Your search resulted in 352 documents. Displaying 25 entries per page.
A Green and Novel Technology for Recovering Copper and Wood from Treated Wood Waste – Part II: Optimization, copper metal recovery, and process design
2017 - IRG/WP 17-50326
The US consumes 70 million pounds of copper and produces 580 million cubic feet treated wood annually. The EPA disallows burning and reusing treated wood waste due to health/environmental concerns. Vast quantities of copper and wood are landfilled. Two safe and low cost extraction systems, citric acid and ammonium citrate, were identified in Part I of this study. In Part II of the study, effects of extraction conditions such as time, temperature, and equilibrium copper concentration were determined. More than 95% of copper was removed either at ambient temperature for 8 hours or at 40oC for 4 hours. The resulting solution was used in consecutive extractions with new batches of wood until copper reached its rate limiting concentration. The study demonstrated that copper in the extraction solutions could be electroplated onto various metal surfaces, thus efficiently recovered. This process regenerated aqueous solutions to be reused for future extraction. A chemical/engineering process was developed with this study for extracting copper from treated wood wastes, recovering copper from extraction solutions by electroplating, and cyclic use of regenerated aqueous solution. This green and novel technology can keep copper and wood from the landfill and bring tremendous environmental, economic, and social benefits.
S Chen, R Patel
Wood kiln drying. Simple process of material treament or soft method of preservation? (Le séchage arificiel du bois. Simple opération de traitement du metériau ou méthode douce de préservation?)
1993 - IRG/WP 93-50001-14
Among the processes enabling to extend wood durability, kiln drying can be considered as a treatment and soft preservation method. Dry woods are naturally durable provided they are not subject to important retaking of the moisture. Drying thanks to the application of temperatures from 50 to120°C enable to execute a thermic treatment which kills grubs and mushrooms to ensure a sterilization that can be durable if wood doesn't retake water. Noumerous connections and analogies between drying process and the preservation one enable to conclude that kiln drying is a real operation of wood treatment either curative or to a smaller extent preventive.
Controlled envelope treatments of Pinus sapwood, achieved by modifications to impregnation process and carrier solvents
2003 - IRG/WP 03-40258
Specimens of slash pine or radiata pine were treated to a target retention of 0.02% m/m permethrin with conventional light organic solvent fluids or with oil-modified fluids (Tanalith® T). Best achievable envelopes from LOSP fluids were poorly controlled, penetrating not only the target outer 0-5 mm zone (mean 0.019%, RSD 28%), but also breaking through into the 5-10 mm zone (mean 0.013%, RSD 37%) and further into the >10 mm zone (mean 0.011%, RSD 52%). With the oil-modified fluids, the target 0-5 mm zone received a mean retention of 0.024% (RSD 30%), with 0.003% (RSD 44%) in the 5-10 mm zone and <0.002% the >10 mm zone. This tight control of toxicant distribution facilitates economical termite control.
M J Kennedy, P R S Cobham
Scale-up of a chemical process for copper-based preservative-treated wood wastes recycling
2012 - IRG/WP 12-50286
In recent years, the development of appropriate wood waste disposal options has been encouraged by severe regulations and expensive fees associated with wastes landfilling or burning. An efficient and economically attractive leaching process was developed at laboratory scale (200 mL) for CCA-, ACQ- and CA-treated wood wastes recycling. This leaching process consisted of three leaching steps of 2 hours each, at 75°C with a sulfuric acid concentration at 9.8 g/L followed by three water-rinsing steps. The objective of this study was to investigate a possible application of this process to various mixtures of copper-based preservatives-treated wood wastes at pilot scale (80 L). The mixture of copper-based preservative-treated wood wastes was defined in order to represent wood waste stream evolution in the next decades. At the end of the leaching process, more than 98% of arsenic, 89% of chromium and 99% of copper were removed from a mixture of treated wood. Metal concentrations of the effluents produced during leaching steps were higher than regulations for effluents discharge in urban sewer. Leachate treatment by precipitation-coagulation was highly efficient and achieved more than 98% metal removal. The remaining arsenic, chromium and copper concentrations of the final effluents satisfied Quebec City municipal effluent discharge regulations. Chemicals consumption (sulfuric acid, ferric chloride, sodium hydroxide) depends of the mixture composition of treated wood. Remediation costs (total direct, indirect and general costs) ranged from $140 to $180 per metric ton of treated wood (ttw) depending on percentage of CCA-treated wood in the mixture. The use of wood residue for energy production represents an operating income estimated at $155/ttw (considering an energetic value of $13 per GJ).
L Coudert, L Gastonguay, J F Blais, G Mercier, P Cooper, P Morris, A Janin, N Reynier
How intraspecific radial variability of the European Oak’s may influence mild pyrolysis process and durability of the material
2016 - IRG/WP 16-40725
Last decades wood is promoted as building material. Unprotected wood exposed to outdoor conditions undergoes a variety of degradation induced essentially by fungi attacks. Heat treatment of wood by mild pyrolysis (180°C T 240°C under inert atmosphere) is a preservation process with a weak environmental impact, and therefore, is viewed as an interesting alternative to the chemical impregnation methods. It is generally well recognized that final properties of thermally modified wood like decay resistance, dimensional stability, mechanical properties or color depend on wood species but also and heat treatment process and treatment conditions like time and temperature. However, in spite of different studies describing the effect of inter specific variability on wood thermal degradation, no study describes the effect of intraspecific variability of wood on thermo modification processes. As wood physical properties as well as chemical composition can vary between and within species, between stands and even within tree, we tested the effect of radial position of European oak wood (Quercus petraea Liebl.) on its thermal stability. Samples of heartwood, sapwood, juvenile wood, earlywood or latewood taken from the radii of 2 trees were ground to fine sawdust subjected to thermogravimetric analysis (TGA) at 220°C for 2 hours using the same heating program. At the same time, holocellulose, cellulose and extractives as well as extracted heartwood and sapwood were also subjected to TGA using the same procedure. Results indicated that heartwood was more sensitive to heat than sapwood, the inner side of heartwood being more sensitive than the outer side. Differences were also noticed between native and extracted wood, the latter ones being less sensitive to thermal degradation. These results were consistent with the stability of each wood cell wall component indicating that extractives were more susceptible to thermal degradation than holocellulose, holocellulose being more susceptible than cellulose. At the ring level, earlywood was shown to be slightly more sensitive to thermal degradation than latewood. It was therefore concluded that since wood radial position and the earlywood/latewood ratio determine the thermal stability of oak wood, the quality and the homogeneity of initial wood boards should be carefully controlled to avoid heterogeneity in the treatment leading to end products with different properties and quality.
J Hamada, A Pétrissans, F Mothe, M Pétrissans, P Gérardin
Chemical, physical-mechanical characterization and durability of thermally modified beech and ash wood by thermo-vacuum process (Termovuoto)
2016 - IRG/WP 16-40758
The paper illustrates part of the results from the CIP Eco-innovation project “Thermo-vacuum: new process for new generation of thermally modified wood”. The project is part of the 7th Framework Programme for European Research and Technological Development, and thermo-vacuum modified wood is already on the European market. The project was selected by the European Commission, EASME Agency, as "Best of Eco-innovation: project success stories", May 2015, Barcelona. Temovuoto timber is already presented on the European market.
M Jebrane, I Cuccui, O Allegretti, N Terziev
Biological screening assays of wood samples treated with creosote plus chemical additives exposed to Limnoria tripunctata
1980 - IRG/WP 408
Laboratory methods for exposure of treated wood coupons to Limnoria tripunctata are described. Chemical additions to creosote were screened using this method. Three pesticides, Endrin, Kepone, and Malathion proved particularly effective. The addition of varying percentages of naphthalene to creosote using several treatment methods are currently being assayed. Results to date show that the coupons treated by the empty cell method have better performance than those prepared by the toluene dilution method. The naphthalene coupons treated by the full cell method show no attack after six months' exposure.
B R Richards, D A Webb
The effect of certain wood extractives on the growth of marine micro-organisms
1977 - IRG/WP 438
S E J Furtado, E B G Jones, J D Bultman
Pinus and Eucalyptus fenceposts treated with creosote and solvex tar by hot and cold open-tank process
1987 - IRG/WP 3455
A comparative study of the behaviour of two different wood preservatives, creosote and solvex-tar, was made, using two wood species, Pinus pinaster Ait and Eucalyptus globulus Labill, by the hot and cold open-tank process. Results showed that the creosote behaved better in relation with the uniformity of its distribution in wood. On the other hand, better results were obtained on Pinus for both preservatives.
M V Baonza Merino
Comparison of cubic and plug samples for preparation and data assembly in permeability study
2000 - IRG/WP 00-20197
In order to determine if plug experimental samples (PES: 30 x 15 mm2 diameter) could be used for inspection of wood permeability characteristics, radial and longitudinal flow directions were prepared according to either PES or cubic experimental samples (CES: 100 x 20 x 20 mm3) from the sapwood zone of Sitka spruce and treated by tanalith-C according to full-cell process. Results from the two preparation techniques agreed in the test to determine the mean percentage of void volume filled by liquid both radially and longitudinally, while the preparation process (i.e. machining, sealing, etc.) of the experimental samples and the period of the data collection was quite longer in CES than that for PES in either flow direction.
Results of chemical analyses in the field of wood preservation in the Bundesanstalt für Materialprüfung
1973 - IRG/WP 321
The results of qualitative and quantitative chemical analyses of wood preservatives are often the basis for evaluating the various works in the field of wood preservation. In the past 10 to 15 years a number of such works was carried out in the Bundesanstalt fur Materialprüfung, Berlin-Dahlem, dealing with the identification and effectiveness of wood preservatives and with methods of wood preservation. Fundamental realisations were made which will be summarised below. It seems advisable to differentiate between inorganic and organic chemical wood preservatives and methods of analyses. These are two distinct fields which differ also with regard to the analytical techniques applied.
H J Petrowitz
The decay resistance of chemically modified aspen composites to the white rot fungus Coriolus versicolor (L.) Quelet
1998 - IRG/WP 98-40122
Chemical modification of Aspen wood (Populus tremula L.) in the form of solid wood, veneers and sawdust was undertaken by a two step procedure consisting of esterification with maleic anhydride (MA) and subsequent oligoesterification with MA and glycidyl methacrylate (GMA) or allyl glycidyl ether (AGE). Modified wood was thermoplastic and was thermally formed by hot-pressing to produce veneer or solid wood samples with smooth glossy surfaces, while plastic-like wafers were obtained by hotpressing modified sawdust. Chemical modification alone was shown to enhance the biological resistance of Aspen to decay by Coriolus versicolor. In addition, hot-pressing enhanced decay resistance of both unmodified wood and esterified wood veneer samples, although no improvement was found by hot pressing oligoesterified wood. The most effective treatment for the improvement of decay resistance was chemical modification of the sawdust in conjunction with hot-pressing. A microscopic examination of chemically modified and control samples following exposure to the fungus showed more extensive colonisation and decay in untreated, unpressed samples.
M C Timar, A J Pitman, M D Mihai
The use of pressure cycling to improve heartwood penetration in Pinus radiata (D. Don)
1995 - IRG/WP 95-40050
This study investigates the effect of cycling pressure on the treatability of radiata pine heartwood. The results indicate that liquid penetration into the heartwood is affected by the preconditioning method used and pressure treatment time. There is no significant improvement in the penetration of Pinus radiata (D. Don) heartwood when a cycling or pulsation process is used.
P R S Cobham, P Vinden
Protocol for evaluation and approving new wood preservative
1985 - IRG/WP 2159
M E Hedley, J A Butcher
Wood furfurylation process and properties of furfurylated wood
2004 - IRG/WP 04-40289
The first processes for “furfurylation” of wood (wood modification with furfuryl alcohol) were developed several decades ago. Furfuryl alcohol is a renewable chemical since it is derived from furfural, which is produced from hydrolysed biomass waste. Over the last decade modernised processes for furfurylation of wood have been developed. These new processes are based on new catalytic systems and process additives. Two main processes for production of furfurylated wood have been developed for WPT (Wood Polymer Technology ASA) by the authors – Kebony 100 for high modification levels of hardwoods and VisorWood for lower modification levels of pine. Commercial production according to the Kebony process has been running since August 2000, mainly for flooring. A small Kebony production plant is now in operation in Lithuania. A larger Kebony/VisorWood production plant started up in September 2003 in Porsgrunn, Norway. Several new plants operating according to the VisorWood process, each with an annual capacity of 10 000 m³ or more, are under construction. The properties of furfurylated wood depend on the retention of grafted/polymerised furfuryl alcohol (PFA) in the wood. At high modification levels (high retention of PFA) the enhancement of a wide variety of properties are achieved: an exceptional hardness increase, exceptional resistance to microbial decay and insect attack, high resistance to chemical degradation, increase in MOR & MOE, and high dimensional stability. At lower modification levels many property enhancements also occur, however to slightly lower extent. Notable are resistance to microbial decay and insect attack, increase in MOR & MOE, and relatively high dimensional stability.
M Westin, S Lande, M Schneider
Chemical compounds from Eperua falcata and Eperua grandiflora heartwood and their biological activities against wood destroying fungus (Coriolus versicolor)
2005 - IRG/WP 05-30373
The chemistry analysis of the compounds present in dichloromethane and ethanolic fraction as well as bioassays enables to understand the durability differences of Eperua falcata and Eperua grandiflora. The principal distinction between these two species is the acidic subfraction of diterpenoic extract, which is antifungic in Eperua falcata when tested in in-vitro conditions. This study also enables to show that ethanolic fraction plays an important role in the mechanism of natural durability. It also reports the first isolation of cativic acid in Eperua falcata wood.
N Amusant, C Moretti, B Richard, E Prost, J M Nuzillard, M-F Thévenon
Di-sodium fluorophosphate, a new fluorine containing, water-borne wood preservative
1986 - IRG/WP 3373
The physical, chemical properties of Di-sodiumfluorophosphate (Na2PO3F) are compared with those of a trade-mark SF-salt. The opposition of biological activity and toxicological data showed that Di-sodiumfluorophosphate may be a suitable alternative to SF-salts ( based on MgSiF6).
D Seepe, W Metzner
Contribution to study of the degradation caused in Pinus spp. poles used in field test
1989 - IRG/WP 1417
The study of the degradation produced by soil natural microflora on wood in contact with it in the field, has been going on for several years now. Our contribution to this aim in the present work has dealt with the possible relationship of the microorganisms in the soil. The microscopic visualization of wood colonization by the microorganisms, and the chemical analysis of the degraded wood compared with the undergraded.
M T De Troya, A Garcia, M J Pozuelo, A M Navarrete, A Cabanas
Efficacy of anhydrides as wood protection chemicals - II. Performance against soft rot fungi
1998 - IRG/WP 98-30174
Pine sapwood modified with various anhydrides and with butyl isocyanate was tested for its resistance to soft rot decay. Small stakes were exposed for 20 months in unsterile soil in a fungal cellar test. Wood modified with butyl isocyanate performed better than any of the anhydrides tested, with a threshold level of protection (less than 3% weight loss) at 12% weight percent gain (WPG). Stakes acetylated to 15% WPG did not give complete protection against soft rot. Stakes modified with alkenyl succinic anhydride showed increasing resistance to soft rot with WPG up to about 10% WPG, above which no further improvements were evident. Succinic anhydride and phthalic anhydride treated stakes showed little or no noticeable protection.
S C Forster, M D C Hale, G R Williams
Discussion of diiodomethyl p-tolyl sulfone (Amical® 48) as a fungicide for wood preservatio
1987 - IRG/WP 3425
The effectiveness of diiodomethyl-p-tolyl sulfone (Amical® 48) as a fungicide for preservation of wood is supported by a discussion of results from the literature and current research programs.
J M Stamm, K J Littel, F M H Casati, M B Friedman
Preliminary results of investigations on screening test of chemical compounds suitable for the preservation of lignocellulosic materials against biodeterioration
1976 - IRG/WP 262
This paper investigates the possibilities of reducing the time needed for the determination of the effectiveness of chemical compounds from the point of view of their eventual application to lignocellulosic materials for preservation against decay and soft-rot.
K Lutomski, S S Neyman
An effective preservative treatment of borak bamboo (Bambusa balcoona Roxb.)
1996 - IRG/WP 96-40070
Adequate penetration and retention of CCA and CCB has been obtained in predried Borak Bamboo (Bambusa balcooa Roxb.), aboundantly grown in Bangladesh, with Full Cell Pressure Process. The treated bamboo can be used as building materials, the sufficient treatability ensured its long term best utilization at ground contact and indoors. Which will keep the environmental & socio economical conditions of Bangladesh more viable and normal.
A K Lahiry, S Begum, G N M Ilias, M A Matin Sheikh, M A B Fakir, M I Hossain
Electron microscopic detection and chemical analysis of three-lamellar structures in wood-destroying fungi
1984 - IRG/WP 1240
In the course of transmission electron microscopical investigations of pine wood decay by various brown- and white-rot fungi extracellular three-lamellar structures (TLS) formed by the fungi were found in specimens stained with ruthenium red. These structures occured in the lumen of the wood cell surrounding the hypha at the outermost layer of the fungal cell wall. In the course of the investigations these structures were also detected in fungi cultivated with glucose on a rotary shaker, where they showed forms similar to tubuli and vesicles. The three-lamellar structures formed by the white-rot fungus Sporotrichum pulverulentum, which were contained in the outermost cell wall layer, were isolated by disintegration of the fungal pellet and subsequent digestion of the fungal cell wall by snail enzyme. It was found that these structures are resistant to the enzymatic digestion and are composed of 80 to 90% carbohydrates, mainly consisting of glucose monomeres, 5 to 10% proteins, containing 5 fractions with molecular weights between 30000 and 200000, and finally 5 to 10% lipids which do not contain any phospholipid.
R Foisner, K Messner, H Stachelberger, M Röhr
Nitrogen content of soils at field sites
1981 - IRG/WP 1133
Nine participants in the Collaborative Field Experiment submitted samples for nitrogen analysis to this laboratory as requested by Leightley (IRG/WP/3162). These arrived in a variety of conditions e.g. wet, dried, sterilised and unsterilised and sometimes spent a considerable time in transit. Soils varied in cellular fraction organic matter content, some were obviously sieved prior to postage while others contained significant quantities of large vegetative detritus. Samples were also taken at different times of the year and seasonal and climatic factors may have influenced the values subsequently obtained by analysis.
B King, G Mowe
Decay patterns observed in butylene oxide modified ponderosa pine attacked by Fomitopsis pinicola
1983 - IRG/WP 1183
Small blocks of ponderosa pine chemically modified by butylene oxide to three different weight percent gains (WPG) were decayed for 2 months with the brown rot fungus Fomitopsis pinicola. Wood substance loss and the type of decay pattern recognised were fairly similar both for control and blocks treated to 8 and 15 WPG. No difference in attack was observed between radial or tangential walls in latewood tracheids. Microscopical examination of undecayed wood blocks treated to 23.7 WPG revealed numerous cracks in both the middle lamella regions of radial walls and in cell corners of latewood tracheids. The fungus had gained entry to the cracks, possibly via bordered pits and rays. Attack started from the cracks and progressed along the middle lamella and towards the cell lumen.
T Nilsson, R M Rowell