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Sample records for chemical wood pulp

  1. 40 CFR 430.80 - Applicability; description of the non-wood chemical pulp subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-wood chemical pulp subcategory. 430.80 Section 430.80 Protection of Environment ENVIRONMENTAL... CATEGORY Non-Wood Chemical Pulp Subcategory § 430.80 Applicability; description of the non-wood chemical... production of pulp and paper at non-wood chemical pulp mills. This subcategory includes, but is not...

  2. 40 CFR 430.80 - Applicability; description of the non-wood chemical pulp subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-wood chemical pulp subcategory. 430.80 Section 430.80 Protection of Environment ENVIRONMENTAL... CATEGORY Non-Wood Chemical Pulp Subcategory § 430.80 Applicability; description of the non-wood chemical... production of pulp and paper at non-wood chemical pulp mills. This subcategory includes, but is not...

  3. 40 CFR 430.80 - Applicability; description of the non-wood chemical pulp subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-wood chemical pulp subcategory. 430.80 Section 430.80 Protection of Environment ENVIRONMENTAL... POINT SOURCE CATEGORY Non-Wood Chemical Pulp Subcategory § 430.80 Applicability; description of the non-wood chemical pulp subcategory. The provisions of this subpart are applicable to discharges...

  4. 40 CFR 430.80 - Applicability; description of the non-wood chemical pulp subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-wood chemical pulp subcategory. 430.80 Section 430.80 Protection of Environment ENVIRONMENTAL... POINT SOURCE CATEGORY Non-Wood Chemical Pulp Subcategory § 430.80 Applicability; description of the non-wood chemical pulp subcategory. The provisions of this subpart are applicable to discharges...

  5. 40 CFR 430.80 - Applicability; description of the non-wood chemical pulp subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-wood chemical pulp subcategory. 430.80 Section 430.80 Protection of Environment ENVIRONMENTAL... POINT SOURCE CATEGORY Non-Wood Chemical Pulp Subcategory § 430.80 Applicability; description of the non-wood chemical pulp subcategory. The provisions of this subpart are applicable to discharges...

  6. 46 CFR 148.325 - Wood chips; wood pellets; wood pulp pellets.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Wood chips; wood pellets; wood pulp pellets. 148.325... § 148.325 Wood chips; wood pellets; wood pulp pellets. (a) This part applies to wood chips and wood pulp... cargo hold. (b) No person may enter a cargo hold containing wood chips, wood pellets, or wood...

  7. 46 CFR 148.325 - Wood chips; wood pellets; wood pulp pellets.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Wood chips; wood pellets; wood pulp pellets. 148.325... § 148.325 Wood chips; wood pellets; wood pulp pellets. (a) This part applies to wood chips and wood pulp... cargo hold. (b) No person may enter a cargo hold containing wood chips, wood pellets, or wood...

  8. 46 CFR 148.325 - Wood chips; wood pellets; wood pulp pellets.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Wood chips; wood pellets; wood pulp pellets. 148.325... § 148.325 Wood chips; wood pellets; wood pulp pellets. (a) This part applies to wood chips and wood pulp... cargo hold. (b) No person may enter a cargo hold containing wood chips, wood pellets, or wood...

  9. 46 CFR 148.325 - Wood chips; wood pellets; wood pulp pellets.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Wood chips; wood pellets; wood pulp pellets. 148.325... § 148.325 Wood chips; wood pellets; wood pulp pellets. (a) This part applies to wood chips and wood pulp... cargo hold. (b) No person may enter a cargo hold containing wood chips, wood pellets, or wood...

  10. Wood Pulp Digetster Wall Corrosion Investigation

    SciTech Connect

    Giles, GE

    2003-09-18

    The modeling of the flow in a wood pulp digester is but one component of the investigation of the corrosion of digesters. This report describes the development of a Near-Wall-Model (NWM) that is intended to couple with a CFD model that determines the flow, heat, and chemical species transport and reaction within the bulk flow of a digester. Lubrication theory approximations were chosen from which to develop a model that could determine the flow conditions within a thin layer near the vessel wall using information from the interior conditions provided by a CFD calculation of the complete digester. The other conditions will be determined by coupled solutions of the wood chip, heat, and chemical species transport and chemical reactions. The NWM was to couple with a digester performance code in an iterative fashion to provide more detailed information about the conditions within the NW region. Process Simulations, Ltd (PSL) is developing the digester performance code. This more detailed (and perhaps more accurate) information from the NWM was to provide an estimate of the conditions that could aggravate the corrosion at the wall. It is intended that this combined tool (NWM-PSL) could be used to understand conditions at/near the wall in order to develop methods to reduce the corrosion. However, development and testing of the NWM flow model took longer than anticipated and the other developments (energy and species transport, chemical reactions and linking with the PSL code) were not completed. The development and testing of the NWM are described in this report. In addition, the investigation of the potential effects of a clear layer (layer reduced in concentration of wood chips) near the wall is reported in Appendix D. The existence of a clear layer was found to enhance the flow near the wall.

  11. Chemical composition and pulping of date palm rachis and Posidonia oceanica--a comparison with other wood and non-wood fibre sources.

    PubMed

    Khiari, R; Mhenni, M F; Belgacem, M N; Mauret, E

    2010-01-01

    In the present paper, the valorisation of two residues: Posidonia oceanica and date palm rachis was investigated. First, their chemical composition was studied and showed that they present amounts of holocellulose, lignin and cellulose similar to those encountered in softwood and hardwood. Extractives in different solvents and ash contents are relatively high. Moreover, ash composition assessment showed that silicon is the major component (17.7%) for P. oceanica. The high ash quantity and the low DP (about 370) may be considered as serious disadvantages of P. oceanica, in the pulping and papermaking context. Oppositely, the properties of rachis date palm and those of the ensuing pulp, obtained from a classical soda-anthraquinone cooking, demonstrated the suitability of this agricultural by-product for papermaking. Preliminary tests conducted on unrefined pulp suspensions and handsheets from date palm rachis in terms of freeness, Water Retention Value and mechanical properties allowed confirming the good quality of date palm rachis fibres. PMID:19766481

  12. Electron treatment of wood pulp for the viscose process

    NASA Astrophysics Data System (ADS)

    Stepanik, T. M.; Ewing, D. E.; Whitehouse, R.

    2000-03-01

    Electron processing is currently being evaluated by several viscose producers for integration into their process. The viscose industry converts dissolving wood pulp into products such as staple fibre, filament, cord, film, packaging, and non-edible sausage casings. These materials are used in the clothing, drapery, hygiene, automobile, food, and packaging industries. Viscose producers are facing increasingly high production costs and stringent environmental regulations that have forced some plants to close. Electron treatment of wood pulp can significantly reduce the amounts of chemicals used for producing viscose and the production of hazardous pollutants. Acsion Industries has worked with companies worldwide to demonstrate the benefits of using electron treated pulp for producing viscose (rayon). This paper describes the viscose process, the benefits of using electron treatment in the viscose process, and Acsion's efforts in developing this technology.

  13. Synthesis of SiC nanorods from bleached wood pulp

    SciTech Connect

    Shin, Yongsoon; Wang, Chong M.; Samuels, William D.; Exarhos, Gregory J.

    2007-05-01

    Unbleached and bleached soft wood pulps have been used as templates and carbon precursors to produce SiC nanorods. Hydrolyzed tetraethylorthosilicate (TEOS), Silicic acid was infiltrated into the pulps followed by a carbothermal reduction to form SiC nanorods at 1400oC in Ar. Residual carbon formed along with SiC was removed by gasification at 700oC in air. The SiC materials prepared from unbleached pulp were non-uniform SiC with a thick SiO2 coating, while the SiC nanorods prepared from the bleached pulp were uniform and straight with dimensions of 250 nm in diameter and 5.0 mm long. The formation of uniform camelback structure of SiC in the reaction between silica and bleached pulp is attributed to more silica deposited in the amorphous region of cellulose.

  14. Method for improving separation of carbohydrates from wood pulping and wood or biomass hydrolysis liquors

    DOEpatents

    Griffith, William Louis; Compere, Alicia Lucille; Leitten, Jr., Carl Frederick

    2010-04-20

    A method for separating carbohydrates from pulping liquors includes the steps of providing a wood pulping or wood or biomass hydrolysis pulping liquor having lignin therein, and mixing the liquor with an acid or a gas which forms an acid upon contact with water to initiate precipitation of carbohydrate to begin formation of a precipitate. During precipitation, at least one long chain carboxylated carbohydrate and at least one cationic polymer, such as a polyamine or polyimine are added, wherein the precipitate aggregates into larger precipitate structures. Carbohydrate gel precipitates are then selectively removed from the larger precipitate structures. The method process yields both a carbohydrate precipitate and a high purity lignin.

  15. High Speed Photography Of Wood Pulping In A Disc Refiner

    NASA Astrophysics Data System (ADS)

    Atack, D.; Clayton, D. L.; Quinn, A. E.; Stationwala, M. I.

    1985-02-01

    Some of the mechanisms involved in the reduction of wood chips to papermaking pulp in a commercial disc refiner have been determined by high speed photography. Flow patterns of pulp through the refiner, including an unexpected recirculation pattern, have been recorded. Cine-photography was also employed to show how wood chips are transported by a ribbon screw feeder into the refiner. Some aspects of photographing in a hostile environment are described. The following salient observations have been made during these studies. Chips and dilution water fall to the base of the feeder housing and are fed along it to the refiner eye, where the chips are reduced to coarse pulp. This coarse pulp proceeds through the breaker bars into the refining zone. Some pulp in the inner part of the refining zone flows back to the breaker bars along grooves of the stationary plates, giving rise to considerable recirculation. Pulp in the outer part of the refining zone moves radially outwards. For a short fraction of its passage through the refiner, most of the fibrous material is constrained to move in the direction of rotation of the moving plates. Some of this material is stapled momentarily in a tangential orientation across the bars of both sets of plates. The immobilized fibres are then subjected to the refining action between the relatively moving bars before being disgorged into the adjacent grooves.

  16. Wood pulp characterization by a novel photoacoustic sensor

    NASA Astrophysics Data System (ADS)

    Niemi, Jan; Löfqvist, Torbjörn

    2012-08-01

    In this paper we introduce a novel photoacoustic sensing technique that captures a photoacoustic signal excited by a laser light pulse after the light has propagated through a turbid medium. Simultaneously, the ultrasonic sound wave is captured after it has propagated through the same turbid medium. By combining the two signals, more information on the investigated medium can be obtained. Applications can be found in the pulp and paper industry where monitoring wood pulp compositions is of interest. Depending on its origin, pulp suspension contains different compositions of fibres and fibre fragments (fines). Poor control of the pulp composition leads to an unstable process that compromises the production, quality and energy efficiency in the pulp mill. The result shows the feasibility of the photoacoustic sensor in monitoring the mass fractions of fibres and fines in a pulp suspension. The first received echo, corresponding to the light interaction with the sample, showed a stronger correlation to the fines mass fraction compared to fibre mass fraction. The second echo, corresponding to the sound wave interaction with the sample, showed a much stronger correlation to fibre mass fraction than to fines mass fraction. Hence, it is proposed that by combining these two echoes, more information about the pulp suspension could be extracted than from any other sensor built on a single sensing principle.

  17. Materials interactions relevant to the pulp, paper, and wood industries

    SciTech Connect

    Caulfield, D.F. . Forest Products Lab.); Passaretti, J.D. ); Sobezynski, S.F. . Office of Industrial Programs)

    1990-01-01

    The symposium demonstrated that wood and paper, although often overlooked as materials by the materials research community, provide a vibrant field for materials research. Of special interest to materials researchers is the interaction between pulp, paper and wood with other materials. This paper is divided into categories that constituted the themes for the five sessions of the symposium: wood/polymer composites, fiber/fiber interactions, fiber/water interactions, papermaking and coating processes, and surface interactions: fillers and pigments. One recurrent problem discussed throughout the symposium was the need to discover new ways to promote intimate and effective interactions between the highly polar surfaces of wood, paper and cellulose and materials whose surfaces might tend to be non-polar in nature.

  18. Ultrasonic Sensor to Characterize Wood Pulp During Refining

    SciTech Connect

    Greenwood, Margaret S.; Panetta, Paul D.; Bond, Leonard J.; McCaw, M. W.

    2006-12-22

    A novel sensor concept has been developed for measuring the consistency, the degree of refining, the water retention value (WRV), and the consistency of wood pulp during the refining process. The measurement time is less than 5 minutes and the sensor can operate in a slip-stream of the process line or as an at-line instrument. The consistency is obtained from a calibration, in which the attenuation of ultrasound through the pulp suspension is measured as a function of the solids weight percentage. The degree of refining and the WRV are determined from settling measurements. The settling of a pulp suspension (consistency less than 0.5 Wt%) is observed, after the mixer that keeps the pulp uniformly distributed is turned off. The attenuation of ultrasound as a function of time is recorded and these data show a peak, after a certain delay, defined as the “peak time.” The degree of refining increases with the peak time, as demonstrated by measuring pulp samples with different degrees of refining. The WRV can be determined using the relative peak time, defined as the ratio T2/T1, where T1 is an initial value of the peak time and T2 is the value after additional refining. This method offers an additional WRV test for the industry, because the freeness test is not specific for the WRV.

  19. Potential of hot water extraction of birch wood to produce high-purity dissolving pulp after alkaline pulping.

    PubMed

    Borrega, Marc; Tolonen, Lasse K; Bardot, Fanny; Testova, Lidia; Sixta, Herbert

    2013-05-01

    The potential of hot water extraction of birch wood to produce highly purified dissolving pulp in a subsequent soda-anthraquinone pulping process was evaluated. After intermediate extraction intensities, pulps with low xylan content (3-5%) and high cellulose yield were successfully produced. Increasing extraction intensity further decreased the xylan content in pulp. However, below a xylan content of 3%, the cellulose yield dramatically decreased. This is believed to be due to cleavage of glycosidic bonds in cellulose during severe hot water extractions, followed by peeling reactions during alkaline pulping. Addition of sodium borohydride as well as increased anthraquinone concentration in the pulping liquor increased the cellulose yield, but had no clear effects on pulp purity and viscosity. The low intrinsic viscosity of pulps produced after severe extraction intensities and soda-anthraquinone pulping corresponded to the viscosity at the leveling-off degree of polymerization, suggesting that nearly all amorphous cellulose had been degraded. PMID:23260272

  20. Possibility of Using Wood Pulp in the Preparation of Cement Composites

    NASA Astrophysics Data System (ADS)

    Kidalova, Lucia; Stevulova, Nadezda; Geffert, Anton

    2014-06-01

    Sustainable building materials are based on the use of renewable materials instead of non-renewable. Large group of renewable materials composes of plant fibres having high tensile strength are used as fillers into building material with reinforcement function of composite. This study aimed to establish the mechanical and physical properties of cement composites with organic fillers, such as wood pulp. Wood pulp cellulose is very interesting material as reinforcement in cement which contributes to a reduction of pollutants. Varying the producing technology (wood pulp and cement ratio in mixture) it is possible to obtain composites with density from 940 to 1260 kgm-3 and with compressive strength from 1.02 to 5.44 MPa after 28 days of hardening. Based on the experimental results, cement composites with using unbleached wood pulp reach higher values than composites based on bleached wood pulp. Volume ratio of unbleached wood pulp in composites influences water absorbability of cement composites

  1. Continuous on-line measurement of lignin concentration in wood pulp

    SciTech Connect

    Jeffers, L.A.; Roman, G.W.

    1994-06-01

    We are working toward the development of an instrument for the continuous, on-line measurement of the lignin concentration in wood pulp. The instrument is based on laser induced fluorescence of the wood pulp and is to be used as a primary sensor for both feedback control of the pulping and feedforward control of bleaching. We report here the results of a series of laboratory tests that characterized the fluorescence properties of wood pulp and demonstrated a correlation between various fluorescence functions and the Kappa number of the pulps as determined by TAPPI Procedure T236.

  2. Ultrasonic sensor to characterize wood pulp during refining.

    PubMed

    Greenwood, M S; Panetta, P D; Bond, L J; McCaw, M W

    2006-12-22

    A novel sensor concept has been developed for measuring the degree of refining, the water retention value (WRV), and the weight percentage of wood pulp during the refining process. The measurement time is less than 5 min and the sensor can operate in a slip-stream of the process line or as an at-line instrument. The degree of refining and the WRV are determined from settling measurements. The settling of a pulp suspension (with a weight percentage less than 0.5 wt%) is observed, after the mixer, which keeps the pulp uniformly distributed, is turned off. The attenuation of ultrasound as a function of time is recorded and these data show a peak at a time designated as the "peak time." The peak time T increases with the degree of refining, as demonstrated by measuring pulp samples with known degrees of refining. The WRV can be determined using the relative peak time, defined as the ratio T(2)/T(1), where T(1) is an initial peak time and T(2) is the value after additional refining. This method offers an alternative WRV test for the industry to the current time-consuming method. PMID:16920173

  3. Chemicals from wood by organic-solvent delignification. Final report

    SciTech Connect

    April, G.C.; Nayak, R.G.; Daley, P.L.; Jabali, F.; Meraab, J.

    1983-10-01

    Studies undertaken to evaluate the effectiveness of organic-solvent delignification of sweet gum and southern yellow pine wood are reported. Batch delignification investigations were conducted using aqueous n-butanol, ethanol, and phenol solutions at temperatures between 135C and 205C. Temperature, catalyst type and concentration, wood type, and treatment method were some of the variables considered. Southern yellow pine pretreatment studies were performed using water, and the use of semi-batch pulping methods was evaluated. Both delignification and pulp loss were described by first-order kinetics, and results generally agreed with those reported in the literature. Soluble pulp rate constants agreed closely with the bulk delignification rate constants, indicating the probability of a common mechanism describing the hydrolysis of wood during the initial periods. Second-step rate constants indicated a significantly slower delignification process. Finally, findings indicate that high temperatures are needed to effectively remove lignin from softwoods when no chemical additives are used.

  4. Effect of biological treatment on pulp mill effluent chemical characteristics

    SciTech Connect

    LaFleur, L.E.; Bousquet, T.E.; Cook, D.L.

    1995-12-31

    In the last 20 years, detailed characterizations of pulping and bleaching wastewaters have been performed identifying a large variety of chemical by-products. However, formation in the process does not translate into discharge into the environment. Pulp and paper mills in the US almost uniformly practice biological treatment. Although initially implemented for BOD removal, biological treatment is also responsible for removing or reducing many classes of compounds. This paper will briefly review the literature related to the characterization of process versus biologically treated wastewaters. Data on specific removal efficiencies for these compounds will be summarized and discussed. mechanisms of removal (such as biological degradation or transformation, sorption or volatilization) for selected compounds will be discussed. Examples of mass emission rates for volatiles, resin and fatty ,acids, plant sterols, mono-terpenes (and related compounds), chlorinated and non-chlorinated phenolics and other cellulose degradation products will be presented. Factors influencing the discharge rates such as pulping and bleaching practices, geographical location of the mills and wood species being pulped will be discussed.

  5. Method and apparatus for assaying wood pulp fibers

    DOEpatents

    Gustafson, Richard; Callis, James B.; Mathews, Jeffrey D.; Robinson, John; Bruckner, Carsten A.; Suvamakich, Kuntinee

    2009-05-26

    Paper pulp is added to a stain solution. The stain solution and pulp fibers are mixed to form a slurry. Samples are removed from the slurry and are admixed with dilution water and a bleach. Then, the fibers are moved into a flow cell where they are subjected to a light source adapted to stimulate fluorescence from the stained pulp fiber. Before the fiber slurry enters the flow cell it is mixed with a dilution water of bleach to reduce background fluorescence. The fluorescent light is collimated and directed through a dichroic filter onto a fluorescence splitting dichroic filter.

  6. 'KLEBSIELLA' DENSITIES IN WATERS RECEIVING WOOD PULP EFFLUENTS

    EPA Science Inventory

    Surface waters receiving pulp mill effluents were examined for the presence of total coliforms, fecal coliforms, and Salmonella species. Fecal coliforms were biochemically identified as belonging to the Escherichia, Klebsiella or Enterobacter genera. Sixty percent of the isolates...

  7. Control of Atmospheric Emissions in the Wood Pulping Industry, Volume 3.

    ERIC Educational Resources Information Center

    Hendrickson, E. R.; And Others

    Volume 3 contains chapters 9 through 13 of the final report on the control of atmospheric emissions in the wood pulping industry. These chapters deal with the following topics: sampling and analytical techniques; on-going research related to reduction of emissions; research and development recommendations; current industry investment and operating…

  8. REMOVAL OF WOOD-DERIVED TOXICS FROM PULPING AND BLEACHING WASTES

    EPA Science Inventory

    Wood-derived compounds known to possess toxicity toward fish and to be present in pulp mill effluents include resin and unsaturated fatty acids, their chlorinated analogs, chlorinated guaiacols, and epoxystearic acid. The objective of this investigation has been to assess the ext...

  9. [Study on dioxin emission for typical non-wood pulp making in China].

    PubMed

    Wang, Zhi-Fang; Ding, Qiong; Wang, Kai-Xiang; Wu, Chang-Min; Qu, Yun-Huan; Zhao, Xiao-Dong

    2012-02-01

    Based on the requirement of National Implementation Plan for the Stockholm Convention on Persistent Organic Pollutants (NIP), six industries including pulp and paper industry have been set as the priority key sectors to implement the best available technology and best environmental practice (BAT/BEP) within a specific time for UPOPs reduction. Non-wood pulping has always played important role in virgin pulp production in China, its elemental chlorinated bleaching process has been confirmed as main source of Dioxin emission for the sector. As the signature party of Stockholm Convention and long time existing country of non-wood pulping, identification of Dioxin emission situation is significant importance to China to committee the obligation of Stockholm Convention. The Dioxin concentrations in outflow water of bamboo, straw, reed, and bagasse pulping processes (chlorination alkaline extraction hypochlorite, CEH) are 41.8 pg x L(-1), 72.7 pg x L(-1), 7.46 pg x L(-1), and 19.7 pg x L(-1) respectively, which are all around the national waste water discharge standard (30 pg x L(-1)). But relevant data will easily exceed national standard while the limitation of unit water consumption for pulp making is decreased. So the application of best available techniques/best environmental practices (BAT/BEP) is very necessary to improve relevant mills up to the above standard, and proceed the sector meeting the national and international requirements for Dioxin emission. At the same time, the text calculates emission factors on bamboo, straw, reed and bagasse pulp making process through whole process monitoring, which will provide meaningful reference for increasing relevant factors in UNEP Toolkit. PMID:22509599

  10. On-line measurement of lignin in wood pulp by color shift of fluorescence

    DOEpatents

    Jeffers, Larry A.; Malito, Michael L.

    1996-01-01

    Lignin concentrations from wood pulp samples are measured by applying an excitation light at a selected wavelength to the samples in order to cause the lignin to emit fluorescence. A spectral distribution of the fluorescence emission is then determined. The lignin concentration is then calculated based on the spectral distribution signal. The spectral distribution is quantified by either a wavelength centroid method or a band ratio method.

  11. On-line measurement of lignin in wood pulp by color shift of fluorescence

    DOEpatents

    Jeffers, L.A.; Malito, M.L.

    1996-01-23

    Lignin concentrations from wood pulp samples are measured by applying an excitation light at a selected wavelength to the samples in order to cause the lignin to emit fluorescence. A spectral distribution of the fluorescence emission is then determined. The lignin concentration is then calculated based on the spectral distribution signal. The spectral distribution is quantified by either a wavelength centroid method or a band ratio method. 6 figs.

  12. Formation and emission of PCDD/Fs in Chinese non-wood pulp and paper mills.

    PubMed

    Wang, Xueli; Ni, Yuwen; Zhang, Haijun; Zhang, Xueping; Chen, Jiping

    2012-11-01

    Chlorine bleaching is still practiced by non-wood pulp and paper mills in China, resulting in considerable formation and emission of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). We investigate the distribution of PCDD/Fs in different papermaking processes and dioxin emissions at six typical Chinese non-wood pulp and paper mills. Raw materials for papermaking included reed, wheat straw, bamboo, and sugar cane bagasse. The formation and emission of PCDD/Fs varied strikingly according to bleaching processes and raw materials. Elemental chlorine bleaching promoted the formation of tetra- to octa-CDDs and 2,3,7,8-TCDF, while hypochlorite bleaching only gave rise to a significant increase of 2,3,7,8-TCDF. Bleaching with elemental chlorine and hypochlorite increased 2,3,7,8-TCDF 0.9-42.5 and 0.3-4.1 times, respectively. Most of the 2,3,7,8-TCDF formed at hypochlorite bleaching stage was partitioned into the effluent, which indicated that hypochlorite bleaching was also an important emission source of dioxins. The removal of PCDD/Fs occurred visibly during alkaline digestion, alkaline extraction, and hydrogen peroxide bleaching. Furthermore, the annual emission of PCDD/Fs from Chinese non-wood pulp and paper mills was evaluated. PMID:23067332

  13. Transformation and removal of wood extractives from pulp mill sludge using wet oxidation and thermal hydrolysis.

    PubMed

    Baroutian, Saeid; Robinson, Murray; Smit, Anne-Marie; Wijeyekoon, Suren; Gapes, Daniel

    2013-10-01

    In order to remove wood extractive compounds from pulp mill sludge and thereby enhancing anaerobic digestibility, samples were subjected to either oxidative hydrothermal treatment (wet oxidation) or non-oxidative hydrothermal treatment (thermal hydrolysis). Treatments were carried out at 220 °C with initial pressure of 20 bar. More than 90% destruction of extractive compounds was observed after 20 min of wet oxidation. Wet oxidation eliminated 95.7% of phenolics, 98.6% fatty acids, 99.8% resin acids and 100% of phytosterols in 120 min. Acetic acid concentration increased by approximately 2 g/l after 120 min of wet oxidation. This has potential for rendering sludge more amenable to anaerobic digestion. In contrast thermal hydrolysis was found to be ineffective in degrading extractive compounds. Wet oxidation is considered to be an effective process for removal of recalcitrant and inhibitive compounds through hydrothermal pre-treatment of pulp mill sludge. PMID:23948266

  14. Pulp and paper mills

    SciTech Connect

    Not Available

    1980-10-14

    The various hazards present in the many steps used in the production of products from pulp and paper mills were reviewed and discussed. The biological effects of 43 chemical, physical and dust hazards were detailed in the report. Dust hazards included exposures to wood dust, mold and bagasse dusts and fibrogenic dusts. Physical hazards included high heat and humidity, and noise. Raw materials and chemical intermediates discussed included calcium-oxide (1305788), magnesium-oxide (1309484), pulping liquors, sodium-hydroxide (1310732), sulfate, sulfites, sulfides, sulfur (7704349) and sulfuric-acid (7664939). Pulp bleaching agents were discussed along with papermaking additives, contaminants and/or byproducts, and pulping or combustion effluents. Sampling and analytical techniques for physical and chemical hazards were discussed. Engineering controls for hazards in pulp and paper mills were reviewed. OSHA regulations governing pulp and paper mills were evaluated.

  15. WOOD STOVE EMISSIONS: PARTICLE SIZE AND CHEMICAL COMPOSITION

    EPA Science Inventory

    The report summarizes wood stove particle size and chemical composition data gathered to date. [NOTE: In 1995, EPA estimated that residential wood combustion (RWC), including fireplaces, accounted for a significant fraction of national particulate matter with aerodynamic diameter...

  16. A survey of present levels of radiocesium in Swedish pulp mill liquors and the implications for wood radiocesium transfer factors.

    PubMed

    Ravila, A; Holm, E

    1998-10-27

    Assessments of the impact from radioactive fallout on the pulp industry and the accumulation processes for radionuclides in such industries, using wood and water as primary raw materials, have been conducted in previous studies. Hitherto, there is a general lack of data on present levels of radioactivity in pulp mill liquors apart from the few mills studied by Nilsson (1992); Ravila and Holm (1992); Manjón et al. (1996); Krosshavn et al. (1997). A survey was therefore initiated to describe and compare the present activity levels in pulp mill liquors from various mill locations in Sweden. The 137Cs activity in pulp mill liquors were compared with the mill location and the deposition pattern of the Chernobyl fallout and nuclear weapons fallout. The large input of wood (approx. 2500 m3 day-1) to an average Nordic Kraft mill and the relatively long-term retention time for radiocesium in the Kraft mill recovery cycle enables representative sampling of substances directly related to the activity concentration in wood. PMID:9851069

  17. Effects of low dosage electron irradiation on draft pulping and papermaking properties of southern pine wood

    SciTech Connect

    Nelson, D.S.

    1986-01-01

    Changes in draft pulping and papermaking properties caused by irradiation of air dry and never dried southern pine wood with sterilizing doses of electron radiation were investigated. Delignification rates were not measurably altered by irradiation. Carbohydrate yields were reduced by ca. 1% (on OD wood) at 0.1 Mrad, 1.5% at 9.2 Mrad, and 2-2.5% at 0.4 Mrad. Losses of this magnitude were shown to be consistent with reported radiochemical yields of alkali sensitive moeities in cellulose when the direct effect of irradiation is magnified by alkaline peeling. Beating times required to reach target freeness levels were reduced by approximately 5% at 0.1 Mrad, 10% at 0.2 Mrad, and 15% at 0.4 Mrad. Irradiation did not change the optical brightness of paper handsheets. Paper tensile and bursting strengths were also not affected, but tear resistance was reduced by 5-10% at 0.1 Mrad, 10-15% at 0.2 Mrad, and 20-25% at 0.4 Mrad. Reduced tear resistance was attributed to lower interfiber bond strength, a consequence of greater peeling losses. Retention of tensile and bursting strengths indicates that fiber tensile strength was not impaired, and that interfiber bonding remained strong enough to load most fibers to the breaking point.

  18. POZONE technology to bleach pulp

    SciTech Connect

    Wang, H.; Shi, Y.; Le, L.; Wang, S.M.; Wei, J.; Chang, S.G.

    1997-09-01

    Currently, there has been a move in the pulp and paper industry to reduce or eliminate chlorine-based bleaching due to environmental concerns. The POZONE process, a chemical means of ozone production, has been used to bleach wood pulp. The brightness, Kappa number, and viscosity of wood pulp subjected to POZONE treatment have been determined. Brightness increases of up to 44 points and Kappa number decreases of as much as 22 points have been achieved. Promise for effective industrial application has been demonstrated.

  19. Fermentation and chemical treatment of pulp and paper mill sludge

    DOEpatents

    Lee, Yoon Y; Wang, Wei; Kang, Li

    2014-12-02

    A method of chemically treating partially de-ashed pulp and/or paper mill sludge to obtain products of value comprising taking a sample of primary sludge from a Kraft paper mill process, partially de-ashing the primary sludge by physical means, and further treating the primary sludge to obtain the products of value, including further treating the resulting sludge and using the resulting sludge as a substrate to produce cellulase in an efficient manner using the resulting sludge as the only carbon source and mixtures of inorganic salts as the primary nitrogen source, and including further treating the resulting sludge and using the resulting sludge to produce ethanol.

  20. Butanol production from wood pulping hydrolysate in an integrated fermentation-gas stripping process

    SciTech Connect

    Lu, CC; Dong, J; Yang, ST

    2013-09-01

    Wood pulping hydrolysate (WPH) containing mainly xylose and glucose as a potential substrate for acetone-butanol-ethanol (ABE) fermentation was studied. Due to the inhibitors present in the hydrolysate, several dilution levels and detoxification treatments, including overliming, activated charcoal adsorption, and resin adsorption, were evaluated for their effectiveness in relieving the inhibition on fermentation. Detoxification using resin and evaporation was found to be the most effective method in reducing the toxicity of WPH. ABE production in batch fermentation by Clostridium beijerinckii increased 68%, from 6.73 g/L in the non-treated and non-diluted WPH to 11.35 g/L in the resin treated WPH. With gas stripping for in situ product removal, ABE production from WPH increased to 17.73 g/L, demonstrating that gas stripping was effective in alleviating butanol toxicity by selectively separating butanol from the fermentation broth, which greatly improved solvents production and sugar conversion in the fermentation. (C) 2013 Elsevier Ltd. All rights reserved.

  1. Toxic hazard and chemical analysis of leachates from furfurylated wood.

    PubMed

    Pilgård, Annica; Treu, Andreas; van Zeeland, Albert N T; Gosselink, Richard J A; Westin, Mats

    2010-09-01

    The furfurylation process is an extensively investigated wood modification process. Furfuryl alcohol molecules penetrate into the wood cell wall and polymerize in situ. This results in a permanent swelling of the wood cell walls. It is unclear whether or not chemical bonds exist between the furfuryl alcohol polymer and the wood. In the present study, five different wood species were used, both hardwoods and softwoods. They were treated with three different furfurylation procedures and leached according to three different leaching methods. The present study shows that, in general, the leachates from furfurylated wood have low toxicity. It also shows that the choice of leaching method is decisive for the outcome of the toxicity results. Earlier studies have shown that leachates from wood treated with furfuryl alcohol prepolymers have higher toxicity to Vibrio fischeri than leachates from wood treated with furfuryl alcohol monomers. This is probably attributable to differences in leaching of chemical compounds. The present study shows that this difference in the toxicity most likely cannot be attributed to maleic acid, furan, furfural, furfuryl alcohol, or 2-furoic acid. However, the difference might be caused by the two substances 5-hydroxymethylfurfural and 2,5-furandimethanol. The present study found no difference in the amount of leached furfuryl alcohol between leachates from furfurylated softwood and furfurylated hardwood species. Earlier studies have indicated differences in grafting of furfuryl alcohol to lignin. However, nothing was found in the present study that could support this. The leachates of furfurylated wood still need to be PMID:20821648

  2. Electro-coagulation treatment efficiency of graphite, iron and aluminum electrodes using alum and wood ash electrolytes on a Kraft pulp and paper mill effluent.

    PubMed

    Orori, O B; Etiégni, L; Senelwa, K; Mwamburi, M M; Balozi, K B; Barisa, G K; Omutange, E S

    2010-01-01

    Specific power consumption and reduction of BOD, COD, TS, pH, and chemical elements were used to determine the treatment efficiency of Fe, graphite and Al electrodes with alum and wood ash as supporting electrolytes on the effluent from a Kraft pulp and paper mill in Kenya. Five sampling points were selected along mill's effluent treatment system: primary settling tank (SP1), first aerated lagoon (SP2), second aerated lagoon (SP3), stabilization pond (SP4), and at discharge point (SP5). Operating costs were also compared between treatments. Graphite electrodes combined with alum showed the lowest power consumption (0.5 to 3.9 mWh/m³), followed by Al and Fe. All the electrodes reduced color from a maximum of 3,200°H to the minimum local standard of 15°H. However Al electrode with alum was the most effective method for BOD and COD reduction by over 60% and 58.8% respectively and generated less sludge at all sampling points. The cost of treatment was lowest with graphite electrode (US$0.006 to 0.0008 per m³ of effluent), but highest with Al electrodes combined with wood ash (US$31.74 to 8.34 per m³). Further study is required for the effectiveness of increasing the concentration of wood ash leachate at higher concentration and current density. PMID:20935369

  3. Effect of different locations on the morphological, chemical, pulping and papermaking properties of Trema orientalis (Nalita).

    PubMed

    Jahan, M Sarwar; Chowdhury, Nasima; Ni, Yonghao

    2010-03-01

    The chemical compositions and fiber morphology of stem and branch samples from Trema orientalis at three different sites planted in Bangladesh were determined and their pulping, bleaching and the resulting pulp properties were investigated. A large difference between the stem and branch samples was observed. The stem samples have consistently higher alpha-cellulose and lower lignin content, and longer fibers than the branch samples in all sites. T. orientalis from the Dhaka and Rajbari region had higher alpha-cellulose content and longer fiber length, resulting in higher pulp yield and better papermaking properties. The T. orientalis pulp from Rajbari region also showed the best bleachability. PMID:19914825

  4. Effect of the pretreatment of poplar and aspen wood by {gamma} irradiation on the delignification and pulping process

    SciTech Connect

    Kotelnikova, N.E.; Kotelnikov, V.P.

    1996-10-01

    Of the possible pretreatment methods radiation (e.g. by r-ray or by high speed electrons) are the most up-to-date and ecologically advantageous ones. Ionizing radiation itself leads to the degradation of polysaccharides, which, however, proceeds with the protecting action of lignin. The aim of this study was to intensify the process of delignification and pulping of poplar and aspen wood by X-irradiation. Simultaneous process of wood delignification and hydrolysis by the action of dilute acid in the presence of inorganic salts was carried out. It was shown that after such pretreatment the rate constants of delignification as well as of hydrolysis depend on the irradiation dose and increase two times as compared to those without this preatreatment. This paper will discuss advantages and deficiencies of the proposed pretreatments and some ideas on their further application.

  5. Chemical composition and structural features of the macromolecular components of plantation Acacia mangium wood.

    PubMed

    Pinto, Paula C; Evtuguin, Dmitry V; Pascoal Neto, Carlos

    2005-10-01

    The wood of Acacia mangium, a prominent fast-growing plantation species used in the pulp-and-paper industry and, so far, poorly investigated for its chemical structure, was submitted to a detailed characterization of its main macromolecular components. Lignin (28% wood weight) isolated by mild acidolysis and characterized by permanganate oxidation, 1H and 13C NMR, and GPC, showed a very low content of syringylpropane-derived units (S:G:H of 48:49:3), a high degree of condensation, a low content of beta-O-4 ( approximately 0.40-0.43 per C6) structures, and a Mw of 2230. Glucuronoxylan (14% wood weight) isolated by alkaline (KOH) or by dimethyl sulfoxide extraction was characterized by methylation analysis, 1H NMR, and GPC. About 10% of the xylopyranose (Xylp) units constituting the linear backbone were substituted at O-2 with 4-O-methylglucuronic acid residues. Almost half of the Xylp units (45%) were O-2 (18%), O-3 (24%) or O-2,3 (3%) acetylated. X-ray diffraction analysis of cellulose (46% wood weight), isolated according to the Kürschner-Hoffer method, showed a degree of crystallinity of 67.6%. PMID:16190642

  6. Green chemicals from pulp production black liquor by partial wet oxidation.

    PubMed

    Muddassar, Hassan Raja; Melin, Kristian; de Villalba Kokkonen, Daniela; Riera, Gerard Viader; Golam, Sarwar; Koskinen, Jukka

    2015-11-01

    To reduce greenhouse gas emissions, more sustainable sources of energy, fuel and chemicals are needed. Biomass side streams such as black liquor, which is a by-product of pulp production, has the potential to be used for this purpose. The aim of the study was the production of carboxylic acids, such as lactic acid, formic acid and acetic acid, from kraft and non-wood black liquor. The processes studied were partial wet oxidation (PWO) and catalytic partial wet oxidation (CPWO). The results show that the yield of carboxylic acid is higher when treated by PWO than the results from CPWO at temperatures of 170 °C and 230 °C. The results shows that the PWO process can increase the yield of carboxylic acids and hydroxy acids in black liquor, reduce lignin content and decrease pH, which makes further separation of the acids more favourable. The hydroxy acids are valuable raw materials for biopolymers, and acetic acid and formic acid are commonly used chemicals conventionally produced from fossil feedstock. PMID:26377325

  7. Cellular biopolymers and molecular structure of a secondary pulp and paper mill sludge verified by spectroscopy and chemical extraction techniques.

    PubMed

    Edalatmanesh, Maryam; Sain, Mohini; Liss, Steven N

    2010-01-01

    For proper treatment, recycling, or disposal of the pulp and paper mill secondary sludge qualitative and quantitative determination of its characteristics are necessary. Chemical extraction, quantitative characterization, and spectroscopic experiments have been performed to determine the molecular composition and chemical functionality of a pulp and paper mill secondary sludge. In order to extract the low-molecular-weight substances, soxhlet extraction with polar and non-polar solvents was performed where most of the target substances (17±1.3%.) were extracted after 2 hours. Over time, this extraction followed a first-order kinetics. Fiber analyses have shown 12±3% lignin, 28±3% cellulose, and 12±4% hemicelluloses content. The ash content was about 17±0.5%. In this work, 7 and 16% intra- and extracellular polymeric substances, respectively, were extracted from the secondary sludge. EPS and mixture of intra- and extracellular biopolymers have shown similar chemical functionalities. These analyses confirmed that the paper secondary sludge consisted mainly of wood fiber, i.e. lignocellulosic substances, along with proteins and polysaccharides originated from microorganisms. PMID:21123914

  8. 25. Wood quench tower, chemical tank on right, hot gas ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. Wood quench tower, chemical tank on right, hot gas pipes between coke ovens and compressor building XX), coal conveyor to pulverizer building on right, water tank to left of quench tower. Looking north/northwest - Rouge Steel Company, 3001 Miller Road, Dearborn, MI

  9. Canola straw chemimechanical pulping for pulp and paper production.

    PubMed

    Hosseinpour, Reza; Fatehi, Pedram; Latibari, Ahmad Jahan; Ni, Yonghao; Javad Sepiddehdam, S

    2010-06-01

    Non-wood is one of the most important raw materials for pulp and paper production in several countries due to its abundance and cost-effectiveness. However, the pulping and papermaking characteristics of canola straw have rarely been investigated. The objective of this work was to determine the potential application of canola straw in the chemimechanical pulping (CMP) process. At first, the chemical composition and characteristics of canola straw were assessed and compared with those of other non-woods. Then, the CMP pulping of canola straw was conducted using different dosages of sodium sulfite and sodium hydroxide. The results showed that, by applying a mild chemical pretreatment, i.e., 4-12% (wt.) NaOH and 8-12% (wt.) Na(2)SO(3), in the CMP pulping of canola straw, the pulp brightness reached almost 40%ISO, and the strength properties were comparable to those of bagasse CMP and of wheat straw CMP. The impact of post-refining on the properties of canola straw CMP was also discussed in this work. PMID:20144862

  10. 40 CFR 63.443 - Standards for the pulping system at kraft, soda, and semi-chemical processes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Paper Industry § 63.443 Standards for the pulping system at kraft, soda, and semi-chemical processes. (a... kraft, soda, and semi-chemical processes. 63.443 Section 63.443 Protection of Environment ENVIRONMENTAL... operator of each pulping system using a semi-chemical or soda process subject to the requirements of...

  11. 40 CFR 63.443 - Standards for the pulping system at kraft, soda, and semi-chemical processes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Paper Industry § 63.443 Standards for the pulping system at kraft, soda, and semi-chemical processes. (a... kraft, soda, and semi-chemical processes. 63.443 Section 63.443 Protection of Environment ENVIRONMENTAL... operator of each pulping system using a semi-chemical or soda process subject to the requirements of...

  12. 40 CFR 63.443 - Standards for the pulping system at kraft, soda, and semi-chemical processes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Paper Industry § 63.443 Standards for the pulping system at kraft, soda, and semi-chemical processes. (a... kraft, soda, and semi-chemical processes. 63.443 Section 63.443 Protection of Environment ENVIRONMENTAL... operator of each pulping system using a semi-chemical or soda process subject to the requirements of...

  13. 40 CFR 63.443 - Standards for the pulping system at kraft, soda, and semi-chemical processes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... kraft, soda, and semi-chemical processes. 63.443 Section 63.443 Protection of Environment ENVIRONMENTAL... Paper Industry § 63.443 Standards for the pulping system at kraft, soda, and semi-chemical processes. (a... operator of each pulping system using a semi-chemical or soda process subject to the requirements of...

  14. 40 CFR 63.443 - Standards for the pulping system at kraft, soda, and semi-chemical processes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... kraft, soda, and semi-chemical processes. 63.443 Section 63.443 Protection of Environment ENVIRONMENTAL... Paper Industry § 63.443 Standards for the pulping system at kraft, soda, and semi-chemical processes. (a... operator of each pulping system using a semi-chemical or soda process subject to the requirements of...

  15. Kinetics of PCDD/Fs formation from non-wood pulp bleaching with chlorine.

    PubMed

    Wang, Xueli; Zhang, Haijun; Ni, Yuwen; Du, Qinqin; Zhang, Xueping; Chen, Jiping

    2014-04-15

    Chlorine bleaching is still practiced by most of nonwood pulp and paper mills, resulting in a considerable amount of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) formation and emission. In this study, the effects of primary chlorination conditions on the formation of PCDD/Fs from nonwood pulp bleaching with elemental chlorine were investigated. It was found that low-chlorinated PCDD/Fs were usually formed and then underwent further chlorination to form highly chlorinated PCDD/Fs with increasing chlorination time. Higher available chlorine dosages and lower system pH values greatly accelerated dioxin formation, and pH 3 was the threshold for the formation of tetra- to octa-CDD/Fs. Higher temperatures promoted the formation of lower-chlorinated PCDD/Fs, while caused significant reduction of tetra- to hepta-CDDs and penta- to octa-OCDFs. PCDFs were formed much faster than PCDDs. A first-order kinetic model showed a good fit to the data for tetra- to oct-CDFs formation under different chlorination conditions, indicating that chlorine substitution was the rate determining step for their formation. Finally, the optimum chlorination conditions for minimizing and eliminating the formation of 2,3,7,8-TCDD/TCDF in nonwood pulp bleaching with elemental chlorine were established. PMID:24660967

  16. Betulinol and wood sterols in sediments contaminated by pulp and paper mill effluents: dissolution and spatial distribution.

    PubMed

    Ratia, H; Rämänen, H; Lensu, A; Oikari, A

    2013-07-01

    The goal was to determine dissolution potency of betulinol and wood sterols (WSs) from pulp and paper mill-contaminated sediments and the current stratification for assessment the load due to potential erosion in the river-like watercourse. Both compounds are wood extractives, which may be toxic to benthos and fish. This research continues a study in which other wood extractives, resin acids and their derivative, retene, were analysed. Sediments were collected from 1, 3.5, 12, 15, and 33 km downstream from the pulp and paper mills, and from 2 upstream reference sites. The dissolution potency into sediment-water elutriates (1 + 4 v/v) was studied by two agitation times and temperatures. The vertical amounts of extractives were determined from the uppermost 20 cm of sediment. The amounts of extractives potentially released were estimated from the sediment layers 0-2 and 2-5 cm by using spatial interpolation. According to the interpolation, the total amount of betulinol and β-sitosterol was calculated as kg/ha in the whole sediment area. Significant concentrations of betulinol (1,666 μg/g, dw) and WSs (2,886 μg/g, dw) were measured from the sediments. According spatial interpolation, the highest calculated amount of betulinol (4,726 kg/ha) and that of the most abundant WS, β-sitosterol (3,571 kg/ha), were in the lake where the effluents were discharged. In the dissolution experiment, the highest concentration of betulinol in sediment (0-10 cm) and elutriate was 412 μg/g (dw) and 165 μg/l, respectively. For WSs, concentrations were 768 μg/g (dw) in sediment and 273 μg/l in elutriate. In a worst-case scenario, betulinol may be desorbed to water in concentrations which are hazardous to aquatic animals. Instead WSs are not a risk in this study area. The amount of desorption varied depending on the concentration of contaminants in sediment, the nature of disturbance, and the sediment organic carbon content. PMID:23263757

  17. Chemical Markers of Occupational Exposure to Teak Wood Dust

    PubMed Central

    Carrieri, Mariella; Bartolucci, Giovanni Battista; Lee, Taekhee; Barbero, Ana; Harper, Martin

    2014-01-01

    A novel high-performance liquid chromatographic/ultraviolet method was developed to detect lapachol (LP) and deoxylapachol (DLP) in wood dust as chemical markers of teak wood (a suspected human carcinogen). The specificity of this analysis was determined by noting the absence of LP and DLP in 12 other specimens of different woods belonging to the angiosperm family. The consistency was examined by analyzing teak from three different sources, where the percentages (wt/wt) of the chemicals ranged from 0.006 to 0.261 for LP and from 0.038 to 0.497 for DLP, respectively. Although the LP and DLP components of teak varied according to source, a very high correlation coefficient (r 2 > 0.98 always) was found between the content of the two markers in the bulk specimens and in bulk dust derived from them. The method was then applied to teak dust collected on polyvinylchloride filters from aerosol in an exposure chamber in the range of mass loadings between 0.03 and 3.65mg, which corresponds to a dust exposure between 0.124 and 8.703mg m−3 for a sampling time of 2h. A field test was also carried out in a small factory where teak was used. A good correlation was confirmed between LP and DLP versus the dust collected on the filter in both cases. LP and DLP can be markers to estimate the true quantities of teak dust inhaled in a workplace with mixed wood dust, provided the results are matched to the content of LP and DLP in the bulk wood. LP and DLP have also been proposed as the agents responsible for allergic reaction to teak dust. Therefore, it would be useful to evaluate the exposure to these two substances even without a relationship to teak dust exposure. PMID:24671613

  18. Chemical markers of occupational exposure to teak wood dust.

    PubMed

    Carrieri, Mariella; Bartolucci, Giovanni Battista; Lee, Taekhee; Barbero, Ana; Harper, Martin

    2014-06-01

    A novel high-performance liquid chromatographic/ultraviolet method was developed to detect lapachol (LP) and deoxylapachol (DLP) in wood dust as chemical markers of teak wood (a suspected human carcinogen). The specificity of this analysis was determined by noting the absence of LP and DLP in 12 other specimens of different woods belonging to the angiosperm family. The consistency was examined by analyzing teak from three different sources, where the percentages (wt/wt) of the chemicals ranged from 0.006 to 0.261 for LP and from 0.038 to 0.497 for DLP, respectively. Although the LP and DLP components of teak varied according to source, a very high correlation coefficient (r (2) > 0.98 always) was found between the content of the two markers in the bulk specimens and in bulk dust derived from them. The method was then applied to teak dust collected on polyvinylchloride filters from aerosol in an exposure chamber in the range of mass loadings between 0.03 and 3.65 mg, which corresponds to a dust exposure between 0.124 and 8.703 mg m(-3) for a sampling time of 2h. A field test was also carried out in a small factory where teak was used. A good correlation was confirmed between LP and DLP versus the dust collected on the filter in both cases. LP and DLP can be markers to estimate the true quantities of teak dust inhaled in a workplace with mixed wood dust, provided the results are matched to the content of LP and DLP in the bulk wood. LP and DLP have also been proposed as the agents responsible for allergic reaction to teak dust. Therefore, it would be useful to evaluate the exposure to these two substances even without a relationship to teak dust exposure. PMID:24671613

  19. Model pollution prevention plan for the kraft segment of the pulp and paper industry

    SciTech Connect

    Not Available

    1992-09-01

    The document provides a generic process-by-process assessment of pollution prevention opportunities for the Kraft segment of the pulp and paper industry. The process areas covered are: wood yard operations, pulping and chemical recovery, pulp bleaching, pulp drying and papermaking, and wastewater treatment. These process areas are further broken down by specific process (e.g., oxygen delignification as one specific process under the pulping and chemical recovery area). For each specific process there is a description, a cost estimate, a discussion of applicability, and estimate of environmental benefits, and a list of references.

  20. Control of the Accumulation of Non-Process Elements in Pulp Mills with Bleach Filtrate Reuse: A Chemical Equilibrium Approach to Predicting the Partitioning of Metals in Pulp Mill and Bleach Plant Streams

    SciTech Connect

    Frederick, W.J. Jr.; Rudie, A.W.; Schmidl, G.W.; Sinquefield, S.A.; Rorrer, G.L.; Laver, M.L.; Yantasee, W.; Ming, D.

    2000-08-01

    The overall goal of this project was to develop fundamental, experimentally based methods for predicting the solubility or organic and inorganic matter and their interactions in recycled effluent from kraft pulp mills and bleach plants. This included: characterizing the capacity of wood pulp and dissolved organic matter to bind metal ions, developing a thermodynamic database of properties needed to describe the solubility of inorganic matter in pulp mill streams, incorporation of the database into equilibrium calculation software for predicting the solubility of the metals of interest, and evaluating its capability to predict the distribution of the metals between pulp fibers, inorganic precipitates, and solution.

  1. Application of enzyme for improvement of Acacia APMP pulping and refining of mixed pulp for printing papermaking in Vietnam.

    PubMed

    Dien, Le Quang; Hoang, Phan Huy; Tu, Do Thanh

    2014-02-01

    This study assesses the influence of commercial enzyme (FibreZyme LBR) treatment applied to APMP pulp and to the mixture of 55% Acacia CTMP75 pulp, 30% soft-wood bleached chemical pulp (LBKP 90 from Chile) and 15% hard-wood bleached chemical pulp (NPKP 90 from Indonesia). The treatment was conducted at different temperatures, reaction times and enzyme dosages. The APMP and mixed pulp treated with the enzyme showed a significant decrease of refining time to achieve the same refining degree (Schopper-Riegler freeness, °SR) and better mechanical-physical properties due to the development of fibrillation. The fibre morphology difference between before and after treatment was revealed by the microscopic observations performed by a scanning electron microscope (SEM). The SEM analysis showed that the surface of the enzyme-treated fibre had some swelling and fibrillar phenomenon that lead to strong paper properties such as tear index, tensile index and burst index. PMID:24222497

  2. Sensitivity of human dental pulp cells to eighteen chemical agents used for endodontic treatments in dentistry.

    PubMed

    Kobayashi, Morio; Tsutsui, Takeo W; Kobayashi, Tomoko; Ohno, Maki; Higo, Yukari; Inaba, Tomohiro; Tsutsui, Takeki

    2013-01-01

    To determine the adverse effects against human dental pulp tissue, the sensitivity of human dental pulp cells (D824 cells) to 18 chemical agents used for endodontic treatments in dentistry was examined. The cytotoxicity, as determined by a decrease in colony-forming ability of cells treated with the chemical agents, increased as the concentration increased. As a quantitative measure of the cytotoxic effect, LC(50), the concentration which induces a 50% lethality, was extrapolated from the concentration-response curves. The rank of the chemical agents according to their cytotoxic effect (LC(50)) was sodium arsenite > formaldehyde > hydrogen peroxide > zinc oxide > thymol ≈ iodoform ≈ eugenol > guaiacol > ethylenediaminetetraacetic acid ≈ iodine > procaine > lidocaine ≈ chloramphenicol ≈ m-cresol > calcium hydroxide ≈ sodium hypochlorite ≈ phenol ≈ p-phenolsulfonic acid. To compare the cytotoxicity and the levels of apoptosis and mRNA expression of five genes related to the function of dental pulp tissue, D824 cells treated with the LC(50) concentrations of chemical agents were assayed by the TUNEL method and quantitative reverse transcription polymerase chain reaction analysis, respectively. The inducibility of apoptotic cells and the level of mRNA expression of the genes varied with the chemical agents, indicating that both effects occurred independent of the rank of cytotoxic effect of the chemical agents. The results not only provide information concerning cytotoxicity of various chemical agents to human dental pulp cells, but also show an insight into the diversity of the pharmacodynamic action of the chemical agents. PMID:22083529

  3. Not Just Lumber—Using Wood in the Sustainable Future of Materials, Chemicals, and Fuels

    NASA Astrophysics Data System (ADS)

    Jakes, Joseph E.; Arzola, Xavier; Bergman, Rick; Ciesielski, Peter; Hunt, Christopher G.; Rahbar, Nima; Tshabalala, Mandla; Wiedenhoeft, Alex C.; Zelinka, Samuel L.

    2016-07-01

    Forest-derived biomaterials can play an integral role in a sustainable and renewable future. Research across a range of disciplines is required to develop the knowledge necessary to overcome the challenges of incorporating more renewable forest resources in materials, chemicals, and fuels. We focus on wood specifically because in our view, better characterization of wood as a raw material and as a feedstock will lead to its increased utilization. We first give an overview of wood structure and chemical composition and then highlight current topics in forest products research, including (1) industrial chemicals, biofuels, and energy from woody materials; (2) wood-based activated carbon and carbon nanostructures; (3) development of improved wood protection treatments; (4) massive timber construction; (5) wood as a bioinspiring material; and (6) atomic simulations of wood polymers. We conclude with a discussion of the sustainability of wood as a renewable forest resource.

  4. Pollution prevention in the pulp and paper industry

    SciTech Connect

    Jenkins, P.G.

    1995-09-01

    Probably no other industry has made as much progress as the kraft pulp and paper industry in reclaiming waste products. About half of the wood used in making pulp is cellulose; the reclamation of the other ingredients in the wood constitutes a continuing evolution of pollution prevention and economic success. The by-products of chemical pulping include turpentine used in the paint industry, lignosulfonates used as surfactants and dispersants, ``tall oil`` used in chemical manufacturing, yeast, vanillin, acetic acid, activated carbon, and alcohol. Sulfamic turpentine recovered in the kraft process is used to manufacture pine oil, dimethyl sulfoxide (DMSO), and other useful chemical products. In addition, the noncellulose portion of the wood is used to provide energy for the pulping process through the combustion of concentrated black liquor. Over 75% of the pulp produced in the US is manufactured using the kraft process. Because of the predominance of the kraft process, the remainder of this section will address pollution prevention methods for kraft pulp and paper mills. Some of these techniques may be applicable or adaptable to other pulping processes, especially sulfite mills. The major steps in the kraft process are described, followed by a discussion of major wastestreams, and proven pollution prevention methods for each of these steps.

  5. Size fractionation of wood extractives, lignin and trace elements in pulp and paper mill wastewater before and after biological treatment.

    PubMed

    Leiviskä, Tiina; Rämö, Jaakko; Nurmesniemi, Hannu; Pöykiö, Risto; Kuokkanen, Toivo

    2009-07-01

    Integrated kraft pulp and paper mill wastewater was characterized before (influent) and after (effluent) the activated sludge process by microfiltration (8, 3, 0.45 and 0.22 microm) and ultrafiltration (100, 50, 30 and 3 kDa) into different size fractions. Wood extractives, lignin, suspended solids and certain trace elements were determined in each fraction. Forty four percent of the resin and fatty acids in the influent (12.8 mg/L) occurred in particles (>0.45 microm), 20% as colloids (0.45 microm-3 kDa) and 36% in the <3 kDa fraction. The corresponding values for sterols (1.5 mg/L) were 5, 46 and 49%. In the effluent, resin and fatty acids (1.45 mg/L) and sterols (0.26 mg/L) were mainly present in the <3 kDa fraction, as well as a small proportion in particles. beta-sitosterol was present in particles in the effluent (88+/-50 microg/L). Lignin in the influent was mainly in the colloidal and <3 kDa fractions, whereas in the effluent it was mainly in the <3 kDa fraction. Thus the decrease of lignin in the biological treatment was concentrated on the colloidal fraction. In the influent, Mn, Zn and Si were mainly present in the <3 kDa fraction, whereas a significant proportion of Fe and Al were found also in the particle and colloidal fractions. In the effluent, Fe and Al were mainly present in the colloidal fraction; in contrast, Mn, Zn and Si were mainly in the <3 kDa fraction. The results indicated that the release of certain compounds and elements into the environment could be significantly decreased or even prevented simply by employing microfiltration as a final treatment step or by enhancing particle removal in the secondary clarifier. PMID:19524281

  6. Steam system opportunity assessment for the pulp and paper, chemical manufacturing, and petroleum refining industries: Main report

    SciTech Connect

    None, None

    2002-10-01

    This report assesses steam generation and use in the pulp and paper, chemical, and petroleum refining industries, and estimates the potential for energy savings from implementation of steam system performance and efficiency improvements.

  7. Dry Kraft Pulping at Ambient Pressure for Cost Effective Energy Saving and Pollution Deduction

    SciTech Connect

    Yulin Deng; Art Ragauskas

    2012-08-28

    Sponsored by the DOE Industrial Energy Efficiency Grand Challenge program, our research team at the Georgia Institute of Technology conducted laboratory studies and confirmed the concept of making wood pulp using a dry pulping technology. This technology is a new process different from any prior pulping technology used in Kraft and CTMP pulping. Three different kinds of dry pulping methods were investigated. (a) Dry Pulping at Atmospheric Pressure: The first one is to dry and bake the pretreated woodchips in a conventional oven at atmospheric pressure without the use of a catalyst. (b) Dry Pulping at Reduced Pressure: The second method is to dry the pretreated woodchips first in a vacuum oven in the presence of anthraquinone (AQ) as a pulping catalyst, followed by baking at elevated temperature. (c) Liquid Free Chemical Pulping, LFCP. The third method is to first remove the free water of pretreated woodchips, followed by dry pulping using a conventional Kraft pulping digester with AQ and triton as additives. Method one: Experimental results indicated that Dry Pulping at Atmospheric Pressure could produce pulp with higher brightness and lower bulk than conventional Kraft pulp. However, tensile strength of the acquired pulp is much lower than traditional Kraft pulp, and their Kappa number and energy consumption are higher than conventional Kraft pulp. By fully analyzing the results, we concluded that wood fibers might be damaged during the drying process at elevated temperature. The main reason for wood fiber damage is that a long drying time was used during evaporation of water from the woodchips. This resulted in an un-uniform reaction condition on the woodchips: the outside layer of the woodchips was over reacted while inside the woodchips did not reacted at all. To solve this problem, dry pulping at reduced pressure was investigated. Method two: To achieve uniform reaction throughout the entire reaction system, the water inside the pretreated woodchips was

  8. [Chemical characteristics of the pulp and oil of the annona tree (Annona coriaceae)].

    PubMed

    Agostini, T da S; Cecchi, H M; Barrera-Arellano, D

    1995-09-01

    Belonging to the Annonaceae family, marolo (Annona coriaceae) is a native species of the Brazilian "cerrado" región (Minas Gerais, Goiás and Distrito Federal) and can be found in South American tropical zones. Its fruits are highly consumed by local people and commercialized in markets or street stalls. There is, however, a tendency for the extinction of marolo due to deforestation and the large scale plantation of monocultures instead of native plants. The literature still offers no data on the chemical composition of the proximate composition and vitamin C, A and tannin contents were carried out on the yellow marolo pulp as well as the determination of the physico-chemical characteristics of the seed oil. Five batches of fruit from the Alfenas region--south of Minas Gerais State--were analysed in this work and their average composition were: humidity 77%, total sugar 15%, reducing sugar 11%, crude protein 1%, lipids 3%, fiber 5% and fixed mineral residue 1%. The contents of vitamin C and A were 8.2 mg/100g and 117.5 RE/100g, respectively, and the tannin content was 245 mg/100g. The results showed high fiber and lipid contents of marolo pulp in comparison with many other tropical fruit pulps. The vitamin C contents were equivalent to those found in avocado, pineapple and watermelon, while the vitamin A contents were equivalent to papaya, peach, guava and several other tropical fruits. Marolo seed contains 45% of oil on a dry basis. Its composition and physico-chemical characteristics showed the possibility of producing a good quality oil, with great potential for the fine oil market. However the presence of alkaloids in the oil needs to be further studied. Their elimination could be done by refining or extraction in a continuous press. The results exalt the high quality of marolo pulp, showing that the preservation of native species should be stimulated. PMID:9382684

  9. Recovery of palladium using chemically modified cedar wood powder.

    PubMed

    Parajuli, Durga; Hirota, Koichi

    2009-10-15

    Japanese cedar wood powder (CWP) was chemically modified to a tertiary-amine-type adsorbent and studied for the selective recovery of Pd(II) from various industrial waters. Batch adsorption tests performed from 0.1 M to 5 M HCl and HNO3 systems reveal stable performance with better results in HNO3 medium. The maximum loading capacity for Pd(II) was studied in HCl as well as in HNO3. A continuous-flow experiment taking a real industrial solution revealed the feasibility of using modified CWP for the selective uptake and preconcentration of traces of palladium contained in acidic effluents. In addition, stable adsorption performance even on long exposure to gamma-irradiation and selective recovery of palladium from simulated high-level liquid waste (HLW) are important outcomes of the study. PMID:19640546

  10. Alkaline peroxide pulping of oil palm empty fruit bunch by variation of chemical strength

    NASA Astrophysics Data System (ADS)

    Dermawan, Yunita Megasari; Ghazali, Arniza; Daud, Wan Rosli Wan; Lazin, Mohd Azli Khairil Mat

    2012-09-01

    Papers produced from oil palm empty fruit bunches (EFB) via Alkaline Peroxide Pulping (APP) was preceded by three main steps; dewaxing of EFB, alkaline peroxide (AP) impregnation into EFB and refining of biomass to generate pulp. The experiment was carried by varying chemical level and number of impregnation stages. For 2:2.5% AP level, two-stage impregnation improved hand sheets tear index by 45%, 164% boost in tensile index, 26% enhancement in zero span index and more than 5% in burst index. By applying 8:10% AP level, significant improvements were gained at the third and fourth stages of AP impregnation. Although there was no significant change in hand sheet strength with multiple impregnation for 4:5% AP level, improvement in brightness of hand sheets was apparent, analogous to the effect of increasing AP level. The found paper properties development show that alkaline peroxide pulping of EFB could be adapted to various targeted properties by adjustment of AP level and impregnation stages.

  11. Identification of the need for research on chemical tracers to detect pulp mill effluent exposure

    SciTech Connect

    Ali, N.; Humphrey, S.; Van Coillie, R.

    1995-12-31

    A critical factor in the assessment of the effects of effluent exposure on sampled biota is the verification of exposure in nearfield and farfield zones and verification of the lack of exposure in the reference areas. At mills with rapid dilution of effluent, or where physical barriers to fish movement between exposure and reference areas do not exist, an appropriate fish tracer must be used. In Canada, because of multiple industrial and municipal discharges at certain pulp mill sites, it is difficult to assess the effects of the mill effluent in isolation from those of neighboring influences unless tracers specific to the different effluents are used. Examples of substances proposed as tracers for pulp mill effluent include resin acids, chloroguaiacols, chlorophenols, dioxin, and furan congeners. This paper gives a summary of tracer substances used to date and the problems encountered in selecting and measuring suitable chemical tracers for regulated environmental effects monitoring studies at Canadian mills. Based on their experience, there is urgent need for research into appropriate tracer substances for pulp mill as well as other industrial and municipal effluents.

  12. Wood Chemical Composition in Species of Cactaceae: The Relationship between Lignification and Stem Morphology

    PubMed Central

    Canché-Escamilla, Gonzalo; Soto-Hernández, Marcos

    2015-01-01

    In Cactaceae, wood anatomy is related to stem morphology in terms of the conferred support. In species of cacti with dimorphic wood, a unique process occurs in which the cambium stops producing wide-band tracheids (WBTs) and produces fibers; this is associated with the aging of individuals and increases in size. Stem support and lignification have only been studied in fibrous tree-like species, and studies in species with WBTs or dimorphic wood are lacking. In this study, we approach this process with a chemical focus, emphasizing the role of wood lignification. We hypothesized that the degree of wood lignification in Cactaceae increases with height of the species and that its chemical composition varies with wood anatomy. To test this, we studied the chemical composition (cellulose, hemicellulose, and lignin content) in 13 species (2 WBTs wood, 3 dimorphic, and 8 fibrous) with contrasting growth forms. We also analyzed lignification in dimorphic and fibrous species to determine the chemical features of WBTs and fibers and their relationship with stem support. The lignin contents were characterized by Fourier transform infrared spectroscopy and high performance liquid chromatography. We found that 11 species have a higher percentage (>35%) of lignin in their wood than other angiosperms or gymnosperms. The lignin chemical composition in fibrous species is similar to that of other dicots, but it is markedly heterogeneous in non-fibrous species where WBTs are abundant. The lignification in WBTs is associated with the resistance to high water pressure within cells rather than the contribution to mechanical support. Dimorphic wood species are usually richer in syringyl lignin, and tree-like species with lignified rays have more guaiacyl lignin. The results suggest that wood anatomy and lignin distribution play an important role in the chemical composition of wood, and further research is needed at the cellular level. PMID:25880223

  13. Exploring the effects of treatments with carbohydrases to obtain a high-cellulose content pulp from a non-wood alkaline pulp.

    PubMed

    Beltramino, Facundo; Valls, Cristina; Vidal, Teresa; Roncero, M Blanca

    2015-11-20

    In this work, treatments with a xylanase (X) and carbohydrases mixture (Cx) were applied on a TCF bleached sisal pulp in order to obtain high-cellulose content fibers applicable on a wide range of uses. A limit of ≈12% w/w final content in hemicelluloses was found regardless of the enzymatic treatment assessed. An extraction with 4% and 9% w/v NaOH was performed for further hemicelluloses removal. We found that NaOH dose could be strongly reduced if combined with Cx or Cx+X treatments. Also, if necessary, a stronger reduction could be obtained with 9% w/v NaOH, which was found to be boosted in a 14% if performed after a treatment with Cx. An end-product with a low content in xylans (≈2.9% w/w) and in HexA (5.8μmol/odp) was obtained. Pulp Fock solubility was also increased (≈30%) by enzymatic treatments. HPLC analysis of effluents provided useful information of enzymatic catalytic mechanisms. PMID:26344285

  14. Physical and chemical characterization of waste wood derived biochars.

    PubMed

    Yargicoglu, Erin N; Sadasivam, Bala Yamini; Reddy, Krishna R; Spokas, Kurt

    2015-02-01

    Biochar, a solid byproduct generated during waste biomass pyrolysis or gasification in the absence (or near-absence) of oxygen, has recently garnered interest for both agricultural and environmental management purposes owing to its unique physicochemical properties. Favorable properties of biochar include its high surface area and porosity, and ability to adsorb a variety of compounds, including nutrients, organic contaminants, and some gases. Physical and chemical properties of biochars are dictated by the feedstock and production processes (pyrolysis or gasification temperature, conversion technology and pre- and post-treatment processes, if any), which vary widely across commercially produced biochars. In this study, several commercially available biochars derived from waste wood are characterized for physical and chemical properties that can signify their relevant environmental applications. Parameters characterized include: physical properties (particle size distribution, specific gravity, density, porosity, surface area), hydraulic properties (hydraulic conductivity and water holding capacity), and chemical and electrochemical properties (organic matter and organic carbon contents, pH, oxidation-reduction potential and electrical conductivity, zeta potential, carbon, nitrogen and hydrogen (CHN) elemental composition, polycyclic aromatic hydrocarbons (PAHs), heavy metals, and leachable PAHs and heavy metals). A wide range of fixed carbon (0-47.8%), volatile matter (28-74.1%), and ash contents (1.5-65.7%) were observed among tested biochars. A high variability in surface area (0.1-155.1g/m(2)) and PAH and heavy metal contents of the solid phase among commercially available biochars was also observed (0.7-83 mg kg(-1)), underscoring the importance of pre-screening biochars prior to application. Production conditions appear to dictate PAH content--with the highest PAHs observed in biochar produced via fast pyrolysis and lowest among the gasification

  15. Laccase-Catalyzed Surface Modification of Thermo-Mechanical Pulp (TMP) for the Production of Wood Fiber Insulation Boards Using Industrial Process Water

    PubMed Central

    Schubert, Mark; Ruedin, Pascal; Civardi, Chiara; Richter, Michael; Hach, André; Christen, Herbert

    2015-01-01

    Low-density wood fiber insulation boards are traditionally manufactured in a wet process using a closed water circuit (process water). The water of these industrial processes contains natural phenolic extractives, aside from small amounts of admixtures (e.g., binders and paraffin). The suitability of two fungal laccases and one bacterial laccase was determined by biochemical characterization considering stability and substrate spectra. In a series of laboratory scale experiments, the selected commercial laccase from Myceliophtora thermophila was used to catalyze the surface modification of thermo-mechanical pulp (TMP) using process water. The laccase catalyzed the covalent binding of the phenolic compounds of the process water onto the wood fiber surface and led to change of the surface chemistry directly via crosslinking of lignin moieties. Although a complete substitution of the binder was not accomplished by laccase, the combined use of laccase and latex significantly improved the mechanical strength properties of wood fiber boards. The enzymatically-treated TMP showed better interactions with the synthetic binder, as shown by FTIR-analysis. Moreover, the enzyme is extensively stable in the process water and the approach requires no fresh water as well as no cost-intensive mediator. By applying a second-order polynomial model in combination with the genetic algorithm (GA), the required amount of laccase and synthetic latex could be optimized enabling the reduction of the binder by 40%. PMID:26046652

  16. Laccase-Catalyzed Surface Modification of Thermo-Mechanical Pulp (TMP) for the Production of Wood Fiber Insulation Boards Using Industrial Process Water.

    PubMed

    Schubert, Mark; Ruedin, Pascal; Civardi, Chiara; Richter, Michael; Hach, André; Christen, Herbert

    2015-01-01

    Low-density wood fiber insulation boards are traditionally manufactured in a wet process using a closed water circuit (process water). The water of these industrial processes contains natural phenolic extractives, aside from small amounts of admixtures (e.g., binders and paraffin). The suitability of two fungal laccases and one bacterial laccase was determined by biochemical characterization considering stability and substrate spectra. In a series of laboratory scale experiments, the selected commercial laccase from Myceliophtora thermophila was used to catalyze the surface modification of thermo-mechanical pulp (TMP) using process water. The laccase catalyzed the covalent binding of the phenolic compounds of the process water onto the wood fiber surface and led to change of the surface chemistry directly via crosslinking of lignin moieties. Although a complete substitution of the binder was not accomplished by laccase, the combined use of laccase and latex significantly improved the mechanical strength properties of wood fiber boards. The enzymatically-treated TMP showed better interactions with the synthetic binder, as shown by FTIR-analysis. Moreover, the enzyme is extensively stable in the process water and the approach requires no fresh water as well as no cost-intensive mediator. By applying a second-order polynomial model in combination with the genetic algorithm (GA), the required amount of laccase and synthetic latex could be optimized enabling the reduction of the binder by 40%. PMID:26046652

  17. Chemical structure of wood charcoal by infrared spectroscopy and multivariate analysis.

    PubMed

    Labbé, Nicole; Harper, David; Rials, Timothy; Elder, Thomas

    2006-05-17

    In this work, the effect of temperature on charcoal structure and chemical composition is investigated for four tree species. Wood charcoal carbonized at various temperatures is analyzed by mid infrared spectroscopy coupled with multivariate analysis and by thermogravimetric analysis to characterize the chemical composition during the carbonization process. The multivariate models of charcoal were able to distinguish between species and wood thermal treatments, revealing that the characteristics of the wood charcoal depend not only on the wood species, but also on the carbonization temperature. This work demonstrates the potential of mid infrared spectroscopy in the whiskey industry, from the identification and classification of the wood species for the mellowing process to the chemical characterization of the barrels after the toasting and charring process. PMID:19127715

  18. Refining of Polysulfide Pulps

    NASA Astrophysics Data System (ADS)

    Copur, Yalcin

    This study compares the modified kraft process, polysulfide pulping, one of the methods to obtain higher pulp yield, with conventional kraft method. More specifically, the study focuses on the refining effects of polysulfide pulp, which is an area with limited literature. Physical, mechanical and chemical properties of kraft and polysulfide pulps (4% elemental sulfur addition to cooking digester) cooked under the same conditions were studied as regards to their behavior under various PFI refining (0, 3000, 6000, 9000 revs.). Polysulfide (PS) pulping, compared to the kraft method, resulted in higher pulp yield and higher pulp kappa number. Polysulfide also gave pulp having higher tensile and burst index. However, the strength of polysulfide pulp, tear index at a constant tensile index, was found to be 15% lower as compared to the kraft pulp. Refining studies showed that moisture holding ability of chemical pulps mostly depends on the chemical nature of the pulp. Refining effects such as fibrillation and fine content did not have a significant effect on the hygroscopic behavior of chemical pulp.

  19. Wood ash: an unusual cause of a chemical burn.

    PubMed

    Kiliç, Azize; Kiliç, Ali

    2002-02-01

    The case illustrates the dangers of wood ash even though it appears harmless. People believe that this folklore medicine remedy provides relief of pain, but it is obviously an inappropriate preparation and a risky procedure. PMID:11834340

  20. Chemical alterations of pine wood saccharides during heat sterilisation.

    PubMed

    Kačík, František; Šmíra, Pavel; Kačíková, Danica; Veľková, Veronika; Nasswettrová, Andrea; Vacek, Vladimír

    2015-03-01

    Alterations in saccharides during heat sterilisation of pine wood (Pinus sylvestris L.) were investigated. The mass loss, extractives, lignin, cellulose, holocellulose and hemicelluloses were determined. Changes in saccharides were evaluated by the determination of monosaccharides in wood, size exclusion chromatography (SEC) as well as Fourier transform infrared (FTIR) spectroscopy. During heat sterilisation of pine wood the slight mass loss, an increase in extractives and a decrease in lignin and polysaccharides were observed. Hemicelluloses are degraded approximately twice as fast as cellulose. The degree of polymerisation of cellulose decreases approximately by 10% and it increases in holocellulose (by approx. 8%) as a result of a faster degradation of shorter hemicellulose chains. FTIR spectroscopy shows that sterilisation results in the deacetylation of cellulose and the formation of new carbonyl groups, an increase in the total crystallinity index (TCI) and a decrease in the lateral order index (LOI) and the hydrogen-bond intensity (HBI). PMID:25498688

  1. Chemicals from wood: the policy implications of federal subsidy. Volume 2. Analysis and conclusions

    SciTech Connect

    Johnson, R.C.; Miller, C.G.; Neuworth, M.B.; Talib, A.

    1983-01-01

    This report addresses the policy implications involving the production of ethanol, furfural, and phenol from the breakdown of wood, and methanol and acetic acid from wood gasification. The selection process for high value-added chemicals from biomass is examined, and the primary and secondary screening criteria are considered. The projected levels of market penetration for the five chemicals from wood are summarized, the principal petrochemical feedstocks that would be displaced are noted, and the critical uncertainties in the projections are explored. Ethanol from wood is said to be competitive with synthetic ethanol for approximately half the total chemical market for ethanol. Furfural is likely to be co-produced with ethanol from wood; it is predicted that additional markets for furfural will open up if the price of furfural decreases. The production of phenol is shown to be one option for the use of the lignin fraction of wood. The policy issues of Federal supports for chemicals from biomass are analyzed. Reviewer comments are appended to the report.

  2. TREATING WOOD PRESERVING PLANT WASTEWATER BY CHEMICAL AND BIOLOGICAL METHODS

    EPA Science Inventory

    A completely mixed activated sludge system was designed for a wood preserving plant with an average daily wastewater flow of 27,000 l/day (7,150 gal/day), a BOD concentration of 1,100 mg/l, and a phenol concentration of 120 mg/l. Included in the design were capabilities for pre- ...

  3. Production of chemical feedstock by the methanolysis of wood

    DOEpatents

    Steinberg, M.; Fallon, P.

    1983-06-01

    A process is discussed for the production of ethylene, benzene and carbon monoxide from particulated biomass such as wood by reaction with methane at a temperature of from 700/sup 0/C to 1200/sup 0/C, at a pressure of from 20 psi to 100 psi for a period of from 0.2 to 10 seconds.

  4. Production of chemical feedstock by the methanolysis of wood

    DOEpatents

    Steinberg, Meyer; Fallon, Peter

    1984-07-31

    A process for the production of ethylene, benzene and carbon monoxide from particulated biomass such as wood by reaction with methane at a temperature of from 700.degree. C. to 1200.degree. C., at a pressure of from 20 psi to 100 psi for a period of from 0.2 to 10 seconds.

  5. Characterization of Waste Tar Associated with Abandoned Wood Chemical Plant Sites in Northwest Pennsylvania, USA

    SciTech Connect

    Edendorn, H.M.; Severson, D.

    2007-07-01

    Over 70 wood chemical plants operated in northern Pennsylvania between ca. 1890 and 1950, all located within 72 km of the New York state border. Their original purpose was to salvage the small unwanted hardwood trees left behind by the lumber mills, and to make charcoal, calcium acetate and methanol for a number of industrial uses via destructive distillation. At many old wood chemical plant sites, unknown quantities of wood tar remain as a residual contaminant and pose a pollution threat to aquatic life in nearby streams. Research on the composition and properties of residual wood tars from five abandoned industrial sites in Pennsylvania are described. Weathered wood tars were more viscous and contained fewer volatile and semivolatile organic compounds than did soil-buried tars. Phenol, 2-methylphenol (o-cresol), 4-methylphenol (p-cresol), and 2, 4-dimethylphenol were found in all sampled tars. These water-soluble phenolic compounds were released quasi-instantaneously in aqueous solution, followed by a slower rate of release, consistent with the behavior of similar compounds in other dense non-aqueous liquids. Air-exposed wood tar deposits developed a hard crust, which contained fewer volatiles and semivolatiles and had a higher softening point than other samples. These tars eroded to form a powdered soil colonized by lichens and mosses. Residual wood tar material found at one site was shown to be thermally altered, likely during the historical destruction of the chemical plant by fire. Recovered wood tar wastes have a relatively high heating value and may have use as a potential, but limited, alternate energy source.

  6. Chemical composition and protein enrichment of orange peels and sugar beet pulp after fermentation by two Trichoderma species

    PubMed Central

    Ahmadi, F; Zamiri, M. J.; Khorvash, M; Banihashemi, Z; Bayat, A. R.

    2015-01-01

    The present experiment aimed at increasing orange peel and sugar beet pulp protein content through solid-state fermentation by Trichoderma reesei and Trichoderma viride. In vitro digestibility and changes in the chemical composition of the fermented products were determined after seven days of fungal cultivation using gas production tests. The cultivation of T. reesei and T. viride on orange peels decreased neutral detergent soluble content (P<0.01) and increased cellulose, hemicellulose and lignin contents (P<0.01). Changes in fiber fractions were found to be more pronounced with T. viride. The cultivation of T. reesei and T. viride on sugar beet pulp increased neutral detergent soluble content (P<0.01) and decreased cellulose and hemicellulose contents (P<0.01). These changes were more pronounced with T. reesei. The cultivation of T. reesei or T. viride on orange peels or sugar beet pulp increased crude protein content (P<0.01) compared with the unfermented materials; however, the increase was more pronounced for orange peels fermented with T. viride when corrected for weight loss (P<0.05). After 24 and 48 h of incubation, significant decreases in cumulative gas production (P<0.01) were observed in fermented sugar beet pulp and orange peels compared with the unfermented materials. Fungal treatment of orange peels and sugar beet pulp reduced the digestibility of in vitro organic matter, metabolizable energy and average fermentation and gas production rates (P<0.01). The data showed that seven days of solid-state fermentation of orange peels and sugar beet pulp by T. reesei or T. viride can increase their crude protein content. PMID:27175146

  7. Changes in the Chemical Composition and Decay Resistance of Thermally-Modified Hevea brasiliensis Wood.

    PubMed

    Severo, Elias Taylor Durgante; Calonego, Fred Willians; Sansígolo, Cláudio Angeli; Bond, Brian

    2016-01-01

    In this study the effect of thermal treatment on the equilibrium moisture content, chemical composition and biological resistance to decay fungi of juvenile and mature Hevea brasiliensis wood (rubber wood) was evaluated. Samples were taken from a 53-year-old rubber wood plantation located in Tabapuã, Sao Paulo, Brazil. The samples were thermally-modified at 180°C, 200°C and 220°C. Results indicate that the thermal modification caused: (1) a significant increase in the extractive content and proportional increase in the lignin content at 220°C; (2) a significant decrease in the equilibrium moisture content, holocelluloses, arabinose, galactose and xylose content, but no change in glucose content; and (3) a significant increase in wood decay resistance against both Pycnoporus sanguineus (L.) Murrill and Gloeophyllum trabeum (Pers.) Murrill decay fungi. The greatest decay resistance was achieved from treatment at 220°C which resulted in a change in wood decay resistance class from moderately resistant to resistant. Finally, this study also demonstrated that the influence of thermal treatment in mature wood was lower than in juvenile wood. PMID:26986200

  8. Changes in the Chemical Composition and Decay Resistance of Thermally-Modified Hevea brasiliensis Wood

    PubMed Central

    2016-01-01

    In this study the effect of thermal treatment on the equilibrium moisture content, chemical composition and biological resistance to decay fungi of juvenile and mature Hevea brasiliensis wood (rubber wood) was evaluated. Samples were taken from a 53-year-old rubber wood plantation located in Tabapuã, Sao Paulo, Brazil. The samples were thermally-modified at 180°C, 200°C and 220°C. Results indicate that the thermal modification caused: (1) a significant increase in the extractive content and proportional increase in the lignin content at 220°C; (2) a significant decrease in the equilibrium moisture content, holocelluloses, arabinose, galactose and xylose content, but no change in glucose content; and (3) a significant increase in wood decay resistance against both Pycnoporus sanguineus (L.) Murrill and Gloeophyllum trabeum (Pers.) Murrill decay fungi. The greatest decay resistance was achieved from treatment at 220°C which resulted in a change in wood decay resistance class from moderately resistant to resistant. Finally, this study also demonstrated that the influence of thermal treatment in mature wood was lower than in juvenile wood. PMID:26986200

  9. Size-dependent changes in wood chemical traits: a comparison of neotropical saplings and large trees

    PubMed Central

    Martin, Adam R.; Thomas, Sean C.; Zhao, Yong

    2013-01-01

    Wood anatomical traits are important correlates of life-history strategies among tree species, yet little is known about wood chemical traits. Additionally, size-dependent changes in wood chemical traits have been rarely examined, although these changes may represent an important aspect of tree ontogeny. Owing to selection for pathogen resistance and biomechanical stability, we predicted that saplings would show higher lignin (L) and wood carbon (Cconv), and lower holocellulose (H) concentrations, compared with conspecific large trees. To test these expectations, we quantified H, L and Cconv in co-occurring Panamanian tree species at the large tree vs. sapling size classes. We also examined inter- and intraspecific patterns using multivariate and phylogenetic analyses. In 15 of 16 species, sapling L concentration was higher than that in conspecific large trees, and in all 16 species, sapling H was lower than that in conspecific large trees. In 16 of 24 species, Cconv was higher in saplings than conspecific large trees. All large-tree traits were unrelated to sapling values and were unrelated to four life-history variables. Wood chemical traits did not show a phylogenetic signal in saplings, instead showing similar values across distantly related taxa; in large trees, only H showed a significant phylogenetic signal. Size-dependent changes in wood chemistry show consistent and predictable patterns, suggesting that ontogenetic changes in wood chemical traits are an important aspect of tree functional biology. Our results are consistent with the hypothesis that at early ontogenetic stages, trees are selected for greater L to defend against cellulose-decaying pathogens, or possibly to confer biomechanical stability.

  10. Evaluation of morphological and chemical aspects of different wood species by spectroscopy and thermal methods

    NASA Astrophysics Data System (ADS)

    Popescu, Maria-Cristina; Popescu, Carmen-Mihaela; Lisa, Gabriela; Sakata, Yusaku

    2011-03-01

    The aim of this study is to find the most convenient procedure to make an easy differentiation between various kinds of wood. The wood samples used were: fir (Acer alba), poplar (Populus tremula), lime (Tillia cordata), sycamore (Acer pseudoplatanus), sweet cherry (Prunus avium), hornbeam (Carpinus betulus), walnut (Juglans regia), beech (Fagus sylvatica), oak (Quercus robur). The methods of investigation used were FT-IR spectroscopy, X-ray diffraction and thermogravimetry. By FT-IR spectroscopy, was observed that the ratio values of lignin/carbohydrate IR bands for wood decreases with increasing the average wood density, showing a decrease in lignin content. Also, the calculated values of lignin percentage from the FT-IR spectra are in very good correlation with the values from literature. Following the deconvolution process of the X-ray diffraction patterns, it was found that the degree of crystallinity, the apparent lateral crystallite size, the proportion of crystallite interior chains and cellulose fraction tend to increase with increasing of the wood density. Thermal analysis is able to give information about degradation temperatures for the principal components of different wood samples. The shape of DTG curves depends on the wood species that cause the enlargement of the peaks or the maxima of the decomposition step varies at larger or smaller temperatures ranges. The temperatures and weight loss percentage are particular for each kind of wood. This study showed that analytical methods used have the potential to be important sources of information for a quick evaluation of the chemical composition of wood samples.

  11. From hazardous waste to valuable raw material: hydrolysis of CCA-treated wood for the production of chemicals.

    PubMed

    Hakola, Maija; Kallioinen, Anne; Leskelä, Markku; Repo, Timo

    2013-05-01

    Solid wood, metal finnish: Instead of burning waste wood treated with chromated copper arsenite (CCA) or disposing of it in landfills, the CCA-treated wood can be used as a raw material for the production of chemicals. Catalytic or alkaline oxidation together with very mild sulfuric acid extraction produces an easily enzymatically hydrolyzable material. Usage as a raw material for the chemical industry in this manner demonstrates a sustainable and value-added waste management process. PMID:23554264

  12. Physical and Chemical Properties of Some Imported Woods and their Degradation by Termites

    PubMed Central

    Shanbhag, Rashmi R.; Sundararaj, R.

    2013-01-01

    The influence of physical and chemical properties of 20 species of imported wood on degradation of the wood by termites under field conditions was studied. The wood species studied were: Sycamore maple, Acer pseudoplatanus L. (Sapindales: Sapindaceae) (from two countries), Camphor, Dryobalanops aromatic C.F.Gaertner (Malvales: Dipterocarpaceae), Beech, Fagus grandifolia Ehrhart (Fagales: Fagaceae), F. sylvatica L. (from two countries), Oak, Quercus robur L., Ash, Fraxinus angustifolia Vahl (Lamiales: Oleaceae), F. excelsior L., Padauk, Pterocarpus soyauxii Taubert (Fabales: Fabaceae), (from two countries), Jamba, Xylia dolabrifiormis Roxburgh, Shorea laevis Ridley (Malvales: Dipterocarpaceae), S. macoptera Dyer, S. robusta Roth, Teak, Tectona grandis L.f. (Lamiales: Lamiaceae) (from five countries), and rubber tree, Hevea brasiliensis Müller Argoviensis (Malpighiales: Euphorbiaceae) from India. The termites present were: Odontotermes horni (Wasmann) (Isoptera: Termitidae), O. feae, O. wallonensis, and O. obeus (Rambur). A significant conelation was found between density, cellulose, lignin, and total phenolic contents of the wood and degradation by termites. The higher the density of the wood, the lower the degradation. Similarly, higher amount of lignin and total phenolic contents ensured higher resistance, whereas cellulose drives the termites towards the wood. PMID:23906349

  13. Physical and chemical properties of some imported woods and their degradation by termites.

    PubMed

    Shanbhag, Rashmi R; Sundararaj, R

    2013-01-01

    The influence of physical and chemical properties of 20 species of imported wood on degradation of the wood by termites under field conditions was studied. The wood species studied were: Sycamore maple, Acer pseudoplatanus L. (Sapindales: Sapindaceae) (from two countries), Camphor, Dryobalanops aromatic C.F.Gaertner (Malvales: Dipterocarpaceae), Beech, Fagus grandifolia Ehrhart (Fagales: Fagaceae), F. sylvatica L. (from two countries), Oak, Quercus robur L., Ash, Fraxinus angustifolia Vahl (Lamiales: Oleaceae), F. excelsior L., Padauk, Pterocarpus soyauxii Taubert (Fabales: Fabaceae), (from two countries), Jamba, Xylia dolabrifiormis Roxburgh, Shorea laevis Ridley (Malvales: Dipterocarpaceae), S. macoptera Dyer, S. robusta Roth, Teak, Tectona grandis L.f. (Lamiales: Lamiaceae) (from five countries), and rubber tree, Hevea brasiliensis Müller Argoviensis (Malpighiales: Euphorbiaceae) from India. The termites present were: Odontotermes horni (Wasmann) (Isoptera: Termitidae), O. feae, O. wallonensis, and O. obeus (Rambur). A significant conelation was found between density, cellulose, lignin, and total phenolic contents of the wood and degradation by termites. The higher the density of the wood, the lower the degradation. Similarly, higher amount of lignin and total phenolic contents ensured higher resistance, whereas cellulose drives the termites towards the wood. PMID:23906349

  14. A spectrocolorimetric and chemical study on color modification of heat-treated wood during artificial weathering

    NASA Astrophysics Data System (ADS)

    Huang, Xianai; Kocaefe, Duygu; Kocaefe, Yasar; Boluk, Yaman; Pichette, Andre

    2012-05-01

    Effect of artificial weathering on the wood surface color modifications of three North American species (jack pine, aspen, and birch) heat-treated under different temperatures was studied by spectrocolorimetric colormeter (datacolor, CHECK TM). Data was analyzed using the reflectance spectra (400-700 nm) as well as the CIE-L*a*b* system and ΔE. Kubelka-Munk (K-M) spectra of samples were recorded as a function of artificial weathering time to obtain the absorption maxima of the chromophore woods formed during artificial weathering. The results were compared with those of the respective untreated (Kiln-dried) species. Analysis of chemical components shows that the lignin percent of jack pine, aspen, and birch increased after heat treatment (28.66-35.9%, 20.27-26.41%, and 19.04-22.71% respectively) which might be due to smaller influence of heat treatment on lignin content than hemicelluloses. This improves the resistance of heat-treated wood to photo-degradation. This is also supported by the smaller change observed in K-M spectra and total color parameters in CIE-L*a*b* system of heat-treated wood samples compared to those of untreated wood when weathered for72 h. However, the lignin percent of heat-treated woods reduce to maximum 2.5% after artificial weathering of 1512 h. This suggests that the weathering degrades most lignin matrix; consequently, both the colors of heat-treated woods and untreated woods are lighter and very similar after a long period of artificial weathering.

  15. Effects of thermal treatment on chemical, mechanical and colour traits in Norway spruce wood.

    PubMed

    Kačíková, Danica; Kačík, František; Cabalová, Iveta; Durkovič, Jaroslav

    2013-09-01

    In several different branches of the wood industry heat treatment is a growing application as it changes the chemical, mechanical, physical and biological properties of wood. Investigations using wet chemical analyses, Fourier transform infrared spectroscopy, size exclusion chromatography, and CIELab colour system have been conducted to study the changes in Norway spruce wood subjected to temperature up to 270°C over a 30 min time period. The results showed that mass loss (ML), total crystallinity index (TCI) of cellulose, total colour difference (ΔE*), and the content of lignin and extractives increased with the temperature, whereas degree of polymerization (DP) of cellulose, modulus of rupture (MOR), modulus of elasticity (MOE), lightness difference (ΔL*), and the content of holocellulose, cellulose and hemicelluloses all decreased with the thermal treatment. Relationships between temperature and the examined wood traits were all fitted by exponential curves. Power law relationships were found to fit the trends for DP of cellulose with ΔE*, ΔL*, and TCI of cellulose. Also found were power law regressions for the content of hemicelluloses with MOE, MOR, ΔL*, and ML. Temperatures ranging from 20 to 187°C formed a compact cluster, clearly separated from the higher examined temperatures in the multivariate wood trait space. PMID:23871194

  16. REMEDIATION OF SOILS CONTAMINATED WITH WOOD-TREATMENT CHEMICALS (PCP AND CREOSOTE)

    EPA Science Inventory

    PCP and creosote PAHs are found in most of the contaminated soils at wood-treatment sites. The treatment methods currently being used for such soils include soil washing, incineration, and biotreatment. Soil washing involves removal of the hazardous chemicals from soils ...

  17. Thermal Processing Alters the Chemical Quality and Sensory Characteristics of Sweetsop (Annona squamosa L.) and Soursop (Annona muricata L.) Pulp and Nectar.

    PubMed

    Baskaran, Revathy; Ravi, Ramasamy; Rajarathnam, Somasundaram

    2016-01-01

    The objective of this study was to investigate the effect of thermal processing on the chemical quality and sensory characteristics of Annona squamosa L. and Annona muricata L. fruit pulps and nectar. The fruit pulps were pasteurized at 85 °C for 20 min and nectar prepared as per Food Safety and Standards Authority of India (FSSAI) specifications. The chemical composition of fresh and heated pulps of A. squamosa and A. muricata showed that compared to fresh, the chemical profile and sensory profile changed in heated samples and nectar. The free and bound phenolics of A. squamosa increased in heated pulp (127.61 to 217.22 mg/100 g and 150.34 to 239.74 mg/100 g, respectively), while in A. muricata, free phenolics increased very marginally from 31.73 to 33.74 mg/100 g and bound phenolics decreased from 111.11 to 86.91 mg/100 g. This increase in phenolic content may be attributed to the perception of bitterness and astringency in A. squamosa pulp on heating. In electronic tongue studies, principal component analysis (PCA) confirmed that the fresh and heated pulps had different scores, as indicated by sensory analysis using qualitative descriptive analysis (QDA). E-tongue analysis of samples discriminated the volatile compounds released from the heated A. squamosa and A. muricata fruit pulps and nectar in their respective PCA plots by forming different clusters. PMID:26642109

  18. Development of a combined piezoresistive pressure and temperature sensor using a chemical protective coating for Kraft pulp digester process monitoring

    NASA Astrophysics Data System (ADS)

    Mohammadi, Abdolreza R.; Bennington, Chad P. J.; Chiao, Mu

    2011-01-01

    We have developed an integrated piezoresistive pressure and temperature sensor for multiphase chemical reactors, primarily Kraft pulp digesters (pH 13.5, temperatures up to 175 °C, reaching a local maximum of 180 °C and pressures up to 2 MPa). The absolute piezoresistive pressure sensor consisted of a large square silicon diaphragm (1000 × 1000 µm2) and high resistance piezoresistors (10 000 Ω). A 4500 Ω buried piezoresistive wire was patterned on the silicon chip to form a piezoresistive temperature sensor which was used for pressure sensor compensation and temperature measurement. A 4 µm thick Parylene HT® coating, a chemically resistant epoxy and a silicone conformal coating were deposited to passivate the pressure sensor against the caustic environment in Kraft digesters. The sensors were characterized up to 2 MPa and 180 °C in an environment chamber. A maximum thermal error of ±0.72% full-scale output (FSO), an average sensitivity of 0.116 mV (V kPa)-1 and a power consumption of 0.3 mW were measured in the pressure sensor. The sensors' resistances were measured before and after test in a Kraft pulping cycle and showed no change in their values. SEM pictures and topographical surfaces were also analyzed before and after pulp liquor exposure and showed no observable changes.

  19. Chemical evolution of Miocene wood: Example from the Belchatow brown coal deposit, central Poland

    USGS Publications Warehouse

    Drobniak, A.; Mastalerz, Maria

    2006-01-01

    Miocene conifer wood samples from the Belchatow brown coal deposit in Poland were studied in order to discuss a range of chemical variations that occur as a result of biochemical coalification. Petrographic analysis, ultimate analysis, electron microprobe technique, and FTIR spectroscopy were used in this study. Our data show several progressive trends in functional groups distribution that take place during the wood transformation from group 1 to group 4, such as an overall increase in aromaticity, an increase in lignin/cellulose ratio, and an increase in oxygen functionalities. Other observations include an increase in aliphatic stretching and bending functionalities from groups 1 to 3; followed by a decrease in the wood of group 4; appearance of aliphatic out-of-plane bands in group 3 and increase in group 4; an increase in CH2/CH3 in group 4 compared to the other groups; and decrease in O-H groups in group 4 compared to other groups. These observations, together with other chemical and petrological observations, indicate that the progressive elimination of cellulose and modification of lignin are dominant processes of the wood transformation. ?? 2005 Elsevier B.V. All rights reserved.

  20. Residential and biological exposure assessment of chemicals from a wood treatment plant.

    PubMed

    Dahlgren, James; Takhar, Harpreet; Schecter, Arnold; Schmidt, Reynold; Horsak, Randy; Paepke, Olaf; Warshaw, Raphael; Lee, Alexander; Anderson-Mahoney, Pamela

    2007-04-01

    This paper evaluates the results of contamination of residents and residential homes located in close proximity to a Wood Treatment Plant. The plant has produced treated wood products continuously since 1904. The principle chemicals used to treat the wood, which is primarily used for railroad ties (oblong objects laid perpendicular to the rails to act as a base for the tracks), are creosote and pentachlorophenol. For a number of years, the plant burned treated waste wood products containing creosote and pentachlorophenol. First the plant pressure impregnates the wood with creosote and pentachlorophenol, and then the wood is stacked on open ground to allow it to air dry. Chemicals from recently treated wood ties are allowed to evaporate into the air or drip onto the ground surrounding the stacked wood. Small drainage ditches carry the liquid wastes into larger water channels where eventually the waste streams are discharged into a river adjacent to the plant. The river serves as a source of drinking water for the nearby community. Prevailing wind patterns favor a drift of air emissions from the plant's boiler stack over the nearby community and its residents. Over the past few years, the town's residents have become increasingly concerned about their health status and have voiced concerns regarding multiple health problems (including cancer), possibly associated with plant discharges. The intention of this study is to examine a representative sample of the potentially affected residents and to evaluate their residential environment for the presence of dioxin and/or its congeners. Data obtained from EPA's Toxic Release Information (TRI) database revealed the plant routinely discharged creosote, pentachlorophenol, dioxin and dioxin-like compounds into the ambient air via fugitive air emissions and surface waste waters. Sampling of household dust and water sediment within and outside of residences within a 2-mile radius of the plant revealed the presence of

  1. [Vegetable resources with agroindustrial potential from Guatemala. Chemical characterization of the pulp and of the seeds of Theobroma bicolor].

    PubMed

    Furlán, A L; Bressani, R

    1999-12-01

    T. bicolor grows wild in certain regions of Guatemala. The fruit is utilized by the rural population for the preparation of drinks from the pulp and the seed, replacing cocoa (T. cocoa). The fruit of T. bicolor used in the present study, measured on the average, 15 cm long and had an average weight, of 752 g. The pulp, the shell, and the seed represented 23.8, 62.5, and 13.7%, respectively, of the fruit weight. The pulp contained on the average, 38 seeds/fruit, which weighted on the average, 1.11 g and were 2.4 cm long. T. cacao seeds weighted 0.62 g and were 1.6 cm long. The protein content (24.42%) and fiber content (30.86%) of the T. bicolor seeds, was greater than those from T. cacao, although fat content was lower (25.48%). The fat of the seeds of T. bicolor has different physicochemical characteristics than the fat of the seeds of T. cacao, such as melting point, iodine value, and saponification number. The seeds of both, T. cacao and T. bicolor, were used for the preparation of a local drink using toasted corn flour, sugar, and anatto flour in equal preparations, with and without toasted whole soybean flours (6.25%). Through a sensory ranking trial, it is established that the drink from T. bicolor and soybeans, was preferred over other preparations with T. cacao. The pulp of T. bicolor with an interesting chemical composition, yielded an aromatic pleasant drink, and from T. bicolor, is an interesting resource for industrialization and for genetic characteristics for T. cacao improvement. PMID:10883304

  2. Chemical Composition, Antioxidant, and Antibacterial Activity of Wood Vinegar from Litchi chinensis.

    PubMed

    Yang, Jyh-Ferng; Yang, Cheng-Hong; Liang, Ming-Tsai; Gao, Zi-Jie; Wu, Yuh-Wern; Chuang, Li-Yeh

    2016-01-01

    The antioxidant and antibacterial activities of wood vinegar from Litchi chinensis, and its components have been studied. The chemical compositions of wood vinegar were analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 17 chemical compounds were identified, representing 83.96% of the compositions in the wood vinegar. Three major components, included 2,6-dimethoxyphenol (syringol, 29.54%), 2-methoxyphenol (guaiacol, 12.36%), and 3,5-dimethoxy-4-hydroxytoluene (11.07%), were found in the wood vinegar. Antioxidant activities of the acids were investigated from the aspects of 1,1-Diphyl-2-picrylhydrazyl (DPPH) free radicals scavenging capacity, superoxide anion radical scavenging capacity, and reducing power. The pyroligneous acid exhibited high antioxidant activity which was comparable to the reference standards (vitamin C and butylated hydroxyl toluene) at the same dose with IC50 values of 36.5 ppm calculated by the DPPH radical scavenging assay, 38.38 g Trolox equivalent/100 g DW by the trolox equivalent antioxidant capacity (TEAC) assay, and 67.9 by the reducing power analysis. Antibacterial activity was evaluated using the disc diffusion and microdilution methods against a group of clinically antibiotic resistant isolates. The major components exhibited broad spectrum inhibition against all the bacterial strains with a range of disc inhibition zoon between 15-19 mm. The minimum inhibition concentration and minimum bactericide concentration against the test strains was ranging in 0.95-3.80 μL/100 μL and 1.90-3.80 μL/100 μL, respectively. Most of the antibiotic resistant strains were more susceptible to the wood vinegar than the non-antibiotic resistant strain except the strain of ornithine resistant Staphylococcus aureus. Based on the chemical profile, it was considered that the strongest antioxidant and antibacterial activity of Litchi chinensis wood vinegar was due to its highly phenolic compositions. This study revealed that the Litchi

  3. Physico-chemical characterization of alkaline soluble polysaccharides from sugar beet pulp

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have studied the global structure of microwave-assisted alkaline soluble polysaccharides (ASP) isolated from fresh sugar beet pulp. The objective was to minimize the disassembly and possibly the degradation of these polysaccharides during extraction. Prior to ASP microwave assisted-extraction (...

  4. Physico-chemical characterization of protein associated polysaccharides extracted from sugar beet pulp

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugar Beet Pulp (SBP), contains 67 to 80% (dry weight) of potentially valuable polysaccharides. We have solubilized and separated polysaccharides from SBP into three fractions with steam assisted flash extraction (SAFE) employed to solubilize the first and second fractions. Pectin, the first fract...

  5. Converting waste gases from pulp mills into value-added chemicals

    EPA Science Inventory

    Engineering, Miami University, 64 J Engineering Building, Oxford, OH, 45056 The pulp and paper industry generates large amounts of HAPs, VOCs and total reduced sulfur compounds (TRSs) of the various sources. As the industry is moving to a sustainable future, the U.S. EPA and Mia...

  6. Physico-chemical characterization of a cellulosic fraction from sugar beet pulp

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The residue of sugar beet pulp from which pectin and alkaline soluble polysaccharides have been removed by microwave assisted extraction (MAE) or conventional heat was treated with sodium monochloroacetate under alkaline pH to convert the residual cellulose present to carboxy methyl cellulose (CMC)....

  7. Chemical methods in the development of eco-efficient wood-based pellet production and technology.

    PubMed

    Kuokkanen, Matti; Kuokkanen, Toivo; Stoor, Tuomas; Niinimäki, Jouko; Pohjonen, Veli

    2009-09-01

    Up to 20 million tons of waste wood biomass per year is left unused in Finland, mainly in the forests during forestry operations, because supply and demand does not meet. As a consequence of high heat energy prices, the looming threat of climate change, the greenhouse effect, and due to global as well as national demands to considerably increase the proportion of renewable energy, there is currently tremendous enthusiasm in Finland to substantially increase pellet production. As part of this European objective to increase the eco- and cost-efficient utilization of bio-energy from the European forest belt, the aim of our research group is - by means of multidisciplinary research, especially through chemical methods - to promote the development of Nordic wood-based pellet production in both the qualitative and the quantitative sense. Wood-based pellets are classified as an emission-neutral fuel, which means that they are free from emission trading in the European Union. The main fields of pellet research and the chemical toolbox that has been developed for these studies, which includes a new specific staining and optical microscope method designed to determine the cross-linking of pellets in the presence of various binding compounds, are described in this paper. As model examples illustrating the benefits of this toolbox, experimental data is presented concerning Finnish wood pellets and corresponding wood-based pellets that include the use of starch-containing waste potato peel residue and commercial lignosulfonate as binding materials. The initial results concerning the use of the developed and optimized specific staining and microscopic method using starch-containing potato peel residue as binding material are presented. PMID:19470536

  8. Direct chemical characterization of natural wood resins by temperature-resolved and space-resolved Fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, Jian-bo; Zhou, Qun; Sun, Su-qin

    2016-07-01

    Wood resins are valuable natural products with wide utilizations. Either in the form of resin exudates or in the form of resin-containing woods, natural wood resins are usually complex mixtures consisting of various compounds. Therefore, effective chemical characterization methods are necessary for the research and quality control of natural wood resins. No need for separation or labeling, wood resin samples can be measured directly by Fourier transform infrared (FT-IR) spectroscopy, which reduces the testing costs and avoids the possible distortions caused by the pretreatments. However, the absorption bands of various compositions in the resin sample are assembled in a single spectrum by the separation-free measurement, which makes it difficult to identify the compounds of interest and decreases the limits of detection. In this research, the temperature-resolved and space-resolved FT-IR techniques are proposed to resolve the overlapped signals for the direct, selective, and sensitive characterization of natural wood resins. For resin exudates, the temperature-resolved FT-IR spectroscopy and two-dimensional correlation analysis can resolve the absorption bands of different compounds according to their responses to the thermal perturbations. For resin-containing woods, the FT-IR microspectroscopic imaging and principal component analysis can resolve the absorption bands of different compounds according to their positions. The study of six kinds of wood resins proves the feasibility of temperature-resolved and space-resolved FT-IR techniques for the direct, selective, and sensitive chemical characterization of natural wood resins.

  9. Biological modification of loblolly pine chips with Ceriporiopsis subvermispora prior to kraft pulping

    NASA Astrophysics Data System (ADS)

    Villalba, Laura L.

    The ability of the white-rot fungus Ceriporiopsis subvermispora to selectively degrade lignin in loblolly pine chips and the effect on kraft pulps was investigated. The effect of fungal treatment was assessed by comparing changes in untreated wood chips with chips incubated for two and four weeks. The kraft pulping step included two different cooking times and two levels of chemical dosage as the variables, 16 and 22% for the effective alkali and 60 and 90 min at 170°C. The other cooking variables were kept constant for all the experiments and were: sulfidity, 22%; liquor/wood ratio 4:1; time to Tmax 90 min.; Tmax 170°C. Scanning electron microscopy (SEM) revealed that the colonization introduced significant chemical and physical changes. Pore size distribution analyses revealed a statistically significant increase in the average pore size as fungal treatment progressed. Significant reduction in the extractives content (23%) was found in the first 2 weeks, after which the reduction leveled off. Lignin losses reached 2% in the first 2 weeks of incubation, followed by an 11% loss after 4 weeks of treatment. Lignin phenolic hydroxyl groups increased 14% after 4 weeks of incubation. Fungal treatment caused 4 and 6% carbohydrate loss in 2 and 4 weeks-treated chips, respectively. The selectivity of the fungal treatment was emphasized in the subsequent kraft pulping. The best response regarding improved delignification was found in kraft pulps processed at the mildest pulping conditions without affecting pulp viscosity. Benefits of fungal treatment regarding freeness of kraft pulps were evidenced after 4 weeks of incubation with a maximum of 35% freeness reduction in kraft pulps refined at 12,000 rev in a PFI mill. Strength properties of kraft pulps of fungal treated chips were superior to those of the control. This method involves chemical and physical modification of wood chips using fungi. The approach improved chip impregnation, which in turn, led to more uniform

  10. Size-dependent changes in leaf and wood chemical traits in two Caribbean rainforest trees.

    PubMed

    Martin, Adam R; Thomas, Sean C

    2013-12-01

    Tree functional traits and their link to patterns of growth and demography are central to informing trait-based analyses of forest communities, and mechanistic models of forest dynamics. However, few data are available on how functional traits in trees vary through ontogeny, particularly in tropical species; and less is known about how patterns of size-dependent changes in traits may differ across species of contrasting life-history strategies. Here we describe size-dependent variation in seven leaf functional traits and four wood chemical traits, in two Dominican rainforest tree species (Dacryodes excelsa Vahl. and Miconia mirabilis (Aubl.) L.O. Williams), ranging from small saplings to the largest canopy trees. With one exception, all traits showed pronounced variation with tree size (diameter at breast height, DBH). Leaf mass per area (LMA), thickness and tissue density increased monotonically with DBH in both species. Leaf area, leaf nitrogen (N) and carbon (C) : nitrogen (N) ratios also varied significantly with DBH; however, these patterns were unimodal, with peak trait values preceding the DBH at reproductive onset in both species. Size-dependent changes in leaf structural traits (LMA and leaf thickness) were generally similar in both species, while traits associated with leaf-level investment in C gain (leaf area, leaf C : N ratio) showed contrasting ontogenetic trends between species. Wood starch concentration varied with DBH in both species, also showing unimodal patterns with peaks preceding size at reproductive onset. Wood C concentration increased linearly with DBH in both species, though significantly only in M. mirabilis. Size-dependent patterns in wood chemical traits were similar between both species. Our data demonstrate pronounced variation in functional traits through tree ontogeny, probably due to a combination of environmental factors and shifts in resource allocation. Such ontogenetic variation is comparable in magnitude with interspecific

  11. Isolation and chemical identification of lipid derivatives from avocado (Persea americana) pulp with antiplatelet and antithrombotic activities.

    PubMed

    Rodriguez-Sanchez, Dariana Graciela; Flores-García, Mirthala; Silva-Platas, Christian; Rizzo, Sheryl; Torre-Amione, Guillermo; De la Peña-Diaz, Aurora; Hernández-Brenes, Carmen; García-Rivas, Gerardo

    2015-01-01

    Platelets play a pivotal role in physiological hemostasis. However, in coronary arteries damaged by atherosclerosis, enhanced platelet aggregation, with subsequent thrombus formation, is a precipitating factor in acute ischemic events. Avocado pulp (Persea americana) is a good source of bioactive compounds, and its inclusion in the diet as a source of fatty acid has been related to reduced platelet aggregability. Nevertheless, constituents of avocado pulp with antiplatelet activity remain unknown. The present study aims to characterize the chemical nature of avocado constituents with inhibitory effects on platelet aggregation. Centrifugal partition chromatography (CPC) was used as a fractionation and purification tool, guided by an in vitro adenosine diphosphate (ADP), arachidonic acid or collagen-platelet aggregation assay. Antiplatelet activity was initially linked to seven acetogenins that were further purified, and their dose-dependent effects in the presence of various agonists were contrasted. This process led to the identification of Persenone-C (3) as the most potent antiplatelet acetogenin (IC₅₀=3.4 mM) among the evaluated compounds. In vivo evaluations with Persenone A (4) demonstrated potential protective effects against arterial thrombosis (25 mg kg⁻¹ of body weight), as coagulation times increased (2-fold with respect to the vehicle) and thrombus formation was attenuated (71% versus vehicle). From these results, avocado may be referred to as a functional food containing acetogenin compounds that inhibit platelet aggregation with a potential preventive effect on thrombus formation, such as those that occur in ischaemic diseases. PMID:25319210

  12. Soda-anthraquinone pulping of palm oil empty fruit bunches and beating of the resulting pulp.

    PubMed

    Jiménez, L; Serrano, L; Rodríguez, A; Sánchez, R

    2009-02-01

    The influence of soda-anthraquinone pulping variables (temperature, time and soda concentration) and beating (number of PFI beating revolution) of palm oil empty fruit bunches (EFB) on the resulting paper sheets was studied, with a view to identifying the optimum operating conditions. Equations were derived that reproduced the properties of the paper sheets with errors less than 10-12% in 90-95% of cases. An optimum compromise was found as regards operating conditions (15% soda, 170 degrees C, 70 min and 2400 number of PFI beating revolutions) that provided paper properties departing by less than 12% from their optimum values (59.63 Nm/g tensile index, 4.48% stretch, 4.17 kN/g burst index and 7.20 m Nm(2)/g tear index), and a beating grade of 47.5 degrees SR, acceptable to obtain paper sheets. Because these conditions involve a lower soda, temperature, time and beating than those required to maximize the studied paper properties, they can save chemical reagents, energy and immobilized capital for industrial facilities. On the other hand, the stretch properties of these pulp beaten are higher than those of others non-wood pulps, as wheat straw and olive wood. PMID:18815028

  13. Biological Kraft Chemical Recycle for Augmentation of Recovery Furnace Capacity

    SciTech Connect

    Stuart E. Strand

    2001-12-06

    The chemicals used in pulping of wood by the kraft process are recycled in the mill in the recovery furnace, which oxidizes organics while simultaneously reducing sulfate to sulfide. The recovery furnace is central to the economical operation of kraft pulp mills, but it also causes problems. The total pulp production of many mills is limited by the recovery furnace capacity, which cannot easily be increased. The furnace is one of the largest sources of air pollution (as reduced sulfur compounds) in the kraft pulp mill.

  14. Electrodialysis field test for selective chloride removal from the chemical recovery cycle of a kraft pulp mill

    SciTech Connect

    Rapp, H.J.; Pfromm, P.H.

    1998-12-01

    Chloride accumulation is a serious issue in the kraft pulping process. Chloride can be selectively removed from dissolved electrostatic precipitator dust (ESP dust) in the kraft chemical recovery cycle by electrodialysis with monovalent-selective anion-exchange membranes. In a pilot-scale field test, this process was investigated (total run time, 750 h). The test was performed at about 3.5% of full scale. The process showed outstanding performance and no significant membrane fouling. In feed-and-bleed operation, chloride removal levels of 94% and 61% were tested. The energy consumption for electrodialysis is low (120 kWh per metric ton of chloride removed at a 63% chloride removal level). The process performed very well even with no feed pretreatment, polarity reversal, or membrane cleaning.

  15. Agricultural land application of pulp and paper mill sludges in the Donnacona area, Quebec: Chemical evaluation and crop response

    SciTech Connect

    Veillette, A.X.; Tanguay, M.G.

    1997-12-31

    Primary paper mill sludges from a thermomechanical pulp (TMP) mill were land applied at the rate of 20 metric ton per hectare (t/ha) for agricultural purposes in the Donnacona area, Quebec, in May 1994 and May 1995. Eleven agricultural sites featuring various crops were tested over two seasons to measure the impact of TMP primary paper mill sludges on soil, plant tissue and crop yield. Cereal and potato crops showed a significant increase in yield. TMP Primary sludges were also applied at the rate of 225 t/ha for land reclamation purposes of one site at the end of 1994. Soils were tested every second month. Chemical crop analyses were also performed. The first year crop response was satisfactory. Combined (primary and secondary) TMP sludges were added at the rate of 200 t/ha in the beginning of 1996. Soil, vadose zone water and crop analysis are being investigated. Impressive crop responses were obtained in the 1996 season.

  16. Effect of lime and wood ash on the nixtamalization of maize and tortilla chemical and nutritional characteristics.

    PubMed

    Pappa, María Renée; de Palomo, Patricia Palacios; Bressani, Ricardo

    2010-06-01

    The objective of the study was to obtain information on the chemical composition, functional properties, sensory quality and protein value of tortillas made from the nixtamalization of maize using either lime or wood ashes. The Ca, K, Mg, Fe, and Zn content of lime and wood ashes showed lime to be high in Ca content while wood ash contained more K and about 71% of the Ca content of lime. Both contained relatively high levels of Mg, Fe and Zn, but more so in the wood ashes. The level of reagent for nixtamalization was set at 0.8% of the maize weight. All other processing conditions were kept constant. The pH of the cooking solution was 12.0 for lime and 10.9 for wood ash. The moisture content of maize at 60 min of cooking was 45.8% for both treatments, however after 12 h of soaking, moisture level was 51.0% for the lime treatment and only 46.8% for the ash treatment. Solids (2.4%) in the lime cooking liquor were higher than in the wood ash liquor (1.0%). Chemical composition changes were similar between treatments in masa and tortilla; however, both masa and tortillas absorbed relatively high levels of all minerals including Fe and Zn from the wood ash treatment. The different treatment influenced functional properties particularly hardness and color. Tortilla characteristics were also similar. Protein quality of both alkali cooked products was lower than that of raw corn, more so the product from the wood ash treatment. Although some differences were observed in the sensory studies, human subjects did not dislike the wood ash made tortillas. PMID:20369297

  17. Chemical Speciation and Bioaccessibility of Arsenic and Chromiumin Chromated Copper Arsenate-Treated Wood and Soils

    SciTech Connect

    Nico, Peter S.; Ruby, Michael V.; Lowney, Yvette W.; Holm,Stewart E.

    2005-10-12

    This research compares the As and Cr chemistry ofdislodgeable residues from Chromated Copper Arsenate (CCA)-treated woodcollected by two different techniques (directly from the board surfaceeither by rubbing with a soft bristle brush or from human hands aftercontact with CCA-treated wood), and demonstrates that these materials areequivalent in terms of the chemical form and bonding of As and Cr and interms of the As leaching behavior. This finding links the extensivechemical characterization and bioavailability testing that has been donepreviously on the brush-removed residue to a material that is derivedfrom human skin contact with CCA-treated wood. Additionally, thisresearch characterizes the arsenic present in biological fluids (sweatand simulated gastric fluid) following contact with these residues. Thedata demonstrate that in biological fluids, the arsenic is presentprimarily as free arsenate ions.Arsenic-containing soils were alsoextracted into human sweat to evaluate the potential for arsenicdissolution from soils at the skin surface. For soils from field sites,only a small fraction of the total arsenic is soluble in sweat. Based oncomparisons to reference materials that have been used in in vivo dermalabsorption studies, these findings suggest that the actual relativebioavailability via dermal absorption of As from CCA-residues and soilmay be well below the current default value of 3 percent used by U.S.EPA.

  18. Health hazards of natural and introduced chemical components of boatbuilding woods.

    PubMed

    Jagels, R

    1985-01-01

    The major components of untreated wood--cellulose, hemicellulose, and lignin--have not been implicated as toxicants, but extractive substances, especially in heartwood, can be toxic. Decay-resistant woods are more likely to contain irritants or sensitizers than nondurable woods. Short-term exposures to certain wood dusts may result in asthma, conjunctivitis, rhinitis, or allergic dermatitis, but long-term effects may include nasal cancer and Hodgkin's disease. Some thermophilic microorganisms found in wood are human pathogens, and septic splinters (chromomycosis) and inhalation of ascomycete spores from stored wood chips have been implicated in human illnesses. Reconstituted wood can contain formaldehyde resins, which pose health risks in enclosed humid areas. Pentachlorophenol (PCP)-treated wood is particularly toxic--short-term exposures to PCP-treating solutions can lead to aplastic anemia and mortality, while diseases such as Hodgkin's disease are associated with long-term exposures. Since much commercial lumber is dipped in PCP, the separation of the chronic effects of wood dust from PCP exposure is difficult. Chromated copper arsenate (CCA)- and ammoniacal copper arsenite (ACA)-treated wood may leach arsenic. CCA-treated wood is potentially safer, since it contains the pentavalent arsenic, which is a common constituent in the environment. ACA contains the trivalent arsenic, which is more toxic. PMID:3901739

  19. Steam System Opportunity Assessment for the Pulp and Paper, Chemical Manufacturing, and Petroleum Refining Industries: Main Report and Appendices (CD-ROM)

    SciTech Connect

    Not Available

    2002-10-01

    The main report on this CD assesses steam generation and use in the pulp and paper, chemical, and petroleum refining industries, and estimates the potential for energy savings from implementation of steam system performace and efficiency improvements. The Appendices on this CD provide supporting information for the analyses and provides and recommendations for assessing the effectiveness of the U.S. Department of Energy BestPractices Steam Program.

  20. Carbon emissions reduction potential in the US chemicals and pulp and paper industries by applying CHP technologies

    SciTech Connect

    Khrushch, M.; Worrell, E.; Price, L.; Martin, N.; Einstein, D.

    1999-07-01

    The chemical and the pulp/paper industries combined provide 55% of CHP generation in the US industry. Yet, significant potential for new CHP capacities exists in both industries. From the present steam consumption data, the authors estimate about 50 GW of additional technical potential for CHP in both industries. The reduced carbon emissions will be equivalent to 44% of the present carbon emissions in these industries. They find that most of the carbon emissions reductions can be achieved at negative costs. Depending on the assumptions used in calculations, the economic potential of CHP in these industries can be significantly lower, and carbon emissions mitigation costs can be much higher. Using sensitivity analyses, they determine that the largest effect on the CHP estimate have the assumptions in the costs of CHP technology, in the assumed discount rates, in improvements in efficiency of CHP technologies, and in the CHP equipment depreciation periods. Changes in fuel and electricity prices and the growth in the industries' steam demand have less of an effect. They conclude that the lowest carbon mitigation costs are achieved with the CHP facility is operated by the utility and when industrial company that owns the CHP unit can sell extra electricity and steam to the open wholesale market. Based on the results of the analyses they discuss policy implications.

  1. Natural Populations of Shipworm Larvae Are Attracted to Wood by Waterborne Chemical Cues

    PubMed Central

    Toth, Gunilla B.; Larsson, Ann I.; Jonsson, Per R.; Appelqvist, Christin

    2015-01-01

    The life cycle of many sessile marine invertebrates includes a dispersive planktonic larval stage whose ability to find a suitable habitat in which to settle and transform into benthic adults is crucial to maximize fitness. To facilitate this process, invertebrate larvae commonly respond to habitat-related chemical cues to guide the search for an appropriate environment. Furthermore, small-scale hydrodynamic conditions affect dispersal of chemical cues, as well as swimming behavior of invertebrate larvae and encounter with potential habitats. Shipworms within the family Teredinidae are dependent on terrestrially derived wood in order to complete their life cycle, but very little is known about the cues and processes that promote settlement. We investigated the potential for remote detection of settling substrate via waterborne chemical cues in teredinid larvae through a combination of empirical field and laboratory flume experiments. Natural populations of teredinid larvae were significantly more abundant close to wooden structures enclosed in plankton net compared to empty control nets, clearly showing that shipworm larvae can sense and respond to chemical cues associated with suitable settling substrate in the field. However, the flume experiments, using ecologically relevant flow velocities, showed that the boundary layer around experimental wooden panels was thin and that the mean flow velocity exceeded larval swimming velocity approximately 5 mm (≈ 25 larval body lengths) from the panel surface. Therefore, we conclude that the scope for remote detection of waterborne cues is limited and that the likely explanation for the higher abundance of shipworm larvae associated with the wooden panels in the field is a response to a cue during or after attachment on, or very near, the substrate. Waterborne cues probably guide the larva in its decision to remain attached and settle, or to detach and continue swimming and drifting until the next encounter with a solid

  2. Assessment of local wood species used for the manufacture of cookware and the perception of chemical benefits and chemical hazards associated with their use in Kumasi, Ghana

    PubMed Central

    2012-01-01

    Background Historical proven wood species have no reported adverse health effect associated with its past use. Different historical proven species have traditionally been used to manufacture different wooden food contact items. This study uses survey questionnaires to assess suppliers’, manufacturers’, retailers’ and consumers’ (end-users’) preferences for specific wood species, to examine the considerations that inform these preferences and to investigate the extent of awareness of the chemical benefits and chemical hazards associated with wooden food contact material use. Methods Through the combined use of a cross sectional approach and a case study design, 25 suppliers, 25 manufacturers, 25 retailers and 125 consumers (end-users) of wooden food contact materials in four suburbs in Kumasi Metropolitan Area (Anloga junction, Ahinsan Bus Stop, Ahwia-Pankrono and Race Course) and Ashanti Akyim Agogo in the Ashanti Akyim North District of the Ashanti Region were administered with closed ended questionnaires. The questionnaires were prepared in English, but local language, Twi, was used to translate and communicate the content of the questionnaire where necessary. Results Suppliers’, manufacturers’ and retailers’ preferences for specific wood species for most wooden cookware differed from that of consumers (end-users). But all respondent groups failed to indicate any awareness of chemical benefits or chemical hazards associated with either the choice of specific wood species for specific wooden cookware or with the general use of wooden food contact materials. The lack of appreciation of chemical benefits or hazards associated with active principles of wooden cookware led to heavy reliance of consumers (end-users) on the wood density, price, attractive grain pattern and colour or on the judgement of retailers in their choice of specific species for a wooden cookware. Conclusion This study contributes some practical suggestions to guide national policy

  3. Effects of six chemical deicers on larval wood frogs (Rana sylvatica).

    PubMed

    Harless, Meagan L; Huckins, Casey J; Grant, Jacqualine B; Pypker, Thomas G

    2011-07-01

    Widespread and intensive application of road deicers, primarily road salt (NaCl), in North America threatens water quality and the health of freshwater ecosystems. Intensive use of NaCl can be harmful to sensitive members of freshwater ecosystems such as amphibians. Detection of negative effects of NaCl application has prompted the search for alternative chemical deicers with lower environmental impacts. We conducted a series of 96-h acute toxicity tests to determine the negative sensitivity of larval wood frogs (Rana [Lithobates] sylvatica) to six deicing chemicals: urea (CH(4) N(2) O), sodium chloride (NaCl), magnesium chloride (MgCl(2) ), potassium acetate (CH(3) COOK), calcium chloride (CaCl(2) ), and calcium magnesium acetate (C(8) H(12) CaMgO(8) ). Acetates are sometimes touted as environmentally friendly alternatives to NaCl but have not been examined in enough detail to warrant this designation. When exposed to a range of environmentally realistic concentrations of these chemicals, larvae were least sensitive (i.e., had the lowest mortality rate) to CH(4) N(2) O, NaCl, and MgCl(2) and most sensitive to acetates (C(8) H(12) CaMgO(8) , CH(3) COOK) and CaCl(2) . Our observed median lethal concentration estimates (LC50(96-h) ) for NaCl were over two times higher than values presented in previous studies, which suggests variability in tolerance among R. sylvatica populations. The deicers varied greatly in their toxicity, and further research is warranted to examine the differential effects of this suite of deicers on other species. PMID:21472773

  4. Draft standards and guidelines for the land application of mechanical pulp mill sludge to agricultural land

    SciTech Connect

    1998-09-01

    Mechanical pulp mill sludge consists primarily of water, wood fiber, biomass, and residual chemicals. Research has shown that application of sludge to land improves the nutrient status and physical properties of soil, resulting in enhanced plant growth. This report presents guidelines for operations involving the application of mechanical pulp mill sludge on agricultural land in Alberta. It lists the regulatory requirements for sludge generators, restrictions on land application, and record-keeping and reporting requirements; provides general information on sludge properties and parameters of interest, suitability of receiving soils and areas, and sludge application rates and frequencies. Research studies conducted in Alberta on the benefits of land application of mechanical pulp mill sludge are also summarized.

  5. Chemical, ultrastructural and supramolecular analysis of tension wood in Populus tremula x alba as a model substrate for reduced recalcitrance

    SciTech Connect

    Foston, Marcus B; Hubbell, Christopher A; Samuel, Reichel; Jung, Seung-Yong; Ding, Shi-You; Zeng, Yining; Jawdy, Sara; Sykes, Virginia R; Tuskan, Gerald A; Kalluri, Udaya C; Ragauskas, Arthur J

    2011-01-01

    Biomass is one of the most abundant potential sustainable sources for fuel and material production, however to fully realize this potential an improved understanding of lignocellulosic recalcitrance must be developed. In an effort to appreciate the underlying phenotypic, biochemical and morphological properties associated with the reduced recalcitrance observed in tension stress-induced reaction wood, we report the increased enzymatic sugar yield and corresponding chemical and ultrastructural properties of Populus tension wood. Populus tremula x alba (PTA) was grown under tension and stem segments containing three different wood types: normal wood (NW), tension wood (TW) from the elongated stem side and opposite wood (OW) from the compressed stem side were collected. A variety of analytical techniques were used to describe changes occurring as a result of the tension stress-induced formation of a gelatinous cell wall layer (G-layer). For example, gel permeation chromatography (GPC) and 13C solid-state nuclear magnetic resonance (NMR) revealed that the molecular weight and crystallinity of cellulose in TW is greater than that of cellulose acquired from NW. Whole cell ionic liquid and other solid-state NMR analysis detailed the structure of lignin and hemicellulose in the samples, detecting the presence of variations in lignin and hemicellulose sub-units, linkages and semi-quantitatively estimating the relative amounts of syringyl (S), guaiacyl (G) and p-hydroxybenzoate (PB) monolignol units. It was confirmed that TW displayed an increase in PB or H-like lignin and S to G ratio from 1.25 to 1.50 when compared to the NW sample. Scanning electron microscopy (SEM) and coherent anti-Stokes Raman scattering (CARS) were also used to evaluate the morphology and corresponding spatial distribution of the major lignocellulosic components. We found changes in a combination of cell wall properties appear to influence recalcitrance more than any single factor alone.

  6. Changes in structural and chemical components of wood delignified by fungi

    SciTech Connect

    Blanchette, R.A.; Otjen, L.; Effland, M.J.; Eslyn, W.E.

    1985-01-01

    Cerrena unicolor, Ganoderma applanatum, Ischnoderma resinosum and Poria medulla-panis were associated with birch (Betula papyrifera) wood that had been selectively delignified in the forest. Preferential lignin degradation was not uniformly distributed throughout the decayed wood. A typical white rot causing a simultaneous removal of all cell wall components was also present. In the delignified wood, 95 to 98% of the lignin was removed as well as substantial amounts of hemicelluloses. Scanning and transmission electron microscopy were used to identify the micromorphological and ultrastructural changes that occurred in the cells during degradation. In delignified areas the compound middle lamella was extensively degraded causing a defibration of cells. The secondary wall, especially the S2 layer, remained relatively unaltered. In simultaneously white-rotted wood all cell wall layers were progressively removed from the lumen toward the middle lamella causing erosion troughs or holes to form. Large voids filled with fungal mycelia resulted from a coalition of degraded areas. Birch wood decayed in laboratory soil-block tests was also intermittently delignified, selective delignification, sparsely distributed throughout the wood, and a simultaneous rot resulting in the removal of all cell wall components were evident. SEM appears to be an appropriate technique for examining selectively delignified decayed wood. 30 references.

  7. 7 CFR 160.10 - Sulphate wood turpentine.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Sulphate wood turpentine. 160.10 Section 160.10... STANDARDS FOR NAVAL STORES General § 160.10 Sulphate wood turpentine. The designation “sulphate wood... in the sulphate process of cooking wood pulp, and commonly known as sulphate turpentine or...

  8. 7 CFR 160.10 - Sulphate wood turpentine.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Sulphate wood turpentine. 160.10 Section 160.10... STANDARDS FOR NAVAL STORES General § 160.10 Sulphate wood turpentine. The designation “sulphate wood... in the sulphate process of cooking wood pulp, and commonly known as sulphate turpentine or...

  9. 7 CFR 160.10 - Sulphate wood turpentine.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Sulphate wood turpentine. 160.10 Section 160.10... STANDARDS FOR NAVAL STORES General § 160.10 Sulphate wood turpentine. The designation “sulphate wood... in the sulphate process of cooking wood pulp, and commonly known as sulphate turpentine or...

  10. 7 CFR 160.10 - Sulphate wood turpentine.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Sulphate wood turpentine. 160.10 Section 160.10... STANDARDS FOR NAVAL STORES General § 160.10 Sulphate wood turpentine. The designation “sulphate wood... in the sulphate process of cooking wood pulp, and commonly known as sulphate turpentine or...

  11. 7 CFR 160.10 - Sulphate wood turpentine.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Sulphate wood turpentine. 160.10 Section 160.10... STANDARDS FOR NAVAL STORES General § 160.10 Sulphate wood turpentine. The designation “sulphate wood... in the sulphate process of cooking wood pulp, and commonly known as sulphate turpentine or...

  12. Effect of temperature-controlled fermentation on physico-chemical properties and lactic acid bacterial count of durian (Durio zibethinus Murr.) pulp.

    PubMed

    Wasnin, Ramdiah M; Karim, Muhammad Shahrim Abdul; Ghazali, Hasanah Mohd

    2014-11-01

    Effects of controlled-temperature fermentation on several physico-chemical properties, lactic acid bacteria (LAB) counts and aroma of durian pulp were examined by storing fresh durian pulp was mixed with 2 % (w/w) salt and stored at 15 °C, 27 °C and 40 °C for 10 days. Storage at 15 °C did not affect the properties of the pulp much. However, at 27 °C and 40 °C, pH and total soluble solids decreased up to 60 % and 52 %, respectively, with greater losses at 27 °C. Titratable acidity, which increased at 27 °C, was due to lactic and acetic acids formation. Loss of sucrose and increases in glucose were greater at 27 °C. LAB population increased up to Day 3 of storage, and then decreased slightly. Principal component analysis based on aroma examination using a zNose(TM) showed better retention of aroma profile at 27 °C. Overall, durian fermented at 27 °C was more acceptable than the one prepared at 40 °C, and it is ready to be consumed between Day 4 and 6. PMID:26396291

  13. Optical and chemical characterization of aerosols emitted from coal, heavy and light fuel oil, and small-scale wood combustion.

    PubMed

    Frey, Anna K; Saarnio, Karri; Lamberg, Heikki; Mylläri, Fanni; Karjalainen, Panu; Teinilä, Kimmo; Carbone, Samara; Tissari, Jarkko; Niemelä, Ville; Häyrinen, Anna; Rautiainen, Jani; Kytömäki, Jorma; Artaxo, Paulo; Virkkula, Aki; Pirjola, Liisa; Rönkkö, Topi; Keskinen, Jorma; Jokiniemi, Jorma; Hillamo, Risto

    2014-01-01

    Particle emissions affect radiative forcing in the atmosphere. Therefore, it is essential to know the physical and chemical characteristics of them. This work studied the chemical, physical, and optical characteristics of particle emissions from small-scale wood combustion, coal combustion of a heating and power plant, as well as heavy and light fuel oil combustion at a district heating station. Fine particle (PM1) emissions were the highest in wood combustion with a high fraction of absorbing material. The emissions were lowest from coal combustion mostly because of efficient cleaning techniques used at the power plant. The chemical composition of aerosols from coal and oil combustion included mostly ions and trace elements with a rather low fraction of absorbing material. The single scattering albedo and aerosol forcing efficiency showed that primary particles emitted from wood combustion and some cases of oil combustion would have a clear climate warming effect even over dark earth surfaces. Instead, coal combustion particle emissions had a cooling effect. Secondary processes in the atmosphere will further change the radiative properties of these emissions but are not considered in this study. PMID:24328080

  14. Conversion of a black liquor recovery boiler to wood firing: A case history

    SciTech Connect

    Eleniewski, M.A.

    1994-12-31

    In 1983 a large integrated pulp and paper mill in southeastern United States retired an older chemical recovery boiler when it was replaced by a newer and larger unit as part of a mill expansion. At that time the mill was generating steam and power using wood waste, natural gas and black liquor, a common fuel mix for pulp mills. The retirement of the recovery boiler presented an opportunity for the mill and corporate engineering to evaluate various mixes of fuels for the mill.

  15. Chemical composition of particles from traditional burning of Pakistani wood species

    NASA Astrophysics Data System (ADS)

    Shahid, Imran; Kistler, Magdalena; Mukhtar, Azam; Ramirez-Santa Cruz, Carlos; Bauer, Heidi; Puxbaum, Hans

    2015-11-01

    Total particulate matter (TPM) emitted during burning of three types of Pakistani wood (eucalyptus camaldulensis, local name Safeeda; acacia nilotica, local name Kikar, Babul; dalbergia sissoo, Shisham, Tali) in a traditional brick stove were collected and analyzed for anhydrosugars, sugar alcohols, trace metals, soluble ions and carbonaceous species. This is a first study reporting anhydrosugars in wood smoke particles emitted during traditional burning of common wood types in Pakistan. Carbonaceous species showed the highest contribution to the particulate matter. Although the total carbon (TC) contribution was similar for all burnings (64.8-70.2%), the EC/OC ratio varied significantly, from 0.2 to 0.3 for Accacia and Dalbergia to 0.7-0.8 for Eucalyptus and Wood-mix. Among inorganic constituents potassium chloride and silicon were found at levels higher than 1%. The levoglucosan concentrations ranged from 3.0 to 6.6% (average 5.6%) with the highest value for Accacia and lowest value for the wood-mix. The high levoglucosan/mannosan ratios of 20-28 were typical for hardwood. The ratio between levoglucosan and galactosan varied stronger and was found to be around 13-20 for Accacia, Eucalyptus and Wood mix, and 43 for Dalbergia. The determined levoglucosan concentrations allowed assessing the conversion factor for calculation of biomass smoke contribution to ambient particulate matter levels in Pakistan.

  16. A Diagnostic Aid To Pulp Production

    NASA Astrophysics Data System (ADS)

    Kowalski, Allan; Lebensold, Julian M.

    1989-03-01

    Pitch deposits in the production of pulp from wood are a very significant problem in the pulp and paper industry. Conservative estimates place the annual cost at around $30 million a year. At the present time problems in this domain are handled by human experts, whose time might otherwise be available for research. Development of an expert system in this area would be expected to have several beneficial effects. Quantitatively, it will decrease down time, thus allowing for greater production, and qualitatively it will decrease the occurrence of contamination in the final pulp.

  17. Physical and chemical changes during composting of wood chip-bedded and straw-bedded beef cattle feedlot manure.

    PubMed

    Larney, Francis J; Olson, Andrew F; Miller, Jim J; DeMaere, Paul R; Zvomuya, Francis; McAllister, Tim A

    2008-01-01

    In the 1990s, restrictions on incineration encouraged the forest industry in western Canada to develop new uses for their wood residuals by product. One such use was as a replacement for cereal straw bedding in southern Alberta's beef cattle (Bos taurus) feedlot industry. However, use of carbon (C)-rich bedding, such as wood chips, had implications for subsequent composting of the feedlot manure, a practice that was being increasingly adopted. In a 3-yr study, we compared composting of wood chip-bedded manure (WBM) and barley (Hordeum vulgare L.) straw-bedded manure (SBM). There were no significant differences in temperature regimes of SBM and WBM, indicating similar rates of successful composting. Of 17 physical and chemical parameters, five showed significant (P < 0.10) differences due to bedding at the outset of composting (Day 0), and 11 showed significant differences at final sampling (Day 124). During composting (10 sampling times), seven parameters showed significant bedding effects, 16 showed significant time effects, and four showed a Bedding x Time interaction. Significantly lower (P < 0.10) losses of nitrogen (N) occurred with WBM (19%) compared with SBM (34%), which has positive implications for air quality and use as a soil amendment. Other advantages of WBM compost included significantly higher total C (333 vs. 210 kg Mg(-1) for SBM) and inorganic N (1.3 vs. 1.0 kg Mg(-1) for SBM) and significantly lower total phosphorus (4.5 vs. 5.3 kg Mg(-1) for SBM). Our results showed that wood chip bedding should not be a problem for subsequent composting of the manure after pen cleaning. In combination with other benefits, our findings should encourage the adoption of wood chips over straw as a bedding choice for southern Alberta feedlots. PMID:18396561

  18. Chemical and microbiological changes during vermicomposting of coffee pulp using exotic (Eudrilus eugeniae) and native earthworm (Perionyx ceylanesis) species.

    PubMed

    Raphael, Kurian; Velmourougane, K

    2011-06-01

    Coffee pulp is the main solid residue from the wet processing of coffee berries. Due to presence of anti-physiological and anti-nutritional factors, coffee pulp is not considered as adequate substrate for bioconversion process by coffee farmers. Recent stringent measures by Pollution Control authorities, made it mandatory to treat all the solid and liquid waste emanating from the coffee farms. A study was conducted to evaluate the efficiency of an exotic (Eudrilus eugeniae) and a native earthworm (Perionyx ceylanesis) from coffee farm for decomposition of coffee pulp into valuable vermicompost. Exotic earthworms were found to degrade the coffee pulp faster (112 days) as compared to the native worms (165 days) and the vermicomposting efficiency (77.9%) and vermicompost yield (389 kg) were found to significantly higher with native worms. The multiplication rate of earthworms (280%) and worm yield (3.78 kg) recorded significantly higher with the exotic earthworms. The percentage of nitrogen, phosphorous, potassium, calcium and magnesium in vermicompost was found to increase while C:N ratio, pH and total organic carbon declined as a function of the vermicomposting. The plant nutrients, nitrogen (80.6%), phosphorus (292%) and potassium (550%) content found to increase significantly in the vermicompost produced using native earthworms as compared to the initial values, while the calcium (85.7%) and magnesium (210%) content found to increase significantly in compost produced utilizing exotic worms. Vermicompost and vermicasts from native earthworms recorded significantly higher functional microbial group's population as compared to the exotic worms. The study reveals that coffee pulp can be very well used as substrate for vermicomposting using exotic (Eudrilus eugeniae) and native earthworm (Perionyx ceylanesis). PMID:20922463

  19. Agricultural fibres for pulp and paper manufacture in developed countries

    SciTech Connect

    Wong, A.

    1995-11-01

    Agricultural fibres are routinely used for the manufacture of paper products in developing countries. The agriculture (non-wood) pulp industry accounts more than 50% of the national pulp production in China and in India. In contrast, paper manufacturers of the developed countries have relied largely on wood pulp fibres since the 1950`s. During the past 3 decades, the global wood pulp production capacities has expanded substantially. There is a renewed interest to use agriculture-based fibres in place of wood, for the production of pulp and paper in developing countries. The alternative is driven, in part, by the growing shortage of commercial wood supply as caused by the over-cutting of the standing forest and the accelerated re-allocation of forest land for ecological and recreational uses. Although the shortage of wood supply can be alleviated partially by the adoption of higher-yield wood pulping technologies and by the increased use of waste paper. But ultimately, these remedial steps will be inadequate to meet the growing demand for paper products. There are several important factors which affect the use of agricultural fibres for pulp and paper manufacture in developed countries. For some on-purpose fibre crops, continued farm subsidy and repeal of certain sections of the Narcotics Act would be required. Agri-pulp production from agricultural cropping residues appears to be the most practical economic means to supplement the fibre needs of the paper industry. In the social context, agri-pulp implementation in North America would also provide lower taxes that would be accrued from the elimination of substantial annual subsidies to grain farmers from the government.

  20. Chemical composition and fuel wood characteristics of fast growing tree species in India

    NASA Astrophysics Data System (ADS)

    Chauhan, S. K.; Soni, R.

    2012-04-01

    India is one of the growing economy in the world and energy is a critical input to sustain the growth of development. Country aims at security and efficiency of energy. Though fossil fuel will continue to play a dominant role in energy scenario but country is committed to global environmental well being thus stressing on environment friendly technologies. Concerns of energy security in this changing climatic situation have led to increasing support for the development of new renewable source of energy. Government though is determined to facilitate bio-energy and many projects have been established but initial after-affects more specifically on the domestic fuelwood are evident. Even the biomass power generating units are facing biomass crisis and accordingly the prices are going up. The CDM projects are supporting the viability of these units resultantly the Indian basket has a large number of biomass projects (144 out of total 506 with 28 per cent CERs). The use for fuelwood as a primary source of energy for domestic purpose by the poor people (approx. 80 per cent) and establishment of bio-energy plants may lead to deforestation to a great extent and only solution to this dilemma is to shift the wood harvest from the natural forests to energy plantations. However, there is conspicuous lack of knowledge with regards to the fuelwood characteristics of fast growing tree species for their selection for energy plantations. The calorific value of the species is important criteria for selection for fuel but it is affected by the proportions of biochemical constituents present in them. The aim of the present work was to study the biomass production, calorific value and chemical composition of different short rotation tree species. The study was done from the perspective of using the fast growing tree species for energy production at short rotation and the study concluded that short rotation tree species like Gmelina arborea, Eucalyptus tereticornis, Pongamia pinnata

  1. Alkaline pulping of some eucalypts from Sudan.

    PubMed

    Khristova, P; Kordsachia, O; Patt, R; Dafaalla, S

    2006-03-01

    Four eucalypts (Eucalyptus camaldulensis, Eucalyptus microtheca, Eucalyptus tereticornis and Eucalyptus citriodora) grown in Sudan were examined for their suitability for pulping and papermaking with different alkaline methods. Their physical, morphological and chemical characteristics are reported. The pulping trials with E. citriodora and E. tereticornis were carried out using the kraft-AQ, soda-AQ, modified AS/AQ (ASA), ASAM and kraft methods. For the other two species, only the ASAM and the kraft process were applied. ASAM pulping gave the best results in terms of yield, degree of delignification, mechanical and optical pulp properties. The best pulps, obtained in kraft and ASAM cooking of E. citriodora, were bleached to 88% ISO brightness in a totally chlorine free bleaching sequence (OQ1O/PQ2P). The bleached pulps, especially the ASAM pulp, showed good papermaking properties and would be suitable for manufacture of writing and printing grades of paper. PMID:15935655

  2. Evaluation of Mechanical Properties of Plywood Treated with a new Wood Preservative (CEB) Chemical

    NASA Astrophysics Data System (ADS)

    Kalawate, Aparna; Shahoo, Shadhu Charan; Khatua, Pijus Kanti; Das, Himadri Sekhar

    2016-03-01

    The objective of this study was to explore the physical and mechanical properties of the plywood made with phenolic glue and rubber wood as core veneer with CEB as a wood preservative. The studied properties were glue shear strength in dry, wet mycological, modulus of elasticity, modulus of rupture and tensile strength in parallel to grain direction as per IS:1734 part-4, 11 and 9 (1983) respectively. Results of the above mentioned tests were compared with the prescribed values given in IS 710-2010 and results revealed that samples conformed the prescribed values.

  3. Changes in mechanical and chemical wood properties by electron beam irradiation

    NASA Astrophysics Data System (ADS)

    Schnabel, Thomas; Huber, Hermann; Grünewald, Tilman A.; Petutschnigg, Alexander

    2015-03-01

    This study deals with the influence of various electron beam irradiation (EBI) dosages on the Brinell hardness of Norway spruce. The results of the hardness measurements and the FT-IR spectroscopic analysis show different effects of the EBI at dosages of 25, 50, 100 and 200 kGy. It was assumed that the lignin and carbohydrates undergo different altering mechanisms due to the EBI treatment. New cleavage products and condensation reactions of lignin and carbohydrates lead to better surface hardness of low irradiated wood samples. These results provide a useful basis for further investigations on the changes in wood chemistry and material properties due to electron beam irradiations.

  4. Pollution prevention for the kraft pulp and paper industry

    SciTech Connect

    Not Available

    1992-09-01

    The document is an annotated bibliography of publications related to pollution prevention in the Kraft segment of the pulp and paper industry. It is organized by process area as follows: chip preparation, chemical pulping, pulp washing, bleaching, chemical recovery, recausticizing, power generation, wastewater treatment, papermaking, and general plant. The document contains 269 citations.

  5. Effect of sucrose and pectin addition on physical, chemical, thermal and rheological properties of frozen/thawed pineapple pulps

    NASA Astrophysics Data System (ADS)

    Conceição, Márcia Cavalcante; Fernandes, Tatiana Nunes; Prado, Mônica Elisabeth Torres; de Resende, Jaime Vilela

    2012-09-01

    Pectin (0-1.0 g/100 mL) and sucrose (0-20 g/100 mL) were added to pineapple pulp to improve their rheological properties, thermal properties and stability after freezing and thawing processes. The properties of the mixes were characterized before and after freezing and thawing. Samples were frozen at -20°C, and the freeze concentration was evaluated every 60 min. The thawing rate was evaluated at 19°C and quantified by photographic editing and image analysis software. The thawing rates and values for the freeze concentration were leveled out at pectin concentrations above 0.5 g/100 mL pectin, which indicated that pectin functions to maintain structural homogeneity during freezing. In the thawed samples, the plastic viscosity values were leveled out from pectin concentrations (0.25-0.75 g/100 mL) as the sucrose concentration increased when compared to unfrozen samples. The differences between the rheological parameters of the unfrozen and frozen/thawed pulps, the higher yield stress values after thawing were attributed to the size of suspended particles in the pulp. Applications can specify formulations of frozen products containing pectin, where these properties can be handled after thawing the product.

  6. Chemical characterisation of PM10 emissions from combustion in a closed stove of common woods grown in Portugal

    NASA Astrophysics Data System (ADS)

    Gonçalves, C.; Alves, C.; Pio, C.; Rzaca, M.; Schmidl, C.; Puxbaum, H.

    2009-04-01

    A series of source tests were conducted to determine the wood elemental composition, combustion gases and the chemical constitution of PM10 emissions from the closed stove combustion of four species of woods grown in Portugal: Eucalyptus globulos, Pinus pinaster, Quercus suber and Acacia longifolia. The burning tests were made in a closed stove with a dilution source sampler. To ascertain the combustion phase and conditions, continuous emission monitors measured O2, CO2, CO, NO, hydrocarbons, temperature and pressure, during each burning cycle. Woodsmoke samples have been collected and analysed to estimate the contribution of plant debris and biomass smoke to atmospheric aerosols. At this stage of work, cellulose, anhydrosugars and humic-like substances (HULIS) have been measured. Cellulose was determined photometrically after its conversion to D-Glucose. The determination of levoglucosan and other anhydrosugars, including mannosan and galactosan, was carried out by high performance liquid chromatography with electrochemical detection. HULIS determination was made with a total organic carbon analyser and an infrared non dispersive detector, after the isolation of substances. Cellulose was present in PM10 at mass fractions (w/w) of 0.13%, 0.13%, 0.05% and 0.08% for Eucalyptus globulos, Pinus pinaster, Quercus suber and Acacia longifolia, respectively. Levoglucosan was the major anhydrosugar present in the samples, representing mass fractions of 14.71%, 3.80%, 6.78% and 1.91%, concerning the above mentioned wood species, respectively. The levoglucosan-to-mannosan ratio, usually used to evaluate the proportion of hardwood or softwood smoke in PM10, gave average values of 34.9 (Eucalyptus globulos), 3.40 (Pinus pinaster), 24.8 (Quercus suber) and 10.4 (Acacia longifolia). HULIS were present at mass fractions of 2.35%, 2.99%, 1.52% and 1.72% for the four wood species listed in the same order as before.

  7. Treatment of Copper Contaminated Municipal Wastewater by Using UASB Reactor and Sand-Chemically Carbonized Rubber Wood Sawdust Column.

    PubMed

    Biswas, Swarup; Mishra, Umesh

    2016-01-01

    The performance of a laboratory scale upflow anaerobic sludge blanket (UASB) reactor and its posttreatment unit of sand-chemically carbonized rubber wood sawdust (CCRWSD) column system for the treatment of a metal contaminated municipal wastewater was investigated. Copper ion contaminated municipal wastewater was introduced to a laboratory scale UASB reactor and the effluent from UASB reactor was then followed by treatment with sand-CCRWSD column system. The laboratory scale UASB reactor and column system were observed for a period of 121 days. After the posttreatment column the average removal of monitoring parameters such as copper ion concentration (91.37%), biochemical oxygen demand (BODT) (93.98%), chemical oxygen demand (COD) (95.59%), total suspended solid (TSS) (95.98%), ammonia (80.68%), nitrite (79.71%), nitrate (71.16%), phosphorous (44.77%), total coliform (TC) (99.9%), and fecal coliform (FC) (99.9%) was measured. The characterization of the chemically carbonized rubber wood sawdust was done by scanning electron microscope (SEM), X-ray fluorescence spectrum (XRF), and Fourier transforms infrared spectroscopy (FTIR). Overall the system was found to be an efficient and economical process for the treatment of copper contaminated municipal wastewater. PMID:26904681

  8. Treatment of Copper Contaminated Municipal Wastewater by Using UASB Reactor and Sand-Chemically Carbonized Rubber Wood Sawdust Column

    PubMed Central

    Biswas, Swarup; Mishra, Umesh

    2016-01-01

    The performance of a laboratory scale upflow anaerobic sludge blanket (UASB) reactor and its posttreatment unit of sand-chemically carbonized rubber wood sawdust (CCRWSD) column system for the treatment of a metal contaminated municipal wastewater was investigated. Copper ion contaminated municipal wastewater was introduced to a laboratory scale UASB reactor and the effluent from UASB reactor was then followed by treatment with sand-CCRWSD column system. The laboratory scale UASB reactor and column system were observed for a period of 121 days. After the posttreatment column the average removal of monitoring parameters such as copper ion concentration (91.37%), biochemical oxygen demand (BODT) (93.98%), chemical oxygen demand (COD) (95.59%), total suspended solid (TSS) (95.98%), ammonia (80.68%), nitrite (79.71%), nitrate (71.16%), phosphorous (44.77%), total coliform (TC) (99.9%), and fecal coliform (FC) (99.9%) was measured. The characterization of the chemically carbonized rubber wood sawdust was done by scanning electron microscope (SEM), X-ray fluorescence spectrum (XRF), and Fourier transforms infrared spectroscopy (FTIR). Overall the system was found to be an efficient and economical process for the treatment of copper contaminated municipal wastewater. PMID:26904681

  9. HIGHLY ENERGY EFFICIENT D-GLU (DIRECTED-GREEN LIQ-UOR UTILIZATION) PULPING

    SciTech Connect

    Lucia, Lucian A

    2013-04-19

    Purpose: The purpose of the project was to retrofit the front end (pulp house) of a commercial kraft pulping mill to accommodate a mill green liquor (GL) impregna-tion/soak/exposure and accrue downstream physical and chemical benefits while prin-cipally reducing the energy footprint of the mill. A major player in the mill contrib-uting to excessive energy costs is the lime kiln. The project was intended to offload the energy (oil or natural gas) demands of the kiln by by-passing the causticization/slaking site in the recovery area and directly using green liquor as a pulping medium for wood. Scope: The project was run in two distinct, yet mutually compatible, phases: Phase 1 was the pre-commercial or laboratory phase in which NC State University and the Insti-tute of Paper Science and Technology (at the Georgia Institute of Technology) ran the pulping and associated experiments, while Phase 2 was the mill scale trial. The first tri-al was run at the now defunct Evergreen Pulp Mill in Samoa, CA and lead to a partial retrofit of the mill that was not completed because it went bankrupt and the work was no longer the low-hanging fruit on the tree for the new management. The second trial was run at the MeadWestvaco Pulp Mill in Evedale, TX which for all intents and pur-poses was a success. They were able to fully retrofit the mill, ran the trial, studied the pulp properties, and gave us conclusions.

  10. Recalcitrant organic compounds (chemical oxygen demand sources) in biologically treated pulp and paper mill effluents: Their fate and environmental impact in receiving waters

    SciTech Connect

    Archibald, F.; Roy-Arcand, L.; Methot, M.; Valeanu, L.

    1998-11-01

    Most North American pulp and paper mills now biologically treat (biotreat) their liquid effluent. However, treated water still contains effluent-derived recalcitrant organic material (EROM), measured as chemical oxygen demand (COD), for which emission limits exist in Europe and are being considered in the US. Production of microbially resistant, dissolved natural organic material (NOM) typically found in Canadian stream and lake waters occurs slowly under gentle conditions, while mill EROM is generated from lignocellulosics by faster and harsher processes. Similarity of the environmental effects of NOM and pulp and paper mill EROM are examined. Changes occurring over 4 months in biologically treated effluent from two modern Canadian mills and lake NOM when sealed in gas- and light-permeable bags and placed in a pristine Quebec lake are reported. Addition of microbial co-metabolites significantly improved the dark mineralization of organochlorines surviving mill biological treatment. Mill EROM was light sensitive, nonacutely toxic in the Microtox assay, and similar to NOM in the surrounding lake in most bulk properties. There was no evidence to suggest that placing specific limits on mill EROM (COD) emissions would be environmentally beneficial.

  11. Chemical constituent influence on ionizing radiation treatment of a wood-plastic composite

    NASA Astrophysics Data System (ADS)

    Palm, Andrew; Smith, Jennifer; Driscoll, Mark; Smith, Leonard; Scott Larsen, L.

    2016-07-01

    A dose range of 0-200 kGy was used to irradiate polyethylene-based wood plastic composite (WPC) specimens. An evaluation of mechanical properties in bending resulted in an increase in ultimate strength, but little effect to stiffness. The bending test results were compared to previous testing in order to examine reproducibility. Hardness tests were also conducted, revealing an increase at a dose range of 0-250 kGy.

  12. Exposure of wood in floodplains affects its chemical quality and its subsequent breakdown in streams.

    PubMed

    del Campo, Rubén; Gómez, Rosa

    2016-02-01

    In stream ecosystems, coarse organic matter from the riparian vegetation, a key food resource, is often retained in the floodplains before reaching the channel. During floodplain exposure, organic matter can be affected by abiotic and biotic processes ("preconditioning"), which alter its quality and affect its subsequent decomposition in streams. We analyzed the effect of floodplain preconditioning on wood quality (lignin, C, N, P, K, among others), and its subsequent aquatic breakdown, paying special attention to microbial activity. We simulated preconditioned standard wooden sticks on one arid stream floodplain for 3 and 4 months, and then monitored their breakdown in three different streams, together with control (non-preconditioned) sticks. Preconditioning reduced lignin mass and C:N and lignin:N ratios, caused the leaching of soluble nutrients such as P and K, as well as N immobilization by microbes. These changes enhanced the breakdown of wood in the first week of immersion, but had no effect on breakdown rates after 4 months of incubation in the streams, although N immobilization was diminished. Our results suggest that terrestrial preconditioning could alter the role of wood as a long-lasting nutrients and energy source for freshwater ecosystem. PMID:26613519

  13. Determination of molecular weight distributions in native and pretreated wood.

    PubMed

    Leskinen, Timo; Kelley, Stephen S; Argyropoulos, Dimitris S

    2015-03-30

    The analysis of native wood components by size-exclusion chromatography (SEC) is challenging. Isolation, derivatization and solubilization of wood polymers is required prior to the analysis. The present approach allowed the determination of molecular weight distributions of the carbohydrates and of lignin in native and processed woods, without preparative component isolation steps. For the first time a component selective SEC analysis of sawdust preparations was made possible by the combination of two selective derivatization methods, namely; ionic liquid assisted benzoylation of the carbohydrate fraction and acetobromination of the lignin in acetic acid media. These were optimized for wood samples. The developed method was thus used to examine changes in softwood samples after degradative mechanical and/or chemical treatments, such as ball milling, steam explosion, green liquor pulping, and chemical oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The methodology can also be applied to examine changes in molecular weight and lignin-carbohydrate linkages that occur during wood-based biorefinery operations, such as pretreatments, and enzymatic saccharification. PMID:25563943

  14. Methods for Facilitating Microbial Growth on Pulp Mill Waste Streams and Characterization of the Biodegradation Potential of Cultured Microbes

    PubMed Central

    Mathews, Stephanie L.; Ayoub, Ali S.; Pawlak, Joel; Grunden, Amy M.

    2013-01-01

    The kraft process is applied to wood chips for separation of lignin from the polysaccharides within lignocellulose for pulp that will produce a high quality paper. Black liquor is a pulping waste generated by the kraft process that has potential for downstream bioconversion. However, the recalcitrant nature of the lignocellulose resources, its chemical derivatives that constitute the majority of available organic carbon within black liquor, and its basic pH present challenges to microbial biodegradation of this waste material. Methods for the collection and modification of black liquor for microbial growth are aimed at utilization of this pulp waste to convert the lignin, organic acids, and polysaccharide degradation byproducts into valuable chemicals. The lignocellulose extraction techniques presented provide a reproducible method for preparation of lignocellulose growth substrates for understanding metabolic capacities of cultured microorganisms. Use of gas chromatography-mass spectrometry enables the identification and quantification of the fermentation products resulting from the growth of microorganisms on pulping waste. These methods when used together can facilitate the determination of the metabolic activity of microorganisms with potential to produce fermentation products that would provide greater value to the pulping system and reduce effluent waste, thereby increasing potential paper milling profits and offering additional uses for black liquor. PMID:24378616

  15. Methods for facilitating microbial growth on pulp mill waste streams and characterization of the biodegradation potential of cultured microbes.

    PubMed

    Mathews, Stephanie L; Ayoub, Ali S; Pawlak, Joel; Grunden, Amy M

    2013-01-01

    The kraft process is applied to wood chips for separation of lignin from the polysaccharides within lignocellulose for pulp that will produce a high quality paper. Black liquor is a pulping waste generated by the kraft process that has potential for downstream bioconversion. However, the recalcitrant nature of the lignocellulose resources, its chemical derivatives that constitute the majority of available organic carbon within black liquor, and its basic pH present challenges to microbial biodegradation of this waste material. Methods for the collection and modification of black liquor for microbial growth are aimed at utilization of this pulp waste to convert the lignin, organic acids, and polysaccharide degradation byproducts into valuable chemicals. The lignocellulose extraction techniques presented provide a reproducible method for preparation of lignocellulose growth substrates for understanding metabolic capacities of cultured microorganisms. Use of gas chromatography-mass spectrometry enables the identification and quantification of the fermentation products resulting from the growth of microorganisms on pulping waste. These methods when used together can facilitate the determination of the metabolic activity of microorganisms with potential to produce fermentation products that would provide greater value to the pulping system and reduce effluent waste, thereby increasing potential paper milling profits and offering additional uses for black liquor. PMID:24378616

  16. Composts with and without wood ash admixture for the management of tropical acid soils: chemical, physical and microbiological effects

    NASA Astrophysics Data System (ADS)

    Bougnom, B. P.; Insam, H.; Etoa, F. X.

    2009-04-01

    Acid soils generally found in the tropics have a low pH, are poor in organic matter, deficient in Ca2+, Mg+, P, or Mo ; limited in mineralization, nitrification, nodulation, and mycorrhizal infection , suffer from Al or Mn toxicity. Within the framework aiming at using organic wastes and wood ash to overcome soil infertility in tropical acidic soils, a green house experiment was conducted with two acid soils collected from Cameroon (Ferralsol and Acrisol) and amended with three types of compost 3:1(W/W) containing 0 (K0), 8(K8) and 16% (K16) wood ash admixture respectively for two consecutive cycles of 100 days, during which soybean (Glycine max) was grown on the first, the second cycle was left as fallow. Generally the same trends of variation of the physico-chemical parameters were observed in both soils. Addition of organic wastes increased the pH electrical conductivity, soil organic matter, water holding capacity, total Carbone and total nitrogen as compared to the controls. The rate of nitrification highly increased posing the problem of possible leaching of nitrates in the ground water. The cations and micronutrients content followed the same trends. These changes leaded to an increase of the P availability and a decrease of Al toxicity. At the end of the second cycle, generally most of the different parameters slightly decreased except for the electrical conductivity. All composts passed a toxicity test, and the amended soils had significant better fresh and dried plant biomass, the Total nitrogen also significantly increased. Amended soils with K0 generally performed better than those amended with K8 and K16, thinking that their pH (closer to the neutrality) was responsible of these performances, all the parameters were significantly correlated to the pH. K8 and K16 performances could be performed by reducing the added quantities. The study of PCR-DGGE have shown a shift in the fungal and bacterial communities, Ammonia oxidizing bacteria community were

  17. Strength loss in kraft pulping

    NASA Astrophysics Data System (ADS)

    Iribarne, Jose

    Unbleached kraft pulps from two U.S. mills were 21% and 26% weaker than comparable laboratory pulps from the same chip sources, when assessed as the tear index at a tensile index of 70 kN.m/kg. The phenomena involved were clarified by characterizing the differences between the mill and laboratory pulps in terms of fundamental fiber properties. All of the strength loss could be explained by a reduction in intrinsic fiber strength of 9% to 11%, as estimated from wet zero-span tensile tests and fiber length distributions. Most of the effects of different fiber shape and length were isolated by PFI mill refining and decrilling, respectively. The higher fiber coarseness of mill pulps was a factor in their maximum density and bond strength, but changes in these variables were analogous to those of laboratory pups due to similar swelling. Specific bond strength, determined from a wet pressing experiment, was similar in mill and laboratory pulps. Neither carbohydrate composition nor crystalline structure, assessed through x-ray diffraction analysis, were significant factors in the observed fiber strength differences. The mill pulps were not more heterogeneous than the laboratory pulps, within the resolution of a fractionation experiment. The number of weak points in each pulp was assessed through analysis of the amount of fiber cutting during PFI mill refining and treatments with potassium superoxide or cellulase. The results suggested that the chemistry of kraft pulping preferentially weaken short, slender fibers, while mechanical stresses during the hot discharge of batch digesters mainly affect long, thick fibers. The greater number of weak points in the long-fiber fractions of mill pulps is probably associated with their lower wet zero-span tensile indices. Automated optical detection of major singularities with a prototype instrument suggested that only the weak points induced by mechanical stress could be detected by local variations in birefringence. In contrast

  18. Biological pretreatment for thermomechanical (TMP) and chemithermomechanical (CTMP) pulping processes

    SciTech Connect

    Myers, G.C.; Akhtar, M.; Lentz, M.

    1996-10-01

    Treatment of wood chips with lignin-degrading fungi prior to preparing a refiner mechanical pulp (RMP) has substantially reduced energy consumption and increased paper strength properties. This study reports on thermomechanical (TMP) and chemithermo-mechanical pulping (CTMP) of fungus treated wood chips. Loblolly pine chips were innoculated with Ceriporiopsis subvermispora, strain L14807 SS-3, and incubated two weeks in a chip silo. A pressurized 305 mm diameter disk refiner was used to prepare TMP and CTMP`s from fungal treated and non-treated wood chips. Two procedures were used to prepare the CTMP`s, injecting a sodium hydroxide and hydrogen peroxide solution into the pressurized refiner, and impregnating the wood chips with a sodium sulfite solution. Energy consumption during pulp preparation and handsheet strength and optical properties will be presented and discussed.

  19. Biomechanical pulping: A mill-scale evaluation

    SciTech Connect

    Akhtar, M.; Scott, G.M.; Swaney, R.E.; Shipley, D.F.

    1999-07-01

    Mechanical pulping process is electrical energy intensive and results in low paper strength. Biomechanical pulping, defined as the fungal treatment of lignocellulosic materials prior to mechanical pulping, has shown at least 30% savings in electrical energy consumption, and significant improvements in paper strength properties compared to the control at a laboratory scale. In an effort to scale-up biomechanical pulping to an industrial level, fifty tons of spruce wood chips were inoculated with the best biopulping fungus in a continuous operation and stored in the form of an outdoor chip pile for two weeks. The pile was ventilated with conditioned air to maintain the optimum growth temperature and moisture throughout the pile. The control and fungus-treated chips were refined through a thermomechanical pulp mill (TMP) producing lightweight coated paper. The fungal pretreatment saved 33% electrical energy and improved paper strength properties significantly compared to the control. Since biofibers were stronger than the conventional TMP fibers, the authors were able to reduce the amount of bleached softwood kraft pulp by at least 5% in the final product. Fungal pretreatment reduced brightness, but brightness was restored to the level of bleached control with 60% more hydrogen peroxide. The economics of biomechanical pulping look attractive.

  20. The Influence of Process Conditions on the Chemical Composition of Pine Wood Catalytic Pyrolysis Oils

    DOE PAGESBeta

    Pereira, J.; Agblevor, F. A.; Beis, S. H.

    2012-01-01

    Pine wood samples were used as model feedstock to study the properties of catalytic fast pyrolysis oils. The influence of two commercial zeolite catalysts (BASF and SudChem) and pretreatment of the pine wood with sodium hydroxide on pyrolysis products were investigated. The pyrolysis oils were first fractionated using column chromatography and characterized using GC-MS. Long chain aliphatic hydrocarbons, levoglucosan, aldehydes and ketones, guaiacols/syringols, and benzenediols were the major compounds identified in the pyrolysis oils. The catalytic pyrolysis increased the polycyclic hydrocarbons fraction. Significant decreases in phthalate derivatives using SudChem and long chain aliphatics using BASF catalyst were observed. Significant amountsmore » of aromatic heterocyclic hydrocarbons and benzene derivatives were formed, respectively, using BASF and SudChem catalysts. Guaiacyl/syringyl and benzenediols derivatives were partly suppressed by the zeolite catalysts, while the sodium hydroxide treatment enriched phenolic derivatives. Zeolite catalyst and sodium hydroxide were employed together; they showed different results for each catalyst.« less

  1. Determination of hot and cool burning residential wood combustion source strengths using chemical mass balance modeling

    SciTech Connect

    Rau, J.A.; Huntzicker, J.J.; Khalil, M.A.K. )

    1987-01-01

    This paper compares CMB results using separate hot and cool RWC source composition profiles, a composite of hot and cool composition profiles weighted according reported stove usage patterns, and the conventional EPA RWC source composition profile. These profiles are shown. Since the composition of hot and cool burn particles is dramatically different, hot and cool burn composition profiles can be used as separate sources in the same CMB model. Hot burning RWC particles are black, have a mild acrid smell and contain from 20 to 60% carbon (up to 80% of the carbon can be in the form of elemental carbon) and high levels of trace elements (5-25%K, 2-5% S and 2-4% Cl). In contrast, cool or smoldering burn smoke particles are tan, have a strong pleasant wood smoke smell, and contain 55-60% carbon which is mostly in the form of organic carbon with only a few percent of elemental carbon. The concentrations of trace elements in cool burning emissions are generally less than 0.1%. During hot burning the RWC smoke plume is practically invisible, while during cool burning the plume is very visible and has the typical blue-gray color associated with wood burning. For similar amounts of fuel burning in a stove, emission levels for cool burning are an average of 4.8 times higher than for hot burning.

  2. Development of hemicelluloses biorefineries for integration into kraft pulp mills

    NASA Astrophysics Data System (ADS)

    Ajao, Olumoye Abiodun

    The development and wide spread acceptance of production facilities for biofuels, biochemicals and biomaterials is an important condition for reducing reliance on limited fossil resources and transitioning towards a global biobased economy. Pulp and paper mills in North America are confronted with high energy prices, high production costs and intense competition from emerging economies and low demand for traditional products. Integrated forest biorefineries (IFBR) have been proposed as a mean to diversify their product streams, increase their revenue and become more sustainable. This is feasible because they have access to forest biomass, an established feedstock supply chain and wood processing experience. In addition, the integration of a biorefinery process that can share existing infrastructure and utilities on the site of pulp mill would significantly lower investment cost and associated risks. Kraft pulping mills are promising receptor processes for a biorefinery because they either possess a prehydrolysis step for extracting hemicelluloses sugars prior to wood pulping or it can be added by retrofit. The extracted hemicelluloses could be subsequently transformed into a wide range of value added products for the receptor mill. To successfully implement hemicelluloses biorefinery, novel processes that are technically and economically feasible are required. It is necessary to identify products that would be profitable, develop processes that are energy efficient and the receptor mill should be able to supply the energy, chemicals and material demands of the biorefinery unit. The objective of this thesis is to develop energy efficient and economically viable hemicelluloses biorefineries for integration into a Kraft pulping process. A dissolving pulp mill was the reference case study. The transformation of hemicellulosic sugars via a chemical and biochemical conversion pathway, with furfural and ethanol as representative products for each pathway was studied. In

  3. Genetic and environmental modification of the mechanical properties of wood

    NASA Astrophysics Data System (ADS)

    Sederoff, R.; Allona, I.; Whetten, R.

    1996-02-01

    Wood is one of the nation's leading raw materials and is used for a wide variety of products, either directly as wood, or as derived materials in pulp and paper. Wood is a biological material and evolved to provide mechanical support and water transport to the early plants that conquered the land. Wood is a tissue that results from the differentiation and programmed cell death of cells that derive from a tissue known as the vascular cambium. The vascular cambium is a thin cylinder of undifferentiated tissue in plant stems and roots that gives rise to several different cell types. Cells that differentiate on the internal side of the cambium form xylem, a tissue composed in major part, of long thin cells that die leaving a network of interconnected cell walls that serve to transport water and to provide mechanical support for the woody plant. The shape and chemical composition of the cells in xylem are well suited for these functions. The structure of cells in xylem determines the mechanical properties of the wood because of the strength derived from the reinforced matrix of the wall. The hydrophobic phenolic surface of the inside of the cell walls is essential to maintain surface tension upon which water transport is based and to resist decay caused by microorganisms. The properties of wood derived from the function of xylem also determine its structural and chemical properties as wood and paper products. Therefore, the physical and chemical properties of wood and paper products also depend on the morphology and composition of the cells from which they are derived. Wood (xylem cell walls) is an anisotropic material, a composite of lignocellulose. It is a matrix of cellulose microfibrils, complexed with hemicelluloses, (carbohydrate polymers which contain sugars other than glucose, both pentoses and hexoses), embedded together in a phenolic matrix of lignin. The high tensile strength of wood in the longitudinal direction, is due to the structure of cellulose and the

  4. Simultaneous bench scale production of dissolving grade pulp and valuable hemicelluloses from softwood kraft pulp by ionic liquid extraction.

    PubMed

    Laine, Christiane; Asikainen, Sari; Talja, Riku; Stépán, Agnes; Sixta, Herbert; Harlin, Ali

    2016-01-20

    Ionic liquid extraction of wood pulp has been highlighted as a highly potential new process for dissolving pulp production. Coproduction with a polymeric hemicellulose fraction was demonstrated in bench scale from softwood kraft pulp using extraction with the ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIM OAc) and water. In total, the recovered pulp and hemicellulose fraction together yielded 95.5 wt.% of the pulp input. The extracted pulp had a remarkably high purity with an R18-value of 97.8%. The hemicellulose fraction consisted of galactoglucomannan, arabinoxylan and some cellulose and was precipitated from the ionic liquid-water mixture. After hydroxypropylation of the hemicellulose fraction, films were prepared and barrier and strength properties were compared to films from other polysaccharides. Reduced oxygen and water vapor permeation and good strength properties were demonstrated when compared to corresponding films from hydroxypropylated xylan from cold caustic extraction. The films have potential for applications in food packaging and edible films. PMID:26572370

  5. Supporting rural wood industry through timber utilization research. Research paper

    SciTech Connect

    Skog, K.

    1991-10-01

    The report evaluates the potential impact of USDA Forest Service wood utilization and wood energy research on rural employment and income. Recent projections suggest employment will decrease in many forest products industries, such as softwood sawmilling, but will eventually increase in softwood plywood and reconstituated panel mills. Forest products industries expected to provide wages exceeding the average manufacturing production wage include logging, softwood sawmills, millwork, softwood plywood--veneer, structural wood members, particle-board, wood partitions, pulp mills, paper mills, and paperboard mills. Industries expected to pay 90 percent of the average manufacturing production wage include wood kitchen cabinets, mobile homes, prefabricated wood buildings, and wood preservatives.

  6. Alkaline polyol pulping and enzymatic hydrolysis of hardwood: effect of pulping severity and pulp composition on cellulase activity and overall sugar yield.

    PubMed

    Hundt, Martin; Schnitzlein, Klaus; Schnitzlein, Michael G

    2013-05-01

    The saccharification of beech wood using alkaline polyol pulping (AlkaPolP) and enzymatic hydrolysis was investigated. It will be demonstrated that the AlkaPolP process yields high quality pulps which can easily be hydrolyzed by cellulases. In order to find optimum reaction conditions chips of Fagus sylvatica were pretreated by alkaline glycerol at temperatures between 190 and 230 °C for 15, 20, and 25 min. The impacts of temperature and time were expressed using a severity factor R0. The dependencies of the conversion during enzymatic hydrolysis on severity, pulp yield, delignification and pulp composition are shown. In further experiments it was investigated if the sugar yields can be increased by the application of ultrasound or surfactants before enzyme addition. Up to 95% of the initial cellulose in wood were converted into glucose using cellulases from Trichoderma reesei and β-glucosidase from Aspergillus niger. PMID:23570715

  7. Yield Improvement and Energy Savings Uing Phosphonates as Additives in Kraft pulping

    SciTech Connect

    Ulrike W. Tschirner; Timothy Smith

    2007-03-31

    Project Objective: Develop a commercially viable modification to the Kraft process resulting in energy savings, increased yield and improved bleachability. Evaluate the feasibility of this technology across a spectrum of wood species used in North America. Develop detailed fundamental understanding of the mechanism by which phosphonates improve KAPPA number and yield. Evaluate the North American market potential for the use of phosphonates in the Kraft pulping process. Examine determinants of customer perceived value and explore organizational and operational factors influencing attitudes and behaviors. Provide an economic feasibility assessment for the supply chain, both suppliers (chemical supply companies) and buyers (Kraft mills). Provide background to most effectively transfer this new technology to commercial mills.

  8. Migration of wood-preserving chemicals in contaminated groundwater in a sand aquifer at Pensacola, Florida

    USGS Publications Warehouse

    Goerlitz, D.F.; Troutman, D.E.; Godsy, E.M.; Franks, B.J.

    1985-01-01

    Operation of a wood-preserving facility for nearly 80 years at Pensacola, FL, contaminated the near-surface groundwater with creosote and pentachlorophenol. The major source of aquifer contamination was unlined surface impoundments that were in direct hydraulic contact with the groundwater. Episodes of overtopping the impoundments and overland flow of treatment liquor and waste were also significant to the migration and contamination of the groundwater. Solutes contaminating the ground-water are mainly naphthalene and substituted phenols. Sorption did not influence retardation of solutes in transport in the groundwater. Phenol and the mono substituted methylphenols appear to be undergoing bio-transformation. Pentachlorophenol (PCP) was not found in significant concentrations in the groundwater possibly because the solubility of PCP is approximately 5 mg/L at pH 6, near the average acidity for the groundwater.

  9. 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.

  10. Estimation of wood density and chemical composition by means of diffuse reflectance mid-infrared Fourier transform (DRIFT-MIR) spectroscopy.

    PubMed

    Nuopponen, Mari H; Birch, Gillian M; Sykes, Rob J; Lee, Steve J; Stewart, Derek

    2006-01-11

    Sitka spruce (Picea sitchensis) samples (491) from 50 different clones as well as 24 different tropical hardwoods and 20 Scots pine (Pinus sylvestris) samples were used to construct diffuse reflectance mid-infrared Fourier transform (DRIFT-MIR) based partial least squares (PLS) calibrations on lignin, cellulose, and wood resin contents and densities. Calibrations for density, lignin, and cellulose were established for all wood species combined into one data set as well as for the separate Sitka spruce data set. Relationships between wood resin and MIR data were constructed for the Sitka spruce data set as well as the combined Scots pine and Sitka spruce data sets. Calibrations containing only five wavenumbers instead of spectral ranges 4000-2800 and 1800-700 cm(-1) were also established. In addition, chemical factors contributing to wood density were studied. Chemical composition and density assessed from DRIFT-MIR calibrations had R2 and Q2 values in the ranges of 0.6-0.9 and 0.6-0.8, respectively. The PLS models gave residual mean squares error of prediction (RMSEP) values of 1.6-1.9, 2.8-3.7, and 0.4 for lignin, cellulose, and wood resin contents, respectively. Density test sets had RMSEP values ranging from 50 to 56. Reduced amount of wavenumbers can be utilized to predict the chemical composition and density of a wood, which should allow measurements of these properties using a hand-held device. MIR spectral data indicated that low-density samples had somewhat higher lignin contents than high-density samples. Correspondingly, high-density samples contained slightly more polysaccharides than low-density samples. This observation was consistent with the wet chemical data. PMID:16390174

  11. The potential in bioethanol production from waste fiber sludges in pulp mill-based biorefineries.

    PubMed

    Sjöde, Anders; Alriksson, Björn; Jönsson, Leif J; Nilvebrant, Nils-Olof

    2007-04-01

    Industrial production of bioethanol from fibers that are unusable for pulp production in pulp mills offers an approach to product diversification and more efficient exploitation of the raw material. In an attempt to utilize fibers flowing to the biological waste treatment, selected fiber sludges from three different pulp mills were collected, chemically analyzed, enzymatically hydrolyzed, and fermented for bioethanol production. Another aim was to produce solid residues with higher heat values than those of the original fiber sludges to gain a better fuel for combustion. The glucan content ranged between 32 and 66% of the dry matter. The lignin content varied considerably (1-25%), as did the content of wood extractives (0.2-5.8%). Hydrolysates obtained using enzymatic hydrolysis were found to be readily fermentable using Saccharomyces cerevisiae. Hydrolysis resulted in improved heat values compared with corresponding untreated fiber sludges. Oligomeric xylan fragments in the solid residue obtained after enzymatic hydrolysis were identified using matrix-assisted laser desorption ionization-time of flight and their potential as a new product of a pulp mill-based biorefinery is discussed. PMID:18478399

  12. The Potential in Bioethanol Production From Waste Fiber Sludges in Pulp Mill-Based Biorefineries

    NASA Astrophysics Data System (ADS)

    Sjöde, Anders; Alriksson, Björn; Jönsson, Leif J.; Nilvebrant, Nils-Olof

    Industrial production of bioethanol from fibers that are unusable for pulp production in pulp mills offers an approach to product diversification and more efficient exploitation of the raw material. In an attempt to utilize fibers flowing to the biological waste treatment, selected fiber sludges from three different pulp mills were collected, chemically analyzed, enzymatically hydrolyzed, and fermented for bioethanol production. Another aim was to produce solid residues with higher heat values than those of the original fiber sludges to gain a better fuel for combustion. The glucan content ranged between 32 and 66% of the dry matter. The lignin content varied considerably (1-25%), as did the content of wood extractives (0.2-5.8%). Hydrolysates obtained using enzymatic hydrolysis were found to be readily fermentable using Saccharomyces cerevisiae. Hydrolysis resulted in improved heat values compared with corresponding untreated fiber sludges. Oligomeric xylan fragments in the solid residue obtained after enzymatic hydrolysis were identified using matrix-assisted laser desorption ionization-time of flight and their potential as a new product of a pulp mill-based biorefinery is discussed.

  13. Controlling the release of wood extractives into water bodies by selecting suitable eucalyptus species

    NASA Astrophysics Data System (ADS)

    Kilulya, K. F.; Msagati, T. A. M.; Mamba, B. B.; Ngila, J. C.; Bush, T.

    Pulping industries are increasing worldwide as a result of the increase in the demand for pulp for cellulose derivatives and paper manufacturing. Due to the activities involved in pulping processes, different chemicals from raw materials (wood) and bleaching agents are released in pulp-mill effluent streams discharged into the environment and find their way into water bodies. Large quantities of water and chemicals used in pulping result in large amounts of wastewater with high concentrations of extractives such as unsaturated fatty acids, which are known to be toxic, and plant sterols which affect the development, growth and reproduction of aquatic organisms. This study was aimed at assessing the composition of extractives in two eucalyptus species used for pulp production in South Africa, in order to identify the suitable species with regard to extractive content. Samples from two eucalyptus plant species (Eucalyptus grandis and Eucalyptus dunnii) were collected from three sites and analysed for extractives by first extracting with water, followed by Soxhlet extraction using acetone. Compounds were identified and quantified using gas chromatography-mass spectrometry (GC-MS). Major classes of extractives identified were fatty acids (mainly hexadecanoic acid, 9,12-octadecadienoic, 9-octadecenoic and octadecanoic acids) and sterols (mainly β-sitosterol and stigmastanol). E. dunnii was found to contain higher amounts of the compounds compared to those found in E. grandis in all sampled sites. Principal component analysis (PCA) was performed and explained 92.9% of the total variation using three principal components. It was revealed that the percentage of fatty acids, which has a negative influence on both principal components 2 and 3, was responsible for the difference between the species. E. grandis, which was found to contain low amounts of extractives, was therefore found suitable for pulping with regard to minimal water usage and environment pollution.

  14. Evaluating pulp stiffness from fibre bundles by ultrasound

    NASA Astrophysics Data System (ADS)

    Karppinen, Timo; Montonen, Risto; Määttänen, Marjo; Ekman, Axel; Myllys, Markko; Timonen, Jussi; Hæggström, Edward

    2012-06-01

    A non-destructive ultrasonic tester was developed to measure the stiffness of pulp bundles. The mechanical properties of pulp are important when estimating the behaviour of paper under stress. Currently available pulp tests are tedious and alter the fibres structurally and mechanically. The developed tester employs (933 ± 15) kHz tweezer-like ultrasonic transducers and time-of-flight measurement through (9.0 ± 2.5) mm long and (0.8 ± 0.1) mm thick fibre bundles kept at (19.1 ± 0.4) °C and (62 ± 1)% RH. We determined the stiffness of soft wood pulps produced by three kraft pulping modifications: standard kraft pulp, (5.2 ± 0.4) GPa, prehydrolysis kraft pulp, (4.3 ± 0.4) GPa, and alkali extracted prehydrolysis kraft pulp, (3.3 ± 0.4) GPa. Prehydrolysis and alkali extraction processes mainly lowered the hemicellulose content of the pulps, which essentially decreased the fibre-wall stiffness hence impairing the stiffness of the fibre networks. Our results indicate that the method allows ranking of pulps according to their stiffness determined from bundle-like samples taken at an early phase of the papermaking process.

  15. Wood and Wood Products

    NASA Astrophysics Data System (ADS)

    Young, Raymond A.

    Wood has been utilized by humans since antiquity. Trees provided a source of many products required by early humans such as food, medicine, fuel, and tools. For example, the bark of the willow tree, when chewed, was used as a painkiller in early Greece and was the precursor of the present-day aspirin. Wood served as the primary fuel in the United States until about the turn of the 19th century, and even today over one-half of the wood now harvested in the world is used for heating fuel.

  16. Chemically coupled microwave and ultrasonic pre-hydrolysis of pulp and paper mill waste-activated sludge: effect on sludge solubilisation and anaerobic digestion.

    PubMed

    Tyagi, Vinay Kumar; Lo, Shang-Lien; Rajpal, Ankur

    2014-05-01

    The effects of alkali-enhanced microwave (MW; 50-175 °C) and ultrasonic (US) (0.75 W/mL, 15-60 min) pretreatments, on solubilisation and subsequent anaerobic digestion efficiency of pulp and paper mill waste-activated sludge, were investigated. Improvements in total chemical oxygen demand and volatile suspended solids (VSS) solubilisation were limited to 33 and 39 % in MW pretreatment only (175 °C). It reached 78 and 66 % in combined MW-alkali pretreatment (pH 12 + 175 °C), respectively. Similarly, chemical oxygen demand and VSS solubilisation were 58 and 37 % in US pretreatment alone (60 min) and it improved by 66 and 49 % after US-alkali pretreatment (pH 12 + 60 min), respectively. The biogas yield for US 60 min-alkali (pH 12)-pretreated sludge was significantly improved by 47 and 20 % over the control and US 60 reactors, respectively. The biogas generation for MW (150 °C)-alkali (pH 12)-pretreated sludge was only 6.3 % higher than control; however, it was 8.3 % lower than the MW (150 °C) reactor, which was due to the inhibition of anaerobic activity under harsh thermal-alkali treatment condition. PMID:24488518

  17. Selective fractionation of Sugar Beet Pulp for release of fermentation and chemical feedstocks; optimisation of thermo-chemical pre-treatment.

    PubMed

    Hamley-Bennett, C; Lye, G J; Leak, D J

    2016-06-01

    The effect of time and pressure on the selective extraction of sugar beet pectin using steam pre-treatment on unprocessed Sugar Beet Pulp was evaluated using a design of experiments approach. This process gave the highest solubilisation of pectin oligomers at a relatively low pressure and longer time (5Bar, 24min), whilst leaving the majority of the cellulose fraction intact. This method of steam pre-treatment fits into the concept of a sugar beet biorefinery as it valorises an existing waste stream without requiring any further physical processing such as milling or dilution with water. The residual cellulose fraction was enriched in cellulose and could be effectively fermented into ethanol by yeast after enzymatic digestion, producing 0.48g ethanol per gram of glucose. PMID:26978325

  18. Wood fuel potential from harvested areas in the Eastern United States

    SciTech Connect

    Carpenter, E.M.

    1980-01-01

    In this paper, we assess the amount of residues and unutilized wood material potentially available from logging operations in the eastern United States. Salvage of these residue materials could greatly increase the utilization of available fiber. We focus on the potential wood fuel that may be available from harvested areas within reach of the skidder. Included are estimates from sources usually overlooked in forest inventories - cull sections, bark, tops, and limbs. Also included is material from rough and rotten trees and from trees cut on noncommercial and nonforest land. Although we emphasize the potential use of residue as a fuel, much of the material may also be suitable for pulp, fiber, or chemicals. Eventual use will depend on the comparative cost of wood residue furnishes relative to other raw material sources.

  19. Isolation and identification of ligands for the goldfish testis androgen receptor in chemical recovery condensates from a Canadian bleached kraft pulp and paper mill.

    PubMed

    Scott, Philip D; Milestone, Craig B; Smith, D Scott; MacLatchy, Deborah L; Hewitt, L Mark

    2011-12-01

    This study builds on a series of investigations characterizing substances in kraft mill chemical recovery condensates that depress sex steroids in fish. Here, incubations of goldfish testis androgen receptors (AR) with condensate extracts were used to investigate the potential role of androgens in hormone depressions. Condensates contained variable levels of AR ligands, with the highest amounts in nonpolar extracts of filtered solids prior to solid phase extraction (SPE). High pressure liquid chromatography (HPLC) fractionation recovered the majority of activity in one fraction, with ligands detected in three additional fractions. Gas chromatography mass spectrometry analysis of the most active fraction confirmed the two most abundant components as the diterpenes manool and geranyl linalool. Manool exhibited a relative affinity for the AR that was 300 fold less than testosterone and accounted for 26% of total filtered solids activity. Geranyl linalool exhibited no affinity for the AR. Three additional diterpenoid families were tentatively identified as principal components of the three other androgenic HPLC fractions. Compared to condensates, final effluent had 3000 fold less androgenic activity, with <1% attributable to manool. Putative androgens previously associated with mill effluents (androstenedione and androstadienedione) and progesterone were not detected; however, additional condensate diterpenes suspected as androgens were identified in final effluent. This study is the first to confirm nonsteroidal cyclic diterpenes as androgenic at pulp mills. A major in-mill source of these substances was identified, and the role of androgens in mill effluents affecting fish reproduction was reinforced. PMID:22040000

  20. A case study of waste management at the Northern Finnish pulp and paper mill complex of Stora Enso Veitsiluoto Mills.

    PubMed

    Nurmesniemi, Hannu; Pöykiö, Risto; Keiski, Riitta Liisa

    2007-01-01

    This work presents the current waste management system at the pulp and paper mill complex of Stora Enso Oyj Veitsiluoto Mills at Kemi, Northern Finland. This paper covers examples of case studies carried out at the mill and describes how the wastes and by-products are utilized as a neutralizing agent for acidic wastewaters (i.e., green liquor dregs from the causticizing process), as a hardener in filling mine cavities (i.e., ash from the fluidized bed boiler), as a landscaping agent (i.e., ash as well as the fibre clay from chemical wastewater treatment plant), as a hydraulic barrier material for landfills (i.e., fibre clay), and as a soil enrichment agent (i.e., calcium carbonate from the precipitated calcium carbonate plant). In addition, the wood waste from the wood-handling plant, sawmill, packaging pallet plant and from the groundwood mill, as well as the biosludge from the biological wastewater treatment plant, are all incinerated in the fluidized bed boiler for energy production. Due to effective utilization of the solid wastes generated at the mills, the annual amount of waste to be disposed of in the landfill has decreased between 1994 and 2004 from 42,990 to 6083 tonn (expressed as wet weight). The paper also gives an overview of the relevant European Union legislation on the forest industry and on waste management, as well as of the pulping process and of the generation of major solid wastes in the pulp and paper mills. PMID:16987647

  1. Fermentation inhibitors and their recovery from acid wood hydrolyzates as chemicals of value

    SciTech Connect

    Tran, Hao Cao.

    1986-01-01

    The principal objective of this study was to demonstrate the technical feasibility of fermentation inhibition removal from acid hydrolyzates of lignocellulosic materials and recovery of the by-products of acid hydrolysis as chemicals of value. The acid hydrolyzates of mixed hardwoods were produced from the continuous flow demonstration unit (CFDU) at the University of California Forest Products Laboratory. Two separate liquid product streams were the prehydrolyzate (S1H) and the second stage hydrolyzate (S2H). Candida utilis NRRL Y-900 and Saccharomyces cerevisiae NRRL 2034 were used to monitor the fermentability of these two product streams, respectively. Two pretreatment methods were investigated in detail: flashing and solvent extraction. For the S1H, flashing was adequate to enable cell production with Candida utilis. The S2H rehired solvent extraction to ensure ethanolic fermentation at high concentrations of glucose (12% or higher). A solvent was selected for the extraction process and process flow designs were proposed to recycle the solvent and isolate commercial by-products, including furfural, methanol, acetic acid and, potentially, formic acid, levulinic acid and 5-hydroxymethylfurfural.

  2. Highly Energy Efficient Directed Green Liquor Utilization (D-GLU) Pulping

    SciTech Connect

    2007-07-01

    This factsheet describes a project that seeks to develop feasible chemical modifications during kraft pulping operations to obtain significant energy and product benefits for U.S. kraft pulp and paper mills.

  3. Trace elements in bivalves from the Rio Cruces, Chile, trace watershed evolution after a major earthquake and challenge a postulated chemical spill from a pulp plant

    NASA Astrophysics Data System (ADS)

    Risk, M.; Burchell, M.; Nairn, R.; Tubrett, M.; Forsterra, G.

    2009-05-01

    In May, 1960, the largest recorded earthquake in the history of the planet hit southern Chile, dropping part of the course of the Rio Cruces by 2m and creating an extensive wetland. The Brazilian Waterweed Egeria densa colonised the area, and became a primary food source for large populations of the Black-necked Swan, Cygnus melancoryphus. In 2004, a large pulp mill commenced operations upstream on the river. According to local reports, immediately after the opening of the plant, the weed died and the swans left. There was public outcry, and a search for a cause or a culprit. It was postulated that some sort of chemical spill from the plant caused the weed to die, resulting in departure of the swans. In 2008, we collected specimens of the bivalve Diplodon chilensis from several locations downstream from the Plant and towards the wetland to see if there was evidence of a chemical spill recorded in the shells. We prepared thin-sections of the shells to observe growth line development and patterns. Additionally, shell samples were analysed for stable oxygen isotopes and trace elements, using LA-ICP/MS. Based on annual growth lines, some of the bivalves were long-lived, with an age of more than 50 years. These individuals settled in the river shortly after the earthquake, and have lived there continuously ever since. Annual and sub-annual banding was clear, and the annual cyclicity of the major bands was verified with oxygen isotope analysis. There are no changes in growth corresponding to 2004. Trace element scans provided a wealth of information on the evolution of this earthquake-impacted wetland. Barium, Strontium and Manganese all showed strong annual cyclicity. From the analysis of older specimens, we interpret the high peaks of the Ba signal as reflecting soil erosion-Ba peaks are large immediately after the earthquake, then they diminish through time. Sr is likely a temperature signal, and Mn reflects runoff. Minor peaks in Cu, As and Pb probably reflect

  4. Improved Process control of wood waste fired boilers

    SciTech Connect

    Process Control Solutions, Inc.

    2004-01-30

    This project's principal aim was the conceptual and feasibility stage development of improved process control methods for wood-waste-fired water-tube boilers operating in industrial manufacturing applications (primarily pulp and paper). The specific objectives put forth in the original project proposal were as follows: (1) fully characterize the wood-waste boiler control inter-relationships and constraints through data collection and analysis; (2) design an improved control architecture; (3) develop and test an appropriate control and optimization algorithm; and (4) develop and test a procedure for reproducing the approach and deriving the benefits on similar pulp and paper wood-waste boilers. Detailed tasks were developed supporting these objectives.

  5. Kinetics of pulp mill effluent treatment by ozone-based processes.

    PubMed

    Ko, Chun-Han; Hsieh, Po-Hung; Chang, Meng-Wen; Chern, Jia-Ming; Chiang, Shih-Min; Tzeng, Chewn-Jeng

    2009-09-15

    The wastewaters generated from wood pulping and paper production processes are traditionally treated by biological and physicochemical processes. In order to reduce chemical oxygen demand (COD) and color to meet increasingly strict discharge standards, advanced oxidation processes (AOPs) are being adapted as polishing treatment units. Various ozone-based processes were used in this study to treat simulated wastewaters prepared from black liquor from a hardwood Kraft pulp mill in Taiwan. The experimental results showed that the COD and color were primarily removed by direct ozone oxidation and activated carbon adsorption. While the addition of activated carbon could enhance the COD and color removal during ozonation, the addition of hydrogen peroxide improved the color removal only. For the various ozone-based treatment processes, kinetic models were developed to satisfactorily predict the COD and color removal rates. According to the kinetic parameters obtained from the various ozone-based processes, the enhanced COD and color removal of ozonation in the presence of activated carbon was attributed to the regeneration of the activated carbon by ozonation. These kinetic models can be used for reactor design and process design to treat pulping wastewater using ozone-based processes. PMID:19304380

  6. Comprehensive analysis of individual pulp fiber bonds quantifies the mechanisms of fiber bonding in paper.

    PubMed

    Hirn, Ulrich; Schennach, Robert

    2015-01-01

    The process of papermaking requires substantial amounts of energy and wood consumption, which contributes to larger environmental costs. In order to optimize the production of papermaking to suit its many applications in material science and engineering, a quantitative understanding of bonding forces between the individual pulp fibers is of importance. Here we show the first approach to quantify the bonding energies contributed by the individual bonding mechanisms. We calculated the impact of the following mechanisms necessary for paper formation: mechanical interlocking, interdiffusion, capillary bridges, hydrogen bonding, Van der Waals forces, and Coulomb forces on the bonding energy. Experimental results quantify the area in molecular contact necessary for bonding. Atomic force microscopy experiments derive the impact of mechanical interlocking. Capillary bridges also contribute to the bond. A model based on the crystal structure of cellulose leads to values for the chemical bonds. In contrast to general believe which favors hydrogen bonding Van der Waals bonds play the most important role according to our model. Comparison with experimentally derived bond energies support the presented model. This study characterizes bond formation between pulp fibers leading to insight that could be potentially used to optimize the papermaking process, while reducing energy and wood consumption. PMID:26000898

  7. Comprehensive analysis of individual pulp fiber bonds quantifies the mechanisms of fiber bonding in paper

    NASA Astrophysics Data System (ADS)

    Hirn, Ulrich; Schennach, Robert

    2015-05-01

    The process of papermaking requires substantial amounts of energy and wood consumption, which contributes to larger environmental costs. In order to optimize the production of papermaking to suit its many applications in material science and engineering, a quantitative understanding of bonding forces between the individual pulp fibers is of importance. Here we show the first approach to quantify the bonding energies contributed by the individual bonding mechanisms. We calculated the impact of the following mechanisms necessary for paper formation: mechanical interlocking, interdiffusion, capillary bridges, hydrogen bonding, Van der Waals forces, and Coulomb forces on the bonding energy. Experimental results quantify the area in molecular contact necessary for bonding. Atomic force microscopy experiments derive the impact of mechanical interlocking. Capillary bridges also contribute to the bond. A model based on the crystal structure of cellulose leads to values for the chemical bonds. In contrast to general believe which favors hydrogen bonding Van der Waals bonds play the most important role according to our model. Comparison with experimentally derived bond energies support the presented model. This study characterizes bond formation between pulp fibers leading to insight that could be potentially used to optimize the papermaking process, while reducing energy and wood consumption.

  8. Factors affecting the corrosivity of pulping liquors

    NASA Astrophysics Data System (ADS)

    Hazlewood, Patrick Evan

    Increased equipment failures and the resultant increase in unplanned downtime as the result of process optimization programs continue to plague pulp mills. The failures are a result of a lack of understanding of corrosion in the different pulping liquors, specifically the parameters responsible for its adjustment such as the role and identification of inorganic and organic species. The current work investigates the role of inorganic species, namely sodium hydroxide and sodium sulfide, on liquor corrosivity at a range of process conditions beyond those currently experienced in literature. The role of sulfur species, in the activation of corrosion and the ability of hydroxide to passivate carbon steel A516-Gr70, is evaluated with gravimetric and electrochemical methods. The impact of wood chip weathering on process corrosion was also evaluated. Results were used to identify black liquor components, depending on the wood species, which play a significant role in the activation and inhibition of corrosion for carbon steel A516-Gr70 process equipment. Further, the effect of black liquor oxidation on liquor corrosivity was evaluated. Corrosion and stress corrosion cracking performance of selected materials provided information on classes of materials that may be reliably used in aggressive pulping environments.

  9. Ethanol determination in frozen fruit pulps: an application of quantitative nuclear magnetic resonance.

    PubMed

    da Silva Nunes, Wilian; de Oliveira, Caroline Silva; Alcantara, Glaucia Braz

    2016-04-01

    This study reports the chemical composition of five types of industrial frozen fruit pulps (acerola, cashew, grape, passion fruit and pineapple fruit pulps) and compares them with homemade pulps at two different stages of ripening. The fruit pulps were characterized by analyzing their metabolic profiles and determining their ethanol content using quantitative Nuclear Magnetic Resonance (qNMR). In addition, principal component analysis (PCA) was applied to extract more information from the NMR data. We detected ethanol in all industrial and homemade pulps; and acetic acid in cashew, grape and passion fruit industrial and homemade pulps. The ethanol content in some industrial pulps is above the level recommended by regulatory agencies and is near the levels of some post-ripened homemade pulps. This study demonstrates that qNMR can be used to rapidly detect ethanol content in frozen fruit pulps and food derivatives. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26578064

  10. Survey of receiving-water environmental impacts associated with discharges from pulp mills; 1: Mill characteristics, receiving-water chemical profiles and lab toxicity tests

    SciTech Connect

    Robinson, R.D. . Dept. of Environmental Biology); Carey, J.H. . Rivers Research Branch); Solomon, K.R. ); Smith, I.R. . Water Resources Branch); Servos, M.R.; Munkittrick, K.R. . Great Lakes Lab. for Fisheries and Aquatic Sciences)

    1994-07-01

    This survey examined the relationship between environmental responses at pulp mill sites and the pulping process, effluent treatment, and bleaching technology used by pulp mills. This manuscript is the first in a series of four; it reviews the location and operating characteristics of mills included in the survey and provides background information on water chemistry that is relevant to the other components of the survey. In addition, lab 7-d toxicity tests of receiving water were conducted using fathead minnows (Pimephales promelas) and the cladoceran Ceriodaphnia dubia with water samples collected upstream and downstream of effluent discharges at 11 Canadian pulp and paper mills; these samples were collected at the same time as fish surveys were conducted. Survival of fathead minnow larvae was significantly reduced at four of the 11 downstream sites. Ceriodaphnia reproduction was significantly higher at six of the 11 downstream sites and significantly lower at two downstream sites. There were no significant effects on fathead minnow larva growth or adult Ceriodaphnia survival at any of the examined downstream sites. Negative effects in the toxicity tests were generally associated with the low dilution discharge of primary treated effluent with a previous history of acute toxicity. Fathead minnow and Ceriodaphnia tests were generally correlated with historical data on benthic macroinvertebrate community responses. Neither toxicity test predicted the physiological changes in wild fish that are presented in accompanying papers.

  11. Chemical and sensory characterization of orange (Citrus sinensis) pulp,a by-product of orange juice processing using gas-chromatography-olfactometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Volatile composition of commercial orange pulp (from Brazil and Florida, U.S.A.) were analyzed by gas chromatography-mass spectrometry (GC-MS) and GC-Olfactometry (GC-O). In both samples 72 volatiles were detected, of which 58 were identified. Odor-active compounds with high frequency of detection (...

  12. Visual versus chemical evaluation: Effects of pruning wood decomposition on soil quality in a cherry orchard (Northeast Germany).

    NASA Astrophysics Data System (ADS)

    van Dongen, Renee; Germer, Sonja; Kern, Jürgen; Stoorvogel, Jetse

    2016-04-01

    Returning crop residues to the soil is a well-known practice to keep a sustainable soil quality in agriculture. In an orchard, pruning material could be returned for soil and water conservation or could be removed for energy production. Pruning wood decomposition rates and their impact on soil quality and greenhouse-gas emissions depend on climate, soil type, land management and water availability. Changing the soil management from leaving wood prunings on soil to removing them from the orchard is expected to result in a slow but lasting change of soil quality. Therefore a quick and cost-effective technique for soil quality evaluation is needed. This study aims to compare pruning wood decomposition effects on soil quality determined by soil chemistry (pH, C/N-ratio) or by Visual Soil Examination and Evaluation (VSEE). In addition, treatments effects on soil quality were compared for sampling positions in tree rows versus interrows. In a cherry orchard (Northeast Germany) six plots were established spreading over two planting rows. At each plot, three subplots with 1x (0.55 kg/m2), 2x (1.10 kg/m2) and 10x (5.50 kg/m2) the average pruning wood rates were installed in both tree and interrows. 5 months later the soils were sampled and a Visual Soil Evaluation and Examination (VSEE) was applied. To relate wood decomposition to impacts on soil quality, wood bags were placed in each plot and were sampled in time intervals of 5 weeks (till a maximum of 20 weeks). Wood decomposition was characterized by decomposition rates and changes in carbon and nitrogen contents. To assess environmental effects, CO2, N2O and CH4 emissions or uptake from soils with different pruning rates were determined with the closed chamber method. There were no significant differences in pH and C/N-ratio between the 3 pruning rates. However, pH was significant higher in the tree row compared to the interrow for the 10-fold pruning rate. The 10-fold pruning rate had significant higher VSEE

  13. Biotechnology in the wood industry.

    PubMed

    Mai, C; Kües, U; Militz, H

    2004-02-01

    Wood is a natural, biodegradable and renewable raw material, used in construction and as a feedstock in the paper and wood product industries and in fuel production. Traditionally, biotechnology found little attention in the wood product industries, apart from in paper manufacture. Now, due to growing environmental concern and increasing scientific knowledge, legal restrictions to conventional processes have altered the situation. Biotechnological approaches in the area of wood protection aim at enhancing the treatability of wood with preservatives and replacing chemicals with biological control agents. The substitution of conventional chemical glues in the manufacturing of board materials is achieved through the application of fungal cultures and isolated fungal enzymes. Moreover, biotechnology plays an important role in the waste remediation of preservative-treated waste wood. PMID:12937955

  14. Healing process of dog dental pulp after pulpotomy and pulp covering with mineral trioxide aggregate or Portland cement.

    PubMed

    Holland, R; de Souza, V; Murata, S S; Nery, M J; Bernabé, P F; Otoboni Filho, J A; Dezan Júnior, E

    2001-01-01

    Considering several reports about the similarity between the chemical compositions of the mineral trioxide aggregate (MTA) and Portland cement (PC), the subject of this investigation was to analyze the behavior of dog dental pulp after pulpotomy and direct pulp protection with these materials. After pulpotomy, the pulp stumps of 26 roots of dog teeth were protected with MTA or PC. Sixty days after treatment, the animal was sacrificed and the specimens removed and prepared for histomorphological analysis. There was a complete tubular hard tissue bridge in almost all specimens. In conclusion, MTA and PC show similar comparative results when used in direct pulp protection after pulpotomy. PMID:11445912

  15. Management of nonprocess elements in low-effluent bleached kraft pulp mills

    SciTech Connect

    Bryant, P.S.

    1995-12-31

    Increasing environmental regulation for the discharge of chlorinated organics in bleach plant effluents has required most manufacturers in the pulp and paper industry to reduce the charge of elemental chlorine in the bleaching of kraft pulp. The best long term solution for reducing effluent pollutants from bleached kraft pulp mills is to move towards low-effluent (closed-cycle) bleaching. Closure of operating bleach plants would dramatically reduce both the volume and the pollutant concentration of pulp mill effluents. However, closing the mill creates many operational problems including a concentration build-up of nonprocess elements (NPE`s) in process streams. NPE`s usually enter the pulp process as trace constituents of wood. Recent studies have lead to a fundamental understanding of how NPE`s partition between the solid cellulose phase and the liquid aqueous phase in pulp mill process streams. This knowledge will help in the design, operation and optimization of future low-effluent bleach plants.

  16. Application of Tradescantia micronucleus assay for in-situ evaluation of potential genetic hazards from exposure to chemicals at a wood-preserving site

    SciTech Connect

    Sandhu, S.S.; Gill, B.S.; Casto, B.C.; Rice, J.W.

    1991-01-01

    In situ evaluation of biological hazards from wood preserving chemicals at a hazardous waste site using the Tradescantia micronucleus assay (Trad-MCN) is reported in the study. The chemical analysis of soil samples from the site showed high contamination with arsenic (1,292 mg/kg), chromium (1,444 mg/kg) and copper (924 mg/kg) on the surface of the drip area where wood was allowed to dry after the treatment. Exposure of Tradescantia plants grown within or adjacent to the drip area showed significantly (P=0.05) higher frequencies of micronuclei when compared to plants grown in nearby control plots. After remediation, the levels of arsenic, chromium, and copper were substantially reduced and concomitantly no genotoxic activity was observed in plants grown on-site or in plants exposed in the laboratory to a slurry of soil samples from the site. The results from the pilot study show that simple plant assays such as Trad-MCN can be used as a sentinel for environmental contamination and to assess the efficacy of clean-up efforts.

  17. Integrated control of emission reductions, energy-saving, and cost-benefit using a multi-objective optimization technique in the pulp and paper industry.

    PubMed

    Wen, Zongguo; Xu, Chang; Zhang, Xueying

    2015-03-17

    Reduction of water pollutant emissions and energy consumption is regarded as a key environmental objective for the pulp and paper industry. The paper develops a bottom-up model called the Industrial Water Pollutant Control and Technology Policy (IWPCTP) based on an industrial technology simulation system and multiconstraint technological optimization. Five policy scenarios covering the business as usual (BAU) scenario, the structural adjustment (SA) scenario, the cleaner technology promotion (CT) scenario, the end-treatment of pollutants (EOP) scenario, and the coupling measures (CM) scenario have been set to describe future policy measures related to the development of the pulp and paper industry from 2010-2020. The outcome of this study indicates that the energy saving amount under the CT scenario is the largest, while that under the SA scenario is the smallest. Under the CT scenario, savings by 2020 include 70 kt/year of chemical oxygen demand (COD) emission reductions and savings of 7443 kt of standard coal, 539.7 ton/year of ammonia nitrogen (NH4-N) emission reductions, and savings of 7444 kt of standard coal. Taking emission reductions, energy savings, and cost-benefit into consideration, cleaner technologies like highly efficient pulp washing, dry and wet feedstock preparation, and horizontal continuous cooking, medium and high consistency pulping and wood dry feedstock preparation are recommended. PMID:25692210

  18. Final Technical Report Steam Cycle Washer for Unbleached Pulp

    SciTech Connect

    Starkey, Yvonne; Salminen, Reijo; Karlsnes, Andy

    2008-09-22

    Project Abstract for “Steam Cycle Washer for Unbleached Pulp” When completed, the patented SC Washer will provide an innovative, energy efficient demonstration project to wash unbleached pulp using a pressure vessel charged with steam. The Port Townsend Paper Corporation’s pulp mill in Port Townsend, WA was initially selected as the host site for conducting the demonstration of the SCW. Due to 2006 and 2007 delays in the project caused by issues with 21st Century Pulp & Paper, the developer of the SCW, and the 2007 bankruptcy proceedings and subsequent restructuring at Port Townsend Paper, the mill can no longer serve as a host site. An alternate host site is now being sought to complete the commercial demonstration of the Steam Cycle Washer for Unbleached Pulp. Additionally, estimated costs to complete the project have more than doubled since the initial estimates for the project were completed in 2002. Additional grant funding from DOE was sought and in July, 2008 the additional DOE funds were procured under a new DOE award, DE-PS36-08GO98014 issued to INL. Once the new host site is secured the completion of the project will begin under the management of INL. Future progress reports and milestone tracking will be completed under requirements of new DOE Award Number DE-PS36-08GO98014. The following are excerpts from the project Peer Review completed in 2006. They describe the project in some detail. Additional information can be found by reviewing DOE Award Number: DE-PS36-08GO98014. 5. Statement of Problem and Technical Barriers: The chemical pulping industry is one of the major users of fresh water in the United States. On average the industry uses over 80 tons of water to produce one ton of pulp, some states use up to 50% more (Washington 120 and Wisconsin 140). In order to process one ton of pulp using 80 tons of process water, a large amount of: • energy is used in process heat and • power is required for pumping the large volume of pulp slurries

  19. DENTAL PULP TISSUE ENGINEERING

    PubMed Central

    Demarco, FF; Conde, MCM; Cavalcanti, B; Casagrande, L; Sakai, V; Nör, JE

    2013-01-01

    Dental pulp is a highly specialized mesenchymal tissue, which have a restrict regeneration capacity due to anatomical arrangement and post-mitotic nature of odontoblastic cells. Entire pulp amputation followed by pulp-space disinfection and filling with an artificial material cause loss of a significant amount of dentin leaving as life-lasting sequelae a non-vital and weakened tooth. However, regenerative endodontics is an emerging field of modern tissue engineering that demonstrated promising results using stem cells associated with scaffolds and responsive molecules. Thereby, this article will review the most recent endeavors to regenerate pulp tissue based on tissue engineering principles and providing insightful information to readers about the different aspects enrolled in tissue engineering. Here, we speculate that the search for the ideal combination of cells, scaffolds, and morphogenic factors for dental pulp tissue engineering may be extended over future years and result in significant advances in other areas of dental and craniofacial research. The finds collected in our review showed that we are now at a stage in which engineering a complex tissue, such as the dental pulp, is no longer an unachievable and the next decade will certainly be an exciting time for dental and craniofacial research. PMID:21519641

  20. Possibilities for increasing the power generation with biomass in pulp and paper mills

    SciTech Connect

    Nousianinen, I.K.

    1995-11-01

    Even today the share of wood derived fuels in the Finnish energy supply is significant and it is higher than in any other industrialized western country. The energy content of wood derived fuels used in 1993 was equivalent to 4.36 million toe. The wood raw material used in pulp and paper mills is harvested by log-length method, in which the trees are delimbed and bucked to timber assortments at the stump prior to subsequent transport to the road side. The long-distance transport to the mills is performed by truck-trailers. Debarking takes place in debarking drums, after which the bark-free stemwood is chipped to clean chips for pulping. The bark is removed from any drum, shredded, mechanically dried and conveyed to the power plant for energy production. In order to increase the amount of wood fuel in proportion to raw wood material various integrated harvesting methods are being developed. On the other hand, the pulp and paper mills are seen as a significant potential sector for increasing the use of wood fuel in energy production. Forest management in Finland is characterized by two or three selective thinnings during rotation period. Integrated harvesting methods can be applied to the first thinnings and to the spruce-dominant regeneration fellings. The annual potential of wood fuel production with integrated harvesting methods is in the first thinnings 0.9-1.2 million toe and in the spruce-dominant regeneration fellings 0.6-0.8 million toe. The increased amount of wood fuel allows mills either to decrease the amount of purchased fuel or with new power plant technologies the amount of purchased power. In the typical pulp and paper mills the energy content of additional wood fuel produced with integrated harvesting methods can be 50-60 MW. By pressurized gasification of bark and additional wood fuel, by integrated methods and from other mills, the power generation can be increased with 70-90 MW.

  1. Pyrolysis of Wood and Bark in an Auger Reactor: Physical Properties and Chemical Analysis of the Produced Bio-oils

    SciTech Connect

    Ingram, L.; Mohan, D.; Bricka, M.; Steele, P.; Strobel, D.; Crocker, D.; Mitchell, B.; Mohammed, J.; Cantrell, K.; Pittman, C. U. Jr.

    2008-01-01

    Bio-oil was produced at 450C by fast pyrolysis in a continuous auger reactor. Four feed stocks were used: pine wood, pine bark, oak wood, and oak bark. After extensive characterization of the whole bio-oils and their pyrolytic lignin-rich ethyl acetate fractions by gas chromatography/mass spectrometry (GC/MS), gel permeation chromatography (GPC), calorific values, viscosity dependences on shear rates and temperatures, elemental analyses, {sup 1}H and {sup 13}C NMR spectroscopy, water analyses, and ash content, these bio-oils were shown to be comparable to bio-oils produced by fast pyrolysis in fluidized bed and vacuum pyrolysis processes. This finding suggests that portable auger reactors might be used to produce bio-oil at locations in forests to generate bio-oil on-site for transport of the less bulky bio-oil (versus raw biomass) to biorefineries or power generation units. The pyrolysis reported herein had lower heat transfer rates than those achieved in fluidized bed reactors, suggesting significant further improvements are possible.

  2. Novel Pulping Technology: Directed Green Liquor Utilization (D-GLU) Pulping

    SciTech Connect

    Lucian A. Lucia

    2005-11-15

    The general objectives of this new project are the same as those described in the original proposal. Conventional kraft pulping technologies will be modified for significant improvements in pulp production, such as strength, bleachability, and yield by using green liquor, a naturally high, kraft mill-derived sulfidity source. Although split white liquor sulfidity and other high sulfidity procedures have the promise of addressing several of the latter important economic needs of pulp mills, they require considerable engineering/capital retrofits, redesigned production methods, and thus add to overall mill expenditures. Green liquor use, however, possesses the required high sulfidity to obtain in general the benefits attributable to higher sulfidity cooking, without the required capital constraints for implementation. Before introduction of green liquor in our industrial operations, a stronger understanding of its fundamental chemical interaction with the lignin and carbohydrates in US hardwood and softwoods must be obtained. In addition, its effect on bleachability, enhancement of pulp properties, and influence on the overall energy and recovery of the mill requires further exploration before the process witnesses widespread mill use in North America. Thus, proof of principle will be accomplished in this work and the consequent effect of green liquor and other high sulfide sources on the pulping and bleaching operations will be explored for US kraft mills. The first year of this project will generate the pertinent information to validate its ability for implementation in US pulping operations, whereas year two will continue this work while proceeding to analyze pulp bleachability and final pulp/paper properties and develop a general economic and feasibility analysis for its eventual implementation in North America.

  3. Industrial uses of wood char

    SciTech Connect

    Kumar, M.; Gupta, R.C.

    1998-08-01

    The quality and feasibility of wood char utilization in various industries are reported. Wood char provides fuel not only for cooking and domestic heating but also for many industrial purposes, such as manufacture of iron and some ferro-alloys, recovery of gold and other nonferrous metals from their leached solutions, manufacture of chemicals and medicines, burning of bricks and glass, and removal of toxic substances from their solutions. The selection of wood char for these purposes is made on the basis of its properties, such as chemical composition, reactivity, heating value, electrical resistivity, adsorption capacity, and strength.

  4. Wood stains

    MedlinePlus

    The harmful substances in wood stains are hydrocarbons, or substances that contain only carbon and hydrogen. Other harmful ingredients may include: Alcohol Alkanes Cyclo alkanes Glycol ether Corrosives, such as sodium ...

  5. High-energy electron irradiation of annual plants (bagasse) for an efficient production of chemi-mechanical pulp fibers

    NASA Astrophysics Data System (ADS)

    Pathak, Shailesh; Ray, A. K.; Großmann, Harald; Kleinert, Rene

    2015-12-01

    The paper industry is one of the largest consumers of energy and energy consumption has been increased several times in last few decades. Bagasse chemical pulping has very low yield about 45-55% and also generates high pollution load in the effluent as compared to mechanical pulping, g. Thermo-mechanical pulp (TMP). On the other hand,-->e.g. thermo-mechanical pulp (TMP). On the other hand, the specific energy consumption is very high for TMP pulps. ETMP (Energy efficient Thermo-Mechanical Pulping) or ECTMP (Energy efficient Chemi-Thermo Mechanical Pulping) is an innovative idea for reducing the energy demand in TMP refining. In the present investigation, energy efficient mechanical pulping potential of bagasse was studied using TMP, CTMP and ECTMP pulping methodology with electron irradiation pretreatment. It is evident from the results that more than 50% energy saving potential of irradiation pre-treatment was achieved.

  6. Magnet options for sensors for the pulp and paper industry

    SciTech Connect

    Green, M.A.; Barale, P.J.; Fong, C.G.; Luft, P.A.; Reimer, J.A.; Yahnke, M.S.

    2001-05-05

    The Lawrence Berkeley National Laboratory (LBNL) has been developing sensors for the pulp and paper industry that uses a magnetic field. The applications for magnetic sensors that have studied include (1) sensors for the measurement of the water and ice content of wood chips entering the pulping mill, (2) sensors for measuring the water content and other constituents of the black liquor leaving the paper digester, and (3) sensors for measuring paper thickness and water content as the paper is being processed. These tasks can be done using nuclear magnetic resonance (NMR). The magnetic field used for doing the NMR can come from either permanent magnets or superconducting magnets. The choice of the magnet is dependent on a number of factors, which include the size of the sample and field strength needed to do the sensing task at hand. This paper describes some superconducting magnet options that can be used in the pulp and paper industry.

  7. Current fungal biotechnologies: Guidelines useful for pulping and bleaching

    SciTech Connect

    Kirk, T.K.

    1996-10-01

    This symposium deals with the potential use of fungi in pulping wood and bleaching pulp. The fungi useful in this regard are higher basidiomycetes, which are nature`s major degraders of lignin. Their ligninolytic enzyme systems were discovered 14 years ago, and have been studied intensely since then. However, neither these enzymes nor the fungi themselves have been harnessed commercially in biotechnological processes-with the exception that some of the fungi are grown as food. Using the fungi in pulp manufacturing processes, therefore, must be approached without the benefit of direct guidelines, which increases the uncertainty and risk. It is instructive, therefore, to review current commercial fungal-based bio-technologies, components of which provide information useful to the development and evaluation of proposed processes. This paper will briefly review existing types of biotechnical processes that are based on filamentous fungi, and discuss how that information is being used to guide development of new processes for biopulping and biobleaching.

  8. Magnet options for sensors for the pulp and paper industry

    NASA Astrophysics Data System (ADS)

    Green, M. A.; Barale, P. J.; Fong, C. G.; Luft, P. A.; Reimer, J. A.; Yahnke, M. S.

    2002-05-01

    The Lawrence Berkeley National Laboratory (LBNL) has been developing sensors for the pulp and paper industry that use a magnetic field. The applications for magnetic sensors that have been studied include 1) sensors for the measurement of the water and ice content of wood chips entering the pulping mill, 2) sensors for measuring the water content and other constituents of the black liquor leaving the paper digester, and 3) sensors for measuring paper thickness and water content as the paper is being processed. These tasks can be done using nuclear magnetic resonance (NMR). The magnetic field used for doing the NMR can come from either permanent magnets or superconducting magnets. The choice of the magnet is dependent on a number of factors, which include the size of the sample and field strength needed to do the sensing task at hand. This paper describes some superconducting magnet options that can be used in the pulp and paper industry.

  9. Avoiding total reduced sulfur (TRS) emissions from sodium sulfite pulping recovery processes

    SciTech Connect

    Norman, J.C.; Sell, N.J. ); Ciriacks, J.C. )

    1990-06-01

    This paper reports that one of the current trends in paper-making with cellulose pulping is the use of high-yield processes. With yields greater than 65%, these processes include mechanical pulps (groundwood and thermomechanical pulps or TMP), and semichemical types (chemi-TMP or CTMP). Groundwood and TMP make up about 10% of North American pulp production. Semichemical pulp makes up about 7% and is mostly used for corrugating medium. High-yield pulping for linerboard, particularly using the alkaline sulfite process, is also likely to be used in the future. High-yield pulping is based primarily on the sulfite process using mostly sodium-based chemicals. A disadvantage of this process is the unavailability of a recovery system for the inorganic pulping chemicals. Generally, mills have not accepted any particular recovery system for this process. For this and other reasons, sulfite processes constitute only 3-4% of the total North American pulp production. If high-yield processes continue to increase in popularity, a sodium sulfite chemical recovery system will be needed. A number of chemical recovery systems have been developed in the past 30 years for sodium-based sulfite pulping processes, with most of the mills successfully using this process located in Scandinavia.

  10. Preparation of clinker from paper pulp industry wastes.

    PubMed

    Buruberri, Leire H; Seabra, M P; Labrincha, J A

    2015-04-01

    The production of paper pulp by the Kraft method generates considerable amounts of wastes. Namely, lime mud generated in the recovery circuit of chemical reagents, biological sludge from the wastewater treatment of wood digestion process and fly ash collected in the fluidized bed combustor used to generate electricity from biomass burning. The final destination of such wastes is an important concern, since environmental regulations are becoming stricter regarding their landfill. Driven by this fact, industries are looking for more sustainable solutions, such as the recycling in distinct products. This work tested these wastes as secondary raw materials to produce clinker/cement that was then experienced in mortar formulations. The first step involved the residues detailed characterization and a generated amounts survey. Then, specific but simple steps were suggested, aiming to facilitate transport and manipulation. Distinct blends were prepared and fired in order to get belitic and Portland clinkers. The Portland clinkers were processed at lower temperatures than the normally used in the industry due to the presence of mineralizing impurities in some wastes. Belite-based cements were used to produce mortars that developed satisfactory mechanical strength and did not reveal signs of deterioration or durability weaknesses. PMID:25590818

  11. High-alkali low-temperature polysulfide pulping (HALT) of Scots pine.

    PubMed

    Paananen, Markus; Sixta, Herbert

    2015-10-01

    High-alkali low-temperature polysulfide pulping (HALT) was effectively utilised to prevent major polysaccharide losses while maintaining the delignification rate. A yield increase of 6.7 wt% on wood was observed for a HALT pulp compared to a conventionally produced kappa number 60 pulp with comparable viscosity. Approximately 70% of the yield increase was attributed to improved galactoglucomannan preservation and 30% to cellulose. A two-stage oxygen delignification sequence with inter-stage peroxymonosulphuric acid treatment was used to ensure delignification to a bleachable grade. In a comparison to conventional pulp, HALT pulp effectively maintained its yield advantage. Diafiltration trials indicate that purified black liquor can be directly recycled, as large lignin fractions and basically all dissolved polysaccharides were separated from the alkali-rich BL. PMID:26119050

  12. Dental Pulp Testing: A Review

    PubMed Central

    Chen, Eugene; Abbott, Paul V.

    2009-01-01

    Dental pulp testing is a useful and essential diagnostic aid in endodontics. Pulp sensibility tests include thermal and electric tests, which extrapolate pulp health from sensory response. Whilst pulp sensibility tests are the most commonly used in clinical practice, they are not without limitations and shortcomings. Pulp vitality tests attempt to examine the presence of pulp blood flow, as this is viewed as a better measure of true health than sensibility. Laser Doppler flowmetry and pulse oximetry are examples of vitality tests. Whilst the prospect is promising, there are still many practical issues that need to be addressed before vitality tests can replace sensibility tests as the standard clinical pulp diagnostic test. With all pulp tests, the results need to be carefully interpreted and closely scrutinised as false results can lead to misdiagnosis which can then lead to incorrect, inappropriate, or unnecessary treatment. PMID:20339575

  13. Effects of wood fiber surface chemistry on strength of wood-plastic composites

    NASA Astrophysics Data System (ADS)

    Migneault, Sébastien; Koubaa, Ahmed; Perré, Patrick; Riedl, Bernard

    2015-07-01

    Because wood-plastic composites (WPC) strength relies on fiber-matrix interaction at fiber surface, it is likely that fiber surface chemistry plays an important role in WPC strength development. The objective of the present study is to investigate the relationships between fiber surface chemical characteristics and WPC mechanical properties. Different fibers were selected and characterized for surface chemical characteristics using X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (FTIR). WPC samples were manufactured at 40% fiber content and with six different fibers. High density polyethylene was used as matrix and maleated polyethylene (MAPE) was used as compatibility agent. WPC samples were tested for mechanical properties and fiber-matrix interface was observed with scanning electron microscope. It was found WPC strength decreases as the amount of unoxidized carbon (assigned to lignin and extractives) measured with XPS on fiber surface increases. In the opposite case, WPC strength increases with increasing level of oxidized carbon (assigned to carbohydrates) on fiber surface. The same conclusions were found with FTIR where WPC strength decreases as lignin peaks intensity increases. Esterification reaction of fibers with MAPE occurs on polar sites of carbohydrates, such as hydroxyls (Osbnd H). Thus, fibers with carbohydrates-rich surface, such as cellulose pulp, produced stronger WPC samples. Other factors such as mechanical interlocking and fiber morphology interfered with the effects of fiber surface chemistry.

  14. Assessment of electrochemical and chemical coagulation as post-treatment for the effluents of a UASB reactor treating cellulose pulp mill wastewater.

    PubMed

    Buzzini, A P; Motheo, A J; Pires, E C

    2005-01-01

    This paper presents results from exploratory experiments to test the technical feasibility of electrolytic treatment and coagulation followed by flocculation and sedimentation as post-treatment for the effluent of an UASB reactor treating simulated wastewater from an unbleached Kraft pulp mill. The electrolytic treatment provided up to 67% removal of the remaining COD and 98% of color removal. To achieve these efficiencies the energy consumption ranged from 14 Wh x l(-1) to 20 Wh x l(-1). The coagulation-flocculation treatment followed by settling required 350-400 mg x l(-1) of aluminium sulfate. The addition of a high molecular weight cationic polymer enhanced both COD and color removal. Both post-treatment processes are technically feasible. PMID:16180426

  15. Durability of pulp fiber-cement composites

    NASA Astrophysics Data System (ADS)

    Mohr, Benjamin J.

    Wood pulp fibers are a unique reinforcing material as they are non-hazardous, renewable, and readily available at relatively low cost compared to other commercially available fibers. Today, pulp fiber-cement composites can be found in products such as extruded non-pressure pipes and non-structural building materials, mainly thin-sheet products. Although natural fibers have been used historically to reinforce various building materials, little scientific effort has been devoted to the examination of natural fibers to reinforce engineering materials until recently. The need for this type of fundamental research has been emphasized by widespread awareness of moisture-related failures of some engineered materials; these failures have led to the filing of national- and state-level class action lawsuits against several manufacturers. Thus, if pulp fiber-cement composites are to be used for exterior structural applications, the effects of cyclical wet/dry (rain/heat) exposure on performance must be known. Pulp fiber-cement composites have been tested in flexure to examine the progression of strength and toughness degradation. Based on scanning electron microscopy (SEM), environmental scanning electron microscopy (ESEM), energy dispersive spectroscopy (EDS), a three-part model describing the mechanisms of progressive degradation has been proposed: (1) initial fiber-cement/fiber interlayer debonding, (2) reprecipitation of crystalline and amorphous ettringite within the void space at the former fiber-cement interface, and (3) fiber embrittlement due to reprecipitation of calcium hydroxide filling the spaces within the fiber cell wall structure. Finally, as a means to mitigate kraft pulp fiber-cement composite degradation, the effects of partial portland cement replacement with various supplementary cementitious materials (SCMs) has been investigated for their effect on mitigating kraft pulp fiber-cement composite mechanical property degradation (i.e., strength and toughness

  16. Development of hemicelluloses biorefineries for integration into kraft pulp mills

    NASA Astrophysics Data System (ADS)

    Ajao, Olumoye Abiodun

    The development and wide spread acceptance of production facilities for biofuels, biochemicals and biomaterials is an important condition for reducing reliance on limited fossil resources and transitioning towards a global biobased economy. Pulp and paper mills in North America are confronted with high energy prices, high production costs and intense competition from emerging economies and low demand for traditional products. Integrated forest biorefineries (IFBR) have been proposed as a mean to diversify their product streams, increase their revenue and become more sustainable. This is feasible because they have access to forest biomass, an established feedstock supply chain and wood processing experience. In addition, the integration of a biorefinery process that can share existing infrastructure and utilities on the site of pulp mill would significantly lower investment cost and associated risks. Kraft pulping mills are promising receptor processes for a biorefinery because they either possess a prehydrolysis step for extracting hemicelluloses sugars prior to wood pulping or it can be added by retrofit. The extracted hemicelluloses could be subsequently transformed into a wide range of value added products for the receptor mill. To successfully implement hemicelluloses biorefinery, novel processes that are technically and economically feasible are required. It is necessary to identify products that would be profitable, develop processes that are energy efficient and the receptor mill should be able to supply the energy, chemicals and material demands of the biorefinery unit. The objective of this thesis is to develop energy efficient and economically viable hemicelluloses biorefineries for integration into a Kraft pulping process. A dissolving pulp mill was the reference case study. The transformation of hemicellulosic sugars via a chemical and biochemical conversion pathway, with furfural and ethanol as representative products for each pathway was studied. In

  17. Vertical distribution of AhR-activating compounds in sediments contaminated by modernized pulp and paper industry.

    PubMed

    Ratia, H; Oikari, A

    2014-03-01

    Increased ethoxyresorufin-O-deethylase (EROD) activity is a sensitive biomarker of exposure to the chemicals which activate the aryl hydrocarbon receptor (AhR) and induce the cytochrome P450 system, such as many polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs). Pulp bleaching was one of the main sources of PCDDs and PCDFs until elemental chlorine free (ECF) and total chlorine free bleaching processes since 1990s have remarkably decreased but not completely eliminate discharges of these chemicals. In addition, historically contaminated sediments may act as a source of these persistent contaminants. In this study, the contamination history and recovery of a watercourse heavily loaded by the chemical wood industry were studied by analyzing PCDDs, PCDFs and PCBs from vertical sediment samples and by measuring hepatic EROD activity from rainbow trout intraperitoneally dosed with the sediment extracts. No PCDDs or PCDFs were found above the chromatographic limit of detection from the study area and only small amounts of PCB congeners 101, 138, 153, and 180 were present. No increased EROD activity was observed in fish indicating the absence of any AhR-activating compounds in the surface sediment, to about 15 cm depth, representing about the last 20 years when kraft pulping and ECF bleaching with activated wastewater treatment have been used. It can be concluded that nowadays organochlorines and other AhR-ligands do not harm the previously heavily polluted watercourse. PMID:24361517

  18. Fate and movement of azaarenes and their anaerobic biotransformation products in an aquifer contaminated by wood-treatment chemicals

    USGS Publications Warehouse

    Pereira, W.E.; Rostad, C.E.; Updegraff, D.M.; Bennett, J.L.

    1987-01-01

    Infiltration of wastes containing creosote and pentachlorophenol from surface impoundments at an abandoned wood-treatment facility near Pensacola, Florida, resulted in contamination of the underlying sand and gravel aquifer. Pond sludges and sediments near the source were contaminated with 2- to 5-ring azaarenes having log Kow values of from 2.0 to 5.6. However, the ground water contained only azaarenes and their oxygenated and methylated derivatives having log Kow values of less than 3.5. These compounds also were present in coal tar-contaminated ground water at a site near St. Louis Park, Minnesota. Laboratory anaerobic degradation studies and on-site observations indicated that oxygenated azaarenes probably were biotransformation products of reactions mediated by indigenous microbial populations. Microbial N-methylation, C-methylation and O-methylation reactions are reported here for the first time. In the presence of nutrients and carbon sources such as acetate and propionate, all azaarenes studied were either partially or completely degraded. Evidence for the microbial degradation of azaarenes in ground water from anaerobic zones is presented. Oxygenated azaarenes were relatively more water-soluble, mobile and persistent in hydrogeologic environments. ?? 1987.

  19. Attraction and electroantennogram responses of male Mediterranean fruit fly to volatile chemicals from Persea, Litchi and Ficus wood.

    PubMed

    Niogret, Jerome; Montgomery, Wayne S; Kendra, Paul E; Heath, Robert R; Epsky, Nancy D

    2011-05-01

    Trimedlure is the most effective male-targeted lure for the Mediterranean fruit fly, Ceratitis capitata (Wiedemann). A similar response is elicited by plant substances that contain α-copaene, a naturally-occurring sesquiterpene. α-Copaene is a complex, highly-volatile, widely-distributed plant compound, and male C. capitata respond to material from both hosts (e.g., Litchi chinensis) and non-hosts (e.g., Ficus benjamina) that contain α-copaene. Avocado, Persea americana, recently was found to contain varying amounts of α-copaene in the bark and underlying cambial tissue. Short-range attraction bioassays and electroantennography (EAG) were used to quantify responses of sterile male C. capitata to samples of rasped wood from four avocado genotypes, L. chinensis, and F. benjamina. Gas chromatography-mass spectral (GC-MS) analysis was used to identify and quantify the major sesquiterpenes. Attraction and EAG amplitude were correlated, with L. chinensis eliciting the highest and F. benjamina the lowest responses. Responses to the avocado genotypes were intermediate, but varied among the four types. GC-MS identified 13 sesquiterpenes, including α-copaene, from all samples. Amounts of α-copaene in volatile collections from samples (3 g) ranged from 11.8 μg in L. chinensis to 0.09 μg in F. benjamina, which correlated with short-range attraction and EAG response. α-Copaene ranged from 8.0 to 0.8 μg in the avocado genotypes, but attraction and EAG responses were not correlated with the amount of α-copaene. Differences in enantiomeric structure of the α-copaene in the different genotypes and/or presence of additional sesquiterpenes may be responsible for the variation in male response. EAG responses were correlated with the amount of several other sesquiterpenes including α-humulene, and this compound elicited a strong antennal response when tested alone. PMID:21526361

  20. Inference of chemicals that cause biological effects in treated pulp and paper mill effluent using gene expression in caged fathead minnows

    EPA Science Inventory

    Analytical chemistry techniques can identify chemicals present in the waters of the Great Lakes areas of concern, however it remains a challenge to identify those chemicals or classes of chemicals that actually cause adverse effects. Use of caged fathead minnows (Pimephales prome...

  1. Structural and chemical characterization of hardwood from tree species with applications as bioenergy feedstocks.

    PubMed

    Cetinkol, Özgül Persil; Smith-Moritz, Andreia M; Cheng, Gang; Lao, Jeemeng; George, Anthe; Hong, Kunlun; Henry, Robert; Simmons, Blake A; Heazlewood, Joshua L; Holmes, Bradley M

    2012-01-01

    Eucalypt species are a group of flowering trees widely used in pulp production for paper manufacture. For several decades, the wood pulp industry has focused research and development efforts on improving yields, growth rates and pulp quality through breeding and the genetic improvement of key tree species. Recently, this focus has shifted from the production of high quality pulps to the investigation of the use of eucalypts as feedstocks for biofuel production. Here the structure and chemical composition of the heartwood and sapwood of Eucalyptus dunnii, E. globulus, E. pillularis, E. urophylla, an E. urophylla-E. grandis cross, Corymbia citriodora ssp. variegata, and Acacia mangium were compared using nuclear magnetic resonance spectroscopy (NMR), X-ray diffraction (XRD) and biochemical composition analysis. Some trends relating to these compositions were also identified by Fourier transform near infrared (FT-NIR) spectroscopy. These results will serve as a foundation for a more comprehensive database of wood properties that will help develop criteria for the selection of tree species for use as biorefinery feedstocks. PMID:23300786

  2. Structural and Chemical Characterization of Hardwood from Tree Species with Applications as Bioenergy Feedstocks

    PubMed Central

    Çetinkol, Özgül Persil; Smith-Moritz, Andreia M.; Cheng, Gang; Lao, Jeemeng; George, Anthe; Hong, Kunlun; Henry, Robert; Simmons, Blake A.; Heazlewood, Joshua L.; Holmes, Bradley M.

    2012-01-01

    Eucalypt species are a group of flowering trees widely used in pulp production for paper manufacture. For several decades, the wood pulp industry has focused research and development efforts on improving yields, growth rates and pulp quality through breeding and the genetic improvement of key tree species. Recently, this focus has shifted from the production of high quality pulps to the investigation of the use of eucalypts as feedstocks for biofuel production. Here the structure and chemical composition of the heartwood and sapwood of Eucalyptus dunnii, E. globulus, E. pillularis, E. urophylla, an E. urophylla-E. grandis cross, Corymbia citriodora ssp. variegata, and Acacia mangium were compared using nuclear magnetic resonance spectroscopy (NMR), X-ray diffraction (XRD) and biochemical composition analysis. Some trends relating to these compositions were also identified by Fourier transform near infrared (FT-NIR) spectroscopy. These results will serve as a foundation for a more comprehensive database of wood properties that will help develop criteria for the selection of tree species for use as biorefinery feedstocks. PMID:23300786

  3. Structural and Chemical Characterization of Hardwood from Tree Species with Applications as Bioenergy Feedstocks

    SciTech Connect

    Çetinkol, Özgül Persil; Smith-Moritz, Andreia M.; Cheng, Gang; Lao, Jeemeng; George, Anthe; Hong, Kunlun; Henry, Robert; Simmons, Blake A.; Heazlewood, Joshua L.; Holmes, Bradley M.; Zabotina, Olga A.

    2012-12-28

    Eucalypt species are a group of flowering trees widely used in pulp production for paper manufacture. For several decades, the wood pulp industry has focused research and development efforts on improving yields, growth rates and pulp quality through breeding and the genetic improvement of key tree species. Recently, this focus has shifted from the production of high quality pulps to the investigation of the use of eucalypts as feedstocks for biofuel production. Here the structure and chemical composition of the heartwood and sapwood of Eucalyptus dunnii, E. globulus, E. pillularis, E. urophylla, an E. urophylla-E. grandis cross, Corymbia citriodora ssp. variegata, and Acacia mangium were compared using nuclear magnetic resonance spectroscopy (NMR), X-ray diffraction (XRD) and biochemical composition analysis. Some trends relating to these compositions were also identified by Fourier transform near infrared (FT-NIR) spectroscopy. These results will serve as a foundation for a more comprehensive database of wood properties that will help develop criteria for the selection of tree species for use as biorefinery feedstocks.

  4. WOOD SMOKE IMPACTED AIR: MUTAGENICITY AND CHEMICAL ANALYSIS OF AMBIENT AIR IN A RESIDENTIAL AREA OF JUNEAU, ALASKA (JOURNAL VERSION)

    EPA Science Inventory

    The study was undertaken to determine the bacterial mutagenicity (Ames test) and chemical characteristics of respirable particulate matter collected in the area. Fine particle concentrations for the sampling period of November 16th to January 7th ranged from 1.19 to 209.8 microgr...

  5. Boiler wood ash as a soil amendment

    SciTech Connect

    Mitchell, C.C.

    1996-12-31

    Each of the 88 pulp and paper mills in the southeastern United States produces an average of 43 t of boiler ash daily (47 US tons). Forty percent is wood ash, 5% is coal ash, and the remaining is a combination ash. An analysis of boiler ash from 14 Alabama pulp and paper mills averaged 38% CaCO3 equivalent with a dry density of 500 kg m{sup -3}. Most agricultural soils in the southeastern US require periodic application of ground limestone in order to maintain productivity. Using boiler wood ash and combination ash as an alternative to ground limestone is agronomically productive, environmentally safe, and fiscally sound for both the ash producer and the landowner/ farmer. While plant, nutrient content of ash is variable, it should be considered as an incidental source of plant nutrients for field crops. Metals and phytotoxic components are very low. Extensive research has been reported on the value and safety of wood-fired boiler ashes. Nevertheless, research and development projects continue in efforts to assure safe use of boiler wood ash as an alternative soil liming material.

  6. Integration of a kraft pulping mill into a forest biorefinery: pre-extraction of hemicellulose by steam explosion versus steam treatment.

    PubMed

    Martin-Sampedro, Raquel; Eugenio, Maria E; Moreno, Jassir A; Revilla, Esteban; Villar, Juan C

    2014-02-01

    Growing interest in alternative and renewable energy sources has brought increasing attention to the integration of a pulp mill into a forest biorefinery, where other products could be produced in addition to pulp. To achieve this goal, hemicelluloses were extracted, either by steam explosion or by steam treatment, from Eucalyptus globulus wood prior to pulping. The effects of both pre-treatments in the subsequent kraft pulping and paper strength were evaluated. Results showed a similar degree of hemicelluloses extraction with both options (32-67% of pentosans), which increased with the severity of the conditions applied. Although both pre-treatments increased delignification during pulping, steam explosion was significantly better: 12.9 kappa number vs 22.6 for similar steam unexploded pulps and 40.7 for control pulp. Finally, similar reductions in paper strength were found regardless of the type of treatment and conditions assayed, which is attributed to the increase of curled and kinked fibers. PMID:24368272

  7. GELIFICATION OF WOOD DURING COALIFICATION.

    USGS Publications Warehouse

    Hatcher, Patrick G.; Romankiw, Lisa A.; Evans, John R.

    1985-01-01

    Coalified wood was examined by SEM and CPMAS**1**3C NMR to delineate chemical and physical alterations responsible for gelification. Early coalification selectively degrades cellulosic components, preserving lignin-like components that are eventually transformed to coal. Cellular morphology persists until the chemical composition becomes uniform, at which point the cells coalesce under compaction and gelify.

  8. Development and Validation of Marker-Aided Selection Methods for Wood Property Traits in Loblolly Pine and Hybrid Poplar

    SciTech Connect

    Tuskan, G.A.

    2001-06-20

    Wood properties influence pulp and paper quality. Certainly, overall pulp yields are directly related to the cellulose content, changes in hemicellulose content are associated with changes in pulp cohesiveness, and pulping efficiency is related to lignin content. Despite the importance of wood properties on product quality, little progress has been made in improving such traits because current methods of assessing wood and fiber characteristics are time-consuming, expensive, and often imprecise. Genetic improvement of wood and fiber properties has been further hampered by the large size of trees, delayed reproductive maturity and long harvest cycles. Recent developments in molecular genetics will help overcome the physical, economic and biological constraints in assessing and improving wood properties. Genetic maps consisting of numerous molecular markers are now available for loblolly pine and hybrid poplar. Such markers/maps may be used as part of a marker-aided selection and breeding effort or to expedite the isolation and characterization of genes and/or promoters that directly control wood properties. The objectives of this project are: (1) to apply new and rapid analytical techniques for assessing component wood properties to segregating F2 progeny populations of loblolly pine and hybrid poplar, (2) to map quantitative trait loci and identify molecular markers associated with wood properties in each of the above species and (3) to validate marker-aided selection methods for wood properties in loblolly pine and hybrid poplar.

  9. Understanding the Nature and Reactivity of Residual Lignin for Improved Pulping and Bleaching Efficiency

    SciTech Connect

    Yuan-Zong Lai

    2001-11-30

    One of the most formidable challenges in kraft pulping to produce bleached chemical pulps is how to effectively remove the last 5-10% of lignin while maintaining the fiber quality. To avoid a severe fiber degradation, kraft pulping is usually terminated in the 25-30 kappa number range and then followed by an elementally chlorine free (ECF) or a totally chlorine free (TCF) bleaching sequence to reduce the environmental impacts.

  10. Characterization of the pretreatment liquor of biomass from the perennial grass, Eulaliopsis binata, for the production of dissolving pulp.

    PubMed

    Tang, Jiebin; Chen, Kefu; Huang, Fang; xu, Jun; Li, Jun

    2013-02-01

    To test a biorefinery concept, the non-wood biomass of Eulaliopsis binata was treated with dilute acid prior to dissolving pulp production at 160 °C for 30 min. The pretreatment liquor (PL) contained 42.04 g/L sugars, of which 81.46% was xylose and only 2.91% was glucose. Furfural and hydroxymethylfurfural in PL were 0.37% and 0.06%, respectively. Chemical or enzymatic hydrolysis of carbohydrates could be omitted when producing bioethanol with PL because 87.32% of the total sugars were in the form of monosaccharides. Membrane filtration with a molecular-weight cut-off of 100 Da was employed to concentrate the sugars and a concentration of 170.49 g/L was achieved. A method of zero release of the PL is proposed, which consists of ethanol production from the concentrated PL and recycling the permeate stream into the pretreatment process. PMID:23274218

  11. Biotechnology in the pulp and paper industry; A review

    SciTech Connect

    Trotter, P.C. )

    1990-05-01

    This paper reviews biotechnology in the pulp and paper industry. As to biopulping and biobleaching, little effort is being devoted to improving strength properties of pulps. However, positive results have been reported in improving tensile properties by treating mechanical pulps with white-rot organisms and in enzymatic beating of chemical pulps with hemicellulase enzymes. Papermaking is another seemingly overlooked area, although biological systems and processes have been used in the past and ought to be important still. On the other hand, waste treatment has been a stronghold of biotechnology within the industry for years. New possibilities may emerge via biotechnology for removing color and AOX from bleach plant effluents. New research on the use of white-rot organisms and soil bacteria to detoxify chlorinated organics in soils and groundwater may yield technologies that the industry can apply.

  12. Dental pulp stem cells

    PubMed Central

    Ashri, Nahid Y.; Ajlan, Sumaiah A.; Aldahmash, Abdullah M.

    2015-01-01

    Inflammatory periodontal disease is a major cause of loss of tooth-supporting structures. Novel approaches for regeneration of periodontal apparatus is an area of intensive research. Periodontal tissue engineering implies the use of appropriate regenerative cells, delivered through a suitable scaffold, and guided through signaling molecules. Dental pulp stem cells have been used in an increasing number of studies in dental tissue engineering. Those cells show mesenchymal (stromal) stem cell-like properties including self-renewal and multilineage differentiation potentials, aside from their relative accessibility and pleasant handling properties. The purpose of this article is to review the biological principles of periodontal tissue engineering, along with the challenges facing the development of a consistent and clinically relevant tissue regeneration platform. This article includes an updated review on dental pulp stem cells and their applications in periodontal regeneration, in combination with different scaffolds and growth factors. PMID:26620980

  13. Chemical Analysis and Study of Phenolics, Antioxidant Activity, and Antibacterial Effect of the Wood and Bark of Maclura tinctoria (L.) D. Don ex Steud.

    PubMed

    Lamounier, K C; Cunha, L C S; de Morais, S A L; de Aquino, F J T; Chang, R; do Nascimento, E A; de Souza, M G M; Martins, C H G; Cunha, W R

    2012-01-01

    Maclura tinctoria (L.) D. Don ex Steud. has one of the highest qualities among the coefficients for Brazilian woods (up to 9.6) and resistance rates equivalent to Indian teak (Tectona grandis). In this study, the macromolecular constituents and total phenols compounds as well as the antioxidant and antibacterial activities of this wood were evaluated. Total phenols and proanthocyanidin levels were higher in wood when compared with bark levels. The antioxidant activity of wood extracts (IC(50) = 18.7 μg/mL) was more effective than that of bark extracts (IC(50) = 20.9 μg/mL). Wood and bark extracts revealed a high potential for inhibition of aerobic and anaerobic bacteria. The bark extracts were the most active (MIC from 20 to 60 μg/mL). Both antioxidant activity and high potential for bacteria inhibition turn these extracts promising for drug formulations, especially as antibacterial agent. PMID:22454666

  14. Competitive outcomes between wood-decaying fungi are altered in burnt wood.

    PubMed

    Edman, Mattias; Eriksson, Anna-Maria

    2016-06-01

    Fire is an important disturbance agent in boreal forests where it creates a wide variety of charred and other types of heat-modified dead wood substrates, yet how these substrates affect fungal community structure and development within wood is poorly understood. We allowed six species of wood-decaying basidiomycetes to compete in pairs in wood-discs that were experimentally burnt before fungal inoculation. The outcomes of interactions in burnt wood differed from those in unburnt control wood for two species:Antrodia sinuosanever lost on burnt wood and won over its competitor in 67% of the trials compared to 40% losses and 20% wins on unburnt wood. In contrast, Ischnoderma benzoinumwon all interactions on unburnt wood compared to 33% on burnt wood. However, the responses differed depending on the identity of the competing species, suggesting an interaction between competitor and substrate type. The observed shift in competitive balance between fungal species probably results from chemical changes in burnt wood, but the underlying mechanism needs further investigation. Nevertheless, the results indicate that forest fires indirectly structure fungal communities by modifying dead wood, and highlight the importance of fire-affected dead wood substrates in boreal forests. PMID:27059863

  15. Significance of wood extractives for wood bonding.

    PubMed

    Roffael, Edmone

    2016-02-01

    Wood contains primary extractives, which are present in all woods, and secondary extractives, which are confined in certain wood species. Extractives in wood play a major role in wood-bonding processes, as they can contribute to or determine the bonding relevant properties of wood such as acidity and wettability. Therefore, extractives play an immanent role in bonding of wood chips and wood fibres with common synthetic adhesives such as urea-formaldehyde-resins (UF-resins) and phenol-formaldehyde-resins (PF-resins). Extractives of high acidity accelerate the curing of acid curing UF-resins and decelerate bonding with alkaline hardening PF-resins. Water-soluble extractives like free sugars are detrimental for bonding of wood with cement. Polyphenolic extractives (tannins) can be used as a binder in the wood-based industry. Additionally, extractives in wood can react with formaldehyde and reduce the formaldehyde emission of wood-based panels. Moreover, some wood extractives are volatile organic compounds (VOC) and insofar also relevant to the emission of VOC from wood and wood-based panels. PMID:26685670

  16. Improved Wood Properties Through Genetic Manipulation

    SciTech Connect

    2006-10-01

    This factsheet describes a research project to replacing the more chemically resistant guaiacyl (G) lignin with the less resistant hardwood guaiacyl (G)-syringyl (S) lignin genes. Achieving this genetic change would reduce the energy, chemical, and bleaching required in Kraft pulp production of softwoods.

  17. Morphology and Chemical Composition of soot particles emitted by Wood-burning Cook-Stoves: a HRTEM, XPS and Elastic backscattering Studies.

    NASA Astrophysics Data System (ADS)

    Carabali-Sandoval, G. A., Sr.; Castro, T.; Peralta, O.; De la Cruz, W.; Días, J.; Amelines, O.; Rivera-Hernández, M.; Varela, A.; Muñoz-Muñoz, F.; Policroniades, R.; Murillo, G.; Moreno, E.

    2014-12-01

    The morphology, microstructure and the chemical composition on surface of soot particles were studied by using high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and elastic backscattering spectrometry. In order to obtain freshly soot particles emitted by home-made wood-burning cook stoves, copper grids for Transmission Electron Microscope (TEM) were placed on the last two of an 8-stages MOUDI cascade impactor. The analysis of HRTEM micrographs revealed the nanostructure and the particle size of soot particles. The XPS survey spectra show a large carbon peak around 285 eV and the oxygen signal at 533 eV. Some differences observed in the carbon/oxygen (C/O) ratio of the particles probably depend on the combustion process efficiency of each cook-stove analyzed. The C-1s XPS spectra show an asymmetric broad peak and other with low intensity that corresponds to sp2 and sp3hybridization, which were fitted with a convolution using Gaussian functions. Elastic backscattering technique allows a chemical elemental analysis of samples and confirms the presence of C, O and Si observed by XPS. Additionally, the morphological properties of soot aggregates were analyzed calculating the border-based fractal dimension (Df). Particles exhibit complex shapes with high values of Df. Also, real-time absorption (σabs) and scattering (σsct) coefficients of fine (with aerodynamic diameter < 2.5 µm) soot particles were measured. The trend in σabs and σsct indicate that the cooking process has two important combustion stages which varied in its flaming strength, being vigorous in the first stage and soft in the second one.

  18. 21 CFR 872.1720 - Pulp tester.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... DENTAL DEVICES Diagnostic Devices § 872.1720 Pulp tester. (a) Identification. A pulp tester is an AC or... current transmitted by an electrode to stimulate the nerve tissue in the dental pulp. (b)...

  19. 21 CFR 872.1720 - Pulp tester.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... DENTAL DEVICES Diagnostic Devices § 872.1720 Pulp tester. (a) Identification. A pulp tester is an AC or... current transmitted by an electrode to stimulate the nerve tissue in the dental pulp. (b)...

  20. 21 CFR 872.1720 - Pulp tester.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... DENTAL DEVICES Diagnostic Devices § 872.1720 Pulp tester. (a) Identification. A pulp tester is an AC or... current transmitted by an electrode to stimulate the nerve tissue in the dental pulp. (b)...

  1. Chemical characterization of soot particles emitted by Wood-Burning Cook Stoves: A XPS and HRTEM study

    NASA Astrophysics Data System (ADS)

    Carabali, Giovanni; Peralta, Oscar; Castro, Telma; Torres, Ricardo; Ruiz, Gerardo; Molina, Luisa; Saavedra, Isabel

    2014-05-01

    The morphology, microstructure, chemical composition, and electronic structure of soot particles emitted directly from biofuel cook stoves have been studied by high resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). In order to obtain freshly emitted soot particles, copper grids for Transmission Electron Microscope (TEM) were placed on the last two of an 8-stages MOUDI cascade impactor. The analysis of HRTEM micrographs revealed the nanostructure and the particle size of soot chain. Additionally, the morphology of soot particles was analyzed calculating the border-based fractal dimension (Df). Particles sampled on the first heating stage exhibit complex shapes with high values of Df, which are present as aggregates formed by carbon ceno-spheres. The XPS survey spectrum for soot particles shows that the main particle composition is carbon. We also observed differences in the carbon/oxygen (C/O) ratio of the particles, which probably depends on the combustion process efficiency of each cook-stove analyzed. The XPS C-1s spectra show carbon with two peaks that correspond to sp2 and sp3 hybridization. Also, real-time absorption (βa) and scattering (αs) coefficients of the particles emitted by cook stoves were measured. The trend in βa and αs indicate that the cooking process has two important combustion stages which varied in its flaming strength, being vigorous in the first stage and soft in the second one.

  2. The enzymatic hydrolysis of pretreated pulp fibers predominantly involves “peeling/erosion” modes of action

    PubMed Central

    2014-01-01

    Background There is still considerable debate regarding the actual mechanism by which a “cellulase mixture” deconstructs cellulosic materials, with accessibility to the substrate at the microscopic level being one of the major restrictions that limits fast, complete cellulose hydrolysis. In the work reported here we tried to determine the predominant mode of action, at the fiber level, of how a cellulase mixture deconstructs pretreated softwood and hardwood pulp fibers. Quantitative changes in the pulp fibers derived from different pretreated biomass substrates were monitored throughout the course of enzymatic hydrolysis to see if the dominant mechanisms involved either the fragmentation/cutting of longer fibers to shorter fibers or their “peeling/delamination/erosion,” or if both cutting and peeling mechanisms occurred simultaneously. Results Regardless of the source of biomass, the type of pretreatment and the chemical composition of the substrate, under typical hydrolysis conditions (50°C, pH 4.8, mixing) longer pulp fibers (fiber length >200 μm) were rapidly broken down until a relatively constant fiber length of 130 to 160 μm was reached. In contrast, shorter fibers with an initial average fiber length of 130 to 160 μm showed no significant change in length despite their substantial hydrolysis. The fragmentation/cutting mode of deconstruction was only observed on longer fibers at early stages of hydrolysis. Although the fiber fragmentation mode of deconstruction was not greatly influenced by enzyme loading, it was significantly inhibited by glucose and was mainly observed during initial mixing of the enzyme and substrate. In contrast, significant changes in the fiber width occurred throughout the course of hydrolysis for all of the substrates, suggesting that fiber width may limit the rate and extent of cellulose hydrolysis. Conclusion It appears that, at the fiber level, pretreated pulp fibers are hydrolyzed through a two-step mode of action

  3. Oxygen consumption by conserved archaeological wood.

    PubMed

    Mortensen, Martin N; Matthiesen, Henning

    2013-07-01

    Rates of oxygen consumption have been measured over extended time periods for 29 whole samples of conserved, archaeological wood and four samples of fresh, unconserved wood, at 50% relative humidity and room temperature. Samples from the Swedish Warship Vasa and the Danish Skuldelev Viking ships are included. Most rates were close to 1 μg O2 (g wood)(-1) day(-1) and the process persisted for several years at least. Consumption of oxygen is related to change in chemical composition, which is, in turn, related to degradation. It is thus demonstrated that despite conservation, waterlogged archaeological wood continues to degrade in a museum climate. PMID:23715675

  4. Spectroscopic characteristics of ultrafiltration fractions of fulvic and humic acids isolated from an eucalyptus bleached Kraft pulp mill effluent.

    PubMed

    Duarte, Regina M B O; Santos, Eduarda B H; Duarte, Armando C

    2003-10-01

    In order to investigate the chemical heterogeneity of fulvic and humic acids previously isolated from a bleached Kraft pulp mill effluent, a sequential ultrafiltration (UF) scheme through four polyethersulphone membranes was applied. The unfractionated fulvic and humic acids and their fractions were characterized by UV-VIS, synchronous fluorescence (with Deltalambda=60 nm) and FTIR spectroscopies. The FTIR spectra were compared with those of lignin isolated from Eucalyptus globulus wood and from the black liquor of a Kraft pulping process. The results highlighted that fulvic acids fractions of low molecular sizes contain more lignin derived phenolic units, while those of higher molecular size exhibit a higher content of carbohydrate structures. However, the shift observed in the UV-VIS absorbance and fluorescence intensity towards higher wavelength, suggests a higher degree of conjugation of pi-bonds in the fractions of highest molecular sizes. In what concerns the humic acids size fractions, the FTIR spectra did not exhibit major differences but, as observed for the fulvic acids' fractions, UV-VIS and synchronous fluorescence spectra also suggest a higher degree of conjugation of pi-bonds in the fractions with the highest molecular sizes. It was also observed that the fulvic and humic acids fractions of the same molecular size, operationally defined by the UF process, exhibit major differences in their spectroscopic features. PMID:12946888

  5. Wood colors and their coloring matters: a review.

    PubMed

    Yazaki, Yoshikazu

    2015-03-01

    A number of colored specialty woods, such as ebony, rosewood, mahogany and amboyna, and commercially important woods, such as morus, logwood, Brazilwood, Japanese yellowwood, blackwood, kwila, red beech and myrtle beech, exhibit a wide range of colors from black, violet, dark red, reddish brown, to pale yellow. These colors are not only due to colored pigments contained in extractives from those woods but also to insoluble polymers. Wood and bark from many species of both hardwood and softwood trees contain many types of flavonoid compounds. Research on flavonoids has been conducted mainly from two points of view. The first is chemotaxonomy with flavonoid compounds as taxonomic markers, and the second relates to the utilization of woods for pulp and paper and the use of tannins from bark for wood adhesives. Most chemotaxonomic studies have been conducted on flavonoids in the extracts from softwoods such as Podocarpus, Pinus, Pseudotsuga, Larix, Taxus, Libocedrus, Tsuja, Taxodium, Sequoia, Cedrus, Tsuga, Abies and Picea. Hardwood chemotaxonomic studies include those on Prunus and Eucalyptus species. Studies on flavonoids in pulp and paper production were conducted on Eucalyptus woods in Australia and woods from Douglas fir in the USA and larch in Japan. Flavonoids as tannin resources from black wattle tannin and quebracho tannin have been used commercially as wood adhesives. Flavonoids in the bark from radiata pine and southern pine, from western and eastern hemlock, southern red oak and Quercus dentata are also discussed. In addition, the distribution of flavonoids among tree species is described, as is the first isolation of rare procyanidin glycosides in nature. PMID:25924540

  6. Is Pulp Inflammation a Prerequisite for Pulp Healing and Regeneration?

    PubMed Central

    Goldberg, Michel; Njeh, Akram; Uzunoglu, Emel

    2015-01-01

    The importance of inflammation has been underestimated in pulpal healing, and in the past, it has been considered only as an undesirable effect. Associated with moderate inflammation, necrosis includes pyroptosis, apoptosis, and nemosis. There are now evidences that inflammation is a prerequisite for pulp healing, with series of events ahead of regeneration. Immunocompetent cells are recruited in the apical part. They slide along the root and migrate toward the crown. Due to the high alkalinity of the capping agent, pulp cells display mild inflammation, proliferate, and increase in number and size and initiate mineralization. Pulp fibroblasts become odontoblast-like cells producing type I collagen, alkaline phosphatase, and SPARC/osteonectin. Molecules of the SIBLING family, matrix metalloproteinases, and vascular and nerve mediators are also implicated in the formation of a reparative dentinal bridge, osteo/orthodentin closing the pulp exposure. Beneath a calciotraumatic line, a thin layer identified as reactionary dentin underlines the periphery of the pulp chamber. Inflammatory and/or noninflammatory processes contribute to produce a reparative dentinal bridge closing the pulp exposure, with minute canaliculi and large tunnel defects. Depending on the form and severity of the inflammatory and noninflammatory processes, and according to the capping agent, pulp reactions are induced specifically. PMID:26538825

  7. Characterization of Palo Podrido, a Natural Process of Delignification in Wood

    PubMed Central

    Agosin, Eduardo; Blanchette, Robert A.; Silva, Herman; Lapierre, Catherine; Cease, Kory R.; Ibach, Rebecca E.; Abad, André R.; Muga, Pedro

    1990-01-01

    Chemical and morphological changes of incipient to advanced stages of palo podrido, an extensively delignified wood, and other types of white rot decay found in the temperate forests of southern Chile were investigated. Palo podrido is a general term for white rot decay that is either selective or nonselective for the removal of lignin, whereas palo blanco describes the white decayed wood that has advanced stages of delignification. Selective delignification occurs mainly in trunks of Eucryphia cordifolia and Nothofagus dombeyi, which have the lowest lignin content and whose lignins have the largest amount of β-aryl ether bonds and the highest syringyl/guaiacyl ratio of all the native woods included in this study. A Ganoderma species was the main white rot fungus associated with the decay. The structural changes in lignin during the white rot degradation were examined by thioacidolysis, which revealed that the β-aryl ether-linked syringyl units were more specifically degraded than the guaiacyl ones, particularly in the case of selective delignification. Ultrastructural studies showed that the delignification process was diffuse throughout the cell wall. Lignin was first removed from the secondary wall nearest the lumen and then throughout the secondary wall toward the middle lamella. The middle lamella and cell corners were the last areas to be degraded. Black manganese deposits were found in some, but not all, selectively delignified samples. In advanced stages of delignification, almost pure cellulose could be found, although with a reduced degree of polymerization. Cellulolytic enzymes appeared to be responsible for depolymerization. A high brightness and an easy refining capacity were found in an unbleached pulp made from selectively delignified N. dombeyi wood. Its low viscosity, however, resulted in poor resistance properties of the pulp. The last stage of degradation (i.e., decomposition of cellulose-rich secondary wall layers) resulted in a gelatinlike

  8. 21 CFR 872.1720 - Pulp tester.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... DENTAL DEVICES Diagnostic Devices § 872.1720 Pulp tester. (a) Identification. A pulp tester is an AC or... current transmitted by an electrode to stimulate the nerve tissue in the dental pulp. (b) Classification... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Pulp tester. 872.1720 Section 872.1720 Food...

  9. Characterization of active paper packaging incorporated with ginger pulp oleoresin

    NASA Astrophysics Data System (ADS)

    Wiastuti, T.; Khasanah, L. U.; Atmaka Kawiji, W.; Manuhara, G. J.; Utami, R.

    2016-02-01

    Utilization of ginger pulp waste from herbal medicine and instant drinks industry in Indonesia currently used for fertilizer and fuel, whereas the ginger pulp still contains high oleoresin. Active paper packaging were developed incorporated with ginger pulp oleoresin (0%, 2%, 4%, and 6% w/w). Physical (thickness, tensile strength, and folding endurance, moisture content), sensory characteristics and antimicrobial activity of the active paper were evaluated. Selected active paper then were chemically characterized (functional groups). The additional of ginger pulp oleoresin levels are reduced tensile strength, folding endurance and sensory characteristic (color, texture and overall) and increased antimicrobial activity. Due to physical, sensory characteristic and antimicrobial activity, active paper with 2% ginger pulp oleoresin incorporation was selected. Characteristics of selected paper were 9.93% of water content; 0.81 mm of thickness; 0.54 N / mm of tensile strength; 0.30 of folding endurance; 8.43 mm inhibits the growth of Pseudomonas fluorescence and 27.86 mm inhibits the growth of Aspergillus niger (antimicrobial activity) and neutral preference response for sensory properties. For chemical characteristic, selected paper had OH functional group of ginger in 3422.83 cm-1 of wave number and indicated contain red ginger active compounds.

  10. Microbial and enzymatic control of pitch in the pulp and paper industry.

    PubMed

    Gutiérrez, Ana; del Río, José C; Martínez, Angel T

    2009-04-01

    Pitch control is an important aspect in pulp and paper manufacture, and the first example where microbial biotechnology provided successful solutions in this industrial sector. Triglycerides cause deposits in softwood mechanical pulping, and both microbial and enzymatic products have been commercialized to be applied on wood and pulp, respectively. The former are based on colorless strains of sapstain fungi. The latter are improved lipases, including thermostable variants from directed evolution. These enzymes are among the additives of choice in pulping of high-resin-content softwoods. However, lipases are not useful when pitch originates from other lipids, such as steroids and terpenes, and the sapstain inocula are also only partially effective. In the search for stronger biocatalysts to degrade recalcitrant lipids, the potential of white-rot fungi and their enzymes has been demonstrated. When inocula of these fungi are used, wood treatment must be controlled to avoid cellulose degradation. However, the efficiency and selectivity of the laccase-mediator system permits its integration as an additional bleaching stage. A double benefit can be obtained from these treatments since pitch is controlled at the same time that residual lignin is removed facilitating the implementation of totally chlorine free pulp bleaching. PMID:19242691

  11. The effect of pulping concentration treatment on the properties of microcrystalline cellulose powder obtained from waste paper.

    PubMed

    Okwonna, Okumneme O

    2013-10-15

    Microcrystalline cellulose (MCC) powder was isolated from three grades of waste paper: book, Groundwood/Newsprint and paperboard, through the processes of pulping and hydrolysis. Pulping treatment on these grades of waste paper was done using varying concentrations of caustic soda. Effects of the concentration of the pulping medium on the thermal and kinetic properties were investigated. Also determined were the effects of this on the physico-chemical properties. The chemical structure was characterized using an infrared spectroscopy (FTIR). Results showed these properties to be affected by the concentration of the pulping medium. PMID:23987404

  12. Comprehensive genetic dissection of wood properties in a widely-grown tropical tree: Eucalyptus

    PubMed Central

    2011-01-01

    Background Eucalyptus is an important genus in industrial plantations throughout the world and is grown for use as timber, pulp, paper and charcoal. Several breeding programmes have been launched worldwide to concomitantly improve growth performance and wood properties (WPs). In this study, an interspecific cross between Eucalyptus urophylla and E. grandis was used to identify major genomic regions (Quantitative Trait Loci, QTL) controlling the variability of WPs. Results Linkage maps were generated for both parent species. A total of 117 QTLs were detected for a series of wood and end-use related traits, including chemical, technological, physical, mechanical and anatomical properties. The QTLs were mainly clustered into five linkage groups. In terms of distribution of QTL effects, our result agrees with the typical L-shape reported in most QTL studies, i.e. most WP QTLs had limited effects and only a few (13) had major effects (phenotypic variance explained > 15%). The co-locations of QTLs for different WPs as well as QTLs and candidate genes are discussed in terms of phenotypic correlations between traits, and of the function of the candidate genes. The major wood property QTL harbours a gene encoding a Cinnamoyl CoA reductase (CCR), a structural enzyme of the monolignol-specific biosynthesis pathway. Conclusions Given the number of traits analysed, this study provides a comprehensive understanding of the genetic architecture of wood properties in this Eucalyptus full-sib pedigree. At the dawn of Eucalyptus genome sequence, it will provide a framework to identify the nature of genes underlying these important quantitative traits. PMID:21651758

  13. IGCC power plant integrated to a Finnish pulp and paper mill: IEA bioenergy techno-economic analysis activity. Research notes

    SciTech Connect

    Koljonen, T.; Solantausta, Y.; Salo, K.; Horvath, A.

    1999-02-01

    This site-specific study describes the technical and economic feasibility of a biomass gasification combined cycle producing heat and power for a typical Finish pulp and paper mill. The aim is to replace an old bark boiler by an IGCC (Integrated Gasification Combined Cycle) to enhance the economy and environmental performance of the power plant. The IGCC feasibility study is conducted for a pulp and paper industrial plant because of its suitable infrastructure for IGCC and a large amount of wood waste available at the site. For comparison, the feasibility of an IGCC integrated to a pulp mill is also assessed. The operation and design of the IGCC concept is based on a 20 MW(e) gas turbine (MW151). The heat of gas turbine exhaust gas is utilized in a HRSG (Heat Recovery Steam Generator) of two pressure levels to generate steam for the pulp and paper mill and the steam turbine. The IGCC power plant operates in condensing mode. The techno-economic assessment of the biomass IGCC integrated to a pulp and paper mill or a pulp mill indicated that the IGCC will be competitive compared to the conventional bark boiler steam cycle. The IGCC integrated to a pulp and paper mill was slightly more economical than the IGCC pulp mill integration.

  14. Improved Wood Properties Through Genetic Manipulation: Engineering of Syringyl Lignin in Softwood Species Through Xylem-Specific Expression of Hardwood Syringyl Monolignol Pathway Genes

    SciTech Connect

    Chandrashekhar P. Joshi; Vincent L. Chiang

    2009-01-29

    Project Objective: Our long-term goal is to genetically engineer higher value raw materials with desirable wood properties to promote energy efficiency, international competitiveness, and environmental responsiveness of the U.S. forest products industry. The immediate goal of this project was to produce the first higher value softwood raw materials engineered with a wide range of syringyl lignin quantities. Summary: The most important wood property affecting directly the levels of energy, chemical and bleaching requirements for kraft pulp production is lignin. Softwoods contain almost exclusively chemically resistant guaiacyl (G) lignin, whereas hardwoods have more reactive or easily degradable lignins of the guaiacyl (G)-syringyl (S) type. It is also well established that the reactive S lignin component is the key factor that permits much lower effective alkali and temperature, shorter pulping time and less bleaching stages for processing hardwoods than for softwoods. Furthermore, our pulping kinetic study explicitly demonstrated that every increase in one unit of the lignin S/G ratio would roughly double the rate of lignin removal. These are clear evidence that softwoods genetically engineered with S lignin are keys to revolutionizing the energy efficiency and enhancing the environmental performance of this industry. Softwoods and hardwoods share the same genetic mechanisms for the biosynthesis of G lignin. However, in hardwoods, three additional genes branch out from the G-lignin pathway and become specifically engaged in regulating S lignin biosynthesis. In this research, we simultaneously transferred aspen S-specific genes into a model softwood, black spruce, to engineer S lignin.

  15. Method of treating contaminated HEPA filter media in pulp process

    DOEpatents

    Hu, Jian S.; Argyle, Mark D.; Demmer, Ricky L.; Mondok, Emilio P.

    2003-07-29

    A method for reducing contamination of HEPA filters with radioactive and/or hazardous materials is described. The method includes pre-processing of the filter for removing loose particles. Next, the filter medium is removed from the housing, and the housing is decontaminated. Finally, the filter medium is processed as pulp for removing contaminated particles by physical and/or chemical methods, including gravity, flotation, and dissolution of the particles. The decontaminated filter medium is then disposed of as non-RCRA waste; the particles are collected, stabilized, and disposed of according to well known methods of handling such materials; and the liquid medium in which the pulp was processed is recycled.

  16. Fluoropolymer use in the pulp and paper industry

    SciTech Connect

    Magdzinski, L.

    1999-11-01

    Fluoropolymers are ubiquitous in the pulp and paper industry. Fluoropolymer-lined pumps, valves, pipes, tanks, scrubbers, and towers are encountered frequently in the pulp mill. Chemically resistant fluoropolymer filter fabrics are used in bleach plant washers and flue gas scrubbers. In the recovery cycle, fluoropolymer coatings and fluoroelastomers are used as gaskets and expansion joints in accumulators and heat exchangers. Fluoropolymer-containing paper machine fabrics, roll covers, and greases provide corrosion-free, clean and smooth performance. The array of fluorinated materials for different applications is detailed. New corrosion and caustic resistant filter fabrics, surfacing veils, paints and ductwork are presented.

  17. Sawmill chemicals and carcinogenesis.

    PubMed Central

    Huff, J

    2001-01-01

    Workers in wood industries are exposed to variable medleys of chemicals, both natural and synthetic. Additional exposures include fungi, bacteria, bark and wood dusts, solvents, paints, and various other wood coatings. These individual and conglomerate exposures have been associated with diverse occupational illnesses and hazards, including cancers. In this commentary, I summarize both experimental and epidemiologic carcinogenesis results for several chemicals used in the wood industry, as well as for wood dust. Working in the wood industries entails excess risks of cancers, among other diseases and workplace injuries. A key to preventing occupationally and environmentally associated cancers, as in the wood industries, is avoiding exposures to chemicals and wood dusts and, in particular, chemicals known to cause cancer in animals or/and humans. PMID:11333179

  18. Composition, texture and methane potential of cellulosic residues from Lewis acids organosolv pulping of wheat straw.

    PubMed

    Constant, Sandra; Barakat, Abdellatif; Robitzer, Mike; Di Renzo, Francesco; Dumas, Claire; Quignard, Françoise

    2016-09-01

    Cellulosic pulps have been successfully isolated from wheat straw through a Lewis acids organosolv treatment. The use of Lewis acids with different hardness produced pulps with different delignification degrees. The cellulosic residue was characterised by chemical composition, X-ray diffraction, FT-IR spectroscopy, N2 physisorption, scanning electron microscopy and potential for anaerobic digestibility. Surface area and pore volume increased with the hardness of the Lewis acid, in correspondence with the decrease of the amount of lignin and hemicellulose in the pulp. The non linearity of the correlation between porosity and composition suggests that an agglomeration of cellulose fibrils occurs in the early stages of pulping. All organosolv pulps presented a significantly higher methane potential than the parent straw. A methane evolution of 295Ncm(3)/g OM was reached by a moderate improvement of the accessibility of the native straw. PMID:27295251

  19. The Fractionation of Loblolly Pine Woodchips Into Pulp For Making Paper Products

    SciTech Connect

    Kiran Kadam, PhD

    2006-11-30

    The overall goal of the project was to test the PureVision biomass fractionation technology for making pulp from loblolly pine. A specific goal was to produce a pulp product that is comparable to pulp produced from the kraft process, while reducing the environmental effects of the kraft process, known to be a highly pollutant process. The overall goal of the project was met by using the biomass fractionation concept for making pulp product. This proof-of-concept study, done with Southern pine pinchips as feedstock, evaluated NaOH concentration and residence time as variables in single-stage cocurrent pulping process. It can be concluded that 1% NaOH is adequate for effective delignification using the PureVision process; this is about 1/3 of that used in the kraft process. Also, the PureVision process does not use sulfur-based chemicals such as N2S and hence, is environmentally more benign.

  20. Canadian boreal pulp and paper feedstocks contain neuroactive substances that interact in vitro with GABA and dopaminergic systems in the brain.

    PubMed

    Waye, Andrew; Annal, Malar; Tang, Andrew; Picard, Gabriel; Harnois, Frédéric; Guerrero-Analco, José A; Saleem, Ammar; Hewitt, L Mark; Milestone, Craig B; MacLatchy, Deborah L; Trudeau, Vance L; Arnason, John T

    2014-01-15

    Pulp and paper wood feedstocks have been previously implicated as a source of chemicals with the ability to interact with or disrupt key neuroendocrine endpoints important in the control of reproduction. We tested nine Canadian conifers commonly used in pulp and paper production as well as 16 phytochemicals that have been observed in various pulp and paper mill effluent streams for their ability to interact in vitro with the enzymes monoamine oxidase (MAO), glutamic acid decarboxylase (GAD), and GABA-transaminase (GABA-T), and bind to the benzodiazepine-binding site of the GABA(A) receptor (GABA(A)-BZD). These neuroendocrine endpoints are also important targets for treatment of neurological disorders such as anxiety, epilepsy, or depression. MAO and GAD were inhibited by various conifer extracts of different polarities, including major feedstocks such as balsam fir, black spruce, and white spruce. MAO was selectively stimulated or inhibited by many of the tested phytochemicals, with inhibition observed by a group of phenylpropenes (e.g. isoeugenol and vanillin). Selective GAD inhibition was also observed, with all of the resin acids tested being inhibitory. GABA(A)-BZD ligand displacement was also observed. We compiled a table identifying which of these phytochemicals have been described in each of the species tested here. Given the diversity of conifer species and plant chemicals with these specific neuroactivities, it is reasonable to propose that MAO and GAD inhibition reported in effluents is phytochemical in origin. We propose disruption of these neuroendocrine endpoints as a possible mechanism of reproductive inhibition, and also identify an avenue for potential research and sourcing of conifer-derived neuroactive natural products. PMID:24041600

  1. Characterization of kraft pulp mill particulate emissions—A summary of existing measurements and observations

    NASA Astrophysics Data System (ADS)

    Pinkerton, John E.; Blosser, Russell O.

    Particulate matter emission sources at a kraft pulp mill include kraft recovery furnaces, lime kilns, smelt dissolving tanks and power boilers. Chemical and physical characteristics of these paniculate emissions are reviewed. Measurements of particle size distributions for these sources made with cascade impactors and microscopic counting techniques both before and after paniculate control devices such as multiple cyclones, wet scrubbers, and electrostatic precipitalors are discussed. In general, particles with equivalent diameters less than 3 jim comprise the bulk of the controlled paniculate emissions from all sources. Sodium sulfate is the dominant paniculate emission from kraft recovery furnaces, smelt dissolving tanks and lime kilns. Results from a field investigation of the relationship between human observations of near-stack plume opacity and measured in-stack paniculate concentrations and opacities are summarized. Trained cenified panels of observers were used in the investigation to estimate plume opacities from two kraft recovery furnaces, a combination wood/coal-fired boiler, and a combination wood/oil-fired boiler at four different pulp mill locations. Plume opacities were varied from near-zero to 45 % by adjustment of the paniculate control equipment operation. The effects of different background viewing conditions, observer positions, observer experience levels, and plume characteristics are enumerated. It is concluded that there can be substantial variations between measured in-stack opacities and human perceptions of near-stack plume opacities. The degree of agreement between the human judgements and measured in-stack opacities is significantly affected by the background viewing conditions. It is further shown that even with a panel of six or seven trained observers with similar visual acuity, there can be significant departures of individual opacity readings from the panel mean opacity. Although this investigation deals with questions of human

  2. Critical factors affecting laccase-mediated biobleaching of pulp in paper industry.

    PubMed

    Singh, Gursharan; Kaur, Kavleen; Puri, Sanjeev; Sharma, Prince

    2015-01-01

    Next to xylanases, laccases from fungi and alkali-tolerant bacteria are the most important biocatalysts that can be employed for eco-friendly biobleaching of hard and soft wood pulps in the paper industry. Laccases offer a potential alternative to conventional, environmental-polluting chlorine and chlorine-based bleaching and has no reductive effect on the final yield of pulp as compared to hemicellulases (xylanases and mannanases). In the last decade, reports on biobleaching with laccases are based on laboratory observations only. There are several critical challenges before this enzyme can be implemented for pulp bleaching at the industrial scale. This review discusses significant factors like redox potential, laccase mediator system (LMS)-synthetic or natural, pH, temperature, stability of enzyme, unwanted grafting reactions of laccase, and cost-intensive production at large scale which constitute a great hitch for the successful implementation of laccases at industrial level. PMID:25421562

  3. Wood's lamp illumination (image)

    MedlinePlus

    A Wood's lamp emits ultraviolet light and can be a diagnostic aid in determining if someone has a fungal ... is an infection on the area where the Wood's lamp is illuminating, the area will fluoresce. Normally ...

  4. Wood's lamp examination

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003386.htm Wood's lamp examination To use the sharing features on this page, please enable JavaScript. A Wood's lamp examination is a test that uses ultraviolet ( ...

  5. Wood's lamp examination

    MedlinePlus

    A Wood's lamp examination is a test that uses ultraviolet (UV) light to look at the skin closely. ... Gebhard RE. Wood's light examination. In: Pfenninger JL, Fowler GC, eds. ... Care . 3rd ed. Philadelphia, PA: Elsevier Mosby; 2010:chap ...

  6. Robert Wood Johnson Foundation

    MedlinePlus

    Robert Wood Johnson Foundation Search How We Work Our Focus Areas About RWJF Search Menu How We Work Grants and Grant ... more For Grantees and Grantseekers The Robert Wood Johnson Foundation supports a wide array of research and ...

  7. A decade of research on the environmental impacts of pulp and paper mill effluents in Canada: sources and characteristics of bioactive substances.

    PubMed

    Hewitt, L Mark; Parrott, Joanne L; McMaster, Mark E

    2006-01-01

    This article is a review of research efforts over the last decade on the sources and characteristics of substances in Canadian pulp mill effluents associated with two responses in fish: (1) induction of detoxification enzymes and (2) reproductive effects. The initial uncertainty regarding the role of chlorine bleaching and dioxins in these responses was resolved by the mid 1990s, when it was determined that effects were not correlated with effluent adsorbable organic halogen (AOX) levels and that releases of dioxins had decreased substantially. In the mid 1990s researchers were able to partially attribute enzyme activity induction in fish to wood components, while other studies showed individual wood extractives had the potential to affect fish reproduction. A lack of correlation between threshold reproductive responses and effluent concentrations indicated additional unidentified compounds and mechanisms were involved. In the late 1990s, source identification approaches in concert with the development of mechanistically linked in vitro and in vivo bioassays showed multiple compounds are affecting production and signaling of sex steroids in fish. These substances are bioavailable and accumulated rapidly, consistent with the body of evidence that has shown a sustained exposure is required to produce both elevated enzyme activity and depressions in sex steroid levels. The patterns of these substances in effluents and fish tissues are not correlated with production type or effluent treatment. Collectively, these findings show that bioactive substances originate from wood and are derived from lignin and/or terpenoids, they are liberated during pulp digestion, and in kraft mills they are present in black liquor and chemical recovery condensates. Additional bioactive substances are also present in bleachery effluents containing residual lignin. The lack of a definitive identification of the responsible compounds has prevented an evaluation of the effectiveness of

  8. Bio-refinery system of DME or CH4 production from black liquor gasification in pulp mills.

    PubMed

    Naqvi, M; Yan, J; Fröling, M

    2010-02-01

    There is great interest in developing black liquor gasification technology over recent years for efficient recovery of bio-based residues in chemical pulp mills. Two potential technologies of producing dimethyl ether (DME) and methane (CH(4)) as alternative fuels from black liquor gasification integrated with the pulp mill have been studied and compared in this paper. System performance is evaluated based on: (i) comparison with the reference pulp mill, (ii) fuel to product efficiency (FTPE) and (iii) biofuel production potential (BPP). The comparison with the reference mill shows that black liquor to biofuel route will add a highly significant new revenue stream to the pulp industry. The results indicate a large potential of DME and CH(4) production globally in terms of black liquor availability. BPP and FTPE of CH(4) production is higher than DME due to more optimized integration with the pulping process and elimination of evaporation unit in the pulp mill. PMID:19767203

  9. Dissolving pulp from jute stick.

    PubMed

    Matin, Mhafuza; Rahaman, M Mostafizur; Nayeem, Jannatun; Sarkar, Mamon; Jahan, M Sarwar

    2015-01-22

    Jute stick is woody portion of jute plant, which remain as leftover after extracting bast fibre. Presently, it is being used for fencing in the rural area. In this investigation, biorefinery concept was initiated in producing dissolving pulp from jute stick by pre-hydrolysis kraft process. At 170°C for 1h of pre-hydrolysis, 70% of hemicelluloses was dissolved with negligible loss of α-cellulose. At this condition, 75% of dissolved sugars in the pre-hydrolysis liquor were in the oligomeric form. The pre-hydrolysed jute stick was subsequently pulped by kraft process with the variation of active alkali. The pulp yield was 36.2% with kappa number 18.5 at the conditions of 16% active alkali for 2h of cooking at 170°C. Final pulp was produced with 92% α-cellulose and 89% brightness after D0EpD1EpD1 bleaching. The produced dissolving pulp can be used in rayon production. PMID:25439866

  10. Lignin analyzer based on pyrolysis-mass spectrometry of pulp in hydrogen or helium

    NASA Astrophysics Data System (ADS)

    Shakkottai, P.; Kwack, E. Y.; Lawson, D.

    1990-07-01

    The lignin content of wood, paper, pulp, or other materials containing lignin (such as filter paper soaked in black liquor) is readily determined by flash pyrolysis of the sample at approximately 550 °C in a reducing atmosphere of hydrogen or in an inert atmosphere of helium followed by a rapid analysis of the product gas by a mass spectrometer. The heated pyrolysis unit as fabricated, comprises a small platinum cup welded to an electrically heated stainless-steel ribbon with control units for programmed short duration (1.5 s, approximately) heating and for continuous flow of hydrogen or helium. The pyrolysis products enter an electron-ionization-mode mass spectrometer for spectral evaluation. Lignin content is obtained from certain ratios of integrated ion currents of many mass spectral lines, the ratios being linearly related to the Kappa number or Klason lignin. The Kappa number can be obtained from a few milligram sample in 3 min which is at least ten times faster than a Kappa number determination by the Standard Chemical Method. The present instrument can measure Kappa numbers in the whole range from 0 to 200 without any readjustments.

  11. Low effluent processing in the pulp and paper industry: Electrodialysis for continuous selective chloride removal

    SciTech Connect

    Pfromm, P.H.

    1997-12-01

    Pollution prevention is currently a major focus of the United States pulp and paper industry. Significant process changes are inevitable to implement low effluent processing. The kraft pulping process is prevalent for the production of wood pulp. About 50 million tons of wood pulp are produced annually in the United States alone using the kraft process. Water consumption is currently roughly between 30 and 200 m{sup 3} of water per ton of air dry bleached kraft pulp. In-process recycling of water is now being implemented by many mills to reduce the use of increasingly scarce water resources and to reduce the need for waste-water treatment. Mass balance considerations and industrial experience show that nonprocess elements, which are detrimental to the kraft process, such as chloride and potassium, will quickly build up once water use is significantly reduced. High concentrations of chloride and potassium can cause corrosion and lead to more frequent mill shutdowns due to fouling of heat exchanger surfaces in the kraft recovery furnace. Electrodialysis will monovalent selective anion and cation exchange membranes was explored here to selectively remove chlorine as sodium and potassium chloride from a feed stream with very high ionic strength. Experiments with model solutions and extended tests with the actual pulp mill materials were performed. Very good selectivities and current efficiencies were observed for chloride over sulfate. The outstanding performance of the process with actual mill materials containing organic and inorganic contamination shows great promise for rapid transfer to the pilot scale. This work is an example of the usefulness of membrane separations as a kidney in low effluent industrial processing.

  12. Skills Conversion Project: Chapter 6, Forest Operations and Wood Products. Final Report.

    ERIC Educational Resources Information Center

    National Society of Professional Engineers, Washington, DC.

    A study of the forest operations and wood products industries was conducted in Atlanta and Seattle by the National Society of Professional Engineers. Included among these industries are tree development, crop and land management, logging, material handling transportation, cutting, peeling, assembly, pulp and paper, mobile homes, construction,…

  13. Floodplains and wood

    NASA Astrophysics Data System (ADS)

    Wohl, Ellen

    2013-08-01

    Interactions between floodplains and wood date to the Carboniferous, when stable, multithread channel deposits appear with the evolution of tree-like plants. Foundational geologic texts, such as Lyell's, 1830Principles of Geology, describe floodplain-wood interactions, yet modern technical literature describes floodplain-wood interactions in detail for only a very limited range of environments. This likely reflects more than a century of deforestation, flow regulation, and channel engineering, including instream wood removal, which has resulted in severe wood depletion in most of the world's river networks. Instream wood affects floodplain form and process by altering flow resistance, conveyance and channel-floodplain connectivity, and influencing lateral and vertical accretion of floodplains. Instream wood reflects floodplain form and process as the floodplain influences wood recruitment via bank erosion and overbank flow, and wood transport and storage via floodplain effects on stage-discharge relations and flow resistance. Examining turnover times for instream wood at the reach scale in the context of a wood budget, floodplain characteristics influence fluvial transport and dynamics (wood recruitment), valley geometry (wood transport and storage), and hydraulics and river biota (wood decay and breakage). Accumulations of wood that vary from in situ jams and beaver dams in small channels to transport jams and log rafts in very large rivers can create stable, multithread channels and floodplain wetlands. Floodplain-wood interactions are best understood for a subset of small to medium-sized rivers in the temperate zone. We know little about these interactions on very large rivers, or on rivers in the tropical or boreal regions. This review suggests that most, if not all, channels and floodplains within forested catchments in the temperate zone historically had much greater wood loads and consequently much more obvious and important influences from wood than do

  14. Use of high-boiling point organic solvents for pulping oil palm empty fruit bunches.

    PubMed

    Rodríguez, Alejandro; Serrano, Luis; Moral, Ana; Pérez, Antonio; Jiménez, Luis

    2008-04-01

    Oil palm empty fruit bunches were used as an alternative raw material to obtain cellulosic pulp. Pulping was done by using high-boiling point organic solvents of decreased polluting power relative to classical (Kraft, sulphite) solvents but affording operation at similar pressure levels. The holocellulose, alpha-cellulose and lignin contents of oil palm empty fruit bunches (viz. 66.97%, 47.91% and 24.45%, respectively) are similar to those of some woody raw materials such as pine and eucalyptus, and various non-wood materials including olive tree prunings, wheat straw and sunflower stalks. Pulping tests were conducted by using ethyleneglycol, diethyleneglycol, ethanolamine and diethanolamine under two different sets of operating conditions, namely: (a) a 70% solvent concentration, 170 degrees C and 90 min; and (b) 80% solvent, 180 degrees C and 150 min. The solid/liquid ratio was six in both cases. The amine solvents were found to provide pulp with better properties than did the glycol solvents. Ethanolamine pulp exhibited the best viscosity and drainage index (viz. 636 mL/g and 17 degrees SR, respectively), and paper made from it the best breaking length (1709 m), stretch (1.95%), burst index (0.98 kN/g) and tear index (0.33 mNm(2)/g). Operating costs can be reduced by using milder conditions, which provide similar results. In any case, the amines are to be preferred to the glycols as solvents for this purpose. PMID:17507215

  15. Deinked pulp manufacturers make a midwest market

    SciTech Connect

    White, K.M. ); Meade, K.

    1993-09-01

    Deinked pulp manufacturers, a burgeoning trend in recycling, are opening up the market for office waste paper in the Midwest. Great Lakes Pulp and Fibre, Inc., (Menominee, Michigan), a new paper group formed by industry veterans, is planning a major deinked pulp mill in Michigan's Upper Peninsula that will recycle large amounts of office waste paper. The mill will have the capacity to process nearly 275,000 tons per year (tpy)-673 tpd-of mixed office paper into 182,000 tpd of sheet-dried, deinked pulp. That pulp would be sold to nearby fine paper manufacturers that want to have recycled content without adding their own deinking.

  16. Quantitative evaluation by attenuated total reflectance infrared (ATR-FTIR) spectroscopy of the chemical composition of decayed wood preserved in waterlogged conditions.

    PubMed

    Pizzo, Benedetto; Pecoraro, Elisa; Alves, Ana; Macchioni, Nicola; Rodrigues, José Carlos

    2015-01-01

    This paper reports on the assessment of lignin and holocellulose by means of ATR-FTIR analysis and multivariate PLS regression. The analysis was conducted on 59 samples coming from different excavations where wood had been preserved in waterlogged conditions. A range of results from different wood species (Alnus sp.p., Cupressus sempervirens, Larix decidua, Picea abies, Pinus sp.p., Quercus sp.p., Ulmus sp.p.), states of preservation, waterlogged environments, and burial times are presented. A calibration model was selected after comparing different reference data (samples extracted and not-extracted, and ash-rich and ash-free bases of calculation for the calibration values), and two different post-acquisition spectroscopic manipulations (both in terms of normalisation procedures and of spectral ranges used for the calibration). Results showed that the best models were different depending on which considered component (lignin or holocellulose) was measured and to which data set (softwood or hardwood) the samples belonged. It is shown that the predictive ability of the models is affected by high ash content (too contaminated samples had to be excluded in order to attain good results, because of excessive overlapping of bands related to the inorganic fraction) but not by the preliminary extraction of sample. Furthermore, the stability of best models is also demonstrated and a procedure of external validation carried out on an external set of samples confirmed the general validity of the identified models. PMID:25281067

  17. Control of the accumulation of non-process elements and organic compounds in pulp mills with bleach filtrate reuse. Milestones and progress, Quarter 9 (July 1--September 30, 1998)

    SciTech Connect

    Frederick, W.J.; Laver, M.L.; Rorrer, G.L.; Rudie, A.W.; Schmidl, W.

    1998-12-31

    The two approach changes that were discussed and recommended in the Quarter 8 (April 1--June 30, 1998) progress report have been implemented in the current project plan. The OLI software has been used to develop a preliminary process model for predicting the distribution of NPE`s in a two stage brownstock washer, and the OLI database has been upgraded to include improved chemical equilibrium data for metal-organic interactions. This exercise served as a tool to evaluate the data and methods developed in this study, and to demonstrate its utility to industry. The Weyerhaeuser-NAELS software has also been applied to predicting inorganic solubility behavior. Task C-1.2, Estimation of unavailable thermodynamic parameters (scheduled completion date: 12/97), has been combined with Task D-2.1, Evaluation of the estimation procedure (scheduled completion date: 3/99) with a new scheduled completion date of 8/99. A model for the adsorption of metal ions on wood pulp fibers will include transport effects as well as adsorption equilibrium, and will be combined with a brownstock washer model to evaluate its predictive capability in comparison with mill data, and to demonstrate the applicability of the results obtained in this project. Three tasks are behind schedule: Task A-2.3, Measurement of stability constants for wood organics with metal ions (scheduled completion date: 6/98), Task B-2.1, Measure metal adsorption isotherms on wood pulp (scheduled completion date: 9/97), and Task B-2.3, Measure metal ion adsorption kinetics for strongly adsorbing metal species (scheduled completion date: 3/98). The reasons and expected completion dates are discussed in the Performance Variances and Open Items section. All other tasks are either completed, on, or ahead of schedule.

  18. Towards the regulation of aerosol emissions by their potential health impact: Assessing adverse effects of aerosols from wood combustion and ship diesel engine emissions by combining comprehensive data on the chemical composition and their toxicological effects on human lung cells

    NASA Astrophysics Data System (ADS)

    Zimmermann, R.; Streibel, T.; Dittmar, G.; Kanashova, T.; Buters, J.; Öder, S.; Paur, H. R.; Dilger, M.; Weiss, C.; Harndorf, H.; Stengel, B.; Hirvonen, M. R.; Jokiniemi, J.; Hiller, K.; Sapcariu, S.; Sippula, O.; Orasche, J.; Müller, L.; Rheda, A.; Passig, J.; Radischat, C.; Czech, H.; Tiita, P.; Jalava, P.; Kasurinen, S.; Schwemer, T.; Yli-Prilä, P.; Tissari, J.; Lamberg, H.; Schnelle-Kreis, J.

    2014-12-01

    Ship engine emissions are important regarding lung and cardiovascular diseases in coastal regions worldwide. Bio mass burning is made responsible for adverse health effects in many cities and rural regions. The Virtual Helmholtz Institute-HICE (www.hice-vi.eu) addresses chemical & physical properties and health effects of anthropogenic combustion emissions. Typical lung cell responses to combustion aerosols include inflammation and apoptosis, but a molecular link with the specific chemical composition in particular of ship emissions has not been established. Through an air-liquid interface exposure system (ALI), we exposed human lung cells at-site to exhaust fumes from a ship engine running on common heavy fuel oil (HFO) and cleaner-burning diesel fuel (DF) as well as to emissions of wood combustion compliances. A special field deployable ALI-exposition system and a mobile S2-biological laboratory were developed for this study. Human alveolar basal epithelial cells (A549 etc.) are ALI-exposed to fresh, diluted (1:40-1:100) combustion aerosols and subsequently were toxicologically and molecular-biologically characterized. Advanced chemical analyses of the exhaust aerosols were combined with transcriptional, proteomic and metabolomic profiling to characterise the cellular responses. The HFO ship emissions contained high concentrations of toxic compounds (transition metals, organic toxicants) and particle masses. The cellular responses included inflammation and oxidative stress. Surprisingly, the DF ship emissions, which predominantly contain rather "pure" carbonaceous soot and much less known toxicants, induced significantly broader biological effects, affecting essential cellular pathways (e.g., mitochondrial function and intracellular transport). Therefore the use of distillate fuels for shipping (this is the current emission reduction strategy of the IMO) appears insufficient for diminishing health effects. The study suggests rather reducing the particle emissions

  19. Effects of dental trauma on the pulp.

    PubMed

    Love, R M

    1997-05-01

    Infection of the root canal system following dental trauma induces pulp and periapical disease and prevents healing of previously healthy pulp. A clinical goal in treating trauma is the maintenance of pulp vitality, and clinicians should be aware of factors that influence pulp healing. The learning objective of this article is to review the factors and techniques that influence pulp vitality and examine the influence pulp has on the healing of adjacent tissues. The potential routes for bacterial infection of the root canal system are discussed, with the clinical crown as the primary portal of entry. Uncomplicated and complicated crown fractures, as well as the crown-root and root fractures, are reviewed. Complications in pulp healing include canal obliteration, disturbed root development, apexogenesis, apexification, and the various forms of resorption. PMID:9550069

  20. Wood decay at sea

    NASA Astrophysics Data System (ADS)

    Charles, François; Coston-Guarini, Jennifer; Guarini, Jean-Marc; Fanfard, Sandrine

    2016-08-01

    The oceans and seas receive coarse woody debris since the Devonian, but the kinetics of wood degradation remains one of many unanswered questions about the fate of driftwood in the marine environment. A simple gravimetric experiment was carried out at a monitoring station located at the exit of a steep, forested Mediterranean watershed in the Eastern Pyrenees. The objective was to describe and quantify, with standardized logs (in shape, structure and constitution), natural degradation of wood in the sea. Results show that the mass decrease of wood logs over time can be described by a sigmoidal curve. The primary process of wood decay observed at the monitoring station was due to the arrival and installation of wood-boring species that consumed more than half of the total wood mass in six months. Surprisingly, in a region where there is little remaining wood marine infrastructure, "shipworms", i.e. xylophagous bivalves, are responsible for an important part of this wood decay. This suggests that these communities are maintained probably by a frequent supply of a large quantity of riparian wood entering the marine environment adjacent to the watershed. By exploring this direct link between terrestrial and marine ecosystems, our long term objective is to determine how these supplies of terrestrial organic carbon can sustain wood-based marine communities as it is observed in the Mediterranean Sea.

  1. Ultrasound-assisted extraction of arabinogalactan and dihydroquercetin simultaneously from Larix gmelinii as a pretreatment for pulping and papermaking.

    PubMed

    Ma, Chunhui; Yang, Lei; Li, Wei; Yue, Jinquan; Li, Jian; Zu, Yuangang

    2014-01-01

    An ultrasound-assisted extraction (UAE) method using ethanol was applied for extracting arabinogalactan (AG) and dihydroquercetin (DHQ) simultaneously from larch wood, as a pretreatment for pulping and papermaking. The extraction parameters were optimized by a Box-Behnken experimental design with the yields of AG and DHQ as the response values. Under optimum conditions (three extractions, each using 40% ethanol, for 50 min, 200 W ultrasound power and 1∶18 solid-liquid ratio), the yields of AG and DHQ were 183.4 and 36.76 mg/g, respectively. After UAE pretreated, the wood chips were used for Kraft pulping (KP) and high boiling solvent pulping (HBSP). The pulping yield after pretreatment was higher than that of untreated (the pulping yields of untreated HBSP and KP were 42.37% and 39.60%, and the pulping yields of HBSP and KP after UAE-pretreated were 44.23% and 41.50% respectively), as indicated by a lower kappa number (77.91 and 27.30 for untreated HBSP and KP; 77.01 and 26.83 for UAE-pretreated HBSP and KP). Furthermore, the characteristics of paper produced from pretreated wood chips were superior to those from the untreated chips: the basis weight was lower (85.67 and 82.48 g·cm(-2) for paper from untreated KP and HBSP; 79.94 and 80.25 g·cm(-2) for paper from UAE-pretreated KP and HBSP), and the tensile strengths, tearing strengths, bursting strengths, and folding strengths were higher than these of paper after UAE-pretreated, respectively. PMID:25460911

  2. Ultrasound-Assisted Extraction of Arabinogalactan and Dihydroquercetin Simultaneously from Larix gmelinii as a Pretreatment for Pulping and Papermaking

    PubMed Central

    Ma, Chunhui; Yang, Lei; Li, Wei; Yue, Jinquan; Li, Jian; Zu, Yuangang

    2014-01-01

    An ultrasound-assisted extraction (UAE) method using ethanol was applied for extracting arabinogalactan (AG) and dihydroquercetin (DHQ) simultaneously from larch wood, as a pretreatment for pulping and papermaking. The extraction parameters were optimized by a Box-Behnken experimental design with the yields of AG and DHQ as the response values. Under optimum conditions (three extractions, each using 40% ethanol, for 50 min, 200 W ultrasound power and 1∶18 solid-liquid ratio), the yields of AG and DHQ were 183.4 and 36.76 mg/g, respectively. After UAE pretreated, the wood chips were used for Kraft pulping (KP) and high boiling solvent pulping (HBSP). The pulping yield after pretreatment was higher than that of untreated (the pulping yields of untreated HBSP and KP were 42.37% and 39.60%, and the pulping yields of HBSP and KP after UAE-pretreated were 44.23% and 41.50% respectively), as indicated by a lower kappa number (77.91 and 27.30 for untreated HBSP and KP; 77.01 and 26.83 for UAE-pretreated HBSP and KP). Furthermore, the characteristics of paper produced from pretreated wood chips were superior to those from the untreated chips: the basis weight was lower (85.67 and 82.48 g·cm−2 for paper from untreated KP and HBSP; 79.94 and 80.25 g·cm−2 for paper from UAE-pretreated KP and HBSP), and the tensile strengths, tearing strengths, bursting strengths, and folding strengths were higher than these of paper after UAE-pretreated, respectively. PMID:25460911

  3. Bioluminescence inhibition assays for toxicity screening of wood extractives and biocides in paper mill process waters.

    PubMed

    Rigol, Anna; Latorre, Anna; Lacorte, Sílvia; Barceló, Damià

    2004-02-01

    The risk associated with wood extractives, biocides, and other additives in pulp and paper mill effluents was evaluated by performing a characterization of process waters and effluents in terms of toxicity and chemical analysis. The individual toxicity of 10 resin acids, two unsaturated fatty acids, and three biocides was estimated by measuring the bioluminescence inhibition with a ToxAlert 100 system. Median effective concentration values (EC50) of 4.3 to 17.9, 1.2 to 1.5, and 0.022 to 0.50 mg/L were obtained, respectively. Mixtures of these three families of compounds showed antagonistic effects. Chemical analysis of process waters was performed by liquid chromatography- and gas chromatography-mass spectrometry. Biocides such as 2-(thiocyanomethylthio)-benzotiazole (TCMTB) (EC50 = 0.022 mg/L) and 2,2-dibromo-3-nitrilpropionamide (DBNPA) (EC50 = 0.50 mg/L) were the most toxic compounds tested and were detected at concentrations of 16 and 59 microg/L, respectively, in a closed-circuit recycling paper mill. Process waters from kraft pulp mills, printing paper mills, and packing board paper mills showed the highest concentration of resin acids (up to 400 microg/L) and accounted for inhibition percentages up to 100%. Detergent degradation products such as nonylphenol (NP) and octylphenol (OP) and the plasticizer bisphenol A (BPA) were also detected in the waters at levels of 0.6 to 10.6, 0.3 to 1.4, and 0.7 to 187 microg/L, respectively. However, once these waters were biologically treated, the concentration of detected organic compounds diminished and the toxicity decreased in most cases to values of inhibition lower than 20%. PMID:14982380

  4. Effect of organosolv and soda pulping processes on the metals content of non-woody pulps.

    PubMed

    González, M; Cantón, L; Rodríguez, A; Labidi, J

    2008-09-01

    In this work the effect of different pulping processes (ethyleneglycol, diethyleneglycol, ethanolamine and soda) of tow abounded raw materials (empty fruit bunches - EFB and rice straw) on the ash, silicates and metals (Fe, Zn, Cu, Pb, Mn, Ni and Cd) content of the obtained pulps have been studied. Results showed that pulps obtained by diethyleneglycol pulping process presented lower metals content (756 microg/g and 501 microg/g for EFB and rice straw pulp, respectively) than soda pulps (984 microg/g and 889 microg/g). Ethanolamine pulps presented values of holocellulose (74% and 77% for EFB and rice straw pulp, respectively), alpha-cellulose (74% and 69%), kappa number (18.7 and 18.5) and viscosity (612 and 90 6ml/g) similar to those of soda pulp, and lower lignin contents (11% and 12%). PMID:18226892

  5. Pulp reaction to vital bleaching.

    PubMed

    Fugaro, Jessica O; Nordahl, Inger; Fugaro, Orlando J; Matis, Bruce A; Mjör, Ivar A

    2004-01-01

    This study evaluated the histological changes in dental pulp after nightguard vital bleaching with 10% carbamide peroxide gel. Fifteen patients between 12 and 26 years of age with caries-free first premolars scheduled for orthodontic extraction were treated with 10% Opalescence (Ultradent Products, Inc). Tooth #5 had four days of bleaching, tooth #12 was treated for two weeks, tooth #21 was bleached for two weeks followed by two weeks without treatment and tooth #28, serving as the control, was without treatment. All teeth were extracted at the same time. Immediately after extraction, 4 mm of the most apical portion of the root was sectioned off and each specimen was placed in a vial containing 10% neutral buffered formalin. The samples were prepared for histological evaluation at the Scandinavian Institute of Dental Materials (NIOM) and microscopically examined independently at both NIOM and Indiana University School of Dentistry (IUSD). Pulp reactions were semi-quantitatively graded as none, slight, moderate and severe. Slight pulpal changes were detected in 16 of the 45 bleached teeth. Neither moderate nor severe reactions were observed. The findings indicate that the slight histological changes sometimes observed after bleaching tend to resolve within two weeks post-treatment. Statistical differences existed only between the untreated control and the four-day (p=0.0109) and two-week (p=0.0045) treatment groups. The findings from this study demonstrated that nightguard vital bleaching procedures using 10% carbamide peroxide might cause initial mild, localized pulp reactions. However, the minor histological changes observed did not affect the overall health of the pulp tissue and were reversible within two weeks post-treatment. Therefore, two weeks of treatment with 10% carbamide peroxide used for nightguard vital bleaching is considered safe for dental pulp. PMID:15279473

  6. Pulp Regeneration: Current Approaches and Future Challenges

    PubMed Central

    Yang, Jingwen; Yuan, Guohua; Chen, Zhi

    2016-01-01

    Regenerative endodontics aims to replace inflamed/necrotic pulp tissues with regenerated pulp-like tissues to revitalize teeth and improve life quality. Pulp revascularization case reports, which showed successful clinical and radiographic outcomes, indicated the possible clinical application of pulp regeneration via cell homing strategy. From a clinical point of view, functional pulp-like tissues should be regenerated with the characterization of vascularization, re-innervation, and dentin deposition with a regulated rate similar to that of normal pulp. Efficient root canal disinfection and proper size of the apical foramen are the two requisite preconditions for pulp regeneration. Progress has been made on pulp regeneration via cell homing strategies. This review focused on the requisite preconditions and cell homing strategies for pulp regeneration. In addition to the traditionally used mechanical preparation and irrigation, antibiotics, irrigation assisted with EndoVac apical negative-pressure system, and ultrasonic and laser irradiation are now being used in root canal disinfection. In addition, pulp-like tissues could be formed with the apical foramen less than 1 mm, although more studies are needed to determine the appropriate size. Moreover, signaling molecules including stromal cell derived factor (SDF-1α), basic Fibroblast Growth Factor (bFGF), Platelet Derived Growth Factor (PDGF), stem cell factor (SCF), and Granulocyte Colony-Stimulating Factor (G-CSF) were used to achieve pulp-like tissue formation via a cell homing strategy. Studies on the cell sources of pulp regeneration might give some indications on the signaling molecular selection. The active recruitment of endogenous cells into root canals to regenerate pulp-like tissues is a novel concept that may offer an unprecedented opportunity for the near-term clinical translation of current biology-based therapies for dental pulp regeneration. PMID:27014076

  7. Effect of autohydrolysis on the wettability, absorbility and further alkali impregnation of poplar wood chips.

    PubMed

    Xu, Ningpan; Liu, Wei; Hou, Qingxi; Wang, Peiyun; Yao, Zhirong

    2016-09-01

    Autohydrolysis with different severity factors was performed on poplar wood chips prior to pulping, and the wettability, absorbility and the following impregnation of NaOH solution for the poplar wood chips were then investigated. The results showed that after autohydrolysis pretreatment the porosity, shrinkage and fiber saturation point (FSP) of the poplar wood chips were increased, while the surface contact angle decreased as the severity factor was increased. The autohydrolyzed chips absorbed more NaOH in impregnation that resulted in a low NaOH concentration in the bulk impregnation liquor (i.e., the impregnation liquor outside wood chips), while the concentration in the entrapped liquor (i.e., the impregnation liquor inside wood chips) was increased. Autohydrolysis substantially improved the effectiveness of alkali impregnation. PMID:27259186

  8. Protection of Wood from Microorganisms by Laccase-Catalyzed Iodination

    PubMed Central

    Engel, J.; Thöny-Meyer, L.; Schwarze, F. W. M. R.; Ihssen, J.

    2012-01-01

    In the present work, Norway spruce wood (Picea abies L.) was reacted with a commercial Trametes versicolor laccase in the presence of potassium iodide salt or the phenolic compounds thymol and isoeugenol to impart an antimicrobial property to the wood surface. In order to assess the efficacy of the wood treatment, a leaching of the iodinated and polymerized wood and two biotests including bacteria, a yeast, blue stain fungi, and wood decay fungi were performed. After laccase-catalyzed oxidation of the phenols, the antimicrobial effect was significantly reduced. In contrast, the enzymatic oxidation of iodide (I−) to iodine (I2) in the presence of wood led to an enhanced resistance of the wood surface against all microorganisms, even after exposure to leaching. The efficiency of the enzymatic wood iodination was comparable to that of a chemical wood preservative, VP 7/260a. The modification of the lignocellulose by the laccase-catalyzed iodination was assessed by the Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) technique. The intensities of the selected lignin-associated bands and carbohydrate reference bands were analyzed, and the results indicated a structural change in the lignin matrix. The results suggest that the laccase-catalyzed iodination of the wood surface presents an efficient and ecofriendly method for wood protection. PMID:22865075

  9. Protection of wood from microorganisms by laccase-catalyzed iodination.

    PubMed

    Schubert, M; Engel, J; Thöny-Meyer, L; Schwarze, F W M R; Ihssen, J

    2012-10-01

    In the present work, Norway spruce wood (Picea abies L.) was reacted with a commercial Trametes versicolor laccase in the presence of potassium iodide salt or the phenolic compounds thymol and isoeugenol to impart an antimicrobial property to the wood surface. In order to assess the efficacy of the wood treatment, a leaching of the iodinated and polymerized wood and two biotests including bacteria, a yeast, blue stain fungi, and wood decay fungi were performed. After laccase-catalyzed oxidation of the phenols, the antimicrobial effect was significantly reduced. In contrast, the enzymatic oxidation of iodide (I(-)) to iodine (I(2)) in the presence of wood led to an enhanced resistance of the wood surface against all microorganisms, even after exposure to leaching. The efficiency of the enzymatic wood iodination was comparable to that of a chemical wood preservative, VP 7/260a. The modification of the lignocellulose by the laccase-catalyzed iodination was assessed by the Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) technique. The intensities of the selected lignin-associated bands and carbohydrate reference bands were analyzed, and the results indicated a structural change in the lignin matrix. The results suggest that the laccase-catalyzed iodination of the wood surface presents an efficient and ecofriendly method for wood protection. PMID:22865075

  10. Floods and Fluvial Wood

    NASA Astrophysics Data System (ADS)

    Comiti, F.

    2014-12-01

    Several studies have recently addressed the complex interactions existing at various spatial scales among riparian vegetation, channel morphology and wood storage. The majority of these investigations has been carried out in relatively natural river systems, focusing mostly on the long-term vegetation-morphology dynamics under "equilibrium" conditions. Little is still known about the role of flood events - of different frequency/magnitude - on several aspects of such dynamics, e.g. entrainment conditions of in-channel wood, erosion rates of vegetation from channel margins and from islands, transport distances of wood elements of different size along the channel network. Even less understood is how the river's evolutionary trajectory may affect these processes, and thus the degree to which conceptual models derivable from near-natural systems could be applicable to human-disturbed channels. Indeed, the different human pressures - present on most river basins worldwide - have greatly impaired the morphological and ecological functions of fluvial wood, and the attempts to "restore" in-channel wood storage are currently carried out without a sufficient understanding of wood transport processes occurring during floods. On the other hand, the capability to correctly predict the magnitude of large wood transport during large floods is now seen as crucial - especially in mountain basins - for flood hazard mapping, as is the identification of the potential wood sources (e.g. landslides, floodplains, islands) for the implementation of sound and effective hazard mitigation measures. The presentation will first summarize the current knowledge on fluvial wood dynamics and modelling at different spatial and temporal scales, with a particular focus on mountain rivers. The effects of floods of different characteristics on vegetation erosion and wood transport will be then addressed presenting some study cases from rivers in the European Alps and in the Italian Apennines featuring

  11. Urban Wood Waste Resource Assessment

    SciTech Connect

    Wiltsee, G.

    1998-11-20

    This study collected and analyzed data on urban wood waste resources in 30 randomly selected metropolitan areas in the United States. Three major categories wood wastes disposed with, or recovered from, the municipal solid waste stream; industrial wood wastes such as wood scraps and sawdust from pallet recycling, woodworking shops, and lumberyards; and wood in construction/demolition and land clearing debris.

  12. Urban Wood Waste Resource Assessment

    SciTech Connect

    G. Wiltsee.

    1999-01-21

    This study collected and analyzed data on urban wood waste resources in 30 randomly selected metropolitan areas in the United States. Three major categories (wood wastes disposed with, or recovered from, the municipal solid waste stream; industrial wood wastes such as wood scraps and sawdust from pallet recycling, woodworking shops, and lumberyards; and wood in construction/demolition and land clearing debris.

  13. New Approaches in Vital Pulp Therapy in Permanent Teeth

    PubMed Central

    Ghoddusi, Jamileh; Forghani, Maryam; Parisay, Iman

    2014-01-01

    Vitality of dental pulp is essential for long-term tooth survival. The aim of vital pulp therapy is to maintain healthy pulp tissue by eliminating bacteria from the dentin-pulp complex. There are several different treatment options for vital pulp therapy in extensively decayed or traumatized teeth. Pulp capping or pulpotomy procedures rely upon an accurate assessment of the pulp status, and careful management of the remaining pulp tissue. The purpose of this review is to provide an overview of new approaches in vital pulp therapy in permanent teeth. PMID:24396371

  14. Cary Woods Elementary School.

    ERIC Educational Resources Information Center

    Havens, Glenda

    1994-01-01

    Describes the school reading program at Cary Woods Elementary School (in Auburn, Alabama), one of several school reading programs designated by the International Reading Association as exemplary. (SR)

  15. Wood pellet production

    SciTech Connect

    Moore, J.W.

    1983-08-01

    Southern Energy Limited's wood pellet refinery, Bristol, Florida, produces wood pellets for fuel from scrap wood from a nearby sawmill and other hog fuel delivered to the plant from nearby forest lands. The refinery will provide 50,000 tons of pellets per year to the Florida State Hospital at Chattahoochee to fire recently converted boilers in the central power plant. The pellets are densified wood, having a moisture content of about 10% and a heating value of 8000 Btu/lb. They are 0.5 inches in diameter and 2 to 3 inches in length.

  16. Biomass - chemicals

    SciTech Connect

    Kovaly, K.A.

    1982-08-01

    A host of industrial chemicals, specialty items, solvents, plastics, elastomers, fibers and films can be produced from agricultural crops, wood, paper mill wastes, food processing wastes, municipal waste and sewage. Existing chemical processes based on readily renewable plant materials are reviewed. These include ethanol and acetone-butanol fermentations, oilseed chemicals, furfural and cellulosics. (Refs. 16).

  17. Use of xylanase in the TCF bleaching of eucalyptus kraft pulp

    SciTech Connect

    Roncero, B.; Vidal, T.; Torres, A.L.; Colom, J.F.

    1996-10-01

    Environmental pressures are forcing the pulp and paper industry to develop new technologies that reduce or eliminate the presence of various contaminants in bleaching plant effluents. Oxygen delignification techniques, replacement of elemental chlorine with chlorine dioxide, ozone, hydrogen peroxide and new agents as well as the use of xylanase enzymes for biobleaching, reduce o eliminate the production of chlorinated organic substances. This paper compares the sequence XOZP with OZP in the bleaching of Eucalyptus globulus kraft pulps. It has been studied the influence of enzymatic treatment on the consumption of bleaching agents: ozone and hydrogen peroxide. Chemical, physical, optical and refining properties of pulps, as well as COD and colour of effluent are also studied. The xylanase treatment is positive and it is possible to manufacture fully bleached pulps at high brightness and viscosity without using chlorine compounds at a low ozone and hydrogen peroxide consumption.

  18. Anaerobic treatment of pulp and paper mill effluents--status quo and new developments.

    PubMed

    Habets, Leo; Driessen, Willie

    2007-01-01

    Since the early 1980s, anaerobic treatment of industrial effluents has found widespread application in the pulp and paper industry. Over 200 installations are treating a large variety of different pulp and paper mill effluents. Amongst various anaerobic systems the UASB and IC are the most applied anaerobic reactor systems. Anaerobic treatment is well feasible for effluents originated from recycle paper mills, mechanical pulping (peroxide bleached), semi-chemical pulping and sulphite and kraft evaporator condensates. The advantages of anaerobic pre-treatment are (1) net production of renewable energy (biogas), (2) minimized bio-solids production, (3) minimal footprint and (4) reduced emission of greenhouse gases. Via in-line application of anaerobic treatment in closed circuits (paper kidney technology) further savings on cost of fresh water intake and effluent discharge levies are generated. PMID:17486855

  19. [Functional morphology of pulp tissue].

    PubMed

    Heine, H; Schaeg, G; Türk, R

    1989-01-01

    As compared with mesenchyme no genuine defense cells are developed in the tissue of the dental pulp and the nervous tissue. This is a further hint for the common development from ectoderm. The three dimensional meshwork of pulpa fibroblasts ("mesectoderm") is structured by elongated cell processes connected with each other by a variety of special cell junctions ("electronic cell coupling"). Metabolites from the microcirculation and neuropeptides from vegetative axons influence the activity of fibroblasts synthetizing groundsubstance. The meshwork of the groundsubstance has exclusion effects concerning molecules with a distinct molecular weight and charge. Thus a primitive defense system is established. With this the role of a newly described cell type of the dental pulp, the "lymphocytic pericyte" is discussed. Because of the poor capacity of the pulpa tissue for immunological reactions pathologically disorders may easily become chronically spreading their antigenic components throughout the body. PMID:2800671

  20. CONTROL OF WOOD STOVE EMISSIONS USING IMPROVED SECONDARY COMBUSTION

    EPA Science Inventory

    The report gives results of the operation of two wood stoves in the laboratory with simultaneous on-line chemical analysis of the gases entering the secondary combustion zone and those leaving the stove. (NOTE: Self-initiating secondary combustion in wood stoves is encouraged by ...

  1. How James Wood Works

    ERIC Educational Resources Information Center

    Goldstein, Evan R., Comp.

    2008-01-01

    Reading through news-media clippings about James Wood, one might reasonably conclude that "pre-eminent critic" is his official job title. In fact, Wood is a staff writer for "The New Yorker" and a professor of the practice of literary criticism at Harvard University. But at a time when there is much hand-wringing about the death of the…

  2. Organic compounds in biomass smoke from residential wood combustion: Emissions characterization at a continental scale

    NASA Astrophysics Data System (ADS)

    Fine, Philip M.; Cass, Glen R.; Simoneit, Bernd R. T.

    2002-11-01

    Wood smoke in the atmosphere often accounts for 20-30% of the ambient fine-particle concentrations. In communities where wood is burned for home heating, wood smoke can at times contribute the majority of the atmospheric fine-particle burden. Chemical mass balance receptor models that use organic compounds as tracers can be used to determine the contributions of different emission sources, including wood smoke, to atmospheric fine-particle samples. In order for organic chemical tracer techniques to be applied to communities across the United States, differences in wood smoke composition that arise from differences in the type of wood burned in various regions must be understood. A continental-scale accounting of particulate organic compound emissions from residential wood combustion has been constructed which helps to quantify the regional differences in wood smoke composition that exist between different parts of the United States. Data from a series of source tests conducted on 22 North American wood species have been used to assemble a national inventory of emissions for more than 250 individual organic compounds that are released from wood combustion in fireplaces and wood stoves in the United States. The emission rates of important wood smoke markers, such as levoglucosan, certain substituted syringols and guaiacols, and phytosterols vary greatly with wood type and combustor type. These differences at the level of individual wood type and combustion conditions translate into regional differences in the aggregate composition of ambient wood smoke. By weighting the source test results in proportion to the availability of firewood from specific tree species and the quantities of wood burned in each locale, it is possible to investigate systematic differences that exist between wood smokes from different regions of North America. The relative abundance of 10 major wood smoke components averaged over the emissions inventory in different regions of the United States

  3. [The influence of oil heat treatment on wood decay resistance by Fourier infrared spectrum analysis].

    PubMed

    Wang, Ya-Mei; Ma, Shu-Ling; Feng, Li-Qun

    2014-03-01

    Wood preservative treatment can improve defects of plantation wood such as easy to corrupt and moth eaten. Among them heat-treatment is not only environmental and no pollution, also can improve the corrosion resistance and dimension stability of wood. In this test Poplar and Mongolian Seoteh Pine was treated by soybean oil as heat-conducting medium, and the heat treatment wood was studied for indoor decay resistance; wood chemical components before and after treatment, the effect of heat treatment on wood decay resistance performance and main mechanism of action were analysed by Fourier infrared spectrometric. Results showed that the mass loss rate of poplar fell from 19.37% to 5% and Mongolian Seoteh Pine's fell from 8.23% to 3.15%, so oil heat treatment can effectively improve the decay resistance. Infrared spectrum analysis shows that the heat treatment made wood's hydrophilic groups such as hydroxyl groups in largely reduced, absorbing capacity decreased and the moisture of wood rotting fungi necessary was reduced; during the heat treatment wood chemical components such as cellulose, hemicellu lose were degraded, and the nutrient source of wood rotting fungi growth necessary was reduced. Wood decay fungi can grow in the wood to discredit wood is because of that wood can provide better living conditions for wood decay fungi, such as nutrients, water, oxygen, and so on. The cellulose and hemicellulose in wood is the main nutrition source of wood decay fungi. So the oil heat-treatment can reduce the cellulose, hemicellulose nutrition source of wood decay fungi so as to improve the decay resistance of wood. PMID:25208386

  4. Dipolar-dephasing 13C NMR studies of decomposed wood and coalified xylem tissue: Evidence for chemical structural changes associated with defunctionalization of lignin structural units during coalification

    USGS Publications Warehouse

    Hatcher, P.G.

    1988-01-01

    A series of decomposed and coalified gymnosperm woods was examined by conventional solid-state 13C nuclear magnetic resonance (NMR) and by dipolar-dephasing NMR techniques. The results of these NMR studies for a histologically related series of samples provide clues as to the nature of codification reactions that lead to the defunctionalization of lignin-derived aromatic structures. These reactions sequentially involve the following: (1) loss of methoxyl carbons from guaiacyl structural units with replacement by hydroxyls and increased condensation; (2) loss of hydroxyls or aryl ethers with replacement by hydrogen as rank increases from lignin to high-volatile bituminous coal; (3) loss of alkyl groups with continued replacement by hydrogen. The dipolar-dephasing data show that the early stages of coalification in samples examined (lignin to lignite) involve a decreasing degree of protonation on aromatic rings and suggest that condensation is significant during coalification at this early stage. An increasing degree of protonation on aromatic rings is observed as the rank of the sample increases from lignite to anthracite.

  5. Integration of pulp and paper technology with bioethanol production

    PubMed Central

    2013-01-01

    Background Despite decades of work and billions of dollars of investments in laboratory and pilot plant projects, commercial production of cellulosic ethanol is only now beginning to emerge. Because of: (1)high technical risk coupled with; (2) high capital investment cost relative to ethanol product value, investors have not been able to justify moving forward with large scale projects on woody biomass. Results Both issues have been addressed by targeting pulp and paper industry processes for application in bioethanol production, in Greenfield, Repurpose and Co-Location scenarios. Processes commercially proven in hundreds of mills for many decades have been tailored to the recalcitrance of the biomass available. Economically feasible cellulosic bioethanol can be produced in Greenfield application with hardwoods, but not softwoods, using kraft mill equipment. Both types of wood species can profitably produce ethanol when kraft mill or newsprint assets are Repurposed to a biorefinery. A third situation which can generate high financial returns is where excess kraft pulp is available at a mill which has no excess drying capacity. Each scenario is supported by laboratory simulation, engineering and financial analysis. While pretreatment is critical to providing access of the biomass to enzymes, capital investment per unit of ethanol produced can be attractive, even if ethanol yield is modest. Conclusions Three guiding principles result in attractive economics: (1) re-use existing assets to the maximum extent; (2) keep the process as simple as possible; (3) match the recalcitrance of the biomass with the severity of the pretreatment. PMID:23356540

  6. UV resistance and dimensional stability of wood modified with isopropenyl acetate.

    PubMed

    Nagarajappa, Giridhar B; Pandey, Krishna K

    2016-02-01

    Chemical modification of Rubberwood (Hevea brasiliensis Müll.Arg) with isopropenyl acetate (IPA) in the presence of anhydrous aluminum chloride as a catalyst has been carried out under solvent free conditions. The level of modification was estimated by determining the weight percent gain and modified wood was characterized by FTIR-ATR and CP/MAS (13)C NMR spectroscopy. The effect of catalyst concentration on WPG was studied. UV resistance, moisture adsorption and dimensional stability of modified wood were evaluated. UV resistance of modified wood was evaluated by exposing unmodified and modified wood to UV irradiation in a QUV accelerated weathering tester. Unmodified wood showed rapid color changes and degradation of lignin upon exposure to UV light. Chemical modification of wood polymers with IPA was effective in reducing light induced color changes (photo-yellowing) at wood surfaces. In contrast to unmodified wood, modified wood exhibited bleaching. FTIR analysis of modified wood exposed to UV light indicated stabilization of wood polymers against UV degradation. Modified wood showed good dimensional stability and hydrophobicity. Thermogravimetric analysis showed that modification with IPA improved thermal stability of wood. Improved dimensional stability and UV resistance of modified wood indicates IPA as a promising reagent since there is no acid byproduct of reaction as observed in case of other esterification reactions. PMID:26722999

  7. Unrefined wood hydrolysates are viable reactants for the reproducible synthesis of highly swellable hydrogels.

    PubMed

    Maleki, Laleh; Edlund, Ulrica; Albertsson, Ann-Christine

    2014-08-01

    A value-adding robust and sequential synthetic pathway was elaborated to produce hydrogel structures with ionic character from crude acetylated galactoglucomannan-rich wood hydrolysate (WH). The WH was first-step liquor originating from a sulphite cracking pulp process for dissolving pulp. The synthetically modified WH fractions were verified at each step by NMR and FTIR, and the hydrogels were characterized with respect to their swelling and mechanical properties. Altering the crosslinking chemistry and the content of ionic moieties resulted in hydrogels with various swelling ratios and mechanical properties. Renewable hydrogel formulations with swelling ratios as high as Qeq=270 were achieved. PMID:24751275

  8. SITE CHARACTERIZATION AND THERMAL REMEDIATION TREATABILITY STUDIES FOR TWO WOOD TREATER SITES

    EPA Science Inventory

    Assessment of the applicability of thermal remediation at two wood treater sites is ongoing. The two wood treaters had been in operation for 50 to 80 years, and a variety of wood treating chemicals had been employed, including creosote, pentachlorophenol, and various metal prepa...

  9. X-RAY DENSITOMETRY OF NORWAY SPRUCE SUBFOSSIL WOOD FROM THE AUSTRIAN ALPS

    PubMed Central

    KŁUSEK, MARZENA; GRABNER, MICHAEL

    2016-01-01

    The processing of subfossil wood poses some difficulties in densitometric research. Problems arise because of the physio-chemical changes of wood occurring in the sedimentation environment. Subfossil wood modification can result from the uptake of mineral and organic substances into the wood tissue. It can also occur as the effect of microbiological degradation of wood. The goal of this study was to identify the appropriate method of subfossil wood preparation for the densitometric research. For this purpose the wood of Norway spruce from Lake Schwarzensee was subjected to extraction in deionized water, acetone and diluted acetic acid. The application of acetic acid did not significantly influence the density of the wood and acetone seemed to be too aggressive. The best result was obtained by rinsing the samples in cold de-ionized water. This extraction procedure allowed removal of unwanted water-soluble, organic and inorganic compounds from wood and simultaneously did not lead to the degradation of subfossil samples. PMID:27158247

  10. How to decrease the hydrophilicity of wood flour to process efficient composite materials

    NASA Astrophysics Data System (ADS)

    Pouzet, M.; Gautier, D.; Charlet, K.; Dubois, M.; Béakou, A.

    2015-10-01

    Dynamic fluorination and static fluorination were applied to wood flour to decrease its hydrophilic character, aiming at processing wood-polymer composites with good properties. Fourier-Transform infrared spectra and 19F solid state NMR (Nuclear Magnetic Resonance) results proved the successful covalent bonding of fluorine atoms onto the wood's chemical structure. It revealed that static fluorination brings about a less damaged and less hydrophilic fluorinated wood than with dynamic fluorination. Composites manufactured from this fluorinated wood presented a hydrophobic character directly related to the hydrophicity of these wood reinforcements. A composite made with fluorinated wood and polyester exhibited a higher hydrophobicity than the neat polyester and than the composite made with non-treated wood. Moreover, the further fluorination of a composite made of fluorinated wood led to a contact angle comparable to that of some metals (steel, gold) due to the etching of the composite surface during fluorination.

  11. Chemical and functional characterization of seed, pulp and skin powder from chilto (Solanum betaceum), an Argentine native fruit. Phenolic fractions affect key enzymes involved in metabolic syndrome and oxidative stress.

    PubMed

    Orqueda, María Eugenia; Rivas, Marisa; Zampini, Iris Catiana; Alberto, María Rosa; Torres, Sebastian; Cuello, Soledad; Sayago, Jorge; Thomas-Valdes, Samanta; Jiménez-Aspee, Felipe; Schmeda-Hirschmann, Guillermo; Isla, María Inés

    2017-02-01

    The aim of this work was to assess the nutritional and functional components of powder obtained by lyophilization of whole fruits, seeds, pulp and skin from chilto (Solanum betaceum Cav) cultivated in the ecoregion of Yungas, Argentina. The powders have low carbohydrate and sodium content and are a source of vitamin C, carotenoid, phenolics, potassium and fiber. The HPLC-ESI-MS/MS analysis of the fractions enriched in phenolics allowed the identification of 12 caffeic acid derivatives and related phenolics, 10 rosmarinic acid derivatives and 7 flavonoids. The polyphenols enriched extracts before and after simulated gastroduodenal digestion inhibited enzymes associated with metabolic syndrome, including α-glucosidase, amylase and lipase and exhibited antioxidant activity by different mechanisms. None of the analyzed fruit powders showed acute toxicity or genotoxicity. The powders from the three parts of S. betaceum fruit may be a potential functional food and the polyphenol enriched extract of seed and skin may have nutraceutical properties. PMID:27596394

  12. Fate of Residual Lignin during Delignification of Kraft Pulp by Trametes versicolor

    PubMed Central

    Reid, Ian D.

    1998-01-01

    The fungus Trametes versicolor can delignify and brighten kraft pulps. To better understand the mechanism of this biological bleaching and the by-products formed, I traced the transformation of pulp lignin during treatment with the fungus. Hardwood and softwood kraft pulps containing 14C-labelled residual lignin were prepared by laboratory pulping of lignin-labelled aspen and spruce wood and then incubated with T. versicolor. After initially polymerizing the lignin, the fungus depolymerized it to alkali-extractable forms and then to soluble forms. Most of the labelled carbon accumulated in the water-soluble pool. The extractable and soluble products were oligomeric; single-ring aromatic products were not detected. The mineralization of the lignin carbon to CO2 varied between experiments, up to 22% in the most vigorous cultures. The activities of the known enzymes laccase and manganese peroxidase did not account for all of the lignin degradation that took place in the T. versicolor cultures. This fungus may produce additional enzymes that could be useful in enzyme bleaching systems. PMID:9603823

  13. BIOREMEDIATION TREATABILITY STUDIES OF CONTAMINATED SOILS AT WOOD PRESERVING SITES

    EPA Science Inventory

    Bioremediationis used frequently at sites contaminated with organic hazardous chemical where releases from processing vessels and the mismanagement of reagents and generated waste have contributed to significant impairment of the environment. At wood treater sites, process reagen...

  14. Cord Wood Testing in a Non-Catalytic Wood Stove

    SciTech Connect

    Butcher, T.; Trojanowski, R.; Wei, G.

    2014-06-30

    EPA Method 28 and the current wood stove regulations have been in-place since 1988. Recently, EPA proposed an update to the existing NSPS for wood stove regulations which includes a plan to transition from the current crib wood fuel to cord wood fuel for certification testing. Cord wood is seen as generally more representative of field conditions while the crib wood is seen as more repeatable. In any change of certification test fuel, there are questions about the impact on measured results and the correlation between tests with the two different fuels. The purpose of the work reported here is to provide data on the performance of a noncatalytic stove with cord wood. The stove selected has previously been certified with crib wood which provides a basis for comparison with cord wood. Overall, particulate emissions were found to be considerably higher with cord wood.

  15. Modification in the properties of paper by using cellulase-free xylanase produced from alkalophilic Cellulosimicrobium cellulans CKMX1 in biobleaching of wheat straw pulp.

    PubMed

    Walia, Abhishek; Mehta, Preeti; Guleria, Shiwani; Shirkot, Chand Karan

    2015-09-01

    Alkalophilic Cellulosimicrobium cellulans CKMX1 isolated from mushroom compost is an actinomycete that produces industrially important and environmentally safer thermostable cellulase-free xylanase, which is used in the pulp and paper industry as an alternative to the use of toxic chlorinated compounds. Strain CKMX1 was previously characterized by metabolic fingerprinting, whole-cell fatty acids methyl ester analysis, and 16S rDNA and was found to be C. cellulans CKMX1. Crude enzyme (1027.65 U/g DBP) produced by C. cellulans CKMX1, having pH and temperature optima of 8.0 and 60 °C, respectively, in solid state fermentation of apple pomace, was used in the production of bleached wheat straw pulp. Pretreatment with xylanase at a dose of 5 U/g after pulping decreased pulp kappa points by 1.4 as compared with the control. Prebleaching with a xylanase dose of 5 U/g pulp reduced the chlorine charge by 12.5%, increased the final brightness points by approximately 1.42% ISO, and improved the pulp strength properties. Xylanase could be substituted for alkali extraction in C-Ep-D sequence and used for treating chemically bleached pulp, resulting in bleached pulp with higher strength properties. Modification of bleached pulp with 5 U of enzyme/g increased pulp whiteness and breaking length by 1.03% and 60 m, respectively; decreased tear factor of pulp by 7.29%; increased bulk weight by 3.99%, as compared with the original pulp. Reducing sugars and UV-absorbing lignin-derived compound values were considerably higher in xylanase-treated samples. Cellulosimicrobium cellulans CKMX1 has a potential application in the pulp and paper industries. PMID:26220821

  16. Backward-mode photoacoustic transducer for sensing optical scattering and ultrasonic attenuation: determining fraction consistencies in pulp suspensions

    NASA Astrophysics Data System (ADS)

    Zhao, Zuomin; Törmänen, Matti; Myllylä, Risto

    2010-02-01

    An innovative backward-mode photoacoustic transducer was developed, consisting of an optical fibre, a composite absorber, piezoelectric film and high impedance preamplifier. By receiving scattering light from a turbid suspension, the transducer produces a photoacoustic source in it. This source emits two photoacoustic waves travelling in opposite directions. The waves' amplitudes relate to the optical scattering properties of the suspension, and the echo of a wave returning from the suspension carries information of acoustic attenuation. By assessing the optical scattering and acoustic attenuation, fraction consistencies in a two-fractional suspension can be determined if one fraction dominantly scatters light and the other mainly attenuates ultrasound. This technique is used in this paper to investigate paper pulp suspensions. Pulp consists of wood celluloses and wood fines (or extra-added fillers in some cases), where cellulose lengths range from a few sub-millimetres to millimetres and fines/filler sizes are a few tens of micrometres or smaller. Due to their different size and shape, celluloses and fines (or fillers) have different optical scattering and acoustic attenuation properties. Experimental results showed that the transducer can measure pulp consistency with good linearity at least in the range from 0.5% to 3%, and that it can distinguish pulp cellulose from fines or fillers (TiO2 particles). Needless to say, this technique is also suitable for determining other suspensions in the food, pharmaceutical and mineral industries.

  17. Properties of cellulose derivatives produced from radiation—Modified cellulose pulps

    NASA Astrophysics Data System (ADS)

    Iller, Edward; Stupińska, Halina; Starostka, Paweł

    2007-07-01

    The aim of project was elaboration of radiation methods for properties modification of cellulose pulps using for derivatives production. The selected cellulose pulps were exposed to an electron beam with energy 10 MeV in a linear accelerator. After irradiation pulps underwent the structural and physico-chemical investigations. The laboratory test for manufacturing carboxymethylocellulose (CMC), cellulose carbamate (CC) and cellulose acetate (CA) with cellulose pulps irradiated dose 10 and 15 kGy have been performed. Irradiation of the pulp influenced its depolimerisation degree and resulted in the drop of viscosity of CMC. However, the expected level of cellulose activation expressed as a rise of the substitution degree or increase of the active substance content in the CMC sodium salt was not observed. In the case of cellulose esters (CC, CA) formation, the action of ionising radiation on cellulose pulps with the dose 10 and 15 kGy enables obtaiment of the average values of polimerisation degree as required for CC soluble in aqueous sodium hydroxide solution. The properties of derivatives prepared by means of radiation and classic methods were compared.

  18. Characterization of wood mulch and leachate/runoff from three wood recycling facilities.

    PubMed

    Kannepalli, Sarat; Strom, Peter F; Krogmann, Uta; Subroy, Vandana; Giménez, Daniel; Miskewitz, Robert

    2016-11-01

    Large-scale open storage of wood mulch is common practice at wood recycling facilities. During rain and snow melt, leachate with soluble compounds and suspended particles is released from mulch stockpiles. The objective of this study was to determine the quality of leachate/runoff from wood recycling facilities to evaluate its potential to contaminate receiving waterbodies. Wood mulch (n = 30) and leachate/runoff (n = 26) samples were collected over 1.5 years from three wood recycling facilities in New Jersey, USA. Differences by site were found (p < 0.05) for most of the 21 constituents tested in the solid wood mulch samples. Biochemical oxygen demand (range <20-3000 mg/L), chemical oxygen demand (134-6000 mg/L) and total suspended solids (69-401 mg/L) median concentrations of the leachate/runoff samples were comparable to those of untreated domestic wastewater. Total Kjeldahl N, total P and fecal coliform median values were slightly lower than typical wastewater values. Dose-response studies with leachate/runoff samples using zebrafish (Danio rerio) embryos showed that mortality and developmental defects typically did not occur even at the highest concentration tested, indicating low toxicity, although delayed development did occur. Based on this study, leachate/runoff from wood recycling facilities should not be released to surface waters as it is a potential source of organic contamination and low levels of nutrients. A study in which runoff from a controlled drainage area containing wood mulch of known properties is monitored would allow for better assessment of the potential impact of stormwater runoff from wood recycling facilities. PMID:27505167

  19. [Endodontic treatment of primary teeth. Pulp exposure and pulp necrosis].

    PubMed

    Gruythuysen, R J M

    2005-11-01

    With management of the deep caries in primary teeth we have to take account into the coping strategies of the patient and the state of the development of the dentition. That's why in most cases a root canal treatment of primary incisors or even a pulpotomy is not indicated. Often Intellectual Decision Not To Restore is a good alternative for treatment of deep caries in primary incisors. In deep caries lesions of primary canines and molars preferably minimal invasive techniques as indirect pulp capping are performed. In case of a exposure, the dentist can choose between several types of treatment. Improved techniques have lead to clinical satisfying results of the calcium hydroxide pulpotomy. A partial pulpotomy is if possible the treatment of choice. A resin modified glass ionomer cement is used to cover the pulp wound because it has good sealing properties and it is easy to handle. To limit the burden in young children a root canal treatment in primary teeth is seldom indicated. Overfilling with calcium hydroxide in root canal treatment of primary teeth never causes problems. PMID:16320568

  20. 21 CFR 186.1673 - Pulp.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Pulp. 186.1673 Section 186.1673 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 186.1673 Pulp....

  1. Pulp and Paper Industry Effluent Management.

    ERIC Educational Resources Information Center

    Gove, George W.

    1978-01-01

    Presents a literature review of wastes from pulp and paper industry, covering publications of 1976-77. This review focuses on: (1) receiving water, toxicity, and effluent characterization; (2) pulping liquor disposal and recovery; and (3) physicochemical and biological treatment. A list of 238 references is also presented. (HM)

  2. Changes are in Store for Pulping Technology

    ERIC Educational Resources Information Center

    Environmental Science and Technology, 1975

    1975-01-01

    The pulp and paper industry are being forced by economic considerations and air pollution regulations to consider alternatives to the use of sulfur systems, be they kraft, acid or neutral sulfite. To meet environmental requirements and combat erosion of profits, modernized non-sulfur pulping methods will increasingly appear on the scene. (BT)

  3. 21 CFR 186.1673 - Pulp.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Pulp. 186.1673 Section 186.1673 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 186.1673 Pulp....

  4. Cortical representation area of human dental pulp.

    PubMed

    Kubo, K; Shibukawa, Y; Shintani, M; Suzuki, T; Ichinohe, T; Kaneko, Y

    2008-04-01

    To elucidate the dental pulp-representing area in the human primary somatosensory cortex and the presence of A-beta fibers in dental pulp, we recorded somatosensory-evoked magnetic fields from the cortex in seven healthy persons using magnetoencephalography. Following non-painful electrical stimulation of the right maxillary first premolar dental pulp, short latency (27 ms) cortical responses on the magnetic waveforms were observed. However, no response was seen when stimulation was applied to pulpless teeth, such as devitalized teeth. The current source generating the early component of the magnetic fields was located anterior-inferiorly compared with the locations for the hand area in the primary somatosensory cortex. These results demonstrate the dental pulp representation area in the primary somatosensory cortex, and that it receives input from intradental A-beta neurons, providing a detailed organizational map of the orofacial area, by adding dental pulp to the classic "sensory homunculus". PMID:18362319

  5. Wood's Lamp Examination

    MedlinePlus

    ... dermatologists to assist in the diagnosis of various pigment and infectious disorders. The examination is performed in ... lamp. If a fungal or bacterial infection or pigment disorder is present, Wood's lamp examination can strengthen ...

  6. Isolation of Paenibacillus glucanolyticus from pulp mill sources with potential to deconstruct pulping waste.

    PubMed

    Mathews, Stephanie L; Pawlak, Joel J; Grunden, Amy M

    2014-07-01

    Black liquor is a pulping waste generated by the kraft process that has potential for downstream bioconversion. A microorganism was isolated from a black liquor sample collected from the Department of Forest Biomaterials at North Carolina State University. The organism was identified as Paenibacillus glucanolyticus using 16S rRNA sequence analysis and was shown to be capable of growth on black liquor as the sole carbon source based on minimal media growth studies. Minimal media growth curves demonstrated that this facultative anaerobic microorganism can degrade black liquor as well as cellulose, hemicellulose, and lignin. Gas chromatography-mass spectrometry was used to identify products generated by P. glucanolyticus when it was grown anaerobically on black liquor. Fermentation products which could be converted into high-value chemicals such as succinic, propanoic, lactic, and malonic acids were detected. PMID:24841577

  7. Transportation fuels from wood

    SciTech Connect

    Baker, E.G.; Elliott, D.C.; Stevens, D.J.

    1980-01-01

    The various methods of producing transportation fuels from wood are evaluated in this paper. These methods include direct liquefaction schemes such as hydrolysis/fermentation, pyrolysis, and thermochemical liquefaction. Indirect liquefaction techniques involve gasification followed by liquid fuels synthesis such as methanol synthesis or the Fischer-Tropsch synthesis. The cost of transportation fuels produced by the various methods are compared. In addition, three ongoing programs at Pacific Northwest Laboratory dealing with liquid fuels from wood are described.

  8. Impact Tests for Woods

    NASA Technical Reports Server (NTRS)

    1922-01-01

    Although it is well known that the strength of wood depends greatly upon the time the wood is under the load, little consideration has been given to this fact in testing materials for airplanes. Here, results are given of impact tests on clear, straight grained spruce. Transverse tests were conducted for comparison. Both Izod and Charpy impact tests were conducted. Results are given primarily in tabular and graphical form.

  9. Growing with wood waste

    SciTech Connect

    White, K.M.

    1995-05-01

    When officials at Regional Waste Services (Peabody, Mass.) were looking for an outlet for their used wood products in the late 1980s, they had no idea that the material would eventually turn into a whole new market for them. Simply tired of paying exorbitant disposal fees and seeking out obscure landfills willing to accept the waste, company officials decided to build and operate their own 1,000-tpd wood recycling facility. Encouraged by the immediate success of the facility, principals at Regional Waste Services, which at the time was the fifth largest independent waste hauling, transfer, and disposal firm in the US made a strategic business decision to sell their waste hauling business and to concentrate on the wood recycling operation full time. Their newly named company, Wood Recycling, Inc. (WRI, Peabody, Mass.), was officially established in July 1990. Today, nearly five years later, that decision appears to be paying off in a big way. WRI has successfully diverted thousands of tons of urban wood wastes from landfills. It also has turned that waste into an innovative line of recycled wood and paper fiber mulch lawn care products that are being marketed to consumers and commercial entities across the country.

  10. Highly Stable, Functional Hairy Nanoparticles and Biopolymers from Wood Fibers: Towards Sustainable Nanotechnology.

    PubMed

    Sheikhi, Amir; Yang, Han; Alam, Md Nur; van de Ven, Theo G M

    2016-01-01

    Nanoparticles, as one of the key materials in nanotechnology and nanomedicine, have gained significant importance during the past decade. While metal-based nanoparticles are associated with synthetic and environmental hassles, cellulose introduces a green, sustainable alternative for nanoparticle synthesis. Here, we present the chemical synthesis and separation procedures to produce new classes of hairy nanoparticles (bearing both amorphous and crystalline regions) and biopolymers based on wood fibers. Through periodate oxidation of soft wood pulp, the glucose ring of cellulose is opened at the C2-C3 bond to form 2,3-dialdehyde groups. Further heating of the partially oxidized fibers (e.g., T = 80 °C) results in three products, namely fibrous oxidized cellulose, sterically stabilized nanocrystalline cellulose (SNCC), and dissolved dialdehyde modified cellulose (DAMC), which are well separated by intermittent centrifugation and co-solvent addition. The partially oxidized fibers (without heating) were used as a highly reactive intermediate to react with chlorite for converting almost all aldehyde to carboxyl groups. Co-solvent precipitation and centrifugation resulted in electrosterically stabilized nanocrystalline cellulose (ENCC) and dicarboxylated cellulose (DCC). The aldehyde content of SNCC and consequently surface charge of ENCC (carboxyl content) were precisely controlled by controlling the periodate oxidation reaction time, resulting in highly stable nanoparticles bearing more than 7 mmol functional groups per gram of nanoparticles (e.g., as compared to conventional NCC bearing < 1 mmol functional group/g). Atomic force microscopy (AFM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) attested to the rod-like morphology. Conductometric titration, Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), dynamic light scattering (DLS), electrokinetic-sonic-amplitude (ESA) and acoustic attenuation

  11. Mesenchymal Dental Pulp Cells Attenuate Dentin Resorption in Homeostasis

    PubMed Central

    Zheng, Y.; Chen, M.; He, L.; Marão, H.F.; Sun, D.M.; Zhou, J.; Kim, S.G.; Song, S.; Wang, S.L.

    2015-01-01

    Dentin in permanent teeth rarely undergoes resorption in development, homeostasis, or aging, in contrast to bone that undergoes periodic resorption/remodeling. The authors hypothesized that cells in the mesenchymal compartment of dental pulp attenuate osteoclastogenesis. Mononucleated and adherent cells from donor-matched rat dental pulp (dental pulp cells [DPCs]) and alveolar bone (alveolar bone cells [ABCs]) were isolated and separately cocultured with primary rat splenocytes. Primary splenocytes readily aggregated and formed osteoclast-like cells in chemically defined osteoclastogenesis medium with 20 ng/mL of macrophage colony-stimulating factor (M-CSF) and 50 ng/mL of receptor activator of nuclear factor κB ligand (RANKL). Strikingly, DPCs attenuated osteoclastogenesis when cocultured with primary splenocytes, whereas ABCs slightly but significantly promoted osteoclastogenesis. DPCs yielded ~20-fold lower RANKL expression but >2-fold higher osteoprotegerin (OPG) expression than donor-matched ABCs, yielding a RANKL/OPG ratio of 41:1 (ABCs:DPCs). Vitamin D3 significantly promoted RANKL expression in ABCs and OPG in DPCs. In vivo, rat maxillary incisors were atraumatically extracted (without any tooth fractures), followed by retrograde pulpectomy to remove DPCs and immediate replantation into the extraction sockets to allow repopulation of the surgically treated root canal with periodontal and alveolar bone–derived cells. After 8 wk, multiple dentin/root resorption lacunae were present in root dentin with robust RANKL and OPG expression. There were areas of dentin resoprtion alternating with areas of osteodentin formation in root dentin surface in the observed 8 wk. These findings suggest that DPCs of the mesenchymal compartment have an innate ability to attenuate osteoclastogenesis and that this innate ability may be responsible for the absence of dentin resorption in homeostasis. Mesenchymal attenuation of dentin resorption may have implications in internal

  12. Innovations in papermaking: an LCA of printing and writing paper from conventional and high yield pulp.

    PubMed

    Manda, B M Krishna; Blok, Kornelis; Patel, Martin K

    2012-11-15

    Pulp and paper industry is facing challenges such as resource scarcity and greenhouse gas (GHG) emissions. The objective of this research is to investigate whether the use of new coatings (micro or nano TiO(2)) and different pulp types could bring savings in wood, energy, GHG emissions and other environmental impacts in comparison with conventional printing and writing paper. We studied three types of pulp, namely i) unbleached virgin kraft pulp, ii) recovered fiber, and iii) high yield virgin chemithermo-mechanical pulp (CTMP). A life cycle assessment (LCA) was conducted from cradle to grave. Applying attributional modeling, we found that wood savings amount to 60% for the nanoparticle coated recovered fiber paper and 35% for the micro TiO(2) coated CTMP paper. According to the ReCiPe single score impact assessment method, the new product configurations allow the reduction of the environmental impacts by 10-35% compared to conventional kraft paper. Applying consequential modeling, we found larger energy and GHG emission savings compared to attributional modeling because the saved wood is used for producing energy, thereby replacing fossil fuels. The nanoparticle coated recovered fiber paper offered savings of non-renewable energy use (NREU) by 100% (13GJ/ton paper) and GHG emission reduction by 75% (0.6 tonCO(2)eq./ton paper). Micro TiO(2) coated CTMP paper offered NREU savings by 25% (3GJ/ton paper) and savings of GHG emissions by 10% (0.1 tonCO(2)eq./ton paper). The taking into account of all environmental impacts with the ReCiPe single score method leads to comparable results as that of attributional modeling. We conclude that the nanoparticle coated recovered fiber paper offered the highest savings and lowest environmental impacts. However, human toxicity and ecotoxicity impacts of the nanoparticles were not included in this analysis and need further research. If this leads to the conclusion that the toxicity impacts of the nanoparticles are serious, then the

  13. [Effects of the treatment of coffee pulp, fresh or ensilaged, with calcium hydroxide, on its nutritive value].

    PubMed

    Gómez-Brenes, R; Bendaña, G; González, J M; Jarquín, R; Braham, J E; Bressani, R

    1988-03-01

    This study was carried out to determine the effects of the addition of calcium hydroxide on the chemical composition and nutritive value of fresh or ensilaged coffee pulp. Fresh or ensilaged pulp were mixed with 1, 2 and 3% of calcium hydroxide. The process was carried out during 0 and 16 hr, after which time the treated pulp was sun-dried for 36 hr until moisture content reached 12%. These samples were then analyzed for their proximate chemical composition and for some minerals (Ca, P, Na, K), as well as for caffeine, tannins and chlorogenic and caffeic acids content. Diets were then prepared from these materials, containing 15% protein and 15 or 30% fresh or ensilaged coffee pulp, and offered to weanling rats during six weeks. Information required on weight gain, food conversion, apparent digestibility and toxicity of the diets was recorded. Results of the chemical analysis revealed that the main changes found in both types of pulp as a result of the calcium hydroxide treatment were the following: a decrease in ether extract (from 4.0 to 2.5 g/100 g), crude fiber (from 18.3 to 11.9 g/100 g) and protein content (from 12.3 to 8.6 g/100 g) in an inverse relation to the amount of calcium hydroxide used. The amount of ash increased, fluctuated between 5.5 and 15.4%, depending on the amount of calcium hydroxide used. The latter affected the Ca:P ratio in the diets, where an average ratio of 7.2:1 was found in the control pulp (0% calcium hydroxide) and 59.0:1 in those treated with the highest amount of calcium hydroxide (3%). Regarding the caffeine, tannins and chlorogenic and caffeic acids contents, calcium hydroxide was effective in decreasing only tannins, more so in the fresh than in the ensilaged pulp; the decrease was in direct proportion to the amount of calcium hydroxide added and to the length of the Ca(OH)2 treatment. The results of the biological assays showed that the addition of Ca(OH)2 in either of the two time periods used and at either of the

  14. Estudo da utilizacao da biomassa florestal como fonte de produtos quimicos e energia atraves de processos quimicos e biotechnologicos (Utilization of forest biomass for chemicals and energy by chemical and biotechnological processes). Master's thesis

    SciTech Connect

    de Miranda, I.M.S.S.

    1989-04-01

    The chemical composition and the non-structural carbohydrate composition were determined for 1-year-old Eucalyptus globulus Labill trees, grown in an experimental plantation with different nutrient and water supplies (C-trees, where no treatment was made and IL-trees, which received a nutrient supply and irrigation). Leaf carbohydrates were determined for the same conditions. Pulping experiments were made using kraft cooks of eucalyptus wood. The results of the pretreatments are complemented with scanning electron microscopy observations. Average wood composition was: ash 1.6%, total extractives 5.2%, Klason lignin 21.0%, soluble lignin 3.1% (% of o.d. weight). The results did not show statistical significant differences between the two growth conditions. The average wood carbohydrate composition was: glucose 2.7%, frutose 4.1% sucrose 1.3% and starch 0.5%. The average carbohydrate composition of leaves was: glucose 1.0%, frutose 1.7%, sucrose 0.1% and starch 4.1%. The average yield for the kraft wood delinification was 49%. The saccharification of pretreated eucalyptus chips with a steam-explosion pretreatment was: For H2SO4 impregnation 26.6% and for H2O impregnation 44.2%.

  15. The microbial challenge to pulp regeneration.

    PubMed

    Fouad, A F

    2011-07-01

    Pulp regeneration is considered in cases where the dental pulp has been destroyed because of microbial irritation. Diverse oral and food-borne micro-organisms are able to invade the pulp space, form biofilm on canal walls, and infiltrate dentinal tubules. Prior to pulp regeneration procedures, the pulp space and dentinal walls need to be sufficiently disinfected to allow for and promote regeneration. The necessary level of disinfection is likely higher than that accepted for traditional endodontic therapy, because in traditional techniques the mere lowering of bacterial loads and prevention of bacterial access to periapical tissues is conducive to healing. Moreover, several of the non-specific antimicrobials used in traditional endodontic therapy may cause significant changes in remaining dentin that interfere with its inherent potential to mediate regeneration. Non-specific antimicrobials also suppress all microbial taxa, which may allow residual virulent micro-organisms to preferentially repopulate the pulp space. Therefore, it is important for endodontic pathogens to be studied by molecular methods that allow for a broad depth of coverage. It is then essential to determine the most effective protocols to disinfect the pulp space, with minimal disruption of remaining dentin. These protocols include the topical use of effective antibiotics, including newer agents that have demonstrated efficacy against endodontic pathogens. PMID:21677080

  16. A Review on Vital Pulp Therapy in Primary Teeth

    PubMed Central

    Parisay, Iman; Ghoddusi, Jamileh; Forghani, Maryam

    2015-01-01

    Maintaining deciduous teeth in function until their natural exfoliation is absolutely necessary. Vital pulp therapy (VPT) is a way of saving deciduous teeth. The most important factors in success of VPT are the early diagnosis of pulp and periradicular status, preservation of the pulp vitality and proper vascularization of the pulp. Development of new biomaterials with suitable biocompatibility and seal has changed the attitudes towards preserving the reversible pulp in cariously exposed teeth. Before exposure and irreversible involvement of the pulp, indirect pulp capping (IPC) is the treatment of choice, but after the spread of inflammation within the pulp chamber and establishment of irreversible pulpitis, removal of inflamed pulp tissue is recommended. In this review, new concepts in preservation of the healthy pulp tissue in deciduous teeth and induction of the reparative dentin formation with new biomaterials instead of devitalization and the consequent destruction of vital tissues are discussed. PMID:25598803

  17. A review on vital pulp therapy in primary teeth.

    PubMed

    Parisay, Iman; Ghoddusi, Jamileh; Forghani, Maryam

    2015-01-01

    Maintaining deciduous teeth in function until their natural exfoliation is absolutely necessary. Vital pulp therapy (VPT) is a way of saving deciduous teeth. The most important factors in success of VPT are the early diagnosis of pulp and periradicular status, preservation of the pulp vitality and proper vascularization of the pulp. Development of new biomaterials with suitable biocompatibility and seal has changed the attitudes towards preserving the reversible pulp in cariously exposed teeth. Before exposure and irreversible involvement of the pulp, indirect pulp capping (IPC) is the treatment of choice, but after the spread of inflammation within the pulp chamber and establishment of irreversible pulpitis, removal of inflamed pulp tissue is recommended. In this review, new concepts in preservation of the healthy pulp tissue in deciduous teeth and induction of the reparative dentin formation with new biomaterials instead of devitalization and the consequent destruction of vital tissues are discussed. PMID:25598803

  18. Constituents within pulp mill effluent deplete retinoid stores in white sucker and bind to rainbow trout retinoic acid receptors and retinoid X receptors.

    PubMed

    Alsop, Derek; Hewitt, Mark; Kohli, Mohan; Brown, Scott; Van Der Kraak, Glen

    2003-12-01

    Wild female and male white sucker (Catostomus commersoni) inhabiting an area receiving pulp mill effluent had reduced hepatic levels of retinol, didehydroretinol, retinyl esters, and didehydroretinyl esters, while vitamin E levels were unaffected. This disruption of the retinoid system led us to test methanol and dichloromethane extracts from the effluent of 11 pulp mills from across Canada for their ability to bind to rainbow trout (Oncorhynchus mykiss) retinoic acid receptors (RARs) from the gill and retinoid X receptors (RXRs) from the liver. Concentrated extracts of the final effluent from 6 of the 11 pulp mills were able to displace greater than 25% of the receptor-bound [3H]all-trans retinoic acid (RA) or [3H]9-cis RA from trout RARs and RXRs, respectively. The ability of the extracts to displace retinoic acid did not appear to be linked to the pulping or treatment processes. Moreover, extracts with the greatest activity came from thermomechanical mills, suggesting the compounds may originate from the wood furnish. In addition, extracts prepared from wood furnish (wood chips: white spruce [50%], lodgepole pine [47%], and balsam fir [3%]) from one mill were able to displace [3H]RA from the RARs and RXRs. The 4-hydroxy RA, a metabolite of RA that has been shown to be generated in greater quantities in fish exposed to P450-inducing xenobiotics, was able to displace [3H]all-trans RA from trout RARs as effectively as unlabeled all-trans RA. These results suggest that pulp mill effluent may impact the retinoid system of fish at multiple sites, either by decreasing hepatic retinoid stores or through contributing additional ligands (from the wood furnish) that can bind to RA receptors. PMID:14713038

  19. Vital Pulp Therapy—Current Progress of Dental Pulp Regeneration and Revascularization

    PubMed Central

    Zhang, Weibo; Yelick, Pamela C.

    2010-01-01

    Pulp vitality is extremely important for the tooth viability, since it provides nutrition and acts as biosensor to detect pathogenic stimuli. In the dental clinic, most dental pulp infections are irreversible due to its anatomical position and organization. It is difficult for the body to eliminate the infection, which subsequently persists and worsens. The widely used strategy currently in the clinic is to partly or fully remove the contaminated pulp tissue, and fill and seal the void space with synthetic material. Over time, the pulpless tooth, now lacking proper blood supply and nervous system, becomes more vulnerable to injury. Recently, potential for successful pulp regeneration and revascularization therapies is increasing due to accumulated knowledge of stem cells, especially dental pulp stem cells. This paper will review current progress and feasible strategies for dental pulp regeneration and revascularization. PMID:20454445

  20. Flexible biorefinery for producing fermentation sugars, lignin and pulp from corn stover.

    PubMed

    Kadam, Kiran L; Chin, Chim Y; Brown, Lawrence W

    2008-05-01

    A new biorefining process is presented that embodies green processing and sustainable development. In the spirit of a true biorefinery, the objective is to convert agricultural residues and other biomass feedstocks into value-added products such as fuel ethanol, dissolving pulp, and lignin for resin production. The continuous biomass fractionation process yields a liquid stream rich in hemicellulosic sugars, a lignin-rich liquid stream, and a solid cellulose stream. This paper generally discusses potential applications of the three streams and specifically provides results on the evaluation of the cellulose stream from corn stover as a source of fermentation sugars and specialty pulp. Enzymatic hydrolysis of this relatively pure cellulose stream requires significantly lower enzyme loadings because of minimal enzyme deactivation from nonspecific binding to lignin. A correlation was shown to exist between lignin removal efficiency and enzymatic digestibility. The cellulose produced was also demonstrated to be a suitable replacement for hardwood pulp, especially in the top ply of a linerboard. Also, the relatively pure nature of the cellulose renders it suitable as raw material for making dissolving pulp. This pulping approach has significantly smaller environmental footprint compared to the industry-standard kraft process because no sulfur- or chlorine-containing compounds are used. Although this option needs some minimal post-processing, it produces a higher value commodity than ethanol and, unlike ethanol, does not need extensive processing such as hydrolysis or fermentation. Potential use of low-molecular weight lignin as a raw material for wood adhesive production is discussed as well as its use as cement and feed binder. As a baseline application the hemicellulosic sugars captured in the hydrolyzate liquor can be used to produce ethanol, but potential utilization of xylose for xylitol fermentation is also feasible. Markets and values of these applications are

  1. Recent Advances in Pulp Capping Materials: An Overview

    PubMed Central

    Qureshi, Asma; E., Soujanya; Nandakumar; Pratapkumar; Sambashivarao

    2014-01-01

    Emphasis has shifted from the “doomed” organ concept of an exposed pulp to one of hope and recovery. The era of vital-pulp therapy has been greatly enhanced with the introduction of various pulp capping materials. The aim of this article is to summarize and discuss about the various and newer pulp capping materials used for protection of the dentin-pulp complex. PMID:24596805

  2. Control of the accumulation of non-process elements and organic compounds in pulp mills with bleach filtrate reuse. Quarterly report 3, January--March, 1997

    SciTech Connect

    Frederick, W.J.; Laver, M.L.; Rorrer, G.L.

    1997-05-01

    Progress during this quarter is described on four tasks. The first task involves the recovery of organic matter from bleach effluents and black liquors, separation of carbohydrates and lignin degradation products, analysis of functional groups, and characterization of carbohydrate polymers. Progress in the second task was made in the selection of model compounds. Several subtasks are complete in Task 3, but the paper summarizes progress made in the determination of the residual hemicellulose content in the pulp samples. Finally, results are given for the measurement of metal adsorption isotherms on wood pulp. Goals for the next quarter are listed.

  3. A New Technology for Treating Pulp Waste with Plasma

    NASA Astrophysics Data System (ADS)

    Feng, Xiaozhen; Tian, Zhongyu

    2009-10-01

    New methods for both the treatment of pulp waste liquor called black liquor (BL) and the recovery of chemicals by using plasma, and the concentration of BL with the freezing technique were developed. The new methods aiming at the pilot plant scale are described and the experiments in a small-scale research facility for demonstration and test are presented. The energy consumption for treating waste liquid is 1 kg/kWh. Plasma processing can reduce the costs for treatment and eliminate pollution.

  4. Polysaccharides isolated from sugar beet pulp by quaternization under acidic conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugar beet pulp was extracted and chemically modified under acidic conditions using glycidyltrimethylammonium chloride in the presence of trifuoroacetic (TFA), HCl or H3PO4. The goal was to find out how the type of acid used and quaternization could affect the yield of soluble polysaccharide, its mo...

  5. Fractionation of sugar beet pulp by introducing ion-exchange groups

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugar beet pulp (SBP) was chemically modified with the goal to utilize this method for the preparation of water-soluble polysaccharides. Yields of the trimethylammoniumhydroxypropylated (TMAHP) polysaccharide fractions prepared under vacuum in absence of NaOH or KOH, as well as their molar masses, w...

  6. Precision wood particle feedstocks

    DOEpatents

    Dooley, James H; Lanning, David N

    2013-07-30

    Wood particles having fibers aligned in a grain, wherein: the wood particles are characterized by a length dimension (L) aligned substantially parallel to the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L; the L.times.H dimensions define two side surfaces characterized by substantially intact longitudinally arrayed fibers; the W.times.H dimensions define two cross-grain end surfaces characterized individually as aligned either normal to the grain or oblique to the grain; the L.times.W dimensions define two substantially parallel top and bottom surfaces; and, a majority of the W.times.H surfaces in the mixture of wood particles have end checking.

  7. Pine wood nematode, Bursaphelenchus xylophilus.

    PubMed

    Futai, Kazuyoshi

    2013-01-01

    After devastating vast areas of pine forests in Asian countries, the pine wilt disease spread into European forests in 1999 and is causing worldwide concern. This disease involves very complicated interactions between a pathogenic nematode, its vector beetle, host pine species, and fungi in dead hosts. Pathogenicity of the pine wood nematode is determined not only by its physical and chemical traits but also by its behavioral traits. Most life history traits of the pine wood nematode, such as its phoretic relationship with vector beetles, seem to be more effective in virulent than in avirulent isolates or species. As the pathogenicity determinants, secreted enzymes, and surface coat proteins are very important, they have therefore been studied intensively. The mechanism of quick death of a large pine tree as a result of infection by a tiny nematode could be ascribed to the dysfunction of the water-conducting system caused by the death of parenchyma cells, which must have originally evolved as an inherent resistant system. PMID:23663004

  8. Fine particle emissions in three different combustion conditions of a wood chip-fired appliance - Particulate physico-chemical properties and induced cell death

    NASA Astrophysics Data System (ADS)

    Leskinen, J.; Tissari, J.; Uski, O.; Virén, A.; Torvela, T.; Kaivosoja, T.; Lamberg, H.; Nuutinen, I.; Kettunen, T.; Joutsensaari, J.; Jalava, P. I.; Sippula, O.; Hirvonen, M.-R.; Jokiniemi, J.

    2014-04-01

    A biomass combustion reactor with a moving grate was utilised as a model system to produce three different combustion conditions corresponding to efficient, intermediate, and smouldering combustion. The efficient conditions (based on a CO level of approximately 7 mg MJ-1) corresponded to a modern pellet boiler. The intermediate conditions (CO level of approximately 300 mg MJ-1) corresponded to non-optimal settings in a continuously fired biomass combustion appliance. The smouldering conditions (CO level of approximately 2200 mg MJ-1) approached a batch combustion situation. The gaseous and particle emissions were characterised under each condition. Moreover, the ability of fine particles to cause cell death was determined using the particle emissions samples. The physico-chemical properties of the emitted particles and their toxicity were considerably different between the studied combustion conditions. In the efficient combustion, the emitted particles were small in size and large in number. The PM1 emission was low, and it was composed of ash species. In the intermediate and smouldering combustion, the PM1 emission was higher, and the particles were larger in size and smaller in number. In both of these conditions, there were high-emission peaks that produced a significant fraction of the emissions. The PAH emissions were the lowest in the efficient combustion. The smouldering combustion conditions produced the largest PAH emissions. In efficient combustion conditions, the emitted fine particles had the highest potential to cause cell death. This finding was most likely observed because these fine particles were mainly composed of inorganic ash species, and their relative contents of Zn were high. Thus, even the PM1 from optimal biomass combustion might cause health effects, but in these conditions, the particle emissions per energy unit produced were considerably lower.

  9. Enhanced expression of glutamine synthetase (GS1a) confers altered fibre and wood chemistry in field grown hybrid poplar (Populus tremula X alba) (717-1B4).

    PubMed

    Coleman, Heather D; Cánovas, Francisco M; Man, Huimin; Kirby, Edward G; Mansfield, Shawn D

    2012-09-01

    Hybrid poplar (Populus tremula X P. alba) genetically engineered to express the pine cytosolic glutamine synthetase gene (GS1a) has been previously shown to display desirable field performance characteristics, including enhancements in growth and nitrogen use efficiency. Analysis of wood samples from a 3-year-old field trial of three independently transformed GS1a transgenic hybrid poplar lines revealed that, when compared with wild-type controls, ectopic expression of GS1a resulted in alterations in wood properties and wood chemistry. Included were significant enhancements in wood fibre length, wood density, microfibre angle, per cent syringyl lignin and elevated concentrations of wood sugars, specifically glucose, galactose, mannose and xylose. Total extractive content and acid-insoluble lignin were significantly reduced in wood of GS1a transgenics when compared with wild-type trees. Together, these cell wall characteristics resulted in improved wood pulping attributes, including improved lignin solubilization with no concurrent decrease in yield. Trees with increased GS1a expression have improved characteristics for pulp and paper production and hold potential as a feedstock for biofuels production. PMID:22672155

  10. Avalanches in Wood Compression.

    PubMed

    Mäkinen, T; Miksic, A; Ovaska, M; Alava, Mikko J

    2015-07-31

    Wood is a multiscale material exhibiting a complex viscoplastic response. We study avalanches in small wood samples in compression. "Woodquakes" measured by acoustic emission are surprisingly similar to earthquakes and crackling noise in rocks and laboratory tests on brittle materials. Both the distributions of event energies and of waiting (silent) times follow power laws. The stress-strain response exhibits clear signatures of localization of deformation to "weak spots" or softwood layers, as identified using digital image correlation. Even though material structure-dependent localization takes place, the avalanche behavior remains scale-free. PMID:26274428

  11. Indirect pulp therapy and stepwise excavation.

    PubMed

    Bjørndal, Lars

    2008-01-01

    Various treatment concepts have been suggested to solve the deep carious lesion dilemma. Recent systematic reviews are presented. Their conclusions are based on very few studies, and the main message is that optimal randomized clinical studies are lacking. Observational studies on indirect pulp treatment and stepwise excavation demonstrate that these treatments avoid pulp exposures, but it cannot be said which approach is best. A less invasive modified stepwise excavation approach is described, focusing on changing on active lesion into on arrested lesion even without performing an excavation close to the pulp. In Denmark and Sweden a randomized clinical multi-center trial is currently taking place, the Caries and Pulp (CAP) trial. This trial is investigating the effects of stepwise excavation over 2 visits versus 1 complete excavation of deep caries in permanent teeth. Guidelines for treatment are presented. PMID:18615988

  12. Indirect pulp therapy and stepwise excavation.

    PubMed

    Bjørndal, Lars

    2008-07-01

    Various treatment concepts have been suggested to solve the deep carious lesion dilemma. Recent systematic reviews are presented. Their conclusions are based on very few studies, and the main message is that optimal randomized clinical studies are lacking. Observational studies on indirect pulp treatment and stepwise excavation demonstrate that these treatments avoid pulp exposures, but it cannot be said which approach is best. A less invasive modified stepwise excavation approach is described, focusing on changing an active lesion into an arrested lesion even without performing an excavation close to the pulp. In Denmark and Sweden a randomized clinical multi-center trial is currently taking place, the Caries and Pulp (CAP) trial. This trial is investigating the effects of stepwise excavation over 2 visits versus 1 complete excavation of deep caries in permanent teeth. Guidelines for treatment are presented. PMID:18565369

  13. ADVANCED FILTRATION OF PULP MILL WASTES

    EPA Science Inventory

    Laboratory and pilot plants studies of reverse osmosis (hyperfiltration) and ultrafiltration of pulp mill wastes were performed by International Paper Company and Oak Ridge National Laboratory (subcontractor). Decker filtrates were treated with dynamically formed reverse osmosis ...

  14. Pulp and paper program fact sheets

    SciTech Connect

    1995-07-01

    Summaries are presented of Argonne technology transfer research projects in: sustainable forest management, environmental performance, energy performance, improved capital effectiveness, recycling, and sensors and controls. Applications in paper/pulp industry, other industries, etc. are covered.

  15. Wood energy-commercial applications

    NASA Technical Reports Server (NTRS)

    Kennel, R. P.

    1978-01-01

    Wood energy is being widely investigated in many areas of the country because of the many obvious benefits of wood fuel such as the low price per million Btus relative to coal, oil, and gas; the wide availability of noncommercial wood and the proven ability to harvest it; established technology which is reliable and free of pollution; renewable resources; better conservation for harvested land; and the potential for jobs creation. The Southeastern United States has a specific leadership role in wood energy based on its established forest products industry experience and the potential application of wood energy to other industries and institutions. Significant questions about the widespread usage of wood energy are being answered in demonstrations around the country as well as the Southeast in areas of wood storage and bulk handling; high capitalization costs for harvesting and combustion equipment; long term supply and demand contracts; and the economic feasibility of wood energy outside the forest products industry.

  16. Water-repellent coatings for surface and 3D wood processing

    NASA Astrophysics Data System (ADS)

    Debelova, N. N.; Gorlenko, N. P.; Volokitin, G. G.; Sarkisov, Yu S.; Dmitriyenko, V. P.; Zavyalova, E. N.; Zavyalov, P. B.

    2015-01-01

    The paper presents the results of research in organic chemical compositions for hydrophobic protection of wood with the use of surface and three-dimensional coating techniques of impregnation and chemical compositions. Water absorption indicators, angles of contact on the surface of treated samples are detected herein. Kinetic equation of the moisture diffusion transition in capillary-porous structure of wood is suggested.

  17. Fabrication of a superhydrophobic surface on a wood substrate

    NASA Astrophysics Data System (ADS)

    Wang, Shuliang; Shi, Junyou; Liu, Changyu; Xie, Cheng; Wang, Chengyu

    2011-09-01

    A layer of lamellar superhydrophobic coating was fabricated on a wood surface through a wet chemical process. The superhydrophobic property of the wood surface was measured by contact angle (CA) measurements. The microstructure and chemical composition of the superhydrophobic coating were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). An analytical characterization revealed that the microscale roughness of the lamellar particles was uniformly distributed on the wood surface and that a zinc stearate monolayer (with the hydrophobic groups oriented outward) formed on the ZnO surface as the result of the reaction between stearic acid and ZnO. This process transformed the wood surface from hydrophilic to superhydrophobic: the water contact angle of the surface was 151°, and the sliding angle was less than 5°.

  18. Mineral Preservatives in the Wood of Stradivari and Guarneri

    PubMed Central

    Nagyvary, Joseph; Guillemette, Renald N.; Spiegelman, Clifford H.

    2009-01-01

    Following the futile efforts of generations to reach the high standard of excellence achieved by the luthiers in Cremona, Italy, by variations of design and plate tuning, current interest is being focused on differences in material properties. The long-standing question whether the wood of Stradivari and Guarneri were treated with wood preservative materials could be answered only by the examination of wood specimens from the precious antique instruments. In a recent communication (Nature, 2006), we reported about the degradation of the wood polymers in instruments of Stradivari and Guarneri, which could be explained only by chemical manipulations, possibly by preservatives. The aim of the current work was to identify the minerals from the small samples of the maple wood which were available to us from the antique instruments. The ashes of wood from one violin and one cello by Stradivari, two violins by Guarneri, one viola by H. Jay, one violin by Gand-Bernardel were analyzed and compared with a variety of commercial tone woods. The methods of analysis were the following: back-scattered electron imaging, X-ray fluorescence maps for individual elements, wave-length dispersive spectroscopy, energy dispersive X-ray spectroscopy and quantitative microprobe analysis. All four Cremonese instruments showed the unmistakable signs of chemical treatments in the form of chemicals which are not present in natural woods, such as BaSO4, CaF2, borate, and ZrSiO4. In addition to these, there were also changes in the common wood minerals. Statistical evaluation of 12 minerals by discriminant analysis revealed: a. a difference among all four Cremona instruments, b. the difference of the Cremonese instruments from the French and English antiques, and c. only the Cremonese instruments differed from all commercial woods. These findings may provide the answer why all attempts to recreate the Stradivarius from natural wood have failed. There are many obvious implications with regard to

  19. Treatment of the Bleaching Effluent from Sulfite Pulp Production by Ceramic Membrane Filtration

    PubMed Central

    Ebrahimi, Mehrdad; Busse, Nadine; Kerker, Steffen; Schmitz, Oliver; Hilpert, Markus; Czermak, Peter

    2015-01-01

    Pulp and paper waste water is one of the major sources of industrial water pollution. This study tested the suitability of ceramic tubular membrane technology as an alternative to conventional waste water treatment in the pulp and paper industry. In this context, in series batch and semi-batch membrane processes comprising microfiltration, ultrafiltration and nanofiltration, ceramic membranes were developed to reduce the chemical oxygen demand (COD) and remove residual lignin from the effluent flow during sulfite pulp production. A comparison of the ceramic membranes in terms of separation efficiency and performance revealed that the two-stage process configuration with microfiltration followed by ultrafiltration was most suitable for the efficient treatment of the alkaline bleaching effluent tested herein, reducing the COD concentration and residual lignin levels by more than 35% and 70%, respectively. PMID:26729180

  20. Influence of process variables on the properties of laccase biobleached pulps.

    PubMed

    Martin-Sampedro, Raquel; Miranda, Jesús; García-Fuentevilla, Luisa L; Hernández, Manuel; Arias, Maria E; Diaz, Manuel J; Eugenio, Maria E

    2015-01-01

    A laccase stage can be used as a pre-treatment of a standard chemical bleaching sequence to reduce environmental concerns associated to this process. The importance of each independent variable and its influence on the properties of the bleached pulp have been studied in depth in this work, using an adaptive network-based fuzzy inference system (ANFIS) with four independent variables (laccase, buffer, mediator and oxygen) as input. Eucalyptus globulus kraft pulp was biobleached using a laccase from Pycnoporus sanguineus and a natural mediator (acetosyringone). Later, an alkaline extraction and a hydrogen peroxide treatment were applied. Most biobleaching processes showed a decrease in kappa number and an increase in brightness with no significant impact on the viscosity values, compared with the control. Oxygen was the variable with the smallest influence on the final pulp properties while the laccase and buffer solution showed a significant influence. PMID:25085529

  1. Treatment of the Bleaching Effluent from Sulfite Pulp Production by Ceramic Membrane Filtration.

    PubMed

    Ebrahimi, Mehrdad; Busse, Nadine; Kerker, Steffen; Schmitz, Oliver; Hilpert, Markus; Czermak, Peter

    2015-01-01

    Pulp and paper waste water is one of the major sources of industrial water pollution. This study tested the suitability of ceramic tubular membrane technology as an alternative to conventional waste water treatment in the pulp and paper industry. In this context, in series batch and semi-batch membrane processes comprising microfiltration, ultrafiltration and nanofiltration, ceramic membranes were developed to reduce the chemical oxygen demand (COD) and remove residual lignin from the effluent flow during sulfite pulp production. A comparison of the ceramic membranes in terms of separation efficiency and performance revealed that the two-stage process configuration with microfiltration followed by ultrafiltration was most suitable for the efficient treatment of the alkaline bleaching effluent tested herein, reducing the COD concentration and residual lignin levels by more than 35% and 70%, respectively. PMID:26729180

  2. Biological decolourisation of pulp mill effluent using white rot fungus Trametes versicolor.

    PubMed

    Srinivasan, S V; Murthy, D V S; Swaminathan, T

    2012-07-01

    The conventional biological treatment methods employed in the pulp and paper industries are not effective in reducing the colour and chemical oxygen demand (COD). The white-rot fungi are reported to have the ability to biodegrade the lignin and its derivatives. This paper is focused on the biological treatment of pulp mill effluent from a bagasse-based pulp and paper industry using fungal treatment. Experiments were conducted using the white rot fungus, Trametes versicolor in shake flasks operated in batch mode with different carbon sources. The decolourisation efficiencies of 82.5% and 80.3% were obtained in the presence of 15 g/L and 5 g/L of glucose and sucrose concentrations respectively with a considerable COD reduction. The possibility of reusing the grown fungus was examined for repeated treatment studies. PMID:24749195

  3. Classroom Demonstrations of Wood Properties.

    ERIC Educational Resources Information Center

    Foulger, A. N.

    Presented in this manual are 20 activities selected to show some of the properties of wood and how these properties relate to the cellular structure of wood. Each activity includes stated objectives, indicates materials needed, and explains procedures. Illustrations related to the activities, glossary of terms, and photographs of wood structure…

  4. A hyaluronan-based scaffold for the in vitro construction of dental pulp-like tissue.

    PubMed

    Ferroni, Letizia; Gardin, Chiara; Sivolella, Stefano; Brunello, Giulia; Berengo, Mario; Piattelli, Adriano; Bressan, Eriberto; Zavan, Barbara

    2015-01-01

    Dental pulp tissue supports the vitality of the tooth, but it is particularly vulnerable to external insults, such as mechanical trauma, chemical irritation or microbial invasion, which can lead to tissue necrosis. In the present work, we present an endodontic regeneration method based on the use of a tridimensional (3D) hyaluronan scaffold and human dental pulp stem cells (DPSCs) to produce a functional dental pulp-like tissue in vitro. An enriched population of DPSCs was seeded onto hyaluronan-based non-woven meshes in the presence of differentiation factors to induce the commitment of stem cells to neuronal, glial, endothelial and osteogenic phenotypes. In vitro experiments, among which were gene expression profiling and immunofluorescence (IF) staining, proved the commitment of DPSCs to the main components of dental pulp tissue. In particular, the hyaluronan-DPSCs construct showed a dental pulp-like morphology consisting of several specialized cells growing inside the hyaluronan fibers. Furthermore, these constructs were implanted into rat calvarial critical-size defects. Histological analyses and gene expression profiling performed on hyaluronan-DPSCs grafts showed the regeneration of osteodentin-like tissue. Altogether, these data suggest the regenerative potential of the hyaluronan-DPSC engineered tissue. PMID:25739081

  5. A Hyaluronan-Based Scaffold for the in Vitro Construction of Dental Pulp-Like Tissue

    PubMed Central

    Ferroni, Letizia; Gardin, Chiara; Sivolella, Stefano; Brunello, Giulia; Berengo, Mario; Piattelli, Adriano; Bressan, Eriberto; Zavan, Barbara

    2015-01-01

    Dental pulp tissue supports the vitality of the tooth, but it is particularly vulnerable to external insults, such as mechanical trauma, chemical irritation or microbial invasion, which can lead to tissue necrosis. In the present work, we present an endodontic regeneration method based on the use of a tridimensional (3D) hyaluronan scaffold and human dental pulp stem cells (DPSCs) to produce a functional dental pulp-like tissue in vitro. An enriched population of DPSCs was seeded onto hyaluronan-based non-woven meshes in the presence of differentiation factors to induce the commitment of stem cells to neuronal, glial, endothelial and osteogenic phenotypes. In vitro experiments, among which were gene expression profiling and immunofluorescence (IF) staining, proved the commitment of DPSCs to the main components of dental pulp tissue. In particular, the hyaluronan-DPSCs construct showed a dental pulp-like morphology consisting of several specialized cells growing inside the hyaluronan fibers. Furthermore, these constructs were implanted into rat calvarial critical-size defects. Histological analyses and gene expression profiling performed on hyaluronan-DPSCs grafts showed the regeneration of osteodentin-like tissue. Altogether, these data suggest the regenerative potential of the hyaluronan-DPSC engineered tissue. PMID:25739081

  6. Grant Wood: "American Gothic."

    ERIC Educational Resources Information Center

    Fitzgerald, Diane M.

    1988-01-01

    Presents a lesson plan which exposes students in grades 10-12 to the visual symbols and historical references contained in Grant Wood's "American Gothic." Includes background information on the artist and the painting, instructional strategies, a studio activity, and evaluation criteria. (GEA)

  7. Plasma treatment of wood

    NASA Astrophysics Data System (ADS)

    Volokitin, G. G.; Skripnikova, N. K.; Sinitsyn, V. A.; Volokitin, O. G.; Shekhovtsov, V. V.; Vaschenko, S. P.; Kuz'min, V. I.

    2016-01-01

    Plasma technology was developed to create protective-decorative coatings on the wood surfaces. Experimental investigation on applying the protective coating using the low-temperature plasma energy as well as studies of the distribution of temperature fields over the section of the treated workpiece have been carried out, and the calculated results have been compared with the experimental data.

  8. EVALUATION OF THE EFFECTIVENESS OF COATINGS IN REDUCING DISLODGEABLE ARSENIC, CHROMIUM, AND COPPER FROM CCA TREATED WOOD, INTERIM DATA REPORT

    EPA Science Inventory

    EPA is approximately 20 months into a project to evaluate the performance of wood coatings as a way to prevent arsenic, chromium and copper exposure from the surfaces of CCA treated wood. Potential dermal exposure, as measured by wipe sampling dislodgeable CCA chemical from wood ...

  9. Wet strength improvement of unbleached kraft pulp through laccase catalyzed oxidation.

    PubMed

    Lund, M; Felby, C

    2001-06-01

    Previous investigations have shown that laccase catalyzed oxidation of lignin containing wood fibers can enhance the strength of medium density fiberboards. In the present work it was investigated if laccase treatment had any impact on the tensile strength of a high yield unbleached kraft pulp. Treatment with laccase alone had only a very little effect on the wet strength of the pulp, whereas addition of lignin rich extractives increased the wet strength after the enzyme treatment significantly. A mediated oxidation gave a similar improvement of the wet tensile strength although no lignin was added to the fiber suspension. Furthermore, it was found that a heat treatment combined with a mediated oxidation gave a higher improvement in wet tensile strength than could be accounted for by the individual treatments. No change in dry tensile strength from the laccase treatment was observed. It is suggested that the observed improvement in wet tensile strength is related to polymerization of lignin on fibers in the hand sheet and/or coupling of phenoxy radicals on lignin associated to adjacent fibers. For the different mediators studied, a correlation was found between oxygen consumption upon mediated oxidation and generation of wet strength in the pulp. PMID:11397456

  10. Microbiology and biodegradation of resin acids in pulp mill effluents: a minireview.

    PubMed

    Liss, S N; Bicho, P A; Saddler, J N

    1997-07-01

    Resin acids, a group of diterpenoid carboxylic acids present mainly in softwood species, are present in many pulp mill effluents and toxic to fish in recipient waters. They are considered to be readily biodegradable. However, their removal across biological treatment systems has been shown to vary. Recent studies indicate that natural resin acids and transformation products may accumulate in sediments and pose acute and chronic toxicity to fish. Several resin acid biotransformation compounds have also been shown to bioaccumulate and to be more resistant to biodegradation than the original material. Until recently, the microbiology of resin-acid degradation has received only scant attention. Although wood-inhabiting fungi have been shown to decrease the level of resin present in wood, there is no conclusive evidence that fungi can completely degrade these compounds. In contrast, a number of bacterial isolates have recently been described which are able to utilize dehydroabietic or isopimaric acids as their sole carbon source. There appears to be an unusually high degree of substrate specificity with respect of the utilization of abietane congeners and the presence of substituents. Pimaranes do not appear to be attacked to the same extent as the abietanes. This paper reviews the occurrence, chemistry, toxicity, and biodegradation of resin acids in relation to the biological treatment of pulp and paper mill effluents. PMID:9246738

  11. Partial transparency of compressed wood

    NASA Astrophysics Data System (ADS)

    Sugimoto, Hiroyuki; Sugimori, Masatoshi

    2016-05-01

    We have developed novel wood composite with optical transparency at arbitrary region. Pores in wood cells have a great variation in size. These pores expand the light path in the sample, because the refractive indexes differ between constituents of cell and air in lumen. In this study, wood compressed to close to lumen had optical transparency. Because the condition of the compression of wood needs the plastic deformation, wood was impregnated phenolic resin. The optimal condition for high transmission is compression ratio above 0.7.

  12. Boron impregnation treatment of Eucalyptus grandis wood.

    PubMed

    Dhamodaran, T K; Gnanaharan, R

    2007-08-01

    Eucalyptus grandis is suitable for small timber purposes, but its wood is reported to be non-durable and difficult to treat. Boron compounds being diffusible, and the vacuum-pressure impregnation (VPI) method being more suitable for industrial-scale treatment, the possibility of boron impregnation of partially dry to green timber was investigated using a 6% boric acid equivalent (BAE) solution of boric acid and borax in the ratio 1:1.5 under different treatment schedules. It was found that E. grandis wood, even in green condition, could be pressure treated to desired chemical dry salt retention (DSR) and penetration levels using 6% BAE solution. Up to a thickness of 50mm, in order to achieve a DSR of 5 kg/m(3) boron compounds, the desired DSR level as per the Indian Standard for perishable timbers for indoor use, it was found that neither the moisture content of wood nor the treatment schedule posed any problem as far as the treatability of E. grandis wood was concerned. PMID:17046244

  13. More wood of better quality: intensive silviculture with rapid-growth improved Eucalyptus spp. for pulpwood

    SciTech Connect

    Campinhos, E. Jr.

    1980-01-01

    The early forests planted using Brazilian Eucalyptus seeds produced great variability in the volume of wood. In the specific case of E. saligna, there was an inability of the species to adapt itself to the local ecological system. It was obvious that new silvicultural techniques should be developed and also new species and provenances, capable of adapting to the region, should be identified. The objective was to improve wood volume yields as well as to produce a better pulp quality. The research and development work has been more successful than anticipated mainly because of the new technique of rooting cuttings developed by Aracruz, which allows propagation of vigorous parent trees, including hybrids. The production of improved seeds has also been developed. A good genetic base has been established to guarantee continuous improvement for production of seedlings to be used in routine plantations. The first results have already enabled good gains in volume, wood density, cellulose content and resistance to disease.

  14. More wood of better quality through intensive silviculture with rapid-growth improved Brazilian eucalyptus

    SciTech Connect

    Campinhos, E. Jr.

    1980-11-01

    The early forests planted using Brazilian Eucalyptus seeds produced great variability in the volume of wood. In the specific case of E. saligna, the species was unable to adapt itself to the local ecological system. It was obvious that a new silviculture technique should be developed and also that new species and provenances, capable of adapting to the region, should be identified. The objective was to improve wood volume yields as well as to produce better pulp quality. The research and development work has been more successful than anticipated, mainly because a new technique of rooting cuttings which allows propagation of vigorous parent trees, including hybrids, was developed. The production of improved seeds has also been developed. A good genetic base has been established to guarantee continuous improvement for production of seedlings to be used in routine plantings. The first results have already shown good gains in volume, wood density, cellulose content, and resistance to disease.

  15. Energy consumption in thermomechanical pulping

    SciTech Connect

    Marton, R.; Tsujimoto, N.; Eskelinen, E.

    1981-08-01

    Various components of refining energy were determined experimentally and compared with those calculated on the basis of the dimensions of morphological elements of wood. The experimentally determined fiberization energy of spruce was 6 to 60 times larger than the calculated value and that of birch 3 to 15 times larger. The energy consumed in reducing the Canadian standard freeness of isolated fibers from 500 to 150 ml was found to be approximately 1/3 of the total fiber development energy for both spruce and birch TMP. Chip size affected the refining energy consumption; the total energy dropped by approximately 30% when chip size was reduced from 16 mm to 3 mm in the case of spruce and approximately 40% for birch. 6 refs.

  16. Fabrication of superhydrophobic wood surfaces via a solution-immersion process

    NASA Astrophysics Data System (ADS)

    Liu, Changyu; Wang, Shuliang; Shi, Junyou; Wang, Chengyu

    2011-11-01

    Superhydrophobic wood surfaces were fabricated from potassium methyl siliconate (PMS) through a convenient solution-immersion method. The reaction involves a hydrogen bond assembly and a polycondensation process. The silanol was formed by reacting PMS aqueous solution with CO2, which was assembled on the wood surface via hydrogen bonds with the wood surface -OH groups. The polymethylsilsesquioxane coating was obtained through the polycondensation reaction of the hydroxyl between wood and silanol. The morphology of products were characterized using a scanning electron microscope (SEM), the surface chemical composition was determined using energy dispersive X-ray analysis (EDXA), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TGA) and contact angle measurement. Analytical results revealed that rough protuberances uniformly covered the wood surface, thus transforming the wood surface from hydrophilic to superhydrophobic. The water contact angle of the superhydrophobic wood surface was about 153° and a sliding angle was 4.6°.

  17. Lump wood combustion process

    NASA Astrophysics Data System (ADS)

    Kubesa, Petr; Horák, Jiří; Branc, Michal; Krpec, Kamil; Hopan, František; Koloničný, Jan; Ochodek, Tadeáš; Drastichová, Vendula; Martiník, Lubomír; Malcho, Milan

    2014-08-01

    The article deals with the combustion process for lump wood in low-power fireplaces (units to dozens of kW). Such a combustion process is cyclical in its nature, and what combustion facility users are most interested in is the frequency, at which fuel needs to be stoked to the fireplace. The paper defines the basic terms such as burnout curve and burning rate curve, which are closely related to the stocking frequency. The fuel burning rate is directly dependent on the immediate thermal power of the fireplace. This is also related to the temperature achieved in the fireplace, magnitude of flue gas losses and the ability to generate conditions favouring the full burnout of the fuel's combustible component, which, at once ensures the minimum production of combustible pollutants. Another part of the paper describes experiments conducted in traditional fireplaces with a grate, at which well-dried lump wood was combusted.

  18. Bacteria-tight sealing of exposed dog pulps.

    PubMed

    Wijnbergen-Buijen van Weelderen, M; van Mullem, P J

    1984-05-01

    Penetration of bacteria past filling materials can interfere with the vitality of exposed pulps. In the present study, seventy-three dog's teeth were filled--after exposure--with Cavit -W and then sealed either with a chemically or a UV polymerizing bonding. After 14 days a failure rate of 28% was demonstrated using the chemically polymerizing Concise and of 4.5% using the UV polymerizing Uvio -Bond. After 42 days the latter bonding revealed a success rate of 100%. To achieve a bacteria-tight seal of deep cavities for middle long term animal experimentation, Uvio -Bond can be used--after etching--to cover the filling material and the surrounding enamel. PMID:6234386

  19. Comparative embryotoxicity of pulp mill extracts in rainbow trout (Oncorhynchus mykiss), American flagfish (Jordanella floridae) and Japanese medaka (Oryzias latipes).

    PubMed

    Orrego, Rodrigo; Guchardi, John; Beyger, Lindsay; Krause, Rachelle; Holdway, Douglas

    2011-08-01

    This study evaluated the effects of Chilean pulp mill effluent extracts (untreated, primary and secondary treated pulp mill effluents), along with steroid standards (testosterone and 17β-estradiol) and a wood extractive standard (beta-sitosterol) on developing post-fertilized fish embryos. Our study included a cold freshwater species, rainbow trout (Oncorhynchus mykiss), and two warm freshwater species American flagfish (Jordanella floridae) and Japanese medaka (Oryzias latipes). Embryotoxicity results included delay in time to hatch and decreased hatchability but no significant egg and larvae mortality was observed in the pulp mill extract exposed embryos. By contrast, significant early hatching and increased hatchability were observed in beta-sitosterol exposed embryos, along with high mortality of testosterone exposed embryos across species. Teratogenic responses were observed in medaka embryos in all treatments. Abnormalities were detected starting at development stages 19-20 (2-4 somite stages) and included optical deformities (micro-opthalmia, 1 or 2 eyes) and lack of development of brains and hearts. Additionally, phenotypic sex identification of surviving offspring found female-biased sex-ratios in all treatments except testosterone across species. Overall, our study indicated that Chilean pulp and paper mill extractives caused embryotoxicity (post-fertilized embryos) across species and irrespective of the effluent treatment. The effects were mainly associated with delayed time to hatch, decreased hatchability, and species-specific teratogenesis. PMID:21658359

  20. Out of the woods.

    PubMed

    Jacobson, J L

    1992-01-01

    Throughout Africa, Asia and Latin America women are pushed out of forests and from their maintenance by governments and private interests for cash crop development disregarding the role of women in conserving forests. In developing countries forests are a source of wood for fuel; 60-80% of women gather wood for family needs in America. Fruits, vegetables, and nuts gathered in woods enhance their diet. Indonesian women pick bananas, mangos, guavas, and avocados from trees around their homes; in Senegal shea-nut butter is made from a local tree fruit to be sold for cash. Women provide labor also in logging, wood processing, and tree nurseries. They make charcoal and grow seedlings for sale. In India 40% of forest income and 75% of forest products export earnings are derived from nonwood resources. Poor, rural women make items out of bamboo, rattan, and rope to sell: 48% of women in an Egyptian province make a living through such activities. In India 600,000 women harvest tendu leaves for use as wrappings for cigarettes. The expansion of commercial tree plantations replacing once communal natural forests has forced poor households to spend up to 4-% of their income on fuel that they used to find in forests. Tribal women in India know the medicinal uses of 300 forest species, and women in Sierra Leone could name 31 products they obtained or made from trees and bushes, while men named only 8 items. Only 1 forestry project appraised by the World Bank during 1984-97 named women as beneficiaries, and only 1 out of 33 rural development programs funded by the World Bank did. Women provide food, fuel, and water for their families in subsistence economies, they know sustainable methods of forestry, yet they are not included in development programs whose success or failure could hinge on more attention to women's contribution and on more equity. PMID:12285836

  1. Variation in wood fibre traits among eight populations of Dipterocarpus indicus in Western Ghats, India.

    PubMed

    Prasad, A G Devi; Al-Sagheer, Nageeb A

    2012-03-01

    Wood elements and anatomical ratio of Dipterocarpus indicus were studied to evaluate variation among populations and to recommend for end selection. The variation of wood element [fibre length (FL), fibre diameter (FD), lumen diameter (LD), cell wall thickness (CWT), double wall thickness (DWT), and lumen volume (LV)] and anatomical ratio [fibre lumen area (FLA), slenderness ratio (SR) and runkel ratio (RR)] were investigated in a girth class of 100 - 120 cm among eight populations of Dipterocarpus indicus in Western Ghats, India. The study revealed a significant variations in FL (0.2426), FD (4.7019), LD (3.1689), CWT (2.7104), DWT and (5.4298) among populations. The variations in anatomical ratios were significant among populations except in case of LV. The causes of variations among populations in their wood traits were attributed to the site factors. The interaction between genetic makeup of wood traits combined with effects of edaphic, local and regional climatic conditions reflect the amount of variation among populations. The highest coefficient of variation (CV %) for FL, FD, CWT and DWT was recorded in population of Gundya whereas low coefficient of variation were recorded in the population of Makuta (FL), Devimane (FD, CWT and DWT), and Sampaje (LD). The wood of Dipterocarpus indicus was found undesirable for pulp wood but can be utilized for plywood timbers. PMID:23033683

  2. Continuous-flow wood chip reactor for biodegradation of 2,4-DCP

    SciTech Connect

    Yum, K.J.; Peirce, J.J.

    1998-02-01

    Chlorinated phenols are by-products of chlorine bleaching in numerous industries including pulp and paper mills and can be emitted from a variety of incineration processes. This research investigates the ability and efficiency of continuous-flow wood chip reactors seeded with a white-rot fungus to degrade 2,4-dichlorophenol (2,4-DCP) using wood chips as a carbon source. When 2,4-DCP was the only substrate (nonglucose treatment conditions), the wood chip reactor system had a high degradation efficiency and operated continuously without excessive fungal biomass buildup on the wood chips. In the presence of added glucose, a clogging problem and an effluent contamination problem of fungal cells are found during the reactor operating period. In addition, 2,4-DCP is degraded effectively both under low-nitrogen as well as high-nitrogen treatment conditions. The 2,4-DCP is degraded to a greater extent with small-size wood chips and hardwood chips as a carbon source. The results of this research demonstrate a potential application of wood chip reactor systems for the treatment of contaminated water while expanding the use of wasted forest products.

  3. POST BIOLOGICAL SOLIDS CHARACTERIZATION AND REMOVAL FROM PULP MILL EFFLUENTS

    EPA Science Inventory

    The study characterized the post biological solids in pulp and paper mill secondary effluent and evaluated various suspended solids removal techniques. Characterization was performed on samples from 9 mills, representing various locations, pulping processes and treatment system t...

  4. Preliminary 1H NMR study on archaeological waterlogged wood.

    PubMed

    Maccotta, Antonella; Fantazzini, Paola; Garavaglia, Carla; Donato, Ines D; Perzia, Patrizia; Brai, Maria; Morreale, Filippa

    2005-01-01

    Magnetic Resonance Relaxation (MRR) and Magnetic Resonance Imaging (MRI) are powerful tools to obtain detailed information on the pore space structure that one is unlikely to obtain in other ways. These techniques are particularly suitable for Cultural Heritage materials, because they use water 1H nuclei as a probe. Interaction with water is one of the main causes of deterioration of materials. Porous structure in wood, for example, favours the penetration of water, which can carry polluting substances and promote mould growth. A particular case is waterlogged wood from underwater discoveries and moist sites; in fact, these finds are very fragile because of chemical, physical and biological decay from the long contact with the water. When wood artefacts are brought to the surface and directly dried in air, there is the collapse of the cellular structures, and wood loses its original form and dimensions and cannot be used for study and museum exhibits. In this work we have undertaken the study of some wood finds coming from Ercolano's harbour by MRR and MRI under different conditions, and we have obtained a characterization of pore space in wood and images of the spatial distribution of the confined water in the wood. PMID:16485652

  5. Degradation of carbohydrates and lignins in buried woods

    USGS Publications Warehouse

    Hedges, J.I.; Cowie, G.L.; Ertel, J.R.; James, Barbour R.; Hatcher, P.G.

    1985-01-01

    Spruce, alder, and oak woods deposited in coastal sediments were characterized versus their modern counterparts by quantification of individual neutral sugars and lignin-derived phenols as well as by scanning electron microscopy, 13C NMR, and elemental analysis. The buried spruce wood from a 2500 yr old deposit was unaltered whereas an alder wood from the same horizon and an oak wood from an open ocean sediment were profoundly degraded. Individual sugar and lignin phenol analyses indicate that at least 90 and 98 wt% of the initial total polysaccharides in the buried alder and oak woods, respectively, have been degraded along with 15-25 wt% of the lignin. At least 75% of the degraded biopolymer has been physically lost from these samples. This evidence is supported by the SEM, 13C NMR and elemental analyses, all of which indicate selective loss of the carbohydrate moiety. The following order of stability was observed for the major biochemical constituents of both buried hardwoods: vanillyl and p-hydroxyl lignin structural units > syringyl lignin structural units > pectin > ??-cellulose > hemicellulose. This sequence can be explained by selective preservation of the compound middle lamella regions of the wood cell walls. The magnitude and selectivity of the indicated diagenetic reactions are sufficient to cause major changes in the chemical compositions of wood-rich sedimentary organic mixtures and to provide a potentially large in situ nutrient source. ?? 1985.

  6. 40 CFR Table Aa-1 to Subpart Aa of... - Kraft Pulping Liquor Emissions Factors for Biomass-Based CO2, CH4, and N2O

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Kraft Pulping Liquor Emissions Factors for Biomass-Based CO2, CH4, and N2O AA Table AA-1 to Subpart AA of Part 98 Protection of Environment... Liquor Emissions Factors for Biomass-Based CO2, CH4, and N2O Wood furnish Biomass-based emissions...

  7. 40 CFR Table Aa-1 to Subpart Aa of... - Kraft Pulping Liquor Emissions Factors for Biomass-Based CO2, CH4, and N2O

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Kraft Pulping Liquor Emissions Factors for Biomass-Based CO2, CH4, and N2O AA Table AA-1 to Subpart AA of Part 98 Protection of Environment... Liquor Emissions Factors for Biomass-Based CO2, CH4, and N2O Wood furnish Biomass-based emissions...

  8. 40 CFR Table Aa-1 to Subpart Aa of... - Kraft Pulping Liquor Emissions Factors for Biomass-Based CO2, CH4, and N2O

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Kraft Pulping Liquor Emissions Factors for Biomass-Based CO2, CH4, and N2O AA Table AA-1 to Subpart AA of Part 98 Protection of Environment... Liquor Emissions Factors for Biomass-Based CO2, CH4, and N2O Wood furnish Biomass-based emissions...

  9. Wood Composite Adhesives

    NASA Astrophysics Data System (ADS)

    Gomez-Bueso, Jose; Haupt, Robert

    The global environment, in which phenolic resins are being used for wood composite manufacture, has changed significantly during the last decade. This chapter reviews trends that are driving the use and consumption of phenolic resins around the world. The review begins with recent data on volume usage and regional trends, followed by an analysis of factors affecting global markets. In a section on environmental factors, the impact of recent formaldehyde emission regulations is discussed. The section on economics introduces wood composite production as it relates to the available adhesive systems, with special emphasis on the technical requirement to improve phenolic reactivity. Advances in composite process technology are introduced, especially in regard to the increased demands the improvements place upon adhesive system performance. The specific requirements for the various wood composite families are considered in the context of adhesive performance needs. The results of research into current chemistries are discussed, with a review of recent findings regarding the mechanisms of phenolic condensation and acceleration. Also, the work regarding alternate natural materials, such as carbohydrates, lignins, tannins, and proteinaceous materials, is presented. Finally, new developments in alternative adhesive technologies are reported.

  10. Laser Induced Fluorescence For Measurement Of Lignin Concentrations In Pulping Liquors

    NASA Astrophysics Data System (ADS)

    Horvath, J. J.; Semerjian, H. G.; Biasca, K. L.; Attala, R.

    1988-11-01

    Laser excited fluorescence of pulping liquors was investigated for use in the pulp and paper industry for process measurement and control applications. Liquors from both mill and laboratory cooks were studied. A Nd-YAG pumped dye laser was used to generate the excitation wavelength of 280 nm; measurements were also performed using a commercially available fluorometer. Measurements on mill pulping liquors gave strong signals and showed changes in the fluorescence intensity during the cook. Absorption spectra of diluted mill liquor samples showed large changes during the cook. Samples from well controlled and characterized laboratory cooks showed fluorescence to be linear with concentration over two decades with an upper limit of approximately 1000 ppm dissolved lignin. At the end of these cooks a possible chemical change was indicated by an increase in the observed fluorescence intensity. Results indicate that lignin concentrations in pulping liquors can be accurately determined with fluorescence in the linear optical region over a greater dynamic range than absorption spectroscopy. Laser induced fluorescence may also provide an indication of chemical changes occurring in the lignin structure during a cook.

  11. XPS characterization of naturally aged wood

    NASA Astrophysics Data System (ADS)

    Popescu, Carmen-Mihaela; Tibirna, Carmen-Mihaela; Vasile, Cornelia

    2009-12-01

    Wood deterioration over time (by a simultaneously biological, chemical or physical attack) is an inevitable continuous process in the environment. This process destroys all heritage resulting in a loss of valuable old wooden structures and their properties. What type of deterioration occurs and how these processes impact the wood are important questions that need consideration if old wooden structures are to be studied and properly preserved. X-ray photoelectron spectroscopy (XPS) was employed to analyze the undegraded (sound wood of ˜6 years) and degraded lime wood (˜150 years, ˜180 years, ˜250 years) from painting supports, differing in terms of the provenance, conservation status and environmental conditions of storage. Elaborated XPS analysis (comparison of C and O individual spectra, decomposition for each atomic component, calculation of O/C ratio) provided a view of the composition of the sample surfaces analyzed. On the basis of these results, it was confirmed that significant changes occurred in the first period of ageing, the ˜150 years lime wood sample having the highest percent of the carbon atoms and the lowest percentage of oxygen atoms and, respectively O/C ratio. According to our previous studies (X-ray diffraction, FTIR spectroscopy, analytical pyrolysis combined with gas chromatography/mass spectrometry and ESR-spectroscopy results), these features could be attributed to the fact that hemicelluloses and amorphous cellulose are degraded in time, whereas the crystalline fraction of cellulose decreases more slowly than the amorphous one. Consequently, the observation may be made that lignin is not so easily degraded under the environmental conditions where paintings are frequently exposed.

  12. The trait contribution to wood decomposition rates of 15 Neotropical tree species.

    PubMed

    van Geffen, Koert G; Poorter, Lourens; Sass-Klaassen, Ute; van Logtestijn, Richard S P; Cornelissen, Johannes H C

    2010-12-01

    The decomposition of dead wood is a critical uncertainty in models of the global carbon cycle. Despite this, relatively few studies have focused on dead wood decomposition, with a strong bias to higher latitudes. Especially the effect of interspecific variation in species traits on differences in wood decomposition rates remains unknown. In order to fill these gaps, we applied a novel method to study long-term wood decomposition of 15 tree species in a Bolivian semi-evergreen tropical moist forest. We hypothesized that interspecific differences in species traits are important drivers of variation in wood decomposition rates. Wood decomposition rates (fractional mass loss) varied between 0.01 and 0.31 yr(-1). We measured 10 different chemical, anatomical, and morphological traits for all species. The species' average traits were useful predictors of wood decomposition rates, particularly the average diameter (dbh) of the tree species (R2 = 0.41). Lignin concentration further increased the proportion of explained inter-specific variation in wood decomposition (both negative relations, cumulative R2 = 0.55), although it did not significantly explain variation in wood decomposition rates if considered alone. When dbh values of the actual dead trees sampled for decomposition rate determination were used as a predictor variable, the final model (including dead tree dbh and lignin concentration) explained even more variation in wood decomposition rates (R2 = 0.71), underlining the importance of dbh in wood decomposition. Other traits, including wood density, wood anatomical traits, macronutrient concentrations, and the amount of phenolic extractives could not significantly explain the variation in wood decomposition rates. The surprising results of this multi-species study, in which for the first time a large set of traits is explicitly linked to wood decomposition rates, merits further testing in other forest ecosystems. PMID:21302839

  13. Transfer, pathways, enrichment, and discharge of {sup 137}Cs and {sup 90}Sr in the pulp industry

    SciTech Connect

    Krosshavn, M.; Skipperud, L.; Lien, H.N.; Salbu, B.

    1996-09-01

    Natural and artificial radionuclides are transferred from terrestrial ecosystems via the forest industry to coastal sea water. The material processed, i.e., wood, fresh water, and bark, have low levels of radionuclides, but large amounts of raw materials are processed annually. Thus the annual flux of radionuclides is substantial. The purpose of this investigation was to study transfer, redistribution, enrichment, and discharges of {sup 137}Cs and {sup 90}Sr in pulp industry employing the sulphate process. {sup 137}Cs was highly enriched in the recovering process for sodium, while {sup 90}Sr was enriched in the recovering system for calcium compared to concentration levels in raw materials. The concentrations of {sup 137}Cs and {sup 90}Sr in bark were almost ten times the concentration level in conifer wood. No {sup 137}Cs or {sup 90}Sr could be identified in atmospheric discharges from the combustion processes. The products contained very low levels of these radionuclides. Only 5% of the annual input of {sup 137}Cs and {sup 90}Sr were found in the products. Discharges of radionuclides from this particular pulp production plant is nearly 40% of the annual {sup 137}Cs and {sup 90}Sr input. The contribution of {sup 137}Cs and {sup 90}Sr to coastal seawater is probably of minor importance providing that wood or fresh water from highly contaminated areas are not utilized. 10 refs., 6 figs., 5 tabs.

  14. Environmental control for pulp and paper mills

    SciTech Connect

    Edde, H.

    1984-01-01

    The purpose of this book is to provide the pulp and paper industry engineering community with a new source of information for use in the planning, design and operation of present and future environmental control facilities. New pollution control methods are described, and the applications of new techniques for more effectively removing a broad spectrum of contaminants from air and water discharges are discussed. The information will also be useful as text material for students in pulp and paper technology and industrial waste engineering. The book contains two parts; the first describes water and solid waste pollution control for the pulp and paper industry, while the second presents air pollution control. A condensed table of contents listing chapter titles and selected subtitles is also given.

  15. Biocompatibility of a new pulp capping cement

    PubMed Central

    Poggio, Claudio; Ceci, Matteo; Beltrami, Riccardo; Dagna, Alberto; Colombo, Marco; Chiesa, Marco

    2014-01-01

    Summary Aim The aim of the present study was to evaluate the biocompatibility of a new pulp capping material (Biodentine, Septodont) compared with reference pulp capping materials: Dycal (Dentsply), ProRoot MTA (Dentsply) and MTA-Angelus (Angelus) by using murine odontoblast cell line and Alamar blue and MTT cytotoxicity tests. Methods The citocompatibility of murine odontoblasts cells (MDPC-23) were evaluated at different times using a 24 Transwell culture plate by Alamar blue test and MTT assay. Results The results were significantly different among the pulp capping materials tested. Biocompatibility was significant different among materials with different composition. Conclusions Biodentine and MTA-based products show lower cytotoxicity varying from calcium hydroxide-based material which present higher citotoxicity. PMID:25002921

  16. Fast Curing of Composite Wood Products

    SciTech Connect

    Dr. Arthur J. Ragauskas

    2006-04-26

    The overall objective of this program is to develop low temperature curing technologies for UF and PF resins. This will be accomplished by: • Identifying the rate limiting UF and PF curing reactions for current market resins; • Developing new catalysts to accelerate curing reactions at reduced press temperatures and times. In summary, these new curing technologies will improve the strength properties of the composite wood products and minimize the detrimental effects of wood extractives on the final product while significantly reducing energy costs for wood composites. This study is related to the accelerated curing of resins for wood composites such as medium density fiberboard (MDF), particle board (PB) and oriented strandboard (OSB). The latter is frequently manufactured with a phenol-formaldehyde resin whereas ureaformaldehyde (UF) resins are usually used in for the former two grades of composite wood products. One of the reasons that hinder wider use of these resins in the manufacturing of wood composites is the slow curing speed as well as inferior bondability of UF resin. The fast curing of UP and PF resins has been identified as an attractive process development that would allow wood to be bonded at higher moisture contents and at lower press temperatures that currently employed. Several differing additives have been developed to enhance cure rates of PF resins including the use of organic esters, lactones and organic carbonates. A model compound study by Conner, Lorenz and Hirth (2002) employed 2- and 4-hydroxymethylphenol with organic esters to examine the chemical basis for the reported enhanced reactivity. Their studies suggested that the enhance curing in the presence of esters could be due to enhanced quinone methide formation or enhanced intermolecular SN2 reactions. In either case the esters do not function as true catalysts as they are consumed in the reaction and were not found to be incorporated in the polymerized resin product. An

  17. 21 CFR 872.1730 - Electrode gel for pulp testers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1730 Electrode gel for pulp testers. (a) Identification. An electrode gel for pulp testers is a device intended to be applied to the surface of a tooth... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Electrode gel for pulp testers. 872.1730...

  18. 21 CFR 872.1730 - Electrode gel for pulp testers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1730 Electrode gel for pulp testers. (a) Identification. An electrode gel for pulp testers is a device intended to be applied to the surface of a tooth... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Electrode gel for pulp testers. 872.1730...

  19. STABLE CARBON ISOTOPE ANALYSIS OF SUBFOSSIL WOOD FROM AUSTRIAN ALPS

    PubMed Central

    KŁUSEK, MARZENA; PAWEŁCZYK, SŁAWOMIRA

    2015-01-01

    The presented studies were carried out in order to check the usefulness of subfossil wood for stable isotope analysis. The aim of research was also to define the optimal method of subfossil samples preparation. Subfossil samples used during the presented studies are a part of the multi-century dendrochronological scale. This chronology originates in an area situated around a small mountain lake — Schwarzersee, in Austria. The obtained results of stable carbon isotope measurements confirmed that the method of α-cellulose extraction by the application of acidic sodium chlorite and sodium hydroxide solutions removes resins and other mobile compounds from wood. Therefore, in the case of the analysed samples, the additional chemical process of extractives removing was found to be unnecessary. Studied wood samples contained an adequate proportion of α-cellulose similar to the values characteristic for the contemporary trees. This proved an adequate wood preservation which is essential for the conduction of isotopic research. PMID:26346297

  20. Management practices for used treated wood. Final report

    SciTech Connect

    Summers, K.V.

    1995-06-01

    Pentachlorophenol, creosote, and other chemicals are used to preserve poles, crossarms, and railroad ties for the electric, telecommunications, and railroad industries. Each year, millions of pieces of treated wood are retired. This report provides information on current and potential options for management of used treated wood. Researchers conducted a literature search to acquire information on preservatives and Toxicity Characteristic Leaching Procedure data. They conducted a telephone survey of selected state agencies, landfill and incinerator/cogeneration operations, and utilities to obtain information on costs, availability of landfill disposal options, and restrictions associated with land disposal of treated wood. Simulations to evaluate the effects of landfill disposal on groundwater using EPRI`s MYGRT{trademark} analytical transport model were conducted. Current utility and railroad industry management practices for treated wood include primary reuse, disposal in nonhazardous landfills, and cogeneration. The most likely future options are increased cogeneration, with continued reuse and disposal in landfills.

  1. Integrated hydrolyzation and fermentation of sugar beet pulp to bioethanol.

    PubMed

    Rezić, Tonči; Oros, Damir; Marković, Iva; Kracher, Daniel; Ludwig, Roland; Santek, Božidar

    2013-09-28

    Sugar beet pulp is an abundant industrial waste material that holds a great potential for bioethanol production owing to its high content of cellulose, hemicelluloses, and pectin. Its structural and chemical robustness limits the yield of fermentable sugars obtained by hydrolyzation and represents the main bottleneck for bioethanol production. Physical (ultrasound and thermal) pretreatment methods were tested and combined with enzymatic hydrolysis by cellulase and pectinase to evaluate the most efficient strategy. The optimized hydrolysis process was combined with a fermentation step using a Saccharomyces cerevisiae strain for ethanol production in a single-tank bioreactor. Optimal sugar beet pulp conversion was achieved at a concentration of 60 g/l (39% of dry weight) and a bioreactor stirrer speed of 960 rpm. The maximum ethanol yield was 0.1 g ethanol/g of dry weight (0.25 g ethanol/g total sugar content), the efficiency of ethanol production was 49%, and the productivity of the bioprocess was 0.29 g/l·h, respectively. PMID:23851274

  2. Dental pulp stem cell (DPSC) isolation, characterization, and differentiation.

    PubMed

    Ferro, Federico; Spelat, Renza; Baheney, Chelsea S

    2014-01-01

    Dental pulp stem cells (DPSC) have been proposed as an alternative to pluripotent stem cells to study multilineage differentiation in vitro and for therapeutic application. Standard culture media for isolation and expansion of stem cells includes animal sera or animal-derived matrix components (e.g., Matrigel(®)). However, animal-derived reagents raise significant concerns with respect to the translational ability of these cells due to the possibility of infection and/or severe immune reaction. For these reasons clinical grade substitutes to animal components are needed in order for stem cells to reach their full therapeutic potential. In this chapter we detail a method for isolation and proliferation of DPSC in a chemically defined medium containing a low percentage of human serum. We demonstrate that in this defined culture medium a 1.25 % human serum component sufficiently replaces fetal bovine serum. This method allows for isolation of a morphologically and phenotypically uniform population of DPSCs from dental pulp tissue. DPSCs represent a rapidly proliferating cell population that readily differentiates into the osteoblastic, neuronal, myocytic, and hepatocytic lineages. This multilineage capacity of these DPSCs suggests that they may have a more broad therapeutic application than lineage-restricted adult stem cell populations such as mesenchymal stem cells. Further the culture protocol presented here makes these cells more amenable to human application than current expansion techniques for other pluripotent stem cells (embryonic stem cell lines or induced pluripotent stem cells). PMID:25173163

  3. Dynamic loss properties of wood

    SciTech Connect

    Wert, C.A.; Weller, M.; Caulfield, D.

    1984-11-01

    Internal friction and dielectric loss measurements have been made on whole wood, on cellulose, and on lignin. A prominent ..beta.. peak is seen at 200 K for frequencies around 1 Hz. This peak shifts to lower temperatures (near 160 K) when wood is heated to 475 K. We propose that this shift signifies molecular changes characteristic of the first stages of coalification of wood and lignin. Additional comparisons are made with the macromolecular structure of amber, oil shale, and synthetic polymers.

  4. Dynamic loss properties of wood

    SciTech Connect

    Wert, C.A.; Weller, M.; Caulfield, D.

    1984-11-01

    Internal friction and dielectric loss measurements have been made on wood, on cellulose, and on lignin. A prominent ..beta.. peak is seen at 200 K for frequencies around 1 Hz. This peak shifts to lower temperatures (near 160 K) when wood is heated to 475 K. We propose that this shift signifies molecular changes characteristic of the first stages of coalification of wood and lignin. Additional comparisons are made with the macromolecular structure of amber, oil shale, and synthetic polymers.

  5. Mill Integration-Pulping, Stream Reforming and Direct Causticization for Black Liquor Recovery

    SciTech Connect

    Adriaan van Heiningen

    2007-06-30

    MTCI/StoneChem developed a steam reforming, fluidized bed gasification technology for biomass. DOE supported the demonstration of this technology for gasification of spent wood pulping liquor (or 'black liquor') at Georgia-Pacific's Big Island, Virginia mill. The present pre-commercial R&D project addressed the opportunities as well as identified negative aspects when the MTCI/StoneChem gasification technology is integrated in a pulp mill production facility. The opportunities arise because black liquor gasification produces sulfur (as H{sub 2}S) and sodium (as Na{sub 2}CO{sub 3}) in separate streams which may be used beneficially for improved pulp yield and properties. The negative aspect of kraft black liquor gasification is that the amount of Na{sub 2}CO{sub 3} which must be converted to NaOH (the so called causticizing requirement) is increased. This arises because sulfur is released as Na{sub 2}S during conventional kraft black liquor recovery, while during gasification the sodium associated Na{sub 2}S is partly or fully converted to Na{sub 2}CO{sub 3}. The causticizing requirement can be eliminated by including a TiO{sub 2} based cyclic process called direct causticization. In this process black liquor is gasified in the presence of (low sodium content) titanates which convert Na{sub 2}CO{sub 3} to (high sodium content) titanates. NaOH is formed when contacting the latter titanates with water, thereby eliminating the causticizing requirement entirely. The leached and low sodium titanates are returned to the gasification process. The project team comprised the University of Maine (UM), North Carolina State University (NCSU) and MTCI/ThermoChem. NCSU and MTCI are subcontractors to UM. The principal organization for the contract is UM. NCSU investigated the techno-economics of using advanced pulping techniques which fully utilize the unique cooking liquors produced by steam reforming of black liquor (Task 1). UM studied the kinetics and agglomeration problems of

  6. Overcoming the Recalcitrance of Cellulosic Biomass by Value Prior to Pulping: Cooperative Research and Development Final Report, CRADA Number CRD-07-221

    SciTech Connect

    Lowell, A.

    2012-04-01

    The Value Prior to Pulping (VPP) project goal was to demonstrate the technical and commercial feasibility of introducing a new value stream into existing pulp and paper mills. Essentially the intent was to transfer the energy content of extracted hemicellulose from electricity and steam generated in the recovery boiler to a liquid transportation fuel. The hemicellulose fraction was extracted prior to pulping, fractionated, or conditioned if necessary, and fermented to ethanol. Commercial adaptation of the process to wood hemicelluloses was a prerequisite for using this less currently valued component available from biomass and wood. These hemicelluloses are predominately glucurono-xylan in hardwoods and galactoglucomannan in softwoods (with a significant softwood component of an arabino-xylan) and will yield fermentation substrates different from cellulose. NREL provided its expertise in the area of fermentation host evaluation using its Zymomonas strains on the CleanTech Partner's (CTP) VPP project. The project was focused on the production of fuel ethanol and acetic acid from hemicellulose streams generated from wood chips of industrially important hardwood and softwood species. NREL was one of four partners whose ethanologen was tested on the hydrolyzed extracts. The use of commercially available enzymes to treat oligomeric sugar extracts was also investigated and coupled with fermentation. Fermentations by NREL were conducted with the Zymomonas mobilis organism with most of the work being performed with the 8b strain. The wood extracts hydrolyzed and/or fermented by NREL were those derived from maple, mixed southern hardwoods, and loblolly pine. An unhydrolyzed variant of the mixed southern hardwood extract possessed a large concentration of oligomeric sugars and enzymatic hydrolysis was performed with a number of enzymes, followed by fermentation. The fermentation of the wood extracts was carried out at bench scale in flasks or small bioreactors, with a

  7. Microwave Measurements of Low Pulp Concentration in Papermaking Process

    NASA Astrophysics Data System (ADS)

    Nakayama, Shigeru

    1994-06-01

    A method of microwave measurements of low pulp concentrations in the papermaking process is developed using a coaxial cavity resonator with an inner slot antenna. We measure the attenuation of the resonant peak of the cavity resonator which is related to the pulp concentration. The pulp concentration up to 10.1% is measured, and then the linear relationship between the attenuation and low pulp concentrations down to 0.6% is determined. By this method, a low pulp concentration can be measured within the standard deviation of 0.03% by linear approximation.

  8. CYTOTOXICITY AND BIOCOMPATIBILITY OF DIRECT AND INDIRECT PULP CAPPING MATERIALS

    PubMed Central

    Modena, Karin Cristina da Silva; Casas-Apayco, Leslie Caroll; Atta, Maria Teresa; Costa, Carlos Alberto de Souza; Hebling, Josimeri; Sipert, Carla Renata; Navarro, Maria Fidela de Lima; Santos, Carlos Ferreira

    2009-01-01

    There are several studies about the cytotoxic effects of dental materials in contact with the pulp tissue, such as calcium hydroxide (CH), adhesive systems, resin composite and glass ionomer cements. The aim of this review article was to summarize and discuss the cytotoxicity and biocompatibility of materials used for protection of the dentin-pulp complex, some components of resin composites and adhesive systems when placed in direct or indirect contact with the pulp tissue. A large number of dental materials present cytotoxic effects when applied close or directly to the pulp, and the only material that seems to stimulate early pulp repair and dentin hard tissue barrier formation is CH. PMID:20027424

  9. Method for rapidly determining a pulp kappa number using spectrophotometry

    DOEpatents

    Chai, Xin-Sheng; Zhu, Jun Yong

    2002-01-01

    A system and method for rapidly determining the pulp kappa number through direct measurement of the potassium permanganate concentration in a pulp-permanganate solution using spectrophotometry. Specifically, the present invention uses strong acidification to carry out the pulp-permanganate oxidation reaction in the pulp-permanganate solution to prevent the precipitation of manganese dioxide (MnO.sub.2). Consequently, spectral interference from the precipitated MnO.sub.2 is eliminated and the oxidation reaction becomes dominant. The spectral intensity of the oxidation reaction is then analyzed to determine the pulp kappa number.

  10. Chelating efficiency and thermal, mechanical and decay resistance performances of chitosan copper complex in wood-polymer composites.

    PubMed

    Lu, John Z; Duan, Xinfang; Wu, Qinglin; Lian, Kun

    2008-09-01

    Wood-polymer composites (WPC) have been extensively used for building products, outdoor decking, automotive, packaging materials, and other applications. WPC is subject to fungal and termite attacks due to wood components enveloped in the thermoplastic matrix. Much effort has been made to improve decay resistance of WPC using zinc borate and other chemicals. In this study, chitosan copper complex (CCC) compounds were used as a potential preservative for wood-HDPE composites. CCC was formulated by reacting chitosan with copper salts under controlled conditions. Inductively coupled plasma (ICP) analytical results indicated that chitosan had high chelating efficiency with copper cations. CCC-treated wood-HDPE composites had a thermal behavior similar to untreated and zinc borate-treated wood-HDPE composites. Incorporation of CCC in wood-HDPE composites did not significantly influence board density of the resultant composites, but had a negative effect on tensile strength at high CCC concentration. In comparison with solid wood and the untreated wood-HDPE composites, 3% CCC-treated wood-HDPE composites significantly improved the decay resistance against white rot fungus Trametes versicolor and brown rot fungus Gloeophyllum trabeum. Especially, CCC-treated wood-HDPE composites were more effectively against the brown rot than the untreated and chitosan-treated wood-HDPE composites. Moreover, CCC-treated wood-HDPE composites performed well as zinc borate-treated wood-HDPE composites on fungal decay resistance. Accordingly, CCC can be effectively used as a preservative for WPC. PMID:18248812

  11. Wood Substitutes; A Base Syllabus on Wood Technology.

    ERIC Educational Resources Information Center

    Eastern Kentucky Univ., Richmond.

    This curriculum guide is for use by college instructors concerned with expanding traditional woodworking programs. It was developed in a National Defense Education Act summer institute and is based on an outline provided by members of a previous institute. The content concerns wood substitutes which are made to resemble wood and are often used…

  12. Effects of Dates Pulp Extract and Palm Sap (Phoenix dactylifera L.) on Gastrointestinal Transit Activity in Healthy Rats

    PubMed Central

    Souli, Abdellaziz; Rtibi, Kaïs; Chehimi, Latifa; Sakly, Mohsen; Amri, Mohamed; El-Benna, Jamel

    2014-01-01

    Abstract The current study was performed to measure the chemical composition and the effects of dates pulp extract and palm sap on gastrointestinal transit (GIT) activity in healthy adult rats. In this respect, male Wistar rats fasted for 24 hours were used and received per orally (p.o.) sodium chloride (NaCl) (0,9%) (control group) or various doses of dates pulp extract (150 and 300 mg/kg, body weight [b.w.]) and palm sap (0.4 and 4 mL/kg, b.w.). Two other groups of rats (batch tests) received, respectively, clonidine (an alpha-2 adrenergic agonist, 1 mg/kg, b.w.) and yohimbine (an alpha-2 adrenergic antagonist, 2mg/kg, b.w.). Chemical analysis showed that the dates pulp extract is more rich in sugars and minerals, especially potassium and sucrose, as compared with palm sap composition. On the other hand, in vivo study showed that the aqueous dates pulp extract significantly, and dose dependently, increased the GIT activity while the palm sap slightly increased it. Moreover, a converse effect has been observed using clonidine (decreased 68%) and yohimbine (increased 33%) on the GIT activity. These findings suggest that dates pulp extract and palm sap have a stimulating effect on GIT activity in rats and confirm their use in traditional Tunisian medicine for the treatment of constipation. PMID:24611963

  13. Selective Enrichment of a Methanol-Utilizing Consortium Using Pulp and Paper Mill Waste Streams

    NASA Astrophysics Data System (ADS)

    Mockos, Gregory R.; Smith, William A.; Loge, Frank J.; Thompson, David N.

    Efficient utilization of carbon inputs is critical to the economic viability of the current forest products sector. Input carbon losses occur in various locations within a pulp mill, including losses as volatile organics and wastewater. Opportunities exist to capture this carbon in the form of value-added products such as biodegradable polymers. Wasteactivated sludge from a pulp mill wastewater facility was enriched for 80 days for a methanol-utilizing consortium with the goal of using this consortium to produce biopolymers from methanol-rich pulp mill waste streams. Five enrichment conditions were utilized: three high-methanol streams from the kraft mill foul condensate system, one methanol-amended stream from the mill wastewater plant, and one methanol-only enrichment. Enrichment reactors were operated aerobically in sequencing batch mode at neutral pH and 25°C with a hydraulic residence time and a solids retention time of 4 days. Non-enriched waste activated sludge did not consume methanol or reduce chemical oxygen demand. With enrichment, however, the chemical oxygen demand reduction over 24-h feed/ decant cycles ranged from 79 to 89%, and methanol concentrations dropped below method detection limits. Neither the non-enriched waste-activated sludge nor any of the enrichment cultures accumulated polyhydroxyalkanoates (PHAs) under conditions of nitrogen sufficiency. Similarly, the non-enriched waste activated sludge did not accumulate PHAs under nitrogen-limited conditions. By contrast, enriched cultures accumulated PHAs to nearly 14% on a dry weight basis under nitrogen-limited conditions. This indicates that selectively enriched pulp mill waste activated sludge can serve as an inoculum for PHA production from methanol-rich pulp mill effluents.

  14. Selective enrichment of a methanol-utilizing consortium using pulp & paper mill waste streams

    SciTech Connect

    Gregory R. Mockos; William A. Smith; Frank J. Loge; David N. Thompson

    2007-04-01

    Efficient utilization of carbon inputs is critical to the economic viability of the current forest products sector. Input carbon losses occur in various locations within a pulp mill, including losses as volatile organics and wastewater . Opportunities exist to capture this carbon in the form of value-added products such as biodegradable polymers. Waste activated sludge from a pulp mill wastewater facility was enriched for 80 days for a methanol-utilizing consortium with the goal of using this consortium to produce biopolymers from methanol-rich pulp mill waste streams. Five enrichment conditions were utilized: three high-methanol streams from the kraft mill foul condensate system, one methanol-amended stream from the mill wastewater plant, and one methanol-only enrichment. Enrichment reactors were operated aerobically in sequencing batch mode at neutral pH and 25°C with a hydraulic residence time and a solids retention time of four days. Non-enriched waste activated sludge did not consume methanol or reduce chemical oxygen demand. With enrichment, however, the chemical oxygen demand reduction over 24 hour feed/decant cycles ranged from 79 to 89 %, and methanol concentrations dropped below method detection limits. Neither the non-enriched waste activated sludge nor any of the enrichment cultures accumulated polyhydroxyalkanoates (PHAs) under conditions of nitrogen sufficiency. Similarly, the non-enriched waste activated sludge did not accumulate PHAs under nitrogen limited conditions. By contrast, enriched cultures accumulated PHAs to nearly 14% on a dry weight basis under nitrogen limited conditions. This indicates that selectively-enriched pulp mill waste activated sludge can serve as an inoculum for PHA production from methanol-rich pulp mill effluents.

  15. Selective enrichment of a methanol-utilizing consortium using pulp and paper mill waste streams.

    PubMed

    Mockos, Gregory R; Smith, William A; Loge, Frank J; Thompson, David N

    2008-03-01

    Efficient utilization of carbon inputs is critical to the economic viability of the current forest products sector. Input carbon losses occur in various locations within a pulp mill, including losses as volatile organics and wastewater. Opportunities exist to capture this carbon in the form of value-added products such as biodegradable polymers. Waste-activated sludge from a pulp mill wastewater facility was enriched for 80 days for a methanol-utilizing consortium with the goal of using this consortium to produce biopolymers from methanol-rich pulp mill waste streams. Five enrichment conditions were utilized: three high-methanol streams from the kraft mill foul condensate system, one methanol-amended stream from the mill wastewater plant, and one methanol-only enrichment. Enrichment reactors were operated aerobically in sequencing batch mode at neutral pH and 25 degrees C with a hydraulic residence time and a solids retention time of 4 days. Non-enriched waste activated sludge did not consume methanol or reduce chemical oxygen demand. With enrichment, however, the chemical oxygen demand reduction over 24-h feed/decant cycles ranged from 79 to 89%, and methanol concentrations dropped below method detection limits. Neither the non-enriched waste-activated sludge nor any of the enrichment cultures accumulated polyhydroxyalkanoates (PHAs) under conditions of nitrogen sufficiency. Similarly, the non-enriched waste activated sludge did not accumulate PHAs under nitrogen-limited conditions. By contrast, enriched cultures accumulated PHAs to nearly 14% on a dry weight basis under nitrogen-limited conditions. This indicates that selectively enriched pulp mill waste activated sludge can serve as an inoculum for PHA production from methanol-rich pulp mill effluents. PMID:18418753

  16. Influence of different types of pulp treatment during isolation in the obtention of human dental pulp stem cells

    PubMed Central

    Viña-Almunia, Jose; Borras, Consuelo; Gambini, Juan; El Alamy, Marya; Viña, Jose

    2016-01-01

    Background Different methods have been used in order to isolate dental pulp stem cells. The aim of this study was to study the effect of different types of pulp treatment during isolation, under 3% O2 conditions, in the time needed and the efficacy for obtaining dental pulp stem cells. Material and Methods One hundred and twenty dental pulps were used to isolate dental pulp stem cells treating the pulp tissue during isolation using 9 different methods, using digestive, disgregation, or mechanical agents, or combining them. The cells were positive for CD133, Oct4, Nestin, Stro-1, CD34 markers, and negative for the hematopoietic cell marker CD-45, thus confirming the presence of mesenchymal stem cells. The efficacy of dental pulp stem cells obtention and the minimum time needed to obtain such cells comparing the 9 different methods was analyzed. Results Dental pulp stem cells were obtained from 97 of the 120 pulps used in the study, i.e. 80.8% of the cases. They were obtained with all the methods used except with mechanical fragmentation of the pulp, where no enzymatic digestion was performed. The minimum time needed to isolate dental pulp stem cells was 8 hours, digesting with 2mg/ml EDTA for 10 minutes, 4mg/ml of type I collagenase, 4mg/ml of type II dispase for 40 minutes, 13ng/ml of thermolysine for 40 minutes and sonicating the culture for one minute. Conclusions Dental pulp stem cells were obtained in 97 cases from a series of 120 pulps. The time for obtaining dental pulp stem cells was reduced maximally, without compromising the obtention of the cells, by combining digestive, disgregation, and mechanical agents. Key words:Dental pulp stem cells, mesenchymal stem cells, isolation method. PMID:26946201

  17. Archaea prevalence in inflamed pulp tissues

    PubMed Central

    Efenberger, Magdalena; Agier, Justyna; Pawłowska, Elżbieta

    2015-01-01

    Archaea have been detected in several ecological niches of the human body such as the large intestine, skin, vagina as well as the oral cavity. At present, archaea are recognized as nonpathogenic microorganisms. However, some data indicate that they may be involved in the etiopathogenesis of several diseases, including intestinal diseases as well as oral diseases: periodontitis, peri-implantitis and endodontitis. In this study, on the basis of 16S rRNA gene sequence analysis, we examined whether archaea might be present in inflamed pulp tissues and contribute to the development of endodontic infection. In comparison, we also determined selected bacterial species associated with endodontitis. We detected archaea in 85% of infected endodontic samples. In addition, Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola were present in inflamed pulp tissue samples and Treponema denticola occurred with the highest frequency (70%). Further analysis revealed the presence of methanogenic archaea in analyzed samples. Direct sequencing of archaeal 16S rRNA gene PCR products indicated the occurrence of methanogenic archaea in inflamed pulp tissues; phylogenetically most similar were Methanobrevibacter oralis and Methanobrevibacter smithii. Therefore, our results show that methanogenic archaea are present in inflamed pulp tissues and may participate in the development of endodontic infection. PMID:26557034

  18. 21 CFR 872.1720 - Pulp tester.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Pulp tester. 872.1720 Section 872.1720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... battery powered device intended to evaluate the pulpal vitality of teeth by employing high...

  19. Anaerobic digestion of pulp and paper mill wastewater and sludge.

    PubMed

    Meyer, Torsten; Edwards, Elizabeth A

    2014-11-15

    Pulp and paper mills generate large amounts of waste organic matter that may be converted to renewable energy in form of methane. The anaerobic treatment of mill wastewater is widely accepted however, usually only applied to few selected streams. Chemical oxygen demand (COD) removal rates in full-scale reactors range between 30 and 90%, and methane yields are 0.30-0.40 m(3) kg(-1) COD removed. Highest COD removal rates are achieved with condensate streams from chemical pulping (75-90%) and paper mill effluents (60-80%). Numerous laboratory and pilot-scale studies have shown that, contrary to common perception, most other mill effluents are also to some extent anaerobically treatable. Even for difficult-to-digest streams such as bleaching effluents COD removal rates range between 15 and 90%, depending on the extent of dilution prior to anaerobic treatment, and the applied experimental setting. Co-digestion of different streams containing diverse substrate can level out and diminish toxicity, and may lead to a more robust microbial community. Furthermore, the microbial population has the ability to become acclimated and adapted to adverse conditions. Stress situations such as toxic shock loads or temporary organic overloading may be tolerated by an adapted community, whereas they could lead to process disturbance with an un-adapted community. Therefore, anaerobic treatment of wastewater containing elevated levels of inhibitors or toxicants should be initiated by an acclimation/adaptation period that can last between a few weeks and several months. In order to gain more insight into the underlying processes of microbial acclimation/adaptation and co-digestion, future research should focus on the relationship between wastewater composition, reactor operation and microbial community dynamics. The potential for engineering and managing the microbial resource is still largely untapped. Unlike in wastewater treatment, anaerobic digestion of mill biosludge (waste activated

  20. Manganese Peroxidase, Produced by Trametes versicolor during Pulp Bleaching, Demethylates and Delignifies Kraft Pulp

    PubMed Central

    Paice, M. G.; Reid, I. D.; Bourbonnais, R.; Archibald, F. S.; Jurasek, L.

    1993-01-01

    Previous work has shown that Trametes (Coriolus) versicolor bleaches kraft pulp brownstock with the concomitant release of methanol. In this work, the fungus is shown to produce both laccase and manganese peroxidase (MnP) but not lignin peroxidase during pulp bleaching. MnP production was enhanced by the presence of pulp and/or Mn(II) ions. The maximum level of secreted MnP was coincident with the maximum rate of fungal bleaching. Culture filtrates isolated from bleaching cultures produced Mn(II)- and hydrogen peroxide-dependent pulp demethylation and delignification. Laccase and MnP were separated by ion-exchange chromatography. Purified MnP alone produced most of the demethylation and delignification exhibited by the culture filtrates. On the basis of the methanol released and the total and phenolic methoxyl contents of the pulp, it appears that MnP shows a preference for the oxidation of phenolic lignin substructures. The extensive increase in brightness observed in the fungus-treated pulp was not found with MnP alone. Therefore, either the MnP effect must be optimized or other enzymes or compounds from the fungus are also required for brightening. Images PMID:16348850

  1. Pulp stem cells: implication in reparative dentin formation.

    PubMed

    Dimitrova-Nakov, Sasha; Baudry, Anne; Harichane, Yassine; Kellermann, Odile; Goldberg, Michel

    2014-04-01

    Many dental pulp stem cells are neural crest derivatives essential for lifelong maintenance of tooth functions and homeostasis as well as tooth repair. These cells may be directly implicated in the healing process or indirectly involved in cell-to-cell diffusion of paracrine messages to resident (pulpoblasts) or nonresident cells (migrating mesenchymal cells). The identity of the pulp progenitors and the mechanisms sustaining their regenerative capacity remain largely unknown. Taking advantage of the A4 cell line, a multipotent stem cell derived from the molar pulp of mouse embryo, we investigated the capacity of these pulp-derived precursors to induce in vivo the formation of a reparative dentin-like structure upon implantation within the pulp of a rodent incisor or a first maxillary molar after surgical exposure. One month after the pulp injury alone, a nonmineralized fibrous matrix filled the mesial part of the coronal pulp chamber. Upon A4 cell implantation, a mineralized osteodentin was formed in the implantation site without affecting the structure and vitality of the residual pulp in the central and distal parts of the pulp chamber. These results show that dental pulp stem cells can induce the formation of reparative dentin and therefore constitute a useful tool for pulp therapies. Finally, reparative dentin was also built up when A4 progenitors were performed by alginate beads, suggesting that alginate is a suitable carrier for cell implantation in teeth. PMID:24698687

  2. The relationship between pulp calcifications and salivary gland calcifications

    PubMed Central

    Kaswan, Sumita; Maheshwari, Sneha; Rahman, Farzan; Khandelwal, Suneet

    2014-01-01

    Aim: Pulp stones are discrete calcified bodies found in the dental pulp. Sialolithasis is the most common salivary gland disease. The aim of the present study was to determine the relationship between the pulp stones and salivary gland stones. Material and Methods: 196 patients were randomly selected from the out patient department for the study. The periapical radiographs for all patients were evaluated for the presence or absence of the narrowing of dental pulp chambers and pulp canals. The intra oral occlusal radiographs were also evaluated to determine the presence or absence of salivary stones. The results were compared and analyzed using the Chi-square test (p<0.001). Results: Salivary gland calcifications were detected in 5 patients. 191 patients had pulp narrowing and 118 patients had pulp stones. There was no statistical correlation between pulp narrowing and salivary stones (p>0.001) and also between pulp stones and salivary gland stones (p>0.001). Conclusions: However, the incidental findings of salivary gland stones on intra oral occlusal radiographs can provide useful information in the early diagnosis of the condition, but in the present study no significant relationship was found between the presence of pulp stones and salivary gland stones. Key words:Pulp stone, salivary gland stone, periapical radiograph, occlusal radiograph. PMID:25674311

  3. Potassium hydroxide pulping of rice straw in biorefinery initiatives.

    PubMed

    Jahan, M Sarwar; Haris, Fahmida; Rahman, M Mostafizur; Samaddar, Purabi Rani; Sutradhar, Shrikanta

    2016-11-01

    Rice straw is supposed to be one of the most important lignocellulosic raw materials for pulp mill in Asian countries. The major problem in rice straw pulping is silica. The present research is focused on the separation of silica from the black liquor of rice straw pulping by potassium hydroxide (KOH) and pulp evaluation. Optimum KOH pulping conditions of rice straw were alkali charge 12% as NaOH, cooking temperature 150°C for 2h and material to liquor ratio, 1:6. At this condition pulp yield was 42.4% with kappa number 10.3. KOH pulp bleached to 85% brightness by D0EpD1 bleaching sequences with ClO2 consumption of 25kg/ton of pulp. Silica and lignin were separated from the black liquor of KOH pulping. The amount of recovered silica, lignin and hemicelluloses were 10.4%, 8.4% and 13.0%. The papermaking properties of KOH pulp from rice straw were slightly better than those of corresponding NaOH pulp. PMID:27518034

  4. Pulp and dentin tissue engineering and regeneration: current progress

    PubMed Central

    Huang, George TJ

    2009-01-01

    Dental pulp tissue is vulnerable to infection. Entire pulp amputation followed by pulp-space disinfection and filling with an artificial rubber-like material is employed to treat the infection – commonly known as root-canal therapy. Regeneration of pulp tissue has been difficult as the tissue is encased in dentin without collateral blood supply except from the root apical end. However, with the advent of the concept of modern tissue engineering and the discovery of dental stem cells, regeneration of pulp and dentin has been tested. This article will review the early attempts to regenerate pulp tissue and the current endeavor of pulp and dentin tissue engineering, and regeneration. The prospective outcome of the current advancement in this line of research will be discussed. PMID:19761395

  5. Pulp and dentin tissue engineering and regeneration: current progress.

    PubMed

    Huang, George T J

    2009-09-01

    Dental pulp tissue is vulnerable to infection. Entire pulp amputation followed by pulp-space disinfection and filling with an artificial rubber-like material is employed to treat the infection - commonly known as root-canal therapy. Regeneration of pulp tissue has been difficult as the tissue is encased in dentin without collateral blood supply except from the root apical end. However, with the advent of the concept of modern tissue engineering and the discovery of dental stem cells, regeneration of pulp and dentin has been tested. This article will review the early attempts to regenerate pulp tissue and the current endeavor of pulp and dentin tissue engineering, and regeneration. The prospective outcome of the current advancement in this line of research will be discussed. PMID:19761395

  6. Environmental Influences on Wood Chemistry and Density of Populus and Loblolly Pine

    SciTech Connect

    Tuskan, G.A.

    2006-08-11

    The objectives of the study are to: (1) determine the degree to which physical and chemical wood properties vary in association with environmental and silvicultural practices in Populus and loblolly pine and (2) develop and verify species-specific empirical models in an effort to create a framework for understanding environmental influences on wood quality.

  7. Integration of the Mini-Sulfide Sulfite Anthraquinone (MSS-AQ) Pulping Process and Black Liquor Gasification in a Pulp Mill

    SciTech Connect

    Hasan Jameel, North Carolina State University; Adrianna Kirkman, North Carolina State University; Ravi Chandran,Thermochem Recovery International Brian Turk Research Triangle Institute; Brian Green, Research Triangle Institute

    2010-01-27

    As many of the recovery boilers and other pieces of large capital equipment of U.S. pulp mills are nearing the end of their useful life, the pulp and paper industry will soon need to make long-term investments in new technologies. The ability to install integrated, complete systems that are highly efficient will impact the industry’s energy use for decades to come. Developing a process for these new systems is key to the adoption of state-of-the-art technologies in the Forest Products industry. This project defined an integrated process model that combines mini-sulfide sulfite anthraquinone (MSS-AQ) pulping and black liquor gasification with a proprietary desulfurization process developed by the Research Triangle Institute. Black liquor gasification is an emerging technology that enables the use of MSS-AQ pulping, which results in higher yield, lower bleaching cost, lower sulfur emissions, and the elimination of causticization requirements. The recently developed gas cleanup/absorber technology can clean the product gas to a state suitable for use in a gas turbine and also regenerate the pulping chemicals needed to for the MSS-AQ pulping process. The combination of three advanced technologies into an integrated design will enable the pulping industry to achieve a new level of efficiency, environmental performance, and cost savings. Because the three technologies are complimentary, their adoption as a streamlined package will ensure their ability to deliver maximum energy and cost savings benefits. The process models developed by this project will enable the successful integration of new technologies into the next generation of chemical pulping mills. When compared to the Kraft reference pulp, the MSS-AQ procedures produced pulps with a 10-15 % yield benefit and the ISO brightness was 1.5-2 times greater. The pulp refined little easier and had a slightly lower apparent sheet density (In both the cases). At similar levels of tear index the MSS-AQ pulps also

  8. Histopathology, enzyme activities, and PAH metabolites in English sole collected near coastal pulp mills

    SciTech Connect

    Brand, D.G.

    1995-12-31

    The bottom-feeding flatfish, English sole (Pleuronectes vetulus), is widely distributed along the B.C. Pacific coast and fulfills a majority of the requirements as a sentinel species for environmental effects monitoring programs. Studies involving the use of histopathological, biochemical, and chemical tools with English sole collected near the vicinity of B.C. pulp mills are currently being conducted. Analysis, to date, has revealed idiopathic liver lesions to be strongly dependent on location of capture with a prevalence of 30% preneoplastic and neoplastic lesions found in fish collected near pulp mills. All fish residing near pulp mills show hepatocellular hemosiderosis, an iron storage disorder. The mixed-function oxidizing enzyme, EROD, was found to be induced in fish collected near pulp mills. However, the levels of conjugating enzymes, GST and UDP-GT, were found to be unchanged when compared with reference fish. PAH metabolites, measured as FACs in bile, are also present in English sole collected from the mill sites and the conjugated derivatives are presently being identified by HPLC/ES-MS techniques, The relationships between these observations will be discussed.

  9. Fractionation of sugar beet pulp into pectin, cellulose, and arabinose by arabinases combined with ultrafiltration

    SciTech Connect

    Spangnuolo, M.; Crecchio, C.; Pizzigallo, M.D.R.; Ruggiero, P.

    1999-09-20

    Incubation of beet pulp with two arabinases ({alpha}-L-arabinofuranosidase and endo-arabinase), used singularly or in combination at different units of activity per gram of beet pulp, caused the hydrolysis of arabinasn, which produced a hydrolyzate consisting mainly of arabinose. Pectin and a residue enriched with cellulose were subsequently separated from the incubation mixture. The best enzymatic hydrolysis results were obtained when 100 U/g of beet pulp of each enzyme worked synergistically with yields of 100% arabinose and 91.7% pectin. These yields were higher than those obtained with traditional chemical hydrolysis. The pectin fraction showed a low content of neutral sugar content and the cellulose residue contained only a small amount of pentoses. Semicontinuous hydrolysis with enzyme recycling in an ultrafiltration unit was also carried out to separate arabinose, pectin, and cellulose from beet pulp in 7 cycles of hydrolysis followed by ultrafiltration. The yields of separation were similar to those obtained in batch experiments, with an enzyme consumption reduced by 3.5 times and some significant advantages over batch processes.

  10. Ongoing evaluation of sources and factors affecting emissions from engineered wood products

    SciTech Connect

    Turner, S.L.; Martin, C.B.; Sheldon, L.S.; Baskir, J.N.; Howard, E.M.

    1998-09-01

    The paper describes an ongoing evaluation of sources and factors affecting emissions from engineered wood products. It summarizes early results from emissions testing of engineered wood products. These tests have shown the emissions of volatile organic compounds (VOCs) from the alcohol, aldehyde/ketone, ester, aromatic and aliphatic hydrocarbon, monoterpene, sesquiterpene, indene, and alkyl ether chemical families from engineered wood samples. This information will be used to target pollution prevention approaches, such as alternate materials and production technologies for raw board and engineered wood products, for reducing VOC emissions.

  11. Refractory organic pollutants and toxicity in pulp and paper mill wastewaters.

    PubMed

    Lindholm-Lehto, Petra C; Knuutinen, Juha S; Ahkola, Heidi S J; Herve, Sirpa H

    2015-05-01

    This review describes medium and high molecular weight organic material found in wastewaters from pulp and paper industry. The aim is to review the versatile pollutants and the analysis methods for their determination. Among other pollutants, biocides, extractives, and lignin-derived compounds are major contributors to harmful effects, such as toxicity, of industrial wastewaters. Toxicity of wastewaters from pulp and paper mills is briefly evaluated including the methods for toxicity analyses. Traditionally, wastewater purification includes mechanical treatment followed by chemical and/or biological treatment processes. A variety of methods are available for the purification of industrial wastewaters, including aerobic and anaerobic processes. However, some fractions of organic material, such as lignin and its derivatives, are difficult to degrade. Therefore, novel chemical methods, including electrochemical and oxidation processes, have been developed for separate use or in combination with biological treatment processes. PMID:25647495

  12. Recycling of wood chips and wheat dregs for sludge processing.

    PubMed

    Lin, Y F; Jing, S R; Lee, D Y

    2001-01-01

    A Buchner filtration study was conducted to investigate the effect on sludge dewatering of adding organic waste solids (wood chips or wheat dregs) to sludge after chemical preconditioning (with ferric chloride or alum). Increasing the dose of wood chips or wheat dregs enhanced sludge filtration performance and increased the energy content of the filter cake, but did not consistently increase the total filtrate removed. The additional filtrate removal was found to balance the inert solids load only when the chemical preconditioner used did not result in sufficient coagulation of the sludge and the skeleton builder dose was low (< or = 90%). Accordingly, various dose ranges of wood chips and wheat dregs are suggested for different sludge management schemes. PMID:11131800

  13. Biorefining of softwoods using ethanol organosolv pulping: preliminary evaluation of process streams for manufacture of fuel-grade ethanol and co-products.

    PubMed

    Pan, Xuejun; Arato, Claudio; Gilkes, Neil; Gregg, David; Mabee, Warren; Pye, Kendall; Xiao, Zhizhuang; Zhang, Xiao; Saddler, John

    2005-05-20

    Pulps with residual lignin ranging from 6.4-27.4% (w/w) were prepared from mixed softwoods using a proprietary biorefining technology (the Lignol process) based on aqueous ethanol organosolv extraction. The pulps were evaluated for bioconversion using enzymatic hydrolysis of the cellulose fraction to glucose and subsequent fermentation to ethanol. All pulps were readily hydrolyzed without further delignification. More than 90% of the cellulose in low lignin pulps (< or =18.4% residual lignin) was hydrolyzed to glucose in 48 h using an enzyme loading of 20 filter paper units/g cellulose. Cellulose in a high lignin pulp (27.4% residual lignin) was hydrolyzed to >90% conversion within 48 h using 40 filter paper units/g. The pulps performed well in both sequential and simultaneous saccharification and fermentation trials indicating an absence of metabolic inhibitors. Chemical and physical analyses showed that lignin extracted during organosolv pulping of softwood is a suitable feedstock for production of lignin-based adhesives and other products due to its high purity, low molecular weight, and abundance of reactive groups. Additional co-products may be derived from the hemicellulose sugars and furfural recovered from the water-soluble stream. PMID:15772945

  14. Natural composite of wood as replacement material for ostechondral bone defects.

    PubMed

    Aho, Allan J; Rekola, Jami; Matinlinna, Jukka; Gunn, Jarmo; Tirri, Teemu; Viitaniemi, Pertti; Vallittu, Pekka

    2007-10-01

    Deciduous wood, birch, pretreated by a technique combining heat and water vapor was applied for the reconstruction of bone defects in the knee joint of rabbits. It was observed that wood showed characteristic properties to be incorporated by the host bone during observation time of 4, 8, and 20 weeks. The natural channel structure of wood served as a porous scaffold, allowing host bone growth as small islets into the wood implants. The other properties of heat-treated wood, such as bioactivity, good handling properties, and sufficient biomechanical properties, might be additional favorable factors for the application of wood as a natural composite material for bone and cartilage repair. At the interface of the surfaces of wood and living bone, bonding occurred. The Chemical Interface Model for bonding bone to wood consists of the reactive ions, such as hydroxyl groups --OH, and covalent bonding as well as hydrogen bonding, which originate from both wood and bone. The bone tissue trauma, with its reactive Ca(2+) and PO(4) (3-) ions, proteins, and collagen, available for interaction at ionic and nanolevel, are associated with the complicated chemistry in the cellular response of the early bone healing process. It was concluded that heat-treated wood acted like a porous biomaterial scaffold, allowing ongrowth and ingrowth of bone and cartilage differentiation on its surface, and demonstrating osteoconductive contact, bonding at the interface. PMID:17318823

  15. Microscopic characterization of tension wood cell walls of Japanese beech (Fagus crenata) treated with ionic liquids.

    PubMed

    Kanbayashi, Toru; Miyafuji, Hisashi

    2016-09-01

    Tension wood that is an abnormal part formed in angiosperms has been barely used for wood industry. In this study, to utilize the tension wood effectively by means of liquefaction using ionic liquid, we performed morphological and topochemical determination of the changes in tension wood of Japanese beech (Fagus crenata) during ionic liquid treatment at the cellular level using light microscopy, scanning electron microscopy and confocal Raman microscopy. Ionic liquid treatment induced cell wall swelling in tension wood. Changes in the tissue morphology treated with ionic liquids were different between normal wood and tension wood, moreover the types of ionic liquids. The ionic liquid 1-ethyl-3-methylimidazolium chloride liquefied gelatinous layers rapidly, whereas 1-ethylpyridinium bromide liquefied slowly but delignified selectively. These novel insights into the deconstruction behavior of tension wood cell walls during ionic liquid treatment provide better understanding of the liquefaction mechanism. The obtained knowledge will contribute to development of an effective chemical processing of tension wood using ionic liquids and lead to efficient use of wood resources. PMID:27285953

  16. Nanoindentation techniques for the cell walls of wood

    NASA Astrophysics Data System (ADS)

    Jakes, Joseph Eugene

    There is a recognized need in forest products research to better understand how the mechanical properties of wood derive from the basic polymer components that make up the wood. For development of new engineered wood products there is the need to understand how chemical additives and adhesives interact with wood polymers and influence properties at the cellular level. To meet these needs I have developed nanoindentation techniques for probing the mechanical properties of the cell walls in wood. There are two, key results of this research. The first is a newly invented structural compliance method for isolating the properties of local regions within materials and excluding artifacts brought about by neighboring edges including free edges and interfaces between dissimilar cell wall layers. The second consists of methods to obtain viscoplastic and viscoelastic data over as wide a range of deformation rate as possible. The broadband nanoindentation creep (BNC) technique assesses the viscoplastic properties over 5 orders of magnitude in deformation rate (-10-4 to 10 s-1). Viscoelastic measurements can be made with unloading times ranging from 0.01 to 100 s, resulting in viscoelastic data that span four orders of magnitude in frequency or inverse time (˜10-3 to 10 s-1). To demonstrate the efficacy of these techniques, experiments are performed on a range of materials including fused silica, silicon, molybdenum, siliconon-insulator layered specimen, poly (methylmetacrylate), polycarbonate, polystyrene, wood cells in loblolly pine (Pinus taeda ), and a polypropylene-wood composite. Finally, the structural compliance method and BNC are combined to explore polymeric methylene diphenyl diisocyanate (pMDI)-wood interactions. The data suggest that pMDI polymerizes in situ to create an interpenetrating polymer network.

  17. Bioremediation of agro-based pulp mill effluent by microbial consortium comprising autochthonous bacteria.

    PubMed

    Kumar, Virendra; Dhall, Purnima; Kumar, Rita; Prakash Singh, Yogendra; Kumar, Anil

    2012-01-01

    Small-scale agro-based pulp and paper mills are characterized as highly polluting industries. These mills use Kraft pulping process for paper manufacturing due to which toxic lignified chemicals are released into the environment. Lack of infrastructure, technical manpower, and research and development facilities restricts these mills to recover these chemicals. Therefore, the chemical oxygen demand (COD) of the emanating stream is quite high. For solving the above problem, four bacteria were isolated from the premises of agro-based pulp and paper mill which were identified as species of Pseudomonas, Bacillus, Pannonibacter, and Ochrobacterum. These bacteria were found capable of reducing COD up to 85%-86.5% in case of back water and 65-66% in case of back water : black liquor (60:40), respectively, after acclimatization under optimized conditions (pH 6.8, temperature 35°C, and shaking 200 rpm) when the wastewater was supplemented with nitrogen and phosphorus as trace elements. PMID:22448126

  18. Bioremediation of Agro-Based Pulp Mill Effluent by Microbial Consortium Comprising Autochthonous Bacteria

    PubMed Central

    Kumar, Virendra; Dhall, Purnima; Kumar, Rita; Prakash Singh, Yogendra; Kumar, Anil

    2012-01-01

    Small-scale agro-based pulp and paper mills are characterized as highly polluting industries. These mills use Kraft pulping process for paper manufacturing due to which toxic lignified chemicals are released into the environment. Lack of infrastructure, technical manpower, and research and development facilities restricts these mills to recover these chemicals. Therefore, the chemical oxygen demand (COD) of the emanating stream is quite high. For solving the above problem, four bacteria were isolated from the premises of agro-based pulp and paper mill which were identified as species of Pseudomonas, Bacillus, Pannonibacter, and Ochrobacterum. These bacteria were found capable of reducing COD up to 85%–86.5% in case of back water and 65-66% in case of back water : black liquor (60 : 40), respectively, after acclimatization under optimized conditions (pH 6.8, temperature 35°C, and shaking 200 rpm) when the wastewater was supplemented with nitrogen and phosphorus as trace elements. PMID:22448126

  19. Pulp Stone, Haemodialysis, End-stage Renal Disease, Carotid Atherosclerosis

    PubMed Central

    Patil, Santosh; Sinha, Nidhi

    2013-01-01

    Objectives: The aim of this study was to determine the relationship between the presence of pulp calcification and carotid artery calcification on the dental panoramic radiographs in End Stage Renal Disease (ESRD) patients who were on haemodialysis. Methods: A total of 112 End Stage Renal Disease (ESRD) patients on who were haemodialysis participated in this study. The periapical and the panoramic radiographs for all the patients were evaluated for the presence or absence of the narrowing of the dental pulps and for pulp stones in the pulp chambers and the pulp canals. The panoramic radiographs were also evaluated to determine the carotid calcification. Results: Carotid calcifications were detected in none of the patients. 84 (74.99%) patients had dental pulp narrowing, and 38 (33.92%) patients had pulp stones. There was no statistical correlation between pulp narrowing and Carotid Artery Calcification (CAC) in the haemodialysis patient group. There was also no statistical correlation between pulp stones and CAC in the haemodialysis patients. Conclusion: However, the incidental finding of CAC on a panoramic radiograph can provide life-saving information for the vascular disease patients, but in the present study, no significant relationship was found between the presence of the pulpal calcification and CAC in the ESRD patients who were on haemodialysis. Therefore, the presence of pulp calcification does not seem to serve as a diagnostic marker for carotid atherosclerosis. PMID:23905147

  20. Wood-burning stove

    SciTech Connect

    Hicks, A.W.; Jolicoeur, G.D.

    1981-05-19

    A wood stove is of all welded steel plate construction except for the door which is of heavy cast iron. When the door is closed, the only source of combustion air is through an adjustable air inlet on the face of the door. The door is hollow and serves to preheat the incoming air. The inner wall of the door divides the incoming air into lower and upper, primary and secondary, respectively, combustion air flows. The stove has an internal upper baffle running from rear to front which helps to promote air flow and combustion efficiency and to knock out entrained matter from the products of combustion. The flue connection is in the rear of the stove above the baffle and is stepped into the back of the stove to allow the stove to be fitted against a wall.

  1. Wood Bond Testing

    NASA Technical Reports Server (NTRS)

    1989-01-01

    A joint development program between Hartford Steam Boiler Inspection Technologies and The Weyerhaeuser Company resulted in an internal bond analyzer (IBA), a device which combines ultrasonics with acoustic emission testing techniques. It is actually a spinoff from a spinoff, stemming from a NASA Lewis invented acousto-ultrasonic technique that became a system for testing bond strength of composite materials. Hartford's parent company, Acoustic Emission Technology Corporation (AET) refined and commercialized the technology. The IBA builds on the original system and incorporates on-line process control systems. The IBA determines bond strength by measuring changes in pulsar ultrasonic waves injected into a board. Analysis of the wave determines the average internal bond strength for the panel. Results are displayed immediately. Using the system, a mill operator can adjust resin/wood proportion, reduce setup time and waste, produce internal bonds of a consistent quality and automatically mark deficient products.

  2. Pulping effluents: Biological treatment. (Latest citations from the Paper and Board, Printing, and Packaging Industries Research Associations database). Published Search

    SciTech Connect

    Not Available

    1993-12-01

    The bibliography contains citations concerning effluent and wastewater biological treatment and disposal in the pulping industry. Effluent toxicity; treatment plant management, treatment systems, and equipment design; combined mechanical and biological treatment processes; biological degradation treatment in chemical pulp mills; and the handling and disposal of solid wastes are among the topics discussed. Also examined are performance evaluations of biological treatment processes in domestic and foreign plants in full scale operation and pilot programs. (Contains a minimum of 168 citations and includes a subject term index and title list.)

  3. Characteristics of wood ash and influence on soil properties and nutrient uptake: an overview.

    PubMed

    Demeyer, A; Voundi Nkana, J C; Verloo, M G

    2001-05-01

    Wood industries and power plants generate enormous quantities of wood ash. Disposal in landfills has been for long a common method for removal. New regulations for conserving the environment have raised the costs of landfill disposal and added to the difficulties for acquiring new sites for disposal. Over a few decades a number of studies have been carried out on the utilization of wood ashes in agriculture and forestry as an alternative method for disposal. Because of their properties and their influence on soil chemistry the utilization of wood ashes is particularly suited for the fertility management of tropical acid soils and forest soils. This review principally focuses on ash from the wood industry and power plants and considers its physical, chemical and mineralogical characteristics, its effect on soil properties, on the availability of nutrient elements and on the growth and chemical composition of crops and trees, as well as its impact on the environment. PMID:11272014

  4. Detection of organochlorine compounds formed during the contact of sodium hypochlorite with dentin and dental pulp.

    PubMed

    Varise, Tiago Gilioli; Estrela, Carlos; Guedes, Débora Fernandes Costa; Sousa-Neto, Manoel Damião; Pécora, Jesus Djalma

    2014-01-01

    This study used gas chromatography-mass spectrometry (GC-MS) to detect the products formed during the contact of sodium hypochlorite (NaOCl) with bovine pulp and dentin. For analysis of the products formed in the volatile phase, 11 mg of bovine pulp tissue were placed in contact with 0.5%, 2.5% and 5.25% NaOCl until complete tissue dissolution occurred. The solid phase microextraction (SPME) fiber was exposed inside the container through the cover membrane and immediately injected into the GC-MS system. 30 mg of the of dentin were kept in contact with NaOCl, and then the SPME fiber was exposed inside the container through the cover membrane for adsorption of the products and injected into the GC-MS system. The same protocol was used for the aqueous phase. For analysis of the volatile compounds, the final solution was extracted using pure ethyl ether. The suspended particulate phase of the mixture was aspirated, and ether was separated from the aqueous phase of the solution. The ether containing the products that resulted from the chemical interaction of dentin and pulp with the NaOCl was filtered and then injected into the GC-MS system for analysis of the aqueous phase. The aqueous and volatile phases of both dentin and pulp showed the formation of chloroform, hexachloroethane, dichloromethylbenzene and benzaldehyde. In conclusion, organochlorine compounds are generated during the contact of dentin and pulp with NaOCl at concentrations of 0.5%, 2.5% and 5.25%. PMID:25140714

  5. Kinetics of liquid-solid reactions in naphthenic acid conversion and Kraft pulping

    NASA Astrophysics Data System (ADS)

    Yang, Ling

    Two liquid-solid reactions, in which the morphology of the solid changes as the reactions proceeds, were examined. One is the NA conversion in oil by decarboxylation on metal oxides and carbonates, and the other is the Kraft pulping in which lignin removal by delignification reaction. In the study of the NA conversion, CaO was chosen as the catalyst for the kinetic study from the tested catalysts based on NA conversion. Two reaction mixtures, carrier oil plus commercial naphthenic acids and heavy vacuum gas oil (HVGO) from Athabasca bitumen, were applied in the kinetic study. The influence of TAN, temperature, and catalyst loading on the NA conversion and decarboxylation were studied systematically. The results showed that the removal rate of TAN and the decarboxylation of NA were both independent of the concentration of NA over the range studied, and significantly dependent on reaction temperature. The data from analyzing the spent catalyst demonstrated that calcium naphthenate was an intermediate of the decarboxylation reaction of NA, and the decomposition of calcium naphthenate was a rate-determining step. In the study on the delignification of the Kraft pulping, a new mechanism was proposed for the heterogeneous delignification reaction during the Kraft pulping process. In particular, the chemical reaction mechanism took into account the heterogeneous nature of Kraft pulping. Lignin reacted in parallel with sodium hydroxide and sodium sulfide. The mechanism consists of three key kinetic steps: (1) adsorption of hydroxide and hydrosulfide ions on lignin; (2) surface reaction on the solid surface to produce degraded lignin products; and (3) desorption of degradation products from the solid surface. The most important step for the delignification process is the surface reaction, rather than the reactions occurring in the liquid phase. A kinetic model has, thus, been developed based on the proposed mechanism. The derived kinetic model showed that the mechanism

  6. In Vivo Experiments with Dental Pulp Stem Cells for Pulp-Dentin Complex Regeneration

    PubMed Central

    Kim, Sunil; Shin, Su-Jung; Song, Yunjung; Kim, Euiseong

    2015-01-01

    In recent years, many studies have examined the pulp-dentin complex regeneration with DPSCs. While it is important to perform research on cells, scaffolds, and growth factors, it is also critical to develop animal models for preclinical trials. The development of a reproducible animal model of transplantation is essential for obtaining precise and accurate data in vivo. The efficacy of pulp regeneration should be assessed qualitatively and quantitatively using animal models. This review article sought to introduce in vivo experiments that have evaluated the potential of dental pulp stem cells for pulp-dentin complex regeneration. According to a review of various researches about DPSCs, the majority of studies have used subcutaneous mouse and dog teeth for animal models. There is no way to know which animal model will reproduce the clinical environment. If an animal model is developed which is easier to use and is useful in more situations than the currently popular models, it will be a substantial aid to studies examining pulp-dentin complex regeneration. PMID:26688616

  7. RELATIVE LEACHING AND AQUATIC TOXICITY OF PRESSURE-TREATED WOOD PRODUCTS USING BATCH LEACHING TESTS

    EPA Science Inventory

    Samples of southern yellow pine dimensional lumber, each treated with one of five different waterborne chemical preservatives, were leached using 18-hour batch leaching tests. The wood preservatives included chromated copper arsenate (CCA), alkaline copper quaternary (ACQ), coppe...

  8. Activation of the NLRP3/caspase-1 inflammasome in human dental pulp tissue and human dental pulp fibroblasts.

    PubMed

    Jiang, Wenkai; Lv, Haipeng; Wang, Haijing; Wang, Diya; Sun, Shukai; Jia, Qian; Wang, Peina; Song, Bing; Ni, Longxing

    2015-08-01

    The NLRP3/caspase-1 inflammasome pathway plays an important role in cellular immune defence against bacterial infection; however, its function in human dental pulp tissue and human dental pulp fibroblasts remains poorly understood. We demonstrate that NLRP3 protein expression occurs to a greater extent in pulp tissue with irreversible pulpitis than in normal pulp tissue and in tissue with reversible pulpitis. Caspase-1 is present in its active (cleaved) form only in pulp tissue with irreversible pulpitis. NLRP3 and caspase-1 are expressed in the odontoblast layers in normal human dental pulp tissue, whereas in inflamed pulp tissue, the odontoblast layers are disrupted and dental pulp cells are positive for NLRP3 and caspase-1. Additionally, we investigate the role of the NLRP3/caspase-1 inflammasome pathway in human dental pulp fibroblasts and show that ATP activates the P2X7 receptor on the cell membrane triggering K(+) efflux and inducing the gradual recruitment of the membrane pore pannexin-1. Extracellular lipopolysaccharide is able to penetrate the cytosol and activate NLRP3. Furthermore, the low intracellular K(+) concentration in the cytosol triggers reactive oxygen species generation, which also induces the NLRP3 inflammasome. Thus, the NLRP3/caspase-1 pathway has a biological role in the innate immune response mounted by human dental pulp fibroblasts. PMID:25684031

  9. Expression of high mobility group box 1 in inflamed dental pulp and its chemotactic effect on dental pulp cells

    SciTech Connect

    Zhang, Xufang; Jiang, Hongwei; Gong, Qimei; Fan, Chen; Huang, Yihua; Ling, Junqi

    2014-08-08

    Highlights: • HMGB1 translocated from nucleus to cytoplasm during dental pulp inflammation. • HMGB1and its receptor RAGE were up-regulated in hDPCs under LPS stimulation. • HMGB1 enhanced hDPCs migration and induces cytoskeleton reorganization. • HMGB1 may play a critical role in dental pulp repair during inflamed state. - Abstract: High mobility group box 1 protein (HMGB1) is a chromatin protein which can be released extracellularly, eliciting a pro-inflammatory response and promoting tissue repair process. This study aimed to examine the expression and distribution of HMGB1 and its receptor RAGE in inflamed dental pulp tissues, and to assess its effects on proliferation, migration and cytoskeleton of cultured human dental pulp cells (DPCs). Our data demonstrated that cytoplasmic expression of HMGB1 was observed in inflamed pulp tissues, while HMGB1 expression was confined in the nuclei in healthy dental pulp. The mRNA expression of HMGB1 and RAGE were significantly increased in inflamed pulps. In in vitro cultured DPCs, expression of HMGB1 in both protein and mRNA level was up-regulated after treated with lipopolysaccharide (LPS). Exogenous HMGB1 enhanced DPCs migration in a dose-dependent manner and induced the reorganization of f-actin in DPCs. Our results suggests that HMGB1 are not only involved in the process of dental pulp inflammation, but also play an important role in the recruitment of dental pulp stem cells, promoting pulp repair and regeneration.

  10. Current trends in primary tooth pulp therapy.

    PubMed

    Haney, Kevin L

    2007-10-01

    Pulp therapy in the primary dentition remains a technique generating a tremendous amount of study. Formocresol has been and continues to be the most commonly used intrapulpal medicament despite its known ability to escape the microcirculation of the pulp. Ferric sulfate has gained significant favor as a result of formocresol's disadvantages, though at the cost of requiring a much more acute awareness of the potential for remaining disease and its ability to mask that process. Mineral trioxide aggregate perhaps offers the best immediate alternative to either of the above though at this time it is still cost-prohibitive in a practice that actively treats many children. And, as MTA has no fixative properties of its own, accurately analyzing the extent of the pulpal disease becomes even more critical to the overall success of the procedure. As with other techniques in dentistry, the debate is sure to continue for severl years to come. PMID:18019933

  11. Tissue Engineering Considerations in Dental Pulp Regeneration

    PubMed Central

    Nosrat, Ali; Kim, Jong Ryul; Verma, Prashant; S. Chand, Priya

    2014-01-01

    Regenerative endodontic procedure is introduced as a biologically based treatment for immature teeth with pulp necrosis. Successful clinical and radiographic outcomes following regenerative procedures have been reported in landmark case reports. Retrospective studies have shown that this conservative treatment allows for continued root development and increases success and survival rate of the treated teeth compared to other treatment options. Although the goal of treatment is regeneration of a functional pulp tissue, histological analyses show a different outcome. Developing predictable protocols would require the use of key elements for tissue engineering: stem cells, bioactive scaffolds, and growth factors. In this study we will review the evidence based steps and outcomes of regenerative endodontics. PMID:24396373

  12. Optical determination of dental pulp vitality.

    PubMed

    Schmitt, J M; Webber, R L; Walker, E C

    1991-04-01

    In this preliminary study, we explored the feasibility of employing photoplethysmography and pulse oximetry to assess the status of the blood circulation in the dental pulp. A simple photometer that measures diffuse light transmission at 575 nm was built to record tooth plethysmograms, and the ability to distinguish vital from surgically devitalized teeth of a dog using plethysmography was demonstrated. As an extension of the photoplethysmographic technique, red-infrared pulse oximetry applied to the measurement of the oxygen saturation (SO2) of blood in the pulp was also examined using an in vitro test setup. Results suggest that the measurement of relative SO2 changes is feasible, but standard dual-wavelength pulse oximetry does not enable determination of SO2 independent of tooth geometry and sensor placement. PMID:1855796

  13. Hydrothermal carbonization of pulp mill streams.

    PubMed

    Wikberg, Hanne; Ohra-Aho, Taina; Honkanen, Mari; Kanerva, Heimo; Harlin, Ali; Vippola, Minnamari; Laine, Christiane

    2016-07-01

    The progress of the conversion, the yield, the structure and the morphology of the produced carbonaceous materials as a function of time were systematically studied with pyrolysis-GC/FID and FESEM microscope. The conversion of galactoglucomannan, bleached kraft pulp and TEMPO oxidized cellulose nanofibrils followed the reaction route of glucose being slower though with fibrous material, higher molar mass and viscosity. The conversion of kraft lignin was minor following completely different reaction route. Carbonaceous particles of different shape and size were produced with yields between 23% and 73% after 4h with being higher for lignin than carbohydrates. According to the results, potential pulp mill streams represent lignocellulosic resources for generation of carbonaceous materials. PMID:27107340

  14. Novel fiber optic dental pulp vitalometer

    NASA Astrophysics Data System (ADS)

    Makiniemi, Matti; Kopola, Harri K.; Oikarinen, Kyosti; Herrala, Esko

    1995-02-01

    Since the diagnosis of the intradental blood supply is difficult in dental trauma, we have designed and built a new dental pulp vitalometer based on optical reflectance measurement and exploiting the different absorption spectra of haemoglobins. The device comprises light transmitters, a receiver, electronics and a PC. Pulsed light is transmitted along the fiber optic probe, which illuminates the tooth being tested. The same probe collects the reflected light from the tooth pulp and transfers the light to the receiver. The received signal is divided into AC and DC components and a data acquisition card reads these signals, performs an A/D conversion and writes the results in a text file. A reference plethysmogram signal from a finger is used to help in processing the measured dental signal. The computer program calculates an estimate for the oxygen saturation.

  15. Does removal of the original pulp tissue before autotransplantation influence ingrowth of new tissue in the pulp chamber?

    PubMed

    Laureys, Wim G M; Dermaut, Luc R; Cuvelier, Claude A; De Pauw, Guy A M

    2010-10-01

    In an attempt to extend the indication area for autotransplantation of vital teeth, two possibilities can be proposed: (i) The enlargement of the apical foramen, with the aim to facilitate revascularization and ingrowth of new tissue. The ingrowth of tissue will eliminate the need for endodontic treatment when mature teeth are transplanted and (ii) the cryopreservation of teeth in case they cannot be transplanted immediately to the receptor site. Teeth with an ideal stage of root formation can be cryopreserved to perform transplantation later. Although pulpcell cultures survive crypreservation in vitro, the pulp tissue cannot survive the cryopreservation procedures when it is kept inside the pulpchamber. Therefore, the pulp tissue has to be removed before cryopreservation. It has been demonstrated that revascularization and ingrowth of new tissue can occur in an empty pulp chamber (1). The aim of this study was to find out if revascularization and ingrowth of new pulp tissue is influenced by removal of the original pulp tissue before autotransplantation. Twenty nine single-rooted teeth from three adult beagle dogs were transplanted after resection of the root tip. One group of teeth (n = 14) had the pulp tissue removed before transplantation. The other group (n = 15) had the original pulp left in situ. The transplanted teeth were histologically analysed 90 days post-transplantation. In the group with the tissue left in situ, 12 teeth (80%) showed a pulp chamber totally filled or at least 1/3 to 2/3 filled with viable tissue. In the group with the pulp tissue removed, 11 teeth (79%) had no or little vital tissue in the pulp chamber. The necrotic masses that develop in the original pulp tissue immediately after transplantation are a possible stimulating factor in the repair process of the pulp. As a conclusion, it can be stated that in case of autotransplantation of teeth, it is advisable to leave the pulp tissue in situ to stimulate the revascularization and

  16. Surface and thermal enhancement of the cellulosic component of thermo mechanical pulp using a rapid method: Iodomethane modification.

    PubMed

    George, Michael; Mussone, Paolo G; Bressler, David C

    2016-05-20

    The feasibility of employing chemical methods for enhancement of cellulose-based materials is dependent on the availability, price, and green index of the modifying agent. This study details the use of iodomethane, an inexpensive organo halide, to increase the hydrophobicity of thermo mechanical (TMP) samples, which renders them better structural elements for composite materials. For this system, we studied the influence of various concentration of iodomethane, concentration of caustic, and reaction time. Infrared spectroscopy suggested reaction of the organo halide with the hydroxyl groups of cellulose and lignin components of TMP. Pulp samples treated for 4 h or at low caustic concentration showed the least improvements plausibly due to pulp degradation or poor pulp swelling, respectively. On the other hand, pulp treated at 3 h using high concentrations of caustic were characterized with surfaces that were more hydrophobic. Thus, this study outlines a fast and organic solvent-free (clean up) method that can be used to enhance pulp samples for composite applications. PMID:26917403

  17. Facilitating the enzymatic saccharification of pulped bamboo residues by degrading the remained xylan and lignin-carbohydrates complexes.

    PubMed

    Huang, Caoxing; He, Juan; Li, Xin; Min, Douyong; Yong, Qiang

    2015-09-01

    Kraft pulping was performed on bamboo residues and its impact on the chemical compositions and the enzymatic digestibility of the samples were investigated. To improve the digestibility of sample by degrading the xylan and lignin-carbohydrates complexes (LCCs), xylanase and α-L-arabinofuranosidase (AF) were supplemented with cellulase. The results showed more carbohydrates were remained in the samples pulped with low effective alkali (EA) charge, compared to conventional kraft pulping. When 120 IU/g xylanase and 15 IU/g AF were supplemented with 20 FPU/g cellulase, the xylan degradation yield of the sample pulped with 12% EA charge increased from 68.20% to 88.35%, resulting in an increased enzymatic saccharification efficiency from 58.98% to 83.23%. The amount of LCCs in this sample decreased from 8.63/100C9 to 2.99/100C9 after saccharification with these enzymes. The results indicated that degrading the remained xylan and LCCs in the pulp could improve its enzymatic digestibility. PMID:26080104

  18. Optical measurement of pulp quantity in a rotating disc refiner

    NASA Astrophysics Data System (ADS)

    Alahautala, Taito; Lassila, Erkki; Hernberg, Rolf; Härkönen, Esko; Vuorio, Petteri

    2004-11-01

    An optical method based on light extinction was used in measuring pulp quantity in the plate gap of a 10 MW thermomechanical pulping refiner for the first time. The relationship between pulp quantity and light extinction was determined by empirical laboratory experiments. The empirical relationship was then applied to interpret the image data obtained from field measurements. The results show the local distribution of pulp in the refiner plate gap for different rotor plate positions and refiner operation points. The maximum relative uncertainty in the measured pulp quantity was 50%. Relative pulp distributions were measured at higher accuracy. The measurements have influenced the development of a laser-based optical diagnostic method that can be applied to the quantitative visualization of technically demanding industrial processes.

  19. Wood Technology: Techniques, Processes, and Products

    ERIC Educational Resources Information Center

    Oatman, Olan

    1975-01-01

    Seven areas of wood technology illustrates applicable techniques, processes, and products for an industrial arts woodworking curriculum. They are: wood lamination; PEG (polyethylene glycol) diffusion processes; wood flour and/or particle molding; production product of industry; WPC (wood-plastic-composition) process; residential construction; and…

  20. FIRE INSURANCE AND WOOD SCHOOL BUILDINGS.

    ERIC Educational Resources Information Center

    PURCELL, FRANK X.

    A COMPARISON OF FIRE INSURANCE COSTS OF WOOD, MASONRY, STEEL AND CONCRETE STRUCTURES SHOWS FIRE INSURANCE PREMIMUMS ON WOOD STRUCTURES TEND TO BE HIGHER THAN PREMIUMS ON MASONRY, STEEL AND CONCRETE BUILDINGS, HOWEVER, THE INITIAL COST OF THE WOOD BUILDINGS IS LOWER. DATA SHOW THAT THE SAVINGS ACHIEVED IN THE INITIAL COST OF WOOD STRUCTURES OFFSET…

  1. Responding to Agenda 2020: A technology vision and research agenda for America`s forest, wood and paper industry

    SciTech Connect

    Lang, K.S.

    1995-03-01

    This document presents project summaries that demonstrate specific capabilities of interest to the forest, wood and paper industry in areas where PNL offers significant depth of experience or unique expertise. Though PNL possesses a wide range of capabilities across many of the technology-related issues identified by the industry, this document focuses on capabilities that meet the specific forest, wood and paper industry needs of the following research areas: forest inventory; human and environmental effects; energy and environmental tradeoffs; reduction of impacts of liquid effluent; solid wastes; removal of non-process elements in pulp and paper operations; life cycle assessment; and process measurement and controls. In addition, PNL can provide the forest, wood and paper industry with support in areas such as strategic and program planning, stakeholder communications and outreach, budget defense and quality metrics. These are services PNL provides directly to several programs within DOE.

  2. Degradation kinetics of the main carbohydrates in birch wood during hot water extraction in a batch reactor at elevated temperatures.

    PubMed

    Borrega, Marc; Nieminen, Kaarlo; Sixta, Herbert

    2011-11-01

    Hot water extraction of wood at elevated temperatures may be a suitable method to produce hemicellulose-lean pulps and to recover xylan-derived products from the water extract. In this study, water extractions of birch wood were conducted at temperatures between 180 and 240 °C in a batch reactor. Xylan was extensively removed, whereas cellulose was partly degraded only at temperatures above 180 °C. Under severe extraction conditions, acetic acid content in the water extract was higher than the corresponding amount of acetyl groups in wood. In addition to oligo- and monosaccharides, considerable amounts of furfural and 5-hydroxymethylfurfural (HMF) were recovered from the extracts. After reaching a maximum, the furfural yield remained constant with increasing extraction time. This maximum slightly decreased with increasing extraction temperature, suggesting the preferential formation of secondary degradation products from xylose. Kinetic models fitting experimental data are proposed to explain degradation and conversion reactions of xylan and glucan. PMID:21967712

  3. Immune defense mechanisms of the dental pulp.

    PubMed

    Jontell, M; Okiji, T; Dahlgren, U; Bergenholtz, G

    1998-01-01

    Defense reactions of the dentin/pulp complex involve a variety of biological systems, in which the immune system plays a pivotal role. The knowledge of the organization and function of pulpal immunocompetent cells has been sparse, but in recent years a significant body of information of immune mechanisms in general has provided a footing for substantial new knowledge of the immune mechanisms of the dental pulp. The identification of pulpal dendritic cells (DCs) has generated research activities which have led to a concept of how an antigenic challenge may evoke a pulpal inflammatory response. Although DCs are not able to identify foreign antigens specifically, they provide necessary signals to activate T-lymphocytes which in turn will orchestrate other immunocompetent cells to mount the local immune defense of the dental pulp. The purpose of this review is to accent the organization and function of pulpal DCs and other tissue and cellular components and to provide a basis for how they may interact to instigate pulpal defense mechanisms. PMID:9603235

  4. Mechanical behaviors of molded pulp material

    NASA Astrophysics Data System (ADS)

    Ji, Hongwei; Wang, Huaiwen; Chen, Jinlong

    2008-11-01

    Many mechanical phenomena of interest for web-like materials, such as molded pulp, take place at the micro-scale. A SEM (scanning electron microscope) with SHIMADZU electrohydraulic servo experimental system was employed to study the micro-scale mechanical behavior of molded pulp materials. Uniaxial tension tests of molded pulp specimens were carried out, resulting in the stress-strain curves. Experimental results indicated that the material is not only elasticplastic, but also emplastic. The surface morphology evolution of the tensile specimen was visually monitored during the process of loading, and some SEM micrographs were captured under different load levels. Full-field deformations over an area of 190x170 μm2 were obtained using the digital image correlation method. The higher strains occurred at the fibre fines zone or around voids whereas the lower strains were obviously found at long fibres, demonstrating that the strain distribution is obviously uneven. The reason may be due to the random orientation and the fraction of the fibres, and the presence of impurities and voids as well.

  5. The ecology of "fecal indicator" bacteria commonly found in pulp and paper mill water systems.

    PubMed

    Gauthier, F; Archibald, F

    2001-06-01

    Coliform bacteria have long been used to indicate fecal contamination of water and thus a health hazard. In this study, the in-mill water and external effluent treatment systems of seven typical Canadian pulp and paper mills were all shown to support the growth of numerous coliforms, especially Klebsiella Spp., Escherichia coli. Enterobacter spp., and Citrobacter spp. In all mills and most sampled locations, klebsiellas were the predominant coliforms. Although all but one of the mills had no sewage input and most disinfected their feed (input) water, all contained the most typical fecal indicator bacterium, E. coli. Many of the mill coliforms were classified as fecal coliforms by standard "MPN" and metabolic tests, but this was shown to be due to their thermotolerance, not their origin. Mill coliforms were shown not to be just simple transients from feedwater or furnish (wood), but to be continuously growing, especially in some of the primary clarifiers. Isolated mill coliforms grew very well on a sterilized raw combined mill effluent. The fecal streptococci (enterococci), alternative indicators of fecal health hazards, were common in all mills in the absence of sewage. Ten strains of E. coli isolated from four mills were all shown to be non-toxigenic strains of harmless serotypes. No salmonellas were found. Therefore, the use of total coliform, fecal coliform, enterococci, or E. coli counts as indicators of fecal contamination, and thus of health hazard in pulp and paper mill effluents or biosolids (sludges) known to be free of fecal input is invalid. PMID:11358300

  6. Characterisation of mechanical pulp fines from alkaline peroxide pulping of EFB

    NASA Astrophysics Data System (ADS)

    Kamaludin, Nurul Hasanah; Ghazali, Arniza; Daud, Wan Rosli Wan

    2012-09-01

    EFB (empty fruit bunch) was subjected to alkaline peroxide pulping for generation of fibrous mass as raw material for the making of pulp-based products. During refining, co-produced fines were collected by fractionation on square-mesh screens of 200-, 250-, 300- and 400- mesh sizes, placed at the refining discharge by order of increasing mesh. Each set of the produced paper was incorporated with 12% fines for microscopic analysis. It appears that sheared vessel elements and fibrils were predominant and they make up the mass rendering collapsibility of cell wall for good product formation. The study acknowledged the form of fines functioning as natural filler in pulp network and worthy of utilization for reduction of total suspended solid.

  7. Acid hydrolysis of cellulosic fibres: Comparison of bleached kraft pulp, dissolving pulps and cotton textile cellulose.

    PubMed

    Palme, Anna; Theliander, Hans; Brelid, Harald

    2016-01-20

    The behaviour of different cellulosic fibres during acid hydrolysis has been investigated and the levelling-off degree of polymerisation (LODP) has been determined. The study included a bleached kraft pulp (both never-dried and once-dried) and two dissolving pulps (once-dried). Additionally, cotton cellulose from new cotton sheets and sheets discarded after long-time use was studied. Experimental results from the investigation, together with results found in literature, imply that ultrastructural differences between different fibres affect their susceptibility towards acid hydrolysis. Drying of a bleached kraft pulp was found to enhance the rate of acid hydrolysis and also result in a decrease in LODP. This implies that the susceptibility of cellulosic fibres towards acid hydrolysis is affected by drying-induced stresses in the cellulose chains. In cotton cellulose, it was found that use and laundering gave a substantial loss in the degree of polymerisation (DP), but that the LODP was only marginally affected. PMID:26572472

  8. Pilot scale fermentation of Jerusalem artichoke tuber pulp mashes

    SciTech Connect

    Ziobro, G.C.; Williams, L.A.

    1983-01-01

    Processing and fermentation of Jerusalem artichoke (Helianthus tuberosus L.) tuber pulp mashes were successfully carried out at pilot scales of 60 gallons and 1000 gallons. Whole tubers were pulped mechanically into a thick mash and fermented, using commercially available Saccharomyces cerevisiae and selected strains of Kluyveromyces fragilis. EtOH fermentation yields ranging from 50-70% of theoretical maximum were obtained in 3-4 days. Several problems regarding the processing and direct fermentation of tuber pulp mashes are discussed.

  9. Bioceramic Materials and the Changing Concepts in Vital Pulp Therapy.

    PubMed

    Cao, Yangpei; Bogen, George; Lim, Jung; Shon, Won-Jun; Kang, Mo K

    2016-05-01

    Vital pulp therapy (VPT) is devised to preserve and maintain vitality of pulpally involved teeth challenged by a variety of intraoral conditions. Notable progress has been made in this field due to a better understanding of pulp physiology, improved clinical protocols and advanced bioceramic materials paired with adhesive technology. With focused case selection, conservative VPT can provide reliable treatment options for permanent teeth diagnosed with normal pulps or reversible pulpitis. PMID:27290822

  10. The ups and downs of the pulp and paper industry

    SciTech Connect

    McKenna, J.C.

    1998-12-31

    The ``Up`s and Down`s of the Pulp and Paper Industry`` deals with the design, fabrication, and installation elements of upflow and downflow bleach (retention) towers utilized in the Pulp and Paper industry. Fabrication processes for the shop and field components of these systems are reviewed. In addition, an overview of the advantages of Fiberglass Reinforced Plastics (FRP), considering the changing chemistries for pulp bleaching is presented, and a number of case histories are reviewed.

  11. Goddard Summer Interns: Danielle Wood

    NASA Video Gallery

    Profile of Goddard intern Danielle Wood. Danielle is interning at Goddard in the Innovative Partnerships Program and at NASA Headquarters in the Office of the Chief Technologist in the summer of 20...

  12. Histopathology of the pulp in primary incisors with deep dentinal caries.

    PubMed

    Eidelman, E; Ulmanksy, M; Michaeli, Y

    1992-01-01

    The purpose of this study was to assess the histological appearance of the pulp of human primary incisors extracted because of deep, unrestorable caries, and to determine how clinical pulp exposures affected the histological status of the pulp compared to nonexposures. Caries was removed carefully from all teeth after fixation; 24 incisors had pulp exposures, and 29 teeth had no pulp exposures. Histological examination showed normal pulps in 69% of the teeth without pulp exposures, compared to 33% of teeth with exposed pulps (P < 0.05). Microabscesses were observed in 33% of cases with pulp exposures, compared to 10% of cases without pulp exposures. In this study, 46 of 53 pulps remained vital in spite of the multiple and deep carious lesions. Teeth without pulp exposures were diagnosed in the treatable category in 20 of 26 cases. PMID:1303544

  13. In vitro antibacterial activity of different pulp capping materials

    PubMed Central

    Beltrami, Riccardo; Colombo, Marco; Ceci, Matteo; Dagna, Alberto; Chiesa, Marco

    2015-01-01

    Background Direct pulp capping involves the application of a dental material to seal communications between the exposed pulp and the oral cavity (mechanical and carious pulp exposures) in an attempt to act as a barrier, protect the dental pulp complex and preserve its vitality. The aim of this study was to evaluate and compare, by the agar disc diffusion test, the antimicrobial activity of six different pulp-capping materials: Dycal (Dentsply), Calcicur (Voco), Calcimol LC (Voco), TheraCal LC (Bisco), MTA Angelus (Angelus), Biodentine (Septodont). Material and Methods Streptococcus salivarius, Streptococcus sanguis and Streptococcus mutans strains were selected to evaluate the antimicrobial activity by the agar disc diffusion test of different pulp capping materials. Paper disks were impregnated whit each pulp capping materials and placed onto culture agar-plates pre-adsorbed with bacterial cells and further incubated for 24 h at 37°C. The growth inhibition zones around each pulp capping materials were recorded and compared for each bacterial strain. Results For the investigation of the antibacterial properties the ANOVA showed the presence of significant differences among the various materials. Tukey test showed that MTA-based materials induced lower growth inhibition zones. Conclusions MTA-based products show a discrete antibacterial activity varying from calcium hydroxide-based materials which present an higher antibacterial activity. Key words:Agar disc diffusion test, antimicrobial activity, calcium hydroxide, MTA, pulp capping materials. PMID:26644833

  14. Association between dental pulp stones and calcifying nanoparticles.

    PubMed

    Zeng, Jinfeng; Yang, Fang; Zhang, Wei; Gong, Qimei; Du, Yu; Ling, Junqi

    2011-01-01

    The etiology of dental pulp stones, one type of extraskeletal calcification disease, remains elusive to date. Calcifying nanoparticles (CNPs), formerly referred to as nanobacteria, were reported to be one etiological factor in a number of extraskeletal calcification diseases. We hypothesized that CNPs are involved in the calcification of the dental pulp tissue, and therefore investigated the link between CNPs and dental pulp stones. Sixty-five freshly collected dental pulp stones, each from a different patient, were analyzed. Thirteen of the pulp stones were examined for the existence of CNPs in situ by immunohistochemical staining (IHS), indirect immunofluorescence staining (IIFS), and transmission electron microscope (TEM). The remaining 52 pulp stones were used for isolation and cultivation of CNPs; the cultured CNPs were identified and confirmed via their shape and growth characteristics. Among the dental pulp stones examined in situ, 84.6% of the tissue samples staines positive for CNPs antigen by IHS; the corresponding rate by IIFS was 92.3 %. In 88.2% of the cultured samples, CNPs were isolated and cultivated successfully. The CNPs were visible under TEM as 200-400 nm diameter spherical particles surrounded by a compact crust. CNPs could be detected and isolated from a high percentage of dental pulp stones, suggesting that CNPs might play an important role in the calcification of dental pulp. PMID:21289988

  15. Pulp Fibroblasts Control Nerve Regeneration through Complement Activation.

    PubMed

    Chmilewsky, F; About, I; Chung, S-H

    2016-07-01

    Dentin-pulp regeneration is closely linked to the presence of nerve fibers in the pulp and to the healing mechanism by sprouting of the nerve fiber's terminal branches beneath the carious injury site. However, little is known about the initial mechanisms regulating this process in carious teeth. It has been recently demonstrated that the complement system activation, which is one of the first immune responses, contributes to tissue regeneration through the local production of anaphylatoxins such as C5a. While few pulp fibroblasts in intact teeth and in untreated fibroblast cultures express the C5a receptor (C5aR), here we show that all dental pulp fibroblasts, localized beneath the carious injury site, do express this receptor. This observation is consistent with our in vitro results, which showed expression of C5aR in lipoteichoic acid-stimulated pulp fibroblasts. The interaction of C5a, produced after complement synthesis and activation from pulp fibroblasts, with the C5aR of these cells mediated the local brain-derived neurotropic factor (BDNF) secretion. Overall, this activation guided the neuronal growth toward the lipoteichoic acid-stimulated fibroblasts. Thus, our findings highlight a new mechanism in one of the initial steps of the dentin-pulp regeneration process, linking pulp fibroblasts to the nerve sprouting through the complement system activation. This may provide a useful future therapeutic tool in targeting the fibroblasts in the dentin-pulp regeneration process. PMID:27053117

  16. LPS induces pulp progenitor cell recruitment via complement activation.

    PubMed

    Chmilewsky, F; Jeanneau, C; Laurent, P; About, I

    2015-01-01

    Complement system, a major component of the natural immunity, has been recently identified as an important mediator of the dentin-pulp regeneration process through STRO-1 pulp cell recruitment by the C5a active fragment. Moreover, it has been shown recently that under stimulation with lipoteichoic acid, a complex component of the Gram-positive bacteria cell wall, human pulp fibroblasts are able to synthesize all proteins required for complement activation. However, Gram-negative bacteria, which are also involved in tooth decay, are known as powerful activators of complement system and inflammation. Here, we investigated the role of Gram-negative bacteria-induced complement activation on the pulp progenitor cell recruitment using lipopolysaccharide (LPS), a major component of all Gram-negative bacteria. Our results show that incubating pulp fibroblasts with LPS induced membrane attack complex formation and C5a release in serum-free fibroblast cultures. The produced C5a binds to the pulp progenitor cells' membrane and induces their migration toward the LPS stimulation chamber, as revealed by the dynamic transwell migration assays. The inhibition of this migration by the C5aR-specific antagonist W54011 indicates that the pulp progenitor migration is mediated by the interaction between C5a and C5aR. Our findings demonstrate, for the first time, a direct interaction between the recruitment of progenitor pulp cells and the activation of complement system generated by pulp fibroblast stimulation with LPS. PMID:25359783

  17. Production and use of industrial wood and bark residues in the Tennessee Valley region, 1984

    SciTech Connect

    Not Available

    1986-08-01

    Forest products industries in the 201-county Tennessee Valley region produced 8.7 million tons (initial condition) of industrial wood and bark residues in 1984. In the 125-county Tennessee Valley watershed, 4.8 million tons of residues were produced. Use of these residues was similar for both areas (201 area - 87.2% and 125 area - 86.8%). These residues were used chiefly for pulp and industrial fuel. This report highlights changes in the production and use of plant by-products since 1975. Detailed information is presented by industry and county on the type, condition, amount, and use of residues produced. The information is designed for use by firms plannng expansions or new developements using wood and bark residues as a raw material. 7 refs., 4 figs., 6 tabs.

  18. Modelling inorganic biocide emission from treated wood in water.

    PubMed

    Tiruta-Barna, Ligia; Schiopu, Nicoleta

    2011-09-15

    The objective of this work is to develop a chemical model for explaining the leaching behaviour of inorganic biocides from treated wood. The standard leaching test XP CEN/TS14429 was applied to a commercial construction material made of treated Pinus sylvestris (Copper Boron Azole preservative). The experimental results were used for developing a chemical model under PHREEQC(®) (a geochemical software, with LLNL, MINTEQ data bases) by considering the released species detected in the eluates: main biocides Cu and B, other trace biocides (Cr and Zn), other elements like Ca, K, Cl, SO(4)(-2), dissolved organic matter (DOC). The model is based on chemical phenomena at liquid/solid interfaces (complexation, ion exchange and hydrolysis) and is satisfactory for the leaching behaviour representation. The simulation results confronted with the experiments confirmed the hypotheses of: (1) biocide fixation by surface complexation reactions with wood specific sites (carboxyl and phenol for Cu, Zn, Cr(III), aliphatic hydroxyl for B, ion exchange to a lesser extent) and (2) biocide mobilisation by extractives (DOC) coming from the wood. The maximum of Cu, Cr(III) and Zn fixation occurred at neutral pH (including the natural pH of wood), while B fixation was favoured at alkaline pH. PMID:21794983

  19. Tribology in secondary wood machining

    SciTech Connect

    Ko, P.L.; Hawthorne, H.M.; Andiappan, J.

    1998-07-01

    Secondary wood manufacturing covers a wide range of products from furniture, cabinets, doors and windows, to musical instruments. Many of these are now mass produced in sophisticated, high speed numerical controlled machines. The performance and the reliability of the tools are key to an efficient and economical manufacturing process as well as to the quality of the finished products. A program concerned with three aspects of tribology of wood machining, namely, tool wear, tool-wood friction characteristics and wood surface quality characterization, was set up in the Integrated Manufacturing Technologies Institute (IMTI) of the National Research Council of Canada. The studies include friction and wear mechanism identification and modeling, wear performance of surface-engineered tool materials, friction-induced vibration and cutting efficiency, and the influence of wear and friction on finished products. This research program underlines the importance of tribology in secondary wood manufacturing and at the same time adds new challenges to tribology research since wood is a complex, heterogeneous, material and its behavior during machining is highly sensitive to the surrounding environments and to the moisture content in the work piece.

  20. A Review of Polyphenolics in Oak Woods

    PubMed Central

    Zhang, Bo; Cai, Jian; Duan, Chang-Qing; Reeves, Malcolm J.; He, Fei

    2015-01-01

    Polyphenolics, which are ubiquitous in plants, currently are among the most studied phytochemicals because of their perceptible chemical properties and antioxidant activity. Oak barrels and their alternatives, which are widely used in winemaking nowadays, contribute polyphenolics to wines and are thought to play crucial roles in the development of wines during aging. This study summarizes the detailed information of polyphenolics in oak woods and their products by examining their structures and discussing their chemical reactions during wine aging. This paper evaluates the most recent developments in polyphenolic chemistry by summarizing their extraction, separation, and their identification by the use of chromatographic and spectral techniques. In addition, this paper also introduces polyphenol bioactive ingredients in other plant foods. PMID:25826529

  1. Cationic polyacrylamide enhancing cellulase treatment efficiency of hardwood kraft-based dissolving pulp.

    PubMed

    Wang, Qiang; Liu, Shanshan; Yang, Guihua; Chen, Jiachuan; Ni, Yonghao

    2015-05-01

    Cellulase treatment for decreasing viscosity and increasing Fock reactivity of dissolving pulp is a promising approach to reduce the use of toxic chemicals, such as hypochlorite in the dissolving pulp manufacturing process in the industry. Improving the cellulase treatment efficiency during the process is of practical interest. In the present study, the concept of using cationic polyacrylamide (CPAM) to enhance the cellulase treatment efficiency was demonstrated. This was mainly attributed to the increased cellulase adsorption onto cellulose fibers based on the patching/bridging mechanism. Results showed that the cellulase adsorption was increased by about 20% with the addition of 250 ppm of CPAM under the same conditions as those of the control. It was found that the viscosity decrease and Fock reactivity increase for the cellulase treatment was enhanced from using CPAM. The CPAM-assisted cellulase treatment concept may provide a practical alternative to the present hypochlorite-based technology for viscosity control in the industry. PMID:25710682

  2. Effect of rotation, site, and clone on the chemical composition of Populus hybrids

    SciTech Connect

    Blanckenhorn, P.R.; Bowersox, T.W.; Kuklewski, K.M.; Stimely, S.L.

    1985-01-01

    Chemical content values were determined for three Populus clones grown on two dissimilar sites by component (wood, bark, and wood/bark specimens), tissue age (1-, 2- and 4-year-old), and rotation. The chemical content values obtained included extractives, holocellulose, ..alpha..-cellulose, and lignin. In general, analysis of the data for the wood, bark, and wood/bark specimens indicated that: 1) wood was high in holocellulose and ..alpha..-cellulose content compared to bark, 2) bark was high in lignin and extractive content values compared to wood, and 3) wood/bark chemical content values were between the values for the wood and bark specimens. The chemical content data were analyzed to identify: 1) significant differences between rotations by component (wood, bark and wood/bark) for a given age, clone, and site, and 2) significant differences between sites for four-year-old wood, bark and wood/bark specimens of a given rotation, and clone. Statistical analyses indicated that significant differences existed among clones, sites, ages, and rotations. Within the wood, bark and wood/bark specimens, tissue age, rotation, and site influenced the chemical content values more than the parentage. Potential chemical yields derived from the three Populus hybrid clones investigated will depend on component, age, rotation, and site with limited parentage effects.

  3. The nature of the MDI/wood bond

    SciTech Connect

    Marcinko, J.J.; Phanopoulos, C.; Newman, W.H.

    1995-12-01

    Polymeric diphenylmethane diisocyanate (pMDI) binders have been used in the wood composite industry for 20 years. Almost one half of the oriented strand board (OSB) manufactures in North America are taking advantage of its processing speed and superior board performance. MDI`s current use in Strandboard, MDF (medium density fiber board), LVL (laminated veneer lumber), Plywood, and Particleboard is wide spread. A fundamental understanding of the role of MIDI as a binder in these complex composites is essential for further processing optimization. Experimental data is presented which investigates the nature of the chemical bonding in wood composites. Solid state nuclear magnetic resonance (NMR) data is combined with data from thermal analysis and fluorescence microscopy to investigate the chemistry, penetration, and morphology of the isocyanate/wood interphase. Structure property relationships are developed and related to composite performance. The study contrasts isocyanate and phenol formaldehyde binder systems.

  4. Effects of copper amine treatments on mechanical, biological and surface/interphase properties of poly (vinyl chloride)/wood composites

    NASA Astrophysics Data System (ADS)

    Jiang, Haihong

    2005-11-01

    The copper ethanolamine (CuEA) complex was used as a wood surface modifier and a coupling agent for wood-PVC composites. Mechanical properties of composites, such as unnotched impact strength, flexural strength and flexural toughness, were significantly increased, and fungal decay weight loss was dramatically decreased by wood surface copper amine treatments. It is evident that copper amine was a very effective coupling agent and decay inhibitor for PVC/wood flour composites, especially in high wood flour loading level. A DSC study showed that the heat capacity differences (DeltaCp) of composites before and after PVC glass transition were reduced by adding wood particles. A DMA study revealed that the movements of PVC chain segments during glass transition were limited and obstructed by the presence of wood molecule chains. This restriction effect became stronger by increasing wood flour content and by using Cu-treated wood flour. Wood flour particles acted as "physical cross-linking points" inside the PVC matrix, resulting in the absence of the rubbery plateau of PVC and higher E', E'' above Tg, and smaller tan delta peaks. Enhanced mechanical performances were attributed to the improved wetting condition between PVC melts and wood surfaces, and the formation of a stronger interphase strengthened by chemical interactions between Cu-treated wood flour and the PVC matrix. Contact angles of PVC solution drops on Cu-treated wood surfaces were decreased dramatically compared to those on the untreated surfaces. Acid-base (polar), gammaAB, electron-acceptor (acid) (gamma +), electron-donor (base) (gamma-) surface energy components and the total surface energies increased after wood surface Cu-treatments, indicating a strong tendency toward acid-base or polar interactions. Improved interphase and interfacial adhesion were further confirmed by measuring interfacial shear strength between wood and the PVC matrix.

  5. Wood typification by Venturi easy ambient sonic spray ionization mass spectrometry: the case of the endangered Mahogany tree.

    PubMed

    Cabral, Elaine C; Simas, Rosineide C; Santos, Vanessa G; Queiroga, Carmen L; da Cunha, Valnei S; de Sá, Gilberto F; Daroda, Romeu J; Eberlin, Marcos N

    2012-01-01

    Venturi easy ambient sonic spray ionization mass spectrometry in both its liquid (V(L) -EASI-MS) and solid sample modes (V(S) -EASI-MS) is shown to provide nearly immediate and secure typification of woods, as demonstrated for Mahogany, an endangered and most valuable type of tropical wood. This reddish wood displays unique phytochemical markers (phragmalin-type limonoids) which are rapidly detected from the wood surface by V(S) -EASI-MS or from a simple methanol extract of a tiny wood chip by V(L) -EASI-MS. Unique profiles were obtained for Mahogany (Swietenia macrophylla) whereas genuine samples of six other similar types of woods, which are commonly falsified by artificial coloring and commercialized as Mahogany, display also typical but dissimilar pythochemical profiles as compared to that of the authentic wood. Variable and atypical chemical profiles were observed for artificially colored woods. Secure chemical characterization via V(S) -EASI-MS or V(s) -EASI-MS fingerprints of Mahogany and other types of woods with similar appearance should help to control the illegal logging and trade of this and other endangered woods and their falsification, and to create certified standards. PMID:22282083

  6. Activity-guided identification of acetogenins as novel lipophilic antioxidants present in avocado pulp (Persea americana).

    PubMed

    Rodríguez-Sánchez, Dariana; Silva-Platas, Christian; Rojo, Rocío P; García, Noemí; Cisneros-Zevallos, Luis; García-Rivas, Gerardo; Hernández-Brenes, Carmen

    2013-12-30

    Avocado fruit is a rich source of health-related lipophilic phytochemicals such as monounsaturated fatty acids, tocopherols, carotenes, acetogenins and sterols. However, limited information is available on the contribution of specific phytochemicals to the overall antioxidant capacity (AOC) of the fruit. Centrifugal partition chromatography was used as fractionation tool, guided by an in vitro chemical assay of oxygen radical absorbance capacity (ORAC). Subsequent experiments focused on isolation and characterization of the chemical nature of the main contributors to lipophilic AOC of avocado pulp. ORAC values obtained for acetogenins were contrasted with results from an isolated kidney mitochondria membrane lipid peroxidation bioassay. The present study established that lipophilic AOC of the pulp was significantly higher than its hydrophilic AOC. Our results confirmed the presence of acetogenins in the fractions with highest lipophilic AOC, and for the first time linked them as contributors to lipophilic-ORAC values. Further HPLC-PDA/MS-TOF analysis led to structural elucidation of two novel acetogenins, not previously reported as present in avocado pulp, along with five already known related-compounds. Antioxidant properties observed for avocado pulp acetogenins by the ORAC assay suggested that, in the presence of an emulsifying agent, acetogenins could serve as novel lipophilic antioxidants in a food matrix. Results from isolated mitochondria lipid peroxidation bioassay, indicated that L-ORAC values which may have relevance for food matrix applications, should not be interpreted to have a direct relevance in health-related claims, compounds need to be evaluated considering the complexity of biological systems. PMID:24211333

  7. A new shock wave assisted wood preservative injection system

    NASA Astrophysics Data System (ADS)

    Rao, K. S.; Ravikumar, G.; Lai, Ram; Jagadeesh, G.

    Preservative treatment of many tropical hard woods and bamboo pose severe problem. A number of wood preservatives (chemical formulations toxic to wood decay/ destroying organisms like fungi, wood destroying termites, marine borers etc.) and wood impregnating techniques are currently in use for improving bio resistance of timber and bamboo and thereby enhancing service life for different end uses. How ever, some species of tropical hardwoods and many species of bamboo are difficult to treat, posing technical problems. In this paper we report preliminary results of treatment of bamboo with a novel Shockwave assisted injection treatment. Samples (30×2.5×1.00 cm) of an Indian species of bamboo Dendrocalamus strictus prepared from defect free culms of dry bamboo are placed in the driven section of a vertical shock tube filled with the 4Coppepr-Chrome-Arsenic(CCA) preservative solution.The bamboo samples are subjected to repeated shock wave loading (3 shots) with typical over pressures of 30 bar. The results from the study indicate excellent penetration and retention of CCA preservative in bamboo samples. The method itself is much faster compared to the conventional methods like pressure treatment or hot and cold process.

  8. Problems in Pulps: A Study of Special Collections in Pulp Magazines.

    ERIC Educational Resources Information Center

    Tuttle, George

    Heads of special collections of pulp magazines, the medium for popular fiction prior to the introduction of mass market paperbacks in 1939, were surveyed to help analyze and address the problems facing these collections. A survey mailed to special collections administrators gathered background information from the four largest collections…

  9. Robert Williams Wood: pioneer of invisible light.

    PubMed

    Sharma, Shruti; Sharma, Amit

    2016-03-01

    The Wood's lamp aids in the diagnosis of multiple infectious, inflammatory and neoplastic dermatologic conditions. Although the Wood's lamp has many applications, which have improved both the diagnosis and management of disease, the man credited for its invention is relatively unknown in medicine. Robert Williams Wood, a prominent physicist of the early 20th century, is credited for the invention of the Wood's lamp. Wood was the father of infrared and ultraviolet photography and made significant contributions to other areas in optics and spectroscopy. Wood's work encompassed the formative years of American Physics; he published over 200 original papers over his lifetime. A few years after the invention of the Wood's lamp for ultraviolet photography, physicians in Europe adopted the Wood's lamp for dermatologic applications. Wood's lamp remains popular in clinics globally, given its ease of use and ability to improve diagnostic precision. PMID:26752503

  10. Acoustic and adsorption properties of submerged wood

    NASA Astrophysics Data System (ADS)

    Hilde, Calvin Patrick

    Wood is a common material for the manufacture of many products. Submerged wood, in particular, is used in niche markets, such as the creation of musical instruments. An initial study performed on submerged wood from Ootsa Lake, British Columbia, provided results that showed that the wood was not suitable for musical instruments. This thesis re-examined the submerged wood samples. After allowing the wood to age unabated in a laboratory setting, the wood was retested under the hypothesis that the physical acoustic characteristics would improve. It was shown, however, that the acoustic properties became less adequate after being left to sit. The adsorption properties of the submerged wood were examined to show that the submerged wood had a larger accessible area of wood than that of control wood samples. This implied a lower amount of crystalline area within the submerged wood. From the combined adsorption and acoustic data for the submerged wood, relationships between the moisture content and speed of sound were created and combined with previous research to create a proposed model to describe how the speed of sound varies with temperature, moisture content and the moisture content corresponding to complete hydration of sorption sites within the wood.

  11. Dioxin effects on wood duck (Aix sponsa) embryos from sites near paper mills

    SciTech Connect

    Beeman, D.K.; Melancon, M.J.; Fleming, W.J.

    1994-12-31

    Biological and biochemical variables were studied in wood duck embryos from four dioxin-contaminated sites near paper mills in the Southeastern United States and three reference sites. Sites were selected based on a history of dioxin contamination in both sediments and fish. In addition, wood duck embryos collected downstream from an Arkansas Superfund site with demonstrated dioxin-induced reproductive impairment served as positive controls. Whole clutches of eggs were collected from the wild after fifteen days of incubation and mechanically incubated. Two embryos per clutch were sacrificed at pipping and liver monooxygenase activities (BROD, EROD and MROD) were quantified. Hatching success was determined for the remainder of the nest. Preliminary results indicate no difference in monooxygenase activities across sites even though the authors have previously demonstrated induction of monooxygenase activity in wood duck embryos in laboratory studies. In addition, there were no differences in weight at pipping, liver weight and liver weight to body weight ratios. No differences were seen in hatching success or weight at hatch nor were there any gross morphological abnormalities. This may indicate that exposure of wood ducks nesting near these pulp paper mills is below those which cause elevated monooxygenase activities and reproductive impairment.

  12. PDADMAC as a flocculant for lignosulfonate of NSSC pulping process.

    PubMed

    Oveissi, Farshad; Sitter, Thomas; Fatehi, Pedram

    2016-05-01

    The spent liquor (SL) of neutral sulfite semi-chemical (NSSC) pulping process contains about 8 wt% lignocelluloses that can be extracted and used in the production of value-added materials. In this work, a flocculation process followed by centrifugation was considered for isolating lignosulfonate and hemicelluloses from SL. It was observed that, by adding 20 mg/g of polydiallyldimethylammuniom chloride (PDADMAC) with 100,000-200,000 g/mol molecular weight to SL, 45% of lignosulfonate and 39% of hemicelluloses were removed at 30°C. The lignocellulose removal was more efficient for the dual flocculation system of low and high molecular weights PDADMAC than for individual PDADMAC systems. Overall, 49% of lignosulfonate, 47% of hemicelluloses and 97% of turbidity were removed from SL from the dual system when 10 mg/g low molecular weight PDADMAC and 10 mg/g high molecular weight PDADMAC were added to the SL at 30°C, subsequently. The thermogravimetric analysis (TGA) of generated flocs showed that all samples had similar thermal behaviour and 13-16 wt% of flocs remained as ash after burning at 700°C in nitrogen. As the flocs are made of lignocellulosic materials and they are thermally stable, they could be used as fillers in paper board production. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:686-691, 2016. PMID:26914393

  13. Aetiology, classification and pathogenesis of pulp and periapical disease.

    PubMed

    López-Marcos, Joaquín F

    2004-01-01

    At present, the majority of the treatments that are performed in the clinic are due to disease entities involving the dental pulp and periapex. Dental pulp is a richly vascularized and innervated tissue, enclosed by surrounding tissues that are incapable of expanding, such as dentin. It has terminal blood flow and small-gauge circulatory access the periapex. All of these characteristics severely constrain the defensive capacity of the pulp tissue when faced with the different aggressions it may be subjected to. Pulp tissue can also be affected by a retrograde infection, arising from the secondary canaliculi, from the periodontal ligament or from the apex during the course of periodontitis. Due to the fact that periapical disease is almost inevitably preceded by pulp disease, we shall begin by describing the causes of pulp disease and will then proceed to a discussion of the causes of periapical disease. The course of illness and classification of these pathological entities will depend on the aetiology involved. We will analyse pulp necrosis and pulp degeneration that are capable of triggering reversible apical periodontitis or irreversible apical periodontitis. PMID:15580137

  14. Influence of moderate to severe chronic periodontitis on dental pulp

    PubMed Central

    Fatemi, K; Disfani, R; Zare, R; Moeintaghavi, A; Ali, Saadat A.; Boostani, H. R

    2012-01-01

    Background: The relationship between periodontal disease and dental pulp changes is controversial and has been debated for many years. This human study was performed to evaluate the possible effects of moderate to advanced periodontal disease on the different aspect of dental pulp structure. Materials and Methods: Twenty hopeless permanent teeth were extracted from systemically healthy adults because of moderate to advanced chronic periodontitis, with a bone loss of >6 mm and a mobility of grade 2 or 3. Upon extraction, the apical 2 to 3 mm of the roots were immediately sectioned. Four to five sections were mounted on each slide, and every third slide was stained with hematoxylin and eosin. The specimens were histologically processed and examined by an oral pathologist. Results: Non-inflamed pulp, with partial or complete necrosis in some sections and several non-necrotic sections, was found in only 6.3% of teeth. Most teeth (58.3%) displayed edematous pulps. Slightly fibrotic pulps were seen in 52.1% of sections. Odontoblastic integrity was seen in 31.3% of teeth. Most teeth (77.1%) displayed no pulp stones. In 43.8% of teeth, the pulp vessels displayed dilatation. Conclusions: Moderate to advanced periodontal disease can affect the dental pulp. Careful consideration of diagnostic and treatment planing in patients with endodontic-periodontal involvement is therefore recommended. PMID:23493524

  15. TOXICITY OF PULP AND PAPER MILL EFFLUENT, A LITERATURE REVIEW

    EPA Science Inventory

    The review of pulp and paper mill effluents considers the need for additional toxicity data to insure effective effluent regulation. Effluent characteristics and problems of toxicity testing particular to pulp and paper mill effluents are discussed; however, the emphasis is on to...

  16. Corvidae feather pulp and West Nile virus detection

    USGS Publications Warehouse

    Docherty, D.E.; Romaine Long, R.; Griffin, Katie M.; Saito, E.K.

    2004-01-01

    We evaluated cloacal swab, vascular pulp of flight feather, and kidney and spleen pool samples from carcasses of members of the family Corvidae as sources of West Nile virus (WNV). The cloacal swab, kidney and spleen pool, and feather pulp were the source of WNV in 38%, 43%, and 77%, respectively, of the carcasses.

  17. Axonal Degeneration in Dental Pulp Precedes Human Primary Teeth Exfoliation.

    PubMed

    Suzuki, K; Lovera, M; Schmachtenberg, O; Couve, E

    2015-10-01

    The dental pulp in human primary teeth is densely innervated by a plethora of nerve endings at the coronal pulp-dentin interface. This study analyzed how the physiological root resorption (PRR) process affects dental pulp innervation before exfoliation of primary teeth. Forty-four primary canine teeth, classified into 3 defined PRR stages (early, middle, and advanced) were fixed and demineralized. Longitudinal cryosections of each tooth were stained for immunohistochemical and quantitative analysis of dental pulp nerve fibers and associated components with confocal and electron microscopy. During PRR, axonal degeneration was prominent and progressive in a Wallerian-like scheme, comprising nerve fiber bundles and nerve endings within the coronal and root pulp. Neurofilament fragmentation increased significantly during PRR progression and was accompanied by myelin degradation and a progressive loss of myelinated axons. Myelin sheath degradation involved activation of autophagic activity by Schwann cells to remove myelin debris. These cells expressed a sequence of responses comprising dedifferentiation, proliferative activity, GAP-43 overexpression, and Büngner band formation. During the advanced PRR stage, increased immune cell recruitment within the dental pulp and major histocompatibility complex (MHC) class II upregulation by Schwann cells characterized an inflammatory condition associated with the denervation process in preexfoliative primary teeth. The ensuing loss of dental pulp axons is likely to be responsible for the progressive reduction of sensory function of the dental pulp during preexfoliative stages. PMID:26149320

  18. 21 CFR 872.1730 - Electrode gel for pulp testers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Electrode gel for pulp testers. 872.1730 Section 872.1730 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1730 Electrode gel for pulp testers....

  19. 21 CFR 872.1730 - Electrode gel for pulp testers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrode gel for pulp testers. 872.1730 Section 872.1730 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1730 Electrode gel for pulp testers....

  20. 21 CFR 872.1730 - Electrode gel for pulp testers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electrode gel for pulp testers. 872.1730 Section 872.1730 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1730 Electrode gel for pulp testers....