6 +/- 1.3 to 41.3 +/- 5.5 mg. (mean concentration: 0.8 to 20.6 micrograms/l): Gambro less than or equal to C2R less than TSE less than Permo less than Cuno (p less than 0.01). Al loading of charcoal could occur either before or during the activation process, by contaminated water, other added substances, or during packaging. In conclusion, our study suggests, first, to put AC filters upstream of Al captor to avoid Al intoxication, second, to systematically dose Al and may be other metallic substances in every manufactured AC sold for therapeutic purpose.

  5. The effect of activated charcoal on adenine-induced chronic renal failure in rats.

    PubMed

    Ali, Badreldin H; Alza'abi, Mohamed; Ramkumar, Aishwarya; Al-Lawati, Intisar; Waly, Mostafa I; Beegam, Sumaya; Nemmar, Abderrahim; Brand, Susanne; Schupp, Nicole

    2014-03-01

    Activated charcoal (AC) is a sorbent that has been shown to remove urinary toxins like urea and indoxyl sulfate. Here, the influence of AC on kidney function of rats with experimental chronic renal failure (CRF) is investigated. CRF was induced in rats by feeding adenine (0.75%) for four weeks. As an intervention, AC was added to the feed at concentrations of 10%, 15% or 20%. Adenine treatment impaired kidney function: it lowered creatinine clearance and increased plasma concentrations of creatinine, urea, neutrophil gelatinase-associated lipocalin and vanin-1. Furthermore, it raised plasma concentrations of the uremic toxins indoxyl sulfate, phosphate and uric acid. Renal morphology was severely damaged and histopathological markers of inflammation and fibrosis were especially increased. In renal homogenates, antioxidant indices, including superoxide dismutase and catalase activity, total antioxidant capacity and reduced glutathione were adversely affected. Most of these changes were significantly ameliorated by dietary administration of AC at a concentration of 20%, while effects induced by lower doses of dietary AC on adenine nephrotoxicity were not statistically significant. The results suggest that charcoal is a useful sorbent agent in dietary adenine-induced CRF in rats and that its usability as a nephroprotective agent in human kidney disease should be studied.

  6. Oral iodinated activated charcoal improves lung function in patients with COPD.

    PubMed

    Skogvall, Staffan; Erjefält, Jonas S; Olin, Anders I; Ankerst, Jaro; Bjermer, Leif

    2014-06-01

    The effect of 8 weeks treatment with oral iodinated activated charcoal (IAC) on lung function of patients with moderate chronic obstructive pulmonary disease (COPD) was examined in a double blind randomized placebo controlled parallel group study with 40 patients. In the IAC group, patients showed a statistically significant improvement of FEV1 baseline by 130 ml compared to placebo, corresponding to 8.2% improvement (p = 0.031*). Correlation statistics revealed that the improvement of FEV1 baseline was significantly correlated both to FEV1 post-bronchodilator (p = 0.0020**) and FEV1 post-exercise (0.033*) values. This demonstrates that the improved baseline lung function by IAC did not inhibit a further beta2-adrenoceptor relaxation, and thus that patients did not reach a limit for maximal improvement of the lung function after IAC treatment. Eight patients in the IAC group developed abnormal thyroid hormone levels transiently during the treatment. This side effect was not correlated to improvement of lung function (p = 0.82). No serious adverse effects directly related to the treatment were recorded. In summary, this study demonstrates that iodinated activated charcoal surprisingly and significantly improved lung function of patients with moderate COPD. The underlying mechanism of action is unclear, but is likely to be different from the drugs used today. The immediate conclusion is that further studies are now justified in order to determine clinical efficacy of IAC in COPD and explore possible mechanisms of action.

  7. In vitro adsorption of sodium pentobarbital by SuperChar, USP and Darco G-60 activated charcoals

    SciTech Connect

    Curd-Sneed, C.D.; Parks, K.S.; Bordelon, J.G.; Stewart, J.J.

    1987-01-01

    This study was designed to examine the in vitro adsorption of sodium pentobarbital by three activated charcoals. Solutions of sodium pentobarbital (20 mM) were prepared in distilled water and in 70% sorbitol (w/v). Radiolabeled (/sup 14/C) sodium pentobarbital was added to each solution to serve as a concentration marker. Two ml of each drug solution was added to test tubes containing 40 mg of either Darco G-60, USP, or SuperChar activated charcoal. The drug-charcoal mixtures were incubated at 37 degrees C for O, 2.5, 5, 7.5 or 10 min. Equilibrium, indicated by a constant percentage of drug bound for two consecutive time periods, was established immediately for the aqueous mixtures and for Darco G-60 in sorbitol. The time to equilibrium was prolonged for USP (2.5 min) and SuperChar (5 min) in the presence of sorbitol. In the second series of experiments, solutions of sodium pentobarbital (1.25 to 160 mM) were prepared in either distilled water or sorbitol. Amount of drug bound by 10 to 320 mg of activated charcoal within a 10 min incubation period was determined. Scatchard analysis determined maximum binding capacity (Bmax) and dissociation constants (Kd) for each activated charcoal. In water, Bmax (mumoles/gm) was greatest for SuperChar (1141), followed by USP (580) and Darco G-60 (381), while the Kd's did not differ. Sorbitol did not change the Bmax or Kd of USP or Darco G-60, but the additive significantly decreased the Bmax (717) and increased the Kd for SuperChar (3.3 to 10.1 mM). The results suggest that relative binding capacity of activated charcoal is directly proportional to surface area, and that sorbitol significantly reduces sodium pentobarbital binding to SuperChar.

  8. Effects of the dietary supplements, activated charcoal and copper chlorophyllin, on urinary excretion of trimethylamine in Japanese trimethylaminuria patients.

    PubMed

    Yamazaki, Hiroshi; Fujieda, Masaki; Togashi, Masahiro; Saito, Tetsuya; Preti, George; Cashman, John R; Kamataki, Tetsuya

    2004-04-16

    Trimethylaminuria (TMAU) is a metabolic disorder characterized by the inability to oxidize and convert dietary-derived trimethylamine (TMA) to trimethylamine N-oxide (TMAO). This disorder has been relatively well-documented in European and North American populations, but no reports have appeared regarding patients in Japan. We identified seven Japanese individuals that showed a low metabolic capacity to convert TMA to its odorless metabolite, TMAO. The metabolic capacity, as defined by the concentration of TMAO excreted in the urine divided by TMA concentration plus TMAO concentration, in these seven individuals ranged from 70 to 90%. In contrast, there were no healthy controls examined with less than 95% of the metabolic capacity to convert TMA to TMAO. The intake of dietary charcoal (total 1.5 g charcoal per day for 10 days) reduced the urinary free TMA concentration and increased the concentration of TMAO to normal values during charcoal administration. Copper chlorophyllin (total 180 mg per day for 3 weeks) was also effective at reducing free urinary TMA concentration and increasing TMAO to those of concentrations present in normal individuals. In the TMAU subjects examined, the effects of copper chlorophyllin appeared to last longer (i.e., several weeks) than those observed for activated charcoal. The results suggest that the daily intake of charcoal and/or copper chlorophyllin may be of significant use in improving the quality of life of individuals suffering from TMAU.

  9. Kinetics studies of d-glucose hydrogenation over activated charcoal supported platinum catalyst

    NASA Astrophysics Data System (ADS)

    Ahmed, Muthanna J.

    2012-02-01

    The kinetics of the catalytic hydrogenation of d-glucose to produce d-sorbitol was studied in a three-phase laboratory scale reactor. The hydrogenation reactions were performed on activated charcoal supported platinum catalyst in the temperature range 25-65°C and in a constant pressure of 1 atm. The kinetic data were modeled by zero, first and second-order reaction equations. In the operating regimes studied, the results show that the hydrogenation reaction was of a first order with respect to d-glucose concentration. Also the activation energy of the reaction was determined, and found to be 12.33 kJ mole-1. A set of experiment was carried out to test the deactivation of the catalyst, and the results show that the deactivation is slow with the ability of using the catalyst for several times with a small decrease in product yield.

  10. Holocene Vegetation and Climate Shifts from Sutherland Fen, Black Rock Forest, New York - Plant Macrofossils, Charcoal, and Carbon

    NASA Astrophysics Data System (ADS)

    Peteet, D. M.; Guilderson, T.

    2008-12-01

    Sutherland Fen formed about 12,600 C-14 years ago (15,000 calendar years), the same time as adjacent Sutherland Pond and regional deglaciation. High-resolution (2 cm) analysis of the 3.2 m fen core indicates three major macrofossils zones indicative of climate shifts. These climate shifts were defined over fifty years ago through pollen stratigraphy of the regional northeastern US, but macrofossils provide new details concerning hydrological and ecological shifts. The lowest (SUB-1) dated to the late-glacial, is indicative of a shallow pond characterized by Najas, Nuphar, and Potamogeton seeds and containing Salix (willow) buds, a Rubus (berry) seed, and Picea glauca (white spruce) needles and sterigmata from the surrounding upland. Sedimention rates are highest in this boreal environmental zone. The overlying zone (SUB-2) beginning at 11,500 years ago (Holocene) indicates a continuing pond environment with aquatics such as Najas, Nuphar, and Brasenia, but Picea disappears and Pinus strobus (white pine) dominates the lower section of the zone. A warmer, drier climate produces sustained charcoal in the record at the Holocene boundary. Pinus strobus needles and seeds subsequently disappear and are replaced from 9000 to 7500 years ago by Pinus rigida (pitch pine), Betula populifolia/papyrifera (grey/paper birch), and emergent wetland plants such as Decodon, Cladium, and Cephalanthus, as well as Dulichium, Eleocharis, and Carex, suggesting a shallowing pond and a drier climate. Chara oospores indicate probably groundwater influx into the fen. About 4000 years ago, charcoal again is present. In the subsequent late Holocene a more acidic, moist, fen environment is characterized by Sphagnum, Rubus, Hypericum, Viola, Chamaedaphne, and Carex, though Brasenia and Potamogeton (pond indicators) are occasionally present. The continued presence of Sphagnum led to high carbon accumulation because of less decomposition. This increase in Sphagnum in recent millennia with aquatics

  11. Radon Adsorbed in Activated Charcoal--A Simple and Safe Radiation Source for Teaching Practical Radioactivity in Schools and Colleges

    ERIC Educational Resources Information Center

    Al-Azmi, Darwish; Mustapha, Amidu O.; Karunakara, N.

    2012-01-01

    Simple procedures for teaching practical radioactivity are presented in a way that attracts students' attention and does not make them apprehensive about their safety. The radiation source is derived from the natural environment. It is based on the radioactivity of radon, a ubiquitous inert gas, and the adsorptive property of activated charcoal.…

  12. Effects of scorched food leachates with or without activated charcoal pretreatment on AhR activation in cultured cells.

    PubMed

    Takahashi, Satoshi; Morita, Koji; Kinoshita, Makoto; Fujimori, Shin; Ishikawa, Toshio

    2015-12-01

    Aryl hydrocarbon receptor (AhR) is a transcription factor activated by xenobiotics, including dioxins and polycyclic aromatic hydrocarbons (PAHs). Although AhR is also activated by some dietary constituents, it has not been completely clarified in what circumstances AhR ligands are ingested in our daily life. Because PAHs are formed by the incomplete combustion of organic materials, we hypothesized that scorched foods might contain and leach out AhR ligands sufficient to stimulate AhR in vitro. To test this hypothesis, scorched foods (bread, cheese, etc.) were mixed vigorously with water, and the supernatants were retrieved as samples. The samples were added to HepG2 cells stably expressing an AhR-responsive reporter gene. Also, expression of CYP1A1, an endogenous AhR-responsive gene, was analyzed by RT-PCR in different cell lines treated with the samples. We further tested whether pretreatment of the samples with activated charcoal would alter their AhR-stimulating activity. All the supernatant samples tested induced AhR-dependent reporter gene activity and CYP1A1 mRNA expression. In some samples, these inductions were inhibited by pretreatment with activated charcoal. Our findings indicate that scorched food leachates stimulate AhR in cultured cells and that activated charcoal adsorbs the AhR-stimulating substances in some leachates. Thus, people who habitually eat scorched foods are exposed to AhR ligands on a regular basis. Further studies are needed to elucidate whether burnt foods actually exert biological effects on our health.

  13. The Reaction of Oxygen-Nitrogen Mixtures with Granular Activated Carbons Below the Spontaneous Ignition Temperature.

    DTIC Science & Technology

    1983-01-14

    number) Activated carbon Oxidation of charcoals with 02 Spontaneous ignition temperature Anonialous desorption of CO and CO2 20. VTRACT (Conlnue on...that desorbed as CO or CO2. An example of the temperature control is shown (Figure 7) for the coconut shell charcoal (G-210) in 100% oxygen in which...and Flammability 2, 141-156 (1971). (5) "Standard Test for Ignition Temperature of Granular Activated Carbon ’’, American Society of Testing Materials

  14. Study of Single Catalytic Events at Copper-in-Charcoal: Localization of Click Activity Through Subdiffraction Observation of Single Catalytic Events.

    PubMed

    Decan, Matthew R; Scaiano, Juan C

    2015-10-15

    Single molecule fluorescence microscopy reveals that copper-in-charcoal--a high performance click catalyst- has remarkably few catalytic sites, with 90% of the charcoal particles being inactive, and for the catalytic ones the active sites represent a minute fraction (∼0.003%) of the surface. The intermittent nature of the catalytic events enables subdiffraction resolution and mapping of the catalytic sites.

  15. Feasibility of prehospital treatment with activated charcoal: Who could we treat, who should we treat?

    PubMed Central

    Isbister, G; Dawson, A; Whyte, I

    2003-01-01

    Methods: Review of deliberate self poisoning presentations to the emergency department (ED) of a toxicology unit by ambulance over six years. Data were extracted from a standardised prospective database of poisonings. Outcomes included: number of patients attended by ambulance and number arriving in emergency within one hour. Cases were stratified by ingestion type, based on toxicity and sedative activity. Results: 2041 poisoning admissions were included. The median time to ambulance attendance was 1 h 23 min (IQR 37 min–3 h) and to hospital attendance was 2 h 15 min (IQR 1 h 25 min–4 h). In 774 cases (38%) ambulance attendance occurred within one hour, but in only 161 (8%) did ED attendance occur within one hour. Non-sedating, highly toxic substances were ingested in 55 cases, 24 (23 with GCS>14) with ambulance attendance, and five with ED attendance, within one hour. Conversely 439 patients ingested a less toxic, sedative agent, 160 with ambulance attendance, and 32 with ED attendance, within one hour. Limiting decontamination to patients ingesting highly toxic, non-sedating compounds (GCS<14) reduces the proportion requiring treatment to 23 of the 774 (3.0%), an additional 18 patients. Conclusion: More patients could potentially be decontaminated if all patients attended by ambulance within one hour received charcoal. However, this would expose 128 patients with sedative, low risk poisonings to the risk of aspiration, and only treat 18 extra high risk poisonings. This small potential benefit of prehospital charcoal is unlikely to justify the expense in training and protocols required to implement it PMID:12835364

  16. Commercial charcoal manufacture in Brazil

    SciTech Connect

    Rezende, M.E.; Lessa, A.; Pasa, V.; Sampaio, R.; Macedo, P.

    1993-12-31

    Brazil is the only country where charcoal has a major industrial us. Almost 40% of the pig iron and all the ferroalloys produced in the country are based on it and were established near Minas Gerais iron ore deposits using non-sustainable farm charcoal. Since the 1980s charcoal production from large eucalyptus forests is gradually increasing, accounting for 40% of the 8 million tonnes produced in 1991. Farm charcoal is produced when native forests are slashed to give way to farm land. Adequate techniques, labor rights or environmental concerns are not common in this scenario. In large eucalyptus forests charcoal production has a different business approach. Several kinds of masonry ovens are used in both scenarios. Continuous carbonization kilns are not feasible yet because of their high capital cost. The search for a new cheapest design or for the upgrading of the carbonization byproducts is a must. Promising results are shown. Plastics and fine chemicals were already obtained from wood tar. The first Brazilian pilot plant for wood tar fractionation will be started by 9/93. Ironworks have different profiles. Some plants are up-to-date integrated mini-steelworks. Others are small producers of pig ingots. They have in common the need to face coke ironmaking route. Brazilian exports of charcoal based iron and steel products have attained the goal until now. Future charcoal competitiveness will not be so easy. Although expertises believe that coke prices can not stand low for long time it poses additional difficulty to the Brazilian charcoal ironmaker. Three scenarios projected for the future of charcoal ironmaking show that as long as charcoal production costs are properly managed, charcoal will be competitive with coke. The authors defend a common research program that looks for technologies suited to the Brazilian reality.

  17. Study of variations in soil water potential with the incorporation of charcoal and carbon nanotubes through infrared thermal images

    NASA Astrophysics Data System (ADS)

    Villaseñor-Mora, Carlos; González-Vega, Arturo; Hernández, Víctor H.

    2016-09-01

    Different concentrations of charcoal and carbon nanotubes were incorporated in different mix types of soil samples, these were previously chemically characterized, and physically grain standardized, then the water potential was measured by traditional procedures, which need to consider the water composition and the soil salinity to achieve an accurate measurement, and by infrared thermal images where the water potential was correlated with the superficial emissivity. It was observed that the organic incorporation increases the water potential but it depends of soil gradation, a biggest increment of the water potential was observed in a poorly graded soil than that observed in a well graded soil; the nanotubes in low concentrations do not present considerable changes in the water potential, and in high concentrations the cost is not profitable. It was analyzed the minimum concentration changes of charcoal and nanotubes in the soil that can be measured with thermal emissivity, and the deepness at which the infrared thermal images can measure, also it was studied the rate of water drain in the different soils, and the ability of follow this with thermal sequence of images.

  18. Removal of NOx or its conversion into harmless gases by charcoals and composites of metal oxides

    SciTech Connect

    Ishihara, Shigehisa; Furutsuka, Takeshi

    1996-12-31

    In recent years, much attention has been devoted to environmental problems such as acid rain, photochemical smog and water pollution. In particular, NOx emissions from factories, auto mobiles, etc. in urban areas have become worse. To solve these problems on environmental pollution on a global scale, the use of activated charcoal to reduce air pollutants is increasing. However, the capability of wood-based charcoal materials is not yet fully known. The removal of NOx or its conversion into harmless gases such as N{sub 2} should be described. In this study, the adsorption of NO over wood charcoal or metal oxide-dispersed wood charcoal was investigated. In particular, carbonized wood powder of Sugi (Cryptomeria japonica D. Don) was used to study the effectivity of using these materials in adsorbing NOx. Since wood charcoal is chemically stable, metal oxide with the ability of photocatalysis was dispersed into wood charcoal to improve its adsorption and capability to use the light energy effectively.

  19. Does temperature of charcoal creation affect subsequent mineralization of soil carbon and nitrogen?

    NASA Astrophysics Data System (ADS)

    Pelletier-Bergeron, S.; Bradley, R.; Munson, A. D.

    2012-04-01

    Forest fire is the most common form of natural disturbance of boreal forest ecosystems and has primordial influence on successional processes. This may be due in part to the pre-disturbance vegetation development stage and species composition, but these successional pathways could also vary with differences in fire behavior and consequently in fire intensity, defined as the energy released during various phases of a fire. Fire intensity may also affect soil C and N cycling by affecting the quality of the charcoal that is produced. For example, the porosity of coal tends to increase with increasing temperature at which it is produced Higher porosity would logically increase the surface area to which dissolved soil molecules, such as tannins and other phenolics, may be adsorbed. We report on a microcosm study in which mineral and organic soils were jointly incubated for eight weeks with a full factorial array of treatments that included the addition of Kalmia tannins, protein, and wood charcoal produced at five different temperatures. A fourth experimental factor comprised the physical arrangement of the material (stratified vs. mixed), designed to simulate the effect of soil scarification after fire and salvage harvest. We examined the effects of these treatments on soil C and N mineralisation and soil microbial biomass. The furnace temperature at which the charcoal was produced had a significant effect on its physico-chemical properties; increasing furnace temperatures corresponded to a significant increase in % C (P<0.001), and a significant decrease in %O (P<0.001) and %H (P<0.001). Temperature also had significant impacts on microporosity (surface area and volume). Temperature of production had no effect (P=0.1355) on soil microbial biomass. We observed a linear decreasing trend (P<0.001) in qCO2 with increasing temperature of production, which was mainly reflected in a decline in basal respiration. Finally, we found a significant interaction (P=0.010) between

  20. Replacement of charcoal sorbent in the VOST

    SciTech Connect

    Johnson, L.D.; Fuerst, R.G.; Foster, A.L.; Bursey, J.T.

    1993-01-01

    EPA Method 0030, the Volatile Organic Sampling Train (VOST), for sampling volatile organics from stationary sources, specifies the use of petroleum-base charcoal in the second sorbent tube. Charcoal has proven to be a marginal performer as a sampling sorbent, partly due to inconsistency in analyte recovery. In addition, commercial availability of petroleum charcoal for VOST tubes has been variable. Lack of data on comparability and variability of charcoals for VOST application has created uncertainty when other charcoals are substituted. Five potential sorbent replacements for charcoal in Method 0030 were evaluated along with a reference charcoal. Two of the sorbents tested, Ambersorb XE-340 and Tenax GR, did not perform well enough to qualify as replacements. Three candidates, Anasorb 747, Carbosieve S-III and Kureha Beaded Activated Charcoal, performed adequately, and produced statistically equivalent results. Anasorb 747 appears to be an acceptable replacement for petroleum charcoal, based on a combination of performance, availability, and cost.

  1. Recovery of datable charcoal beneath young lavas: lessons from Hawaii.

    USGS Publications Warehouse

    Lockwood, J.P.; Lipman, P.W.

    1980-01-01

    Field studies in Hawaii aimed at providing a radiocarbon-based chronology of prehistoric eruptive activity have led to a good understanding of the processes that govern the formation and preservation of charcoal beneath basaltic lava flows. Charcoal formation is a rate-dependent process controlled primarily by temperature and duration of heating, as well as by moisture content, density, and size of original woody material. Charcoal will form wherever wood buried by lava is raised to sufficiently high temperatures, but owing to the availability of oxygen it is commonly burned to ash soon after formation. Wherever oxygen circulation is sufficiently restricted, charcoal will be preserved, but where atmospheric oxygen circulates freely, charcoal will only be preserved at a lower temperature, below that required for charcoal ignition or catalytic oxidation. These factors cause carbonized wood, especially that derived from living roots, to be commonly preserved beneath all parts of pahoehoe flows (where oxygen circulation is restricted), but only under margins of aa. Practical guidelines are given for the recovery of datable charcoal beneath pahoehoe and aa. Although based on Hawaiian basaltic flows, the guidelines should be applicable to other areas. -Authors

  2. The Effect of Humidity on the Collection Efficiency for Oxygenated Compounds Absorbed on Activated Charcoal

    DTIC Science & Technology

    1990-08-01

    Journal 43: 423-426 (1982). 6. Mantell, C. L.: Adsorption , pp. 2-161. McGraw-Hill Book Co., New York, (1951). 7. Smisek, M. and S. Cerny: Active Carbon ...Farris: The Effect of Moisture on the Adsorption of Chloroform by Activated Carbon . American Industrial Hygiene Association Journal. 46: 20-23, (1985...522-625 (1987). 20. Okazaki, M., H. Tamon, R. Toei: Prediction of Binary Adsorption Equilibria of Solvent and Water Vapor on Activated Carbon . Journal

  3. Chronic exposure to carbon monoxide in two elderly patients using a kotatsu, a traditional Japanese charcoal-based heater.

    PubMed

    Nakamura, Toshinori; Setsu, Koutaro; Takahashi, Tohru; Miyashita, Mitsuhiro; Sugiyama, Nobuhiro; Washizuka, Shinsuke; Murata, Shiho; Hanihara, Tokiji; Amano, Naoji

    2016-09-01

    We report on two elderly patients with cognitive impairments, for whom chronic carbon monoxide (CO) exposure was suspected based on elevated carboxyhaemoglobin levels in their serum. On their initial visits, cognitive impairment and brain magnetic resonance imaging findings in both patients were compatible with the diagnosis of Alzheimer's-type dementia. However, after discontinuation of the use of a kotatsu, a charcoal-based heater, their serum carboxyhaemoglobin levels normalized and their physical symptoms resolved. Their cognitive function also slightly improved. The causal relationship between physical symptoms and cognitive impairment after chronic CO poisoning is uncertain; however, it is possible that chronic exposure to low CO levels exacerbated the clinical manifestation in our patients.

  4. Charcoal rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Charcoal rot is reported occasionally on alfalfa in the U.S. and has also been found in Australia, Pakistan, Uganda, east Africa, and the former Soviet Union. The fungus causing the disease is widespread throughout tropical and subtropical countries. It causes disease on more than 500 crop and we...

  5. Effects of p-chlorophenoxyisobutyric acid, arabinogalactan, and activated charcoal on microspore embryogenesis in kale.

    PubMed

    Niu, R Q; Zhang, Y; Tong, Y; Liu, Z Y; Wang, Y H; Feng, H

    2015-04-27

    To improve embryogenesis in microspore cultures of kale (Brassica oleracea L. var. acephala DC.), 6-benzylaminopurine (6-BA), naphthaleneacetic acid (NAA), arabinogalactan (AG), p-chlorophenoxyisobutyric acid (PCIB), and activated charcoal (AC) were added to the medium using four varieties of kale. The results showed that the addition of AG (0.1-0.2 g/L), AC (0.1-0.2 g/L) or a combination of 6-BA (0.1-0.2 mg/L) and NAA (0.1-0.2 mg/L) promoted embryo-genesis. Adding 40 μM PCIB or a combination of 40 μM PCIB and 0.2 g/L AC to NLN-13 medium at pH 5.8 effectively enhanced embryogenesis. Treatment with a combination of 40 μM PCIB and 10 mg/L AG gave the highest rate of embryonic induction, especially in genotype "Y007," which showed a twelve-fold increase in yield.

  6. Release of soluble protein from peanut (Arachis hypogaea, Leguminosae) and its adsorption by activated charcoal.

    PubMed

    Kopper, Randall; Van, Trang; Kim, Ara; Helm, Ricki

    2011-01-12

    Peanut (Arachis hypogaea, Leguminosae) allergy is a major cause of food-induced anaphylaxis. The potential use of activated charcoal (AC) to adsorb and reduce the bioavailability of peanut protein allergens for use in the moderation of hypersensitivity reactions was investigated. The rate and extent of protein release from peanut and the adsorption of the solubilized protein by AC was determined under physiological pH values and confirmed in vivo using a porcine animal model system. Peanut proteins were adsorbed with equal efficiency at pH 2 and 7 and are completely removed from solution by an AC/protein ratio of approximately 80:1. This suggests that AC can bind protein under gastric (pH 2) or intestinal (pH 7) conditions. The rapid adsorption of soluble peanut allergens and the continuous binding of allergens released from peanut particulate material suggest the potential efficacy of using AC for gastric decontamination and possible elimination of a biphasic allergic reaction.

  7. Adsorption of ammonium dinitramide (ADN) from aqueous solutions. 1. Adsorption on powdered activated charcoal.

    PubMed

    Santhosh, G; Venkatachalam, S; Ninan, K N; Sadhana, R; Alwan, S; Abarna, V; Joseph, M A

    2003-03-17

    Investigations on the adsorption of ammonium dinitramide (NH(4)N(NO(2))(2)) (ADN) from aqueous solutions on powdered activated charcoal (PAC) were carried out in order to find out an effective and easier method of separating ADN from aqueous solutions. The effectiveness of PAC in the selective adsorption of ADN from aqueous solutions of ADN (ADN-F) and ADN in presence of sulfate (SO(4)(2-)) and nitrate (NO(3)(-)) ions (ADN-PS) was examined and compared using batch and column methods. The adsorption process follows both Langmuir and Freundlich adsorption isotherms and the isotherm parameters for the models were determined. The observed data favor the formation of monolayer adsorption. The adsorption capacities were found to be 63.3, 119, 105.3 and 82 mg of ADN per g of PAC for ADN-F (batch), ADN-PS (batch), ADN-F (column) and ADN-PS (column), respectively. Break-through curves for ADN-F and ADN-PS were obtained for the optimization of separation of ADN from aqueous solutions. Elution curves were generated for the desorption of ADN from PAC using hot water as eluent.

  8. Adsorptive desulphurization study of liquid fuels using Tin (Sn) impregnated activated charcoal.

    PubMed

    Shah, Syed Sikandar; Ahmad, Imtiaz; Ahmad, Waqas

    2016-03-05

    Keeping in view the growing concern regarding desulphurization of petroleum products, the present study was under taken to investigate the efficiency of tin impregnated activated charcoal (Sn-AC) as a potential adsorbent for the desulphurization of model and real commercial straight run kerosene and diesel oil samples. The adsorbent Sn-AC was prepared by wet impregnation process in the laboratory and characterized by SEM, EDX and surface area analysis. Initial experiments were carried out using model oil, which was prepared by dissolving dibenzothiophene (DBT) in cyclohexane, the optimum conditions for desulfurization were found to be, 60°C temperature, 1h contact time and adsorbent dosage of 0.8g, under which about 99.4% of DBT removal was attained. Under optimized conditions the desulfurization of real oil i.e., kerosene and diesel oil was also investigated. Kinetic studies revealed that DBT adsorption followed pseudo second order kinetics and the data best fits in the Langmuir adsorption isotherm as compared to Freundlich adsorption isotherm model. The adsorbent could be easily regenerated simply by washing with toluene for a multiple cycles and reused without losing its efficiency.

  9. Lead(II) adsorption from aqueous solutions by raw and activated charcoals of Melocanna baccifera Roxburgh (bamboo)--a comparative study.

    PubMed

    Lalhruaitluanga, H; Jayaram, K; Prasad, M N V; Kumar, K K

    2010-03-15

    Melocanna baccifera (Poaceae) is the most abundant and economically important non-timber product in state of Mizoram, India. The communities of the region use this potential resource in many ways, charcoal production is one of them. Bamboo charcoal has application in food, pharmaceutical and chemical industries. Activated charcoal was prepared from M. baccifera charcoal by chemical pretreatment in order to make better use of this abundant biomass material. Batch experiments were conducted under varying range of pH (2.0-6.0), contact time (15-360 min) and metal ion concentrations (50-90 mg L(-1)). The optimum conditions for lead biosorption are almost same for M. baccifera raw charcoal (MBRC) and M. baccifera activated charcoal (MBAC)-pH 5.0, contact time 120 min, adsorption capacity q(max) 10.66 mg g(-1) and 53.76 mg g(-1), respectively. However, the biomass of MBAC was found to be more suitable than MBRC for the development of an efficient adsorbent for the removal of lead(II) from aqueous solutions. FTIR analysis revealed that -OH, C-H bending, C=O stretching vibration and carbonyl functional groups were mainly responsible for Pb(II) biosorption. Thus, this study demonstrated that both the charcoal biomass could be used as adsorbents for the treatment of Pb(II) from aqueous solution.

  10. The Radioactivity Characteristics of the NPP Charcoal Sample Contaminated by Carbon-14 - 13531

    SciTech Connect

    Kim, Hee Reyoung

    2013-07-01

    The radioactivity of {sup 14}C-contaminated charcoal sample was analyzed by using a high temperature oxidation and liquid scintillation counting method. The radioactivity of the sample was monotonically increased according to the increase of the combustion time at each temperature where the experimental uncertainty was calculated in the 95 % confidence level. It showed that the {sup 14}C radioactivity was not completely extracted from the sample by simply increasing the combustion time unless the combustion temperature was high enough. The higher the combustion temperature was, the higher the recovery during the first 30 minutes was. The first 30 minute recoveries were 100 % at a temperature equal to or greater than 450 deg. C. The ratios of the recovery during the first 30 minutes to the total recovery during whole duration were more than 90 % at each experiment temperature. It was understood that the temperature was a critical factor for the complete removal of the {sup 14}C from the waste sample. (authors)

  11. Population pharmacokinetics and pharmacodynamics of escitalopram in overdose and the effect of activated charcoal

    PubMed Central

    van Gorp, Freek; Duffull, Stephen; Hackett, L Peter; Isbister, Geoffrey K

    2012-01-01

    AIMS To describe the pharmacokinetics and pharmacodynamics (PKPD) of escitalopram in overdose and its effect on QT prolongation, including the effectiveness of single dose activated charcoal (SDAC). METHODS The data set included 78 escitalopram overdose events (median dose, 140 mg [10–560 mg]). SDAC was administered 1.0 to 2.6 h after 12 overdoses (15%). A fully Bayesian analysis was undertaken in WinBUGS 1.4.3, first for a population pharmacokinetic (PK) analysis followed by a PKPD analysis. The developed PKPD model was used to predict the probability of having an abnormal QT as a surrogate for torsade de pointes. RESULTS A one compartment model with first order input and first-order elimination described the PK data, including uncertainty in dose and a baseline concentration for patients taking escitalopram therapeutically. SDAC reduced the fraction absorbed by 31% and reduced the individual predicted area under the curve adjusted for dose (AUCi/dose). The absolute QT interval was related to the observed heart rate with an estimated individual heart rate correction factor (α = 0.35). The heart rate corrected QT interval (QTc) was linearly dependent on predicted escitalopram concentration [slope = 87 ms/(mg l–1)], using a hypothetical effect-compartment (half-life of effect-delay, 1.0h). Administration of SDAC significantly reduced QT prolongation and was shown to reduce the risk of having an abnormal QT by approximately 35% for escitalopram doses above 200 mg. CONCLUSIONS There was a dose-related lengthening of the QT interval that lagged the increase in drug concentration. SDAC resulted in a moderate reduction in fraction of escitalopram absorbed and reduced the risk of the QT interval being abnormal. PMID:21883384

  12. The pharmacokinetics of sertraline in overdose and the effect of activated charcoal

    PubMed Central

    Cooper, Joyce M; Duffull, Stephen B; Saiao, Ana S; Isbister, Geoffrey K

    2015-01-01

    Aims To investigate the pharmacokinetics (PK) of sertraline in overdose and the effect of single dose activated charcoal (SDAC). Methods Patients presenting to a toxicology unit with sertraline overdoses had demographic and clinical information recorded, and serial serum collected for measurement of sertraline concentrations. Monolix® version 4.2 was used to develop a population PK model of sertraline overdose and the effect of SDAC. Uncertainty in dose time was accounted for by shifting dose time using lag time with between subject variability (BSV). BSV on relative fraction absorbed was used to model uncertainty in dose. Results There were 77 timed sertraline concentrations measured in 28 patients with sertraline overdoses with a median dose of 1550 mg (250–5000 mg). SDAC was given to seven patients between 1.5 and 4 h post-overdose. A one compartment model with lag time of 1 h and first order input and elimination adequately described the data. Including BSV on both lag time and relative fraction absorbed improved the model. The population PK parameter estimates for absorption rate constant, volume of distribution and clearance were 0.895 h−1, 5340 l and 130 l h−1, respectively. The calculated half-life of sertraline following overdose was 28 h (IQR 19.4−30.6h). When given up to 4 h post-overdose, SDAC significantly increased the clearance of sertraline by a factor of 1.9, decreased the area under the curve and decreased the maximum plasma concentration (Cmax). Conclusions Sertraline had linear kinetics in overdose with parameter values similar to those in therapeutic use. SDAC is effective in increasing clearance when given 1.5 to 4 h post-overdose. PMID:25155462

  13. Native Soil Charcoal as a Model for Designing Biochar for Carbon Sequestration

    EPA Science Inventory

    Under changing climate a variety of mechanisms for removing carbon from the atmosphere and sequestering it elsewhere are being considered to reduce the forcing of the atmosphere. Amending soils with biochar has been proposed as one long-term means of sequestering carbon originat...

  14. Activation of waste MDF sawdust charcoal and its reactive dye adsorption characteristics.

    PubMed

    Gan, Q; Allen, S J; Matthews, R

    2004-01-01

    This paper reports an experimental investigation of converting waste medium density fibreboard (MDF) sawdust into chars and activated carbon using chemical activation and thermal carbonisation processes. The MDF sawdust generated during the production of architectural mouldings was characterised and found to have unique properties in terms of fine particle size and high particle density. It also has a high content of urea formaldehyde resin used as a binder in the manufacturing of MDF board. Direct thermal carbonisation and chemical activation of the sawdust by metal impregnation and acid (phosphoric acid) treatment prior to pyrolysis treatment were carried out. The surface morphology of the raw dust, its chars and activated carbon were examined using scanning electron microscopy (SEM). Adsorptive properties and total pore volume of the materials were also analysed using the BET nitrogen adsorption method. Liquid adsorption of a reactive dye (Levafix Brilliant red E-4BA) by the derived sawdust carbon was investigated in batch isothermal adsorption process and the results compared to adsorption on to a commercial activated carbon (Filtrasorb F400). The MDF sawdust carbon exhibited in general a very low adsorption capacity towards the reactive dye, and physical characterisation of the carbon revealed that the conventional chemical activation and thermal carbonisation process were ineffective in developing a microporous structure in the dust particles. The small size of the powdery dust, the high particle density, and the presence of the urea formaldehyde resin all contributed to the difficulty of developing a proper porous structure during the thermal and chemical activation process. Finally, activation of the dust material in a consolidated form (cylindrical pellet) only achieved very limited improvement in the dye adsorption capacity. This original study, reporting some unexpected outcomes, may serve as a stepping-stone for future investigations of recycle and

  15. A theoretical model for {sup 222}Rn adsorption on activated charcoal canisters in humid air based on Polanyi`s potential theory

    SciTech Connect

    Scarpitta, S.C.

    1995-03-01

    Water vapor interferes with adsorption {sup 222}Rn gas by passive activated charcoal devices used to estimate indoor air concentrations. The {sup 222}Rn adsorption coefficient is the fundamental parameter characterizing charcoal`s ability to adsorb {sup 222}Rn. The Dubinin-Radushkevich equation, based on Polanyi`s potential theory, was modified to include two terms quantifying the effect of both water vapor and sampling time on the {sup 222}Rn adsorption coefficient of passive charcoal devices. A single equation was derived that quantities the {sup 222}Rn adsorption coefficients at any temperature, humidity and exposure time using six experimentally determined physical constants that are unique for a particular passive charcoal device. The theoretical model was verified with published experimental data, and it showed a good correlation between theory and experiment. The model proved to be consistent with experimental data, provided that the amount of water vapor adsorbed by the charcoal device during sampling remains below a critical level, termed the breakpoint. 44 refs., 5 figs., 2 tabs.

  16. Carcinogenic PAH in waterpipe charcoal products

    PubMed Central

    Sepetdjian, Elizabeth; Saliba, Najat; Shihadeh, Alan

    2010-01-01

    Because narghile waterpipe (shisha, hooka) smoking normally involves the use of burning charcoal, smoke inhaled by the user contains constituents originating from the charcoal in addition to those from the tobacco. We have previously found that charcoal accounts for most of the polyaromatic hydrocarbons (PAH) and carbon monoxide in the smoke of the waterpipe, both of which are present in alarming quantities. Because charcoal manufacturing conditions favor formation of PAH, it is reasonable to assume that charcoal sold off the shelf may be contaminated by PAH residues. These residues may constitute a significant fraction of the PAH inhaled by the waterpipe user and those in her/his vicinity. We measured PAH residues on three kinds of raw waterpipe charcoal sampled from Beirut stores and cafés. We found that PAH residues in raw charcoal can account for more than half of the total PAH emitted in the mainstream and sidestream smoke, and about one sixth of the carcinogenic 5- and 6-ring PAH compounds. Total PAH content of the three charcoal types varied systematically by a factor of six from the charcoal with the least to the greatest PAH residue. These findings indicate the possibility of regulating charcoal carcinogen content. PMID:20807559

  17. Adsorption saturation and chromatographic distortion effects on passive headspace sampling with activated charcoal in fire debris analysis.

    PubMed

    Williams, Mary R; Fernandes, Denise; Bridge, Candice; Dorrien, Derek; Elliott, Stefanie; Sigman, Michael

    2005-03-01

    Distortion of the chromatographic profile obtained for hydrocarbons that have been sampled by adsorption onto activated charcoal is a well-known phenomenon. The work reported here helps to better define the causes of chromatographic profile distortion and offers a potential method to avoid chromatographic distortion in some cases through a subsampling technique. The recovery of hydrocarbons from an equimolar mixture was investigated to determine the influence of hydrocarbon concentration on the molar ratios of recovered components. In a one-quart container, hydrocarbon volumes as small as 24 microL (liquid) were sufficient to saturate the surface area available for adsorption on a 99.0 mm2 square of activated charcoal, resulting in significant distortions in the molar ratio and the chromatographic profile of the recovered hydrocarbons. Passive headspace sampling of a similarly small volume of unweathered gasoline spiked onto carpet padding resulted in a significant distortion of the chromatographic profile. The chromatographic profile of the recovered hydrocarbons closely resembled 75% weathered gasoline. Heating the container spiked with unweathered gasoline to evenly distribute the components and then removing a subsample of the carpet padding to a second container for passive headspace analysis greatly reduced the amount of distortion in the resulting chromatogram.

  18. Effect of filtration by activated charcoal on the toxicological activity of cigarette mainstream smoke from experimental cigarettes.

    PubMed

    Gaworski, Charles L; Schramke, Heike; Diekmann, Joerg; Meisgen, Thomas J; Tewes, Franz J; Veltel, Detlef J; Vanscheeuwijck, Patrick M; Rajendran, Narayanan; Muzzio, Miguel; Haussmann, Hans-Juergen

    2009-07-01

    Activated charcoal (AC) filtration reportedly decreases the yields of smoke vapor phase constituents including some identified as human carcinogens and respiratory irritants. Non-clinical studies including chemical smoke analysis, in vitro cytotoxicity and mutagenicity (bacterial and mammalian cells), and in vivo subchronic rat inhalation studies were carried out using machine smoking at ISO conditions with lit-end research cigarettes containing AC filters. The objective was to assess whether AC filter technology would alter the established toxicity profile of mainstream smoke by increasing or decreasing any known toxicological properties, or elicit new ones. The reduced yield of vapor phase irritants from AC filter cigarettes correlated with markedly decreased in vitro cytotoxicity and in vivo morphology of the nose and lower respiratory tract. Increased yields of particulate phase constituents (e.g. polycyclic aromatic hydrocarbons) in AC filtered smoke were noted in comparison to controls in some studies. The in vitro bacterial mutagenicity of AC filtered smoke particulate preparations was occasionally increased over control levels. Laryngeal epithelial thickness was increased in some rats inhaling AC filtered smoke in comparison to controls, an effect perhaps related to higher inspiratory flow. When tested under more intense Massachusetts Department of Public Health smoking conditions, AC filter associated reductions in vapor phase constituent yields were smaller than those seen with ISO conditions, but the effect on in vitro cytotoxicity remained.

  19. How feasible is it to conform to the European guidelines on administration of activated charcoal within one hour of an overdose?

    PubMed Central

    Karim, A; Ivatts, S; Dargan, P; Jones, A

    2001-01-01

    Methods—63 patients who had taken potentially serious overdoses and required hospital admission from a London teaching hospital A&E department were identified over a six month period. The patients' case notes were analysed for age, sex, substances taken, and the timing of their management within the A&E department. Results—Median time of arrival after overdose was 136 minutes, and only 15 patients presented within an hour. Ten of these 15 patients were given activated charcoal, and only four of the 10 received it within the one hour limit. Sixteen patients received charcoal outside the time limit. Subanalysis of the individual cases given charcoal shows that triaging is fast (median five minutes), but a significant time delay occurs after this before charcoal is administered (median 21 minutes). Conclusions—These results are likely to be exaggerated in rural hospitals and demonstrate the difficulty of adhering to the recommended guidelines, unless activated charcoal can be safely administered to appropriate patients in the prehospital environment. PMID:11559618

  20. Impact of land-use and long-term (>150 years) charcoal accumulation on microbial activity, biomass and community structure in temperate soils (Belgium).

    NASA Astrophysics Data System (ADS)

    Hardy, Brieuc; Cornelis, Jean-Thomas; Dufey, Joseph E.

    2015-04-01

    In the last decade, biochar has been increasingly investigated as a soil amendment for long-term soil carbon sequestration while improving soil fertility. On the short term, biochar application to soil generally increases soil respiration as well as microbial biomass and activity and affects significantly the microbial community structure. However, such effects are relatively short-term and tend to vanish over time. In our study, we investigated the long-term impact of charcoal accumulation and land-use on soil biota in temperate haplic Luvisols developed in the loess belt of Wallonia (Belgium). Charcoal-enriched soils were collected in the topsoil of pre-industrial (>150 years old) charcoal kilns in forest (4 sites) and cropland (5 sites). The topsoil of the adjacent charcoal-unaffected soils was sampled in a comparable way. Soils were characterized (pH, total, organic and inorganic C, total N, exchangeable Ca, Mg, K, Na, cation exchange capacity and available P) and natural soil organic matter (SOM) and black carbon (BC) contents were determined by differential scanning calorimetry. After rewetting at pF 2.5, soils were incubated during 140 days at 20 °C. At 70 days of incubation, 10 g of each soil were freeze dried in order to measure total microbial biomass and community structure by PLFA analysis. The PLFA dataset was analyzed by principal component analysis (PCA) while soil parameters were used as supplementary variables. For both agricultural and forest soils, the respiration rate is highly related to the total microbial biomass (R²=0.90). Both soil respiration and microbial biomass greatly depend on the SOM content, which indicates that the BC pool is relatively inert microbiologically. Land-use explains most of the variance in the PLFA dataset, largely governing the first principal component of the ACP. In forest soils, we observe a larger proportion of gram + bacteria, actinomycetes and an increased bacteria:fungi ratio compared to cropland, where gram

  1. An Investigation into Techniques for the Determination of Moisture Content on Activated Carbon

    DTIC Science & Technology

    1991-09-01

    Activated carbon (or charcoal ) is a universal adsorbent for the removal of a variety of organic/inorganic contaminants, in both gaseous and aqueous phase...AD-A245 938 i * *~fl Nadoni Waren AN INVESTIGATION INTO TECHNIQUES FOR THE DETERMNATION OF MOISTURE CONTENT ON ACTIVATED CARBON (U) by L.E. Cameron...INVESTIGATION INTO TECHNIQUES FOR THE DETERMINATION OF MOISTURE CONTENT ON ACTIVATED CARBON (U) by L.E. Cameron and S.H.C. Liang Chemical Protecti

  2. Combustion characteristics of husk charcoal

    SciTech Connect

    Shimizu, H.; Kimura, T.; Nishiyama, Y.; Terui, T.

    1984-07-01

    This paper analyzes the factors involved in the extraordinary temperature generation in husk combustion furnaces, and investigates methods of protecting furnaces from heat damage. The combustion characteristics of fixed carbon in rice husks are examined in relation to the air flow rate using different husk charcoals. The theoretical flame temperature in a practical bed was determined from the combustion propagation velocity. It is determined that deviation from the regression line relating the combustion propagation velocity with the specific air flow rate showed a slight correlation with the bulk density of the charcoal samples used.

  3. Production and characterization of activated carbons from cereal grains

    SciTech Connect

    Venkatraman, A.; Walawender, S.P.; Fan, L.T.

    1996-10-01

    The kernels of grain such as corn and hard red winter wheat were subjected to a two-stage pyrolytic process to generate relatively high yields of charcoals. The process involved carbonization of the kernels at low temperatures (250-325{degrees}C) followed by complete devolatilization of the resultant charcoals at around 750{degrees}C. The charcoals were subsequently activated physically with CO{sub 2} at 800{degrees}C to yield activated carbons. The total pore volumes and surface areas of the activated carbons were determined at various degree of activation by physisorption methods. The surface areas from the nitrogen BET method ranged from 500 to 1750 m{sup 2}/g, while the total pore volumes obtained from the volumes at saturation were in the interval from 0.3 to 0.7 cm{sup 3}/g. The fractal nature of the pore interfaces as well as the existence of different types of pores were investigated through small-angle x-ray scattering.

  4. Effects of pH and inorganic salts on the adsorption of phenol from aqueous systems on activated decolorizing charcoal

    SciTech Connect

    Halhouli, K.A.; Darwish, N.A.; Al-Dhoon, N.M.

    1995-10-01

    An experimental investigation of the effects of pH and three inorganic salts (KCl, KI, and NaCl) on the adsorption isotherms of phenol (from a dilute aqueous solution) on activated charcoal was conducted. Each salt was studied at three different concentrations, i.e., 0.1, 0.01, and 0.005 M. The effect of pH (in the pH range 3 to 11) in the presence of KI, KCl, and NaCl was also investigated. The concentration of phenol in the aqueous systems studied ranged from 10 to 200 ppm. The temperature effect was also studied, and the resulting experimental equilibrium isotherms at 30, 40, and 55{degrees}C are well represented by Freundlich, Langmuir, and Redlich-Paterson isotherms. The relevant parameters for these isotherms are presented.

  5. Development of a technique for the measurement of the radon exhalation rate using an activated charcoal collector.

    PubMed

    Iimoto, Takeshi; Akasaka, Yoshinori; Koike, Yuya; Kosako, Toshiso

    2008-04-01

    A simple system to evaluate the 222Rn (radon) exhalation rate from soil has been improved. A sampling cuvette of 2.1 L is placed so that it covers the targeted ground soil, and radon emanating from the soil accumulates within the cuvette for 24 h. Its internal radon concentration is measured by the combination of an activated charcoal (PICO-RAD) and a liquid scintillation counting system. This study shows variations of the conversion factor (CF: unit Bq m(-3)/cpm) of PICO-RAD. The range of CF due to temperature (10-30 degrees C) was between -21% and +69%, and this due to humidity (30-90%) was between 0% and -15%. Humidity and radon concentration in the cuvette covering soil tended to saturate in a few hours. The above information was used to correct the CF for the evaluation. The improved system shows high reliability and can be easily applied to natural environments.

  6. Somatic proembryo production from excised, wounded zygotic carrot embryos on hormone-free medium: evaluation of the effects of pH, ethylene and activated charcoal

    NASA Technical Reports Server (NTRS)

    Smith, D. L.; Krikorian, A. D.

    1990-01-01

    Wounded zygotic embryos of cultivated carrot produce somatic proembryos on hormone-free nutrient medium containing 1 mM NH4+ as the sole nitrogen source. Continued maintenance of proembryos on this medium leads to a "pure" culture of preglobular stage proembryos (PGSPs). Ethylene had no effect on this process. Also, somatic embryo production was not affected by growing cultures on activated charcoal-impregnated filter papers. However, somatic proembyros initiated on activated charcoal papers were not maintainable as PGSPs and developed into later embryo stages. Normally, medium pH dropped from 5.7 to 4 during each subculture period, but when using activated charcoal papers the pH endpoint was around 6 - 7 due to a leachable substance(s) within the filter papers. When powdered, activated charcoal was used in the medium as an adsorbent of products potentially released after wounding, pH dropped at the normal rate and to the expected levels; proembryos did not mature into later embryo stages and were maintainable exclusively as PGSPs. Low pH (approximately 4) is detrimental to proembyro production, but is essential to maintaining PGSPs on hormone-free nutrient medium, whereas a sustained pH > or = 5.7 allows continued development of PGSPs into later embryo stages.

  7. Clarifying the role of activated charcoal filters in preparing an anaesthetic workstation for malignant hyperthermia-susceptible patients.

    PubMed

    Bilmen, J G; Gillies, R I

    2014-01-01

    Malignant hyperthermia (MH) is a life-threatening condition caused by exposure of susceptible individuals to volatile anaesthetics or suxamethonium. MH-susceptible individuals must avoid exposure to these drugs, so accurate and reproducible processes to remove residual anaesthetic agents from anaesthetic workstations are required. Activated charcoal filters (ACFs) have been used for this purpose. ACFs can reduce the time for preparing an anaesthetic workstation for MH patients. Currently, the only commercially available ACFs are the Vapor-Clean$trade; (Dynasthetics, Salt Lake City, UT, USA) filters which retail at approximately AUD$130 per set of two, both of which are to be used in a single anaesthetic. Anaesthetic workstations were saturated with anaesthetic vapours and connected to a Miran ambient air analyser (SapphRe XL, ThermoScientific, Waltham, MA, USA) to measure vapour concentration. Various scenarios were tested in order to determine the most economical configurations of machine flushing, component change and activated charcoal filter use. We found that placement of filters in an unprepared, saturated circuit was insufficient to safely prepare an anaesthetic workstation. Following flushing of the anaesthetic workstation with high-flow oxygen for 90 seconds, a circuit and soda lime canister change and the placement of an ACF on the inspiratory limb, we were able to safely prepare a workstation in less than three minutes. A single filter on the inspiratory limb was able to maintain a clean circuit for 12 hours, with gas flows dropped from 10 lpm to 3 lpm after 90 minutes or removal of the filter after 90 minutes if high gas flows were maintained.

  8. Handbook of charcoal making: the traditional and industrial methods

    SciTech Connect

    Emrich, W.

    1985-01-01

    The reviewer credits this handbook with expanding knowledge about the economic value of charcoal, particularly in the European area. The 10 chapters are: (1) history and fundamentals of the charcoal process, (2) traditional methods of the smallholder producer, (3) concepts and technology for the industrial producer, (4) recovering commercial products from pyrolysis oil, (5) raw materials supply, (6) end-use markets for by-products, (7) planning a charcoal venture, (8) charcoal briquettes and activated charcoal, (9) safety precautions and environmental considerations, and (10) charcoal laboratory work. Each chapter lists references. There are four appendices.

  9. Charcoal kiln relicts - a favorable site for tree growth?

    NASA Astrophysics Data System (ADS)

    Buras, Allan; Hirsch, Florian; van der Maaten, Ernst; Takla, Melanie; Räbiger, Christin; Cruz Garcia, Roberto; Schneider, Anna; Raab, Alexandra; Raab, Thomas; Wilmking, Martin

    2015-04-01

    Soils with incompletely combusted organic material (aka 'black carbon') are considered fertile for plant growth. Considerable enrichment of soils with black carbon is known from Chernozems, from anthropogenic induced altering of soils like the 'Terra Preta' in South America (e.g. Glaser, 2001), and from charcoal kiln relicts. Recent studies have reported a high spatial frequency of charcoal kiln relicts in the Northeastern German lowlands (Raab et al., 2015), which today are often overgrown by forest plantations. In this context the question arises whether these sites are favorable for tree growth. Here we compare the performance of 22 Pinus sylvestris individuals - a commonly used tree species in forestry - growing on charcoal kiln relicts with 22 control trees. Growth performance (height growth and diameter growth) of the trees was determined using dendrochronological techniques, i.e. standard ring-width measurements were undertaken on each two cores per tree and tree height was measured in the field. Several other wood properties such as annual wood density, average resin content, as well as wood chemistry were analyzed. Our results indicate that trees growing on charcoal kiln relicts grow significantly less and have a significantly lower wood density in comparison with control trees. Specific chemical components such as Manganese as well as resin contents were significantly higher in kiln trees. These results highlight that tree growth on charcoal kiln relicts is actually hampered instead of enhanced. Possibly this is a combined effect of differing physical soil properties which alter soil water accessibility for plants and differing chemical soil properties which may negatively affect tree growth either if toxic limits are surpassed or if soil nutrient availability is decreased. Additional soil analyses with respect to soil texture and soil chemistry shall reveal further insight into this hypothesis. Given the frequent distribution of charcoal kiln relicts in

  10. Activated carbon from biomass

    NASA Astrophysics Data System (ADS)

    Manocha, S.; Manocha, L. M.; Joshi, Parth; Patel, Bhavesh; Dangi, Gaurav; Verma, Narendra

    2013-06-01

    Activated carbon are unique and versatile adsorbents having extended surface area, micro porous structure, universal adsorption effect, high adsorption capacity and high degree of surface reactivity. Activated carbons are synthesized from variety of materials. Most commonly used on a commercial scale are cellulosic based precursors such as peat, coal, lignite wood and coconut shell. Variation occurs in precursors in terms of structure and carbon content. Coir having very low bulk density and porous structure is found to be one of the valuable raw materials for the production of highly porous activated carbon and other important factor is its high carbon content. Exploration of good low cost and non conventional adsorbent may contribute to the sustainability of the environment and offer promising benefits for the commercial purpose in future. Carbonization of biomass was carried out in a horizontal muffle furnace. Both carbonization and activation were performed in inert nitrogen atmosphere in one step to enhance the surface area and to develop interconnecting porosity. The types of biomass as well as the activation conditions determine the properties and the yield of activated carbon. Activated carbon produced from biomass is cost effective as it is easily available as a waste biomass. Activated carbon produced by combination of chemical and physical activation has higher surface area of 2442 m2/gm compared to that produced by physical activation (1365 m2/gm).

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

    SciTech Connect

    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 H{sub 2}O 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 H{sub 2}O 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.

  12. Adsorption of dimethyl sulfide from aqueous solution by a cost-effective bamboo charcoal.

    PubMed

    Wang, Ming; Huang, Zheng-Hong; Liu, Guangjia; Kang, Feiyu

    2011-06-15

    The adsorption of dimethyl sulfide from an aqueous solution by a cost-effective bamboo charcoal from Dendrocalamus was studied in comparison with other carbon adsorbents. The bamboo charcoal exhibited superior adsorption on dimethyl sulfide compared with powdered activated carbons at different adsorbent dosages. The adsorption characteristics of dimethyl sulfide onto bamboo charcoal were investigated under varying experimental conditions such as particle size, contact time, initial concentration and adsorbent dosage. The dimethyl sulfide removal was enhanced from 31 to 63% as the particle size was decreased from 24-40 to >300 mesh for the bamboo charcoal. The removal efficiency increased with increasing the adsorbent dosage from 0.5 to 10mg, and reached 70% removal efficiency at 10mg adsorbed. The adsorption capacity (μg/g) increased with increasing concentration of dimethyl sulfide while the removal efficiency decreased. The adsorption process conforms well to a pseudo-second-order kinetics model. The adsorption of dimethyl sulfide is more appropriately described by the Freundlich isotherm (R(2), 0.9926) than by the Langmuir isotherm (R(2), 0.8685). Bamboo charcoal was characterized by various analytical methods to understand the adsorption mechanism. Bamboo charcoal is abundant in acidic and alcohol functional groups normally not observed in PAC. A distinct difference is that the superior mineral composition of Fe (0.4 wt%) and Mn (0.6 wt%) was detected in bamboo charcoal-elements not found in PAC. Acidic functional group and specific adsorption sites would be responsible for the strong adsorption of dimethyl sulfide onto bamboo charcoal of Dendrocalamus origin.

  13. Gastrointestinal transit measurements in mice with 99mTc-DTPA-labeled activated charcoal using NanoSPECT-CT

    PubMed Central

    2013-01-01

    Background Gastrointestinal (GI) disorders are commonly associated with chronic conditions such as diabetes, obesity, and hypertension. Direct consequences are obstipation or diarrhea as opposite aspects of the irritable bowel syndrome, and more indirectly, alteration of appetite, feeling of fullness, flatulence, bloatedness, and eventually leading to altered absorption of nutrients. Moreover, GI retention and passage times have been recognized as important factors in determining the release site and hence the bioavailability of orally administered drugs. To facilitate the understanding of physiological and pathological processes involved, it is necessary to monitor the gut motility in animal models. Here, we describe a method for studying the GI transit time using technetium-labeled activated charcoal diethylenetriaminepentaacetic acid (99mTc-Ch-DTPA) detected by single-photon emission computed tomography (SPECT). Methods Tc-DTPA was adsorbed onto activated charcoal and administered orally to trypan blue-tainted (n = 4) 129SvEv mice (50 to 80 MBq/animal, n = 11). The exact distribution and movement of radioactivity in the gastrointestinal tract was measured at intervals of 1, 3, 6, 12, and 22 h by SPECT-CT. In addition, in order to validate the imaging of GI transient time, loperamide (0.25 mg/animal, n = 3) was used to delay the GI transit. Results The transit time measured as the peak radioactivity occurring in the rectum was 6 to 7 h after gavaging of 99mTc-Ch-DTPA. After 1 h, the bolus had passed into the small intestine and entered the cecum and the colon. At 6 and 8 h, the cecum, the ascending, transverse, and descending colon, and the rectum showed significant labeling. Several pellets were stored in the rectum for defecation. After 22 h, little activity remained in the stomach and none was detected in the transverse colon or other GI locations. In contrast, 6 h after administration of loperamide, only the cecum and part of the transverse colon were labeled

  14. MOF@activated carbon: a new material for adsorption of aldicarb in biological systems.

    PubMed

    de Oliveira, Carlos Alberto Fernandes; da Silva, Fausthon Fred; Jimenez, George Chaves; Neto, José Ferreira da S; de Souza, Daniela Maria Bastos; de Souza, Ivone Antônia; Alves, Severino

    2013-07-25

    A new composite was synthesized by the hydrothermal method using a 3D coordination network [Ln2(C4H4O4)3(H2O)2]·H2O (Ln = Eu and Tb) and activated carbon. The coordination network is formed within the pores of the charcoal, allowing for the use of this material as a detoxifying agent.

  15. Facile xenon capture and release at room temperature using a metal-organic framework: a comparison with activated charcoal

    SciTech Connect

    Thallapally, Praveen K.; Grate, Jay W.; Motkuri, Radha K.

    2012-01-11

    Two well known Metal organic frameworks (MOF-5, NiDOBDC) were synthesized and studied for facile xenon capture and separation. Our results indicate the NiDOBDC adsorbs significantly more xenon than MOF-5, releases it more readily than activated carbon, and is more selective for Xe over Kr than activated carbon.

  16. Soil organic matter dynamics and microbial activity in a cropland and soil treated with wood ash containing charcoal

    NASA Astrophysics Data System (ADS)

    Omil, B.; Fonturbel, M. T.; Vega, J. A.; Balboa, M. A.; Merino, A.

    2012-04-01

    Wood ash is generated as a by-product of biomass combustion in power plants, and can be applied to soil to improve nutritional status and crop production. The application of mixed wood ash, a mixture of ash and charcoal, may also improve the SOM content and quality. The charcoal contained in mixed wood ash is a pyrogenic organic material, a heterogeneous mixture of thermally altered polymers with aromatic domains. This structure may favour oxidation, facilitating further microbial attack and generation of new SOM compounds. In addition, accelerated C mineralization of this material may also be due to the priming effect of the rhizosphere, which may even enhance the decomposition of more recalcitrant SOM. The study was carried out in a field devoted to cereal crops during the last few decades. The soil was acidic (pH 4.5) with a low SOC content (3 %). The experiment was based on a randomised block design with four replicates. Each block included the following four treatments: Control, 16 Mg fly wood ash, 16 Mg mixed wood ash and 32 Mg mixed wood ash ha-1. The ash used in the study was obtained from a thermal power plant and was mainly derived from the combustion of Pinus radiata bark. The changes in SOM were monitored over two years by solid state 13C CPMAS NMR and Differential Scanning Calorimetry (DSC). The changes in microbial activity were studied by analysis of microbial biomass C and basal respiration. The soil bacterial community was studied by the Biolog method. Both 13 C-CPMAS NMR spectra and DSC curves revealed that the SOM in the treated soils displayed a higher degree of aromaticity than in the untreated soils, indicating a gain in more stable SOM compounds. However, both methods also revealed increases in other labile C compounds. Microbial biomass and soil respiration increased significantly as a result of these effects and possibly also due to a priming effect. The treatments also led to increases in the functional diversity indices. The amended soils

  17. Heavy metal removal from MSWI fly ash by electrokinetic remediation coupled with a permeable activated charcoal reactive barrier

    NASA Astrophysics Data System (ADS)

    Huang, Tao; Li, Dongwei; Kexiang, Liu; Zhang, Yuewei

    2015-10-01

    This paper presents the investigations into the feasibility of the application of a remediation system that couples electrokinetic remediation (EKR) with the permeable reactive barrier (PRB) concept for municipal solid waste incineration (MSWI) fly ash with activated charcoal as the PRB material. The experimental results of this study showed that the proposed combined method can effectively improve the remediation efficiency and that the addition of the oxalic acid to the PRB media before the coupled system can further enhance the remediation process. In the optimization tests, the maximum removals of Zn, Pb, Cu and Cd were achieved under different experimental conditions. The voltage gradient and processing time were shown to have significant effects on the removal of Cu and Cd, whereas the addition of the oxalic acid had a more significant influence on the removal of Pb. Generally, the processing time is the most significant factor in changing the removal rates of HMs in the enhanced coupled system. In terms of the leaching toxicity, the specimen remediated by ENEKR + PRB showed the lowest leaching value for each HM in the S2 and S3 regions.

  18. A simple and rapid technique for radiochemical separation of iodine radionuclides from irradiated tellurium using an activated charcoal column.

    PubMed

    Chattopadhyay, Sankha; Saha Das, Sujata

    2009-10-01

    A simple and inexpensive method for the separation of medically useful no-carrier-added (nca) iodine radionuclides from bulk amounts of irradiated tellurium dioxide (TeO(2)) target was developed. The beta(-) emitting (131)I radionuclide, produced by the decay of (131)Te through the (nat)Te(n, gamma)(131)Te nuclear reaction, was used for standardization of the radiochemical separation procedure. The radiochemical separation was performed by precipitation followed by column (activated charcoal) chromatography. Quantitative post-irradiation recovery of the TeO(2) target material (98-99%), in a form suitable for reuse in future irradiations, was achieved. The overall radiochemical yield for the complete separation of (131)I was 75-85% (n=8). The separated nca (131)I was of high, approximately 99%, radionuclidic and radiochemical purities and did not contain detectable amounts of the target material. This method can be adopted for the radiochemical separation of other different iodine radionuclides produced from tellurium matrices through cyclotron as well as reactor irradiation.

  19. Heavy metal removal from MSWI fly ash by electrokinetic remediation coupled with a permeable activated charcoal reactive barrier.

    PubMed

    Huang, Tao; Li, Dongwei; Kexiang, Liu; Zhang, Yuewei

    2015-10-21

    This paper presents the investigations into the feasibility of the application of a remediation system that couples electrokinetic remediation (EKR) with the permeable reactive barrier (PRB) concept for municipal solid waste incineration (MSWI) fly ash with activated charcoal as the PRB material. The experimental results of this study showed that the proposed combined method can effectively improve the remediation efficiency and that the addition of the oxalic acid to the PRB media before the coupled system can further enhance the remediation process. In the optimization tests, the maximum removals of Zn, Pb, Cu and Cd were achieved under different experimental conditions. The voltage gradient and processing time were shown to have significant effects on the removal of Cu and Cd, whereas the addition of the oxalic acid had a more significant influence on the removal of Pb. Generally, the processing time is the most significant factor in changing the removal rates of HMs in the enhanced coupled system. In terms of the leaching toxicity, the specimen remediated by ENEKR + PRB showed the lowest leaching value for each HM in the S2 and S3 regions.

  20. Removal of residual colonic ciprofloxacin in the rat by activated charcoal entrapped within zinc-pectinate beads.

    PubMed

    Khoder, Mouhamad; Tsapis, Nicolas; Domergue-Dupont, Valérie; Gueutin, Claire; Fattal, Elias

    2010-10-09

    Residual antibiotics reaching the colon have many deleterious effects on the colonic microbiota including the selection of new antibiotic resistances. In order to avoid the selection of ciprofloxacin resistance, intestine or colon-targeted zinc-pectinate beads containing activated charcoal (AC) were designed for the inactivation of residual ciprofloxacin in the gastrointestinal tract of rats. Bead stability after oral administration was adjusted by tuning the concentration of zinc in the gelling bath and the number of washings. Intestine and colon-targeted beads were administered along with 50mg/kg of ciprofloxacin and ciprofloxacin was dosed in the plasma and the feces using HPLC. Ciprofloxacin pharmacokinetics was not affected by the oral co-administration of beads. The co-administration of intestine-targeted beads led to a significant decrease of the residual fecal free ciprofloxacin with a pronounced dose effect. Our study suggests the rat model is not appropriate for the investigation of bacteria responsive colon-targeted beads probably due to the important anatomical and physiological differences between human and rat gastrointestinal tracts. The ability of AC loaded zinc-pectinate beads to selectively decrease the intestinal residual fraction of ciprofloxacin could provide a better protection of the intestinal microbiota and may prevent the emergence of ciprofloxacin resistance in the gastrointestinal tract.

  1. Heavy metal removal from MSWI fly ash by electrokinetic remediation coupled with a permeable activated charcoal reactive barrier

    PubMed Central

    Huang, Tao; Li, Dongwei; Kexiang, Liu; Zhang, Yuewei

    2015-01-01

    This paper presents the investigations into the feasibility of the application of a remediation system that couples electrokinetic remediation (EKR) with the permeable reactive barrier (PRB) concept for municipal solid waste incineration (MSWI) fly ash with activated charcoal as the PRB material. The experimental results of this study showed that the proposed combined method can effectively improve the remediation efficiency and that the addition of the oxalic acid to the PRB media before the coupled system can further enhance the remediation process. In the optimization tests, the maximum removals of Zn, Pb, Cu and Cd were achieved under different experimental conditions. The voltage gradient and processing time were shown to have significant effects on the removal of Cu and Cd, whereas the addition of the oxalic acid had a more significant influence on the removal of Pb. Generally, the processing time is the most significant factor in changing the removal rates of HMs in the enhanced coupled system. In terms of the leaching toxicity, the specimen remediated by ENEKR + PRB showed the lowest leaching value for each HM in the S2 and S3 regions. PMID:26486449

  2. Preparation of activated carbons from macadamia nut shell and coconut shell by air activation

    SciTech Connect

    Tam, M.S.; Antal, M.J. Jr.

    1999-11-01

    A novel, three-step process for the production of high-quality activated carbons from macadamia nut shell and coconut shell charcoals is described. In this process the charcoal is (1) heated to a high temperature (carbonized), (2) oxidized in air following a stepwise heating program from low (ca. 450 K) to high (ca. 660 K) temperatures (oxygenated), and (3) heated again in an inert environment to a high temperature (activated). By use of this procedure, activated carbons with surface areas greater than 1,000 m{sub 2}/g are manufactured with an overall yield of 15% (based on the dry shell feed). Removal of carbon mass by the development of mesopores and macropores is largely responsible for increases in the surface area of the carbons above 600 m{sub 2}/g. Thus, the surface area per gram of activated carbon can be represented by an inverse function of the yield for burnoffs between 15 and 60%. These findings are supported by mass-transfer calculations and pore-size distribution measurements. A kinetic model for gasification of carbon by oxygen, which provides for an Eley-Rideal type reaction of a surface oxide with oxygen in air, fits the measured gasification rates reasonably well over the temperature range of 550--660 K.

  3. Chemical and structural evaluation of activated carbon prepared from jute sticks for Brilliant Green dye removal from aqueous solution.

    PubMed

    Asadullah, Mohammad; Asaduzzaman, Mohammad; Kabir, Mohammad Shajahan; Mostofa, Mohammad Golam; Miyazawa, Tomohisa

    2010-02-15

    Activated carbons have been prepared from jute sticks by chemical activation using ZnCl(2) and physical activation using steam for the removal of Brilliant Green dye from aqueous solution. The activated carbons and charcoal prepared from jute sticks were characterized by evaluating the surface chemistry, structural features and surface morphology. The maximum BET surface area was obtained to be 2304 m(2)/g for chemical activated carbon (ACC) while it is 730 and 80 m(2)/g for steam activated carbon (ACS) and charcoal, respectively. The FT-IR spectra exhibited that the pyrolysis and steam activation of jute sticks resulted in the release of aliphatic and O-containing functional groups by thermal effect. However, the release of functional groups is the effect of chemical reaction in the ZnCl(2) activation process. A honeycomb-type carbon structure in ACC was formed as observed on SEM images. Although charcoal and ACC were prepared at 500 degrees C the ACC exhibited much lower Raman sensitivity due to the formation of condensed aromatic ring systems. Due to high surface area and high porous structure with abundance of functional groups, the ACC adsorbed dye molecules with much higher efficiency than those of ACS and charcoal.

  4. Activated carbon material

    DOEpatents

    Evans, A. Gary

    1978-01-01

    Activated carbon particles for use as iodine trapping material are impregnated with a mixture of selected iodine and potassium compounds to improve the iodine retention properties of the carbon. The I/K ratio is maintained at less than about 1 and the pH is maintained at above about 8.0. The iodine retention of activated carbon previously treated with or coimpregnated with triethylenediamine can also be improved by this technique. Suitable flame retardants can be added to raise the ignition temperature of the carbon to acceptable standards.

  5. Determination of trace elements in medicinal activated charcoal using slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry with low vaporization temperature.

    PubMed

    Chen, Chien-Chou; Jiang, Shiuh-Jen; Sahayam, A C

    2015-01-01

    The determination of Cd, Sb, Te, Hg, Tl and Pb in medicinal activated charcoal by ultrasonic slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry (USS-ETV-ICP-MS) was described. EDTA was used as the modifier to enhance the volatility of elements studied. The influences of instrument operating conditions and slurry preparation on the ion signals were studied. A relatively low vaporization temperature of 1000°C was used, which separated the analyte from the major matrix components that improved ion signals. The method has been applied to determine Cd, Sb, Te, Hg, Tl and Pb in an NIST SRM 1633b Coal Fly Ash reference material and three brands of medicinal activated charcoal capsules using isotope dilution and standard addition calibration methods. The concentrations that are in ng g(-1) levels were in good agreement between different calibration methods. The precision between sample replicates was better than 7% with USS-ETV-ICP-MS technique. The method detection limit estimated from standard addition curves was 0.4, 0.3, 0.3, 0.3, 0.04 and 0.9 ng g(-1) for Cd, Sb, Te, Hg, Tl and Pb, respectively, in original medicinal activated charcoal.

  6. Synthesis of activated charcoal supported Bi-doped TiO2 nanocomposite under solar light irradiation for enhanced photocatalytic activity

    NASA Astrophysics Data System (ADS)

    Chandraboss, V. L.; Kamalakkannan, J.; Senthilvelan, S.

    2016-11-01

    In this study, activated charcoal (AC) supported bismuth (Bi)-doped Titanium dioxide (TiO2) nanocomposite was synthesized by precipitation method. The photocatalytic activity of AC-Bi/TiO2 was investigated for the degradation of methylene blue (MB) in aqueous solution under solar light irradiation. The incorporation of Bi3+ into the TiO2 lattice shifts the absorbance of TiO2 to the visible region then the addition of high adsorption capacity activated charcoal to improve the efficiency of TiO2. AC-Bi/TiO2 is found to be more efficient than Bi/TiO2 and undoped TiO2 for the degradation of MB under solar light irradiation. Surface morphology and bulk composition of the composite was obtained using high resolution-scanning electron microscopy with energy dispersive X-ray analysis. The crystal structure evolution and elemental composition were analyzed by combining Fourier transform-Raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The ultraviolet-visible (UV-vis) absorption spectra show that the absorption edge for the composite with Bi3+ has red shift as compared with that of undoped TiO2. UV-vis diffuse reflectance spectra demonstrated a decrease in the direct band gap of AC-Bi/TiO2. BET surface area, pore radius and pore volume of the materials were calculated by applying the BET equation to the sorption isotherms. The production of hydroxyl radicals (rad OH) on the surface of solar light irradiated materialswere detected by photoluminescence technique using coumarin as a probe molecule. The mechanism of photocatalytic effect of the AC-Bi/TiO2 was proposed for the degradation of MB under solar light irradiation.

  7. Spacelab Charcoal Analyses

    NASA Technical Reports Server (NTRS)

    Slivon, L. E.; Hernon-Kenny, L. A.; Katona, V. R.; Dejarme, L. E.

    1995-01-01

    This report describes analytical methods and results obtained from chemical analysis of 31 charcoal samples in five sets. Each set was obtained from a single scrubber used to filter ambient air on board a Spacelab mission. Analysis of the charcoal samples was conducted by thermal desorption followed by gas chromatography/mass spectrometry (GC/MS). All samples were analyzed using identical methods. The method used for these analyses was able to detect compounds independent of their polarity or volatility. In addition to the charcoal samples, analyses of three Environmental Control and Life Support System (ECLSS) water samples were conducted specifically for trimethylamine.

  8. Comparing modelled fire dynamics with charcoal records for the Holocene

    NASA Astrophysics Data System (ADS)

    Brücher, Tim; Brovkin, Victor; Kloster, Silvia; Marlon, Jennifer; Power, Mitch

    2014-05-01

    An Earth System model of intermediate complexity, CLIMBER-2, and land surface model JSBACH that includes dynamic vegetation, carbon cycle, and fire regime are used for simulation of natural fire dynamics through the last 8,000 years. To compare the fire model results with the charcoal reconstructions, several output variables of the fire model (burned area, carbon emissions) and several approaches of model output processing are tested. The z-scores out of charcoal dataset have been calculated for the period 8,000 to 200 BP to exclude a period of strong anthropogenic forcing during the last two centuries. The model analysis points mainly to an increasing fire activity during the Holocene for most of the investigated areas, which is in good correspondence to reconstructed fire trends out of charcoal data for most of the tested regions, while for few regions such as Europe the simulated trend and the reconstructed trends are different. The difference between the modeled and reconstructed fire activity could be due to absence of the anthropogenic forcing in the model simulations, but also due to limitations of model assumptions for modeling fire dynamics. For the model trends, the usage of averaging or z-score processing of model output resulted in similar directions of trend. Therefore, the approach of fire model output processing does not effect results of the model-data comparison. Global fire modeling is still in its infancy; improving our representations of fire through validation exercises such as what we present here is thus essential before testing hypotheses about the effects of extreme climate changes on fire behavior and potential feedbacks that result from those changes. Brücher, T., Brovkin, V., Kloster, S., Marlon, J. R., and Power, M. J.: Comparing modelled fire dynamics with charcoal records for the Holocene, Clim. Past Discuss., 9, 6429-6458, doi:10.5194/cpd-9-6429-2013, 2013.

  9. Grain-based activated carbons for natural gas storage.

    PubMed

    Zhang, Tengyan; Walawender, Walter P; Fan, L T

    2010-03-01

    Natural gas has emerged as a potential alternative to gasoline due to the increase in global energy demand and environmental concerns. An investigation was undertaken to explore the technical feasibility of implementing the adsorbed natural gas (ANG) storage in the fuel tanks of motor vehicles with activated carbons from biomass, e.g., sorghum and wheat. The grain-based activated carbons were prepared by chemical activation; the experimental parameters were varied to identify the optimum conditions. The porosity of the resultant activated carbons was evaluated through nitrogen adsorption; and the storage capacity, through methane adsorption. A comparative study was also carried out with commercial activated carbons from charcoal. The highest storage factor attained was 89 for compacted grain-based activated carbons from grain sorghum with a bulk density of 0.65 g/cm(3), and the highest storage factor attained is 106 for compacted commercial activated carbons (Calgon) with a bulk density of 0.70 g/cm(3). The storage factor was found to increase approximately linearly with increasing bulk density and to be independent of the extent of compaction. This implies that the grain-based activated carbons are the ideal candidates for the ANG storage.

  10. VOST charcoal specification study

    SciTech Connect

    Foster, A.L.; Bursey, J.T.

    1995-07-01

    The volatile organic sampling train, SW-846 Method 0030, (VOST) is currently one of the leading methodology`s available for the sampling and analysis of volatile organic hazardous compounds from stationary sources at very low levels. The method does not identify a specific equivalent sorbent, nor the performance specifications which would allow determination of an equivalent. Lot 104 petroleum-based charcoal is no longer commercially available. Laboratories are presently using a wide range of substitutes with varying performance from batch to batch of charcoal. To provide performance specifications and identify a replacement for SKC Lot 104 charcoal, a VOST charcoal specification study was initiated. Performance, cost, ease of handling, and plentiful supply make Anasorb 747 a good choice for replacement of SKX Lot 104.

  11. [Adsorption mechanism of furfural onto modified rice husk charcoals].

    PubMed

    Deng, Yong; Wang, Xianhua; Li, Yunchao; Shao, Jing'ai; Yang, Haiping; Chen, Hanping

    2015-10-01

    To evaluate the absorptive characteristics of furfural onto biomass charcoals derived from rice husk pyrolysis, we studied the information of the structure and surface chemistry properties of the rice husk charcoals modified by thermal treatment under nitrogen and carbon dioxide flow and adsorption mechanism of furfural. The modified samples are labeled as RH-N2 and RH-CO2. Fresh rice husk charcoal sample (RH-450) and modified samples were characterized by elemental analysis, nitrogen adsorption-desorption isotherms, Fourier-transform infrared spectroscopy and Boehm titration. The results show that fresh rice husk charcoal obtained at 450 degrees C had a large number of organic groups on its surface and poor pore structure. After the modification under nitrogen and carbon dioxide flow, oxygenic organics in rice husk charcoals decompose further, leading to the reduction of acidic functional groups on charcoals surface, and the increase of the pyrone structures of the basic groups. Meanwhile, pore structure was improved significantly and the surface area was increased, especially for the micropores. This resulted in the increase of π-π dispersion between the surfaces of rice husk charcoals and furfural molecular. With making comprehensive consideration of π-π dispersion and pore structure, the best removal efficiency of furfural was obtained by rice husk charcoal modified under carbon dioxide flow.

  12. Inhibition of mammalian DNA polymerases and the suppression of inflammatory and allergic responses by tyrosol from used activated charcoal waste generated during sake production.

    PubMed

    Mizushina, Yoshiyuki; Ogawa, Yoshiaki; Onodera, Takefumi; Kuriyama, Isoko; Sakamoto, Yuka; Nishikori, Shu; Kamisuki, Shinji; Sugawara, Fumio

    2014-08-06

    The components adsorbed onto activated charcoal following the fermentation process of the Japanese rice wine "sake" have been studied with the aim of identifying suitable applications for this industrial food waste product. The absorbed materials were effectively extracted from the charcoal, and inhibited the activity of several mammalian DNA polymerases (pols). Subsequent purification of the extract afforded tyrosol [4-(2-hydroxyethyl)phenol] as the active component, which selectively inhibited the activity of 11 mammalian pols with IC50 values in the range of 34.3-46.1 μM. In contrast, this compound did not influence the activities of plant or prokaryotic pols or any of the other DNA metabolic enzymes tested. Tyrosol suppressed both anti-inflammatory and antiallergic effects in vivo, including 12-O-tetradecanoylphorbol-13-acetate-induced inflammatory mouse ear edema, and immunoglobulin E-induced passive cutaneous anaphylactic reaction in mice. These results suggested that this byproduct formed during the sake-brewing process could be used as an anti-inflammatory and/or antiallergic agent.

  13. Production and characterization of activated carbons from cereal grains

    SciTech Connect

    Venkatraman, A.; Walawender, W.P.; Fan, L.T.

    1996-12-31

    The term, activated carbon, is a generic name for a family of carbonaceous materials with well-developed porosities and consequently, large adsorptive capacities. Activated carbons are increasingly being consumed worldwide for environmental applications such as separation of volatiles from bulk gases and purification of water and waste-water streams. The global annual production is estimated to be around 300 million kilograms, with a rate of increase of 7% each year. Activated carbons can be prepared from a variety of raw materials. Approximately, 60% of the activated carbons generated in the United States is produced from coal; 20%, from coconut shells; and the remaining 20% from wood and other sources of biomass. The pore structure and properties of activated carbons are influenced by the nature of the starting material and the initial physical and chemical conditioning as well as the process conditions involved in its manufacture. The porous structures of charcoals and activated carbons obtained by the carbonization of kernels have been characterized.

  14. Activated-charcoal filters: water treatment, pollution control, and industrial applications. January 1970-July 1988 (citations from the US Patent data base). Report for January 1970-July 1988

    SciTech Connect

    Not Available

    1988-08-01

    This bibliography contains citations of selected patents concerning activated-charcoal filters and their applications in water treatment, pollution control, and industrial processes. Filtering methods and equipment for air and water purification, industrial distillation and extraction, industrial leaching, and filtration of toxic gases and pollutants are described. Applications include drinking water purification, filtering beverages, production of polymer materials, solvent and metal recovery, swimming pool filtration, waste conversion, automobile fuel and exhaust systems, and footwear deodorizing. (Contains 129 citations fully indexed and including a title list.)

  15. Activated charcoal filters: Water treatment, pollution control, and industrial applications. (Latest citations from the Patent Bibliographic database with exemplary claims. ) Published Search

    SciTech Connect

    Not Available

    1993-08-01

    The bibliography contains citations of selected patents concerning activated charcoal filters and their applications in water treatment, pollution control, and industrial processes. Filtering methods and equipment for air and water purification, industrial distillation and extraction, industrial leaching, and filtration of toxic materials and contaminants are described. Applications include drinking water purification, filtering beverages, production of polymer materials, solvent and metal recovery, waste conversion, automotive fuel and exhaust systems, swimming pool filtration, tobacco smoke filters, kitchen ventilators, medical filtration treatment, and odor absorbing materials. (Contains 250 citations and includes a subject term index and title list.)

  16. Activated charcoal filters: Water treatment, pollution control, and industrial applications. (Latest citations from the US Patent Bibliographic File with exemplary claims). Published Search

    SciTech Connect

    Not Available

    1994-06-01

    The bibliography contains citations of selected patents concerning activated charcoal filters and their applications in water treatment, pollution control, and industrial processes. Filtering methods and equipment for air and water purification, industrial distillation and extraction, and filtration of toxic materials and contaminants are described. Applications are discussed, including drinking water purification, air and water pollution control, manufacture of industrial materials, materials recovery, waste treatment, automotive fuel and exhaust systems, cigarette filters, ventilation systems, medical filtration, and odor absorbing materials. (Contains a minimum of 125 citations and includes a subject term index and title list.)

  17. Activated charcoal filters: Water treatment, pollution control, and industrial applications. (Latest citations from the US Patent Bibliographic file with exemplary claims). Published Search

    SciTech Connect

    1996-01-01

    The bibliography contains citations of selected patents concerning activated charcoal filters and their applications in water treatment, pollution control, and industrial processes. Filtering methods and equipment for air and water purification, industrial distillation and extraction, and filtration of toxic materials and contaminants are described. Applications are discussed, including drinking water purification, air and water pollution control, manufacture of industrial materials, materials recovery, waste treatment, automotive fuel and exhaust systems, cigarette filters, ventilation systems, medical filtration, and odor absorbing materials. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  18. Effects of historic charcoal burning on soil properties

    NASA Astrophysics Data System (ADS)

    Hirsch, Florian; Schneider, Anna; Raab, Alexandra; Raab, Thomas; Buras, Allan; van der Maaten, Ernst; Takla, Melanie; Räbiger, Christin; Cruz Garcia, Roberto; Wilmking, Martin

    2015-04-01

    In Northeastern Germany the production of ironware between the 16th and 19th century left behind a remarkable amount of charcoal kiln remains. At the study site in the forests north of Cottbus, Rubic Brunic Arenosols are developed on Weichselian glaciofluvial deposits. Remote sensing surveys, underpinned by archaeological studies, show that charcoal was gained from several thousand kilns. The round charcoal kiln remains with inner diameters up to 20 m are smooth platforms elevated a few decimeters higher than the surrounding area. The remaining mounds consist of an about 40 cm thick sheet containing residuals of the charcoal production process such as charcoal fragments, ash but also organic material covering the Rubic Brunic Arenosols. The charcoal kiln remains are distanced only up to 100 m from each other. For the 32 square kilometers large study site, the ground area covered by such charcoal production residuals is about 0.5 square kilometer, i.e. 1.5% of the study area. The charcoal kiln sites are a remarkable carbon accumulator on the sandy parent material. Against this background, we aim to characterize the effects of pyrolysis and the enrichment of carbon, induced by the charcoal production, on soil properties. Field work was done during archaeological rescue excavations on three charcoal kiln relicts having diameters of about 15 m. We applied 150 l of Brilliant Blue solution on six 1 square meter plots (three inside, three outside of the charcoal kiln mound) and afterwards trenched horizontal and vertical profiles for recording the staining patterns. Undisturbed soil samples to study soil micromorphology and further undisturbed samples for characterizing soil physical and hydraulic properties were taken. Outside of the charcoal kiln remain the Brilliant Blue solution drained within less than 10 minutes, whereas on the charcoal kiln remains the draining took between 20 and 40 minutes. Preliminary laboratory analyses underline the findings from the field and

  19. Charcoal in the soil and the Earth System

    NASA Astrophysics Data System (ADS)

    Scott, A. C.

    2012-04-01

    Charcoal occurs in the natural environment as either a result of wildfire or volcanic processes. Charcoal is one of a range of pyrolysis products that may be included in the term black carbon. This paper outlines aspects of charcoal formation (both natural and experimental) and briefly considers the taphonomic processes leading to a final assemblage. This is done using examples from recent fires and through experimentation. In particular, it is shown that the temperature of charcoal formation may influence the rate of subsequent decay. This has significance for biochar studies. While charcoal may remain near the place of it's formation and be buried in soils it still may be affected by physical and chemical changes that result in fragmentation and subsequent loss to the soil. Charcoal may also be washed out of the fire site by overland flow particularly if the rain occurs soon after the fire. Charcoal is abundant in many sedimentary rocks deposited in a wide range of environments, from terrestrial to marine. Charcoal has a long fossil record and is found in rock sequences from the late Silurian onwards. Charcoal provides evidence of the deep time history of wildfire. There is an intimate relationship between the history of oxygen in the atmosphere and periods of extensive wildfires. High atmospheric oxygen levels (around 30%) in the late Palaeozoic and Cretaceous had a profound effect on the Earth System. The use of charcoal for plant evolution studies, fire history studies, vegetation studies, anatomical studies, climate and atmospheric studies and the wider importance of charcoal for the Earth and Biological Sciences will be considered (Scott 2010, Glasspool and Scott in press). Charcoal is information-rich but yet is an under-utilized resource.

  20. Impact of ancient charcoal kilns on chemical properties of several forest soils after 2 centuries

    NASA Astrophysics Data System (ADS)

    Dufey, Joseph; Hardy, Brieuc; Cornelis, Jean-Thomas

    2014-05-01

    Pyrogenic carbon plays a major role in soil biogeochemical processes and carbon budgets. Until the early 19th century, charcoal was the unique combustible used for iron metallurgy in Wallonia (Belgium). Traditional charcoal kilns were built directly in the forest: wood logs were piled into a mound and isolated from air oxygen with a covering of vegetation residues and soil before setting fire, inducing wood pyrolysis. Nowadays, ancient wood-charring platforms are still easy to identify on the forest floor as heightened domes of 10 meters in diameter characterized by a very dark topsoil horizon containing charcoal dust and fragments. Our goal is to assess the effects of wood charring at mound kiln sites on the properties of various forest soil types in Wallonia (Belgium), after two centuries. We sampled soil by horizon in 18 ancient kiln sites to 1.20 meter depth. The adjacent charcoal-unaffected soils were sampled the same way. We also collected recent charcoal fragments and topsoil samples from a still active charcoal kiln located close to Dole (France) to apprehend the evolution of soil properties over time. The pH, total carbon (C) and nitrogen (N) content, available phosphorus (Pav), cation exchange capacity at pH 7 (CEC), exchangeable cations (Ca++, Mg++, K+, Na+) and loss on ignition at 550°C (LI550) were measured on each soil sample. We separated the soil profiles in 5 groups based on the nature of soil substrate and pedogenesis for interpretation of the results. We show that the total carbon stock is significantly increased at kiln sites due to higher C concentrations and greater depth of the organo-mineral horizon. The C/N ratio in charcoal-enriched soil horizons is significantly higher than in the neighboring reference soils but clearly attenuated compared to pure wood-charcoal fragments. The CEC is higher in the charcoal-enriched soil horizons, not only due to higher C concentrations but also to increased CEC by carbon unit at kiln sites. The high

  1. paleofire: An R package to analyse sedimentary charcoal records from the Global Charcoal Database to reconstruct past biomass burning

    NASA Astrophysics Data System (ADS)

    Blarquez, Olivier; Vannière, Boris; Marlon, Jennifer R.; Daniau, Anne-Laure; Power, Mitchell J.; Brewer, Simon; Bartlein, Patrick J.

    2014-11-01

    We describe a new R package, paleofire, for analysis and synthesis of charcoal time series, such as those contained in the Global Charcoal Database (GCD), that are used to reconstruct paleofire activity (past biomass burning). paleofire is an initiative of the Global Paleofire Working Group core team (www.gpwg.org), whose aim is to encourage the use of sedimentary charcoal series to develop regional-to-global syntheses of paleofire activity, and to enhance access to the GCD data by providing a common research framework. Currently, paleofire features are organized into three different parts related to (i) site selection and charcoal series extraction from the GCD; (ii) charcoal data transformation; and (iii) charcoal series compositing and synthesis. We provide a technical description of paleofire and describe some new implementations such as the circular block bootstrap procedure. We tested the software using GCDv3 data from eastern North America, and provide examples of interpreting results of regional and global syntheses.

  2. Determination of trace triclosan in environmental water by microporous bamboo-activated charcoal solid-phase extraction combined with HPLC-ESI-MS.

    PubMed

    Sun, Jing; Yi, Chun-Liang; Zhao, Ru-Song; Wang, Xia; Jiang, Wen-Qiang; Wang, Xi-Kui

    2012-10-01

    A sensitive and efficient analytical method for triclosan (TCS) determination in water, which involves enrichment with bamboo-activated charcoal and detection with HPLC-ESI-MS, was developed. The influence of several operational parameters, including the eluant and its volume, the flow rate, the volume andacidity of the sample, and the amount of bamboo-activated charcoal, were investigated and optimized. Under the optimum conditions, linearity of the method was observed in the range of 0.02-20 μg/L, with correlation coefficients (r(2) ) >0.9990. The limit of detection was 0.002 μg/L based on the ratio of chromatographic signal to baseline noise (S/N = 3). The spiked recoveries of TCS in real water samples were achieved in the range of 97.6-112.5%. The proposed method was applied to analyze TCS in real aqueous samples. All the surface water samples collected in Xiaoqing River had detectable levels of TCS with concentrations of 42-197 ng/L.

  3. Effects of quebracho tannin extract (Schinopsis balansae Engl.) and activated charcoal on nitrogen balance, rumen microbial protein synthesis and faecal composition of growing Boer goats.

    PubMed

    Al-Kindi, Amal; Dickhoefer, Uta; Schlecht, Eva; Sundrum, Albert; Schiborra, Anne

    2016-08-01

    Under irrigated arid conditions, organic fertiliser rich in slowly decomposable nitrogen (N) and carbon (C) is needed for soil fertility maintenance. Feeding ruminants with condensed tannins will lower ruminal protein degradation, reduce urinary N excretion and might increase the faecal fraction of slowly decomposable N. Supplementation with activated charcoal (AC) might enrich manure with slowly degrading C. Therefore, we investigated the effects of feeding quebracho tannin extract (QTE) and AC on the N balance of goats, the efficiency of microbial protein synthesis in the rumen (EMPS) and the composition of faeces. The feeding trial comprised three periods; in each period, 12 male Boer goats (28 ± 3.9 kg live weight) were assigned to six treatments: a Control diet (per kg diet 500 g grass hay and 500 g concentrate) and to further five treatments the Control diet was supplemented with QTE (20 g and 40 g/kg; diets QTE2 and QTE4, respectively), with AC (15 g and 30 g/kg, diets AC1.5 and AC3.0, respectively) and a mixture of QTE (20 g/kg) plus AC (15 g/kg) (diet QTEAC). In addition to the N balance, EMPS was calculated from daily excretions of purine derivatives, and the composition of faecal N was determined. There was no effect of QTE and AC supplementation on the intake of organic matter (OM), N and fibre, but apparent total tract digestibility of OM was reduced (p = 0.035). Feeding QTE induced a shift in N excretion from urine to faeces (p ≤ 0.001) without altering N retention. Total N excretion tended to decrease with QTE treatments (p = 0.053), but EMPS was not different between treatments. Faecal C excretion was higher in QTE and AC treatments (p = 0.001) compared with the Control, while the composition of faecal N differed only in concentration of undigested dietary N (p = 0.001). The results demonstrate that QTE can be included into diets of goats up to 40 g/kg, without affecting N utilisation, but simultaneously increasing the

  4. Charcoal filter testing

    SciTech Connect

    Lyons, J.

    1997-08-01

    In this very brief, informal presentation, a representative of the US Nuclear Regulatory Commission outlines some problems with charcoal filter testing procedures and actions being taken to correct the problems. Two primary concerns are addressed: (1) the process to find the test method is confusing, and (2) the requirements of the reference test procedures result in condensation on the charcoal and causes the test to fail. To address these problems, emergency technical specifications were processed for three nuclear plants. A generic or an administrative letter is proposed as a more permanent solution. 1 fig.

  5. Paracetamol biodegradation by activated sludge and photocatalysis and its removal by a micelle-clay complex, activated charcoal, and reverse osmosis membranes.

    PubMed

    Karaman, Rafik; Khamis, Mustafa; Abbadi, Jehad; Amro, Ahmad; Qurie, Mohannad; Ayyad, Ibrahim; Ayyash, Fatima; Hamarsheh, Omar; Yaqmour, Reem; Nir, Shlomo; Bufo, Sabino A; Scrano, Laura; Lerman, Sofia; Gur-Reznik, Shirra; Dosoretz, Carlos G

    2016-10-01

    Kinetic studies on the stability of the pain killer paracetamol in Al-Quds activated sludge demonstrated that paracetamol underwent biodegradation within less than one month to furnish p-aminophenol in high yields. Characterizations of bacteria contained in Al-Quds sludge were accomplished. It was found that Pseudomonas aeruginosa is the bacterium most responsible for the biodegradation of paracetamol to p-aminophenol and hydroquinone. Batch adsorptions of paracetamol and its biodegradation product (p-aminophenol) by activated charcoal and a composite micelle (octadecyltrimethylammonium)-clay (montmorillonite) were determined at 25°C. Adsorption was adequately described by a Langmuir isotherm, and indicated better efficiency of removal by the micelle-clay complex. The ability of bench top reverse osmosis (RO) plant as well as advanced membrane pilot plant to remove paracetamol was also studied at different water matrixes to test the effect of organic matter composition. The results showed that at least 90% rejection was obtained by both plants. In addition, removal of paracetamol from RO brine was investigated by using photocatalytic processes; optimal conditions were found to be acidic or basic pH, in which paracetamol degraded in less than 5 min. Toxicity studies indicated that the effluent and brine were not toxic except for using extra low energy membrane which displayed a half maximal inhibitory concentration (IC-50) value of 80%.

  6. [Hygienic study of an activated fibrous charcoal material as a sorbing filtering element for drinking water afterpurification].

    PubMed

    Prokopov, V A; Mironets, N V; Gakal, R K; Maktaz, E D; Dugan, A M; Teteneva, I A; Tarabarova, S B; Martyshchenko, N V; Nadvornaia, Zh D

    1993-01-01

    The results of complex toxicological and hygienic study showed that the quality of pipe water filtered through the activated carbonic fibrous material (ACFM) "Dnepr-F" forming a part of absorptive filtering element improved markedly. The content of organic substances decreased drastically as well as that of nitrates and iron. Microbiological indices did not suffer appreciable changes and were within permissible limits. The water filtered through the absorptive element with ACFM had no adverse influence on the organisms of warm-blooded animals. Proceeding from foregoing one can conclude that the "Dnepr-F" may be recommended as a part of absorptive filtering element for the final refinement of drinking water.

  7. Dewatering Peat With Activated Carbon

    NASA Technical Reports Server (NTRS)

    Rohatgi, N. K.

    1984-01-01

    Proposed process produces enough gas and carbon to sustain itself. In proposed process peat slurry is dewatered to approximately 40 percent moisture content by mixing slurry with activated carbon and filtering with solid/liquid separation techniques.

  8. Density and porosity as controls on charcoal storage in soils

    NASA Astrophysics Data System (ADS)

    Masiello, C. A.; Liu, Z.; Ziegelgruber, K. L.; Dugan, B.; Gonnermann, H.; Chuang, V. J.; Zygourakis, K.

    2012-04-01

    A number of studies have documented very low biotic and abiotic decomposition rates of charcoal in the environment, leading to the assumption that it stays within soils after deposition. This assumption forms one tenet of a promising carbon sequestration technique, soil biochar amendment. Laboratory and greenhouse trials with biochar (charcoal produced for addition to soil) do show that charcoal remains in soils after amendment. However, when charcoal has been added to soils in field trials, its retention rate in soils is highly variable. Low retention rates have been reported in some environments, leading to questions about its physical movement across landscapes. Density and porosity are fundamental physical characteristics that play a key role in determining charcoal soil residence time. Measuring the density of charcoal has been challenging historically because of its very high porosity (approaching 80%), making standard fluid displacement methods of density measurement error-prone. Here we review techniques available to measure the density and porosity of BC, focusing on two measurements: skeletal density (the density of the solid component of BC), and envelope density (the mass of a BC sample divided by the volume of its exterior envelope). We present skeletal and envelope density data for environmental charcoal samples and for a series of laboratory-produced charcoals, showing that the skeletal density of charcoal is significantly greater than 1.0 g/cc, while the envelope density is significantly less than 1.0 g/cc. This difference means that pore connectivity and pore structure will be important to quantify to understand landscape movement of charcoal.

  9. Water Extracts of Soot and Aged Charcoal as Important Sources of Black Carbon in Estuarine DOM, Determined by Electrospray Ionization (ESI) with Ultrahigh Resolution Fourier Transform Mass Spectrometry (FTMS)

    NASA Astrophysics Data System (ADS)

    Hatcher, P. G.

    2006-12-01

    Despite the quantity of dissolved organic matter (DOM) present in atmospheric precipitation, much of this material remains uncharacterized and yet it's contribution to the black carbon content of DOM in watersheds could be significant due to its origin from atmospheric soot. Also, significant to the source of black carbon in estuarine DOM is water extracts of aged charcoal from forest fires. Using ESI coupled to FTMS we have been successful in linking atmospheric DOM and aged charcoal extracts to riverine DOM. With the ultrahigh mass resolution and accuracy of FTMS, a large series of peaks with unique molecular formulas linked to black carbon can be identified. The various DOM samples extracted by C18 sorption (in methanol: water) were analyzed by 9.4 Tesla ESI FTMS system at the National High Magnetic Field Laboratory in Florida State University (Tallahassee, FL, USA) and a 12Tesla Bruker Apex Qe system at Old Dominion University. Identifying more than 80 % of the thousands of peaks detected, we have demonstrated that ESI FTMS is the most promising analytical technique in analysis of black carbon in DOM. Plotting the elemental compositions of the identified peaks on a Van Krevelen Diagram (molar H/C vs molar O/C vs molar S/C or N/C, we can recognize multiple groups of related compounds. One group that stands out quite visibly is the group of compounds that exhibit a great deal of hydrogen deficiency and appear to be related to soot or black carbon. Many of these compounds from soot are rich in nitrogen and sulfur atoms, indicating a propensity to exist as heteroatomic species, most likely heterocycles. The high degree of unsaturation is associated with condensed aromatic moieties that constitute a large fraction of identified species in soot and charcoal extracts. Other components identified appear to be similar to those observed in natural DOM in riverine samples, probably related to humic-like substances. Lipid-like subtances related to fatty acids also

  10. Production of Charcoals from Cultural Waste of Mushroom and Soybean Hull

    NASA Astrophysics Data System (ADS)

    Inoue, Yoshiki; Miyamoto, Kazumichi; Machida, Hiroshi; Sasaki, Takeru; Horikoshi, Kenichi; Okamoto, Masashi

    In order to utilize cultural waste of mushroom and soybean hull as coke, conversion from dry cultural waste of mushroom (DCWM) and soybean hull (SH) into charcoal by carbonization at 400-800°C, and conversion from them into formed charcoal were investigated. The thermogravimetry tendency of DCWM was intermediate between xylan and lignin, and that of SH was intermediate between cellulose and xylan. Carbonization of DCWM and SH led to make charcoal with high carbon content and higher heating value than raw material. Regarding charcoal carbonized at 800°C, carbon contents of DCWM and SH were 56 and 72%, higher heating values of them were 20.59 and 25.52 MJ/kg, respectively. It was affected by high ash content of DCWM and SH, that carbon contents and higher heating values of these charcoals were lower than coke. On utilization charcoal of DCWM and SH as coke, a preventative method must be taken regarding lower heating value of these than coke. By hot-press forming at 160°C 98MPa from charcoal carbonized at 250°C of DCWM or SH, these charcoal pellets could be produced. And by carbonization at 300-800°C of the pellet formed at 70°C 98MPa from DCWM, carbonized pellet could be produced. In the same manner for producing carbonized pellet of DCWM, the carbonized pellet of SH could be produced, but maximum temperature of carbonization was about 400°C, from the phenomena that puff occur on the pellet in the process of carbonization of it at 500°C. From these results, it is considered effective for increasing energy density of biomass, to convert from raw material into charcoal or formed charcoal.

  11. Fusion reactor high vacuum pumping: Charcoal cryosorber tritium exposure results

    SciTech Connect

    Sedgley, D.W.; Walthers, C.R.; Jenkins, E.M. )

    1991-01-01

    Recent experiments, have shown the practically of using activated charcoal (coconut charcoal) at 4{degrees}K to pump helium and hydrogen isotopes for a fusion reactor. Both speed and capacity for deuterium/helium and tritium/helium-3 mixtures were shown to be satisfactory. The long term effects of tritium on the charcoal/cement system developed by Grumman and LLNL were not known and a program was undertaken to see what, if any, effect long term tritium exposure has on the cryosorber. Several charcoal on aluminum test samples were subjected to six months exposure of tritium at approximately 77{degrees}K. The tritium was scanned several times with a residual gas analyzer and the speed-capacity performance of the samples was measured before, approximately half way through and after the exposure. Modest effects were noted which would not seriously restrict charcoal's use as a cryosorber for fusion reactor high vacuum pumping applications. 4 refs., 8 figs.

  12. Charcoal Regeneration - Part 2. Modified Carbon Surface Activity and Reversibility of TNT Adsorption

    DTIC Science & Technology

    1980-07-01

    Table A-i. Small columna adsorption/desorption cycling as a function of particle size of FS300. o... . . ~Cumulative TNT b Volume Retained, m Effluent, mg...1.4 cm h/in; adsorption from aqueous solution, desorption with acet-,ne. 37 A, Table A-2. Small columna adsorption/desorption cycling as a function of...aqueous solution, desorption with acetone. 38 r ............................................ Table A-2. Small columna adsorption/desorption cycling as a

  13. RECYCLE AND REUSE OF CHARCOAL MADE FROM EXCESS SLUDGE IN MEMBRANE BIOREACTOR

    NASA Astrophysics Data System (ADS)

    Tran, Tuyet Thi; Shafiquzzaman, Md.; Nakajima, Jun

    Charcoal produced from excess sludge appeared to be useful for removing SMP (soluble microbial products) in MBR (membrane bioreactors) and therefore for reducing membrane fouling. Batch experiments and long-term MBR experiments were performed by using charcoal made of actual excess sludge. In the batch experiments, SMP was removed effectively through charcoal addition. This approach proved especially effective for the removal of carbohydrate. Charcoal would serve as an absorbent and coagulant in SMP removal. High BOD (biochemical oxygen demand) removal efficiencies produced no negative effects on biological activity in the reactors during the long-term MBR experiments involving charcoal addition. The decrease of humic substances and COD (chemical oxygen demand) through charcoal addition suggested that this approach effectively enhanced the performance of activated sludge treatment. A charcoal addition of more than 0.1% in long-term MBR experiments effectively decreased the membrane fouling frequency. The use of charcoal therefore served to mitigate membrane fouling. A decrease in carbohydrate, corresponding to the increase in the mean fouling period, suggested that a charcoal addition of more than 0.1% effectively removed SMP, especially carbohydrate. A charcoal cyclic reuse system is also proposed. This system would involve charcoal production and charcoal addition to MBR.

  14. Tubular bamboo charcoal for anode in microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Li, Jun; Ye, Dingding; Zhu, Xun; Liao, Qiang; Zhang, Biao

    2014-12-01

    The anode material plays a significant role in determining the performance of microbial fuel cells (MFCs). In this study, the bamboo charcoal tube is proposed as a novel anode substrate by carbonizing the natural bamboo. Its surface functional groups, biocompatibility and internal resistance are thoroughly investigated. Performance of the MFCs with a conventional graphite tube anode and a bamboo charcoal tube anode is also compared. The results indicate that the tubular bamboo charcoal anode exhibits advantages over the graphite tube anode in terms of rougher surface, superior biocompatibility and smaller total internal resistance. Moreover, the X-ray photoelectron spectroscopy (XPS) analysis for the bamboo charcoal reveals that the introduced C-N bonds facilitate the electron transfer between the biofilm and electrodes. As a result, the MFC with a bamboo charcoal tube anode achieves a 50% improvement in the maximum power density over the graphite tube case. Furthermore, scale-up of the bamboo charcoal tube anode is demonstrated by employing a bundle of tubular bamboo charcoal to reach higher power output.

  15. Preparation of Paper Containing Activated Carbon.

    DTIC Science & Technology

    1984-06-01

    development of charcoal paper. RESUME On a obtenu du papier contenant du charbon actif en dispersant du charbon r~duit en poudre et en versant des agents de...sa capaciti d’adsorption et de ritention du charbon . Ce papier pourrait servir d𔄀crans dans une salle de contr~le de contamination pour le balayage...contenant du charbon . "l-ii:: . ---:.-o * *** * *. .. t C Cd. .. . . . . . . . . . . . . . . . . . . . . . . . . . . 1 S 2 INTRODUCTION . Activated

  16. Factors affecting the adsorption of xenon on activated carbon

    SciTech Connect

    Underhill, D.W.; DiCello, D.C.; Scaglia, L.A.; Watson, J.A.

    1986-08-01

    The presence of water vapor was found to interfere strongly with the dynamic adsorption of /sup 133/Xe on coconut-base activated charcoal. The percent loss in the xenon adsorption coefficient was similar to values reported earlier for the adsorption of krypton on humidified charcoal. Attempts to increase the adsorption of xenon by (a) using a petroleum-based adsorbent with an extremely high surface area and (b) by impregnation of the adsorbent with iodine were not successful.

  17. How surface fire in Siberian Scots pine forests affects soil organic carbon in the forest floor: Stocks, molecular structure, and conversion to black carbon (charcoal)

    NASA Astrophysics Data System (ADS)

    Czimczik, Claudia I.; Preston, Caroline M.; Schmidt, Michael W. I.; Schulze, Ernst-Detlef

    2003-03-01

    In boreal forests, fire is a frequent disturbance and converts soil organic carbon (OC) to more degradation-resistant aromatic carbon, i.e., black carbon (BC) which might act as a long-term atmospheric-carbon sink. Little is known on the effects of fires on boreal soil OC stocks and molecular composition. We studied how a surface fire affected the composition of the forest floor of Siberian Scots pine forests by comparing the bulk elemental composition, molecular structure (13C-MAS NMR), and the aromatic carbon fraction (BC and potentially interfering constituents like tannins) of unburned and burned forest floor. Fire reduced the mass of the forest floor by 60%, stocks of inorganic elements (Si, Al, Fe, K, Ca, Na, Mg, Mn) by 30-50%, and of OC, nitrogen, and sulfur by 40-50%. In contrast to typical findings from temperate forests, unburned OC consisted mainly of (di-)O-alkyl (polysaccharides) and few aromatic structures, probably due to dominant input of lichen biomass. Fire converted OC into alkyl and aromatic structures, the latter consisting of heterocyclic macromolecules and small clusters of condensed carbon. The small cluster size explained the small BC concentrations determined using a degradative molecular marker method. Fire increased BC stocks (16 g kg-1 OC) by 40% which translates into a net-conversion rate of 0.7% (0.35% of net primary production) unburned OC to BC. Here, however, BC was not a major fraction of soil OC pool in unburned or burned forest floor, either due to rapid in situ degradation or relocation.

  18. Interaction mechanisms of organic contaminants with burned straw ash charcoal.

    PubMed

    Huang, Wenhai; Chen, Baoliang

    2010-01-01

    Black carbons (e.g., charcoal) have a great impact on the transport of organic contaminants in soil and water because of its strong affinity and ubiquity in the environment. To further elucidate their interaction mechanism, sorption of polar (p-nitrotoluene, m-dinitrobenzene and nitrobenzene) and nonpolar (naphthalene) aromatic contaminants to burned straw ash charcoal under different de-ashed treatments were investigated. The sorption isotherms fitted well with Freundlich equation, and the Freundlich N values were all around 0.31-0.38, being independent of the sorbate properties and sorbent types. After sequential removal of ashes by acid treatments (HCl and HCl-HF), both adsorption and partition were enhanced due to the enrichment of charcoal component. The separated contribution of adsorption and partition to total sorption were quantified. The effective carbon content in ash charcoal functioned as adsorption sites, partition phases, and hybrid regions with adsorption and partition were conceptualized and calculated. The hybrid regions increased obviously after de-ashed treatment. The linear relationships of Freundlich N values with the charring-temperature of charcoal or biochar (the charred byproduct in biomass pyrolysis) were observed based on the current study and the cited publications which included 15 different temperatures (100-850 degrees C), 10 kinds of precursors of charcoal/biochar, and 10 organic sorbates.

  19. Fire history reconstruction in grassland ecosystems: amount of charcoal reflects local area burned

    NASA Astrophysics Data System (ADS)

    Leys, Bérangère; Brewer, Simon C.; McConaghy, Scott; Mueller, Joshua; McLauchlan, Kendra K.

    2015-11-01

    Fire is one of the most prevalent disturbances in the Earth system, and its past characteristics can be reconstructed using charcoal particles preserved in depositional environments. Although researchers know that fires produce charcoal particles, interpretation of the quantity or composition of charcoal particles in terms of fire source remains poorly understood. In this study, we used a unique four-year dataset of charcoal deposited in traps from a native tallgrass prairie in mid-North America to test which environmental factors were linked to charcoal measurements on three spatial scales. We investigated small and large charcoal particles commonly used as a proxy of fire activity at different spatial scales, and charcoal morphotypes representing different types of fuel. We found that small (125-250 μm) and large (250 μm-1 mm) particles of charcoal are well-correlated (Spearman correlation = 0.88) and likely reflect the same spatial scale of fire activity in a system with both herbaceous and woody fuels. There was no significant relationship between charcoal pieces and fire parameters <500 m from the traps. Moreover, local area burned (<5 km distance radius from traps) explained the total charcoal amount, and regional burning (200 km radius distance from traps) explained the ratio of non arboreal to total charcoal (NA/T ratio). Charcoal variables, including total charcoal count and NA/T ratio, did not correlate with other fire parameters, vegetation cover, landscape, or climate variables. Thus, in long-term studies that involve fire history reconstructions, total charcoal particles, even of a small size (125-250 μm), could be an indicator of local area burned. Further studies may determine relationships among amount of charcoal recorded, fire intensity, vegetation cover, and climatic parameters.

  20. Decolorization of crude latex by activated charcoal, purification and physico-chemical characterization of religiosin, a milk-clotting serine protease from the latex of Ficus religiosa.

    PubMed

    Kumari, Moni; Sharma, Anurag; Jagannadham, M V

    2010-07-14

    The crude latex of Ficus religiosa is decolorized by activated charcoal. Decolorization follows the Freundlich and Langmuir equations. A serine protease, named religiosin, has been purified to homogeneity from the decolorized latex using anion exchange chromatography. Religiosin is a glycoprotein with a molecular mass of 43.4 kDa by MALDI-TOF. Religiosin is an acidic protein with a pI value of 3.8 and acts optimally at pH 8.0-8.5 and temperature 50 degrees C. The proteolytic activity of religiosin is strongly inhibited by PMSF and chymostatin indicating that the enzyme is a serine protease. The extinction coefficient (epsilon(1%)(280)) of religiosin is 29.47 M(-1) cm(-1)with 16 tryptophan, 26 tyrosine, and 11 cysteine residues per molecule. The enzyme shows broad substrate specificity against natural as well as synthetic substrates with an apparent K(m) of 0.066 mM and 6.25 mM using casein and Leu-pNA, respectively. MS/MS analysis confirms the novelty of the enzyme. Religiosin is highly stable against denaturants, metal ions, and detergents as well as over a wide range of pH and temperature. In addition, the enzyme exhibits milk-clotting as well as detergent activity.

  1. Electrosorption and photocatalytic one-stage combined process using a new type of nanosized TiO₂/activated charcoal plate electrode.

    PubMed

    Ayoubi-Feiz, Baharak; Aber, Soheil; Khataee, Alireza; Alipour, Esmaeel

    2014-01-01

    In the present study, an activated charcoal (AC) plate was prepared by physical activation method. Its surface was coated with TiO₂ nanoparticles by electrophoretic deposition (EPD) method. The average crystallite size of TiO₂ nanoparticles was determined approximately 28 nm. The nature of prepared electrode was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area measurement before and after immobilization. The electrosorption and photocatalytic one-stage combined process was investigated in degradation of Lanasol Red 5B (LR5B), and the effect of dye concentration, electrolyte concentration, pH, voltage, and contact time was optimized and modeled using response surface methodology (RSM) approach. The dye concentration of 30 mg L(-1), Na₂SO₄ concentration of 4.38 g L(-1), pH of 4, voltage of 250 mV, and contact time of 120 min were determined as optimum conditions. Decolorization efficiency increased in combined process to 85.65% at optimum conditions compared to 66.03% in TiO₂/AC photocatalytic, 20.09% in TiO₂/AC electrosorption, and 1.91% in AC photocatalytic processes.

  2. Separating proteins with activated carbon.

    PubMed

    Stone, Matthew T; Kozlov, Mikhail

    2014-07-15

    Activated carbon is applied to separate proteins based on differences in their size and effective charge. Three guidelines are suggested for the efficient separation of proteins with activated carbon. (1) Activated carbon can be used to efficiently remove smaller proteinaceous impurities from larger proteins. (2) Smaller proteinaceous impurities are most efficiently removed at a solution pH close to the impurity's isoelectric point, where they have a minimal effective charge. (3) The most efficient recovery of a small protein from activated carbon occurs at a solution pH further away from the protein's isoelectric point, where it is strongly charged. Studies measuring the binding capacities of individual polymers and proteins were used to develop these three guidelines, and they were then applied to the separation of several different protein mixtures. The ability of activated carbon to separate proteins was demonstrated to be broadly applicable with three different types of activated carbon by both static treatment and by flowing through a packed column of activated carbon.

  3. Comparison of activated charcoal and sodium polystyrene sulfonate resin efficiency on reduction of amitriptyline oral absorption in rat as treatments for overdose and toxicities

    PubMed Central

    Yousefi, Gholamhossein; Bizhani, Mohammad; Jamshidzadeh, Akram; Gholamzadeh, Saeid

    2017-01-01

    Objective(s): Comparative in vivo studies were carried out to determine the adsorption characteristics of amitriptyline (AMT) on activated charcoal (AC) and sodium polystyrene sulfonate (SPS). AC has been long used as gastric decontamination agent for tricyclic antidepressants and SPS has showed to be highly effective on in-vitro drugs adsorption. Materials and Methods: Sprague-Dawley male rats were divided into six groups. Group I: control, group II: AMT 200 mg/kg as single dose orally, group III and IV: AC 1g/kg as single dose orally 5 and 30 min after AMT administration respectively, and group 5 and 6: SPS 1 g/kg as single dose orally 5 and 30 min after AMT administration, respectively. 60 min after oral administration of AMT (Tmax of AMT determined in rats), Cmax plasma levels were determined by a validated GC-Mass method. Results: The Cmax values for groups II to IV were determined as 1.1, 0.5, 0.6, 0.1 and 0.3 µg/ml, respectively. Conclusion: AC and SPS could significantly reduce Cmax of AMT when administrated either 5 or 30 min after AMT overdose (P<0.05). However, SPS showed to be more effective than AC in reducing Cmax when was administrated immediately (5 min) after AMT overdose. The results suggest a more efficient alternative to AC for AMT and probably other TCA overdoses. PMID:28133524

  4. Chemical analysis and potential health risks of hookah charcoal.

    PubMed

    Elsayed, Yehya; Dalibalta, Sarah; Abu-Farha, Nedal

    2016-11-01

    Hookah (waterpipe) smoking is a very common practice that has spread globally. There is growing evidence on the hazardous consequences of smoking hookah, with studies indicating that its harmful effects are comparable to cigarette smoking if not worse. Charcoal is commonly used as a heating source for hookah smoke. Although charcoal briquettes are thought to be one of the major contributors to toxicity, their composition and impact on the smoke generated remains largely unidentified. This study aims to analyze the elemental composition of five different raw synthetic and natural charcoals by using Carbon-Hydrogen-Nitrogen (CHN) analysis, inductively coupled plasma (ICP), and scanning electron microscopy coupled with energy dispersive X-Ray spectrometry (SEM-EDS). Elemental analysis showed that the raw charcoals contain heavy metals such as zinc, iron, cadmium, vanadium, aluminum, lead, chromium, manganese and cobalt at concentrations similar, if not higher than, cigarettes. In addition, thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) was used to analyze the chemical composition of the smoke produced from burning the charcoal samples. The smoke emitted from charcoal was found to be the source of numerous compounds which could be hazardous to health. A total of seven carcinogens, 39 central nervous system depressants and 31 respiratory irritants were identified.

  5. Attenuation of polychlorinated biphenyl sorption to charcoal by humic acids.

    PubMed

    Koelmans, Albert A; Meulman, Brendo; Meijer, Thijs; Jonker, Michiel T O

    2009-02-01

    Strong sorption to black carbon may limit the environmental risks of organic pollutants, but interactions with cosorbing humic acid (HA) may interfere. We studied the attenuative effect of HA additions on the sorption of polychlorinated biphenyls (PCBs) to a charcoal. "Intrinsic" sorption to HA-amended charcoal was calculated by subtracting the sorption contribution of HA from the total sorption to charcoal and HA. Association of PCBs with HA was proportional to hydrophobicity. However, the planar PCBs 77 and 126 had an additional 2-4 times stronger association than expected from hydrophobicity alone. Sorption isotherms for the raw charcoal fitted slightly better to a three-parameter Polanyi-Dubinin-Manes model than to a two-parameter Langmuir model. Preloading the charcoal with 1-75 mg of HA/g of charcoal increasingly attenuated sorption to charcoal with up to a factor of 10. The resultant isotherms could be described adequately with the Freundlich model. Isotherm nonlinearity increased with HA loading, suggesting increased sorption competition between HA and PCBs. Attenuation was negligible in the PCB picogram per liter to nanogram per liter range and increased at higher PCB concentrations, which points to saturation of binding sites on the charcoal. Attenuation was highest for planar congeners, which suggests an additional site blockage mechanism. These variations due to HA loading and PCB concentration can explain the variability in attenuation reported in earlier work and imply that the use of constant "attenuation factors" to adjust sorption coefficients determined for pure carbonaceous materials in order to apply them to field situations may not be warranted.

  6. Global charcoal mobilization from soils via dissolution and riverine transport to the oceans.

    PubMed

    Jaffé, Rudolf; Ding, Yan; Niggemann, Jutta; Vähätalo, Anssi V; Stubbins, Aron; Spencer, Robert G M; Campbell, John; Dittmar, Thorsten

    2013-04-19

    Global biomass burning generates 40 million to 250 million tons of charcoal every year, part of which is preserved for millennia in soils and sediments. We have quantified dissolution products of charcoal in a wide range of rivers worldwide and show that globally, a major portion of the annual charcoal production is lost from soils via dissolution and subsequent transport to the ocean. The global flux of soluble charcoal accounts to 26.5 ± 1.8 million tons per year, which is ~10% of the global riverine flux of dissolved organic carbon (DOC). We suggest that the mobilization of charcoal and DOC out of soils is mechanistically coupled. This study closes a major gap in the global charcoal budget and provides critical information in the context of geoengineering.

  7. Characterization and Properties of Activated Carbon Prepared from Tamarind Seeds by KOH Activation for Fe(III) Adsorption from Aqueous Solution.

    PubMed

    Mopoung, Sumrit; Moonsri, Phansiri; Palas, Wanwimon; Khumpai, Sataporn

    2015-01-01

    This research studies the characterization of activated carbon from tamarind seed with KOH activation. The effects of 0.5 : 1-1.5 : 1 KOH : tamarind seed charcoal ratios and 500-700°C activation temperatures were studied. FTIR, SEM-EDS, XRD, and BET were used to characterize tamarind seed and the activated carbon prepared from them. Proximate analysis, percent yield, iodine number, methylene blue number, and preliminary test of Fe(III) adsorption were also studied. Fe(III) adsorption was carried out by 30 mL column with 5-20 ppm Fe(III) initial concentrations. The percent yield of activated carbon prepared from tamarind seed with KOH activation decreased with increasing activation temperature and impregnation ratios, which were in the range from 54.09 to 82.03 wt%. The surface functional groups of activated carbon are O-H, C=O, C-O, -CO3, C-H, and Si-H. The XRD result showed high crystallinity coming from a potassium compound in the activated carbon. The main elements found in the activated carbon by EDS are C, O, Si, and K. The results of iodine and methylene blue adsorption indicate that the pore size of the activated carbon is mostly in the range of mesopore and macropore. The average BET pore size and BET surface area of activated carbon are 67.9764 Å and 2.7167 m(2)/g, respectively. Finally, the tamarind seed based activated carbon produced with 500°C activation temperature and 1.0 : 1 KOH : tamarind seed charcoal ratio was used for Fe(III) adsorption test. It was shown that Fe(III) was adsorbed in alkaline conditions and adsorption increased with increasing Fe(III) initial concentration from 5 to 20 ppm with capacity adsorption of 0.0069-0.019 mg/g.

  8. URINARY MUTAGENICITY IN CHARCOAL WORKERS: A CROSS-SECTIONAL STUDY IN NORTHEASTERN BRAZIL

    EPA Science Inventory

    Urinary Mutagenicity in charcoal workers: a cross-sectional study in northeastern Brazil

    Charcoal production by wood carbonization is an ancient process that has changed little since the Bronze Age. Its production in large scale is necessary to sustain some steel and pig...

  9. Biological activation of carbon filters.

    PubMed

    Seredyńska-Sobecka, Bozena; Tomaszewska, Maria; Janus, Magdalena; Morawski, Antoni W

    2006-01-01

    To prepare biological activated carbon (BAC), raw surface water was circulated through granular activated carbon (GAC) beds. Biological activity of carbon filters was initiated after about 6 months of filter operation and was confirmed by two methods: measurement of the amount of biomass attached to the carbon and by the fluorescein diacetate (FDA) test. The effect of carbon pre-washing on WG-12 carbon properties was also studied. For this purpose, the nitrogen adsorption isotherms at 77K and Fourier transform-infrared (FT-IR) spectra analyses were performed. Moreover, iodine number, decolorizing power and adsorption properties of carbon in relation to phenol were studied. Analysis of the results revealed that after WG-12 carbon pre-washing its BET surface increased a little, the pH value of the carbon water extract decreased from 11.0 to 9.4, decolorizing power remained at the same level, and the iodine number and phenol adsorption rate increased. In preliminary studies of the ozonation-biofiltration process, a model phenol solution with concentration of approximately 10mg/l was applied. During the ozonation process a dose of 1.64 mg O(3)/mg TOC (total organic carbon) was employed and the contact time was 5 min. Four empty bed contact times (EBCTs) in the range of 2.4-24.0 min were used in the biofiltration experiment. The effectiveness of purification was measured by the following parameters: chemical oxygen demand (COD(Mn)), TOC, phenol concentration and UV(254)-absorbance. The parameters were found to decrease with EBCT.

  10. Activated carbon to the rescue

    SciTech Connect

    Sen, S.

    1996-03-01

    This article describes the response to pipeline spill of ethylene dichloride (EDC) on the property of an oil company. Activated carbon cleanup proceedure was used. During delivery, changeout, transport, storage, thermal reactivation, and return delivery to the site, the carbon never came into direct contact with operating personnel or the atmosphere. More than 10,000 tones of dredge soil and 50 million gallons of surface water were processed during the emergency response.

  11. Activated charcoal-mediated RNA extraction method for Azadirachta indica and plants highly rich in polyphenolics, polysaccharides and other complex secondary compounds

    PubMed Central

    2013-01-01

    Background High quality RNA is a primary requisite for numerous molecular biological applications but is difficult to isolate from several plants rich in polysaccharides, polyphenolics and other secondary metabolites. These compounds either bind with nucleic acids or often co-precipitate at the final step and many times cannot be removed by conventional methods and kits. Addition of vinyl-pyrollidone polymers in extraction buffer efficiently removes polyphenolics to some extent, but, it failed in case of Azadirachta indica and several other medicinal and aromatic plants. Findings Here we report the use of adsorption property of activated charcoal (0.03%–0.1%) in RNA isolation procedures to remove complex secondary metabolites and polyphenolics to yield good quality RNA from Azadirachta indica. We tested and validated our modified RNA isolation method across 21 different plants including Andrographis paniculata, Aloe vera, Rosa damascena, Pelargonium graveolens, Phyllanthus amarus etc. from 13 other different families, many of which are considered as tough system for isolating RNA. The A260/280 ratio of the extracted RNA ranged between 1.8-2.0 and distinct 28S and 18S ribosomal RNA bands were observed in denaturing agarose gel electrophoresis. Analysis using Agilent 2100 Bioanalyzer revealed intact total RNA yield with very good RNA Integrity Number. Conclusions The RNA isolated by our modified method was found to be of high quality and amenable for sensitive downstream molecular applications like subtractive library construction and RT-PCR. This modified RNA isolation procedure would aid and accelerate the biotechnological studies in complex medicinal and aromatic plants which are extremely rich in secondary metabolic compounds. PMID:23537338

  12. Baking sunflower hulls within an aluminum envelope in a common laboratory oven yields charcoal

    PubMed Central

    Arnal, Pablo Maximiliano

    2015-01-01

    Charcoals have been widely used by scientist to research the removal of contaminants from water and air. One key feature of charcoal is that it keeps macropores from the parent material – though anisotropically contracted – and can even develop meso- and micropores. However, the controlled thermochemical conversion of biomass into charcoal at laboratory scale normally requires special setups which involve either vacuum or inert gas. Those setups may not be affordable in research groups or educational institutions where the research of charcoals would be highly welcome. In this work, I propose a simple and effective method to steer the thermochemical process that converts sunflower hulls (SFH) into charcoal with basic laboratory resources. The carbonization method: • Place SFH in an airtight aluminum envelope. • Thermally treat SFH within the envelope in a common laboratory oven. • Open the envelope to obtain the carbonized sunflower hulls. PMID:26150989

  13. Baking sunflower hulls within an aluminum envelope in a common laboratory oven yields charcoal.

    PubMed

    Arnal, Pablo Maximiliano

    2015-01-01

    Charcoals have been widely used by scientist to research the removal of contaminants from water and air. One key feature of charcoal is that it keeps macropores from the parent material - though anisotropically contracted - and can even develop meso- and micropores. However, the controlled thermochemical conversion of biomass into charcoal at laboratory scale normally requires special setups which involve either vacuum or inert gas. Those setups may not be affordable in research groups or educational institutions where the research of charcoals would be highly welcome. In this work, I propose a simple and effective method to steer the thermochemical process that converts sunflower hulls (SFH) into charcoal with basic laboratory resources. The carbonization method: •Place SFH in an airtight aluminum envelope.•Thermally treat SFH within the envelope in a common laboratory oven.•Open the envelope to obtain the carbonized sunflower hulls.

  14. Water treatment using activated carbon supporting silver and magnetite.

    PubMed

    Valušová, Eva; Vandžurová, Anna; Pristaš, Peter; Antalík, Marián; Javorský, Peter

    2012-01-01

    Recent efforts in water purification have led to the development of novel materials whose unique properties can offer effective biocidal capabilities with greater ease of use and at lower cost. In this study, we introduce a novel procedure for the preparation of activated carbon (charcoal) composite in which magnetite and silver are incorporated (MCAG); we also describe the use of this material for the disinfection of surface water. The formation process of magnetic MCAG composite was studied using ultraviolet-visible spectroscopy. The results demonstrated the high sorption efficiency of AgNO₃ to magnetic activated carbon. The antimicrobial capabilities of the prepared MCAG were examined and the results clearly demonstrate their inhibitory effect on total river water bacteria and on Pseudomonas koreensis and Bacillus mycoides cultures isolated from river water. The bacterial counts in river water samples were reduced by five orders of magnitude following 30 min of treatment using 1 g l⁻¹ of MCAG at room temperature. The removal of all bacteria from the surface water samples implies that the MCAG material would be a suitable disinfectant for such waters. In combination with its magnetic character, MCAG would be an excellent candidate for the simple ambulatory disinfection of surface water.

  15. The stability and functional properties of charcoal in Ghanaian agriculture

    NASA Astrophysics Data System (ADS)

    Maxfield, Tom; Sohi, Saran

    2014-05-01

    Weathering of biochar will lead to its eventual mineralisation to CO2, but how does this happen and how quickly will the biochar break down? This study focuses on the fate of charcoal, as an analogue for biochar, over a ten year period in rural Ghana. The objectives of the work were to determine the stability of charcoal over this timeframe, the change in its functional properties and to calibrate or validate recently established approaches to age biochar artificially. The study showed that the oxygen-to-carbon ratio of charcoal surfaces generally increases over time. Gradually the oxidation penetrates the subsurface layers, causing surface layers to erode and exposing previously un-aged surfaces to degradation.

  16. Development of charcoal sorbents for helium cryopumping

    SciTech Connect

    Sedgley, D.W.; Tobin, A.G.

    1984-01-01

    Testing of the cryogenically cooled charcoal using fusion-compatible binders for pumping helium has shown promising results. The program demonstrated comparable or improved performance with these binders compared to the charcoal (type and size) using an epoxy binder.

  17. Photoconductivity of activated carbon fibers

    SciTech Connect

    Kuriyama, K.; Dresselhaus, M.S. )

    1990-08-01

    The photoconductivity is measured on a high-surface-area disordered carbon material, namely activated carbon fibers, to investigate their electronic properties. Measurements of decay time, recombination kinetics and temperature dependence of the photoconductivity generally reflect the electronic properties of a material. The material studied in this paper is a highly disordered carbon derived from a phenolic precursor, having a huge specific surface area of 1000--2000m{sup 2}/g. Our preliminary thermopower measurements suggest that this carbon material is a p-type semiconductor with an amorphous-like microstructure. The intrinsic electrical conductivity, on the order of 20S/cm at room temperature, increases with increasing temperature in the range 30--290K. In contrast with the intrinsic conductivity, the photoconductivity in vacuum decreases with increasing temperature. The recombination kinetics changes from a monomolecular process at room temperature to a biomolecular process at low temperatures. The observed decay time of the photoconductivity is {approx equal}0.3sec. The magnitude of the photoconductive signal was reduced by a factor of ten when the sample was exposed to air. The intrinsic carrier density and the activation energy for conduction are estimated to be {approx equal}10{sup 21}/cm{sup 3} and {approx equal}20meV, respectively. The majority of the induced photocarriers and of the intrinsic carriers are trapped, resulting in the long decay time of the photoconductivity and the positive temperature dependence of the conductivity. 54 refs., 11 figs., 3 tabs.

  18. Photoconductivity of Activated Carbon Fibers

    DOE R&D Accomplishments Database

    Kuriyama, K.; Dresselhaus, M. S.

    1990-08-01

    The photoconductivity is measured on a high-surface-area disordered carbon material, namely activated carbon fibers, to investigate their electronic properties. Measurements of decay time, recombination kinetics and temperature dependence of the photoconductivity generally reflect the electronic properties of a material. The material studied in this paper is a highly disordered carbon derived from a phenolic precursor, having a huge specific surface area of 1000--2000m{sup 2}/g. Our preliminary thermopower measurements suggest that this carbon material is a p-type semiconductor with an amorphous-like microstructure. The intrinsic electrical conductivity, on the order of 20S/cm at room temperature, increases with increasing temperature in the range 30--290K. In contrast with the intrinsic conductivity, the photoconductivity in vacuum decreases with increasing temperature. The recombination kinetics changes from a monomolecular process at room temperature to a biomolecular process at low temperatures. The observed decay time of the photoconductivity is {approx equal}0.3sec. The magnitude of the photoconductive signal was reduced by a factor of ten when the sample was exposed to air. The intrinsic carrier density and the activation energy for conduction are estimated to be {approx equal}10{sup 21}/cm{sup 3} and {approx equal}20meV, respectively. The majority of the induced photocarriers and of the intrinsic carriers are trapped, resulting in the long decay time of the photoconductivity and the positive temperature dependence of the conductivity.

  19. The impact of charcoal production on forest degradation: a case study in Tete, Mozambique

    NASA Astrophysics Data System (ADS)

    Sedano, F.; Silva, J. A.; Machoco, R.; Meque, C. H.; Sitoe, A.; Ribeiro, N.; Anderson, K.; Ombe, Z. A.; Baule, S. H.; Tucker, C. J.

    2016-09-01

    Charcoal production for urban energy consumption is a main driver of forest degradation in sub Saharan Africa. Urban growth projections for the continent suggest that the relevance of this process will increase in the coming decades. Forest degradation associated to charcoal production is difficult to monitor and commonly overlooked and underrepresented in forest cover change and carbon emission estimates. We use a multitemporal dataset of very high-resolution remote sensing images to map kiln locations in a representative study area of tropical woodlands in central Mozambique. The resulting maps provided a characterization of the spatial extent and temporal dynamics of charcoal production. Using an indirect approach we combine kiln maps and field information on charcoal making to describe the magnitude and intensity of forest degradation linked to charcoal production, including aboveground biomass and carbon emissions. Our findings reveal that forest degradation associated to charcoal production in the study area is largely independent from deforestation driven by agricultural expansion and that its impact on forest cover change is in the same order of magnitude as deforestation. Our work illustrates the feasibility of using estimates of urban charcoal consumption to establish a link between urban energy demands and forest degradation. This kind of approach has potential to reduce uncertainties in forest cover change and carbon emission assessments in sub-Saharan Africa.

  20. Solvent-regenerated activated carbon

    SciTech Connect

    McLaughlin, H. )

    1988-07-01

    This report summarizes the results of a University/Industry research project, sponsored by the New York State Energy Research and Development Authority and Fluids Design Corporation. The research project studied the solvent regeneration of activated carbon. Activate carbon was used to remove trace organics from aqueous streams, then regenerated by desorbing the adsorbates with organic solvents. The project included a survey of the potential applications in New York State industries, fundamental research on the adsorption/desorption phenomena, and design of a full-scale process. The economics of the full-scale process were evaluated and compared to alternate available technologies. The result of this work is a versatile process with attractive economics. A wide range of adsorbates and solvents were found to be acceptable for this process. The design methodologies are developed and the techniques for evaluating a new application are delineated. 13 refs., 12 figs., 4 tabs.

  1. Modified Activated Carbon Perchlorate Sorbents

    DTIC Science & Technology

    2007-01-25

    nitrosodimethylamine precursors in municipal wastewater treatment plants. Environ. Sci. Technol., 2004. 38: p. 1445-1454. 15. Shmidt, V., K. Rybakov...Engineering and Management, 1994. 141: p. 12. 33. Walker, G. and L. Weatherley, Biological Activated Carbon Treatment of Industrial Wastewater in... Treatment with Ammonia (NAC), Urea-formaldehyde Resin (UAC), and Hydrogen (HAC). Data are Indicated by the Symbol and Least Squares Fit of the Langmuir

  2. Air quality index from charcoal production sites, carboxyheamoglobin and lung function among occupationally exposed charcoal workers in South Western Nigeria.

    PubMed

    Olujimi, O O; Ana, G R E E; Ogunseye, O O; Fabunmi, V T

    2016-01-01

    Charcoal production is often accompanied with gaseous and particulate emission into the atmosphere and occupationally exposed workers could be affected. This cross sectional comparative study was carried out to assess the levels of carbon monoxide (CO), carbon dioxide (CO2), sulphur dioxide (SO2), nitrogen dioxide (NO2) and particulate matter (PM2.5) generated during the phases of charcoal production and their relationship with certain biomarkers among charcoal workers (subjects) and non-charcoal workers (controls) such as carboxyhaemoglobin (COHb), forced expiratory volume in the first second of expiration (FEV1), peak expiratory flow rate (PEFR) and body mass index (BMI) in Igbo-Ora, Oyo State and Alabata, Ogun State, which are two of the major hubs of charcoal production in South Western Nigeria. Four communities in Igbo-Ora and six communities in Alabata were purposively selected and levels of pollutant gases were assessed using appropriate gas meters, PM2.5 was assessed with Thermo Scientific MIE pDR-1500, FEV1 and PEFR were measured with Piko-1 spirometer while COHb was assessed using non-invasive pulse CO-oximeter (Rad 57). Data were statistically analyzed and results were compared with recommended guidelines. The mean FEV1, PEFR, COHb and BMI for subjects and controls were 2.35 ± 0.73 and 2.69 ± 0.56, 253.72 ± 103.45 and 330.02 ± 94.61 (p < 0.01), 13.28 ± 3.91 and 8.50 ± 3.68 (p < 0.01) and 21.97 ± 2.19 and 23.36 ± 3.74 (p < 0.05) respectively. There was a statistically significant difference between actual and expected values of FEV1 (p < 0.01) and PEFR (p < 0.01) among charcoal workers. There existed a positive correlation between CO and COHb while FEV1 and PEFR correlated negatively with PM2.5. The study showed that charcoal workers are exposed to high levels of CO and PM2.5, contributing to lowered respiratory functions for FEV1 and PEFR and high levels of COHb compared to the control group. Routine respiratory and

  3. Charcoal production in the Mopane woodlands of Mozambique: what are the trade-offs with other ecosystem services?

    PubMed Central

    Baumert, Sophia; Vollmer, Frank; Grundy, Isla; Fisher, Janet; Fernando, Jone; Luz, Ana; Lisboa, Sá N.

    2016-01-01

    African woodlands form a major part of the tropical grassy biome and support the livelihoods of millions of rural and urban people. Charcoal production in particular is a major economic activity, but its impact on other ecosystem services is little studied. To address this, our study collected biophysical and social datasets, which were combined in ecological production functions, to assess ecosystem service provision and its change under different charcoal production scenarios in Gaza Province, southern Mozambique. We found that villages with longer histories of charcoal production had experienced declines in wood suitable for charcoal, firewood and construction, and tended to have lower perceived availabilities of these services. Scenarios of future charcoal impacts indicated that firewood and woody construction services were likely to trade-off with charcoal production. However, even under the most extreme charcoal scenario, these services were not completely lost. Other provisioning services, such as wild food, medicinal plants and grass, were largely unaffected by charcoal production. To reduce the future impacts of charcoal production, producers must avoid increased intensification of charcoal extraction by avoiding the expansion of species and sizes of trees used for charcoal production. This is a major challenge to land managers and policymakers in the area. This article is part of the themed issue ‘Tropical grassy biomes: linking ecology, human use and conservation’. PMID:27502380

  4. Activated, coal-based carbon foam

    DOEpatents

    Rogers, Darren Kenneth; Plucinski, Janusz Wladyslaw

    2004-12-21

    An ablation resistant, monolithic, activated, carbon foam produced by the activation of a coal-based carbon foam through the action of carbon dioxide, ozone or some similar oxidative agent that pits and/or partially oxidizes the carbon foam skeleton, thereby significantly increasing its overall surface area and concurrently increasing its filtering ability. Such activated carbon foams are suitable for application in virtually all areas where particulate or gel form activated carbon materials have been used. Such an activated carbon foam can be fabricated, i.e. sawed, machined and otherwise shaped to fit virtually any required filtering location by simple insertion and without the need for handling the "dirty" and friable particulate activated carbon foam materials of the prior art.

  5. Activated, coal-based carbon foam

    SciTech Connect

    Rogers, Darren Kenneth; Plucinski, Janusz Wladyslaw

    2009-06-09

    An ablation resistant, monolithic, activated, carbon foam produced by the activation of a coal-based carbon foam through the action of carbon dioxide, ozone or some similar oxidative agent that pits and/or partially oxidizes the carbon foam skeleton, thereby significantly increasing its overall surface area and concurrently increasing its filtering ability. Such activated carbon foams are suitable for application in virtually all areas where particulate or gel form activated carbon materials have been used. Such an activated carbon foam can be fabricated, i.e. sawed, machined and otherwise shaped to fit virtually any required filtering location by simple insertion and without the need for handling the "dirty" and friable particulate activated carbon foam materials of the prior art.

  6. Could charcoal filtration of cigarette smoke reduce smoking-induced disease? A review of the literature.

    PubMed

    Coggins, Christopher R E; Gaworski, Charles L

    2008-04-01

    A review of the published work with charcoal-filtered cigarettes indicates that there are reductions in the concentrations for many gas-vapor phase constituents found in mainstream smoke. However, charcoal filters provided no apparent capacity for reduction of smoke particulate phase components. The reductions in gas-vapor phase smoke chemistry analytes generally correspond with findings of reduced toxicological activity, principally related to a reduction in the cytotoxic action of the volatile smoke constituents. Results of a short-term clinical study show small reductions in the biomarkers of the gas-vapor phase smoke constituents in subjects smoking charcoal-filtered cigarettes, compared to subjects smoking non-charcoal filtered cigarettes. The very limited epidemiology data (a single study) fail to demonstrate a conclusive beneficial effect of charcoal-filtered cigarette products compared to non-charcoal filtered cigarette products. Review of the scientific literature is hindered due to the lack of documentation regarding the activity of the charcoal used in the filter, and the inconsistency in product designs used between the various different disciplines (chemistry, pre-clinical, clinical and epidemiology) that have conducted studies with charcoal filtered cigarettes. There do not appear to be any published studies using a combination of data from the different disciplines based on a consistently designed charcoal cigarette filter. Although the literature presently available would suggest that smoke filtration provided by current charcoal filter techniques alone may not be substantial enough to reduce smoking-related disease, the data are limited. Therefore, for the reduction of smoking-induced disease, it is difficult to come to a definitive conclusion regarding the potential health benefits of using charcoal as a smoke filtration technology.

  7. Macro-Particle Charcoal C Content following Prescribed Burning in a Mixed-Conifer Forest, Sierra Nevada, California

    PubMed Central

    Wiechmann, Morgan L.; Hurteau, Matthew D.; Kaye, Jason P.; Miesel, Jessica R.

    2015-01-01

    Fire suppression and changing climate have resulted in increased large wildfire frequency and severity in the western United States, causing carbon cycle impacts. Forest thinning and prescribed burning reduce high-severity fire risk, but require removal of biomass and emissions of carbon from burning. During each fire a fraction of the burning vegetation and soil organic matter is converted into charcoal, a relatively stable carbon form. We sought to quantify the effects of pre-fire fuel load and type on charcoal carbon produced by biomass combusted in a prescribed burn under different thinning treatments and to identify more easily measured predictors of charcoal carbon mass in a historically frequent-fire mixed-conifer forest. We hypothesized that charcoal carbon produced from coarse woody debris (CWD) during prescribed burning would be greater than that produced from fine woody debris (FWD). We visually quantified post-treatment charcoal carbon content in the O-horizon and the A-horizon beneath CWD (> 30 cm diameter) and up to 60 cm from CWD that was present prior to treatment. We found no difference in the size of charcoal carbon pools from CWD (treatment means ranged from 0.3–2.0 g m-2 of A-horizon and 0.0–1.7 g m-2 of O-horizon charcoal) and FWD (treatment means ranged from 0.2–1.7 g m-2 of A-horizon and 0.0–1.5 g m-2 of O-horizon charcoal). We also compared treatments and found that the burn-only, understory-thin and burn, and overstory-thin and burn treatments had significantly more charcoal carbon than the control. Charcoal carbon represented 0.29% of total ecosystem carbon. We found that char mass on CWD was an important predictor of charcoal carbon mass, but only explained 18–35% of the variation. Our results help improve our understanding of the effects forest restoration treatments have on ecosystem carbon by providing additional information about charcoal carbon content. PMID:26258533

  8. Macro-particle charcoal C content following prescribed burning in a mixed-conifer forest, Sierra Nevada, California.

    PubMed

    Wiechmann, Morgan L; Hurteau, Matthew D; Kaye, Jason P; Miesel, Jessica R

    2015-01-01

    Fire suppression and changing climate have resulted in increased large wildfire frequency and severity in the western United States, causing carbon cycle impacts. Forest thinning and prescribed burning reduce high-severity fire risk, but require removal of biomass and emissions of carbon from burning. During each fire a fraction of the burning vegetation and soil organic matter is converted into charcoal, a relatively stable carbon form. We sought to quantify the effects of pre-fire fuel load and type on charcoal carbon produced by biomass combusted in a prescribed burn under different thinning treatments and to identify more easily measured predictors of charcoal carbon mass in a historically frequent-fire mixed-conifer forest. We hypothesized that charcoal carbon produced from coarse woody debris (CWD) during prescribed burning would be greater than that produced from fine woody debris (FWD). We visually quantified post-treatment charcoal carbon content in the O-horizon and the A-horizon beneath CWD (> 30 cm diameter) and up to 60 cm from CWD that was present prior to treatment. We found no difference in the size of charcoal carbon pools from CWD (treatment means ranged from 0.3-2.0 g m-2 of A-horizon and 0.0-1.7 g m-2 of O-horizon charcoal) and FWD (treatment means ranged from 0.2-1.7 g m-2 of A-horizon and 0.0-1.5 g m-2 of O-horizon charcoal). We also compared treatments and found that the burn-only, understory-thin and burn, and overstory-thin and burn treatments had significantly more charcoal carbon than the control. Charcoal carbon represented 0.29% of total ecosystem carbon. We found that char mass on CWD was an important predictor of charcoal carbon mass, but only explained 18-35% of the variation. Our results help improve our understanding of the effects forest restoration treatments have on ecosystem carbon by providing additional information about charcoal carbon content.

  9. Comparing the desorption and biodegradation of low concentrations of phenanthrene sorbed to activated carbon, biochar and compost.

    PubMed

    Marchal, Geoffrey; Smith, Kilian E C; Rein, Arno; Winding, Anne; Trapp, Stefan; Karlson, Ulrich G

    2013-02-01

    Carbonaceous soil amendments are applied to contaminated soils and sediments to strongly sorb hydrophobic organic contaminants (HOCs) and reduce their freely dissolved concentrations. This limits biouptake and toxicity, but also biodegradation. To investigate whether HOCs sorbed to such amendments can be degraded at all, the desorption and biodegradation of low concentrations of (14)C-labelled phenanthrene (≤5 μg L(-1)) freshly sorbed to suspensions of the pure soil amendments activated carbon (AC), biochar (charcoal) and compost were compared. Firstly, the maximum abiotic desorption of phenanthrene from soil amendment suspensions in water, minimal salts medium (MSM) or tryptic soy broth (TSB) into a dominating silicone sink were measured. Highest fractions remained sorbed to AC (84±2.3%, 87±4.1%, and 53±1.2% for water, MSM and TSB, respectively), followed by charcoal (35±2.2%, 32±1.7%, and 12±0.3%, respectively) and compost (1.3±0.21%, similar for all media). Secondly, the mineralization of phenanthrene sorbed to AC, charcoal and compost by Sphingomonas sp. 10-1 (DSM 12247) was determined. In contrast to the amounts desorbed, phenanthrene mineralization was similar for all the soil amendments at about 56±11% of the initially applied radioactivity. Furthermore, HPLC analyses showed only minor amounts (<5%) of residual phenanthrene remaining in the suspensions, indicating almost complete biodegradation. Fitting the data to a coupled desorption and biodegradation model revealed that desorption did not limit biodegradation for any of the amendments, and that degradation could proceed due to the high numbers of bacteria and/or the production of biosurfactants or biofilms. Therefore, reduced desorption of phenanthrene from AC or charcoal did not inhibit its biodegradation, which implies that under the experimental conditions these amendments can reduce freely dissolved concentration without hindering biodegradation. In contrast, phenanthrene sorbed to compost

  10. Time-dependent response of a charcoal bed to radon and water vapor in flowing air

    SciTech Connect

    Henkel, J.A.; Fentiman, A.W.; Blue, T.E.

    1995-12-31

    Extremely high airborne concentrations of radon gas may be encountered during the remediation of uranium mill tailings storage facilities. Radon is also a constituent of the off-gas of mill-tailing vitrification. An effective way to remove radon from either gas is to pass the gas through a packed bed containing activated charcoal. Measurements of radon concentrations in the environment using charcoal canisters were first described by George. Canisters similar to those used by George in his first experiments have become the U.S. Environmental Protection Agency`s (EPA`s) standard for measuring environmental radon and were described in the EPA protocol for environmental radon measurement. The dynamic behavior of EPA charcoal canisters has been previously described with a mathematical model for the kinetics of radon gas adsorption in air in the presence of water vapor. This model for charcoal canisters has been extended to large charcoal beds with flowing air containing radon and water vapor. The mathematical model for large charcoal beds can be used to evaluate proposed bed designs or to model existing beds. Parameters that affect the radon distribution within a charcoal bed that can be studied using the mathematical model include carrier gas relative humidity and flow velocity, and input radon concentration. In addition, the relative performances of several different charcoals can be studied, provided sufficient information about their adsorption, desorption, and diffusion constants is known.

  11. [The effect of the application sorption of a fibrous activated charcoal material with highly dispersed iron on the course of a wound process].

    PubMed

    Symorot, M I; Shvets, T M; Kryzyna, P S; Kushchevs'ka, N F; Denys, R O

    1999-09-01

    Results of the experiments carried out show that the use of the activated carbon fibrous material "Dnipro" for medical purposes (ABBM "Dnipro" MP) and the suspension of high-dispersity iron combined in treatment of infected and suppurating wounds is associated with a more pronounced therapeutical effect than application to the wound surfaces of the standard ABBM "Dnipro" MP. The compositional method using ABBM "Dnipro" MP and high-dispersity iron obtainable by thermochemical techniques has a marked antimicrobial action and stimulates the course of the wound process.

  12. Spatial variation in the charcoal pool

    NASA Astrophysics Data System (ADS)

    Ohlson, M.; Bjune, A. E.; Kasin, I.; Nordtug Wist, A.

    2012-04-01

    Mikael Ohlson, Anne E. Bjune, Isabella Kasin and Anveig Nordtug Wist It is well known that the soil charcoal pool varies significantly in size across different types of forest landscapes and regional climates. However, the level of variation on fine spatial scales within a given forest landscape remains poorly known. Here we use a geostatistical approach to describe the spatial structure and variability of the soil charcoal pool in a boreal forest landscape. Our study landscape is a watershed including a small lake and two distinct types of forests, viz. Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) forests. The study is based on 200 forest soil cores and one lake sediment core in which the amount of macroscopic charcoal was measured. The amount of charcoal in the forest soil cores was very variable and ranged from 0 to 3600 g per square meter. The variation was profound also on fine spatial scales, i.e. 0.05 - 0.2 m, and geostatistical analysis revealed only weak spatial structuring on scales from 0.05 up to 200 m. Although weak spatial structuring, there were three significant and general patterns in the soil charcoal pool. First, there was a positive relationship between the amount of charcoal in the soil and the density of the contemporary forest. Second, there was more charcoal in the spruce forest than in the pine forest. Third, the amount of charcoal in the soil increased with increasing distance from the lake. The lake sediment core, which had a depth of 3 m and an age of 11 000 years, recorded a continuous influx of macroscopic charcoal throughout the Holocene. Interestingly, the amount of charcoal in the lake sediment exceeded that in the majority of the forest soil cores, indicating a relatively high degradation rate of charcoal in the forest soil and that charcoal is well preserved in the lake sediment.

  13. Impact of activated carbon, biochar and compost on the desorption and mineralization of phenanthrene in soil.

    PubMed

    Marchal, Geoffrey; Smith, Kilian E C; Rein, Arno; Winding, Anne; Wollensen de Jonge, Lis; Trapp, Stefan; Karlson, Ulrich G

    2013-10-01

    Sorption of PAHs to carbonaceous soil amendments reduces their dissolved concentrations, limiting toxicity but also potentially biodegradation. Therefore, the maximum abiotic desorption of freshly sorbed phenanthrene (≤5 mg kg(-1)) was measured in three soils amended with activated carbon (AC), biochar or compost. Total amounts of phenanthrene desorbed were similar between the different soils, but the amendment type had a large influence. Complete desorption was observed in the unamended and compost amended soils, but this reduced for biochar (41% desorbed) and AC (8% desorbed). Cumulative amounts mineralized were 28% for the unamended control, 19% for compost, 13% for biochar and 4% for AC. Therefore, the effects of the amendments in soil in reducing desorption were also reflected in the extents of mineralization. Modeling was used to analyze key processes, indicating that for the AC and charcoal treatments bacterial activity did not limit mineralization, but rather desorption into the dissolved phase.

  14. Technique for surface oxidation of activated carbon

    SciTech Connect

    Sircar, S.; Golden, T.C.

    1987-10-27

    A method of activating a carbon adsorbent is described, which comprises oxidizing the surface of the carbon adsorbent with a mild oxidizing acid in the presence of a metal oxidation catalyst at an elevated temperature and boiling the mixture of the carbon adsorbent, mild oxidizing acid and metal oxidation catalyst to dryness. Then rinse the surface oxidizing carbon adsorbent with water; and dry the rinsed surface oxidized carbon adsorbent. In a process for the removal of water or carbon dioxide from a gas stream containing water or carbon dioxide of the type wherein the gas stream containing water or carbon dioxide is contacted with a solid phase adsorbent under pressure-swing adsorption or thermal-swing adsorption processing conditions, the improvement is described comprising utilizing an adsorbent produced by the activation of a carbon adsorbent. The activation comprises oxidizing the surface of the carbon adsorbent with a mold oxidizing acid in the presence of a metal oxidation catalyst at an elevated temperature and boiling the mixture of the carbon adsorbent, mild oxidizing acid and metal oxidation catalyst to dryness. Then rinse the surface oxidized carbon adsorbent with water; and dry the rinsed surface oxidized carbon adsorbent.

  15. Adsorption of carbon monoxide on activated carbon tin ligand

    NASA Astrophysics Data System (ADS)

    Mohamad, A. B.; Iyuke, S. E.; Daud, W. R. W.; Kadhum, A. A. H.; Fisal, Z.; Al-Khatib, M. F.; Shariff, A. M.

    2000-09-01

    Activated carbon was impregnated with 34.57% SnCl 2·2H 2O salt and then dried at 180°C to produce AC-SnO 2 to improve its adsorptive interaction with CO. Besides the fact that activated carbon has its original different pore sizes for normal gas phase CO adsorption (as in the case of pure carbon), the impregnated carbon has additional CO adsorption ability due to the presence of O -(ads) on the active sites. AC-SnO 2 proved to be a superior adsorber of CO than pure carbon when used for H 2 purification in a PSA system. Discernibly, the high adsorptive selectivity of AC-SnO 2 towards gas phase CO portrays a good future for the applicability of this noble adsorbent, since CO has become a notorious threat to the global ecosystem due to the current level of air pollution.

  16. Carbonized material adsorbents for the removal of mercury from aqueous solutions

    SciTech Connect

    1996-10-01

    Charcoal in itself is porous making it an excellent material for activated charcoal manufacture. However, few studies have been conducted in harnessing its potential for adsorption purposes, especially in water treatment. This paper describes the possibility of utilizing charcoal materials from Sugi (Cryptomeria japonica) for adsorbing heavy metals like mercury from aqueous solutions of different concentrations. The effect of soaking time, pore analyses and chemical properties on the adsorption capabilities of the carbonized materials were discussed. The pH value and chemical oxygen demand (COD) monitored during the soaking period were also described.

  17. Characterization and Properties of Activated Carbon Prepared from Tamarind Seeds by KOH Activation for Fe(III) Adsorption from Aqueous Solution

    PubMed Central

    Mopoung, Sumrit; Moonsri, Phansiri; Palas, Wanwimon; Khumpai, Sataporn

    2015-01-01

    This research studies the characterization of activated carbon from tamarind seed with KOH activation. The effects of 0.5 : 1–1.5 : 1 KOH : tamarind seed charcoal ratios and 500–700°C activation temperatures were studied. FTIR, SEM-EDS, XRD, and BET were used to characterize tamarind seed and the activated carbon prepared from them. Proximate analysis, percent yield, iodine number, methylene blue number, and preliminary test of Fe(III) adsorption were also studied. Fe(III) adsorption was carried out by 30 mL column with 5–20 ppm Fe(III) initial concentrations. The percent yield of activated carbon prepared from tamarind seed with KOH activation decreased with increasing activation temperature and impregnation ratios, which were in the range from 54.09 to 82.03 wt%. The surface functional groups of activated carbon are O–H, C=O, C–O, –CO3, C–H, and Si–H. The XRD result showed high crystallinity coming from a potassium compound in the activated carbon. The main elements found in the activated carbon by EDS are C, O, Si, and K. The results of iodine and methylene blue adsorption indicate that the pore size of the activated carbon is mostly in the range of mesopore and macropore. The average BET pore size and BET surface area of activated carbon are 67.9764 Å and 2.7167 m2/g, respectively. Finally, the tamarind seed based activated carbon produced with 500°C activation temperature and 1.0 : 1 KOH : tamarind seed charcoal ratio was used for Fe(III) adsorption test. It was shown that Fe(III) was adsorbed in alkaline conditions and adsorption increased with increasing Fe(III) initial concentration from 5 to 20 ppm with capacity adsorption of 0.0069–0.019 mg/g. PMID:26689357

  18. [Study on influence between activated carbon property and immobilized biological activated carbon purification effect].

    PubMed

    Wang, Guang-zhi; Li, Wei-guang; He, Wen-jie; Han, Hong-da; Ding, Chi; Ma, Xiao-na; Qu, Yan-ming

    2006-10-01

    By means of immobilizing five kinds of activated carbon, we studied the influence between the chief activated carbon property items and immobilized bioactivated carbon (IBAC) purification effect with the correlation analysis. The result shows that the activated carbon property items which the correlation coefficient is up 0.7 include molasses, abrasion number, hardness, tannin, uniform coefficient, mean particle diameter and effective particle diameter; the activated carbon property items which the correlation coefficient is up 0.5 include pH, iodine, butane and tetrachloride. In succession, the partial correlation analysis shows that activated carbon property items mostly influencing on IBAC purification effect include molasses, hardness, abrasion number, uniform coefficient, mean particle diameter and effective particle diameter. The causation of these property items bringing influence on IBAC purification is that the activated carbon holes distribution (representative activated carbon property item is molasses) provides inhabitable location and adjust food for the dominance bacteria; the mechanical resist-crash property of activated carbon (representative activated carbon property items: abrasion number and hardness) have influence on the stability of biofilm; and the particle diameter size and distribution of activated carbon (representative activated carbon property items: uniform coefficient, mean particle diameter and effective particle diameter) can directly affect the force of water in IBAC filter bed, which brings influence on the dominance bacteria immobilizing on activated carbon.

  19. Charcoal/Nitrogen Adsorption Cryocooler

    NASA Technical Reports Server (NTRS)

    Bard, Steven

    1987-01-01

    Refrigerator with no wear-related moving parts produces 0.5 W of cooling at 118 K. When fully developed, refrigerator needs no electrical power, and life expectancy of more than 10 yr, operates unattended to cool sensitive infrared detectors for long periods. Only moving parts in adsorption cryocooler are check valves. As charcoal is cooled in canister, gas pressure drops, allowing inlet check valve to open and admit more nitrogen. When canister is heated, pressure rises, closing inlet valve and eventually opening outlet valve.

  20. Combustion efficiency and hydrocarbon emissions from charcoal production kilns in the tropics

    SciTech Connect

    Ward, D.E.; Hao, W.M.; Babbitt, R.E.

    1995-12-01

    Charcoal is one of the major energy resources in tropical countries. We investigate the combustion processes in charcoal production kilns in Zambia and Brazil. The Zambian kilns were made of earth and there was sufficient air for combustion inside the kilns. The Brazilian kilns were made of bricks which limited the available oxygen. The combustion efficiency and the concentrations of CO{sub 2}, CO, CH{sub 4}, C{sub 2}-C{sub 6} alkanes and alkenes, and aromatic compounds produced were monitored throughout the combustion processes. The contributions of charcoal production processes to the atmospheric sources of these gases were estimated. The strategies for improving charcoal yield and reducing emissions of carbon-containing compounds are discussed.

  1. CHARCOAL-PRODUCING INDUSTRIES IN NORTHEASTERN BRAZIL

    EPA Science Inventory

    Charcoal workers in northeastern Brazil: Occupational risks and effects of exposure to wood smoke
    ABSTRACT
    Brazil has the largest production of charcoal in the world, which is used mostly in the iron and steel industries. In most of the production sites, the process is ba...

  2. Development of charcoal sorbents for helium cryopumping

    SciTech Connect

    Sedgley, D.W.; Tobin, A.G.

    1985-09-30

    Improved methods for cryopumping helium were developed for application to fusion reactors where high helium generation rates are expected. This study period evaluated charcoal particle size, bonding agent type and thickness, and substrate thickness. The optimum combination of charcoal, bond, and substrate was used to form a scaled-up panel for evaluation in the Tritium Systems Test Assembly (TSTA) at Los Alamos. The optimum combination is a 12 x 30 mesh coconut charcoal attached to a 0.48 cm thick copper substrate by a 0.015 cm thick silver phosphorus copper braze. A copper cement bond for attaching charcoal to a substrate was identified and tested. Helium pumping performance of this combination was comparable to that of the charcoal braze system. Environmental tests showed the charcoal's susceptibility to vacuum chamber contamination. Performance degradation followed exposure of ambient temperature charcoal to a vacuum for prolonged periods. Maintaining a liquid nitrogen-cooled shield between the charcoal and the source of contamination prevented this degradation. A combination of bake-out and LN shielding effected recovery of degraded performance.

  3. Charcoal-methanol adsorption refrigerator powered by a compound parabolic concentrating solar collector

    SciTech Connect

    Headley, O.StC.; Kothdiwala, A.F.; McDoom, I.A. )

    1994-08-01

    A compound parabolic concentrating solar collector (CPC) of concentration ratio 3.9 and aperture area 2.0 m[sup 2] was used to power an intermittent solid adsorption refrigerator and ice maker using activated charcoal (carbon) as the adsorbing medium and methanol as the working fluid. The copper tube receiver of the CPC was packed with 2.5 kg of imported adsorbent 207E3, which was only utilized when the performance of activated charcoal (ACJ1, produced from local coconut shells) was found to be inferior to the imported adsorbent. Up to 1 kg of ice at an evaporator temperature of [minus]6[degrees]C was produced, with the net solar coefficient of performance (COP) being of the order of 0.02. Maximum receiver/adsorbent temperature recorded was 154[degrees]C on a day when the insolation was 26.8 MJ/m[sup [minus]2]. Temperatures in excess of 150[degrees]C are undesirable since they favour the conversion of methanol to dimethyl ether, a noncondensable gas which inhibits both condensation and adsorption. The major advantage of this system is its ability to produce ice even on overcast days (insolation [approximately] 10 MJ/m[sup [minus]2]).

  4. Spatiotemporal patterns of tundra fires: late-Quaternary charcoal records from Alaska

    NASA Astrophysics Data System (ADS)

    Chipman, M. L.; Hudspith, V.; Higuera, P. E.; Duffy, P. A.; Kelly, R.; Oswald, W. W.; Hu, F. S.

    2015-07-01

    Anthropogenic climate change has altered many ecosystem processes in the Arctic tundra and may have resulted in unprecedented fire activity. Evaluating the significance of recent fires requires knowledge from the paleofire record because observational data in the Arctic span only several decades, much shorter than the natural fire rotation in Arctic tundra regions. Here we report results of charcoal analysis on lake sediments from four Alaskan lakes to infer the broad spatial and temporal patterns of tundra-fire occurrence over the past 35 000 years. Background charcoal accumulation rates are low in all records (range is 0-0.05 pieces cm-2 yr-1), suggesting minimal biomass burning across our study areas. Charcoal peak analysis reveals that the mean fire-return interval (FRI; years between consecutive fire events) ranged from ca. 1650 to 6050 years at our sites, and that the most recent fire events occurred from ca. 880 to 7030 years ago, except for the CE 2007 Anaktuvuk River Fire. These mean FRI estimates are longer than the fire rotation periods estimated for the past 63 years in the areas surrounding three of the four study lakes. This result suggests that the frequency of tundra burning was higher over the recent past compared to the late Quaternary in some tundra regions. However, the ranges of FRI estimates from our paleofire records overlap with the expected values based on fire-rotation-period estimates from the observational fire data, and the differences are statistically insignificant. Together with previous tundra-fire reconstructions, these data suggest that the rate of tundra burning was spatially variable and that fires were extremely rare in our study areas throughout the late Quaternary. Given the rarity of tundra burning over multiple millennia in our study areas and the pronounced effects of fire on tundra ecosystem processes such as carbon cycling, dramatic tundra ecosystem changes are expected if anthropogenic climate change leads to more

  5. Spatiotemporal patterns of tundra fires: late-Quaternary charcoal records from Alaska

    NASA Astrophysics Data System (ADS)

    Chipman, M. L.; Hudspith, V.; Higuera, P. E.; Duffy, P. A.; Kelly, R.; Oswald, W. W.; Hu, F. S.

    2015-02-01

    Anthropogenic climate change has altered many ecosystem processes in the Arctic tundra and may have resulted in unprecedented fire activity. Evaluating the significance of recent fires requires knowledge from the paleo-fire record because observational data in the Arctic span only several decades, much shorter than the natural fire rotation in Arctic tundra regions. Here we report results of charcoal analysis on lake sediments from four Alaskan lakes to infer the broad spatial and temporal patterns of tundra fire occurrence over the past 35 000 years. Background charcoal accumulation rates are low in all records (range = 0-0.05 pieces cm-2 year-1), suggesting minimal biomass burning across our study areas. Charcoal peak analysis reveals that the mean fire return interval (FRI; years between consecutive fire events) ranged from 1648 to 6045 years at our sites, and that the most recent fire events occurred from 882 to 7031 years ago, except for the CE 2007 Anaktuvuk River Fire. These mean FRI estimates are longer than the fire rotation periods estimated for the past 63 years in the areas surrounding three of the four study lakes. This result suggests that the frequency of tundra burning was higher over the recent past compared to the late Quaternary in some tundra regions. However, the ranges of FRI estimates from our paleo-fire records overlap with the expected values based on fire-rotation-period estimates from the observational fire data, and thus quantitative differences are not significant. Together with previous tundra-fire reconstructions, these data suggest that the rate of tundra burning was spatially variable and that fires were extremely rare in our study areas throughout the late Quaternary. Given the rarity of tundra burning over multiple millennia in our study areas and the pronounced effects of fire on tundra ecosystem processes such as carbon cycling, dramatic tundra ecosystem changes are expected if anthropogenic climate change leads to more frequent

  6. Sorption of boron trifluoride by activated carbons

    SciTech Connect

    Polevoi, A.S.; Petrenko, A.E.

    1988-01-10

    The sorption of born trifluoride on AG-3, SKT, SKT-3, SKT-7, SKT-4A, SKT-6A, and SKT-2B carbons was investigated. The sorption isotherms for both vapors and gas were determined volumetrically. The coefficients of two equations described the sorption of BF/sub 3/ in the sorption of BF/sub 3/ on active carbons. Heats of sorption of BF/sub 3/ on the activated carbons are shown and the sorption isotherms and temperature dependences of the equilibrium pressure of BF/sub 3/ for activated carbons were presented. The values of the heats of sorption indicated the weak character of the reaction of BF/sub 3/ with the surface of the carbons. The equations can be used for calculating the phase equilibrium of BF/sub 3/ on carbons in a wider range of temperatures and pressures.

  7. Catalytic Growth of Macroscopic Carbon Nanofibers Bodies with Activated Carbon

    SciTech Connect

    Abdullah, N.; Muhammad, I. S.; Hamid, S. B. Abd.; Rinaldi, A.; Su, D. S.; Schlogl, R.

    2009-06-01

    Carbon-carbon composite of activated carbon and carbon nanofibers have been synthesized by growing Carbon nanofiber (CNF) on Palm shell-based Activated carbon (AC) with Ni catalyst. The composites are in an agglomerated shape due to the entanglement of the defective CNF between the AC particles forming a macroscopic body. The macroscopic size will allow the composite to be used as a stabile catalyst support and liquid adsorbent. The preparation of CNT/AC nanocarbon was initiated by pre-treating the activated carbon with nitric acid, followed by impregnation of 1 wt% loading of nickel (II) nitrate solutions in acetone. The catalyst precursor was calcined and reduced at 300 deg. C for an hour in each step. The catalytic growth of nanocarbon in C{sub 2}H{sub 4}/H{sub 2} was carried out at temperature of 550 deg. C for 2 hrs with different rotating angle in the fluidization system. SEM and N{sub 2} isotherms show the level of agglomeration which is a function of growth density and fluidization of the system. The effect of fluidization by rotating the reactor during growth with different speed give a significant impact on the agglomeration of the final CNF/AC composite and thus the amount of CNFs produced. The macrostructure body produced in this work of CNF/AC composite will have advantages in the adsorbent and catalyst support application, due to the mechanical and chemical properties of the material.

  8. Catalytic activation of carbon-carbon bonds in cyclopentanones.

    PubMed

    Xia, Ying; Lu, Gang; Liu, Peng; Dong, Guangbin

    2016-11-24

    In the chemical industry, molecules of interest are based primarily on carbon skeletons. When synthesizing such molecules, the activation of carbon-carbon single bonds (C-C bonds) in simple substrates is strategically important: it offers a way of disconnecting such inert bonds, forming more active linkages (for example, between carbon and a transition metal) and eventually producing more versatile scaffolds. The challenge in achieving such activation is the kinetic inertness of C-C bonds and the relative weakness of newly formed carbon-metal bonds. The most common tactic starts with a three- or four-membered carbon-ring system, in which strain release provides a crucial thermodynamic driving force. However, broadly useful methods that are based on catalytic activation of unstrained C-C bonds have proven elusive, because the cleavage process is much less energetically favourable. Here we report a general approach to the catalytic activation of C-C bonds in simple cyclopentanones and some cyclohexanones. The key to our success is the combination of a rhodium pre-catalyst, an N-heterocyclic carbene ligand and an amino-pyridine co-catalyst. When an aryl group is present in the C3 position of cyclopentanone, the less strained C-C bond can be activated; this is followed by activation of a carbon-hydrogen bond in the aryl group, leading to efficient synthesis of functionalized α-tetralones-a common structural motif and versatile building block in organic synthesis. Furthermore, this method can substantially enhance the efficiency of the enantioselective synthesis of some natural products of terpenoids. Density functional theory calculations reveal a mechanism involving an intriguing rhodium-bridged bicyclic intermediate.

  9. Making Activated Carbon by Wet Pressurized Pyrolysis

    NASA Technical Reports Server (NTRS)

    Fisher, John W.; Pisharody, Suresh; Wignarajah, K.; Moran, Mark

    2006-01-01

    A wet pressurized pyrolysis (wet carbonization) process has been invented as a means of producing activated carbon from a wide variety of inedible biomass consisting principally of plant wastes. The principal intended use of this activated carbon is room-temperature adsorption of pollutant gases from cooled incinerator exhaust streams. Activated carbon is highly porous and has a large surface area. The surface area depends strongly on the raw material and the production process. Coconut shells and bituminous coal are the primary raw materials that, until now, were converted into activated carbon of commercially acceptable quality by use of traditional production processes that involve activation by use of steam or carbon dioxide. In the wet pressurized pyrolysis process, the plant material is subjected to high pressure and temperature in an aqueous medium in the absence of oxygen for a specified amount of time to break carbon-oxygen bonds in the organic material and modify the structure of the material to obtain large surface area. Plant materials that have been used in demonstrations of the process include inedible parts of wheat, rice, potato, soybean, and tomato plants. The raw plant material is ground and mixed with a specified proportion of water. The mixture is placed in a stirred autoclave, wherein it is pyrolized at a temperature between 450 and 590 F (approximately between 230 and 310 C) and a pressure between 1 and 1.4 kpsi (approximately between 7 and 10 MPa) for a time between 5 minutes and 1 hour. The solid fraction remaining after wet carbonization is dried, then activated at a temperature of 500 F (260 C) in nitrogen gas. The activated carbon thus produced is comparable to commercial activated carbon. It can be used to adsorb oxides of sulfur, oxides of nitrogen, and trace amounts of hydrocarbons, any or all of which can be present in flue gas. Alternatively, the dried solid fraction can be used, even without the activation treatment, to absorb

  10. Ion-Selective Deposition of Manganese Sulphate Solution from Trenggalek Manganese Ore by Active Carbon and Sodium Hydroxide

    NASA Astrophysics Data System (ADS)

    Andriyah, L.; Sulistiyono, E.

    2017-02-01

    One of the step in manganese dioxide manufacturing process for battery industry is a purification process of lithium manganese sulphate solution. The elimination of impurities such as iron removal is important in hydrometallurgical processes. Therefore, this paper present the purification results of manganese sulphate solution by removing impurities using a selective deposition method, namely activated carbon adsorption and NaOH. The experimental results showed that the optimum condition of adsorption process occurs on the addition of 5 g adsorbent and the addition of 10 ml NaOH 1 N, processing time of 30 minutes and the best is the activated carbon adsorption of Japan. Because the absolute requirement of the cathode material of lithium ion manganese are free of titanium then of local wood charcoal is good enough in terms of eliminating ions Ti is equal to 70.88%.

  11. The influence of production conditions, starting material and deposition environment on charcoal alteration in a tropical biome.

    NASA Astrophysics Data System (ADS)

    Ascough, Philippa; Bird, Michael; Meredith, Will; Large, David; Snape, Colin; Manion, Corinne

    2014-05-01

    Natural and anthropogenic burning events are a key link in the global carbon cycle, substantially influencing atmospheric CO2 levels, and consuming c.8700 teragrams yr-1 of dry biomass [1,2,3]. An important result of this process is charcoal, when lignocellulosic structures in biomass (e.g. wood) are converted to aromatic domains with high chemical stability. Charcoal is therefore not readily re-oxidized to CO2, with estimates of 5-7 ky for the half-life of charcoal carbon in soils [3,4]. Charcoal's high carbon content coupled with high environmental resistance has led to the concept of biochar as a valuable means of global carbon sequestration, capable of carbon offsets comparable to annual anthropogenic fuel emissions [5,6,7]. Charcoal is not, however, an environmentally inert substance, and at least some components of charcoal are susceptible to alteration in depositional environments. Despite the importance of charcoal in global carbon cycling, the mechanisms by which charcoal is altered in the environment remain, as yet, poorly understood. This fact limits our ability to properly incorporate both natural environmental charcoal and biochar into global carbon budgets. This study aimed to improve understanding of charcoal alteration in the environment by examining the influence of production conditions, starting material and deposition environment on the physical and chemical characteristics of charcoal at a field site in the Daintree rainforest. These factors have been identified as critical in determining the dynamics of charcoal in depositional environments [8,9] and climatic conditions at the field site (in Tropical Queensland, Australia) are likely to result in extensive alteration of charcoal. Charcoal from wood (Nothofagus spp.), algae (Enteromorpha spp.), and sugarcane (Saccharum spp.) biomass was produced at temperatures over 300-500°C and exposed to conditions of varying pH and vegetation cover. The effect of these variables on charcoal chemistry

  12. Performance of Charcoal Cookstoves for Haiti, Part 2: Results from the Controlled Cooking Test

    SciTech Connect

    Lask, Kathleen; Jones, Jennifer; Booker, Kayje; Ceballos, Cristina; Yang, Nina; Gadgil, Ashok

    2011-11-30

    Five charcoal cookstoves were tested using a Controlled Cooking Test (CCT) developed from cooking practices in Haiti. Cookstoves were tested for total burn time, specific fuel consumption, and emissions of carbon monoxide (CO), carbon dioxide (CO2), and the ratio of carbon monoxide to carbon dioxide (CO/CO2). These results are presented in this report along with LBNL testers’ observations regarding the usability of the stoves.

  13. What can we tell from particle morphology in Mesozoic charcoal assemblages?

    NASA Astrophysics Data System (ADS)

    Crawford, Alastair; Belcher, Claire

    2015-04-01

    Sedimentary charcoal particles provide a valuable record of palaeofire activity on both human and geological timescales. Charcoal is both an unambiguous indicator of wildfire, and a means of preservation of plant material in an inert form; thus it records not only the occurrence and extent of wildfire, but also the species affected. While scanning electron microscopy can be usefully employed for precise taxonomic identification of charcoals, the time and cost associated with this limit the extent to which the technique is employed. Morphometric analysis of mesocharcoal particles (c. 125-1000 µm) potentially provides a simple method for obtaining useful information from optical microscopy images. Grass fires have been shown to produce mesocharcoal particles with a higher length-to-width ratio than woodland fuel sources. In Holocene archives, aspect ratio measurements are thus used to infer the broad taxonomic affinity of the burned vegetation. Since Mesozoic charcoals display similarly heterogeneous morphologies, we investigate whether there is a similar potential to infer the broad botanical affinities of Mesozoic charcoal assemblages from simple morphological metrics. We have used image analysis to analyse a range of Jurassic and Cretaceous sedimentary rocks representing different vegetation communities and depositional environments, and also to determine the range of charcoal particle morphologies which can be produced from different modern taxa under laboratory conditions. We find that modern charcoals break down into mesocharcoal particles of very variable aspect ratio, and this appears to be dependent on taxonomic position. Our analysis of fragmented laboratory-produced charcoals indicates that pteridophytes produce much more elongate particles than either conifers or non-grass angiosperms. We suggest that for charcoal assemblages that predate the evolution of grasses, high average aspect ratios may be a useful indicator of the burning of a pteridophyte

  14. Chemical and Isotopic Thresholds in Charring: Implications for the Interpretation of Charcoal Mass and Isotopic Data.

    PubMed

    Pyle, Lacey A; Hockaday, William C; Boutton, Thomas; Zygourakis, Kyriacos; Kinney, Timothy J; Masiello, Caroline A

    2015-12-15

    Charcoal plays a significant role in the long-term carbon cycle, and its use as a soil amendment is promoted as a C sequestration strategy (biochar). One challenge in this research area is understanding the heterogeneity of charcoal properties. Although the maximum reaction temperature is often used as a gauge of pyrolysis conditions, pyrolysis duration also changes charcoal physicochemical qualities. Here, we introduce a formal definition of charring intensity (CI) to more accurately characterize pyrolysis, and we document variation in charcoal chemical properties with variation in CI. We find two types of responses to CI: either linear or threshold relationships. Mass yield decreases linearly with CI, while a threshold exists across which % C, % N, and δ(15)N exhibit large changes. This CI threshold co-occurs with an increase in charcoal aromaticity. C isotopes do not change from original biomass values, supporting the use of charcoal δ(13)C signatures to infer paleoecological conditions. Fractionation of N isotopes indicates that fire may be enriching soils in (15)N through pyrolytic N isotope fractionation. This influx of "black N" could have a significant impact on soil N isotopes, which we show theoretically using a simple mass-balance model.

  15. The transport properties of activated carbon fibers

    SciTech Connect

    di Vittorio, S.L. . Dept. of Materials Science and Engineering); Dresselhaus, M.S. . Dept. of Electrical Engineering and Computer Science Massachusetts Inst. of Tech., Cambridge, MA . Dept. of Physics); Endo, M. . Dept. of Electrical Engineering); Issi, J-P.; Piraux, L.

    1990-07-01

    The transport properties of activated isotropic pitch-based carbon fibers with surface area 1000 m{sup 2}/g have been investigated. We report preliminary results on the electrical conductivity, the magnetoresistance, the thermal conductivity and the thermopower of these fibers as a function of temperature. Comparisons are made to transport properties of other disordered carbons. 19 refs., 4 figs.

  16. Solvent recovery improved with activated carbon fibers

    SciTech Connect

    Not Available

    1982-11-01

    A non-woven net of activated carbon fibers as absorbing media, representing a major advancement in vapor recovery technology, is presented. The carbon fiber exhibits mass transfer coefficients for adsorption description of up to 100 times that of conventional systems.

  17. The Transport Properties of Activated Carbon Fibers

    DOE R&D Accomplishments Database

    di Vittorio, S. L.; Dresselhaus, M. S.; Endo, M.; Issi, J-P.; Piraux, L.

    1990-07-01

    The transport properties of activated isotropic pitch-based carbon fibers with surface area 1000 m{sup 2}/g have been investigated. We report preliminary results on the electrical conductivity, the magnetoresistance, the thermal conductivity and the thermopower of these fibers as a function of temperature. Comparisons are made to transport properties of other disordered carbons.

  18. Chemical activation of carbon mesophase pitches.

    PubMed

    Mora, E; Blanco, C; Pajares, J A; Santamaría, R; Menéndez, R

    2006-06-01

    This paper studies the chemical activation of mesophase pitches of different origins in order to obtain activated carbons suitable for use as electrodes in supercapacitors. The effect that the activating agent (NaOH, LiOH, and KOH), the alkaline hydroxide/pitch ratio, and the activation temperature had on the characteristics of the resultant activated carbons was studied. LiOH was found to be a noneffective activating agent, while activation with NaOH and KOH yielded activated carbons with high apparent surface areas and pore volumes. The increase of the KOH/pitch ratio caused an increase of the chemical attack on the carbon, producing higher burnoffs and development of porosity. Extremely high apparent surface areas were obtained when the petroleum pitch was activated with 5:1 KOH/carbon ratio. The increase of the activation temperature caused an increase of the burnoff, although the differences were not as significant as those derived from the use of different proportions of activating agent.

  19. ACTIVATED CARBON FROM LIGNITE FOR WATER TREATMENT

    SciTech Connect

    Edwin S. Olson; Daniel J. Stepan

    2000-07-01

    High concentrations of humate in surface water result in the formation of excess amounts of chlorinated byproducts during disinfection treatment. These precursors can be removed in water treatment prior to disinfection using powdered activated carbon. In the interest of developing a more cost-effective method for removal of humates in surface water, a comparison of the activities of carbons prepared from North Dakota lignites with those of commercial carbons was conducted. Previous studies indicated that a commercial carbon prepared from Texas lignite (Darco HDB) was superior to those prepared from bituminous coals for water treatment. That the high alkali content of North Dakota lignites would result in favorable adsorptive properties for the very large humate molecules was hypothesized, owing to the formation of larger pores during activation. Since no standard humate test has been previously developed, initial adsorption testing was performed using smaller dye molecules with various types of ionic character. With the cationic dye, methylene blue, a carbon prepared from a high-sodium lignite (HSKRC) adsorbed more dye than the Darco HDB. The carbon from the low-sodium lignite was much inferior. With another cationic dye, malachite green, the Darco HDB was slightly better. With anionic dyes, methyl red and azocarmine-B, the results for the HSKRC and Darco HDB were comparable. A humate test was developed using Aldrich humic acid. The HSKRC and the Darco HDB gave equally high adsorption capacities for the humate (138 mg/g), consistent with the similarities observed in earlier tests. A carbon prepared from a high-sodium lignite from a different mine showed an outstanding improvement (201 mg/g). The carbons prepared from the low-sodium lignites from both mines showed poor adsorption capacities for humate. Adsorption isotherms were performed for the set of activated carbons in the humate system. These exhibited a complex behavior interpreted as resulting from two types

  20. 49 CFR 176.405 - Stowage of charcoal.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Stowage of charcoal. 176.405 Section 176.405... Materials § 176.405 Stowage of charcoal. (a) Before stowing charcoal Division 4.2 (flammable solid), UN 1361... petroleum product, a vegetable or animal oil, nitrate, or sulfur, must be removed. (b) Charcoal packed...

  1. 49 CFR 176.405 - Stowage of charcoal.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Stowage of charcoal. 176.405 Section 176.405... Materials § 176.405 Stowage of charcoal. (a) Before stowing charcoal Division 4.2 (flammable solid), UN 1361... petroleum product, a vegetable or animal oil, nitrate, or sulfur, must be removed. (b) Charcoal packed...

  2. 49 CFR 176.405 - Stowage of charcoal.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Stowage of charcoal. 176.405 Section 176.405... Materials § 176.405 Stowage of charcoal. (a) Before stowing charcoal Division 4.2 (flammable solid), UN 1361... petroleum product, a vegetable or animal oil, nitrate, or sulfur, must be removed. (b) Charcoal packed...

  3. 49 CFR 176.405 - Stowage of charcoal.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Stowage of charcoal. 176.405 Section 176.405... Materials § 176.405 Stowage of charcoal. (a) Before stowing charcoal Division 4.2 (flammable solid), UN 1361... petroleum product, a vegetable or animal oil, nitrate, or sulfur, must be removed. (b) Charcoal packed...

  4. 49 CFR 176.405 - Stowage of charcoal.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Stowage of charcoal. 176.405 Section 176.405... Materials § 176.405 Stowage of charcoal. (a) Before stowing charcoal Division 4.2 (flammable solid), UN 1361... petroleum product, a vegetable or animal oil, nitrate, or sulfur, must be removed. (b) Charcoal packed...

  5. Pyrolytic and oxidative syntheses of high-yield carbons from biomass

    NASA Astrophysics Data System (ADS)

    Dai, Xiangfeng

    A pressurized chemical reactor was designed and built per ASME code, which is capable of conducting pyrolysis, activation and gasification processes with an available volume of 7.2 L. It can operate at a pressure up to 3.5 MPa and the system provides a maximum saturated steam flow rate of 2.4 kg/hr at 5.4 MPa. With this reactor, the effects of moisture content, pressure and pretreatment of feedstock on synthesizing charcoal and its yields and properties were examined. Higher moisture content favors charcoal formation and leads to uniform properties of charcoal throughout the bed. However, it demands more external energy. Increase in operation pressure also favors higher yield of charcoal with reduced cook time, but not significantly for pressure above 1 MPa. Woods sorbed with CuSOsb4 and FeSOsb4 result in higher yield and/or better quality as well as short cook time. Charcoals from woods and nutshells have yields around 40% to 65% with a gross calorific value over 30 MJ/kg. A novel process for synthesizing high-yield activated carbon from Macshells was discovered, which involves air activation. Together with equations derived from energy balance, a model describing mass transport and reaction was developed for evaluating roles of diffusion in oxygenating biomass charcoal. Carbonization step is found necessary for subsequent oxygenation and activation in obtaining high-yield activated carbon. Both modeled and experimental results show no influence of mass transport in oxygenation at a temperature below 560 K, and good agreement in temperature rise due to reaction. Results from the kinetics model and the experiments indicate first-order reaction kinetics in oxygenation with respect to oxygen partial pressure. Evaluation on the values of increase in surface area (or iodine number) per carbon loss for activated carbon obtained by this process shows more effective use of carbon compared to the conventional method. Ultimate analyses show high carbon content and low ash

  6. Monitoring by Control Technique - Activated Carbon Adsorber

    EPA Pesticide Factsheets

    Stationary source emissions monitoring is required to demonstrate that a source is meeting the requirements in Federal or state rules. This page is about Activated Carbon Adsorber control techniques used to reduce pollutant emissions.

  7. Development of an incineration system for pulverized spent charcoal

    SciTech Connect

    Furukawa, Osamu; Shibata, Minoru; Kani, Koichi

    1995-12-31

    In the existing charcoal treatment system granular charcoal is charged directly into an incinerator together with other combustible waste. Since the combustion rate of the charcoal is slow in this system, there is a problem that unburnt charcoal accumulates at the bottom of the incinerator, when incineration is performed for an extended period of time. To prevent this difficulty, the combustion rate of the charcoal must be limited to 6 kg/h. To increase the incineration rate of charcoal, the authors have developed a system in which the charcoal is pulverized and incinerated while it is mixed with propane gas. The operational performance of this system was tested using an actual equipment.

  8. Soil charcoal to assess the impacts of past human disturbances on tropical forests.

    PubMed

    Vleminckx, Jason; Morin-Rivat, Julie; Biwolé, Achille B; Daïnou, Kasso; Gillet, Jean-François; Doucet, Jean-Louis; Drouet, Thomas; Hardy, Olivier J

    2014-01-01

    The canopy of many central African forests is dominated by light-demanding tree species that do not regenerate well under themselves. The prevalence of these species might result from ancient slash-and-burn agricultural activities that created large openings, while a decline of these activities since the colonial period could explain their deficit of regeneration. To verify this hypothesis, we compared soil charcoal abundance, used as a proxy for past slash-and-burn agriculture, and tree species composition assessed on 208 rainforest 0.2 ha plots located in three areas from Southern Cameroon. Species were classified in regeneration guilds (pioneer, non-pioneer light-demanding, shade-bearer) and characterized by their wood-specific gravity, assumed to reflect light requirement. We tested the correlation between soil charcoal abundance and: (i) the relative abundance of each guild, (ii) each species and family abundance and (iii) mean wood-specific gravity. Charcoal was found in 83% of the plots, indicating frequent past forest fires. Radiocarbon dating revealed two periods of fires: "recent" charcoal were on average 300 years old (up to 860 BP, n = 16) and occurred in the uppermost 20 cm soil layer, while "ancient" charcoal were on average 1900 years old (range: 1500 to 2800 BP, n = 43, excluding one sample dated 9400 BP), and found in all soil layers. While we expected a positive correlation between the relative abundance of light-demanding species and charcoal abundance in the upper soil layer, overall there was no evidence that the current heterogeneity in tree species composition can be explained by charcoal abundance in any soil layer. The absence of signal supporting our hypothesis might result from (i) a relatively uniform impact of past slash-and-burn activities, (ii) pedoturbation processes bringing ancient charcoal to the upper soil layer, blurring the signal of centuries-old Human disturbances, or (iii) the prevalence of other environmental

  9. COMPARISON OF SAMPLING METHODS FOR SEMI-VOLATILE ORGANIC CARBON ASSOCIATED WITH PM 2.5

    EPA Science Inventory

    This study evaluates the influence of denuder sampling methods and filter collection media on the measurement of semi-volatile organic carbon (SVOC) associated with PM2.5. Two types of collection media, charcoal (activated carbon) and XAD, were used both in diffusion denuders ...

  10. Removal of nitrate-nitrogen from drinking water using bamboo powder charcoal.

    PubMed

    Mizuta, Kei; Matsumoto, Toshitatsu; Hatate, Yasuo; Nishihara, Keiichi; Nakanishi, Tomoki

    2004-12-01

    The adsorption effectiveness of bamboo powder charcoal (BPC); made from the residual of Moso bamboo manufacturing; in removing nitrate-nitrogen from water has been investigated. Commercial activated carbon (CAC) was also used to compare the effectiveness of adsorption in removal of nitrate-nitrogen. The adsorption effectiveness of BPC was higher than that of CAC; regardless of the concentration of nitrate-nitrogen; in the range of 0-10 mg/l. The effect of temperature on adsorption by BPC and CAC in the range of 10-20 degrees C was also investigated. From the results, it was found that the temperature dependency of the adsorption effectiveness of BPC was weaker than that of CAC. This fact indicates that BPC can be an attractive option for the in situ treatment by adsorption of nitrate-nitrogen-contaminated underground and surface water.

  11. Interactive effects of biochar ageing in soils related to feedstock, pyrolysis temperature, and historic charcoal production.

    NASA Astrophysics Data System (ADS)

    Heitkötter, Julian; Marschner, Bernd

    2015-04-01

    Biochar is suggested for soil amelioration and carbon sequestration, based on its assumed role as the key factor for the long-term fertility of Terra preta soils. Several studies have shown that certain biochar properties can undergo changes through ageing processes, especially regarding charge characteristics. However, only a few studies determined the changes of different biochars under the same incubation conditions and in different soils. The objective of this study was to characterize the changes of pine chip (PC)- and corn digestate (CD)-derived biochars pyrolyzed at 400 or 600 °C during 100 days of laboratory incubation in a historical kiln soil and an adjacent control soil. Separation between soil and biochar was ensured by using mesh bags. Especially, changes in charge characteristics depended on initial biochar properties affected by feedstock and pyrolysis temperature and on soil properties affected by historic charcoal production. While the cation exchange capacity (CEC) markedly increased for both CD biochars during incubation, PC biochars showed no or only slight increases in CEC. Corresponding to the changes in CEC, ageing of biochars also increased the amount of acid functional groups with increases being in average about 2-fold higher in CD biochars than in PC biochars. Further and in contrast to other studies, the surface areas of biochars increased during ageing, likely due to ash leaching and degradation of tar residues. Changes in CEC and surface acidity of CD biochars were more pronounced after incubation in the control soil, while surface area increase was higher in the kiln soil. Since the two acidic forest soils used in this this study did not greatly differ in physical or chemical properties, the main process for inducing these differences in the buried biochar most likely is related to the differences in dissolved organic carbon (DOC). Although the kiln soil contained about 50% more soil organic carbon due to the presence of charcoal

  12. Mapping the Legacies of Historic Charcoal Production

    NASA Astrophysics Data System (ADS)

    Schneider, A.; Raab, A.; Raab, T. A.; Takla, M.; Nicolay, A.; Rösler, H.

    2014-12-01

    The historic production of charcoal is an important component of the late Holocene fire history for many landscapes. Charcoal production can have numerous effects on ecosystems, e.g., through changes in forest area and structure, or through the effects of pyrolysis, charcoal and ash addition to soils. To assess such effects, it is necessary to understand the spatial extent and patterns of historic charcoal production, which has so far hardly been approached for the Northern European Lowlands. In the forefield of the open-cast mine Jänschwalde (north of Cottbus, Germany), archaeological excavations have revealed one of the largest charcoal production fields described so far. For this area, we applied and evaluated different methods for mapping the spatial distribution of charcoal kiln remains. We present methods and results of our work in this exceptionally well-described charcoal production field and of additional studies on kiln site distribution in regions of the Northern European Lowlands. The large-scale excavations in the mine forefield provide exact information on kiln site geometry. Using airborne laser scanning elevation models, the mapping of kiln sites could be extended to areas beyond the mine forefield. To detect kiln sites for larger areas, an automated GIS based mapping routine, based on a combination of morphometric parameters, was developed and evaluated. By manual digitization from Shaded Relief Maps, more than 5000 kiln sites in an area of 32 km2 were detected in the Jänschwalde mine forefield, with 1355 kiln sites that are wider than 12 m. These relatively large kiln sites could be mapped with detection rates that are close to those of manual digitization using the automated routine. First results for different study areas indicate that charcoal production is a so far underestimated component of the land use history in many parts of the Northern European Lowlands.

  13. Charcoal Performance under Simulated Accident Conditions.

    DTIC Science & Technology

    1982-06-30

    demonstrated how TEDA impregnations alone will behave. 30 6. REFERENCES (1) "Effects of Weathering on Impregnated Charcoal Perform- ance," Victor R. Deitz, NUREG ...CR-2112, NRL Memo Report 4516 (1981). (2) "Effects of Weathering on Impregnated Charcoal Perform- ance," Victor R. Deitz, NRL Memo Report 4006, NUREG ...Characteristics. 4 i i 42 BIBLIOGRAPHIC DATA SHEET NUREG /CR/2550 9. PERFORMING ORGANIZATION NAME AND MAILING ADDRESS finclud ZIP Cod.) DATE REPORT ISSUED Naval

  14. Antimicrobial Activity of Carbon-Based Nanoparticles

    PubMed Central

    Maleki Dizaj, Solmaz; Mennati, Afsaneh; Jafari, Samira; Khezri, Khadejeh; Adibkia, Khosro

    2015-01-01

    Due to the vast and inappropriate use of the antibiotics, microorganisms have begun to develop resistance to the commonly used antimicrobial agents. So therefore, development of the new and effective antimicrobial agents seems to be necessary. According to some recent reports, carbon-based nanomaterials such as fullerenes, carbon nanotubes (CNTs) (especially single-walled carbon nanotubes (SWCNTs)) and graphene oxide (GO) nanoparticles show potent antimicrobial properties. In present review, we have briefly summarized the antimicrobial activity of carbon-based nanoparticles together with their mechanism of action. Reviewed literature show that the size of carbon nanoparticles plays an important role in the inactivation of the microorganisms. As major mechanism, direct contact of microorganisms with carbon nanostructures seriously affects their cellular membrane integrity, metabolic processes and morphology. The antimicrobial activity of carbon-based nanostructures may interestingly be investigated in the near future owing to their high surface/volume ratio, large inner volume and other unique chemical and physical properties. In addition, application of functionalized carbon nanomaterials as carriers for the ordinary antibiotics possibly will decrease the associated resistance, enhance their bioavailability and provide their targeted delivery. PMID:25789215

  15. Preparation of a new adsorbent from activated carbon and carbon nanofiber (AC/CNF) for manufacturing organic-vacbpour respirator cartridge

    PubMed Central

    2013-01-01

    In this study a composite of activated carbon and carbon nanofiber (AC/CNF) was prepared to improve the performance of activated carbon (AC) for adsorption of volatile organic compounds (VOCs) and its utilization for respirator cartridges. Activated carbon was impregnated with a nickel nitrate catalyst precursor and carbon nanofibers (CNF) were deposited directly on the AC surface using catalytic chemical vapor deposition. Deposited CNFs on catalyst particles in AC micropores, were activated by CO2 to recover the surface area and micropores. Surface and textural characterizations of the prepared composites were investigated using Brunauer, Emmett and Teller’s (BET) technique and electron microscopy respectively. Prepared composite adsorbent was tested for benzene, toluene and xylene (BTX) adsorption and then employed in an organic respirator cartridge in granular form. Adsorption studies were conducted by passing air samples through the adsorbents in a glass column at an adjustable flow rate. Finally, any adsorbed species not retained by the adsorbents in the column were trapped in a charcoal sorbent tube and analyzed by gas chromatography. CNFs with a very thin diameter of about 10-20 nm were formed uniformly on the AC/CNF. The breakthrough time for cartridges prepared with CO2 activated AC/CNF was 117 minutes which are significantly longer than for those cartridges prepared with walnut shell- based activated carbon with the same weight of adsorbents. This study showed that a granular form CO2 activated AC/CNF composite could be a very effective alternate adsorbent for respirator cartridges due to its larger adsorption capacities and lower weight. PMID:23369424

  16. Fluidized bed charcoal particle production system

    SciTech Connect

    Sowards, N.K.

    1985-04-09

    A fluidized bed charcoal particle production system, including apparatus and method, wherein pieces of combustible waste, such as sawdust, fragments of wood, etc., are continuously disposed within a fluidized bed of a pyrolytic vessel. Preferably, the fluidized bed is caused to reach operating temperatures by use of an external pre-heater. The fluidized bed is situated above an air delivery system at the bottom of the vessel, which supports pyrolysis within the fluidized bed. Charcoal particles are thus formed within the bed from the combustible waste and are lifted from the bed and placed in suspension above the bed by forced air passing upwardly through the bed. The suspended charcoal particles and the gaseous medium in which the particles are suspended are displaced from the vessel into a cyclone mechanism where the charcoal particles are separated. The separated charcoal particles are quenched with water to terminate all further charcoal oxidation. The remaining off-gas is burned and, preferably, the heat therefrom used to generate steam, kiln dry lumber, etc. Preferably, the bed material is continuously recirculated and purified by removing tramp material.

  17. A method for removing copper from charcoal of waste wood using an electrical current.

    PubMed

    Goto, S; Xiong, J F; Nakajima, D; Inaba, K; Ohata, M; Yoshizawa, S; Yajima, H; Sakai, S

    2007-08-01

    The reclamation of resources from wastes, through such activities as recycling various kinds of wastes and finding more ways to use them, is an important part of changing to a sustainable society. It is also important to ensure the safety of products by, for example, removing hazardous substances from recycled items. Wood is a type of demolition waste. The reuse and recycling of wood from demolition have not progressed much. To increase the number of ways of using wood wastes we have examined methods of making carbonized materials from them and using these carbonized materials to control indoor air pollution (Shibano et al., 2002). Research currently underway on ensuring the safety of recycled items includes investigating the behavior and other characteristics of hazardous substances that are, or may very well be, found in recycled items. It is known that the smoke arising from the process of carbonizing wood wastes is mutagenic. However, such mutagenic components become smoke and separate from carbonized materials, and, especially at temperatures of 800 degrees C and higher, they hardly remain in carbonized materials at all (Nakajima et al., 2003, 2004). In the carbonization of wood wastes containing hazardous metals such as CCA (Cr, Cu, As)-treated wood, substances that readily vaporize separate from the carbonized materials. One cannot expect, however, the same removal effect on metals that vaporize with difficulty, such as Cu, making it likely that they remain in the carbonized material (Takahashi et al., 2004). To examine methods of removing hazardous metals which may well remain in carbonized wood wastes, we investigated the removal and recovery of copper from charcoal with a high copper content by applying electricity (direct current) to it.

  18. Converting Poultry Litter into Activated Carbon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Disposal of animal manure is one of the biggest problems facing agriculture today. Now new technology has been designed to covert manure into environmentally friendly and highly valued activated carbon. When pelletized and activated under specific conditions, the litter becomes a highly porous mat...

  19. Deposition of Magnetite Nanoparticles in Activated Carbons and Preparation of Magnetic Activated Carbons

    NASA Astrophysics Data System (ADS)

    Kahani, S. A.; Hamadanian, M.; Vandadi, O.

    2007-08-01

    Magnetic activated carbons (MACs) for gold recovery from alkaline cyanide solutions have been developed by mixing a magnetic precursor with a carbon source, and treating the mixture under controlled conditions. As would be expected, these activated carbons have high specific surface areas due to their microporous structure. In addition, the small particle size of the MACs produced allows rapid adsorption of gold in solution, and the magnetic character of these MACs enables recovery from suspension by magnetic separation.

  20. Enhanced photocatalytic degradation and adsorption of methylene blue via TiO2 nanocrystals supported on graphene-like bamboo charcoal

    NASA Astrophysics Data System (ADS)

    Wu, Fangjun; Liu, Wei; Qiu, Jielong; Li, Jinzhen; Zhou, Wuyi; Fang, Yueping; Zhang, Shuting; Li, Xin

    2015-12-01

    In this study, a novel efficient photocatalytic nanomaterial, TiO2 nanocrystals supported on graphene-like bamboo charcoal, has been successfully synthesized via a facile multi-step process. The structural and optical properties of the as-prepared samples were characterized by different techniques, such as X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis absorption spectroscopy, photoluminescence spectra (PL), Raman spectra and nitrogen adsorption-desorption isotherms. The photocatalytic activities under sunlight were evaluated by the degradation of methylene blue (MB). The results indicated that the ternary hybrid photocatalysts exhibited much higher photocatalytic activities toward the degradation of MB than the pure TiO2 under UV light irradiation. Moreover, the optimum weight content of graphene-like bamboo charcoal in composite photocatalysts was 6 wt% for achieving the maximum photocatalytic degradation rate. The apparent rate constant of the best sample (0.0509 min-1) was about 3 times greater than that of the commercial P25 (0.0170 min-1). The adsorption and degradation kinetics of MB can be described by the pseudo-first-order model and apparent first-order kinetics model, respectively. The highly enhanced photocatalytic performance was attributed to the synergetic effect of graphene-like carbon and bamboo charcoal, which lead to the promoted charge separation and reduction reaction of oxygen, and enhanced adsorption capacities of MB, respectively. The composite photocatalysts displayed a high photochemical stability under repeated irradiation. This work may provide new insights and understanding on the graphene-like bamboo charcoal as an excellent support for photocatalyst nanoparticles to enhance their visible-light photocatalytic activity.

  1. New emission controls for Missouri batch-type charcoal kilns

    SciTech Connect

    Yronwode, P.; Graf, W.J.

    1999-07-01

    Charcoal kilns have been exempted from air emission regulation in the state of Missouri. Today, 80% of US charcoal production takes place in Missouri. As a result of a petition filed by people in the area around an installation in southern Missouri, the US Environmental Protection Agency (EPA) set up air monitors and measured ambient air levels at that charcoal manufacturing installation. These monitors yielded the highest particulate matter less than 10 micron (PM{sub 10}) levels ever recorded in the state. Earlier stack testing at another charcoal manufacturing installation indicated that toxics and carcinogens are present in charcoal kiln air emissions. A Charcoal Kiln Workgroup was formed to determine the Best Available Control Technology (BACT) for charcoal kilns and to draft a charcoal kiln rule that requires BACT. The BACT report determined that afterburners were suitable for controlling emissions from batch-type charcoal kilns. In addition, the charcoal industry supported incorporating the BACT limits and requirements into an enforceable state rule and submitting this rule to the EPA for federal approval. A consent agreement between the EPA and three major charcoal companies was signed with provisions to install, operate, and maintain emission control devices on charcoal kilns. This agreement was to settle complaints alleging that the three major charcoal producers had failed to report toxic air emissions to federal and state regulators. The agreement provided that industry would install control devices on a set schedule with some charcoal kilns being shut down.

  2. Post-Flight Sampling and Loading Characterization of Trace Contaminant Control Subassembly Charcoal

    NASA Technical Reports Server (NTRS)

    Perry, J. L.; Cole, H. E.; Cramblitt, E. L.; El-Lessy, H. N.; Manuel, S.; Tucker, C. D.

    2003-01-01

    Trace chemical contaminants produced by equipment offgassing and human metabolic processes are removed from the atmosphere of the International Space Station s U.S. Segment by a trace contaminant control subassembly (TCCS). The TCCS employs a combination of physical adsorption, thermal catalytic oxidation, and chemical adsorption processes to accomplish its task. A large bed of granular activated charcoal is a primary component of the TCCS. The charcoal contained in this bed, known as the charcoal bed assembly (CBA), is expendable and must be replaced periodically. Pre-flight engineering analyses based upon TCCS performance testing results established a service life estimate of 1 year. After nearly 1 year of cumulative in-flight operations, the first CBA was returned for refurbishment. Charcoal samples were collected and analyzed for loading to determine the best estimate for the CBAs service life. A history of in-flight TCCS operations is presented as well as a discussion of the charcoal sampling procedures and chemical analysis results. A projected service life derived from the observed charcoal loading is provided. Recommendations for better managing TCCS resources are presented.

  3. NMR-based estimates of the molecular dimensions in wildfire charcoal: Implications for predictions of biochar residence time

    NASA Astrophysics Data System (ADS)

    Hockaday, William; Kane, Evan; Huang, Rixiang; Von Bargen, Justin; Davis, Rebecca; Ohlson, Mikael

    2014-05-01

    The thermochemical conversion of biomass to energy and fuels generates charcoal as a co-product. Charcoals derived from sustainable biomass sources—biochars—are an inherently stable form of carbon, relatively long residence times in the environment. Biochars can have potentially beneficial properties as soil fertility amendments, which has further stimulated research on the use of biochars for soil carbon sequestration as a climate change mitigation strategy. However, it is challenging to assess the long-term stability of biochar carbon using laboratory or field incubations because these are comprised of short-term observations. In this study, we make use of ancient charcoals from the boreal forests of Alaska and Scandanavia. We have deliberately selected charcoals from organic soil horizons, as to investigate the inherent biological and chemical stability of charcoal C without the protective influence of soil minerals. We use 14C radiocarbon dating to determine the age of the charcoals, differential scanning calorimetry to assess thermal stability, and solid-state 13C NMR to assess the chemical structure. Specifically, we employ C-H dipolar-dephasing NMR experiments to estimate the relative abundance and molecular dimensions of condensed aromatic domains and aliphatic structures. We test the hypothesis that the environmental stability, as determined by apparent 14C age and thermal stability, is related to the extent of ring condensation in the charcoal structure. Preliminary results suggest that the dimension of the condensed aromatic ring clusters may be an important molecular parameter to include in algorithms used to model/predict the residence time of charcoal and biochar C in soil.

  4. A novel activated carbon for supercapacitors

    SciTech Connect

    Shen, Haijie; Liu, Enhui; Xiang, Xiaoxia; Huang, Zhengzheng; Tian, Yingying; Wu, Yuhu; Wu, Zhilian; Xie, Hui

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer A novel activated carbon was prepared from phenol-melamine-formaldehyde resin. Black-Right-Pointing-Pointer The carbon has large surface area with microporous, and high heteroatom content. Black-Right-Pointing-Pointer Heteroatom-containing functional groups can improve the pseudo-capacitance. Black-Right-Pointing-Pointer Physical and chemical properties lead to the good electrochemical properties. -- Abstract: A novel activated carbon has been prepared by simple carbonization and activation of phenol-melamine-formaldehyde resin which is synthesized by the condensation polymerization method. The morphology, thermal stability, surface area, elemental composition and surface chemical composition of samples have been investigated by scanning electron microscope, thermogravimetry and differential thermal analysis, Brunauer-Emmett-Teller measurement, elemental analysis and X-ray photoelectron spectroscopy, respectively. Electrochemical properties have been studied by cyclic voltammograms, galvanostatic charge/discharge, and electrochemical impedance spectroscopy measurements in 6 mol L{sup -1} potassium hydroxide. The activated carbon shows good capacitive behavior and the specific capacitance is up to 210 F g{sup -1}, which indicates that it may be a promising candidate for supercapacitors.

  5. COMPARISON OF SAMPLING METHODS FOR SEMI-VOLATILE ORGANIC CARBON (SVOC) ASSOCIATED WITH PM 2.5

    EPA Science Inventory

    This study evaluates the influence of denuder sampling methods and filter collection media on the measurement of semi-volatile organic carbon (SVOC) associated with PM2.5. Two types of collection media, charcoal (activated carbon) and XAD, were used both in diffusion denuders ...

  6. Comparison of sampling methods for semi-volatile organic carbonAssociated with PM2.5

    SciTech Connect

    Lewtas, Joellen; Booth, Derrick; Pang, Yanbo; Reimer, Steve; Eatough, Delbert J.; Gundel, Lara A.

    2001-06-29

    This study evaluates the influence of denuder sampling methods and filter collection media on the measurement of semi-volatile organic carbon (SVOC) associated with PM2.5. Two types of collection media, charcoal (activated carbon) and XAD, were used both in diffusion denuders and impregnated back-up filters in two different samplers, the VAPS and the PC-BOSS. The two organic diffusion denuders were XAD-coated glass annular denuders and charcoal-impregnated cellulose fiber filter(CIF) denuders. In addition, recently developed XAD-impregnated quartz filters were compared to CIF filters as back-up filter collection media. The two denuder types resulted in equivalent measurement of particulate organic carbon and particle mass. The major difference observed between the XAD and charcoal BOSS denuders is the higher efficiency of charcoal for collection of more volatile carbon. This more volatile carbon does not contribute substantially to the particle mass or SVOC measured as OC on quartz filters downstream of the denuders. This volatile carbon does result in high OC concentrations observed in charcoal filters placed behind quartz filters downstream of the XAD denuders and would result in overestimating the SVOC in that configuration.

  7. Degradation of organic matter from black shales and charcoal by the wood-rotting fungus Schizophyllum commune and release of DOC and heavy metals in the aqueous phase.

    PubMed

    Wengel, Marcus; Kothe, Erika; Schmidt, Christian M; Heide, Klaus; Gleixner, Gerd

    2006-08-15

    that the degradation of persistent carbon sources, such as charcoal and black shale, is accelerated by fungal activity. Consequently, the associated release of heavy metals is also accelerated by the fungus. Main products of the biological degradation processes were organic heavy metal complexes which can enter the environment.

  8. Activated carbon monoliths for methane storage

    NASA Astrophysics Data System (ADS)

    Chada, Nagaraju; Romanos, Jimmy; Hilton, Ramsey; Suppes, Galen; Burress, Jacob; Pfeifer, Peter

    2012-02-01

    The use of adsorbent storage media for natural gas (methane) vehicles allows for the use of non-cylindrical tanks due to the decreased pressure at which the natural gas is stored. The use of carbon powder as a storage material allows for a high mass of methane stored for mass of sample, but at the cost of the tank volume. Densified carbon monoliths, however, allow for the mass of methane for volume of tank to be optimized. In this work, different activated carbon monoliths have been produced using a polymeric binder, with various synthesis parameters. The methane storage was studied using a home-built, dosing-type instrument. A monolith with optimal parameters has been fabricated. The gravimetric excess adsorption for the optimized monolith was found to be 161 g methane for kg carbon.

  9. Characterization of coal and charcoal by alpha-particle and gamma-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Carrasco Lourtau, A. M.; Rubio Montero, M. P.; Jurado Vargas, M.

    2015-11-01

    Although coal and charcoal have similar physical and chemical characteristics, there are several crystallographic procedures used to distinguish and characterize them. But if the matrix is crushed, there is no standard procedure to distinguish coal from charcoal. In this work, a procedure to characterize coal and charcoal samples based on the radioactive content is proposed. The first assay is by gamma-ray spectrometry, which allows a part of the radioactive content to be determined rapidly and non-destructively. Then, alpha-particle spectrometry is applied to assay the content of those radionuclides which are difficult to determine precisely by gamma-ray spectrometry. This second technique requires prior chemical purification of the carbon sample in order to separate the corresponding radionuclides of interest.

  10. The pH-dependent adsorption of tributyltin to charcoals and soot.

    PubMed

    Fang, Liping; Borggaard, Ole K; Marcussen, Helle; Holm, Peter E; Bruun Hansen, Hans Christian

    2010-12-01

    Widespread use of tributyltin (TBT) poses a serious environmental problem. Adsorption by black carbon (BC) may strongly affect its behavior. The adsorption of TBT to well characterized soot and two charcoals with specific surface area in the range of 62-111m(2)g(-1) have been investigated with main focus on pH effects. The charcoals but not soot possess acidic functional groups. TBT adsorption reaches maximum at pH 6-7 for charcoals, and at pH>6 for soot. Soot has between 1.5 and 15 times higher adsorption density (0.09-1.77μmolm(-2)) than charcoals, but charcoals show up to 17 times higher sorption affinities than soot. TBT adsorption is successfully described by a new pH-dependent dual Langmuir model considering electrostatic and hydrophobic adsorption, and pH effects on TBT speciation and BC surface charge. It is inferred that strong sorption of the TBTOH species to BC may affect TBT toxicity.

  11. The Preparation and Reduction Behavior of Charcoal Composite Iron Oxide Pellets

    NASA Astrophysics Data System (ADS)

    Konishi, Hirokazu; Usui, Tateo; Harada, Takeshi

    In the energy conversion, biomass has novel advantage, i.e., no CO2 emission, because of carbon neutral. Charcoal composite iron oxide pellets were proposed to decrease CO2 emission for the ironmaking. These pellets were promising to decrease the initial temperature for reduction reaction of carbon composite iron ore agglomerate under a rising temperature condition, such as in a blast furnace shaft. In order to obtain charcoal, Japanese cedar and cypress were carbonized from room temperature to maximum carbonization temperature (TC, max = 1273 K) at a heating rate of 200 K/h, and kept at TC, max until arrival time of 6 h. Reducing gases of CO and CH4 started releasing from relatively low temperature (500 K). In the total gas volume of carbonization, H2 gas of Japanese cedar was more than that of Japanese cypress. These woods have more CO gas volume than Newcastle blend coal has. The obtained charcoal was mixed with reagent grade hematite in the mass ratio of one to four. Then, a small amount of Bentonite was added to the mixture as a binder, and the charcoal composite iron oxide pellets were prepared and reduced at 1273, 1373 and 1473 K in nitrogen gas atmosphere. It was conirmed by the generated gas analysis during reduction reaction that charcoal composite iron oxide pellets had higher reducibility than char composite pellets using Newcastle blend coal. From the XRD analysis of the reduced pellets, it was found that the original Fe2O3 was almost reduced to Fe for 60 min at 1273 K, 20 min at 1373 K and 5~15 min at 1473 K.

  12. The Charcoal Trap: Miombo woodlands versus the energy needs of people

    NASA Astrophysics Data System (ADS)

    Merbold, Lutz; Maurice, Muchinda; Mukufute M, Mukelabai; J, Scholes Robert; Waldemar, Ziegler; L, Kutsch Werner

    2010-05-01

    Miombo woodlands cover the transition zone between the dry open savannas and the moist forests in Southern Africa and occupy the vast area of 2.7 Mio km2. These ecosystems are highly disturbed by deforestation, mostly for charcoal production. Charcoal has become the largest source to satisfy urban energy demands. Even though when charcoal is a less energy-efficient fuel compared to firewood but by having higher energy densities and thus being cheaper to transport. Over the last decades, charcoal production has become a full-time employment for migrant workers, resulting in very different and no longer sustainable deforestation patterns. Strategies to reduce the pressure on the miombo woodlands have to take aspects of employment and energy demand into account. The objectives of the study were to examine above- and belowground carbon losses from an intact miombo woodland (protected forest reserve) in comparison to a highly disturbed surrounding area due to charcoal production. Detection of changes in carbon concentrations and stocks were made possible by applying biomass- and soil inventories as well as the eddy-covariance method. These local results were up-scaled to countrywide estimates of carbon lost to the atmosphere by deforestation in addition to carbon losses fossil fuel combustion. The results show, that in the worst case scenario which does not assume any regeneration, a developing country as Zambia, can easily emit as much carbon per capita as a developed Western world country such as France, when deforestation is included in the national inventory (up to 9.1 t of CO2 per capita). However, regeneration is very probably when post-harvest disturbance is low. Further studies on miombo regeneration are highly demanded.

  13. Chemical and Isotopic Thresholds in Charring: Implications for the Interpretation of Charcoal Mass and Isotopic Data

    NASA Astrophysics Data System (ADS)

    Pyle, L.; Hockaday, W. C.; Boutton, T. W.; Zygourakis, K.; Kinney, T.; Masiello, C. A.

    2014-12-01

    Charcoal plays a significant role in the long-term carbon cycle and its use as a soil amendment is becoming a viable carbon sequestration strategy (biochar). One challenge in this research area has been comparing results between studies in part due to the diversity of lab and field production conditions. Although the highest treatment temperature (HTT) is often used to describe pyrolysis conditions, several studies have shown that length of time at the highest temperature can also cause changes to the physicochemical qualities of charcoal and ignoring this effect may introduce inter-comparison problems. Addressing this issue becomes especially important in the discussion of optimizing biochar for soil remediation and carbon sequestration, and in discussions of charcoal use in reconstructing past fire regimes, as increasing time at temperature may cause changes in charcoal properties similar to the changes caused by increasing HTT. Here we introduce a formal definition of charring intensity (CI) to more accurately characterize pyrolysis, and we document variation in this property with pyrolysis temperature and reaction duration. We found two types of responses to CI: either a linear or a threshold relationship. We show that a threshold exists where %C, %N and δ15N begin exhibiting large changes, and this CI threshold co-occurred with an increase in charcoal aromaticity. Mass yield decreased linearly with charring intensity and carbon isotopes did not change from original biomass values in our controlled laboratory experiments. Analysis of these data shows that pyrolysis parameters should be defined in the literature as a combination of temperature and duration conditions, and that biomass that has undergone pyrolysis may be influencing soil organic nitrogen. Additionally, the lack of alteration in carbon isotopes across our matrix supports the efficacy of using pyrolyzed material for archaeological reconstructions.

  14. Novel application of confocal laser scanning microscopy and 3D volume rendering toward improving the resolution of the fossil record of charcoal.

    PubMed

    Belcher, Claire M; Punyasena, Surangi W; Sivaguru, Mayandi

    2013-01-01

    Variations in the abundance of fossil charcoals between rocks and sediments are assumed to reflect changes in fire activity in Earth's past. These variations in fire activity are often considered to be in response to environmental, ecological or climatic changes. The role that fire plays in feedbacks to such changes is becoming increasingly important to understand and highlights the need to create robust estimates of variations in fossil charcoal abundance. The majority of charcoal based fire reconstructions quantify the abundance of charcoal particles and do not consider the changes in the morphology of the individual particles that may have occurred due to fragmentation as part of their transport history. We have developed a novel application of confocal laser scanning microscopy coupled to image processing that enables the 3-dimensional reconstruction of individual charcoal particles. This method is able to measure the volume of both microfossil and mesofossil charcoal particles and allows the abundance of charcoal in a sample to be expressed as total volume of charcoal. The method further measures particle surface area and shape allowing both relationships between different size and shape metrics to be analysed and full consideration of variations in particle size and size sorting between different samples to be studied. We believe application of this new imaging approach could allow significant improvement in our ability to estimate variations in past fire activity using fossil charcoals.

  15. Preparation of activated carbons with mesopores by use of organometallics

    SciTech Connect

    Yamada, Yoshio; Yoshizawa, Noriko; Furuta, Takeshi

    1996-12-31

    Activated carbons are commercially produced by steam or CO{sub 2} activation of coal, coconut shell and so on. In general the carbons obtained give pores with a broad range of distribution. The objective of this study was to prepare activated carbons from coal by use of various organometallic compounds. The carbons were evaluated for pore size by nitrogen adsorption experiments.

  16. The Charcoal Trap: Miombo Woddlands and the Energy Demands of People

    NASA Astrophysics Data System (ADS)

    Kutsch, W. L.; Merbold, L.; Mukelabai, M. M.

    2012-04-01

    Miombo woodlands cover the transition zone between dry open savannas and moist forests in Southern Africa. They cover about 2.7 million km2 in southern Africa and provide many ecosystem services that support rural life, including medical products, wild foods, construction timber and fuel. In Zambia, as in many of its neighbouring countries, miombo woodlands are currently experiencing accelerating degradation and clearing, mostly with charcoal production as the initial driver. Domestic energy needs in the growing urban areas are largely satisfied by charcoal, which is less energy-efficient fuel on a tree-to-table basis than the firewood that is used in rural areas, but has a higher energy density and is thus cheaper to transport. This study uses data from inventories and from eddy covariance measurements of carbon exchange to characterize the impact of charcoal production on miombo woodlands. We address the following questions: (i) how much carbon is lost at local as well as at national scale and (ii) does forest degradation result in the loss of a carbon sink? On the basis of our data we (iii) estimate the per capita emissions through deforestation and forest degradation in Zambia and relate it to fossil fuel emissions. Furthermore, (iv) a rough estimate of the energy that is provided by charcoal production to private households at a national level is calculated and (v) options for alternative energy supply to private households are discussed.

  17. The charcoal trap: Miombo forests and the energy needs of people

    PubMed Central

    2011-01-01

    Background This study evaluates the carbon dioxide and other greenhouse gas fluxes to the atmosphere resulting from charcoal production in Zambia. It combines new biomass and flux data from a study, that was conducted in a miombo woodland within the Kataba Forest Reserve in the Western Province of Zambia, with data from other studies. Results The measurements at Kataba compared protected area (3 plots) with a highly disturbed plot outside the forest reserve and showed considerably reduced biomass after logging for charcoal production. The average aboveground biomass content of the reserve (Plots 2-4) was around 150 t ha-1, while the disturbed plot only contained 24 t ha-1. Soil carbon was not reduced significantly in the disturbed plot. Two years of eddy covariance measurements resulted in net ecosystem exchange values of -17 ± 31 g C m-2 y-1, in the first and 90 ± 16 g C m-2 in the second year. Thus, on the basis of these two years of measurement, there is no evidence that the miombo woodland at Kataba represents a present-day carbon sink. At the country level, it is likely that deforestation for charcoal production currently leads to a per capita emission rate of 2 - 3 t CO2 y-1. This is due to poor forest regeneration, although the resilience of miombo woodlands is high. Better post-harvest management could change this situation. Conclusions We argue that protection of miombo woodlands has to account for the energy demands of the population. The production at national scale that we estimated converts into 10,000 - 15,000 GWh y-1 of energy in the charcoal. The term "Charcoal Trap" we introduce, describes the fact that this energy supply has to be substituted when woodlands are protected. One possible solution, a shift in energy supply from charcoal to electricity, would reduce the pressure of forests but requires high investments into grid and power generation. Since Zambia currently cannot generate this money by itself, the country will remain locked in the

  18. Making Activated Carbon for Storing Gas

    NASA Technical Reports Server (NTRS)

    Wojtowicz, Marek A.; Serio, Michael A.; Suuberg, Eric M.

    2005-01-01

    Solid disks of microporous activated carbon, produced by a method that enables optimization of pore structure, have been investigated as means of storing gas (especially hydrogen for use as a fuel) at relatively low pressure through adsorption on pore surfaces. For hydrogen and other gases of practical interest, a narrow distribution of pore sizes <2 nm is preferable. The present method is a variant of a previously patented method of cyclic chemisorption and desorption in which a piece of carbon is alternately (1) heated to the lower of two elevated temperatures in air or other oxidizing gas, causing the formation of stable carbon/oxygen surface complexes; then (2) heated to the higher of the two elevated temperatures in flowing helium or other inert gas, causing the desorption of the surface complexes in the form of carbon monoxide. In the present method, pore structure is optimized partly by heating to a temperature of 1,100 C during carbonization. Another aspect of the method exploits the finding that for each gas-storage pressure, gas-storage capacity can be maximized by burning off a specific proportion (typically between 10 and 20 weight percent) of the carbon during the cyclic chemisorption/desorption process.

  19. Adsorption of Hydantoins on Activated Carbon,

    DTIC Science & Technology

    1985-05-01

    performed for single solute, bisolute, and trisolute solutions as well as an undiluted coal gasification wastewater containing predominantly hydantoin...hydantoin, 5,5-dimethylhydantoin, and 5-ethyl-5-methylhydantoin. Absorption using activated carbon did not appear to be an effective treatment process for the removal of hydantoins from the coal gasification wastewater.

  20. ENGINEERING BULLETIN: GRANULAR ACTIVATED CARBON TREATMENT

    EPA Science Inventory

    Granular activated carbon (GAC) treatment is a physicochemical process that removes a wide variety of contaminants by adsorbing them from liquid and gas streams [1, p. 6-3]. This treatment is most commonly used to separate organic contaminants from water or air; however, it can b...

  1. USING POWDERED ACTIVATED CARBON: A CRITICAL REVIEW

    EPA Science Inventory

    Because the performance of powdered activated carbon (PAC) for uses other than taste and odor control is poorly documented, the purpose of this article is to critically review uses that have been reported (i.e., pesticides and herbicides, synthetic organic chemicals, and trihalom...

  2. MODELING MERCURY CONTROL WITH POWDERED ACTIVATED CARBON

    EPA Science Inventory

    The paper presents a mathematical model of total mercury removed from the flue gas at coal-fired plants equipped with powdered activated carbon (PAC) injection for Mercury control. The developed algorithms account for mercury removal by both existing equipment and an added PAC in...

  3. Calibration of diffusion barrier charcoal detectors and application to radon sampling in dwellings

    NASA Astrophysics Data System (ADS)

    Cabrera, M. E. M.; Sujo, L. C.; Villalba, L.; Peinado, J. S.; Jimenez, A. C.; Baca, A. M.; Gandara, S. D.; Villalobos, M. R.; Miranda, A. L.; Peraza, E. F. H.

    2003-10-01

    Some calibration conditions of diffusion barrier charcoal canister (DBCC) detectors for measuring radon concentration in air were studied. A series of functional expressions and graphs were developed to describe relationship between radon concentration in air and the activity adsorbed in DBCC, when placed in small chambers. A semi-empirical expression for the DBCC calibration was obtained, based on the detector integration time and the adsorption coefficient of radon on activated charcoal. Both, the integration time for 10% of DBCC of the same batch, and the adsorption coefficient of radon for the activated charcoal used in these detectors, were experimentally determined. Using these values as the calibration parameters, a semi-empirical calibration function was used for the interpretation of the radon activities in the detectors used for sampling more than 200 dwellings in the major cities of the state of Chihuahua, Mexico.

  4. Removal of ethylenthiourea and 1,2,4-triazole pesticide metabolites from water by adsorption in commercial activated carbons.

    PubMed

    Amorim, Camila C; Bottrel, Sue Ellen C; Costa, Elizângela P; Teixeira, Ana Paula C; Leão, Mônica M D

    2013-01-01

    This study evaluated the adsorption capacity of ethylenthiourea (ETU) and 1H-1,2,4-triazole (1,2,4-T) for two commercial activated carbons: charcoal-powdered activated carbon (CPAC) and bovine bone-powdered activated carbon (BPAC). The tests were conducted at a bench scale, with ETU and 1,2,4-T diluted in water, for isotherm and adsorption kinetic studies. The removal of the compounds was accompanied by a total organic carbon (TOC) analysis and ultraviolet (UV) reduction analysis. The coals were characterized by their surface area using nitrogen adsorption/desorption, by a scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS) and by a zero charge point analysis (pHpcz). The results showed that adsorption kinetics followed a pseudo-second-order model for both coals, and the adsorption isotherms for CPAC and BPAC were adjusted to the Langmuir and Freundlich isotherms, respectively. The CPAC removed approximately 77% of the ETU and 76% of the 1,2,4-T. The BPAC was ineffective at removing the contaminants.

  5. Recovery of Technetium Adsorbed on Charcoal

    SciTech Connect

    Engelmann, Mark D.; Metz, Lori A.; Ballou, Nathan E.

    2006-05-01

    Two methods capable of near complete recovery of technetium adsorbed on charcoal are presented. The first involves liquid extraction of the technetium from the charcoal by hot 4M nitric acid. An average recovery of 98% (n=3) is obtained after three rounds of extraction. The second method involves dry ashing with air in a quartz combustion tube at 400-450 C. This method yields an average recovery of 96% (n=5). Other thermal methods were attempted, but resulted in reduced recovery and incomplete material balance

  6. Evaluation on estrogenicity and oxidative hepatotoxicity of fossil fuel industrial wastewater before and after the powdered activated carbon treatment.

    PubMed

    Chen, Fu-An; Shue, Meei-Fang; Chen, Ting-Chien

    2004-06-01

    There are 10 manufacturers who produce fossil fuel products in the Da-Hse Industrial District, Kaohsiung County, southwestern Taiwan. Before discharging the wastewater into the nearby aquatic environment, the pretreated wastewater from these manufacturers must be processed in a treatment plant which includes four major processing units: equalization, a primary clarifier, an aeration basin, and a final clarifier. In order to estimate the potential environmental risks of industrial wastewater from each manufacturer and the treatment efficiency of the powdered activated carbon treatment (PACT) system used in this wastewater treatment plant, in vitro bioassays for estrogenicity and oxidative hepatotoxicity were carried out using a stably transfected human breast cancer cell line, MVLN, and a human hepatocellular carcinoma cell line, HepG2, respectively. Estrogenic substances occurred in nine of 10 pretreated wastewaters from these manufacturers in which the relative luciferase activity ranged from 18.9% to 98.0% for 1-fold-condensed wastewaters corresponding to the concentration of the original wastewater. The estrogenicity was highest at the influent of the treatment plant and decreased through the treatment process. About 81% estrogenicity clearance was found through all processing units. On the other hand, oxidative hepatotoxic substances existed in seven of 10 pretreated wastewaters from these manufacturers in which relative TBARs activity ranged from 18.5% to 43.0% for 1-fold-condensed wastewater. The TBARs of influent samples apparently decreased through the processing units until the aeration basin, but abruptly rose in the final clarifier, which was a result of the addition of an active charcoal-retrieving agent with the molecular formula of (C(2)H(3))(n)CONHCH(2)N(CH(3))(3)Cl and which had high TBARs activity. No TBARs activity being found in effluent samples could be a consequence of allowing sufficient time for coagulation between the active charcoal and its

  7. Chemical recalcitrance of biochar and wildfire charcoal: how similar are they?

    NASA Astrophysics Data System (ADS)

    Santin, Cristina; Doerr, Stefan H.; Merino, Agustin

    2016-04-01

    The enhanced chemical resistance to biological degradation of pyrogenic materials, either produced during wildfires (charcoal) or by man (biochar), makes them long-term carbon sinks once incorporated in soils. In spite of their fundamental similarities, studies comparing the chemical recalcitrance of biochar and wildfire charcoal are scarce because analogous materials for accurate comparison are not easily available. Using solid-state 13C cross polarization-magic angle spinning nuclear magnetic resonance spectroscopy we characterized the chemical recalcitrance of pyrogenic materials generated from the same unburnt feedstooks (litter and dead wood from Pinus banksiana): (a) charcoal from a high-intensity wildfire and (b) biochar obtained by slow pyrolysis [3 treatments: 2 h at 350, 500 and 650°C]. For quantification, the spectra were divided into four regions representing different chemical environments of the 13C nucleus: alkyl C (0-45 ppm), O-alkyl C (45-110 ppm), olefinic and aromatic C(110-160 ppm), and carbonyl C (160-210 ppm). As an indicator of chemical recalcitrance, the degree of aromaticity (%) was calculated as follow: aromatic-C ∗ 100 / (alkyl C+ O alkyl-C + aromatic-C). The pyrogenic materials derived from wood show higher degrees of aromaticity (68 to 88%) than pyrogenic material derived from litter (40 to 88%). When comparing biochar and wildfire charcoal, biochars produced at 500 and 650°C always have higher degrees of aromaticity than wildfire charcoals, irrespective of the original feedstock. Wildfire charcoals always show a more heterogeneous chemical composition, with alkyl and O-alkyl compounds present even in charcoal generated at very high temperatures (temperatures up to 950 °C were recorded on the litter surface during the wildfire). However, biochars produced at 500 and 650 °C are mostly aromatic, and only the biochars produced at 350 °C show partial contribution of alkyl-C compounds. Our results suggest that biochar-type pyrogenic

  8. Determination of 63Ni and 59Ni in spent ion-exchange resin and activated charcoal from the IEA-R1 nuclear research reactor.

    PubMed

    Taddei, M H T; Macacini, J F; Vicente, R; Marumo, J T; Sakata, S K; Terremoto, L A A

    2013-07-01

    A radiochemical method has been adapted to determine (59)Ni and (63)Ni in samples of radioactive wastes from the water cleanup system of the IEA-R1 nuclear research reactor. The process includes extraction chromatographic resin with dimethylglyoxime (DMG) as a functional group. Activity concentrations of (59)Ni and (63)Ni were measured, respectively, by X-ray spectrometry and liquid scintillation counting, whereas the chemical yield was determined by ICP-OES. The average ratio of measured activity concentrations of (63)Ni and (59)Ni agree well with theory.

  9. Supercapacitor Electrodes from Activated Carbon Monoliths and Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Dolah, B. N. M.; Othman, M. A. R.; Deraman, M.; Basri, N. H.; Farma, R.; Talib, I. A.; Ishak, M. M.

    2013-04-01

    Binderless monoliths of supercapacitor electrodes were prepared by the carbonization (N2) and activation (CO2) of green monoliths (GMs). GMs were made from mixtures of self-adhesive carbon grains (SACG) of fibers from oil palm empty fruit bunches and a combination of 5 & 6% KOH and 0, 5 & 6% carbon nanotubes (CNTs) by weight. The electrodes from GMs containing CNTs were found to have lower specific BET surface area (SBET). The electrochemical behavior of the supercapacitor fabricated using the prepared electrodes were investigated by electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge (GCD). In general an addition of CNTs into the GMs reduces the equivalent series resistance (ESR) value of the cells. A cell fabricated using electrodes from GM with 5% CNT and 5% KOH was found to have the largest reduction of ESR value than that from the others GMs containing CNT. The cell has steeper Warburg's slope than that from its respective non-CNT GM, which reflect the smaller resistance for electrolyte ions to move into pores of electrodes despite these electrodes having largest reduction in specific BET surface area. The cell also has the smallest reduction of specific capacitance (Csp) and maintains the specific power range despite a reduction in the specific energy range due to the CNT addition.

  10. Cooperative redox activation for carbon dioxide conversion

    NASA Astrophysics Data System (ADS)

    Lian, Zhong; Nielsen, Dennis U.; Lindhardt, Anders T.; Daasbjerg, Kim; Skrydstrup, Troels

    2016-12-01

    A longstanding challenge in production chemistry is the development of catalytic methods for the transformation of carbon dioxide into useful chemicals. Silane and borane promoted reductions can be fined-tuned to provide a number of C1-building blocks under mild conditions, but these approaches are limited because of the production of stoichiometric waste compounds. Here we report on the conversion of CO2 with diaryldisilanes, which through cooperative redox activation generate carbon monoxide and a diaryldisiloxane that actively participate in a palladium-catalysed carbonylative Hiyama-Denmark coupling for the synthesis of an array of pharmaceutically relevant diarylketones. Thus the disilane reagent not only serves as the oxygen abstracting agent from CO2, but the silicon-containing `waste', produced through oxygen insertion into the Si-Si bond, participates as a reagent for the transmetalation step in the carbonylative coupling. Hence this concept of cooperative redox activation opens up for new avenues in the conversion of CO2.

  11. The biomass derived activated carbon for supercapacitor

    NASA Astrophysics Data System (ADS)

    Senthilkumar, S. T.; Selvan, R. Kalai; Melo, J. S.

    2013-06-01

    In this work, the activated carbon was prepared from biowaste of Eichhornia crassipes by chemical activation method using KOH as the activating agent at various carbonization temperatures (600 °C, 700 °C and 800 °C). The disordered nature, morphology and surface functional groups of ACs were examined by XRD, SEM and FT-IR. The electrochemical properties of AC electrodes were studied in 1M H2SO4 in the potential range of -0.2 to 0.8 V using cyclic voltammetry (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS) techniques in a three electrode system. Subsequently, the fabricated supercapacitor using AC electrode delivered the higher specific capacitance and energy density of 509 F/g at current density of 1 mA/cm2 and 17 Wh/kg at power density of 0.416 W/g.

  12. Charcoal from the pyrolysis of rapeseed plant straw-stalk

    SciTech Connect

    Karaosmanoglu, F.; Tetik, E.

    1999-07-01

    Charcoal is an important product of pyrolysis of biomass sources. Charcoal can be used for domestic, agricultural, metallurgical, and chemical purposes. In this study different characteristics of charcoal, one of the rape seed plant straw-stalk pyrolysis product, was researched and presented as candidates.

  13. Emissions of air pollutants from indoor charcoal barbecue.

    PubMed

    Huang, Hsiao-Lin; Lee, Whei-May Grace; Wu, Feng-Shu

    2016-01-25

    Ten types of commercial charcoal commonly used in Taiwan were investigated to study the potential health effects of air pollutants generated during charcoal combustion in barbecue restaurants. The charcoal samples were combusted in a tubular high-temperature furnace to simulate the high-temperature charcoal combustion in barbecue restaurants. The results indicated that traditional charcoal has higher heating value than green synthetic charcoal. The amount of PM10 and PM2.5 emitted during the smoldering stage increased when the burning temperature was raised. The EF for CO and CO2 fell within the range of 68-300 and 644-1225 g/kg, respectively. Among the charcoals, the lowest EF for PM2.5 and PM10 were found in Binchōtan (B1). Sawdust briquette charcoal (I1S) emitted the smallest amount of carbonyl compounds. Charcoal briquettes (C2S) emitted the largest amount of air pollutants during burning, with the EF for HC, PM2.5, PM10, formaldehyde, and acetaldehyde being the highest among the charcoals studied. The emission of PM2.5, PM10, formaldehyde, and acetaldehyde were 5-10 times those of the second highest charcoal. The results suggest that the adverse effects of the large amounts of air pollutants generated during indoor charcoal combustion on health and indoor air quality must not be ignored.

  14. Anthropogenic Charcoal Deposits: Analogues for the Long-Term Functioning and Stability of Biochar in European Soils?

    NASA Astrophysics Data System (ADS)

    Mugford, Ian; Street-Perrot, Alayne; Santín, Cristina; Denman, Huw

    2014-05-01

    Anthropogenic charcoal deposits, characterised by thick charcoal-rich soil horizons, offer an invaluable Late Quaternary record of pyrogenic carbon (PyC) additions to soils. A traditional source of archaeological, anthracological and palaeoecological data, the potential contribution of anthropogenic charcoal deposits to soil science and assessment of carbon (C) sequestration is often overlooked. If addition of biochar to soils is to form a key component of a low-C economy, crucial questions must be addressed relating to its longevity and behaviour in the soil environment. With rare exceptions, previous studies have focussed on short-term incubation experiments and field or pot trials, often neglecting important natural soil and environmental processes. This study addresses these issues by comparing the physicochemical properties of European anthropogenic charcoal-rich deposits, with 14C ages ranging from > 43 ka to Modern, to native soils (nearby control sites). We will present results from a study of 23 charcoal-rich soil cores, collected from a 'Pre-historic' ditch mound, a Bronze Age burnt mound, a Roman furnace, and post-mediaeval and Modern Meilers, situated along a climatic gradient from Mediterranean (Southern Italy) to Humid Temperate (South Wales). The ability of charcoal to alter fertility and retain plant-available nutrients was assessed by measuring soil cation- exchange capacity. Retention of refractory C by the charcoal deposits was evaluated from their total organic C (TOC) contents, atomic H:C and O:C ratios, and residues after acid- dichromate oxidation. Picked charcoal fragments were also compared with modern biochars and biomass using: 1) their thermogravimetric recalcitrance (R50) indices (Harvey et al. 2012); and 2) attenuated total reflectance (ATR) FT-IR data, to gauge the development of functional groups linked to the long-term oxidation of the particle surfaces. Radiocarbon dating was used to assess the ages of the deposits. Our study

  15. Evaluation of methods used to desorb the constituents adsorbed on the charcoal contained in automotive evaporative canisters. Part 1

    SciTech Connect

    Dropkin, D.

    1990-02-01

    The study evaluates current extraction methods for analyzing charcoal canisters which are used to control evaporative emissions in automobiles. The initial phase of the study investigated various extraction procedures and solvents, including carbon disulfide, methanol, cyclohexane, methylene chloride, and a mixture containing carbon disulfide and 12% acetone. The solvents were used in the soxhlet extraction of evaporative hydrocarbons adsorbed on the charcoal of the canister. In another procedure the charcoal was subjected to ultrasonication with carbon disulfide as the extraction solvent. The various sample extracts were analyzed for detailed hydrocarbon by gas chromatography and results of the procedures were compared. The difference between the results of the soxhlet extractions in the study and those in the previous study was that there had been a significant increase in the quantity of aromatics measured. The differences in the procedures for sample introduction into the GC was determined to result in fewer measurable hydrocarbons in the prior study.

  16. Effects of Weathering on Impregnated Charcoal Performance.

    DTIC Science & Technology

    1981-09-01

    4 A mixture of elemental iodine (0.5 wt.%) and an S" activated carbon (BC Type 177) from coconut shells was heated (6.70 C/min) in a flow of purified...Penetration of 1 3 1 ICH3 at 21°C for new (not used) Coconut Shell Commercial Carbons (impregnated) With and Without Prehumidification...Mixture of Elemental Iodine and Non-impregnated Coconut Activated Carbon . (Note: Y coordinate is logarithmic)... 87 29. Formation of Organic Iodides

  17. A Biomedical Application of Activated Carbon Adsorption: An Experiment Using Acetaminophen and N-Acetylcysteine.

    ERIC Educational Resources Information Center

    Rybolt, Thomas R.; And Others

    1988-01-01

    Illustrates an interesting biomedical application of adsorption from solution and demonstrates some of the factors that influence the in vivo adsorption of drug molecules onto activated charcoal. Uses acetaminophen and N-acetylcysteine for the determination. Suggests several related experiments. (MVL)

  18. Late Quaternary stratigraphic charcoal records from Madagascar

    NASA Astrophysics Data System (ADS)

    Burney, David A.

    1987-09-01

    The classic view regarding the cause of the extinction of at least 17 species of large mammals, birds, and reptiles in Madagascar during the late Holocene implicates human use of fire to modify the environment. However, analysis of the charcoal stratigraphy of three sediment cores from Madagascar shows that late Pleistocene and early- to mid-Holocene sediments deposited prior to human settlement often contain more charcoal than postsettlement and modern sediments. This observation, which is confirmed by independent measurements from direct assay and palynological counting techniques, suggests that widely held but previously untested beliefs concerning the importance of anthropogenic fires in late Holocene environmental changes and megafaunal extinctions of Madagascar may be based on an overly simplified version of actual prehistoric conditions. Moderate to low charcoal values characterized only the late Holocene millennia immediately prior to the presumed time of arrival of the first settlers. Human settlement is probably indicated in the stratigraphy by the sharp rise in charcoal content observed beginning ca. 1500 yr B.P. Fire appears to be a significant natural component of prehuman environments in Madagascar, but some factor, probably climate, has modulated the extent of natural burning.

  19. Sawdust and Charcoal: Fuel for Raku.

    ERIC Educational Resources Information Center

    Brisson, Harriet E.

    1980-01-01

    Raku is an ancient Japanese process of firing pottery in which the bisqued piece is glazed and placed in a preheated kiln. Described are the benefits of substituting sawdust and charcoal for firing pottery by those people who do not have access to a kiln. (KC)

  20. Carbon nanomaterials: Biologically active fullerene derivatives.

    PubMed

    Bogdanović, Gordana; Djordjević, Aleksandar

    2016-01-01

    Since their discovery, fullerenes, carbon nanotubes, and graphene attract significant attention of researches in various scientific fields including biomedicine. Nano-scale size and a possibility for diverse surface modifications allow carbon nanoallotropes to become an indispensable nanostructured material in nanotechnologies, including nanomedicine. Manipulation of surface chemistry has created diverse populations of water-soluble derivatives of fullerenes, which exhibit different behaviors. Both non-derivatized and derivatized fullerenes show various biological activities. Cellular processes that underline their toxicity are oxidative, genotoxic, and cytotoxic responses.The antioxidant/cytoprotective properties of fullerenes and derivatives have been considered in the prevention of organ oxidative damage and treatment. The same unique physiochemical properties of nanomaterials may also be associated with potential health hazards. Non-biodegradability and toxicity of carbon nanoparticles still remain a great concern in the area of biomedical application. In this review, we report on basic physical and chemical properties of carbon nano-clusters--fullerenes, nanotubes, and grapheme--their specificities, activities, and potential application in biological systems. Special emphasis is given to our most important results obtained in vitro and in vivo using polyhydroxylated fullerene derivative C₆₀(OH)₂₄.

  1. Experimental Research of Pyrolysis Gases Cracking on Surface of Charcoal

    NASA Astrophysics Data System (ADS)

    Kosov, Valentin; Kosov, Vladimir; Zaichenko, Victor

    For several years, in the Joint Institute for High Temperatures of Russian Academy of Sciences, two-stage technology of biomass processing has been developing [1]. The technology is based on pyrolysis of biomass as the first stage. The second stage is high-temperature conversion of liquid fraction of the pyrolysis on the surface of porous charcoal matrix. Synthesis gas consisted of carbon monoxide and hydrogen is the main products of the technology. This gas is proposed to be used as fuel for gas-engine power plant. For practical implementation of the technology it is important to know the size of hot char filter for full cracking of the pyrolysis gases on the surface of charcoal. Theoretical determination of the cracking parameters of the pyrolysis gases on the surface of coal is extremely difficult because the pyrolysis gases include tars, whose composition and structure is complicated and depends on the type of initial biomass. It is also necessary to know the surface area of the char used in the filter, which is also a difficult task. Experimental determination of the hot char filter parameters is presented. It is shown that proposed experimental method can be used for different types of biomass.

  2. Effects on the efficiency of activated carbon on exposure to welding fumes

    SciTech Connect

    Ghosh, D.

    1995-02-01

    It is the intention of this paper to document that certain types of welding fumes have little or no effect on the effectiveness of the carbon filter air filtration efficiency when directly exposed to a controlled amount of welding fumes for a short-term period. The welding processes studied were restricted to shielded metal arc welding (SMAW), flux cored arc welding (FCAW), gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) processes. Contrary to the SMAW and FCAW processes, the GTAW (or TIG) and the GMAW (or MIG) welding processes do not require the use of flux as part of the overall process. Credit was taken for these processes occurring in inert gas environments and producing minimal amount of smoke. It was concluded that a study involving the SMAW process would also envelop the effects of the TIG and MIG welding processes. The quantity of welding fumes generated during the arc welding process is a function of the particular process, the size and type of electrode, welding machine amperage, and operator proficiency. For this study, the amount of welding for specific testing was equated to the amount of welding normally conducted during plant unit outages. Different welding electrodes were also evaluated, and the subsequent testing was limited to an E7018 electrode which was judged to be representative of all carbon and stainless steel electrodes commonly used at the site. The effect of welding fumes on activated charcoal was tested using a filtration unit complete with prefilters, upstream and downstream high efficiency particulate air (HEPA) filters, and a carbon adsorber section. The complete system was field tested in accordance with ANSI N510 standards prior to exposing the filters and the adsorber bed to welding fumes. The carbon samples were tested at an established laboratory using ASTM D3803-1989 standards.

  3. Enhanced capacitive properties of commercial activated carbon by re-activation in molten carbonates

    NASA Astrophysics Data System (ADS)

    Lu, Beihu; Xiao, Zuoan; Zhu, Hua; Xiao, Wei; Wu, Wenlong; Wang, Dihua

    2015-12-01

    Simple, affordable and green methods to improve capacitive properties of commercial activated carbon (AC) are intriguing since ACs possess a predominant role in the commercial supercapacitor market. Herein, we report a green reactivation of commercial ACs by soaking ACs in molten Na2CO3-K2CO3 (equal in mass ratios) at 850 °C combining the merits of both physical and chemical activation strategies. The mechanism of molten carbonate treatment and structure-capacitive activity correlations of the ACs are rationalized. Characterizations show that the molten carbonate treatment increases the electrical conductivity of AC without compromising its porosity and wettability of electrolytes. Electrochemical tests show the treated AC exhibited higher specific capacitance, enhanced high-rate capability and excellent cycle performance, promising its practical application in supercapacitors. The present study confirms that the molten carbonate reactivation is a green and effective method to enhance capacitive properties of ACs.

  4. Kinetics of adsorption with granular, powdered, and fibrous activated carbon

    SciTech Connect

    Shmidt, J.L.; Pimenov, A.V.; Lieberman, A.I.; Cheh, H.Y.

    1997-08-01

    The properties of three different types of activated carbon, fibrous, powdered, and granular, were investigated theoretically and experimentally. The adsorption rate of the activated carbon fiber was found to be two orders of magnitude higher than that of the granular activated carbon, and one order of magnitude higher than that of the powdered activated carbon. Diffusion coefficients of methylene blue in the fibrous, powdered, and granular activated carbons were determined experimentally. A new method for estimating the meso- and macropore surface areas in these carbons was proposed.

  5. Aqueous mercury adsorption by activated carbons.

    PubMed

    Hadi, Pejman; To, Ming-Ho; Hui, Chi-Wai; Lin, Carol Sze Ki; McKay, Gordon

    2015-04-15

    Due to serious public health threats resulting from mercury pollution and its rapid distribution in our food chain through the contamination of water bodies, stringent regulations have been enacted on mercury-laden wastewater discharge. Activated carbons have been widely used in the removal of mercuric ions from aqueous effluents. The surface and textural characteristics of activated carbons are the two decisive factors in their efficiency in mercury removal from wastewater. Herein, the structural properties and binding affinity of mercuric ions from effluents have been presented. Also, specific attention has been directed to the effect of sulfur-containing functional moieties on enhancing the mercury adsorption. It has been demonstrated that surface area, pore size, pore size distribution and surface functional groups should collectively be taken into consideration in designing the optimal mercury removal process. Moreover, the mercury adsorption mechanism has been addressed using equilibrium adsorption isotherm, thermodynamic and kinetic studies. Further recommendations have been proposed with the aim of increasing the mercury removal efficiency using carbon activation processes with lower energy input, while achieving similar or even higher efficiencies.

  6. Fire history in western Patagonia from paired tree-ring fire-scar and charcoal records

    NASA Astrophysics Data System (ADS)

    Holz, A.; Haberle, S.; Veblen, T. T.; de Pol-Holz, R.; Southon, J.

    2012-03-01

    Fire history reconstructions are typically based on tree ages and tree-ring fire scars or on charcoal in sedimentary records from lakes or bogs, but rarely on both. In this study of fire history in western Patagonia (47-48° S) in southern South America (SSA) we compared three sedimentary charcoal records collected in bogs with tree-ring fire-scar data collected at 13 nearby sample sites. We examined the temporal and spatial correspondence between the two fire proxies and also compared them to published charcoal records from distant sites in SSA, and with published proxy reconstructions of regional climate variability and large-scale climate modes. Two of our three charcoal records record fire activity for the last 4 ka yr and one for the last 11 ka yr. For the last ca. 400 yr, charcoal accumulation peaks tend to coincide with high fire activity in the tree-ring fire scar records, but the charcoal records failed to detect some of the fire activity recorded by tree rings. Potentially, this discrepancy reflects low-severity fires that burn in herbaceous and other fine fuels without depositing charcoal in the sedimentary record. Periods of high fire activity tended to be synchronous across sample areas, across proxy types, and with proxy records of regional climatic variability as well as major climate drivers. Fire activity throughout the Holocene in western Patagonia has responded to regional climate variation affecting a broad region of southern South America that is teleconnected to both tropical- and high-latitude climate drivers-El Niño-Southern Oscillation and the Southern Annular Mode. An early Holocene peak in fire activity pre-dates any known human presence in our study area, and consequently implicates lightning as the ignition source. In contrast, the increased fire activity during the 20th century, which was concomitantly recorded by charcoal from all the sampled bogs and at all fire-scar sample sites, is attributed to human-set fires and is outside the

  7. Less-costly activated carbon for sewage treatment

    NASA Technical Reports Server (NTRS)

    Ingham, J. D.; Kalvinskas, J. J.; Mueller, W. A.

    1977-01-01

    Lignite-aided sewage treatment is based on absorption of dissolved pollutants by activated carbon. Settling sludge is removed and dried into cakes that are pyrolyzed with lignites to yield activated carbon. Lignite is less expensive than activated carbon previously used to supplement pyrolysis yield.

  8. 78 FR 13894 - Certain Activated Carbon From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-01

    ... COMMISSION Certain Activated Carbon From China Determination On the basis of the record \\1\\ developed in the... antidumping duty order on certain activated carbon from China would be likely to lead to continuation or... USITC Publication 4381 (February 2013), entitled Certain Activated Carbon from China: Investigation...

  9. Dynamics and functions of bacterial communities in bark, charcoal and sand filters treating greywater.

    PubMed

    Dalahmeh, Sahar S; Jönsson, Håkan; Hylander, Lars D; Hui, Nan; Yu, Dan; Pell, Mikael

    2014-05-01

    This study explored the effects of greywater application on the dynamics and functions of biofilms developed in bark, activated charcoal and sand filters used for removal of organic matter and nitrogen. Duplicate columns (20 cm diameter, 60 cm deep) were packed with bark, charcoal or sand with effective size 1.4 mm and uniformity coefficient 2.2, and dosed with 32 L m(-2) day(-1) of an artificial greywater (14 g BOD5 m(-2) day(-1)) for 116 days. Potential respiration rate (PRR), determined in filter samples after addition of excess glucose, and bacterial diversity and composition, analysed by 454-pyrosequencing of bacterial 16S ribosomal DNA, were measured at different times and depths in the filters. The bark and charcoal filters were more efficient in removing BOD5 than the sand (98, 97% and 75%, respectively). The highest PRR in the 0-2 cm layer of the columns on day 84 was found in the bark filters, followed by the charcoal and sand filters (632 ± 66, 222 ± 34 and 56 ± 2 mg O2 L(-1), respectively; n = 2). Bacterial community in the bark filters showed the highest richness. The charcoal and sand filters both developed more diverse and dynamic (changing over time and depth) bacterial communities than the bark. In addition to the greywater, the lignocelluosic composition of the bark and its lower pH probably selected for the bacterial community structure and the organic content provided additional substrate, as shown by its higher PRR and its different nitrifying bacterial genera. In the oligotrophic charcoal and sand, the composition of the greywater itself defined the bacterial community. Thus, the initially low bacterial biomass in the latter filters was enriched over time, allowing a diversified bacterial community to develop. The top layers of the bark and charcoal filters displayed a high dominance of Rhizobium, Pseudomonas and Acinetobacter, which were less evident in the 60 cm layer, whereas in the sand filters these genera were

  10. Carbon Monoxide Dehydrogenase Activity in Bradyrhizobium japonicum

    PubMed Central

    Lorite, María J.; Tachil, Jörg; Sanjuán, Juán; Meyer, Ortwin; Bedmar, Eulogio J.

    2000-01-01

    Bradyrhizobium japonicum strain 110spc4 was capable of chemolithoautotrophic growth with carbon monoxide (CO) as a sole energy and carbon source under aerobic conditions. The enzyme carbon monoxide dehydrogenase (CODH; EC 1.2.99.2) has been purified 21-fold, with a yield of 16% and a specific activity of 58 nmol of CO oxidized/min/mg of protein, by a procedure that involved differential ultracentrifugation, anion-exchange chromatography, hydrophobic interaction chromatography, and gel filtration. The purified enzyme gave a single protein and activity band on nondenaturing polyacrylamide gel electrophoresis and had a molecular mass of 230,000 Da. The 230-kDa enzyme was composed of large (L; 75-kDa), medium (M; 28.4-kDa), and small (S; 17.2-kDa) subunits occurring in heterohexameric (LMS)2 subunit composition. The 75-kDa polypeptide exhibited immunological cross-reactivity with the large subunit of the CODH of Oligotropha carboxidovorans. The B. japonicum enzyme contained, per mole, 2.29 atoms of Mo, 7.96 atoms of Fe, 7.60 atoms of labile S, and 1.99 mol of flavin. Treatment of the enzyme with iodoacetamide yielded di(carboxamidomethyl)molybdopterin cytosine dinucleotide, identifying molybdopterin cytosine dinucleotide as the organic portion of the B. japonicum CODH molybdenum cofactor. The absorption spectrum of the purified enzyme was characteristic of a molybdenum-containing iron-sulfur flavoprotein. PMID:10788353

  11. Carbon monoxide dehydrogenase activity in Bradyrhizobium japonicum.

    PubMed

    Lorite, M J; Tachil, J; Sanjuán, J; Meyer, O; Bedmar, E J

    2000-05-01

    Bradyrhizobium japonicum strain 110spc4 was capable of chemolithoautotrophic growth with carbon monoxide (CO) as a sole energy and carbon source under aerobic conditions. The enzyme carbon monoxide dehydrogenase (CODH; EC 1.2.99.2) has been purified 21-fold, with a yield of 16% and a specific activity of 58 nmol of CO oxidized/min/mg of protein, by a procedure that involved differential ultracentrifugation, anion-exchange chromatography, hydrophobic interaction chromatography, and gel filtration. The purified enzyme gave a single protein and activity band on nondenaturing polyacrylamide gel electrophoresis and had a molecular mass of 230,000 Da. The 230-kDa enzyme was composed of large (L; 75-kDa), medium (M; 28.4-kDa), and small (S; 17.2-kDa) subunits occurring in heterohexameric (LMS)(2) subunit composition. The 75-kDa polypeptide exhibited immunological cross-reactivity with the large subunit of the CODH of Oligotropha carboxidovorans. The B. japonicum enzyme contained, per mole, 2.29 atoms of Mo, 7.96 atoms of Fe, 7.60 atoms of labile S, and 1.99 mol of flavin. Treatment of the enzyme with iodoacetamide yielded di(carboxamidomethyl)molybdopterin cytosine dinucleotide, identifying molybdopterin cytosine dinucleotide as the organic portion of the B. japonicum CODH molybdenum cofactor. The absorption spectrum of the purified enzyme was characteristic of a molybdenum-containing iron-sulfur flavoprotein.

  12. Hierarchically structured activated carbon for ultracapacitors

    PubMed Central

    Kim, Mok-Hwa; Kim, Kwang-Bum; Park, Sun-Min; Roh, Kwang Chul

    2016-01-01

    To resolve the pore-associated bottleneck problem observed in the electrode materials used for ultracapacitors, which inhibits the transport of the electrolyte ions, we designed hierarchically structured activated carbon (HAC) by synthesizing a mesoporous silica template/carbon composite and chemically activating it to simultaneously remove the silica template and increase the pore volume. The resulting HAC had a well-designed, unique porous structure, which allowed for large interfaces for efficient electric double-layer formation. Given the unique characteristics of the HAC, we believe that the developed synthesis strategy provides important insights into the design and fabrication of hierarchical carbon nanostructures. The HAC, which had a specific surface area of 1,957 m2 g−1, exhibited an extremely high specific capacitance of 157 F g−1 (95 F cc−1), as well as a high rate capability. This indicated that it had superior energy storage capability and was thus suitable for use in advanced ultracapacitors. PMID:26878820

  13. [Caring for families of charcoal-burning suicide patients].

    PubMed

    Pien, Feng-Chen; Feng, Hsin-Pei; Tzeng, Wen-Chii

    2013-12-01

    Charcoal-burning is the second major cause of suicide death in Taiwan. Predicting the variable damage and sequelae in this suicide mode is difficult due to the rapid combination of carbon monoxide with red blood cells. Delayed neuropsychological sequelae (DNS) may result in significantly extended recovery times, causing additional stress to the family. Nurses may help increase family understanding and support and guide family members to more positive intra-family interactions, shared perspectives on the recovery process, and resource seeking behavior by depicting subsequent family life and helping the entire family develop coping strategies those allow all members to effect cognitive, emotional and behavioral change. This result may help families of attempted suicide individuals recover successfully.

  14. High-speed ultrashort pulse fiber ring laser using charcoal nanoparticles.

    PubMed

    Li, Wenbo; Hu, Hongyu; Zhang, Xiang; Zhao, Shuai; Fu, Kan; Dutta, Niloy K

    2016-03-20

    A mode-locked erbium-doped fiber ring laser that is easy to set up is proposed and experimentally demonstrated to generate a high-repetition-rate optical pulse train with an ultrashort pulse width. The laser combines a rational harmonic mode-locking technique and charcoal nanoparticles as saturable absorbers. Compared to a solely active mode-locking scheme, the scheme with charcoal nanoparticles can remove the supermodes and narrow the pulse width by a factor of 0.57 at a repetition rate of 20 GHz. Numerical simulation of the laser performance is also provided, which shows good agreement with the experimental results.

  15. Steady-state response of a charcoal bed to radon in flowing air with water vapor

    SciTech Connect

    Blue, T.E.; Jarzemba, M.S.; Fentiman, A.W.

    1995-06-01

    Previously we have developed a mathematical model of radon adsorption in active air with water vapor on small U.S. Environmental Protection Agency charcoal canisters that are used for environmental measurements of radon. The purpose of this paper is to extend this mathematical model to describe the adsorption of radon by large charcoal beds with radon-laden air flowing through them. The resulting model equations are solved analytically to predict the steady-state adsorption of radon by such beds. 14 refs., 3 figs.

  16. Activated carbon briquettes from biomass materials.

    PubMed

    Amaya, Alejandro; Medero, Natalia; Tancredi, Néstor; Silva, Hugo; Deiana, Cristina

    2007-05-01

    Disposal of biomass wastes, produced in different agricultural activities, is frequently an environmental problem. A solution for such situation is the recycling of these residues for the production of activated carbon, an adsorbent which has several applications, for instance in the elimination of contaminants. For some uses, high mechanical strength and good adsorption characteristics are required. To achieve this, carbonaceous materials are conformed as pellets or briquettes, in a process that involves mixing and pressing of char with adhesive materials prior to activation. In this work, the influence of the operation conditions on the mechanical and surface properties of briquettes was studied. Eucalyptus wood and rice husk from Uruguay were used as lignocellulosic raw materials, and concentrated grape must from Cuyo Region-Argentina, as a binder. Different wood:rice and solid:binder ratios were used to prepare briquettes in order to study their influence on mechanical and surface properties of the final products.

  17. Soil Charcoal to Assess the Impacts of Past Human Disturbances on Tropical Forests

    PubMed Central

    Vleminckx, Jason; Morin-Rivat, Julie; Biwolé, Achille B.; Daïnou, Kasso; Gillet, Jean-François; Doucet, Jean-Louis; Drouet, Thomas; Hardy, Olivier J.

    2014-01-01

    The canopy of many central African forests is dominated by light-demanding tree species that do not regenerate well under themselves. The prevalence of these species might result from ancient slash-and-burn agricultural activities that created large openings, while a decline of these activities since the colonial period could explain their deficit of regeneration. To verify this hypothesis, we compared soil charcoal abundance, used as a proxy for past slash-and-burn agriculture, and tree species composition assessed on 208 rainforest 0.2 ha plots located in three areas from Southern Cameroon. Species were classified in regeneration guilds (pioneer, non-pioneer light-demanding, shade-bearer) and characterized by their wood-specific gravity, assumed to reflect light requirement. We tested the correlation between soil charcoal abundance and: (i) the relative abundance of each guild, (ii) each species and family abundance and (iii) mean wood-specific gravity. Charcoal was found in 83% of the plots, indicating frequent past forest fires. Radiocarbon dating revealed two periods of fires: “recent” charcoal were on average 300 years old (up to 860 BP, n = 16) and occurred in the uppermost 20 cm soil layer, while “ancient” charcoal were on average 1900 years old (range: 1500 to 2800 BP, n = 43, excluding one sample dated 9400 BP), and found in all soil layers. While we expected a positive correlation between the relative abundance of light-demanding species and charcoal abundance in the upper soil layer, overall there was no evidence that the current heterogeneity in tree species composition can be explained by charcoal abundance in any soil layer. The absence of signal supporting our hypothesis might result from (i) a relatively uniform impact of past slash-and-burn activities, (ii) pedoturbation processes bringing ancient charcoal to the upper soil layer, blurring the signal of centuries-old Human disturbances, or (iii) the prevalence of other

  18. Performance enhancement with powdered activated carbon (PAC) addition in a membrane bioreactor (MBR) treating distillery effluent.

    PubMed

    Satyawali, Yamini; Balakrishnan, Malini

    2009-10-15

    This work investigated the effect of powdered activated carbon (PAC) addition on the operation of a membrane bioreactor (MBR) treating sugarcane molasses based distillery wastewater (spentwash). The 8L reactor was equipped with a submerged 30 microm nylon mesh filter with 0.05 m(2) filtration area. Detailed characterization of the commercial wood charcoal based PAC was performed before using it in the MBR. The MBR was operated over 200 days at organic loading rates (OLRs) varying from 4.2 to 6.9 kg m(-3)d(-1). PAC addition controlled the reactor foaming during start up and enhanced the critical flux by around 23%; it also prolonged the duration between filter cleaning. Operation at higher loading rates was possible and for a given OLR, the chemical oxygen demand (COD) removal was higher with PAC addition. However, biodegradation in the reactor was limited and the high molecular weight compounds were not affected by PAC supplementation. The functional groups on PAC appear to interact with the polysaccharide portion of the sludge, which may reduce its propensity to interact with the nylon mesh.

  19. Cooperative redox activation for carbon dioxide conversion

    PubMed Central

    Lian, Zhong; Nielsen, Dennis U.; Lindhardt, Anders T.; Daasbjerg, Kim; Skrydstrup, Troels

    2016-01-01

    A longstanding challenge in production chemistry is the development of catalytic methods for the transformation of carbon dioxide into useful chemicals. Silane and borane promoted reductions can be fined-tuned to provide a number of C1-building blocks under mild conditions, but these approaches are limited because of the production of stoichiometric waste compounds. Here we report on the conversion of CO2 with diaryldisilanes, which through cooperative redox activation generate carbon monoxide and a diaryldisiloxane that actively participate in a palladium-catalysed carbonylative Hiyama-Denmark coupling for the synthesis of an array of pharmaceutically relevant diarylketones. Thus the disilane reagent not only serves as the oxygen abstracting agent from CO2, but the silicon-containing ‘waste', produced through oxygen insertion into the Si–Si bond, participates as a reagent for the transmetalation step in the carbonylative coupling. Hence this concept of cooperative redox activation opens up for new avenues in the conversion of CO2. PMID:27981967

  20. Charcoal anatomy of Brazilian species. I. Anacardiaceae.

    PubMed

    Gonçalves, Thaís A P; Scheel-Ybert, Rita

    2016-01-01

    Anthracological studies are firmly advancing in the tropics during the last decades. The theoretical and methodological bases of the discipline are well established. Yet, there is a strong demand for comparative reference material, seeking for an improvement in the precision of taxonomic determination, both in palaeoecological and palaeoethnobotanical studies and to help preventing illegal charcoal production. This work presents descriptions of charcoal anatomy of eleven Anacardiaceae species from six genera native to Brazil (Anacardium occidentale, Anacardium parvifolium, Astronium graveolens, Astronium lecointei, Lithrea molleoides, Schinus terebenthifolius, Spondias mombin, Spondias purpurea, Spondias tuberosa, Tapirira guianensis, and Tapirira obtusa). They are characterized by diffuse-porous wood, vessels solitary and in multiples, tyloses and spiral thickenings sometimes present; simple perforation plates, alternate intervessel pits, rounded vessel-ray pits with much reduced borders to apparently simple; parenchyma paratracheal scanty to vasicentric; heterocellular rays, some with radial canals and crystals; septate fibres with simple pits. These results are quite similar to previous wood anatomical descriptions of the same species or genera. Yet, charcoal identification is more effective when unknown samples are compared to charred extant equivalents, instead of to wood slides.

  1. Charcoal as an airway isoflurane reflection filter.

    PubMed

    Dahm, S L; Steptoe, P; Luttropp, H H; Reinstrup, P

    1998-03-01

    The isoflurane-saving and CO2-retaining effects of a charcoal filter were compared with a Siemens standard heat and moisture (HME) exchanger and an emptied specimen (dummy). Isoflurane was delivered during the inspiratory phase and consumption investigated at 10, 15 and 25 cycles min-1. The investigation was performed by ventilation with humidified air with a constant end-tidal CO2 and temperature. For a comparison, isoflurane was delivered in a conventional manner via the ventilator. The arrangement with a charcoal filter reduced the isoflurane consumption by a factor of 2.0-2.6, depending on ventilatory rate. Most of the saving was a result of the method of isoflurane delivery (factor 1.4-2.0), while adding the reflector gave a further reduction (factor 1.3-1.5). One circumstance that reduced the net efficiency of the charcoal filter was that it also reflected CO2; consequently, total minute ventilation had to be increased to maintain constant end-tidal CO2.

  2. Adsorbed natural gas storage with activated carbon

    SciTech Connect

    Sun, Jian; Brady, T.A.; Rood, M.J.

    1996-12-31

    Despite technical advances to reduce air pollution emissions, motor vehicles still account for 30 to 70% emissions of all urban air pollutants. The Clean Air Act Amendments of 1990 require 100 cities in the United States to reduce the amount of their smog within 5 to 15 years. Hence, auto emissions, the major cause of smog, must be reduced 30 to 60% by 1998. Natural gas con be combusted with less pollutant emissions. Adsorbed natural gas (ANG) uses adsorbents and operates with a low storage pressure which results in lower capital costs and maintenance. This paper describes the production of an activated carbon adsorbent produced from an Illinois coal for ANG.

  3. Synthesis and characterization of porous, mixed phase, wrinkled, few layer graphene like nanocarbon from charcoal

    NASA Astrophysics Data System (ADS)

    Manoj, B.

    2015-12-01

    A technique to synthesis wrinkled graphene like nano carbon (GNC) from charcoal is reported in the current study. The charcoal produced by thermal decomposition and is intercalated by Hummers method. It is separated by centrifugation and sonication to get few layer graphene sheets. The structural and chemical changes of the nanostructure is elucidated by Raman spectroscopy, TEM, SEM-EDS and XPS. Raman spectra revealed the existence of highly graphitized amorphous carbon, which is confirmed by the appearance of five peaks in the deconvoluted first order Raman spectra. The SEM analysis reveals the formation of large area graphene sheets with nano-porous structure in it. The TEM/SAED analysis exhibits the presence of short range few layer graphene.

  4. Production of activated carbon from TCR char

    NASA Astrophysics Data System (ADS)

    Stenzel, Fabian; Heberlein, Markus; Klinner, Tobias; Hornung, Andreas

    2016-04-01

    The utilization of char for adsorptive purposes is known since the 18th century. At that time the char was made of wood or bones and used for decoloration of fluids. In the 20th century the production of activated carbon in an industrial scale was started. The today's raw materials for activated carbon production are hard coal, peat, wood or coconut shells. All these materials entail costs especially the latter. Thus, the utilization of carbon rich residues (biomass) is an interesting economic opportunity because it is available for no costs or even can create income. The char is produced by thermo-catalytic reforming (TCR®). This process is a combination of an intermediate pyrolysis and subsequently a reforming step. During the pyrolysis step the material is decomposed in a vapor and a solid carbon enriched phase. In the second step the vapor and the solid phase get in an intensive contact and the quality of both materials is improved via the reforming process. Subsequently, the condensables are precipitated from the vapor phase and a permanent gas as well as oil is obtained. Both are suitable for heat and power production which is a clear advantage of the TCR® process. The obtained biochar from the TCR® process has special properties. This material has a very low hydrogen and oxygen content. Its stability is comparable to hard coal or anthracite. Therefore it consists almost only of carbon and ash. The latter depends from input material. Furthermore the surface structure and area can be influenced during the reforming step. Depending from temperature and residence time the number of micro pores and the surface area can be increased. Preliminary investigations with methylene blue solution have shown that a TCR® char made of digestate from anaerobic digestion has adsorptive properties. The decoloration of the solution was achieved. A further influencing factor of the adsorption performance is the particle size. Based on the results of the preliminary tests a

  5. The addition of charcoals to broiler diets did not alter the recovery of Salmonella Typhimurium during grow-out.

    PubMed

    Wilson, K M; Bourassa, D V; Davis, A J; Freeman, M E; Buhr, R J

    2016-03-01

    Two experiments evaluated prebiotics added to feed on the recovery of Salmonella in broilers during grow-out and processing. In Experiment 1, "seeder" chicks were inoculated with Salmonella Typhimurium and placed with penmates. Treatments were: basal control diet, added 0.3% bamboo charcoal, 0.6% bamboo charcoal, or 0.12% Aromabiotic (medium chain fatty acids). The ceca from seeders and penmates were sampled to confirm Salmonella colonization at 3, 4, and 6 wk, and pen litter was sampled weekly. At 3 wk, charcoal fed chicks had significantly lower cecal recovery (37% lower) of Salmonella via direct plating but no differences at wk 4 or 6. At 6 wk, broilers fed Aromabiotic had no recovery of Salmonella from ceca with direct plating and significantly, 18%, lower recovery with enrichment. In Experiment 2, the treatments were: basal control diet, added 0.3% bamboo charcoal, 0.3% activated bamboo charcoal, or 0.3% pine charcoal. At placement, 2 seeders were challenged with Salmonella and commingled with penmates and ceca sampled at 1 and 2 wk, and ceca from 5 penmates/pen at 3 to 6 wk. Weekly, the pH of the crop and duodenum was measured from 1 penmate/pen and the litter surface sampled. At the end of grow-out broilers were processed. Results showed that penmates had colonized at 1 and 2 wk. Cecal Salmonella showed no differences except at 4 wk, when activated bamboo charcoal had a 18% lower recovery of Salmonella (enrichment) compared to the control (88%). Similar to Experiment 1, the recovery of Salmonella from the litter was not significantly different among treatments, however an overall decrease in recovery by 4 wk with direct plating reoccurred. The pH of the duodenum and the crop were not different among treatments. Crop pH (6.0) for all treatments were significantly higher at wk 1 compared to wk 2 to 6. Charcoals had minimal effect on Salmonella recovery in the ceca, but following defeathering, broilers fed charcoals had significantly lower Salmonella

  6. ENTRAINED-FLOW ADSORPTION OF MERCURY USING ACTIVATED CARBON

    EPA Science Inventory

    Bench-scale experiments were conducted in a flow reactor to simulate entrained-flow capture of elemental mercury (Hg) by activated carbon. Adsorption of Hg by several commercial activated carbons was examined at different carbon-to-mercury (C:Hg) ratios (by weight) (600:1 - 29000...

  7. Soil quality in a cropland soil treated with wood ash containing charcoal

    NASA Astrophysics Data System (ADS)

    Omil, Beatriz; Balboa, Miguel A.; Fonturbel, M. Teresa; Gartzia-Bengoetxea, Nahia; Arias-González, Ander; Vega, Jose A.; Merino, Agustin

    2014-05-01

    The strategy of the European Union "Europe 2020" states that by 2020, 20% of final energy consumption must come from renewables. In this scenario, there is an increasing use of biomass utilization for energy production. Indeed, it is expected that the production of wood-ash will increase in coming years. Wood ash, a mixture of ash and charcoal, generated as a by-product of biomass combustion in power plants, can be applied to soil to improve the soil quality and crop production. Since the residue contains significant content of charcoal, the application of mixed wood ash may also improve the SOM content and soil quality in the long term, in soils degraded as a consequence of intensive management. The objective of this study was asses the changes in SOM quality and soil properties in a degraded soils treated with wood ash containing charcoal. The study was carried out in a field devoted to cereal crops during the last decades. The soil was acidic (pH 4.5) with a low SOC content (3 %) and fine texture. The experiment was based on a randomised block design with four replicates. Each block included the following four treatments: Control, 16 Mg fly wood ash ha-1, 16 Mg mixed wood ash ha-1 (16 Mg) and 32 Mg mixed wood ash ha-1 (32 Mg). The application was carried out once. The ash used in the study was obtained from a thermal power plant and was mainly derived from the combustion of Pinus radiata bark and branches. The wood ash is highly alkaline (pH= 10), contains 10 % of highly condensed black carbon (atomic H/C ratio < 0.5 and T50 en DSC= 500 ºC). The evolution of SOM properties were monitored over three years by solid state 13C CPMAS NMR and Differential Scanning Calorimetry (DSC). These techniques were applied in bulk samples and aggregates of different sizes. The changes in microbial activity were studied by analysis of microbial biomass C and basal respiration. The soil bacterial community was studied by the Biolog method. Several physical properties, such soil

  8. Preparation of binderless activated carbon monolith from pre-carbonization rubber wood sawdust by controlling of carbonization and activation condition

    NASA Astrophysics Data System (ADS)

    Taer, E.; Deraman, M.; Taslim, R.; Iwantono

    2013-09-01

    Binderless activated carbon monolith (ACM) was prepared from pre-carbonized rubber wood sawdust (RWSD). The effect of the carbonization temperature (400, 500, 600, 700, 800 dan 900 °C) on porosity characteristic of the ACM have been studied. The optimum carbonization temperature for obtaining ACM with high surface area of 600 °C with CO2 activation at 800 °C for one hour. At this condition, the surface area as high as 733 m2 g-1 could be successfully obtained. By improved the activation temperature at 900 °C for 2.5 h, it was found that the surface area of 860 m2 g-1. For this condition, the ACM exhibit the specific capacitance of 90 F g-1. In addition the termogravimertic (TG)-differential termografimertic (DTG) and field emission scanning electron microscope (FESEM) measurement were also performed on the ACMs and the result has been studied. Finally, it was conclude that the high surface area of ACM from RWSD could be produced by proper selections of carbonization and activation condition.

  9. Plant diversity increases soil microbial activity and soil carbon storage.

    PubMed

    Lange, Markus; Eisenhauer, Nico; Sierra, Carlos A; Bessler, Holger; Engels, Christoph; Griffiths, Robert I; Mellado-Vázquez, Perla G; Malik, Ashish A; Roy, Jacques; Scheu, Stefan; Steinbeiss, Sibylle; Thomson, Bruce C; Trumbore, Susan E; Gleixner, Gerd

    2015-04-07

    Plant diversity strongly influences ecosystem functions and services, such as soil carbon storage. However, the mechanisms underlying the positive plant diversity effects on soil carbon storage are poorly understood. We explored this relationship using long-term data from a grassland biodiversity experiment (The Jena Experiment) and radiocarbon ((14)C) modelling. Here we show that higher plant diversity increases rhizosphere carbon inputs into the microbial community resulting in both increased microbial activity and carbon storage. Increases in soil carbon were related to the enhanced accumulation of recently fixed carbon in high-diversity plots, while plant diversity had less pronounced effects on the decomposition rate of existing carbon. The present study shows that elevated carbon storage at high plant diversity is a direct function of the soil microbial community, indicating that the increase in carbon storage is mainly limited by the integration of new carbon into soil and less by the decomposition of existing soil carbon.

  10. Emissions of air toxics from the production of charcoal in a simulated Missouri charcoal kiln

    SciTech Connect

    Lemieux, P.M.; Kariher, P.H.; Fairless, B.J.; Tapp, J.A.

    1998-11-01

    The paper gives results of experiments in a laboratory-scale charcoal kiln simulator to evaluate emissions of hazardous air pollutant from the production of charcoal in Missouri-type kilns. Fixed combustion gases were measured using continuous monitors. In addition, other pollutants, including methanol, volatile organic compounds, semivolatile organic compounds, and particle emission rates and size distributions were measured using various techniques. Emissions of all pollutants are reported in grams emitted per unit mass of initial wood converted to charcoal. Two burn conditions--slow and fast burn--were examined. High levels of methanol, benzene, and fine particulate were emitted from all tests. The estimated emissions from the fast burn conditions were significantly higher than those from the slow burn conditions.

  11. Preparation of activated carbons from bituminous coal pitches

    NASA Astrophysics Data System (ADS)

    Gañan, J.; González-García, C. M.; González, J. F.; Sabio, E.; Macías-García, A.; Díaz-Díez, M. A.

    2004-11-01

    High-porosity carbons were prepared from bituminous coal pitches by combining chemical and physical activation. The chemical activation process consisted of potassium hydroxide impregnation followed by carbonization in nitrogen atmosphere. The effect of the KOH impregnation ratio on the surface area and pore volumes evolution of the carbons derived from mesophase pitch was studied. The optimum KOH:pitch ratio was fixed to realize a physical activation process in order to increase the textural parameters of the KOH-activated carbons. Physical activation was performed by carbonizing the KOH-activated carbons followed by gasifying with air. The influence of the carbonization temperature and the residence time of the gasification with air were explored to optimize those preparation parameters.

  12. REPEATED REDUCTIVE AND OXIDATIVE TREATMENTS ON GRANULAR ACTIVATED CARBON

    EPA Science Inventory

    Fenton oxidation and Fenton oxidation preceded by reduction solutions were applied to granular activated carbon (GAC) to chemically regenerate the adsorbent. No adsorbate was present on the GAC so physicochemical effects from chemically aggressive regeneration of the carbon coul...

  13. Reduction of bromate by granular activated carbon

    SciTech Connect

    Kirisits, M.J.; Snoeyink, V.L.; Kruithof, J.C.

    1998-07-01

    Ozonation of waters containing bromide can lead to the formation of bromate, a probable human carcinogen. Since bromate will be regulated at 10 {micro}g/L by the Stage 1 Disinfectants/Disinfection By-Products Rule, there is considerable interest in finding a suitable method of bromate reduction. Granular activated carbon (GAC) can be used to chemically reduce bromate to bromide, but interference from organic matter and anions present in natural water render this process inefficient. In an effort to improve bromate reduction by GAC, several modifications were made to the GAC filtration process. The use of a biologically active carbon (BAC) filter ahead of a fresh GAC filter with and without preozonation, to remove the biodegradable organic matter, did not substantially improve the bromate removal of the GAC filter. The use of the BAC filter for biological bromate reduction proved to be the most encouraging experiment. By lowering the dissolved oxygen in the influent to the BAC from 8.0 mg/L to 2.0 mg/L, the percent bromate removal increased from 42% to 61%.

  14. Activated Carbon Fibers For Gas Storage

    SciTech Connect

    Burchell, Timothy D; Contescu, Cristian I; Gallego, Nidia C

    2017-01-01

    The advantages of Activated Carbon Fibers (ACF) over Granular Activated Carbon (GAC) are reviewed and their relationship to ACF structure and texture are discussed. These advantages make ACF very attractive for gas storage applications. Both adsorbed natural gas (ANG) and hydrogen gas adsorption performance are discussed. The predicted and actual structure and performance of lignin-derived ACF is reviewed. The manufacture and performance of ACF derived monolith for potential automotive natural gas (NG) storage applications is reported Future trends for ACF for gas storage are considered to be positive. The recent improvements in NG extraction coupled with the widespread availability of NG wells means a relatively inexpensive and abundant NG supply in the foreseeable future. This has rekindled interest in NG powered vehicles. The advantages and benefit of ANG compared to compressed NG offer the promise of accelerated use of ANG as a commuter vehicle fuel. It is to be hoped the current cost hurdle of ACF can be overcome opening ANG applications that take advantage of the favorable properties of ACF versus GAC. Lastly, suggestions are made regarding the direction of future work.

  15. Electrochemical activation of carbon nanotube/polymer composites.

    PubMed

    Sánchez, Samuel; Fàbregas, Esteve; Pumera, Martin

    2009-01-07

    Electrochemical activation of carbon nanotube/polysulfone composite electrodes for enhanced heterogeneous electron transfer is studied. The physicochemical insight into the electrochemical activation of carbon nanotube/polymer composites was provided by transmission electron microscopy, Raman spectroscopy, electrochemical impedance spectroscopy, and cyclic voltammetry. Dopamine, ascorbic acid, NADH, and ferricyanide are used as a model redox system for evaluating the performance of activated carbon nanotube/polymer composite electrodes. We demonstrate that polymer wrapping of carbon nanotubes is subject to defects and to partial removal during activation. Such tunable activation of electrodes would enable on-demand activation of electrodes for satisfying the needs of sensing or energy storage devices.

  16. Charcoal deposition and redeposition in Elk Lake, Minnesota, USA

    USGS Publications Warehouse

    Platt, Bradbury J.

    1996-01-01

    Sedimentary charcoal, diatom and phytolith records of the past 1500 years at Elk Lake, Minnesota, in combination with sediment trap studies and a transect of surface sediment samples, document the mechanisms by which previously deposited charcoal is redeposited and finally buried in this lake. The frequent correspondence of high diatom concentrations and peaks of phytolith and charcoal fragments suggest that currents and turbulence related to lake circulation are responsible for winnowing charcoal and phytoliths from shallow water depositional sites to deeper areas of the lake. High diatom concentrations in the record relate to increased nutrient fluxes also supplied by circulation. Despite the fact that the watershed and area around Elk Lake has not been burned since AD 1922, charcoal continues to reach the profundal zone from littoral source areas in Elk Lake. The variable redeposition of within-lake charcoal requires evaluation before fire-history records can be related to global, regional or even local fire events.

  17. DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS

    SciTech Connect

    Harold H. Schobert; M. Mercedes Maroto-Valer; Zhe Lu

    2003-09-30

    The increasing role of coal as a source of energy in the 21st century will demand environmental and cost-effective strategies for the use of coal combustion by-products (CCBPs), mainly unburned carbon in fly ash. Unburned carbon is nowadays regarded as a waste product and its fate is mainly disposal, due to the present lack of efficient routes for its utilization. However, unburned carbon is a potential precursor for the production of adsorbent carbons, since it has gone through a devolatilization process while in the combustor, and therefore, only requires to be activated. Accordingly, the principal objective of this work was to characterize and utilize the unburned carbon in fly ash for the production of activated carbons. The unburned carbon samples were collected from different combustion systems, including pulverized utility boilers, a utility cyclone, a stoker, and a fluidized bed combustor. LOI (loss-on-ignition), proximate, ultimate, and petrographic analyses were conducted, and the surface areas of the samples were characterized by N2 adsorption isotherms at 77K. The LOIs of the unburned carbon samples varied between 21.79-84.52%. The proximate analyses showed that all the samples had very low moisture contents (0.17 to 3.39 wt %), while the volatile matter contents varied between 0.45 to 24.82 wt%. The elemental analyses show that all the unburned carbon samples consist mainly of carbon with very little hydrogen, nitrogen, sulfur and oxygen In addition, the potential use of unburned carbon as precursor for activated carbon (AC) was investigated. Activated carbons with specific surface area up to 1075m{sup 2}/g were produced from the unburned carbon. The porosity of the resultant activated carbons was related to the properties of the unburned carbon feedstock and the activation conditions used. It was found that not all the unburned carbon samples are equally suited for activation, and furthermore, their potential as activated carbons precursors could be

  18. Toxicity and uptake of TRI- and dibutyltin in Daphnia magna in the absence and presence of nano-charcoal.

    PubMed

    Fang, Liping; Borggaard, Ole K; Holm, Peter E; Hansen, Hans Christian Bruun; Cedergreen, Nina

    2011-11-01

    Butyltins (BTs), such as tributyltin (TBT) and dibutyltin (DBT), are toxic to aquatic organisms, but the presence of the strong adsorbent, black carbon (BC), can markedly influence BT toxicity and uptake in organisms. In the present study, the acute toxicity and uptake of TBT and DBT in the crustacean, Daphnia magna, were investigated with and without addition of nano-charcoal at different pHs and water hardnesses. The results showed that the toxicity of TBT and DBT increased by lowering the pH from 8 to 6. This reflects a relatively higher toxicity of cationic BT species than of the neutral species. At pH 6, by enhancing the water hardness of the media from 0.6 to 2.5 mM, the toxicity of TBT and DBT consistently decreased due to competitive binding of bivalent cations (Mg²⁺, Ca²⁺) to biotic ligands of D. magna. Furthermore, the toxicity of TBT to D. magna significantly decreased in the presence of nano-charcoal compared with experiments without nano-charcoal at pH 6 and 8, while no significant decrease in toxicity of DBT was observed in the presence of nano-charcoal. This can be attributed to the insignificant decrease of free DBT concentration in the presence of nano-charcoal compared with that for TBT. Conversely, it was observed that more TBT and DBT were taken up in D. magna in the presence of nano-charcoal due to the uptake of TBT or DBT associated with nano-charcoal by Daphnia in gut systems, as seen by light microscopy. This indicated that only free nonadsorbed BTs were toxic to D. magna, at least during short periods of exposure.

  19. Superhydrophobic activated carbon-coated sponges for separation and absorption.

    PubMed

    Sun, Hanxue; Li, An; Zhu, Zhaoqi; Liang, Weidong; Zhao, Xinhong; La, Peiqing; Deng, Weiqiao

    2013-06-01

    Highly porous activated carbon with a large surface area and pore volume was synthesized by KOH activation using commercially available activated carbon as a precursor. By modification with polydimethylsiloxane (PDMS), highly porous activated carbon showed superhydrophobicity with a water contact angle of 163.6°. The changes in wettability of PDMS- treated highly porous activated carbon were attributed to the deposition of a low-surface-energy silicon coating onto activated carbon (confirmed by X-ray photoelectron spectroscopy), which had microporous characteristics (confirmed by XRD, SEM, and TEM analyses). Using an easy dip-coating method, superhydrophobic activated carbon-coated sponges were also fabricated; those exhibited excellent absorption selectivity for the removal of a wide range of organics and oils from water, and also recyclability, thus showing great potential as efficient absorbents for the large-scale removal of organic contaminants or oil spills from water.

  20. Recent Data Analysis of Carbon ACtivation

    NASA Astrophysics Data System (ADS)

    Jiang, Hui Ming; Smith, Elizabeth; Padalino, Stephen; Baumgart, Leigh; Suny Geneseooltz, Katie; Colburn, Robyn; Fuschino, Julia

    2002-10-01

    A method for measuring tertiary neutrons produced in Inertial Confinement Fusion reactions has been developed using carbon activation. Ultra pure samples of carbon, free from positron-emitting contaminants must be used in the detection. Our primary goal has been to reduce the contamination level by refining purification and packaging procedures. This process involves baking the disks in a vacuum oven to 1000¢XC @ 200 microns for a prescribed bake time without exposing the disks to nitrogen in the air which is a major contaminant. Recent experiments were conducted to determine the optimal bake time for purification. Disks were baked for varying times, from one hour to five hours, and then exposed to high-neutron-yield ( 5 x 1013) shots on OMEGA. Data collected was normalized to the same time interval and the same primary neutron yield, and no significant difference in the number of background counts was seen. Experimental results also indicated that disks that were exposed to air for short time intervals showed a significant increase in the number of contamination counts. This further supports our findings that the gaseous diffusion through graphite disks is very high. Experimental results of these findings will be presented. Research funded in part by the United States Department of Energy.

  1. Activated Carbon Composites for Air Separation

    SciTech Connect

    Baker, Frederick S; Contescu, Cristian I; Tsouris, Costas; Burchell, Timothy D

    2011-09-01

    Coal-derived synthesis gas is a potential major source of hydrogen for fuel cells. Oxygen-blown coal gasification is an efficient approach to achieving the goal of producing hydrogen from coal, but a cost-effective means of enriching O2 concentration in air is required. A key objective of this project is to assess the utility of a system that exploits porous carbon materials and electrical swing adsorption to produce an O2-enriched air stream for coal gasification. As a complement to O2 and N2 adsorption measurements, CO2 was used as a more sensitive probe molecule for the characterization of molecular sieving effects. To further enhance the potential of activated carbon composite materials for air separation, work was implemented on incorporating a novel twist into the system; namely the addition of a magnetic field to influence O2 adsorption, which is accompanied by a transition between the paramagnetic and diamagnetic states. The preliminary findings in this respect are discussed.

  2. Influences of charcoal and bamboo charcoal amendment on soil-fluoride fractions and bioaccumulation of fluoride in tea plants.

    PubMed

    Gao, Hongjian; Zhang, Zhengzhu; Wan, Xiaochun

    2012-10-01

    High levels of fluoride in tea plants pose a potential health risk to humans who drink tea. It has been demonstrated that tea plant fluoride is closely related to the available fluoride in soil. But approaches that could be used to regulate the availability of fluoride in soil have been rarely seen. This study aims to investigate how the addition of charcoal and bamboo charcoal affected soil fluoride availability and bioaccumulation of fluoride in tea plants. In a microcosm experiment, tea plants were grown in the tea garden soil mixed with different amounts of charcoal and bamboo charcoal [that is, 0.5, 1.0, 2.5, and 5.0 % (w/w)]. Soil-fluoride fractions and fluoride accumulated in tea plants were determined using the sequential extraction and ion selective electrode method. Obtained results showed that both charcoal and bamboo charcoal additions significantly enhanced the concentrations of Fe/Mn oxide-bound fluoride, but significantly reduced the concentrations of water-soluble and exchangeable fluoride (p < 0.05) in soil. Charcoal and bamboo charcoal additions also significantly decreased the amounts of fluoride in tea roots and tea leaves (p < 0.05). However, the additions of charcoal and bamboo charcoal had no impacts on the tea quality, as indexed by the concentrations of polysaccharides, polyphenols, amino acids, and caffeine in tea leaves. These results suggested that application of charcoal and bamboo charcoal may provide a useful method to reduce the availability of fluoride in soil and the subsequent fluoride uptake by tea plants.

  3. Highly porous activated carbons prepared from carbon rich Mongolian anthracite by direct NaOH activation

    NASA Astrophysics Data System (ADS)

    Byamba-Ochir, Narandalai; Shim, Wang Geun; Balathanigaimani, M. S.; Moon, Hee

    2016-08-01

    Highly porous activated carbons (ACs) were prepared from Mongolian raw anthracite (MRA) using sodium hydroxide as an activation agent by varying the mass ratio (powdered MRA/NaOH) as well as the mixing method of chemical agent and powdered MRA. The specific BET surface area and total pore volume of the prepared MRA-based activated carbons (MACs) are in the range of 816-2063 m2/g and of 0.55-1.61 cm3/g, respectively. The pore size distribution of MACs show that most of the pores are in the range from large micropores to small mesopores and their distribution can be controlled by the mass ratio and mixing method of the activating agent. As expected from the intrinsic property of the MRA, the highly graphitic surface morphology of prepared carbons was confirmed from Raman spectra and transmission electron microscopy (TEM) studies. Furthermore the FTIR and XPS results reveal that the preparation of MACs with hydrophobic in nature is highly possible by controlling the mixing conditions of activating agent and powdered MRA. Based on all the results, it is suggested that the prepared MACs could be used for many specific applications, requiring high surface area, optimal pore size distribution, proper surface hydrophobicity as well as strong physical strength.

  4. Reuse performance of granular-activated carbon and activated carbon fiber in catalyzed peroxymonosulfate oxidation.

    PubMed

    Yang, Shiying; Li, Lei; Xiao, Tuo; Zhang, Jun; Shao, Xueting

    2017-03-01

    Recently, activated carbon was investigated as an efficient heterogeneous metal-free catalyst to directly activate peroxymonosulfate (PMS) for degradation of organic compounds. In this paper, the reuse performance and the possible deactivation reasons of granular-activated carbon (GAC) and activated carbon fiber (ACF) in PMS activation were investigated. As results indicated, the reusability of GAC, especially in the presence of high PMS dosage, was relatively superior to ACF in catalyzed PMS oxidation of Acid Orange 7 (AO7), which is much more easily adsorbed by ACF than by GAC. Pre-oxidation experiments were studied and it was demonstrated that PMS oxidation on ACF would retard ACF's deactivation to a big extent. After pre-adsorption with AO7, the catalytic ability of both GAC and ACF evidently diminished. However, when methanol was employed to extract the AO7-spent ACF, the catalytic ability could recover quite a bit. GAC and ACF could also effectively catalyze PMS to degrade Reactive Black 5 (RB5), which is very difficult to be adsorbed even by ACF, but both GAC and ACF have poor reuse performance for RB5 degradation. The original organic compounds or intermediate products adsorbed by GAC or ACF would be possibly responsible for the deactivation.

  5. Enhanced adsorption of humic acids on ordered mesoporous carbon compared with microporous activated carbon.

    PubMed

    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.

  6. Characterization of Activated Carbons from Oil-Palm Shell by CO2 Activation with No Holding Carbonization Temperature

    PubMed Central

    Herawan, S. G.; Hadi, M. S.; Ayob, Md. R.; Putra, A.

    2013-01-01

    Activated carbons can be produced from different precursors, including coals of different ranks, and lignocellulosic materials, by physical or chemical activation processes. The objective of this paper is to characterize oil-palm shells, as a biomass byproduct from palm-oil mills which were converted into activated carbons by nitrogen pyrolysis followed by CO2 activation. The effects of no holding peak pyrolysis temperature on the physical characteristics of the activated carbons are studied. The BET surface area of the activated carbon is investigated using N2 adsorption at 77 K with selected temperatures of 500, 600, and 700°C. These pyrolysis conditions for preparing the activated carbons are found to yield higher BET surface area at a pyrolysis temperature of 700°C compared to selected commercial activated carbon. The activated carbons thus result in well-developed porosities and predominantly microporosities. By using this activation method, significant improvement can be obtained in the surface characteristics of the activated carbons. Thus this study shows that the preparation time can be shortened while better results of activated carbon can be produced. PMID:23737721

  7. Characterization of activated carbons from oil-palm shell by CO2 activation with no holding carbonization temperature.

    PubMed

    Herawan, S G; Hadi, M S; Ayob, Md R; Putra, A

    2013-01-01

    Activated carbons can be produced from different precursors, including coals of different ranks, and lignocellulosic materials, by physical or chemical activation processes. The objective of this paper is to characterize oil-palm shells, as a biomass byproduct from palm-oil mills which were converted into activated carbons by nitrogen pyrolysis followed by CO2 activation. The effects of no holding peak pyrolysis temperature on the physical characteristics of the activated carbons are studied. The BET surface area of the activated carbon is investigated using N2 adsorption at 77 K with selected temperatures of 500, 600, and 700°C. These pyrolysis conditions for preparing the activated carbons are found to yield higher BET surface area at a pyrolysis temperature of 700°C compared to selected commercial activated carbon. The activated carbons thus result in well-developed porosities and predominantly microporosities. By using this activation method, significant improvement can be obtained in the surface characteristics of the activated carbons. Thus this study shows that the preparation time can be shortened while better results of activated carbon can be produced.

  8. Charcoal as an alternative energy source. sub-project: briquetting of charcoal

    SciTech Connect

    Enstad, G.G.

    1982-02-02

    Charcoal briquettes have been studied both theoretically and experimentally. It appears most realistic to use binders in solution. Binders of this kind have been examined and the briquettes' mechanical properties measured. Most promising are borresperse, gum arabic, dynolex, and wood tar.

  9. Toward a "molecular thermometer" to estimate the charring temperature of wildland charcoals derived from different biomass sources.

    PubMed

    Schneider, Maximilian P W; Pyle, Lacey A; Clark, Kenneth L; Hockaday, William C; Masiello, Caroline A; Schmidt, Michael W I

    2013-10-15

    The maximum temperature experienced by biomass during combustion has a strong effect on chemical properties of the resulting charcoal, such as sorption capacity (water and nonpolar materials) and microbial degradability. However, information about the formation temperature of natural charcoal can be difficult to obtain in ecosystems that are not instrumented prior to fires. Benzene polycarboxylic acids (BPCA) are molecular markers specific for pyrogenic carbon (PyC) which can provide information on the degree of aromatic condensation in charcoals. Here we apply the BPCA molecular marker method to a set of 10 charcoals produced during an experimental fire in a Pitch pine-scrub oak forest from litter and bark of pitch pine and inkberry plants in the Pinelands National Reserve in New Jersey, USA. We deployed temperature-sensitive crayons throughout the burn site, which recorded the maximum air temperature and made comparisons to the degree of thermal alteration recorded by BPCA molecular markers. Our results show an increase of the degree of aromatic condensation with monitored temperatures for bark biomass, while for needles no clear trend could be observed. For leaf-derived charcoals at increasing monitored fire temperatures, decreasing degree of aromatic condensation was obtained. This suggests that molecular markers can be used to roughly estimate the maximum fire temperatures experienced by bark and wood materials, but not based on leaf- and needle-derived materials. Possible applications include verifying declared pyrolysis temperatures of biochars and evaluating ecosystem fire temperature postburn.

  10. Structural characterization of charcoal size-fractions from a burnt Pinus pinea forest by FT-IR, Raman and surface-enhanced Raman spectroscopies

    NASA Astrophysics Data System (ADS)

    Francioso, Ornella; Sanchez-Cortes, Santiago; Bonora, Sergio; Roldán, Maria Lorena; Certini, Giacomo

    2011-05-01

    Charcoal is mainly composed by aromatic C but is characterized by several degrees of aromaticity, which complicate its identification and quantification in natural environments by conventional analyses. Charcoal is an almost ubiquitous component of soil, although often occurring in minor amounts. Hence, there is a great interest in studying the charcoal structure and understanding the behavior of charcoal in soils. In soil, it has been demonstrated that the chemical structure of charcoal is also dependant on its particle-size. In this paper we have applied infrared, normal Raman, SERS and SEF spectroscopies to study four size-fractions of charcoal (>2 mm, 2-1 mm, 1-0.5 mm and <0.5 mm) and their alkaline extracts from a burnt Pinus pinea forest. Second derivative FT-IR in agreement with the normal Raman spectroscopy have given information about the size of aromatic rings and the nature of substituted groups in size-fractions of charcoal. Carbon cluster size progressively decreased in the smallest fractions suggesting that higher graphitization and crystallization occurred in the coarsest fraction (>2 mm). The presence of organic N was well evidenced by the vibration of iso-cyanate and cyanamide groups in the fractions. This result is of great environmental importance because N may be immobilized in form of stable molecules like N-heterocyclic poliaromatic structures, and so persists in soils. The soluble organic C (SOC) extracted from charcoal size-fractions did not differ from the bulk charcoal in terms of IR and Raman spectra. Instead SERS and SEF provided further information regarding the ratio between the aromatic component and the aliphatic cross-linking one in studied fractions.

  11. [Effects of different fertilizer application on soil active organic carbon].

    PubMed

    Zhang, Rui; Zhang, Gui-Long; Ji, Yan-Yan; Li, Gang; Chang, Hong; Yang, Dian-Lin

    2013-01-01

    The variation characteristics of the content and components of soil active organic carbon under different fertilizer application were investigated in samples of calcareous fluvo-aquic soil from a field experiment growing winter wheat and summer maize in rotation in the North China Plain. The results showed that RF (recommended fertilization), CF (conventional fertilization) and NPK (mineral fertilizer alone) significantly increased the content of soil dissolved organic carbon and easily oxidized organic carbon by 24.92-38.63 mg x kg(-1) and 0.94-0.58 mg x kg(-1) respectively compared to CK (unfertilized control). The soil dissolved organic carbon content under OM (organic manure) increased greater than those under NPK and single fertilization, soil easily oxidized organic carbon content under OM and NPK increased greater than that under single chemical fertilization. OM and NPK showed no significant role in promoting the soil microbial biomass carbon, but combined application of OM and NPK significantly increased the soil microbial biomass carbon content by 36.06% and 20.69%, respectively. Soil easily oxidized organic carbon, dissolved organic carbon and microbial biomass carbon accounted for 8.41% - 14.83%, 0.47% - 0.70% and 0.89% - 1.20% of the total organic carbon (TOC), respectively. According to the results, the fertilizer application significantly increased the proportion of soil dissolved organic carbon and easily oxidized organic carbon, but there was no significant difference in the increasing extent of dissolved organic carbon. The RF and CF increased the proportion of soil easily oxidized organic carbon greater than OM or NPK, and significantly increased the proportion of microbial biomass carbon. OM or RF had no significant effect on the proportion of microbial biomass carbon. Therefore, in the field experiment, appropriate application of organic manure and chemical fertilizers played an important role for the increase of soil active organic carbon

  12. Superfund record of decision amendment (EPA Region 4): Wrigley Charcoal Superfund Site, Hickman County, Wrigley, TN, February 2, 1995

    SciTech Connect

    1995-03-01

    This decision document presents the selected Interim Remedial Action (IRA) for the Wrigley Charcoal Site, in Wrigley, Hickman County, Tennessee. The U.S. EPA has modified a wide variety of items that require immediate response action for the first step of cleanup activities to be taken at the Wrigley Charcoal Site. The major goal of these cleanup activities is to address the most serious threats at the Wrigley Charcoal Site by removing contaminated media from the Primary Site flood plain, remediating wastes at the Storage Basin, and through limited access restrictions at the Primary Site and the Storage Basin. The cleanup activities as presented in this IRA Record of Decision (ROD) Amendment will achieve significant risk reduction and will prepare the Site for future remedial activities.

  13. Charcoal tattoo localization for differentiated thyroid cancer recurrence in the central compartment of the neck.

    PubMed

    Soprani, F; Bondi, F; Puccetti, M; Armaroli, V

    2012-04-01

    Recurrence of differentiated thyroid cancer can often require further surgical options. Reoperations may carry significant risk of surgical complications; additionally, as the anatomy is subverted, there is the possibility of leaving residual neoplasm. In order to avoid such problems during reoperation for differentiated thyroid cancer recurrence, we have introduced the technique of preoperative ultrasound-guided tattooing localization of the lymphatic structure to be removed with a 4% solution of active charcoal. Using ultrasound guidance, the lesion is identified and 0.5-2 ml of colloidal charcoal is injected near the lesion. The extraction of the needle is accompanied by injection at constant pressure of other charcoal as to leave a trace of colouring along the path of the needle up to the skin. The preoperative injection was well tolerated in all cases. In the last 5 years, we have used this technique in 13 patients with suspected recurrence in the central compartment (all from papillary carcinomas). Postoperative ultrasound and histological examination confirmed the removal of the lesion in all patients; in one case, the lesion was a parathyroid cyst. Complications were observed in two of 13 (15.4%) cases (one transitory hypoparathyroidism, and one transitory vocal cord paresis). Considering our experience, charcoal tattoo localization can be considered a safe, low-cost technique that is extremely useful for facilitating surgical procedures, and reduces the risk of iatrogenic damage.

  14. Effect of Catnip Charcoal on the In Vivo Pharmacokinetics of the Main Alkaloids of Rhizoma Coptidis

    PubMed Central

    He, Yanfei; Chen, Siyu; Yu, Hai; Zhu, Long; Liu, Yayun; Han, Chunyang; Liu, Cuiyan

    2016-01-01

    This study aims to explore the effect of catnip Nepeta cataria (CNC) charcoal on the pharmacokinetics of the main alkaloids of Rhizoma Coptidis in vivo. Twenty-four rabbits were randomly divided into four groups and given oral administration of an aqueous extract of Rhizoma Coptidis (RCAE), RCAE plus CNC, RCAE plus activated carbon (AC), or distilled water, respectively. Plasma samples were collected after administration. The concentrations of berberine, coptisine, palmatine, and epiberberine in plasma were measured by high-performance liquid chromatography (HPLC). The pharmacokinetics data were calculated using pharmacokinetic DAS 2.0 software. The results showed that the area under the concentration-time curve (AUC) of berberine increased, while the AUC of coptisine, palmatine, and epiberberine decreased in the rabbits that received RCAE plus CNC. Meanwhile, the AUC of berberine, coptisine, palmatine, and epiberberine decreased in the group given RCAE plus AC. The difference of main pharmacokinetics parameters among the four groups was significant (P < 0.05). This study showed that CNC improved the bioavailability of berberine in comparison to AC and prolonged its release in comparison to RCAE alone. However, it decreased the bioavailability of coptisine, palmatine, and epiberberine. In comparison, AC uniformly declined the bioavailability of berberine, coptisine, palmatine, and epiberberine. PMID:27313645

  15. Effect of Catnip Charcoal on the In Vivo Pharmacokinetics of the Main Alkaloids of Rhizoma Coptidis.

    PubMed

    He, Yanfei; Chen, Siyu; Yu, Hai; Zhu, Long; Liu, Yayun; Han, Chunyang; Liu, Cuiyan

    2016-01-01

    This study aims to explore the effect of catnip Nepeta cataria (CNC) charcoal on the pharmacokinetics of the main alkaloids of Rhizoma Coptidis in vivo. Twenty-four rabbits were randomly divided into four groups and given oral administration of an aqueous extract of Rhizoma Coptidis (RCAE), RCAE plus CNC, RCAE plus activated carbon (AC), or distilled water, respectively. Plasma samples were collected after administration. The concentrations of berberine, coptisine, palmatine, and epiberberine in plasma were measured by high-performance liquid chromatography (HPLC). The pharmacokinetics data were calculated using pharmacokinetic DAS 2.0 software. The results showed that the area under the concentration-time curve (AUC) of berberine increased, while the AUC of coptisine, palmatine, and epiberberine decreased in the rabbits that received RCAE plus CNC. Meanwhile, the AUC of berberine, coptisine, palmatine, and epiberberine decreased in the group given RCAE plus AC. The difference of main pharmacokinetics parameters among the four groups was significant (P < 0.05). This study showed that CNC improved the bioavailability of berberine in comparison to AC and prolonged its release in comparison to RCAE alone. However, it decreased the bioavailability of coptisine, palmatine, and epiberberine. In comparison, AC uniformly declined the bioavailability of berberine, coptisine, palmatine, and epiberberine.

  16. Adsorption of aromatic compounds by carbonaceous adsorbents: a comparative study on granular activated carbon, activated carbon fiber, and carbon nanotubes.

    PubMed

    Zhang, Shujuan; Shao, Ting; Kose, H Selcen; Karanfil, Tanju

    2010-08-15

    Adsorption of three aromatic organic compounds (AOCs) by four types of carbonaceous adsorbents [a granular activated carbon (HD4000), an activated carbon fiber (ACF10), two single-walled carbon nanotubes (SWNT, SWNT-HT), and a multiwalled carbon nanotube (MWNT)] with different structural characteristics but similar surface polarities was examined in aqueous solutions. Isotherm results demonstrated the importance of molecular sieving and micropore effects in the adsorption of AOCs by carbonaceous porous adsorbents. In the absence of the molecular sieving effect, a linear relationship was found between the adsorption capacities of AOCs and the surface areas of adsorbents, independent of the type of adsorbent. On the other hand, the pore volume occupancies of the adsorbents followed the order of ACF10 > HD4000 > SWNT > MWNT, indicating that the availability of adsorption site was related to the pore size distributions of the adsorbents. ACF10 and HD4000 with higher microporous volumes exhibited higher adsorption affinities to low molecular weight AOCs than SWNT and MWNT with higher mesopore and macropore volumes. Due to their larger pore sizes, SWNTs and MWNTs are expected to be more efficient in adsorption of large size molecules. Removal of surface oxygen-containing functional groups from the SWNT enhanced adsorption of AOCs.

  17. Evaluation of soybean genotypes for resistance to charcoal rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Charcoal rot caused by Macrophomina phaseolina causes more yield loss in soybean than most other diseases in the southern U.S.A. There are no commercial genotypes marketed as resistant to charcoal rot of soybean. Reactions of 27 maturity group (MG) III, 29 Early MG IV, 34 Late MG IV, and 59 MG V gen...

  18. Characterization of charcoals for helium cryopumping in fusion devices

    SciTech Connect

    Sedgley, D.W.; Tobin, A.G.; Batzer, T.H.; Call, W.R.

    1987-07-01

    The capability of charcoal as a sorbent for helium at cryogenic temperatures depends upon charcoal characteristics that are not well understood. Previous work by the authors has indicated that the charcoals' pumping capability for helium depends as much on their source as on their particle size distributions. To develop a correlation between the physical characteristics of charcoal and helium pumping performance, different charcoals based on wood, coal, coconut, and a petroleum by-product were obtained from commercial sources. They were bonded to an aluminum substrate, and cooled to liquid-helium temperatures in a vacuum chamber. The helium pumping speed at constant throughput versus quantity of helium absorbed was measured for each charcoal grade. Porosimetry measurements on each charcoal grade using nitrogen as the sorbent gas were made that included total surface area, adsorption and desorption isotherms, and pore area and pore volume distributions. Significant differences in helium pumping performance and in pore size distribution were observed. Comparisons are made between helium pumping performance and charcoal characteristics and a possible correlation is identified.

  19. Resistance to charcoal rot identified in ancestral soybean germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Charcoal rot, caused by the fungal pathogen Macrophomina phaseolina, is an economically important disease on soybean and other crops including maize, sorghum, and sunflowers. Without effective cultural or chemical options to control charcoal rot in soybean, finding sources of genetic resistance is o...

  20. Comparative radiocarbon dating of lignite, pottery, and charcoal samples from Babeldaob Island, Republic of Palau

    SciTech Connect

    Anderson, A.; Chappell, J.; Clark, G.; Phear, S.

    2005-07-01

    It is difficult to construct archaeological chronologies for Babeldaob, the main island of Palau (western Micronesia), because the saprolitic clays of the dominant terraced-hill sites and associated ceramic sherds often contain old carbon that originated in lignites. This has implications, as well, for chronologies of sedimentary sequences. Comparative analysis of the dating problem using lignite, pottery, and charcoal samples indicates that, in fact, there are both old and young sources of potential contamination. It is concluded that radiocarbon samples from Babeldaob need to be tested for appropriate carbon content rather than relying solely upon material identification.

  1. JPL Activated Carbon Treatment System (ACTS) for sewage

    NASA Technical Reports Server (NTRS)

    1976-01-01

    An Activated Carbon Treatment System (ACTS) was developed for sewage treatment and is being applied to a one-million gallon per day sewage treatment pilot plant in Orange County California. Activities reported include pyrolysis and activation of carbon-sewage sludge, and activated carbon treatment of sewage to meet ocean discharge standards. The ACTS Sewage treatment operations include carbon-sewage treatment, primary and secondary clarifiers, gravity (multi-media) filter, filter press dewatering, flash drying of carbon-sewage filter cake, and sludge pyrolysis and activation. Tests were conducted on a laboratory scale, 10,000 gallon per day demonstration plant and pilot test equipment. Preliminary economic studies are favorable to the ACTS process relative to activated sludge treatment for a 175,000,000 gallon per day sewage treatment plant.

  2. Activated Carbon Modified with Copper for Adsorption of Propanethiol

    PubMed Central

    Moreno-Piraján, Juan Carlos; Tirano, Joaquín; Salamanca, Brisa; Giraldo, Liliana

    2010-01-01

    Activated carbons were characterized texturally and chemically before and after treatment, using surface area determination in the BET model, Boehm titration, TPR, DRX and immersion calorimetry. The adsorption capacity and the kinetics of sulphur compound removal were determined by gas chromatography. It was established that the propanethiol retention capacity is dependent on the number of oxygenated groups generated on the activated carbon surface and that activated carbon modified with CuO at 0.25 M shows the highest retention of propanethiol. Additionally is proposed a mechanism of decomposition of propenothiol with carbon-copper system. PMID:20479992

  3. Influence of charcoal burning induced pyrolysis on soils

    NASA Astrophysics Data System (ADS)

    Hirsch, Florian; Nicolay, Alexander; Pötzsch, Bastian; Fritzsche, Marie; Raab, Alexandra; Raab, Thomas

    2014-05-01

    In Lusatia, Northeastern Germany, the production of ironware between the 16th and 19th century left behind a remarkable amount of charcoal kilns in the forests north of Cottbus. Remote sensing surveys, underpinned by archaeological studies, show that charcoal was gained around Cottbus from several thousand charcoal kilns which had internal diameters up to 20 m. For the study site with 35 km2 area, the until now prospected total ground area below the charcoal kilns which was potentially affected by the pyrolysis is about 0,5 km2. Historic data indicates that the pyrolysis in the charcoal kiln took up to several weeks, for the kilns with a diameter of 20 m about 20 days. To characterize the depth of thermal alteration of soils below the kiln our current focus is on the differentiation of the iron hydroxides by small-scale vertical analysis of soil profiles. The study site is situated 16 km northeast of Cottbus at the opencast mine Jänschwalde. Field work was done during the archaeological rescue excavation of a charcoal kiln in a 50 m long trench crossing an about 15 m wide charcoal kiln. One vertical profile outside the charcoal kiln and two vertical profiles below the charcoal kiln were chosen for analysis. The magnetic susceptibility was measured in situ on the undisturbed profile and ex situ on stepwise heated samples (105, 350, 550, 750 and 950°C). The total iron content was quantified ex situ by x-ray fluorescence. Our first results indicate a change in the magnetic susceptibility in the contact area of the mineral soil and the charcoal kiln. The influence of the pyrolysis on the soil is restricted to areas where the soil was not shielded against the heat by ash or organic material.

  4. Preparation of nitrogen-enriched activated carbons from brown coal

    SciTech Connect

    Robert Pietrzak; Helena Wachowska; Piotr Nowicki

    2006-05-15

    Nitrogen-enriched activated carbons were prepared from a Polish brown coal. Nitrogen was introduced from urea at 350{sup o}C in an oxidizing atmosphere both to carbonizates obtained at 500-700{sup o}C and to activated carbons prepared from them. The activation was performed at 800{sup o}C with KOH in argon. It has been observed that the carbonization temperature determines the amount of nitrogen that is incorporated (DC5U, 8.4 wt % N{sup daf}; DC6U, 6.3 wt % N{sup daf}; and DC7U, 5.4 wt % N{sup daf}). X-ray photoelectron spectroscopy (XPS) measurements have shown that nitrogen introduced both at the stage of carbonizates and at the stage of activated carbons occurs mainly as -6, -5, and imine, amine and amide groups. On the other hand, the activation of carbons enriched with nitrogen results in the formation of pyridonic nitrogen and N-Q. The introduction of nitrogen at the activated carbon stage leads to a slight decrease in surface area. It has been proven that the most effective way of preparing microporous activated carbons enriched with nitrogen to a considerable extent and having high surface area ({approximately} 3000 m{sup 2}/g) is the following: carbonization - activation - reaction with urea. 40 refs., 1 fig., 6 tabs.

  5. Former charcoal kiln sites where forest was cleared for cultivation: a case study of old biochar in cropland

    NASA Astrophysics Data System (ADS)

    Hardy, Brieuc; Dufey, Joseph E.; Cornelis, Jean-Thomas

    2014-05-01

    The use of biochar as a soil amendment is being increasingly investigated as a win-win solution for mitigating the anthropic CO2 emissions and improving soil fertility. However, data on the long term impact of chars on soil properties are scarce, although they are crucial for better understanding the implications of large scale application of highly persistent biochars to soil. In Wallonia (Belgium), old charcoal kilns are found in most of the area that was forested in the late 18th century. Since then, a non-negligible part of the forest has been cleared for cultivation. Today, old charcoal-making platforms can be seen on bare soils as circular or elliptic black spots due to charcoal enrichment. In order to assess the long-term (>200 years) effects of biochar on soil chemical properties, seventeen kiln sites were chosen in several cropland areas of Wallonia on loessic luvisols (14) and loamy cambisols (3). Composite samples were taken in the ploughing layer (0 - 25 cm) and the underlying horizon (35 - 50 cm) in and out the kiln sites. The pH, total carbon (C) and nitrogen (N) contents, oxidizable carbon (CW&B), available phosphorus (Pav), cation exchange capacity at pH 7 (CEC), exchangeable cations content (Ca++, Mg++, K+, Na+) and loss on ignition at 550°C (LI550) were measured. In order to assess the impact of cultivation on charcoal aging, we also sampled four kiln sites on loessic luvisols under forest. Here, we show that charcoal, diluted laterally by successive tillage, acts as a carbon surplus in the topsoil layer of the black spots. The charcoal-enriched horizon is characterized by higher CEC, C/N and C/LI550 ratio compared to the reference soil. Cultivation of former forest soils accelerates charcoal aging, likely due to a combined effect of mechanical (tillage splits charcoal fragments in smaller pieces and increases soil aeration) and biological actions (promoted by improved trophic conditions due to application of amendments and fertilizers over many

  6. Microbial Enzyme Activity and Carbon Cycling in Grassland Soil Fractions

    NASA Astrophysics Data System (ADS)

    Allison, S. D.; Jastrow, J. D.

    2004-12-01

    Extracellular enzymes are necessary to degrade complex organic compounds present in soils. Using physical fractionation procedures, we tested whether old soil carbon is spatially isolated from degradative enzymes across a prairie restoration chronosequence in Illinois, USA. We found that carbon-degrading enzymes were abundant in all soil fractions, including macroaggregates, microaggregates, and the clay fraction, which contains carbon with a mean residence time of ~200 years. The activities of two cellulose-degrading enzymes and a chitin-degrading enzyme were 2-10 times greater in organic matter fractions than in bulk soil, consistent with the rapid turnover of these fractions. Polyphenol oxidase activity was 3 times greater in the clay fraction than in the bulk soil, despite very slow carbon turnover in this fraction. Changes in enzyme activity across the restoration chronosequence were small once adjusted for increases in soil carbon concentration, although polyphenol oxidase activity per unit carbon declined by 50% in native prairie versus cultivated soil. These results are consistent with a `two-pool' model of enzyme and carbon turnover in grassland soils. In light organic matter fractions, enzyme production and carbon turnover both occur rapidly. However, in mineral-dominated fractions, both enzymes and their carbon substrates are immobilized on mineral surfaces, leading to slow turnover. Soil carbon accumulation in the clay fraction and across the prairie restoration chronosequence probably reflects increasing physical isolation of enzymes and substrates on the molecular scale, rather than the micron to millimeter scale.

  7. A Magnesium-Activated Carbon Hybrid Capacitor

    SciTech Connect

    Yoo, HD; Shterenberg, I; Gofer, Y; Doe, RE; Fischer, CC; Ceder, G; Aurbach, D

    2013-12-11

    Prototype cells of hybrid capacitor were developed, comprising activated carbon (AC) cloth and magnesium (Mg) foil as the positive and negative electrodes, respectively. The electrolyte solution included ether solvent (TBF) and a magnesium organo-halo-aluminate complex 0.25 M Mg2Cl3+-Ph2AlCl2-. In this solution Mg can be deposited/dissolved reversibly for thousands of cycles with high reversibility (100% cycling efficiency). The main barrier for integrating porous AC electrodes with this electrolyte solution was the saturation of the pores with the large ions in the AC prior to reaching the potential limit. This is due to the existence of bulky Mg and Al based ionic complexes consisting Cl, alkyl or aryl (R), and THF ligands. This problem was resolved by adding 0.5 M of lithium chloride (LiCl), thus introducing smaller ionic species to the solution. This Mg hybrid capacitor system demonstrated a stable cycle performance for many thousands of cycles with a specific capacitance of 90 Fg(-1) for the AC positive electrodes along a potential range of 2.4 V. (C) 2014 The Electrochemical Society. All rights reserved.

  8. Adsorption of EDTA on activated carbon from aqueous solutions.

    PubMed

    Zhu, Hai-song; Yang, Xiao-juan; Mao, Yan-peng; Chen, Yu; Long, Xiang-li; Yuan, Wei-kang

    2011-01-30

    In this study, the adsorption of EDTA on activated carbon from aqueous solutions has been investigated in a batch stirred cell. Experiments have been carried out to investigate the effects of temperature, EDTA concentration, pH, activated carbon mass and particle size on EDTA adsorption. The experimental results manifest that the EDTA adsorption rate increases with its concentration in the aqueous solutions. EDTA adsorption also increases with temperature. The EDTA removal from the solution increases as activated carbon mass increases. The Langmuir and Freundlich equilibrium isotherm models are found to provide a good fitting of the adsorption data, with R(2) = 0.9920 and 0.9982, respectively. The kinetic study shows that EDTA adsorption on the activated carbon is in good compliance with the pseudo-second-order kinetic model. The thermodynamic parameters (E(a), ΔG(0), ΔH(0), ΔS(0)) obtained indicate the endothermic nature of EDTA adsorption on activated carbon.

  9. Ozone Removal by Filters Containing Activated Carbon: A Pilot Study

    SciTech Connect

    Fisk, William; Spears, Mike; Sullivan, Douglas; Mendell, Mark

    2009-09-01

    This study evaluated the ozone removal performance of moderate-cost particle filters containing activated carbon when installed in a commercial building heating, ventilating, and air conditioning (HVAC) system. Filters containing 300 g of activated carbon per 0.09 m2 of filter face area were installed in two 'experimental' filter banks within an office building located in Sacramento, CA. The ozone removal performance of the filters was assessed through periodic measurements of ozone concentrations in the air upstream and downstream of the filters. Ozone concentrations were also measured upstream and downstream of a 'reference' filter bank containing filters without any activated carbon. The filter banks with prefilters containing activated carbon were removing 60percent to 70percent of the ozone 67 and 81 days after filter installation. In contrast, there was negligible ozone removal by the reference filter bank without activated carbon.

  10. The adsorption of sympathomimetic agents by activated carbon hemoperfusion.

    PubMed

    Horres, C R; Hill, J B; Ellis, F W

    1976-01-01

    Sympathomimetic agents with mixed and pure alpha and beta adrenergic activity are adsorbed by coconut shell activated carbon from blood, sufficiently rapidly to markedly reduce the activity of these agents. The results of this study suggest that the site of injection of sympathomimetic agents being considered for correcting hypotension during activated carbon hemoperfusion be selected to permit systemic mixing before circulation into the adsorption device.

  11. Fractal analysis of granular activated carbons using isotherm data

    SciTech Connect

    Khalili, N.R.; Pan, M.; Sandi, G.

    1997-08-01

    Utilization of adsorption on solid surfaces was exercised for the first time in 1785. Practical application of unactivated carbon filters, and powdered carbon were first demonstrated in the American water treatment plant, and a municipal treatment plant in New Jersey, in 1883 and 1930, respectively. The use of activated carbon became widespread in the next few decades. At present, adsorption on carbons has a wide spread application in water treatment and removal of taste, odor, removal of synthetic organic chemicals, color-forming organics, and desinfection by-products and their naturally occurring precursors. This paper presents an analysis of the surface fractal dimension and adsorption capacity of a group of carbons.

  12. Selecting activated carbon for water and wastewater treatability studies

    SciTech Connect

    Zhang, W.; Chang, Q.G.; Liu, W.D.; Li, B.J.; Jiang, W.X.; Fu, L.J.; Ying, W.C.

    2007-10-15

    A series of follow-up investigations were performed to produce data for improving the four-indicator carbon selection method that we developed to identify high-potential activated carbons effective for removing specific organic water pollutants. The carbon's pore structure and surface chemistry are dependent on the raw material and the activation process. Coconut carbons have relatively more small pores than large pores; coal and apricot nutshell/walnut shell fruit carbons have the desirable pore structures for removing adsorbates of all sizes. Chemical activation, excessive activation, and/or thermal reactivation enlarge small pores, resulting in reduced phenol number and higher tannic acid number. Activated carbon's phenol, iodine, methylene blue, and tannic acid numbers are convenient indicators of its surface area and pore volume of pore diameters < 10, 10-15, 15-28, and > 28 angstrom, respectively. The phenol number of a carbon is also a good indicator of its surface acidity of oxygen-containing organic functional groups that affect the adsorptive capacity for aromatic and other small polar organics. The tannic acid number is an indicator of carbon's capacity for large, high-molecular-weight natural organic precursors of disinfection by-products in water treatment. The experimental results for removing nitrobenzene, methyl-tert-butyl ether, 4,4-bisphenol, humic acid, and the organic constituents of a biologically treated coking-plant effluent have demonstrated the effectiveness of this capacity-indicator-based method of carbon selection.

  13. Preparation of activated carbon monolith by application of phenolic resins as carbon precursors

    NASA Astrophysics Data System (ADS)

    Sajad, Mehran; Kazemzad, Mahmood; Hosseinnia, Azarmidokht

    2014-04-01

    In the current work, activated carbon monoliths have been prepared by application of different phenolic hydrocarbons namely catechol and resorcinol as carbon precursors. For synthesis of carbon monolith, the precursors have been mixed with Genapol PF-10 as template and then polymerized in the presence of lysine as catalyst. Then the polymerized monolith carbonized in inert atmosphere at 700°C and activated by water steam at 550°C. It was found that resorcinol polymerization is easier than catechol and occurred at 90°C while for polymerization of catechol elevated temperature of 120°C at hydrothermal condition is necessary. The prepared activated carbon samples have been characterized by various analysis methods including scanning electron microscopy (SEM), surface area measurement, and transmission electron microscopy (TEM). The adsorptions of three different aromatic hydrocarbons by the prepared activated carbon samples have also been investigated by high performance liquid chromatography (HPLC) and UV-Vis spectroscopy. It was found that carbon monolith prepared by catechol as carbon precursor has higher adsorpability and strength in comparison with the other sample. The higher performance of carbon monolith prepared by catechol can be associated with its higher active sites in comparison with resorcinol.

  14. Production and characterization of lignocellulosic biomass-derived activated carbon.

    PubMed

    Namazi, A B; Jia, C Q; Allen, D G

    2010-01-01

    The goal of this work is to establish the technical feasibility of producing activated carbon from pulp mill sludges. KOH chemical activation of four lignocellulosic biomass materials, two sludges from pulp mills, one sludge for a linerboard mill, and cow manure, were investigated experimentally, with a focus on the effects of KOH/biomass ratio (1/1, 1.5/1 and 2/1), activation temperature (400-600 °C) and activation time (1 to 2 h) on the development of porosity. The activation products were characterized for their physical and chemical properties using a surface area analyzer, scanning electron microscopy and Fourier transform infrared spectroscopy. Experiments were carried out to establish the effectiveness of the lignocellulosic biomass-derived activated carbon in removing methylene blue (MB), a surrogate of large organic molecules. The results show that the activated carbon are highly porous with specific surface area greater than 500 m²/g. The yield of activated carbon was greater than the percent of fixed carbon in the dry sludge, suggesting that the activation process was able to capture a substantial amount of carbon from the organic matter in the sludge. While 400 °C was too low, 600 °C was high enough to sustain a substantial rate of activation for linerboard sludge. The KOH/biomass ratio, activation temperature and time all play important roles in pore development and yield control, allowing optimization of the activation process. MB adsorption followed a Langmuir isotherm for all four activated carbon, although the adsorption capacity of NK-primary sludge-derived activated carbon was considerably lower than the rest, consistent with its lower specific surface area.

  15. Preparation and characterization of activated carbon produced from pomegranate seeds by ZnCl 2 activation

    NASA Astrophysics Data System (ADS)

    Uçar, Suat; Erdem, Murat; Tay, Turgay; Karagöz, Selhan

    2009-08-01

    In this study, pomegranate seeds, a by-product of fruit juice industry, were used as precursor for the preparation of activated carbon by chemical activation with ZnCl 2. The influence of process variables such as the carbonization temperature and the impregnation ratio on textural and chemical-surface properties of the activated carbons was studied. When using the 2.0 impregnation ratio at the carbonization temperature of 600 °C, the specific surface area of the resultant carbon is as high as 978.8 m 2 g -1. The results showed that the surface area and total pore volume of the activated carbons at the lowest impregnation ratio and the carbonization temperature were achieved as high as 709.4 m 2 g -1 and 0.329 cm 3 g -1. The surface area was strongly influenced by the impregnation ratio of activation reagent and the subsequent carbonization temperature.

  16. Soil Inorganic Carbon in Deserts: Active Carbon Sink or Inert Reservoir?

    NASA Astrophysics Data System (ADS)

    Monger, H. C.; Cole, D. R.

    2011-12-01

    Soil inorganic carbon is the third largest C pool in the active global carbon cycle, containing at least 800 petagrams of carbon. Although carbonate dissolution-precipitation reactions have been understood for over a century, the role of soil inorganic carbon in carbon sequestration, and in particular pedogenic carbonate, is a deceptively complex process because it involves interdependent connections among climate, plants, microorganisms, silicate minerals, soil moisture, pH, and Ca supply via rain, dust, or in situ weathering. An understanding of soil inorganic carbon as a sink or reservoir also requires examination of the system at local to continental scales and at seasonal to millennial time scales. In desert soils studied in North America, carbon isotope ratios and radiocarbon dates were measured in combination with electron microscopy, lab and field experiments with biological calcite formation, and field measurements of carbon dioxide emissions. These investigations reveal that soil inorganic carbon is both an active sink and a inert reservoir depending on the spatial and temporal scale and source of calcium.

  17. Cellulosic carbon fibers with branching carbon nanotubes for enhanced electrochemical activities for bioprocessing applications.

    PubMed

    Zhao, Xueyan; Lu, Xin; Tze, William Tai Yin; Kim, Jungbae; Wang, Ping

    2013-09-25

    Renewable biobased carbon fibers are promising materials for large-scale electrochemical applications including chemical processing, energy storage, and biofuel cells. Their performance is, however, often limited by low activity. Herein we report that branching carbon nanotubes can enhance the activity of carbonized cellulosic fibers, such that the oxidation potential of NAD(H) was reduced to 0.55 V from 0.9 V when applied for bioprocessing. Coordinating with enzyme catalysts, such hierarchical carbon materials effectively facilitated the biotransformation of glycerol, with the total turnover number of NAD(H) over 3500 within 5 h of reaction.

  18. Development and characterization of charcoal filled glass-composite materials made from SLS waste glass

    NASA Astrophysics Data System (ADS)

    Mustafa, Zaleha; Ismail, Mohd Ikwan; Juoi, Jariah Mohd; Shamsudin, Zurina; Rosli, Zulkifli M.; Fadzullah, Siti Hajar Sheikh Md; Othman, Radzali

    2015-07-01

    Glass-composite materials were prepared from the soda lime silicate (SLS) waste glass, ball clay and charcoal powder at various carbon content, of 1wt. % C, 5wt.% C and 10 wt.% C, fired to temperature of 850 °C as an alternative method for land site disposal method as well as effort for recycling waster glass. The effect of charcoal powder on the porosity, water absorption and hardness properties were studied. Phase analysis studies revealed the present of quartz (ICDD: 00001-0649, 2θ = 25.6° and 35.6°), cristobalite (ICDD 00004-0379, 2θ = 22.0° and 38.4°) and wollastonite (ICDD 00002-0689, 2θ = 30.1° and 26.9°). The results showed that the composite prepared from the mixture of 84 wt.% SLS, 1 wt.% of charcoal and 15 wt.% ball clay containing average pore size of 10 µm has projected optimized physical and mechanical properties. It is observed this batch has projected lowest water absorption percentage of 0.76 %, lowest porosity percentage of 1.76 %, highest 4.6 GPa for Vickers Microhardness.

  19. Mineral composition and charcoal determine the bacterial community structure in artificial soils.

    PubMed

    Ding, Guo-Chun; Pronk, Geertje Johanna; Babin, Doreen; Heuer, Holger; Heister, Katja; Kögel-Knabner, Ingrid; Smalla, Kornelia

    2013-10-01

    To study the influence of the clay minerals montmorillonite (M) and illite (I), the metal oxides ferrihydrite (F) and aluminum hydroxide (A), and charcoal (C) on soil bacterial communities, seven artificial soils with identical texture provided by quartz (Q) were mixed with sterilized manure as organic carbon source before adding a microbial inoculant derived from a Cambisol. Bacterial communities established in artificial soils after 90 days of incubation were compared by DGGE analysis of bacterial and taxon-specific 16S rRNA gene amplicons. The bacterial community structure of charcoal-containing soils highly differed from the other soils at all taxonomic levels studied. Effects of montmorillonite and illite were observed for Bacteria and Betaproteobacteria, but not for Actinobacteria or Alphaproteobacteria. A weak influence of metal oxides on Betaproteobacteria was found. Barcoded pyrosequencing of 16S rRNA gene amplicons done for QM, QI, QIF, and QMC revealed a high bacterial diversity in the artificial soils. The composition of the artificial soils was different from the inoculant, and the structure of the bacterial communities established in QMC soil was most different from the other soils, suggesting that charcoal provided distinct microenvironments and biogeochemical interfaces formed. Several populations with discriminative relative abundance between artificial soils were identified.

  20. Modeling polychlorinated biphenyl mass transfer after amendment of contaminated sediment with activated carbon

    SciTech Connect

    David Werner; Upal Ghosh; Richard G. Luthy

    2006-07-01

    The sorption kinetics and concentration of polychlorinated biphenyls (PCBs) in historically polluted sediment is modeled to assess a remediation strategy based on in situ PCB sequestration by mixing with activated carbon (AC). The authors extend their evaluation of a model based on intraparticle diffusion by including a biomimetic semipermeable membrane device (SPMD) and a first-order degradation rate for the aqueous phase. The model predictions are compared with the previously reported experimental PCB concentrations in the bulk water phase and in SPMDs. The simulated scenarios comprise a marine and a freshwater sediment, four PCB congeners, two AC grain sizes, four doses of AC, and comparison with laboratory experiments. The modeling approach distinguishes between two different sediment particles types: a light-density fraction representing carbonaceous particles such as charcoal, coal, coke, cenospheres, or wood, and a heavy-density fraction representing the mineral phase with coatings of organic matter. A third particle type in the numerical model is AC. The model qualitatively reproduces the observed shifts in the PCB distribution during repartitioning after AC amendment but overestimates the overall effect of the treatment in reducing aqueous and SPMD concentrations of PCBs by a factor of 2-6. For the AC application in sediment, competitive sorption of the various solutes apparently requires a reduction by a factor of 16 of the literature values for the AC-water partitioning coefficient measured in pure aqueous systems. With this correction, model results and measurements agree within a factor of 3. After AC amendment is homogeneously mixed into the sediment and then left undisturbed, aqueous PCB concentrations tend toward the same reduction after 5 years. 19 refs., 5 figs., 4 tabs.

  1. Storage stability of ketones on carbon adsorbents.

    PubMed

    Prado, C; Alcaraz, M J; Fuentes, A; Garrido, J; Periago, J F

    2006-09-29

    Activated coconut carbon constitutes the more widely used sorbent for preconcentration of volatile organic compounds in sampling workplace air. Water vapour is always present in the air and its adsorption on the activated carbon surface is a serious drawback, mainly when sampling polar organic compounds, such as ketones. In this case, the recovery of the compounds diminishes; moreover, ketones can be decomposed during storage. Synthetic carbons contain less inorganic impurities and have a lower capacity for water adsorption than coconut charcoal. The aim of this work was to evaluate the storage stability of various ketones (acetone, 2-butanone, 4-methyl-2-pentanone and cyclohexanone) on different activated carbons and to study the effect of adsorbed water vapour under different storage conditions. The effect of storage temperature on extraction efficiencies was significant for each ketone in all the studied sorbents. Recovery was higher when samples were stored at 4 degrees C. The results obtained for storage stability of the studied ketones showed that the performance of synthetic carbons was better than for the coconut charcoals. The water adsorption and the ash content of the carbons can be a measure of the reactive sites that may chemisorb ketones or catalize their decomposition. Anasorb 747 showed good ketone stability at least for 7 days, except for cyclohexanone. After 30-days storage, the stability of the studied ketones was excellent on Carboxen 564. This sorbent had a nearly negligible ash content and the adsorbed water was much lower than for the other sorbents tested.

  2. Hydrogen adsorption on functionalized nanoporous activated carbons.

    PubMed

    Zhao, X B; Xiao, B; Fletcher, A J; Thomas, K M

    2005-05-12

    There is considerable interest in hydrogen adsorption on carbon nanotubes and porous carbons as a method of storage for transport and related energy applications. This investigation has involved a systematic investigation of the role of functional groups and porous structure characteristics in determining the hydrogen adsorption characteristics of porous carbons. Suites of carbons were prepared with a wide range of nitrogen and oxygen contents and types of functional groups to investigate their effect on hydrogen adsorption. The porous structures of the carbons were characterized by nitrogen (77 K) and carbon dioxide (273 K) adsorption methods. Hydrogen adsorption isotherms were studied at 77 K and pressure up to 100 kPa. All the isotherms were Type I in the IUPAC classification scheme. Hydrogen isobars indicated that the adsorption of hydrogen is very temperature dependent with little or no hydrogen adsorption above 195 K. The isosteric enthalpies of adsorption at zero surface coverage were obtained using a virial equation, while the values at various surface coverages were obtained from the van't Hoff isochore. The values were in the range 3.9-5.2 kJ mol(-1) for the carbons studied. The thermodynamics of the adsorption process are discussed in relation to temperature limitations for hydrogen storage applications. The maximum amounts of hydrogen adsorbed correlated with the micropore volume obtained from extrapolation of the Dubinin-Radushkevich equation for carbon dioxide adsorption. Functional groups have a small detrimental effect on hydrogen adsorption, and this is related to decreased adsorbate-adsorbent and increased adsorbate-adsorbate interactions.

  3. Ancient charcoal as a natural archive for paleofire regime and vegetation change in the Mayumbe, Democratic Republic of the Congo

    NASA Astrophysics Data System (ADS)

    Hubau, Wannes; Van den Bulcke, Jan; Kitin, Peter; Mees, Florias; Baert, Geert; Verschuren, Dirk; Nsenga, Laurent; Van Acker, Joris; Beeckman, Hans

    2013-09-01

    Charcoal was sampled in four soil profiles at the Mayumbe forest boundary (DRC). Five fire events were recorded and 44 charcoal types were identified. One stratified profile yielded charcoal assemblages around 530 cal yr BP and > 43.5 cal ka BP in age. The oldest assemblage precedes the period of recorded anthropogenic burning, illustrating occasional long-term absence of fire but also natural wildfire occurrences within tropical rainforest. No other charcoal assemblages older than 2500 cal yr BP were recorded, perhaps due to bioturbation and colluvial reworking. The recorded paleofires were possibly associated with short-lived climate anomalies. Progressively dry climatic conditions since ca. 4000 cal yr BP onward did not promote paleofire occurrence until increasing seasonality affected vegetation at the end of the third millennium BP, as illustrated by a fire occurring in mature rainforest that persisted until around 2050 cal yr BP. During a drought episode coinciding with the 'Medieval Climate Anomaly', mature rainforest was locally replaced by woodland savanna. Charcoal remains from pioneer forest indicate that fire hampered forest regeneration after climatic drought episodes. The presence of pottery shards and oil-palm endocarps associated with two relatively recent paleofires suggests that the effects of climate variability were amplified by human activities.

  4. Adsorption of methylene blue dye onto activated carbons based on agricultural by-products: equilibrium and kinetic studies.

    PubMed

    Ioannou, Z; Simitzis, J

    2013-01-01

    Mixtures of novolac resin and olive stone biomass (20/80 and 40/60 w/w) were cured, pyrolyzed up to 1,000 °C and activated with CO2 under a continuous flow operation (named N20B-cCa and N40B-cCa respectively). Commercial activated charcoal was similarly re-activated with CO2 and used for comparison reasons (AC-a). The characterization of these materials was performed by Fourier transform Infrared (FTIR) analysis and their specific surface area was determined according to DIN 66132. The materials were tested for their adsorption abilities at different temperatures (298, 333 K) and initial dye concentrations (0.01-0.35 g/L) using 1 L of methylene blue (MB) solution in 10 g of activated carbon. MB adsorption kinetic was also studied. The FTIR spectra of all activated carbons show absorption peaks which correspond to -OH, -CH, -C-O-C- groups and to aromatic ring. The presence of the absorption peak at about 1,400 cm(-1) for N20B-cCa, N40B-cCa indicates more acidic groups on them compared to the commercial AC-a. The specific surface area of N20B-cCa, N40B-cCa and AC-a has values equal to 352, 342 and 760 m(2)/g respectively. From the applied kinetic models, pseudo-second-order equation could best describe MB adsorption. Consequently, such adsorbents can be used as filters to adsorb dyes from wastewaters.

  5. Select metal adsorption by activated carbon made from peanut shells.

    PubMed

    Wilson, Kermit; Yang, Hong; Seo, Chung W; Marshall, Wayne E

    2006-12-01

    Agricultural by-products, such as peanut shells, contribute large quantities of lignocellulosic waste to the environment each growing season; but few, if any, value-added uses exist for their disposal. The objective of this study was to convert peanut shells to activated carbons for use in adsorption of select metal ions, namely, cadmium (Cd2+), copper (Cu2+), lead (Pb2+), nickel (Ni2+) and zinc (Zn2+). Milled peanut shells were pyrolyzed in an inert atmosphere of nitrogen gas, and then activated with steam at different activation times. Following pyrolysis and activation, the carbons underwent air oxidation. The prepared carbons were evaluated either for adsorption efficiency or adsorption capacity; and these parameters were compared to the same parameters obtained from three commercial carbons, namely, DARCO 12x20, NORIT C GRAN and MINOTAUR. One of the peanut shell-based carbons had metal ion adsorption efficiencies greater than two of the three commercial carbons but somewhat less than but close to Minotaur. This study demonstrates that peanut shells can serve as a source for activated carbons with metal ion-removing potential and may serve as a replacement for coal-based commercial carbons in applications that warrant their use.

  6. Role of nitrogen in pore development in activated carbon prepared by potassium carbonate activation of lignin

    NASA Astrophysics Data System (ADS)

    Tsubouchi, Naoto; Nishio, Megumi; Mochizuki, Yuuki

    2016-05-01

    The present work focuses on the role of nitrogen in the development of pores in activated carbon produced from lignin by K2CO3 activation, employing a fixed bed reactor under a high-purity He stream at temperatures of 500-900 °C. The specific surface area and pore volume obtained by activation of lignin alone are 230 m2/g and 0.13 cm3/g at 800 °C, and 540 m2/g and 0.31 cm3/g at 900 °C, respectively. Activation of a mixture of lignin and urea provides a significant increase in the surface area and volume, respectively reaching 3300-3400 m2/g and 2.0-2.3 cm3/g after holding at 800-900 °C for 1 h. Heating a lignin/urea/K2CO3 mixture leads to a significant decrease in the yield of released N-containing gases compared to the results for urea alone and a lignin/urea mixture, and most of the nitrogen in the urea is retained in the solid phase. X-ray photoelectron spectroscopy and X-ray diffraction analyses clearly show that part of the remaining nitrogen is present in heterocyclic structures (for example, pyridinic and pyrrolic nitrogen), and the rest is contained as KOCN at ≤600 °C and as KCN at ≥700 °C, such that the latter two compounds can be almost completely removed by water washing. The fate of nitrogen during heating of lignin/urea/K2CO3 and role of nitrogen in pore development in activated carbon are discussed on the basis of the results mentioned above.

  7. Sink effect in activated carbon-supported hydrodesulfurization catalysts

    SciTech Connect

    Laine, J.; Labady, M.; Severino, F.; Yunes, S.

    1997-03-01

    A synergistic effect has been proposed in previous papers, attempting to explain the higher activity of activated carbon-supported hydrodesulfurization (HDS) catalysts with respect to conventional alumina-supported catalysts, reported earlier. However, activated carbon characteristics can be strongly affected by the raw material and the method of activation. Thus, previous work using Ni-Mo catalysts supported on two different activated carbons (one prepared by {open_quotes}physical{close_quotes} and the other by {open_quotes}chemical{close_quotes} activation) showed different optimal Ni concentrations for higher HDS activity, such difference being attributed to the predominance of Topsoe`s Type I {open_quotes}NiMoS{close_quotes} phase in one carbon and the predominance of Type II in the other. Due to the lack of proper characterization of the activated carbon supported catalysts of the previous work, this paper presents further data suggesting that microporosity provided by the activated carbon may be the responsible for the above referred synergism. 12 refs., 1 fig., 3 tabs.

  8. Grafting of activated carbon cloths for selective adsorption

    NASA Astrophysics Data System (ADS)

    Gineys, M.; Benoit, R.; Cohaut, N.; Béguin, F.; Delpeux-Ouldriane, S.

    2016-05-01

    Chemical functionalization of an activated carbon cloth with 3-aminophthalic acid and 4-aminobenzoic acid groups by the in situ formation of the corresponding diazonium salt in aqueous acidic solution is reported. The nature and amount of selected functions on an activated carbon surface, in particular the grafted density, were determined by potentiometric titration, elemental analysis and X-ray photoelectron spectroscopy (XPS). The nanotextural properties of the modified carbon were explored by gas adsorption. Functionalized activated carbon cloth was obtained at a discrete grafting level while preserving interesting textural properties and a large porous volume. Finally, the grafting homogeneity of the carbon surface and the nature of the chemical bonding were investigated using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) technique.

  9. JV Task 90 - Activated Carbon Production from North Dakota Lignite

    SciTech Connect

    Steven Benson; Charlene Crocker; Rokan Zaman; Mark Musich; Edwin Olson

    2008-03-31

    The Energy & Environmental Research Center (EERC) has pursued a research program for producing activated carbon from North Dakota lignite that can be competitive with commercial-grade activated carbon. As part of this effort, small-scale production of activated carbon was produced from Fort Union lignite. A conceptual design of a commercial activated carbon production plant was drawn, and a market assessment was performed to determine likely revenue streams for the produced carbon. Activated carbon was produced from lignite coal in both laboratory-scale fixed-bed reactors and in a small pilot-scale rotary kiln. The EERC was successfully able to upgrade the laboratory-scale activated carbon production system to a pilot-scale rotary kiln system. The activated carbon produced from North Dakota lignite was superior to commercial grade DARCO{reg_sign} FGD and Rheinbraun's HOK activated coke product with respect to iodine number. The iodine number of North Dakota lignite-derived activated carbon was between 600 and 800 mg I{sub 2}/g, whereas the iodine number of DARCO FGD was between 500 and 600 mg I{sub 2}/g, and the iodine number of Rheinbraun's HOK activated coke product was around 275 mg I{sub 2}/g. The EERC performed both bench-scale and pilot-scale mercury capture tests using the activated carbon made under various optimization process conditions. For comparison, the mercury capture capability of commercial DARCO FGD was also tested. The lab-scale apparatus is a thin fixed-bed mercury-screening system, which has been used by the EERC for many mercury capture screen tests. The pilot-scale systems included two combustion units, both equipped with an electrostatic precipitator (ESP). Activated carbons were also tested in a slipstream baghouse at a Texas power plant. The results indicated that the activated carbon produced from North Dakota lignite coal is capable of removing mercury from flue gas. The tests showed that activated carbon with the greatest iodine number

  10. Activated carbon fibers and engineered forms from renewable resources

    DOEpatents

    Baker, Frederick S.

    2010-06-01

    A method of producing activated carbon fibers (ACFs) includes the steps of providing a natural carbonaceous precursor fiber material, blending the carbonaceous precursor material with a chemical activation agent to form chemical agent-impregnated precursor fibers, spinning the chemical agent-impregnated precursor material into fibers, and thermally treating the chemical agent-impregnated precursor fibers. The carbonaceous precursor material is both carbonized and activated to form ACFs in a single step. The method produces ACFs exclusive of a step to isolate an intermediate carbon fiber.

  11. Activated carbon fibers and engineered forms from renewable resources

    DOEpatents

    Baker, Frederick S

    2013-02-19

    A method of producing activated carbon fibers (ACFs) includes the steps of providing a natural carbonaceous precursor fiber material, blending the carbonaceous precursor material with a chemical activation agent to form chemical agent-impregnated precursor fibers, spinning the chemical agent-impregnated precursor material into fibers, and thermally treating the chemical agent-impregnated precursor fibers. The carbonaceous precursor material is both carbonized and activated to form ACFs in a single step. The method produces ACFs exclusive of a step to isolate an intermediate carbon fiber.

  12. Nickel adsorption by sodium polyacrylate-grafted activated carbon.

    PubMed

    Ewecharoen, A; Thiravetyan, P; Wendel, E; Bertagnolli, H

    2009-11-15

    A novel sodium polyacrylate grafted activated carbon was produced by using gamma radiation to increase the number of functional groups on the surface. After irradiation the capacity for nickel adsorption was studied and found to have increased from 44.1 to 55.7 mg g(-1). X-ray absorption spectroscopy showed that the adsorbed nickel on activated carbon and irradiation-grafted activated carbon was coordinated with 6 oxygen atoms at 2.04-2.06 A. It is proposed that this grafting technique could be applied to other adsorbents to increase the efficiency of metal adsorption.

  13. Activation of peroxymonosulfate by graphitic carbon nitride loaded on activated carbon for organic pollutants degradation.

    PubMed

    Wei, Mingyu; Gao, Long; Li, Jun; Fang, Jia; Cai, Wenxuan; Li, Xiaoxia; Xu, Aihua

    2016-10-05

    Graphitic carbon nitride supported on activated carbon (g-C3N4/AC) was prepared through an in situ thermal approach and used as a metal free catalyst for pollutants degradation in the presence of peroxymonosulfate (PMS) without light irradiation. It was found that g-C3N4 was highly dispersed on the surface of AC with the increase of surface area and the exposition of more edges and defects. The much easier oxidation of C species in g-C3N4 to CO was also observed from XPS spectra. Acid Orange 7 (AO7) and other organic pollutants could be completely degraded by the g-C3N4/AC catalyst within 20min with PMS, while g-C3N4+PMS and AC+PMS showed no significant activity for the reaction. The performance of the catalyst was significantly influenced by the amount of g-C3N4 loaded on AC; but was nearly not affected by the initial solution pH and reaction temperature. In addition, the catalysts presented good stability. A nonradical mechanism accompanied by radical generation (HO and SO4(-)) in AO7 oxidation was proposed in the system. The CO groups play a key role in the process; while the exposure of more N-(C)3 group can further increase its electron density and basicity. This study can contribute to the development of green materials for sustainable remediation of aqueous organic pollutants.

  14. Physicochemical and porosity characteristics of thermally regenerated activated carbon polluted with biological activated carbon process.

    PubMed

    Dong, Lihua; Liu, Wenjun; Jiang, Renfu; Wang, Zhansheng

    2014-11-01

    The characteristics of thermally regenerated activated carbon (AC) polluted with biological activated carbon (BAC) process were investigated. The results showed that the true micropore and sub-micropore volume, pH value, bulk density, and hardness of regenerated AC decreased compared to the virgin AC, but the total pore volume increased. XPS analysis displayed that the ash contents of Al, Si, and Ca in the regenerated AC respectively increased by 3.83%, 2.62% and 1.8%. FTIR spectrum showed that the surface functional groups of virgin and regenerated AC did not change significantly. Pore size distributions indicated that the AC regeneration process resulted in the decrease of micropore and macropore (D>10 μm) volume and the increase of mesopore and macropore (0.1 μm

  15. Preparation of activated carbons from agricultural residues for pesticide adsorption.

    PubMed

    Ioannidou, Ourania A; Zabaniotou, Anastasia A; Stavropoulos, George G; Islam, Md Azharul; Albanis, Triantafyllos A

    2010-09-01

    Activated carbons (ACs) can be used not only for liquid but also for vapour phase applications, such as water treatment, deodorisation, gas purification and air treatment. In the present study, activated carbons produced from agricultural residues (olive kernel, corn cobs, rapeseed stalks and soya stalks) via physical steam activation were tested for the removal of Bromopropylate (BP) from water. For the characterization of the activated carbons ICP, SEM, FTIR and XRD analyses were performed. Adsorption kinetics and equilibrium isotherms were investigated for all biomass activated carbons in aqueous solutions. Experimental data of BP adsorption have fitted best to the pseudo 2nd-order kinetic model and Langmuir isotherm. The study resulted that corn cobs showed better adsorption capacity than the other biomass ACs. Comparison among ACs from biomass and commercial ones (F400 and Norit GL50) revealed that the first can be equally effective for the removal of BP from water with the latter.

  16. Use of activated carbon coated with bentonite for increasing the sensitivity of pcr detection of Escherichia coli O157:H7 in Canadian oyster (Crassostrea gigas) tissue.

    PubMed

    Luan, Chunguang; Levin, Robert E

    2008-01-01

    A novel method for directly increasing the recovery of Escherichia coli O157:H7 and efficiently eliminating PCR inhibitors in oyster tissue without preenrichment was developed with the use of activated carbon coated with bentonite. The recovery of E. coli O157:H7 was significantly affected by the amount of bentonite used to coat the activated charcoal and the pH value of sample preparations. When 4.2 g of activated carbon were coated with 0.4 g of bentonite and seeded oyster samples were adjusted to a pH of 5.0, a high recovery of E. coli O157:H7 (91.6+/-4.4%) was obtained. Activated carbon, coated with bentonite, allowed the PCR detection of 1.5 x 10(2) CFU/g of oyster tissue which was equivalent to 30 genomic targets per PCR reaction. Without the use of activated carbon coated with bentonite, the minimum level of detection was 1.5 x 10(5) CFU/g of oyster tissue, which is equivalent to 3.0 x 10(4) genomic targets per PCR reaction. Three commercial DNA purification systems were used for comparison. The limit of detection with the Wizard DNA Clean-Up System and the Chelex(R)100 Resin was 1.5 x 10(3) CFU/g of oyster tissue which was equivalent to 3.0 x 10(2) CFU/PCR reaction. The QIAamp DNA Mini Kit resulted in a detection limit of 5 x 10(2) CFU/g of oyster tissue which was equivalent to 5 x 10(2) genomic targets per PCR reaction. The use of activated carbon coated with bentonite is an inexpensive method for removal of PCR inhibitors from tissue samples prior to the release of DNA from target cells resulting in relatively low numbers of target cells detected without enrichment.

  17. Hydrogen storage on activated carbon. Final report

    SciTech Connect

    Schwarz, J.A.

    1994-11-01

    The project studied factors that influence the ability of carbon to store hydrogen and developed techniques to enhance that ability in naturally occurring and factory-produced commercial carbon materials. During testing of enhanced materials, levels of hydrogen storage were achieved that compare well with conventional forms of energy storage, including lead-acid batteries, gasoline, and diesel fuel. Using the best materials, an electric car with a modern fuel cell to convert the hydrogen directly to electricity would have a range of over 1,000 miles. This assumes that the total allowable weight of the fuel cell and carbon/hydrogen storage system is no greater than the present weight of batteries in an existing electric vehicle. By comparison, gasoline cars generally are limited to about a 450-mile range, and battery-electric cars to 40 to 60 miles. The project also developed a new class of carbon materials, based on polymers and other organic compounds, in which the best hydrogen-storing factors discovered earlier were {open_quotes}molecularly engineered{close_quotes} into the new materials. It is believed that these new molecularly engineered materials are likely to exceed the performance of the naturally occurring and manufactured carbons seen earlier with respect to hydrogen storage.

  18. ELEMENTAL MERCURY CAPTURE BY ACTIVATED CARBON IN A FLOW REACTOR

    EPA Science Inventory


    The paper gives results of bench-scale experiments in a flow reactor to simulate the entrained-flow capture of elemental mercury (Hgo) using solid sorbents. Adsorption of Hgo by a lignite-based activated carbon (Calgon FGD) was examined at different carbon/mercury (C/Hg) rat...

  19. Activated carbon testing for the 200 area effluent treatment facility

    SciTech Connect

    Wagner, R.N.

    1997-01-17

    This report documents pilot and laboratory scale testing of activated carbon for use in the 200 Area Effluent Treatment Facility peroxide decomposer columns. Recommendations are made concerning column operating conditions and hardware design, the optimum type of carbon for use in the plant, and possible further studies.

  20. Reduction of the polycyclic aromatic hydrocarbon (PAH) content of charcoal smoke during grilling by charcoal preparation using high carbonisation and a preheating step.

    PubMed

    Chaemsai, Suriyapong; Kunanopparat, Thiranan; Srichumpuang, Jidapa; Nopharatana, Montira; Tangduangdee, Chairath; Siriwattanayotin, Suwit

    2016-01-01

    Charcoal-grilling may lead to contamination of food with carcinogenic polycyclic aromatic hydrocarbons (PAHs) during the grilling process. The objective of this work was to determine the effect of charcoal preparation on 16 USEPA priority PAHs in the smoke produced during the grilling process. Firstly, mangrove charcoal was prepared at carbonisation temperatures of 500, 750 and 1000 °C. The charcoal were then preheated by burning at 650 °C. This preheating step is usually used to prepare hot charcoal for the grilling process in the food industry. In this study, charcoal was preheated at different burning times at 5, 20 min and 5 h, at which time partial and whole charcoal glowed, and charcoal was completely burnt, respectively. Finally, PAHs in the smoke were collected and determined by GC/MS. The result showed that charcoal prepared at a carbonisation temperature of 500 °C had higher levels of PAHs released into the smoke. In contrast, charcoal produced at 750 and 1000 °C had lower PAHs released for all burning times. In addition, PAHs released for 5, 20 min and 5 h of burning time were about 19.9, 1.2 and 0.7 µg g(-1) dry charcoal for charcoal produced at 500 °C, and about 0.9-1.4, 0.8-1.2 and 0.15-0.3 µg g(-1) dry charcoal for charcoal produced at 750 and 1000 °C, respectively. Therefore, this research suggests that food grilled using charcoal carbonised at a high temperature of about 750 °C presents a lower risk of PAH contamination. In addition, in the preheating step, whole charcoal should fully glow in order to reduce the PAH content in charcoal before grilling.

  1. Predicting distributions of charcoal in Amazonian soils: approaches from earth and space

    NASA Astrophysics Data System (ADS)

    McMichael, C.; Palace, M. W.; Bush, M. B.; Braswell, R.; Hagen, S. C.; Czarnecki, C.; Neves, E.; Raczka, M.

    2011-12-01

    The direct linkage between fire and human activity in Amazonian rainforests is evidenced in both remote sensing datasets and field-based research. Paleoecological and archaeological data suggest the synergy has persisted millennia, and that human populations may have equaled modern numbers before European contact. Pre-Columbian people used fire to clear forests, but also combined charcoal with other materials to form Amazonian Black Earths (ABE), a nutrient rich anthrosol believed to be capable of sustaining large-scale permanent societies in such nutrient-poor tropical settings. The majority of impacted sites are found on bluffs overlooking Amazonian rivers, which are considered 'preferred' settings. Here, we examine predictions about preferred settings and the distributions of charcoal resulting from pre-Columbian human activity in western and central Amazonia using proxies from both earth and space. Soil sampling, stratified based on distance from river and forest seasonality, was used to determine whether preferred locations had higher probabilities of impacts. We analyzed more than 351 soil cores for ABE and macroscopic charcoal (> 500 μm) in the upper 20 cm of soil (representing modern fires), and in soils > 20 cm depth (representing historic fires). ABE was absent from all sites, but logistic regressions indicated that probabilities of finding soil charcoal significantly decreased as distance from river increased in aseasonal forests. However, in more seasonal forests, the probability of finding charcoal was increased, although distance from river was not a significant factor. Alternately, the location of ABE and charcoal mainly along major rivers may be an artifact of sampling. To look at distributions of ABE across broad spatial scales that may not be accessible from the ground, we used Hyperion satellite images to detect canopy chemistry differences resulting from various soil nutrients (i.e. soil enrichment occurring at ABE sites). Our initial findings

  2. Selection and preparation of activated carbon for fuel gas storage

    DOEpatents

    Schwarz, James A.; Noh, Joong S.; Agarwal, Rajiv K.

    1990-10-02

    Increasing the surface acidity of active carbons can lead to an increase in capacity for hydrogen adsorption. Increasing the surface basicity can facilitate methane adsorption. The treatment of carbons is most effective when the carbon source material is selected to have a low ash content i.e., below about 3%, and where the ash consists predominantly of alkali metals alkali earth, with only minimal amounts of transition metals and silicon. The carbon is washed in water or acid and then oxidized, e.g. in a stream of oxygen and an inert gas at an elevated temperature.

  3. TESTING GUIDELINES FOR TECHNETIUM-99 ABSORPTION ON ACTIVATED CARBON

    SciTech Connect

    BYRNES ME

    2010-09-08

    CH2M HILL Plateau Remediation Company (CHPRC) is currently evaluating the potential use of activated carbon adsorption for removing technetium-99 from groundwater as a treatment method for the Hanford Site's 200 West Area groundwater pump-and-treat system. The current pump-and-treat system design will include an ion-exchange (IX) system for selective removal of technetium-99 from selected wells prior to subsequent treatment of the water in the central treatment system. The IX resin selected for technetium-99 removal is Purolite A530E. The resin service life is estimated to be approximately 66.85 days at the design technetium-99 loading rate, and the spent resin must be replaced because it cannot be regenerated. The resulting operating costs associated with resin replacement every 66.85 days are estimated at $0.98 million/year. Activated carbon pre-treatment is being evaluated as a potential cost-saving measure to offset the high operating costs associated with frequent IX resin replacement. This document is preceded by the Literature Survey of Technetium-99 Groundwater Pre-Treatment Option Using Granular Activated Carbon (SGW-43928), which identified and evaluated prior research related to technetium-99 adsorption on activated carbon. The survey also evaluated potential operating considerations for this treatment approach for the 200 West Area. The preliminary conclusions of the literature survey are as follows: (1) Activated carbon can be used to selectively remove technetium-99 from contaminated groundwater. (2) Technetium-99 adsorption onto activated carbon is expected to vary significantly based on carbon types and operating conditions. For the treatment approach to be viable at the Hanford Site, activated carbon must be capable of achieving a designated minimum technetium-99 uptake. (3) Certain radionuclides known to be present in 200 West Area groundwater are also likely to adsorb onto activated carbon. (4) Organic solvent contaminants of concern (COCs) will

  4. INTERIOR DETAIL, STOVE. SMALL CHARCOAL FIRES WERE LIT IN THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR DETAIL, STOVE. SMALL CHARCOAL FIRES WERE LIT IN THE DEPRESSIONS, WHICH WERE COVERED WITH IRON GRATES TO SUSPEND POTS OVER THE HEAT SOURCE - The Woodlands, 4000 Woodlands Avenue, Philadelphia, Philadelphia County, PA

  5. 24. Photocopy of photograph. VIEW OF CHARCOAL KILNS AND IRON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. Photocopy of photograph. VIEW OF CHARCOAL KILNS AND IRON PLANT FROM SOUTH END OF BEACH, probably 1901. (From the Robert Teagle Private Collection, Port Townsend, WA) - Irondale Iron & Steel Plant, Port Townsend, Jefferson County, WA

  6. Formation of charcoal from biomass in a sealed reactor

    SciTech Connect

    Mok, W.S.L.; Antal, M.J. Jr. ); Szabo, P.; Varhegyi, G.; Zelei, B. )

    1992-04-01

    In this paper, samples o cellulose, hemicellulose, lignin, and nine species of whole biomass are pyrolyzed in sealed reactors. Very high charcoal yields (e.g., 40% from cellulose, 48% from Eucalyptus gummifera) were obtained. Higher sample loading (sample mass per unit reactor volume) increased charcoal yield and the associated exothermic heat release and lowered the reaction onset temperature. These effects were induced by the vapor-phase concentrations of the volatile products, and not the system pressure. Addition of water catalyzed the reaction and increased the char yield. These observations suggest that charcoal formation is autocatalyzed by water, an initial pyrolysis product. When whole biomass was used as a feedstock, higher charcoal yields were obtained from species with high lignin and/or low hemicellulose content.

  7. Comparing black carbon types in sequestering polybrominated diphenyl ethers (PBDEs) in sediments

    PubMed Central

    Jia, Fang; Gan, Jay

    2014-01-01

    Polybrominated diphenyl ethers (PBDEs) are widely found in sediments, especially congeners from the penta-BDE formula. Due to their strong affinity for black carbon (BC), bioavailability of PBDEs may be decreased in BC-amended sediments. In this study, we used a matrix-SPME method to measure the freely dissolved concentration (Cfree) of PBDEs as a parameter of their potential bioavailability and evaluated the differences among biochar, charcoal, and activated carbon. Activated carbon displayed a substantially greater sequestration capacity than biochar or charcoal. At 1% amendment rate in sediment with low organic carbon (OC) content (0.12%), Cfree of six PBDEs was reduced by 47.5–78.0%, 47.3–77.5%, and 94.1–98.3% with biochar, charcoal, and activated carbon, respectively, while the sequestration was more limited in sediment with high OC content (0.87%). Therefore, it is important to consider the type and properties of the BC and the sediment in BC-based remediation or mitigation. PMID:24047549

  8. Quality of poultry litter-derived granular activated carbon.

    PubMed

    Qiu, Guannan; Guo, Mingxin

    2010-01-01

    Utilization of poultry litter as a source material for generating activated carbon is a value-added and environmentally beneficial approach to recycling organic waste. In this study, the overall quality of poultry litter-derived granular activated carbon was systematically evaluated based on its various physical and chemical properties. Granular activated carbon generated from pelletized poultry litter following a typical steam-activation procedure possessed numerous micropores in the matrix. The product exhibited a mean particle diameter of 2.59 mm, an apparent density of 0.45 g cm(-3), a ball-pan hardness of 91.0, an iodine number of 454 mg g(-1), and a BET surface area of 403 m(2) g(-1). It contained high ash, nitrogen, phosphorus contents and the trace elements Cu, Zn, and As. Most of the nutrients and toxic elements were solidified and solution-unextractable. In general, poultry litter-based activated carbon demonstrated overall quality comparable to that of low-grade commercial activated carbon derived from coconut shell and bituminous coal. It is promising to use poultry litter as a feedstock to manufacture activated carbon for wastewater treatment.

  9. Natural gas storage with activated carbon from a bituminous coal

    USGS Publications Warehouse

    Sun, Jielun; Rood, M.J.; Rostam-Abadi, M.; Lizzio, A.A.

    1996-01-01

    Granular activated carbons ( -20 + 100 mesh; 0.149-0.84 mm) were produced by physical activation and chemical activation with KOH from an Illinois bituminous coal (IBC-106) for natural gas storage. The products were characterized by BET surface area, micropore volume, bulk density, and methane adsorption capacities. Volumetric methane adsorption capacities (Vm/Vs) of some of the granular carbons produced by physical activation are about 70 cm3/cm3 which is comparable to that of BPL, a commercial activated carbon. Vm/Vs values above 100 cm3/cm3 are obtainable by grinding the granular products to - 325 mesh (<0.044 mm). The increase in Vm/Vs is due to the increase in bulk density of the carbons. Volumetric methane adsorption capacity increases with increasing pore surface area and micropore volume when normalizing with respect to sample bulk volume. Compared with steam-activated carbons, granular carbons produced by KOH activation have higher micropore volume and higher methane adsorption capacities (g/g). Their volumetric methane adsorption capacities are lower due to their lower bulk densities. Copyright ?? 1996 Elsevier Science Ltd.

  10. Sustainable Regeneration of Nanoparticle Enhanced Activated Carbon in Water

    EPA Science Inventory

    The regeneration and reuse of exhausted granular activated carbon (GAC) is an appropriate method for lowering operational and environmental costs. Advanced oxidation is a promising environmental friendly technique for GAC regeneration. The main objective of this research was to ...

  11. [Influence of biological activated carbon dosage on landfill leachate treatment].

    PubMed

    Cui, Yan-Rui; Guo, Yan; Wu, Qing

    2014-08-01

    Effects of biological activated carbon (BAC) dosage on COD removal in landfill leachate treatment were compared. The COD removal efficiency of reactors with 0, 100 and 300 g activated carbon dosage per litre activated sludge was 12.9%, 19.6% and 27.7%, respectively. The results indicated that BAC improved the refractory organic matter removal efficiency and there was a positive correlation between COD removal efficiency and BAC dosage. The output of carbon dioxide after 8h of aeration in reactors was 109, 193 and 306 mg corresponding to the activated carbon dosages mentioned above, which indicated the amount of biodegradation and BAC dosage also had a positive correlation. The combination of adsorption and bioregeneration of BAC resulted in the positive correlation betweem organic matter removal efficiency and BAC dosage, and bioregeneration was the root cause for the microbial decomposition of refractory organics.

  12. Nanoscale charcoal powder induced saturable absorption and mode-locking of a low-gain erbium-doped fiber-ring laser

    NASA Astrophysics Data System (ADS)

    Lin, Yung-Hsiang; Chi, Yu-Chieh; Lin, Gong-Ru

    2013-05-01

    Triturated charcoal nano-powder directly brushed on a fiber connector end-face is used for the first time as a fast saturable absorber for a passively mode-locked erbium-doped fiber-ring laser (EDFL). These dispersant-free charcoal nano-powders with a small amount of crystalline graphene phase and highly disordered carbon structure exhibit a broadened x-ray diffraction peak and their Raman spectrum shows the existence of a carbon related D-band at 1350 cm-1 and the disappearance of the 2D-band peak at 2700 cm-1. The charcoal nano-powder exhibits a featureless linear absorbance in the infrared region with its linear transmittance of 0.66 nonlinearly saturated at 0.73 to give a ΔT/T of 10%. Picosecond mode-locking at a transform-limited condition of a low-gain EDFL is obtained by using the charcoal nano-powder. By using a commercial EDFA with a linear gain of only 17 dB at the saturated output power of 17.5 dB m required to initiate the saturable absorption of the charcoal nano-powder, the EDFL provides a pulsewidth narrowing from 3.3 to 1.36 ps associated with its spectral linewidth broadening from 0.8 to 1.83 nm on increasing the feedback ratio from 30 to 90%. This investigation indicates that all the carbon-based materials containing a crystalline graphene phase can be employed to passively mode-lock the EDFL, however, the disordered carbon structure inevitably induces a small modulation depth and a large mode-locking threshold, thus limiting the pulsewidth shortening. Nevertheless, the nanoscale charcoal passively mode-locked EDFL still shows the potential to generate picosecond pulses under a relatively low cavity gain. An appropriate cavity design can be used to compensate this defect-induced pulsewidth limitation and obtain a short pulsewidth.

  13. Carbon Nanotube Materials for Substrate Enhanced Control of Catalytic Activity

    SciTech Connect

    Heben, M.; Dillon, A. C.; Engtrakul, C.; Lee, S.-H.; Kelley, R. D.; Kini, A. M.

    2007-05-01

    Carbon SWNTs are attractive materials for supporting electrocatalysts. The properties of SWNTs are highly tunable and controlled by the nanotube's circumferential periodicity and their surface chemistry. These unique characteristics suggest that architectures constructed from these types of carbon support materials would exhibit interesting and useful properties. Here, we expect that the structure of the carbon nanotube support will play a major role in stabilizing metal electrocatalysts under extreme operating conditions and suppress both catalyst and support degradation. Furthermore, the chemical modification of the carbon nanotube surfaces can be expected to alter the interface between the catalyst and support, thus, enhancing the activity and utilization of the electrocatalysts. We plan to incorporate discrete reaction sites into the carbon nanotube lattice to create intimate electrical contacts with the catalyst particles to increase the metal catalyst activity and utilization. The work involves materials synthesis, design of electrode architectures on the nanoscale, control of the electronic, ionic, and mass fluxes, and use of advanced optical spectroscopy techniques.

  14. Adsorption of dichlorodifluoromethane, chlorodifluoromethane, and chloropentafluoroethane on activated carbon

    SciTech Connect

    Berlier, K.; Frere, M.; Bougard, J.

    1995-09-01

    The CFCs (chlorofluorocarbons) are used as working refrigerant fluids. Recent concerns of the effects of CFCs on the ozone layer requires the development of efficient recovery methods. One technique is to adsorb the fluids onto a porous medium such as silica gel or activated carbon. Isotherms and enthalpies of adsorption curves of dichlorodifluoromethane (R12), chlorodifluoromethane (R22), and chloropentafluoroethane (R115) on three different activated carbons have been obtained at 303 K and at pressures to 602 kPa.

  15. Carbon-Carbon Bond Cleavage in Activation of the Prodrug Nabumetone

    PubMed Central

    Varfaj, Fatbardha; Zulkifli, Siti N. A.; Park, Hyoung-Goo; Challinor, Victoria L.; De Voss, James J.

    2014-01-01

    Carbon-carbon bond cleavage reactions are catalyzed by, among others, lanosterol 14-demethylase (CYP51), cholesterol side-chain cleavage enzyme (CYP11), sterol 17β-lyase (CYP17), and aromatase (CYP19). Because of the high substrate specificities of these enzymes and the complex nature of their substrates, these reactions have been difficult to characterize. A CYP1A2-catalyzed carbon-carbon bond cleavage reaction is required for conversion of the prodrug nabumetone to its active form, 6-methoxy-2-naphthylacetic acid (6-MNA). Despite worldwide use of nabumetone as an anti-inflammatory agent, the mechanism of its carbon-carbon bond cleavage reaction remains obscure. With the help of authentic synthetic standards, we report here that the reaction involves 3-hydroxylation, carbon-carbon cleavage to the aldehyde, and oxidation of the aldehyde to the acid, all catalyzed by CYP1A2 or, less effectively, by other P450 enzymes. The data indicate that the carbon-carbon bond cleavage is mediated by the ferric peroxo anion rather than the ferryl species in the P450 catalytic cycle. CYP1A2 also catalyzes O-demethylation and alcohol to ketone transformations of nabumetone and its analogs. PMID:24584631

  16. Carbon-carbon bond cleavage in activation of the prodrug nabumetone.

    PubMed

    Varfaj, Fatbardha; Zulkifli, Siti N A; Park, Hyoung-Goo; Challinor, Victoria L; De Voss, James J; Ortiz de Montellano, Paul R

    2014-05-01

    Carbon-carbon bond cleavage reactions are catalyzed by, among others, lanosterol 14-demethylase (CYP51), cholesterol side-chain cleavage enzyme (CYP11), sterol 17β-lyase (CYP17), and aromatase (CYP19). Because of the high substrate specificities of these enzymes and the complex nature of their substrates, these reactions have been difficult to characterize. A CYP1A2-catalyzed carbon-carbon bond cleavage reaction is required for conversion of the prodrug nabumetone to its active form, 6-methoxy-2-naphthylacetic acid (6-MNA). Despite worldwide use of nabumetone as an anti-inflammatory agent, the mechanism of its carbon-carbon bond cleavage reaction remains obscure. With the help of authentic synthetic standards, we report here that the reaction involves 3-hydroxylation, carbon-carbon cleavage to the aldehyde, and oxidation of the aldehyde to the acid, all catalyzed by CYP1A2 or, less effectively, by other P450 enzymes. The data indicate that the carbon-carbon bond cleavage is mediated by the ferric peroxo anion rather than the ferryl species in the P450 catalytic cycle. CYP1A2 also catalyzes O-demethylation and alcohol to ketone transformations of nabumetone and its analogs.

  17. Adsorption of mono- and di-butyltin by a wheat charcoal: pH effects and modeling.

    PubMed

    Fang, Liping; Borggaard, Ole K; Christensen, Jan H; Holm, Peter E; Hansen, Hans Christian Bruun

    2012-10-01

    Understanding adsorption processes of butyltins (BTs) such as monobutyltin (MBT) and dibutyltin (DBT) by black carbons is important for the evaluation of BT exposure risks to organisms and humans. However, relevant knowledge is scarce. In this study, the acidity constants pK(a,1)=2.3, pK(a,2)=3.5 and pK(a,3)=5.9 for MBT and pK(a,1)=3.0 and pK(a,2)=5.1 for DBT are estimated via potentiometric titration. Additionally, adsorption isotherms of BTs to a wheat charcoal were determined. The adsorption behavior was observed to be pH-dependent due to BT speciation and the pH-dependent surface charge of the charcoal. MBT adsorption to the charcoal decreases with increasing pH from 4 to 8, while the highest adsorption occurs at pH 6 for DBT. Adsorption of the BTs is successfully described in the pH range of 3-10 by using a newly developed pH-dependent Dual Langmuir model. The model has the potential to predict the interaction of BT species with charcoal, which can contribute to the risk assessments of BTs in the environment.

  18. [HPLC combined with PCA technology for analysis of five gingerol compounds in different processing degrees of ginger charcoal].

    PubMed

    Yu, Jiang-yong; Chen, Qiu-fang; Lu, Guo-yong

    2015-11-01

    To establish a new method for simultaneously determining the content of five gingerol compounds in different processing degrees of ginger charcoal and PCA principal component analysis was conducted for analysis. Samples were analyzed on Ultimate TM XB-C18 column (4.6 mm x 250 mm, 5 μm) , with acetonitrile (A) -0.1% phosphoric acid solution (B) as mobile phase for gradient elution. Detection wavelength was set at 280 nm. The flow rate was 0.6 mL x min(-1) and the column temperature was 30 degrees C. The five compounds were separated well and showed good linearity (r ≥ 0.999 7) within the concentration ranges tested. The average value for recoveries was between 98.86% - 101.5% (RSD 1.4% - 2.9%). The contents of five compounds showed difference among different processing degrees of ginger charcoal. Zingiberone had the highest content in the standard carbon, and the content of gingerol was decreased as the deepening of processing degree. Different processing degrees of ginger charcoal were classified into three groups with PCA, and provided scientific basis for establishing the quality standards of ginger charcoal.

  19. Preparation and characterization of activated carbon from sugarcane bagasse by physical activation with CO2 gas

    NASA Astrophysics Data System (ADS)

    Bachrun, Sutrisno; AyuRizka, Noni; Annisa, SolichaHidayat; Arif, Hidayat

    2016-01-01

    A series of experiments have been conducted to study the effects of different carbonization temperatures (400, 600, and 800oC) on characteristics of porosity in activated carbon derived from carbonized sugarcane bagassechar at activation temperature of 800oC. The results showed that the activated carbon derived from high carbonized temperature of sugarcane bagassechars had higher BET surface area, total volume, micropore volume and yield as compared to the activated carbon derived from low carbonized temperature. The BET surface area, total volume and micropore volume of activated carbon prepared from sugarcane bagassechars obtained at 800oC of carbonized temperature and activation time of 120 min were 661.46m2/g, 0.2455cm3/g and 0.1989cm3/g, respectively. The high carbonization temperature (800oC) generated a highly microporous carbonwith a Type-I nitrogen adsorption isotherm, while the low carbonization temperature (400 and 600oC) generated a mesoporous one with an intermediate between types I and IInitrogen adsorption isotherm.

  20. A 45-year-old man with a lung mass and history of charcoal aspiration.

    PubMed

    Seder, David B; Christman, Robert A; Quinn, Michael O; Knauft, M Elizabeth

    2006-11-01

    A 45-year-old man was seen in consultation for evaluation of a spiculated right-lower-lobe mass that enlarged over 1 year. The patient had suffered accidental instillation of activated charcoal into the right lung via nasogastric tube 2 years prior to this consultation, with resultant respiratory failure, pneumonia, and pneumothorax. Biopsy of the mass showed anthracosis and granulomatous inflammation. A positron emission tomogram was strongly positive at the lesion, and right-lower-lobectomy with partial diaphragmatic resection was performed. On gross examination of the mass, a charcoal concretion was evident. Histologic examination showed intrinsic and surrounding granulomatous inflammation, but without tumor. The patient recovered uneventfully, and after 1 year had not experienced further complications.

  1. Waste polyvinylchloride derived pitch as a precursor to develop carbon fibers and activated carbon fibers.

    PubMed

    Qiao, W M; Yoon, S H; Mochida, I; Yang, J H

    2007-01-01

    Polyvinylchloride (PVC) was successfully recycled through the solvent extraction from waste pipe with an extraction yield of ca. 86%. The extracted PVC was pyrolyzed by a two-stage process (260 and 410 degrees C) to obtain free-chlorine PVC based pitch through an effective removal of chlorine from PVC during the heat-treatment. As-prepared pitch (softening point: 220 degrees C) was spun, stabilized, carbonized into carbon fibers (CFs), and further activated into activated carbon fibers (ACFs) in a flow of CO2. As-prepared CFs show comparable mechanical properties to commercial CFs, whose maximum tensile strength and modulus are 862 MPa and 62 GPa, respectively. The resultant ACFs exhibit a high surface area of 1200 m2/g, narrow pore size distribution and a low oxygen content of 3%. The study provides an effective insight to recycle PVC from waste PVC and develop a carbon precursor for high performance carbon materials such as CFs and ACFs.

  2. Water vapor adsorption on activated carbon preadsorbed with naphtalene.

    PubMed

    Zimny, T; Finqueneisel, G; Cossarutto, L; Weber, J V

    2005-05-01

    The adsorption of water vapor on a microporous activated carbon derived from the carbonization of coconut shell has been studied. Preadsorption of naphthalene was used as a tool to determine the location and the influence of the primary adsorbing centers within the porous structure of active carbon. The adsorption was studied in the pressure range p/p0=0-0.95 in a static water vapor system, allowing the investigation of both kinetic and equilibrium experimental data. Modeling of the isotherms using the modified equation of Do and Do was applied to determine the effect of preadsorption on the mechanism of adsorption.

  3. Activated carbon fiber composite material and method of making

    DOEpatents

    Burchell, Timothy D.; Weaver, Charles E.; Chilcoat, Bill R.; Derbyshire, Frank; Jagtoyen, Marit

    2000-01-01

    An activated carbon fiber composite for separation and purification, or catalytic processing of fluids is described. The activated composite comprises carbon fibers rigidly bonded to form an open, permeable, rigid monolith capable of being formed to near-net-shape. Separation and purification of gases are effected by means of a controlled pore structure that is developed in the carbon fibers contained in the composite. The open, permeable structure allows the free flow of gases through the monolith accompanied by high rates of adsorption. By modification of the pore structure and bulk density the composite can be rendered suitable for applications such as gas storage, catalysis, and liquid phase processing.

  4. Activated carbon fiber composite material and method of making

    DOEpatents

    Burchell, Timothy D.; Weaver, Charles E.; Chilcoat, Bill R.; Derbyshire, Frank; Jagtoyen, Marit

    2001-01-01

    An activated carbon fiber composite for separation and purification, or catalytic processing of fluids is described. The activated composite comprises carbon fibers rigidly bonded to form an open, permeable, rigid monolith capable of being formed to near-net-shape. Separation and purification of gases are effected by means of a controlled pore structure that is developed in the carbon fibers contained in the composite. The open, permeable structure allows the free flow of gases through the monolith accompanied by high rates of adsorption. By modification of the pore structure and bulk density the composite can be rendered suitable for applications such as gas storage, catalysis, and liquid phase processing.

  5. Differential Scanning Calorimetry (DSC) for the Analysis of Activated Carbon

    DTIC Science & Technology

    1991-10-01

    impregnation procedures . It is believed that Sutcliffe-Speakman is currently using coconut - shell as the carbon precursor (instead of the New Zealand coal...microstructure facilitate the adsorption process whereby all the undesirable materials are retained. For military deployment, the activated carbon is...AD-A245 899 H.P ’ l N dI dUenm / DIFFERENTIAL SCANNING CALORIMETRY (DSC) FOR THE ANALYSIS OF ACTIVATED CARBON (U) by S.H.C. a and L.E. Cameron DTIC x

  6. Production of activated carbon from rice husk Vietnam

    NASA Astrophysics Data System (ADS)

    Korobochkin, V. V.; Tu, N. V.; Hieu, N. M.

    2016-09-01

    This work is dedicated to the production of activated carbon from rice husk from Delta of the Red River in Viet Nam. At the first stage, carbonization of a rice husk was carried out to obtain material containing 43.1% carbon and 25 % silica with a specific surface area of 51.5 m2/g. After separating of silica (the second stage), the specific surface area of the product increased to 204 m2/g and the silica content decreased to 1.23% by weight as well. The most important stage in the formation of the porous structure of the material is the activation. The products with the high specific surface area in the range of 800-1345 m2/g were obtained by activation of carbonized product with water vapour or carbon dioxide at temperatures of 700 °C and 850 °C, with varying the flow rate of the activating agent and activation time. The best results were achieved by activation of carbon material with water vapour at the flow rate of 0.08 dm3/min per 500 g of material and the temperature of 850 °C.

  7. Activated Carbon Textile via Chemistry of Metal Extraction for Supercapacitors.

    PubMed

    Lam, Do Van; Jo, Kyungmin; Kim, Chang-Hyun; Kim, Jae-Hyun; Lee, Hak-Joo; Lee, Seung-Mo

    2016-12-27

    Carbothermic reduction in the chemistry of metal extraction (MO(s) + C(s) → M(s) + CO(g)) using carbon as a sacrificial agent has been used to smelt metals from diverse oxide ores since ancient times. Here, we paid attention to another aspect of the carbothermic reduction to prepare an activated carbon textile for high-rate-performance supercapacitors. On the basis of thermodynamic reducibility of metal oxides reported by Ellingham, we employed not carbon, but metal oxide as a sacrificial agent in order to prepare an activated carbon textile. We conformally coated ZnO on a bare cotton textile using atomic layer deposition, followed by pyrolysis at high temperature (C(s) + ZnO(s) → C'(s) + Zn(g) + CO(g)). We figured out that it leads to concurrent carbonization and activation in a chemical as well as mechanical way. Particularly, the combined effects of mechanical buckling and fracture that occurred between ZnO and cotton turned out to play an important role in carbonizing and activating the cotton textile, thereby significantly increasing surface area (nearly 10 times) compared with the cotton textile prepared without ZnO. The carbon textiles prepared by carbothermic reduction showed impressive combination properties of high power and energy densities (over 20-fold increase) together with high cyclic stability.

  8. Effects of CO 2 activation on porous structures of coconut shell-based activated carbons

    NASA Astrophysics Data System (ADS)

    Guo, Shenghui; Peng, Jinhui; Li, Wei; Yang, Kunbin; Zhang, Libo; Zhang, Shimin; Xia, Hongying

    2009-07-01

    In this paper, textural characterization of an activated carbon derived from carbonized coconut shell char obtained at carbonization temperature of 600 °C for 2 h by CO 2 activation was investigated. The effects of activation temperature, activation time and flow rate of CO 2 on the BET surface area, total volume, micropore volume and yield of activated carbons prepared were evaluated systematically. The results showed that: (i) enhancing activation temperature was favorable to the formation of pores, widening of pores and an increase in mesopores; (ii) increasing activation time was favorable to the formation of micropores and mesopores, and longer activation time would result in collapsing of pores; (iii) increasing flow rate of CO 2 was favorable to the reactions of all active sites and formation of pores, further increasing flow rate of CO 2 would lead carbon to burn out and was unfavorable to the formation of pores. The degree of surface roughness of activated carbon prepared was measured by the fractal dimension which was calculated by FHH (Frenkel-Halsey-Hill) theory. The fractal dimensions of activated carbons prepared were greater than 2.6, indicating the activated carbon samples prepared had very irregular structures, and agreed well with those of average micropore size.

  9. Comparison of toluene adsorption among granular activated carbon and different types of activated carbon fibers (ACFs).

    PubMed

    Balanay, Jo Anne G; Crawford, Shaun A; Lungu, Claudiu T

    2011-10-01

    Activated carbon fiber (ACF) has been demonstrated to be a good adsorbent for the removal of organic vapors in air. Some ACF has a comparable or larger surface area and higher adsorption capacity when compared with granular activated carbon (GAC) commonly used in respiratory protection devices. ACF is an attractive alternative adsorbent to GAC because of its ease of handling, light weight, and decreasing cost. ACF may offer the potential for short-term respiratory protection for first responders and emergency personnel. This study compares the critical bed depths and adsorption capacities for toluene among GAC and ACF of different forms and surface areas. GAC and ACF in cloth (ACFC) and felt (ACFF) forms were challenged in stainless steel chambers with a constant concentration of 500 ppm toluene via conditioned air at 25°C, 50% RH, and constant airflow (7 L/min). Breakthrough data were obtained for each adsorbent using gas chromatography with flame ionization detector. Surface areas of each adsorbent were determined using a physisorption analyzer. Results showed that the critical bed depth of GAC is 275% higher than the average of ACFC but is 55% lower than the average of ACFF. Adsorption capacity of GAC (with a nominal surface area of 1800 m(2)/g) at 50% breakthrough is 25% higher than the average of ACF with surface area of 1000 m(2)/g, while the rest of ACF with surface area of 1500 m(2)/g and higher have 40% higher adsorption capacities than GAC. ACFC with higher surface area has the smallest critical bed depth and highest adsorption capacity, which makes it a good adsorbent for thinner and lighter respirators. We concluded that ACF has great potential for application in respiratory protection considering its higher adsorption capacity and lower critical bed depth in addition to its advantages over GAC, particularly for ACF with higher surface area.

  10. Electroadsorption of Arsenic from natural water in granular activated carbon

    NASA Astrophysics Data System (ADS)

    Beralus, Jean-Mackson; Ruiz Rosas, Ramiro; Cazorla-Amoros, Diego; Morallon, Emilia

    2014-11-01

    The adsorption and electroadsorption of arsenic from a natural water has been studied in a filter-press electrochemical cell using a commercial granular activated carbon as adsorbent and Pt/Ti and graphite as electrodes. A significant reduction of the arsenic concentration is achieved when current is imposed between the electrodes, especially when the activated carbon was located in the vicinity of the anode. This enhancement can be explained in terms of the presence of electrostatic interactions between the polarized carbon surface and the arsenic ions, and changes in the distribution of most stable species of arsenic in solution due to As(III) to As(V) oxidation. In summary, electrochemical adsorption on a filter press cell can be used for enhancement the arsenic remediation with activated carbon in the treatment of a real groundwater.

  11. Use of charcoals and broiler litter biochar for removal of radioactive cesium (Cs-134 plus Cs-137) from contaminated water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Various charcoals (used in food processing and water treatment) and broiler litter biochar were examined for ability to adsorb water-soluble low-level radioactive cesium (ca. 200-250 Bq/kg) extracted from contaminated wheat bran. Among the materials tested, steam activated broiler litter biochar was...

  12. [Quickly enrichment of carbon in wastewater by activated sludge].

    PubMed

    Liu, Hong-Bo; Zhao, Fang; Wen, Xiang-Hua

    2011-10-01

    Pilot tests were carried out to investigate the absorption characteristics of the carbon source in urban wastewater by activated sludge and to analyze the carbon release from the carbon absorbed activated sludge in the settling process. The results indicated that carbon in wastewater could be quickly enriched by activated sludge. The absorption process of indissolvable organic matter could be finished as shortly as less than 10 min, while the absorption process of the dissolved organic matter was relatively slow and should consume up about 30 min. Moreover, carbon release was observed in the settling process of enriched sludge. In the period of 30-100 min, the release amount of total COD (TCOD) was 11.44 mg x g(-1), while in the period of 60-150 min, the release amount of dissolved COD (SCOD) was 6.24 mg x g(-1). Furthermore, based on the results of the bench-scale tests, a pilot-scale plant was built to investigate the absorption of carbon, nitrogen and phosphorus by activated sludge and the settleability of enriched sludge. The results indicated that under continuously operation mode, 60% of COD, 75% of TP and 10% of TN in the wastewater could be removed by the absorption of activated sludge, and the enriched sludge with SVI of 34.2 mL x g(-1) presented good settleability. Carbon enrichment by activated sludge could not only reclaim the carbon source in wastewater, but also reduce the loading of organic matter and give low C/N for the following nitrification unit and improving the nitrification efficiency.

  13. Composite electrodes of activated carbon derived from cassava peel and carbon nanotubes for supercapacitor applications

    NASA Astrophysics Data System (ADS)

    Taer, E.; Iwantono, Yulita, M.; Taslim, R.; Subagio, A.; Salomo, Deraman, M.

    2013-09-01

    In this paper, a composite electrode was prepared from a mixture of activated carbon derived from precarbonization of cassava peel (CP) and carbon nanotubes (CNTs). The activated carbon was produced by pyrolysis process using ZnCl2 as an activation agent. A N2 adsorption-desorption analysis for the sample indicated that the BET surface area of the activated carbon was 1336 m2 g-1. Difference percentage of CNTs of 0, 5, 10, 15 and 20% with 5% of PVDF binder were added into CP based activated carbon in order to fabricate the composite electrodes. The morphology and structure of the composite electrodes were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The SEM image observed that the distribution of CNTs was homogeneous between carbon particles and the XRD pattern shown the amorphous structure of the sample. The electrodes were fabricated for supercapacitor cells with 316L stainless steel as current collector and 1 M sulfuric acid as electrolyte. An electrochemical characterization was performed by using an electrochemical impedance spectroscopy (EIS) method using a Solatron 1286 instrument and the addition of CNTs revealed to improve the resistant and capacitive properties of supercapacitor cell.

  14. Adsorption uptake of synthetic organic chemicals by carbon nanotubes and activated carbons

    NASA Astrophysics Data System (ADS)

    Brooks, A. J.; Lim, Hyung-nam; Kilduff, James E.

    2012-07-01

    Carbon nanotubes (CNTs) have shown great promise as high performance materials for adsorbing priority pollutants from water and wastewater. This study compared uptake of two contaminants of interest in drinking water treatment (atrazine and trichloroethylene) by nine different types of carbonaceous adsorbents: three different types of single walled carbon nanotubes (SWNTs), three different sized multi-walled nanotubes (MWNTs), two granular activated carbons (GACs) and a powdered activated carbon (PAC). On a mass basis, the activated carbons exhibited the highest uptake, followed by SWNTs and MWNTs. However, metallic impurities in SWNTs and multiple walls in MWNTs contribute to adsorbent mass but do not contribute commensurate adsorption sites. Therefore, when uptake was normalized by purity (carbon content) and surface area (instead of mass), the isotherms collapsed and much of the CNT data was comparable to the activated carbons, indicating that these two characteristics drive much of the observed differences between activated carbons and CNT materials. For the limited data set here, the Raman D:G ratio as a measure of disordered non-nanotube graphitic components was not a good predictor of adsorption from solution. Uptake of atrazine by MWNTs having a range of lengths and diameters was comparable and their Freundlich isotherms were statistically similar, and we found no impact of solution pH on the adsorption of either atrazine or trichloroethylene in the range of naturally occurring surface water (pH = 5.7-8.3). Experiments were performed using a suite of model aromatic compounds having a range of π-electron energy to investigate the role of π-π electron donor-acceptor interactions on organic compound uptake by SWNTs. For the compounds studied, hydrophobic interactions were the dominant mechanism in the uptake by both SWNTs and activated carbon. However, comparing the uptake of naphthalene and phenanthrene by activated carbon and SWNTs, size exclusion effects

  15. Adsorption uptake of synthetic organic chemicals by carbon nanotubes and activated carbons.

    PubMed

    Brooks, A J; Lim, Hyung-nam; Kilduff, James E

    2012-07-27

    Carbon nanotubes (CNTs) have shown great promise as high performance materials for adsorbing priority pollutants from water and wastewater. This study compared uptake of two contaminants of interest in drinking water treatment (atrazine and trichloroethylene) by nine different types of carbonaceous adsorbents: three different types of single walled carbon nanotubes (SWNTs), three different sized multi-walled nanotubes (MWNTs), two granular activated carbons (GACs) and a powdered activated carbon (PAC). On a mass basis, the activated carbons exhibited the highest uptake, followed by SWNTs and MWNTs. However, metallic impurities in SWNTs and multiple walls in MWNTs contribute to adsorbent mass but do not contribute commensurate adsorption sites. Therefore, when uptake was normalized by purity (carbon content) and surface area (instead of mass), the isotherms collapsed and much of the CNT data was comparable to the activated carbons, indicating that these two characteristics drive much of the observed differences between activated carbons and CNT materials. For the limited data set here, the Raman D:G ratio as a measure of disordered non-nanotube graphitic components was not a good predictor of adsorption from solution. Uptake of atrazine by MWNTs having a range of lengths and diameters was comparable and their Freundlich isotherms were statistically similar, and we found no impact of solution pH on the adsorption of either atrazine or trichloroethylene in the range of naturally occurring surface water (pH = 5.7-8.3). Experiments were performed using a suite of model aromatic compounds having a range of π-electron energy to investigate the role of π-π electron donor-acceptor interactions on organic compound uptake by SWNTs. For the compounds studied, hydrophobic interactions were the dominant mechanism in the uptake by both SWNTs and activated carbon. However, comparing the uptake of naphthalene and phenanthrene by activated carbon and SWNTs, size exclusion effects

  16. Granular Activated Carbon Performance Capability and Availability.

    DTIC Science & Technology

    1983-06-01

    5-11 Notes: 1. As total nitrobodies 2. Combined with RDX 3. Includes dissolved air flotation, sand filter, and GAC 4. Can be achieved with moderate...RDX-HMX Water and Air Research Inc Feoruary 1976 Facility Newoort Army Aunition Plant 0-27 ater Quality Assessment for the Proposed RDX-HMX Water and... Air Research Inc February 1976 Facility, McAlester Naval munition Depot. Vol I 0-28 luorovin Granular Carbon Treatment FMC Corp/EPA 1792-6D" N 07 71

  17. Operationalizing measurement of forest degradation: Identification and quantification of charcoal production in tropical dry forests using very high resolution satellite imagery

    NASA Astrophysics Data System (ADS)

    Dons, K.; Smith-Hall, C.; Meilby, H.; Fensholt, R.

    2015-07-01

    Quantification of forest degradation in monitoring and reporting as well as in historic baselines is among the most challenging tasks in national REDD+ strategies. However, a recently introduced option is to base monitoring systems on subnational conditions such as prevalent degradation activities. In Tanzania, charcoal production is considered a major cause of forest degradation, but is challenging to quantify due to sub-canopy biomass loss, remote production sites and illegal trade. We studied two charcoal production sites in dry Miombo woodland representing open woodland conditions near human settlements and remote forest with nearly closed canopies. Supervised classification and adaptive thresholding were applied on a pansharpened QuickBird (QB) image to detect kiln burn marks (KBMs). Supervised classification showed reasonable detection accuracy in the remote forest site only, while adaptive thresholding was found acceptable at both locations. We used supervised classification and manual digitizing for KBM delineation and found acceptable delineation accuracy at both sites with RMSEs of 25-32% compared to ground measurements. Regression of charcoal production on KBM area delineated from QB resulted in R2s of 0.86-0.88 with cross-validation RMSE ranging from 2.22 to 2.29 Mg charcoal per kiln. This study demonstrates, how locally calibrated remote sensing techniques may be used to identify and delineate charcoal production sites for estimation of charcoal production and associated extraction of woody biomass.

  18. Adsorption Properties of Lignin-derived Activated Carbon Fibers (LACF)

    SciTech Connect

    Contescu, Cristian I.; Gallego, Nidia C.; Thibaud-Erkey, Catherine; Karra, Reddy

    2016-04-01

    The object of this CRADA project between Oak Ridge National Laboratory (ORNL) and United Technologies Research Center (UTRC) is the characterization of lignin-derived activated carbon fibers (LACF) and determination of their adsorption properties for volatile organic compounds (VOC). Carbon fibers from lignin raw materials were manufactured at Oak Ridge National Laboratory (ORNL) using the technology previously developed at ORNL. These fibers were physically activated at ORNL using various activation conditions, and their surface area and pore-size distribution were characterized by gas adsorption. Based on these properties, ORNL did down-select five differently activated LACF materials that were delivered to UTRC for measurement of VOC adsorption properties. UTRC used standard techniques based on breakthrough curves to measure and determine the adsorption properties of indoor air pollutants (IAP) - namely formaldehyde and carbon dioxide - and to verify the extent of saturated fiber regenerability by thermal treatments. The results are summarized as follows: (1) ORNL demonstrated that physical activation of lignin-derived carbon fibers can be tailored to obtain LACF with surface areas and pore size distributions matching the properties of activated carbon fibers obtained from more expensive, fossil-fuel precursors; (2) UTRC investigated the LACF potential for use in air cleaning applications currently pursued by UTRC, such as building ventilation, and demonstrated their regenerability for CO2 and formaldehyde, (3) Both partners agree that LACF have potential for possible use in air cleaning applications.

  19. Activated Carbon Composites for Air Separation

    SciTech Connect

    Contescu, Cristian I; Baker, Frederick S; Tsouris, Costas; McFarlane, Joanna

    2008-03-01

    In continuation of the development of composite materials for air separation based on molecular sieving properties and magnetic fields effects, several molecular sieve materials were tested in a flow system, and the effects of temperature, flow conditions, and magnetic fields were investigated. New carbon materials adsorbents, with and without pre-loaded super-paramagnetic nanoparticles of Fe3O4 were synthesized; all materials were packed in chromatographic type columns which were placed between the poles of a high intensity, water-cooled, magnet (1.5 Tesla). In order to verify the existence of magnetodesorption effect, separation tests were conducted by injecting controlled volumes of air in a flow of inert gas, while the magnetic field was switched on and off. Gas composition downstream the column was analyzed by gas chromatography and by mass spectrometry. Under the conditions employed, the tests confirmed that N2 - O2 separation occurred at various degrees, depending on material's intrinsic properties, temperature and flow rate. The effect of magnetic fields, reported previously for static conditions, was not confirmed in the flow system. The best separation was obtained for zeolite 13X at sub-ambient temperatures. Future directions for the project include evaluation of a combined system, comprising carbon and zeolite molecular sieves, and testing the effect of stronger magnetic fields produced by cryogenic magnets.

  20. FENTON-DRIVEN REGENERATION OF GRANULAR ACTIVATED CARBON: A TECHNOLOGY OVERVIEW

    EPA Science Inventory

    A Fenton-driven mechanism for regenerating spent granular activated carbon (GAC) involves the combined, synergistic use of two reliable and well established treatment technologies - adsorption onto activated carbon and Fenton oxidation. During carbon adsorption treatment, enviro...

  1. Biofuel intercropping effects on soil carbon and microbial activity.

    PubMed

    Strickland, Michael S; Leggett, Zakiya H; Sucre, Eric B; Bradford, Mark A

    2015-01-01

    Biofuels will help meet rising demands for energy and, ideally, limit climate change associated with carbon losses from the biosphere to atmosphere. Biofuel management must therefore maximize energy production and maintain ecosystem carbon stocks. Increasingly, there is interest in intercropping biofuels with other crops, partly because biofuel production on arable land might reduce availability and increase the price of food. One intercropping approach involves growing biofuel grasses in forest plantations. Grasses differ from trees in both their organic inputs to soils and microbial associations. These differences are associated with losses of soil carbon when grasses become abundant in forests. We investigated how intercropping switchgrass (Panicum virgalum), a major candidate for cellulosic biomass production, in loblolly pine (Pinus taeda) plantations affects soil carbon, nitrogen, and microbial dynamics. Our design involved four treatments: two pine management regimes where harvest residues (i.e., biomass) were left in place or removed, and two switchgrass regimes where the grass was grown with pine under the same two biomass scenarios (left or removed). Soil variables were measured in four 1-ha replicate plots in the first and second year following switchgrass planting. Under switchgrass intercropping, pools of mineralizable and particulate organic matter carbon were 42% and 33% lower, respectively. These declines translated into a 21% decrease in total soil carbon in the upper 15 cm of the soil profile, during early stand development. The switchgrass effect, however, was isolated to the interbed region where switchgrass is planted. In these regions, switchgrass-induced reductions in soil carbon pools with 29%, 43%, and 24% declines in mineralizable, particulate, and total soil carbon, respectively. Our results support the idea that grass inputs to forests can prime the activity of soil organic carbon degrading microbes, leading to net reductions in stocks

  2. Oxidation of activated carbon: application to vinegar decolorization.

    PubMed

    López, Francisco; Medina, Francisco; Prodanov, Marin; Güell, Carme

    2003-01-15

    This article reports studies on the feasibility of increasing the decoloring capacity of a granular activated carbon (GAC) by using oxidation with air at 350 degrees C to modify its surface activity and porosity. The GAC, obtained from olive stones, had a maximum decolorization capacity of 92% for doses of 20 g/l, while the maximum decolorization capacity of the modified granular activated carbon (MGAC) was about 96% at a dose of 10 g/l. The increase in decoloring capacity is thought to be due to an increase in mesopore area (from 129 to 340 m2/g) in the MGAC. The maximum decoloring values and the doses needed to attain them are very close to values obtained in previous studies using coconut shell powder-activated carbon (94 and 98% for red and white vinegar for a dose of 10 g/l, respectively).

  3. Activated carbon and tungsten oxide supported on activated carbon catalysts for toluene catalytic combustion.

    PubMed

    Alvarez-Merino, M A; Ribeiro, M F; Silva, J M; Carrasco-Marín, F; Maldonado-Hódar, F J

    2004-09-01

    We have used activated carbon (AC) prepared from almond shells as a support for tungsten oxide to develop a series of WOx/AC catalysts for the catalytic combustion of toluene. We conducted the reaction between 300 and 350 degrees C, using a flow of 500 ppm of toluene in air and space velocity (GHSV) in the range 4000-7000 h(-1). Results show that AC used as a support is an appropriate material for removing toluene from dilute streams. By decreasing the GHSV and increasing the reaction temperature AC becomes a specific catalyst for the total toluene oxidation (SCO2 = 100%), but in less favorable conditions CO appears as reaction product and toluene-derivative compounds are retained inside the pores. WOx/AC catalysts are more selective to CO2 than AC due to the strong acidity of this oxide; this behavior improves with increased metal loading and reaction temperature and contact time. The catalytic performance depends on the nonstoichiometric tungsten oxide obtained during the pretreatment. In comparison with other supports the WOx/AC catalysts present, at low reaction temperatures, higher activity and selectivity than WO, supported on SiO2, TiO2, Al2O3, or Y zeolite. This is due to the hydrophobic character of the AC surface which prevents the adsorption of water produced from toluene combustion thus avoiding the deactivation of the active centers. However, the use of WOx/AC system is always restricted by its gasification temperature (around 400 degrees C), which limits the ability to increase the conversion values by increasing reaction temperatures.

  4. Testing Iodized Activated Carbon Filters with Non-Radio Active Methyl Iodide.

    DTIC Science & Technology

    1980-05-30

    and 4314, 4315, and 4316 are labora- to y impregnations using KI, KIO 3, hexamethylenetetramine and a pH 10 phosphate buffer (11). The agreement...14, Columbia Activated Carbon 207A 8 x 16, Sutcliffe, Speakman Co. Ltd. BPL 8 x 20, Activated Carbon Division, Calgon Corp. KITEG II Nuclear Consulting Services, Inc. TEDA triethylenediamine HMTA hexamethylenetetramine 52

  5. Decolorization of Cheddar cheese whey by activated carbon.

    PubMed

    Zhang, Yue; Campbell, Rachel; Drake, MaryAnne; Zhong, Qixin

    2015-05-01

    Colored Cheddar whey is a source for whey protein recovery and is decolorized conventionally by bleaching, which affects whey protein quality. Two activated carbons were studied in the present work as physical means of removing annatto (norbixin) in Cheddar cheese whey. The color and residual norbixin content of Cheddar whey were reduced by a higher level of activated carbon at a higher temperature between 25 and 55°C and a longer time. Activated carbon applied at 40g/L for 2h at 30°C was more effective than bleaching by 500mg/L of hydrogen peroxide at 68°C. The lowered temperature in activated-carbon treatments had less effect on protein structure as investigated for fluorescence spectroscopy and volatile compounds, particularly oxidation products, based on gas chromatography-mass spectrometry. Activated carbon was also reusable, removing more than 50% norbixin even after 10 times of regeneration, which showed great potential for decolorizing cheese whey.

  6. Treatment of activated carbon to enhance catalytic activity for reduction of nitric oxide with ammonia

    SciTech Connect

    Ku, B.J.; Rhee, H.K. . Dept. of Chemical Engineering); Lee, J.K.; Park, D. )

    1994-11-01

    Catalytic activity of activated carbon treated with various techniques was examined in a fixed bed reactor for the reduction of nitric oxide with ammonia at 150 C. Activated carbon derived from coconut shell impregnated with an aqueous solution of ammonium sulfate, further treated with sulfuric acid, dried at 120 C, and then heated in an inert gas stream at 400 C, showed the highest catalytic activity within the range of experimental conditions. The enhancement of catalytic activity of modified activated carbon could be attributed to the increase in the amount of oxygen function groups which increased the adsorption site for ammonia. Catalytic activity of activated carbons depended on the surface area and the oxygen content as well.

  7. A General Methodology for Evaluation of Carbon Sequestration Activities and Carbon Credits

    SciTech Connect

    Klasson, KT

    2002-12-23

    A general methodology was developed for evaluation of carbon sequestration technologies. In this document, we provide a method that is quantitative, but is structured to give qualitative comparisons despite changes in detailed method parameters, i.e., it does not matter what ''grade'' a sequestration technology gets but a ''better'' technology should receive a better grade. To meet these objectives, we developed and elaborate on the following concepts: (1) All resources used in a sequestration activity should be reviewed by estimating the amount of greenhouse gas emissions for which they historically are responsible. We have done this by introducing a quantifier we term Full-Cycle Carbon Emissions, which is tied to the resource. (2) The future fate of sequestered carbon should be included in technology evaluations. We have addressed this by introducing a variable called Time-adjusted Value of Carbon Sequestration to weigh potential future releases of carbon, escaping the sequestered form. (3) The Figure of Merit of a sequestration technology should address the entire life-cycle of an activity. The figures of merit we have developed relate the investment made (carbon release during the construction phase) to the life-time sequestration capacity of the activity. To account for carbon flows that occur during different times of an activity we incorporate the Time Value of Carbon Flows. The methodology we have developed can be expanded to include financial, social, and long-term environmental aspects of a sequestration technology implementation. It does not rely on global atmospheric modeling efforts but is consistent with these efforts and could be combined with them.

  8. Trivalent chromium removal from wastewater using low cost activated carbon derived from agricultural waste material and activated carbon fabric cloth.

    PubMed

    Mohan, Dinesh; Singh, Kunwar P; Singh, Vinod K

    2006-07-31

    An efficient adsorption process is developed for the decontamination of trivalent chromium from tannery effluents. A low cost activated carbon (ATFAC) was prepared from coconut shell fibers (an agricultural waste), characterized and utilized for Cr(III) removal from water/wastewater. A commercially available activated carbon fabric cloth (ACF) was also studied for comparative evaluation. All the equilibrium and kinetic studies were conducted at different temperatures, particle size, pHs, and adsorbent doses in batch mode. The Langmuir and Freundlich isotherm models were applied. The Langmuir model best fit the equilibrium isotherm data. The maximum adsorption capacities of ATFAC and ACF at 25 degrees C are 12.2 and 39.56 mg/g, respectively. Cr(III) adsorption increased with an increase in temperature (10 degrees C: ATFAC--10.97 mg/g, ACF--36.05 mg/g; 40 degrees C: ATFAC--16.10 mg/g, ACF--40.29 mg/g). The kinetic studies were conducted to delineate the effect of temperature, initial adsorbate concentration, particle size of the adsorbent, and solid to liquid ratio. The adsorption of Cr(III) follows the pseudo-second-order rate kinetics. From kinetic studies various rate and thermodynamic parameters such as effective diffusion coefficient, activation energy and entropy of activation were evaluated. The sorption capacity of activated carbon (ATFAC) and activated carbon fabric cloth is comparable to many other adsorbents/carbons/biosorbents utilized for the removal of trivalent chromium from water/wastewater.

  9. Effects of charcoal kiln saunas (Jjimjilbang) on psychological states.

    PubMed

    Hayasaka, Shinya; Nakamura, Yosikazu; Kajii, Eiji; Ide, Masahiro; Shibata, Yosuke; Noda, Tatsuya; Murata, Chiyoe; Nagata, Katsutaro; Ojima, Toshiyuki

    2008-05-01

    This uncontrolled intervention study explored the effects of sauna bathing utilizing residual heat from charcoal kilns (charcoal kiln saunas) on psychological states. Forty-five volunteers (24 males and 21 females; mean age 51.9 years (S.D. 15.7) visiting a bamboo charcoal kiln in Japan participated in the study. They completed a shortened version of the Profile of Mood States (POMS) and State-Trait Anxiety Inventory (STAI) before and after charcoal kiln sauna bathing in order to determine mood and anxiety states. Six factors relating to mood were measured using the POMS: Tension-Anxiety, Depression-Dejection, Anger-Hostility, Vigor, Fatigue, and Confusion. The two anxiety concepts of state anxiety and trait anxiety were also measured. Changes in psychological states before and after sauna bathing were then determined. All mood scales and both manifest anxiety measures were improved after sauna bathing. Charcoal kiln sauna bathing appears to improve mood and decrease anxiety. It is a limitation of this study that this was a descriptive prospective and an uncontrolled intervention study. Further investigation of the improvement of trait anxiety is required.

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

    PubMed

    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.

  11. Synthesis of carbon fibers and activated carbon fibers from coal liquids

    SciTech Connect

    Fei, Y.Q.; Derbyshire, F.; Jagtoyen, M.; Kimber, G.

    1994-12-31

    The production and application of low-cost, general purpose carbon fibers and activated fibers are emerging technologies with exciting potential, although at present their cost is too high to find widespread use. Production and R and D have been limited and to data, only a small range of precursors has been studied: petroleum pitches, coal extracts and coal tar pitches. Both processing costs and the properties of the fiber products are dependent on the nature of the starting material. Commercial precursors have been limited to the pitches produced from high temperature pyrolysis or cracking processes and are similar in composition and molecular structure. Suitable coal-based precursors can be produced with a wide range of composition, and at moderate cost, by methods such as low temperature carbonization, solvent extraction, hydropyrolysis and mild coal liquefaction. It is of interest to investigate the synthesis of carbon fibers and activated carbon fibers from precursors of different origins to elucidate the influence of precursor materials on fiber formation and processing, and their structure and properties. It is also of practical importance to understand the relationships between the type of starting materials (for example, coals) and the processing methods, and the properties of fiber precursors that can be produced from them. In the present study, the authors describe the synthesis of carbon fibers and activated carbon fibers from the products of the first stage of coal liquefaction.

  12. Adsorption of aromatic organic contaminants by graphene nanosheets: comparison with carbon nanotubes and activated carbon.

    PubMed

    Apul, Onur Guven; Wang, Qiliang; Zhou, Yang; Karanfil, Tanju

    2013-03-15

    Adsorption of two synthetic organic compounds (SOCs; phenanthrene and biphenyl) by two pristine graphene nanosheets (GNS) and one graphene oxide (GO) was examined and compared with those of a coal base activated carbon (HD4000), a single-walled carbon nanotube (SWCNT), and a multi-walled carbon nanotube (MWCNT) in distilled and deionized water and in the presence of natural organic matter (NOM). Graphenes exhibited comparable or better adsorption capacities than carbon nanotubes (CNTs) and granular activated carbon (GAC) in the presence of NOM. The presence of NOM reduced the SOC uptake of all adsorbents. However, the impact of NOM on the SOC adsorption was smaller on graphenes than CNTs and activated carbons. Furthermore, the SOC with its flexible molecular structure was less impacted from NOM preloading than the SOC with planar and rigid molecular structure. The results indicated that graphenes can serve as alternative adsorbents for removing SOCs from water. However, they will also, if released to environment, adsorb organic contaminants influencing their fate and impact in the environment.

  13. Air gasification of rice husk in bubbling fluidized bed reactor with bed heating by conventional charcoal.

    PubMed

    Makwana, J P; Joshi, Asim Kumar; Athawale, Gaurav; Singh, Dharminder; Mohanty, Pravakar

    2015-02-01

    An experimental study of air gasification of rice husk was conducted in a bench-scale fluidized bed gasifier (FBG) having 210 mm diameter and 1600 mm height. Heating of sand bed material was performed using conventional charcoal fuel. Different operating conditions like bed temperature, feeding rate and equivalence ratio (ER) varied in the range of 750-850 °C, 25-31.3 kg/h, and 0.3-0.38, respectively. Flow rate of air was kept constant (37 m(3)/h) during FBG experiments. The carbon conversion efficiencies (CCE), cold gas efficiency, and thermal efficiency were evaluated, where maximum CCE was found as 91%. By increasing ER, the carbon conversion efficiency was decreased. Drastic reduction in electric consumption for initial heating of gasifier bed with charcoal compared to ceramic heater was ∼45%. Hence rice husk is found as a potential candidate to use directly (without any processing) in FBG as an alternative renewable energy source from agricultural field.

  14. High surface area activated carbon prepared from cassava peel by chemical activation.

    PubMed

    Sudaryanto, Y; Hartono, S B; Irawaty, W; Hindarso, H; Ismadji, S

    2006-03-01

    Cassava is one of the most important commodities in Indonesia, an agricultural country. Cassava is one of the primary foods in our country and usually used for traditional food, cake, etc. Cassava peel is an agricultural waste from the food and starch processing industries. In this study, this solid waste was used as the precursor for activated carbon preparation. The preparation process consisted of potassium hydroxide impregnation at different impregnation ratio followed by carbonization at 450-750 degrees C for 1-3 h. The results revealed that activation time gives no significant effect on the pore structure of activated carbon produced, however, the pore characteristic of carbon changes significantly with impregnation ratio and carbonization temperature. The maximum surface area and pore volume were obtained at impregnation ratio 5:2 and carbonization temperature 750 degrees C.

  15. The environmental applications of activated carbon/zeolite composite materials.

    PubMed

    Foo, K Y; Hameed, B H

    2011-02-17

    Over the past couple of years, the resurgence of placing an effective and sustainable amendment to combat against the auxiliary industrial entities, remains a highly contested agenda from a global point. With the renaissance of activated carbon, there has been a steadily growing interest in the research field. Recently, the adoption of zeolite composite, a prestigious advanced catalyst which formulates the enhancement of adsorption rate and hydrogen storage capability, has fore fronted to be a new growing branch in the scientific community. Confirming the assertion, this paper presents a state of art review of activated carbon/zeolite composite technology, its fundamental background studies, and environmental implications. Moreover, its major challenges together with the future expectation are summarized and discussed. Conclusively, the expanding of activated carbon/zeolite composite represents a potentially viable and powerful tool, leading to the plausible improvement of environmental preservation.

  16. Detoxification of pesticide waste via activated carbon adsorption process.

    PubMed

    Foo, K Y; Hameed, B H

    2010-03-15

    Concern about environmental protection has increased over the years from a global viewpoint. To date, the percolation of pesticide waste into the groundwater tables and aquifer systems remains an aesthetic issue towards the public health and food chain interference. With the renaissance of activated carbon, there has been a consistent growing interest in this research field. Confirming the assertion, this paper presents a state of art review of pesticide agrochemical practice, its fundamental characteristics, background studies and environmental implications. Moreover, the key advance of activated carbon adsorption, its major challenges together with the future expectation are summarized and discussed. Conclusively, the expanding of activated carbon adsorption represents a plausible and powerful circumstance, leading to the superior improvement of environmental preservation.

  17. Adsorption characteristics of acetone, chloroform and acetonitrile on sludge-derived adsorbent, commercial granular activated carbon and activated carbon fibers.

    PubMed

    Tsai, Jiun-Horng; Chiang, Hsiu-Mei; Huang, Guan-Yinag; Chiang, Hung-Lung

    2008-06-15

    The adsorption characteristics of chloroform, acetone, and acetonitrile on commercial activated carbon (C1), two types of activated carbon fibers (F1 and F2), and sludge adsorbent (S1) was investigated. The chloroform influent concentration ranged from 90 to 7800 ppm and the acetone concentration from 80 to 6900 ppm; the sequence of the adsorption capacity of chloroform and acetone on adsorbents was F2>F1 approximately C1 approximately S1. The adsorption capacity of acetonitrile ranged from 4 to 100 mg/g, corresponding to the influent range from 43 to 2700 ppm for C1, S1, and F1. The acetonitrile adsorption capacity of F2 was approximately 20% higher than that of the other adsorbents at temperatures<30 degrees C. The Freundlich equation fit the data better than the Langmuir and Dubinin-Radushkevich (D-R) equations. The adsorption rate of carbon fibers is higher than that of the other adsorbents due to their smaller fiber diameter and higher surface area. The micropore diffusion coefficient of VOC on activated carbon and sludge adsorbent was approximately 10(-4) cm2 s(-1). The diffusion coefficient of VOC on carbon fibers ranged from 10(-8) to 10(-7) cm2 s(-1). The small carbon fiber pore size corresponds to a smaller diffusion coefficient.

  18. Removal of benzocaine from water by filtration with activated carbon

    USGS Publications Warehouse

    Howe, G.E.; Bills, T.D.; Marking, L.L.

    1990-01-01

    Benzocaine is a promising candidate for registration with the U.S. Food and Drug Administration for use as an anesthetic in fish culture, management, and research. A method for the removal of benzocaine from hatchery effluents could speed registration of this drug by eliminating requirements for data on its residues, tolerances, detoxification, and environmental hazards. Carbon filtration effectively removes many organic compounds from water. This study tested the effectiveness of three types of activated carbon for removing benzocaine from water by column filtration under controlled laboratory conditions. An adsorptive capacity was calculated for each type of activated carbon. Filtrasorb 400 (12 x 40 mesh; U.S. standard sieve series) showed the greatest capacity for benzocaine adsorption (76.12 mg benzocaine/g carbon); Filtrasorb 300 (8 x 30 mesh) ranked next (31.93 mg/g); and Filtrasorb 816 (8 x 16 mesh) absorbed the least (1.0 mg/g). Increased adsorptive capacity was associated with smaller carbon particle size; however, smaller particle size also impeded column flow. Carbon filtration is a practical means for removing benzocaine from treated water.

  19. Improved granular activated carbon for the stabilization of wastewater PH

    SciTech Connect

    Farmer, R.W.; Dussert, B.W.; Kovacic, S.L.

    1996-12-31

    Laboratory studies have identified the cause of the pH rise, which occurs during water treatment with activated carbon, as an interaction between the naturally occurring anions and protons in the water and the carbon surface. The interaction can be described as an ion exchange type of phenomenon, in which the carbon surface sorbs the anions and corresponding hydronium ions from the water. These studies have shown that the anion sorption and resulting pH increase is independent of the raw material used for the activated carbon production, e.g. bituminous or subbituminous coal, peat, wood or coconut. Also, the pH excursions occur with virgin, reactivated, and acid washed granular carbons. Current pH control technologies focus on adjustment of the wastewater pH prior to discharge or recycle of the initial effluent water until the pH increase abates. However, improved water pH control options have been realized by altering the carbon surface through controlled oxidation rather than the water chemistry or extended preprocessing at the treatment site.

  20. Carbon Nanotubes Activate Limulus Amebocyte Lysate Coagulation by Interface Adsorption.

    PubMed

    Yang, Man; Nie, Xin; Meng, Jie; Liu, Jian; Sun, Zhiwei; Xu, Haiyan

    2017-03-15

    Limulus amebocyte lysate (LAL) assay is worldwide requested in the assessment of endotoxin contamination for biomaterials. As carbon nanotubes are one major nanomaterial with multiple potentials in biomedical application, here we investigate whether oxidized multiwalled carbon nanotubes (O-MWCNT) interferes the assessment by LAL assays. We showed that the endotoxin free O-MWCNT dispersing in aqueous solutions could activate both the gel-clotting and the end-point chromogenic LAL assay by converting coagulogen into coagulin through interfacial interactions between O-MWCNT and enzymes in the assays. In conclusion, the O-MWCNT could induce false positive results by activating the enzyme cascade of LAL.

  1. Removing lead in drinking water with activated carbon

    SciTech Connect

    Taylor, R.M.; Kuennen, R.W. )

    1994-02-01

    A point-of-use (POU) granular activated carbon (GAC) fixed bed adsorber (FBA) was evaluated for reduction of soluble and insoluble lead from drinking water. Some of the factors which affect lead removal by GAC were evaluated, such as carbon type, solution pH, and a limited amount of work on competitive interactions. The design criteria for lead reduction by a POU device are also addressed. Minicolumns were used to evaluate the capacity of carbon for lead under a variety of conditions. The importance of surface chemistry of the carbon and the relationship with the pH of the water for lead reduction was demonstrated. Results indicate that a properly designed POU-GAC-FBA can reduce lead in drinking water to below the EPA action level of 15 ppb while being tested under a variety of conditions as specified under the National Sanitation Foundation (NSF) International Standard 53 test protocol. 37 refs., 9 figs., 1 tab.

  2. Carbon-based supercapacitors produced by activation of graphene.

    PubMed

    Zhu, Yanwu; Murali, Shanthi; Stoller, Meryl D; Ganesh, K J; Cai, Weiwei; Ferreira, Paulo J; Pirkle, Adam; Wallace, Robert M; Cychosz, Katie A; Thommes, Matthias; Su, Dong; Stach, Eric A; Ruoff, Rodney S

    2011-06-24

    Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp(2)-bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.

  3. Carbon-based Supercapacitors Produced by Activation of Graphene

    SciTech Connect

    Y Zhu; S Murali; M Stoller; K Ganesh; W Cai; P Ferreira; A Pirkle; R Wallace; K Cychosz; et al.

    2011-12-31

    Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp{sup 2}-bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.

  4. Carbon-Based Supercapacitors Produced by Activation of Graphene

    SciTech Connect

    Zhu, Y.; Su, D.; Murali, S.; Stoller, M.D.; Ganesh, K.J.; Cai, W.; Ferreira, P.J.; Pirkle, A.; Wallace, R.M.; Cychosz, K.A., Thommes, M.; Stach, E.A.; Ruoff, R.S.

    2011-06-24

    Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp{sup 2}-bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.

  5. Tc-99 Adsorption on Selected Activated Carbons - Batch Testing Results

    SciTech Connect

    Mattigod, Shas V.; Wellman, Dawn M.; Golovich, Elizabeth C.; Cordova, Elsa A.; Smith, Ronald M.

    2010-12-01

    CH2M HILL Plateau Remediation Company (CHPRC) is currently developing a 200-West Area groundwater pump-and-treat system as the remedial action selected under the Comprehensive Environmental Response, Compensation, and Liability Act Record of Decision for Operable Unit (OU) 200-ZP-1. This report documents the results of treatability tests Pacific Northwest National Laboratory researchers conducted to quantify the ability of selected activated carbon products (or carbons) to adsorb technetium-99 (Tc-99) from 200-West Area groundwater. The Tc-99 adsorption performance of seven activated carbons (J177601 Calgon Fitrasorb 400, J177606 Siemens AC1230AWC, J177609 Carbon Resources CR-1240-AW, J177611 General Carbon GC20X50, J177612 Norit GAC830, J177613 Norit GAC830, and J177617 Nucon LW1230) were evaluated using water from well 299-W19-36. Four of the best performing carbons (J177606 Siemens AC1230AWC, J177609 Carbon Resources CR-1240-AW, J177611 General Carbon GC20X50, and J177613 Norit GAC830) were selected for batch isotherm testing. The batch isotherm tests on four of the selected carbons indicated that under lower nitrate concentration conditions (382 mg/L), Kd values ranged from 6,000 to 20,000 mL/g. In comparison. Under higher nitrate (750 mg/L) conditions, there was a measureable decrease in Tc-99 adsorption with Kd values ranging from 3,000 to 7,000 mL/g. The adsorption data fit both the Langmuir and the Freundlich equations. Supplemental tests were conducted using the two carbons that demonstrated the highest adsorption capacity to resolve the issue of the best fit isotherm. These tests indicated that Langmuir isotherms provided the best fit for Tc-99 adsorption under low nitrate concentration conditions. At the design basis concentration of Tc 0.865 µg/L(14,700 pCi/L), the predicted Kd values from using Langmuir isotherm constants were 5,980 mL/g and 6,870 mL/g for for the two carbons. These Kd values did not meet the target Kd value of 9,000 mL/g. Tests

  6. Arundo donax cane as a precursor for activated carbons preparation by phosphoric acid activation.

    PubMed

    Vernersson, T; Bonelli, P R; Cerrella, E G; Cukierman, A L

    2002-06-01

    Canes from Arundo donax, a herbaceous rapid-growing plant, were used as precursor for activated carbon preparation by phosphoric acid activation under a self-generated atmosphere. The influence of the carbonization temperature in the range 400-550 degrees C and of the weight ratio phosphoric acid to precursor (R = 1.5-2.5) on the developed porous structure of the resulting carbons was studied for 1 h of carbonization time. Surface properties of the activated carbons were dependent on a combined effect of the conditions employed. Carbons developed either with R = 1.5 over the range 400-500 degrees C, or with R = 2 at 500 degrees C exhibited surface areas of around 1100 m2/g, the latter conditions promoting a larger pore volume and enhanced mesoporous character. For both ratios, temperature above 500 degrees C led to reduction in porosity development. A similar effect was found for the highest ratio (R = 2.5) and 500 degrees C. The influence of carrying out the carbonization either for times shorter than 1 h or under flowing N2 was also examined at selected conditions (R = 2, 500 degrees C). Shorter times induced increase in the surface area (approximately 1300 m2/g), yielding carbons with smaller mean pore radius. Activated carbons obtained under flowing N2 possessed predominant microporous structures and larger ash contents than the samples derived in the self-generated atmosphere.

  7. Production Scale-Up or Activated Carbons for Ultracapacitors

    SciTech Connect

    Dr. Steven D. Dietz

    2007-01-10

    Transportation use accounts for 67% of the petroleum consumption in the US. Electric and hybrid vehicles are promising technologies for decreasing our dependence on petroleum, and this is the objective of the FreedomCAR & Vehicle Technologies Program. Inexpensive and efficient energy storage devices are needed for electric and hybrid vehicle to be economically viable, and ultracapacitors are a leading energy storage technology being investigated by the FreedomCAR program. The most important parameter in determining the power and energy density of a carbon-based ultracapacitor is the amount of surface area accessible to the electrolyte, which is primarily determined by the pore size distribution. The major problems with current carbons are that their pore size distribution is not optimized for liquid electrolytes and the best carbons are very expensive. TDA Research, Inc. (TDA) has developed methods to prepare porous carbons with tunable pore size distributions from inexpensive carbohydrate based precursors. The use of low-cost feedstocks and processing steps greatly lowers the production costs. During this project with the assistance of Maxwell Technologies, we found that an impurity was limiting the performance of our carbon and the major impurity found was sulfur. A new carbon with low sulfur content was made and found that the performance of the carbon was greatly improved. We also scaled-up the process to pre-production levels and we are currently able to produce 0.25 tons/year of activated carbon. We could easily double this amount by purchasing a second rotary kiln. More importantly, we are working with MeadWestvaco on a Joint Development Agreement to scale-up the process to produce hundreds of tons of high quality, inexpensive carbon per year based on our processes.

  8. Atypical Hydrogen Uptake on Chemically Activated, Ultramicroporous Carbon

    SciTech Connect

    Bhat, Vinay V; Contescu, Cristian I; Gallego, Nidia C; Baker, Frederick S

    2010-01-01

    Hydrogen adsorption at near-ambient temperatures on ultramicroporous carbon (UMC), derived through secondary chemical activation from a wood-based activated carbon was studied using volumetric and gravimetric methods. The results showed that physisorption is accompanied by a process of different nature that causes slow uptake at high pressures and hysteresis on desorption. In combination, this results in unusually high levels of hydrogen uptake at near-ambient temperatures and pressures (e.g. up to 0.8 wt % at 25 oC and 2 MPa). The heat of adsorption corresponding to the slow process leading to high uptake (17 20 kJ/mol) is higher than usually reported for carbon materials, but the adsorption kinetics is slow, and the isotherms exhibit pronounced hysteresis. These unusual properties were attributed to contributions from polarization-enhanced physisorption caused by traces of alkali metals residual from chemical activation. The results support the hypothesis that polarization-induced physisorption in high surface area carbons modified with traces of alkali metal ions is an alternate route for increasing the hydrogen storage capacity of carbon adsorbents.

  9. Effects of organic carbon sequestration strategies on soil enzymatic activities

    NASA Astrophysics Data System (ADS)

    Puglisi, E.; Suciu, N.; Botteri, L.; Ferrari, T.; Coppolecchia, D.; Trevisan, M.; Piccolo, A.

    2009-04-01

    Greenhouse gases emissions can be counterbalanced with proper agronomical strategies aimed at sequestering carbon in soils. These strategies must be tested not only for their ability in reducing carbon dioxide emissions, but also for their impact on soil quality: enzymatic activities are related to main soil ecological quality, and can be used as early and sensitive indicators of alteration events. Three different strategies for soil carbon sequestration were studied: minimum tillage, protection of biodegradable organic fraction by compost amendment and oxidative polimerization of soil organic matter catalyzed by biometic porfirins. All strategies were compared with a traditional agricultural management based on tillage and mineral fertilization. Experiments were carried out in three Italian soils from different pedo-climatic regions located respectively in Piacenza, Turin and Naples and cultivated with maize or wheat. Soil samples were taken for three consecutive years after harvest and analyzed for their content in phosphates, ß-glucosidase, urease and invertase. An alteration index based on these enzymatic activities levels was applied as well. The biomimetic porfirin application didn't cause changes in enzymatic activities compared to the control at any treatment or location. Enzymatic activities were generally higher in the minimum tillage and compost treatment, while differences between location and date of samplings were limited. Application of the soil alteration index based on enzymatic activities showed that soils treated with compost or subjected to minimum tillage generally have a higher biological quality. The work confirms the environmental sustainability of the carbon sequestering agronomical practices studied.

  10. Enhancing methane production during the anaerobic digestion of crude glycerol using Japanese cedar charcoal.

    PubMed

    Watanabe, Ryoya; Tada, Chika; Baba, Yasunori; Fukuda, Yasuhiro; Nakai, Yutaka

    2013-12-01

    The use of Japanese cedar charcoal as a support material for microbial attachment could enhance methane production during anaerobic digestion of crude glycerol and wastewater sludge. Methane yield from a charcoal-containing reactor was approximately 1.6 times higher than that from a reactor without charcoal, and methane production was stable over 50 days when the loading rate was 2.17 g chemical oxygen demand (COD) L(-1) d(-1). Examination of microbial communities on the charcoal revealed the presence of Uncultured Desulfovibrio sp. clone V29 and Pelobacter seleniigenes, known as 1,3-propandiol degraders. Hydrogenotrophic methanogens were also detected in the archaeal community on the charcoal. Methanosaeta, Methanoregula, and Methanocellus were present in the charcoal-containing reactor. The concentration of propionate in the charcoal-containing reactor was also lower than that in the control reactor. These results suggest that propionate degradation was enhanced by the consumption of hydrogen by hydrogenotrophic methanogens on the charcoal.

  11. Charcoal's physical properties are key to understanding its environmental behavior

    NASA Astrophysics Data System (ADS)

    Masiello, Caroline; Brewer, Catherine; Dugan, Brandon; Liu, Zuolin; Gonnermann, Helge; Zygourakis, Kyriacos; Davies, Christian; Panzacchi, Pietro; Gao, Xiaodong; Pyle, Lacey

    2014-05-01

    Charcoal is a highly porous, low density material whose physical properties play a key role in its soil behavior and its environmental fate. In considering biochar, some of its most sought-after environmental effects are a result of its physical characteristics, not its chemical or biological properties. For example, the ability of biochar to retain soil water is widely attributed to its porosity. However, charcoal physical properties are so poorly understood that they are sometimes not characterized at all in the current literature. Here we outline a suite of basic physical properties of charcoal and the likely environmental effects of their variations, with a focus on the interactions between charcoal and water. The most basic physical property of charcoal, its particle size, likely plays a role in its ability to alter the rate of drainage in soils. Particle morphology is also relevant, affecting how particles of soil and char can pack together. Bulk densities of charcoal and soil mixtures can be used to generate a simple estimate of the efficiency of char-soil packing. Charcoal density is an additionally important property and can be measured in a number of ways. Density almost certainly controls the tendency of chars to sink or float, and to erode or remain on the land surface. However, charcoal density can vary by almost a factor of 10 depending on the measurement technique used. We discuss two simple techniques available for measuring char density and the value of information provided by each approach. Finally, we report a simple, fast technique to measure total char porosity, including all pores from nanometers to 10s of micrometers in size. Porosity is at least one of the key controls on the ability of biochar to improve plant-available water, and techniques to measure it have previously been limited to the smallest fraction of pores (N2 sorption) or have required expensive, hazardous procedures (Hg porosimetry). We show that char porosity varies primarily

  12. Can Charcoal Provide Information About Fire Effects and Fire Severity?

    NASA Astrophysics Data System (ADS)

    Belcher, Claire; Hudpsith, Victoria; Doerr, Stefan; Santin, Cristina

    2016-04-01

    Building an understanding of the impact of a wildfire is critical to the management of ecosystems. Aspects of fire severity such as the amount of soil heating, can relate to post-fire ecosystem recovery. Yet, there is no quantitative measure of this in current post-burn fire severity assessments, which are mostly qualitative ground-based visual assessments of organic matter loss, and as such can be subjective and variable between ecosystems. In order to develop a unifying fire severity assessment we explore the use of charcoal produced during a wildfire, as a tool. Charcoal has been suggested to retain some information about the nature of the fire in which it was created and one such physical property of charcoal that can be measured post-fire is its ability to reflect light when studied under oil using reflectance microscopy. The amount of light reflected varies between charcoals and is thought to be explained by the differential ordering of graphite-like phases within the char however, to what aspects of a fire's nature this alteration pertains is unknown. We have explored the formation of charcoal reflectance in 1) laboratory-based experiments using an iCone calorimeter and in 2) experimental forest scale and natural wildland fires occurring in Canada in spring 2015. In our laboratory experiments we assessed the formation and evolution of charcoal reflectance during pre-ignition heating, peak fire intensity through to the end of flaming and the transition to oxidative/smoldering heating regimes. In the prescribed and natural wildland fires we positioned the same woods used in our laboratory experiments, rigged with thermocouples in the path of oncoming fires in order to assess the resulting charcoal reflectance in response to the heating regime imposed by the fire on the samples. In this presentation we will outline our approach, findings and discuss the potential for charcoal reflectance to provide a tool in post-fire assessments seeking to determine levels of

  13. Evaluation of charcoal sorbents for helium cryopumping in fusion reactors

    SciTech Connect

    Tobin, A.G.; Sedgley, D.W.; Batzer, T.H.; Call, W.R.

    1987-01-01

    Improved methods for cryopumping helium were developed for application to fusion reactors where high helium generation rates are expected. In this study, small coconut charcoal granules were utilized as the sorbent, and braze alloys and low temperature curing cements were used as the bonding agents for attachment to a copper support structure. Problems of scale-up of the bonding agent to a 40 cm diam panel were also investigated. Our results indicate that acceptable helium pumping performance of braze bonded and cement bonded charcoals can be achieved over the range of operating conditions expected in fusion reactors.

  14. Nitrogen-Containing Carbon Nanotube Synthesized from Polymelem and Activated Carbon Derived from Polymer Blend

    NASA Astrophysics Data System (ADS)

    Qin, Nan

    Polymelem possesses a polymeric structure of heptazine (C6N 7) rings connected by amine bridges and our study has demonstrated that it is a promising precursor for the synthesis of nitrogen-containing carbon materials. Nitrogen-containing carbon nanotube (NCNT) was produced by pyrolyzing polymelem as a dual source of carbon and nitrogen with Raney nickel in a high pressure stainless steel cell. Activated carbon was produced from poly(ether ether ketone)/poly(ether imide) (PEEK/PEI blend) and incorporated with polymelem to enhance the hydrogen adsorption. Polymelem was successfully synthesized by pyrolyzing melamine at 450--650 °C and its structure was elucidated by 13C solid state NMR, FTIR, and XRD. The molecular weight determined by a novel LDI MS equipped with a LIFT mode illuminated that polymelem has both linear and cyclic connectivity with a degree of polymerization of 2--5 depending on the synthesis temperature. The decomposition products of polymelem were determined to be cyanoamide, dicyanoamide, and tricyanoamine. Tricyanoamine is the smallest carbon nitride molecule and has been experimentally confirmed for the first time in this study. When polymelem was decomposed in the presence of Raney nickel, homogenous NCNT with nitrogen content of ˜ 4--19 atom% was produced. A mechanism based on a detail analysis of the TEM images at different growth stages proposed that the NCNT propagated via a tip-growth mechanism originating at the nano-domains within the Raney nickel, and was accompanied with the aggregation of the nickel catalysts. Such NCNT exhibited a cup-stack wall structure paired with a compartmental feature. The nitrogen content, tube diameter and wall thickness greatly depended on synthesis conditions. The activated carbon derived from PEEK/PEI blend demonstrated a surface area up to ˜3000 m2/g, and average pore size of < 20 A. Such activated carbon exhibited a hydrogen storage capacity of up to 6.47 wt% at 40 bar, 77 K. The activated carbon has

  15. Activity of catalase adsorbed to carbon nanotubes: effects of carbon nanotube surface properties.

    PubMed

    Zhang, Chengdong; Luo, Shuiming; Chen, Wei

    2013-09-15

    Nanomaterials have been studied widely as the supporting materials for enzyme immobilization. However, the interactions between enzymes and carbon nanotubes (CNT) with different morphologies and surface functionalities may vary, hence influencing activities of the immobilized enzyme. To date how the adsorption mechanisms affect the activities of immobilized enzyme is not well understood. In this study the adsorption of catalase (CAT) on pristine single-walled carbon nanotubes (SWNT), oxidized single-walled carbon nanotubes (O-SWNT), and multi-walled carbon nanotubes (MWNT) was investigated. The adsorbed enzyme activities decreased in the order of O-SWNT>SWNT>MWNT. Fourier transforms infrared spectroscopy (FTIR) and circular dichrois (CD) analyses reveal more significant loss of α-helix and β-sheet of MWNT-adsorbed than SWNT-adsorbed CAT. The difference in enzyme activities between MWNT-adsorbed and SWNT-adsorbed CAT indicates that the curvature of surface plays an important role in the activity of immobilized enzyme. Interestingly, an increase of β-sheet content was observed for CAT adsorbed to O-SWNT. This is likely because as opposed to SWNT and MWNT, O-SWNT binds CAT largely via hydrogen bonding and such interaction allows the CAT molecule to maintain the rigidity of enzyme structure and thus the biological function.

  16. Asphalt-derived high surface area activated porous carbons for carbon dioxide capture.

    PubMed

    Jalilov, Almaz S; Ruan, Gedeng; Hwang, Chih-Chau; Schipper, Desmond E; Tour, Josiah J; Li, Yilun; Fei, Huilong; Samuel, Errol L G; Tour, James M

    2015-01-21

    Research activity toward the development of new sorbents for carbon dioxide (CO2) capture have been increasing quickly. Despite the variety of existing materials with high surface areas and high CO2 uptake performances, the cost of the materials remains a dominant factor in slowing their industrial applications. Here we report preparation and CO2 uptake performance of microporous carbon materials synthesized from asphalt, a very inexpensive carbon source. Carbonization of asphalt with potassium hydroxide (KOH) at high temperatures (>600 °C) yields porous carbon materials (A-PC) with high surface areas of up to 2780 m(2) g(-1) and high CO2 uptake performance of 21 mmol g(-1) or 93 wt % at 30 bar and 25 °C. Furthermore, nitrogen doping and reduction with hydrogen yields active N-doped materials (A-NPC and A-rNPC) containing up to 9.3% nitrogen, making them nucleophilic porous carbons with further increase in the Brunauer-Emmett-Teller (BET) surface areas up to 2860 m(2) g(-1) for A-NPC and CO2 uptake to 26 mmol g(-1) or 114 wt % at 30 bar and 25 °C for A-rNPC. This is the highest reported CO2 uptake among the family of the activated porous carbonaceous materials. Thus, the porous carbon materials from asphalt have excellent properties for reversibly capturing CO2 at the well-head during the extraction of natural gas, a naturally occurring high pressure source of CO2. Through a pressure swing sorption process, when the asphalt-derived material is returned to 1 bar, the CO2 is released, thereby rendering a reversible capture medium that is highly efficient yet very inexpensive.

  17. Perspectives on Raman spectroscopy of graphene-based systems: from the perfect two-dimensional surface to charcoal.

    PubMed

    Jorio, Ado; Cançado, Luiz Gustavo

    2012-11-28

    Raman spectroscopy has been already established as a powerful tool for characterizing the different types of carbon nanostructures, ranging from the highly ordered two-dimensional graphene and one-dimensional nanotubes, down to disordered materials, like nanographite and charcoal. Here we focus on the recent advances of Raman spectroscopy within carbon nanoscience. We discuss in situ nano-manipulation and Raman imaging for addressing controlled perturbations; multi-technique work for the development of nanometrology; crossing the diffraction limit with near-field optics for high resolution imaging. Finally, the applications of Raman spectroscopy in cross-referenced fields, like biotechnology and soil science, are discussed.

  18. 40 CFR 60.1820 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... activated carbon? 60.1820 Section 60.1820 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... activated carbon? If your municipal waste combustion unit uses activated carbon to control dioxins/furans or mercury emissions, you must meet three requirements: (a) Select a carbon injection system...

  19. 40 CFR 60.1820 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... activated carbon? 60.1820 Section 60.1820 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... activated carbon? If your municipal waste combustion unit uses activated carbon to control dioxins/furans or mercury emissions, you must meet three requirements: (a) Select a carbon injection system...

  20. 40 CFR 60.1820 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... activated carbon? 60.1820 Section 60.1820 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... activated carbon? If your municipal waste combustion unit uses activated carbon to control dioxins/furans or mercury emissions, you must meet three requirements: (a) Select a carbon injection system...

  1. 40 CFR 60.1820 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... activated carbon? 60.1820 Section 60.1820 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... activated carbon? If your municipal waste combustion unit uses activated carbon to control dioxins/furans or mercury emissions, you must meet three requirements: (a) Select a carbon injection system...

  2. 40 CFR 60.1820 - How do I monitor the injection rate of activated carbon?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... activated carbon? 60.1820 Section 60.1820 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... activated carbon? If your municipal waste combustion unit uses activated carbon to control dioxins/furans or mercury emissions, you must meet three requirements: (a) Select a carbon injection system...

  3. [Preparation and optimum process of walnut peel activated carbon by zinc chloride as activating agent].

    PubMed

    Liu, Xiao-hong; Wang, Xing-wei; Zhao, Bo; Lü, Jun-fang; Kang, Ni-na; Zhang, Yao-jun

    2014-12-01

    Walnut peel as raw material, zinc chloride was used as activating agent for preparation walnut peel activated carbon in the muffle furnace in this experiment, using orthogonal design. Yield, the specific surface area and iodine number of walnut peel activated carbon were determined at all designed experimental conditions and the optimum technological condition of preparation was obtained. By analysis of aperture, infrared spectra and the content of acidic group in surface with Boehm, walnut peel activated carbon of prepared at the optimum condition was characterized. The results showed the optimum technological parameters of preparation: activation temperature (600 °C), activation time (1 h), the concentration of zinc chloride (50%), the particle size (60 mesh). The specific surface area of walnut peel activated carbon obtained at optimum condition was mounting to 1258.05 m2 · g(-1), the ratio of medium porous 32.18%. Therefore, walnut peel can be used in the preparation of the high-quality activated carbon of large surface area. Agricultural wastes, as walnut peel, not only were implemented recycle, but also didn't make any pollution. Meanwhile, a cheap adsorbent was provided and it was of great significance to open a new source of activated carbon.

  4. Physicochemical effect of activation temperature on the sorption properties of pine shell activated carbon.

    PubMed

    Wasim, Agha Arslan; Khan, Muhammad Nasiruddin

    2017-03-01

    Activated carbons produced from a variety of raw materials are normally selective towards a narrow range of pollutants present in wastewater. This study focuses on shifting the selectivity of activated carbon from inorganic to organic pollutants using