Your search resulted in 33 documents. Displaying 25 entries per page.
Some characteristics of Pinus radiata wood from trees subjected to resin extraction
1987 - IRG/WP 3403
35 year old Pinus radiata trees growing in La Puntilla (lat. 37° south, long. 72,4° west), Chile, were subjected to resin extraction 5 years ago. After harvesting them simultaneously with control trees of the same place and age, probes were taken from the bottom of each pole, at 3.4 m, 7.8 m and 11.4 m height. Analysis of ethanol/benzene extract, CCA salt penetration tests and sapstain and brown-rot development rate were performed. The extract content differed in both groups. In the ascendent sense it decreases in unextracted trees and increases in extracted. CCA salt penetration was deeper in treated trees than in untreated. Wood subjectect to resin extraction was less susceptible to sapstain development. No significant difference was detected in both groups in relation to the development of brown-rot.
M C Rose, J Navarrete, G Sandoval, A Bedoya, L Ortega, R Zurita
Modelling of PCP migration in the environment: Feeding the models with laboratory data
1993 - IRG/WP 93-50001-08
In 1989, Hydro-Québec began a study program on pentachlorophenol (PCP) to ensure safe use of the product at all stages. One of the aspects of the study is the creation of a predictive system for evaluating the behavior of PCP and oil migration from wood poles to the environment. This system comprises four mathematical models for predicting PCP and oil migration in and on the surface of the pole, in soil and in groundwater, and for predicting runoff. Laboratory experiments aimed at quantifying and supplying the input for each model have been designed. A method of analyzing both PCP and oil in water. wood and soil has been developed. The radial and longitudinal distributions of PCP and oil concentrations have been established for several combinations of wood species and treatments. Laboratory setups and preliminary results are presented.
A Besner, P Tétreault, R Gilbert
Mold susceptibility of oriented strandboard made with extracted flakes
2008 - IRG/WP 08-40402
As part of a larger study on the manufacture of oriented strandboard (OSB) using hot-water-extracted flakes, the mold susceptibility of extracted-flake and un-extracted-flake OSB was assessed using the standard ‘mold box’ test. OSB made with extracted flakes was much less susceptible to mold. This suggests that the extraction of hemicelluloses and other carbohydrates from wood for the production of biofuel could be combined with the production of OSB with enhanced durability properties.
A M Taylor, O Hosseinaei, Siqun Wang
Properties of hot oil treated wood and the possible chemical reactions between wood and soybean oil during heat treatment
2005 - IRG/WP 05-40304
Thermal treatment with hot oil as the heating media based on the original idea from oil-heat treatment in Germany was investigated. The treatment was mainly carried out at 200ºC and 220ºC for 2 hours and 4 hours, and the wood species were mainly spruce and fir. This paper focuses on the difference between soybean oil and palm oil and the possible chemical reactions between wood and soybean oil. Generally palm oil was slightly better than soybean oil in improving the moisture resistance properties of heat-treated wood. But soybean oil treated wood appeared to have better decay and mould resistance. The mass loss of wood treated in soybean oil at 220ºC for 4 hours was below 20 % after exposure to Gloeophyllum trabeum in a soil block test, so the treated wood can be classified as “Resistant” according to ASTM D 2017 standards. Natural weathering exposure also shows that soybean oil treated wood is more mould resistant than palm oil treated wood. In order to investigate the effects of absorbed oil on the properties of treated wood and the possible reactions between wood and oils, extraction of different vegetable oil treated wood with chloroform and other solvents was carried out. The results suggest that part of the soybean oil could undergo chemical reactions with wood that renders it of low extractability.
Jieying Wang, P A Cooper
Investigation of temperature effect on fixation of Celcure preservative (ACC) in beech (Fagus orientalis)
2001 - IRG/WP 01-40200
In this research, the fixation speed of Celcure 2% (ACC) preservative salt, under temperature of 17°C, 27°C and 50°C, on intact and stained wood specimens of beech was investigated. For this purpose, blocks of wood with 5x5x7 cm dimensions were prepared and saturated with 2% ACC concentration by full-cell process. The specimens were put in three incubators at the above-mentioned temperatures. For measuring the percentage of fixation through time, the specimens were extracted by using hydraulic pressure equipment, under 69 Mpa pressure. The pH of extraction was measured with the method of diphenyl Carbazid and by using spectrophotometer. This measurement was done continuously and the amount of 6- valence chromium concentration present in the extract was compared with the amount of chromium concentration in the primary solution and then the percentage of fixation was calculated. The results showed that the decrease in 6-valence chromium is accompanied with increase of pH, this is due to absorption of positive hydrogen ion by 6-valence chromium for reduction to 3-valence chromium and also ion-exchange of active components with wood during the primary phase of fixation. Also, the time necessary for reaching complete fixation in intact and stained wood in the fixation temperature conditions of 17, 27 and 50°C were 1075, 501, 109 hours, respectively. In general, the results showed that temperature has effective role in accelerating of fixation process and in this respect, intact and stained wood did not show significant statistical difference.
A Karimi, M Ghorbani
Solvent extraction of CCA-C from out-of-service wood
1998 - IRG/WP 98-50107
Elimination of CCA from decommissioned wood prior to disposal is a major environmental issue. One approach is to extract CCA from treated wood, then reuse the 'clean' (may contain CCA, but below hazardous level) wood materials for manufacturing wood-based composites. In the present paper, we focus on effective leaching processes, selection of leaching agents and optimum leaching process parameters (temperature, time and reagent concentrations). These factors are crucial in obtaining high strength 'environmentally clean used wood substrate' suitable in manufacturing boards. Some leaching agents selectively leach certain components of CCA. Different combinations and sequences of leaching were evaluated. All treatments leave significant amounts of some CCA components in the wood, although some combinations of solvents can extract about 90% of all CCA components in 4 hours at a temperature of 50°C. Sequential extraction using formic acid and oxalic acid was one especially effective combination. Solution temperature, concentration and leaching time affect CCA component removal in different ways, depending on the solvent and element extracted. It should be possible to optimize extraction by manipulating these variables.
K M F Kazi, P A Cooper
Durability of heat-treated wood
1999 - IRG/WP 99-40145
Heat-treated wood from the French process were laboratory tested against decay using agar block test and a modified soil block test. Water absorption, bending strength, lignin content and acid number were also determined to evaluate the effect of heat treatment. Heat treated samples exhibit a higher lignin content and a lower acid number compared to untreated control indicating the degradation of some hemicellulose and extractives compounds. The significant amount of water absorbed during water soaking or exposure to different relative humidity suggest that the heat treatment help in releasing the stress in wood after the removal of hemicellulose and degradation of lignin rather than the reported significant cross link reaction of organic acid and the benzene ring of lignin. Cubes extracted with water or acetone or chloroform and challenged with pure culture of fungus show an appreciable weight loss which confirm the absence of any extractable compounds toxic to decay fungi during the heat treatment. After 12 weeks exposure for laboratory soil block or 6 to 8 weeks for agar block test, significant weight loss was observed. For soil block test, weight loss of 11% was obtained for heat-treated samples exposed to G. trabeum and 46% for P. placenta. About 56% and 54% weight losses were obtained for southern pine control exposed to G. trabeum and P. placenta, respectively. The weight loss of water and acetone extracted heat-treated sample exposed to P. placenta was 49.7% and 53.9%, respectively. Only about 11% and 14.8% weight loss was obtained for water and acetone samples challenged with G. trabeum. The moisture content of tested sample was about 70 ±10% for the un-heated control and 50 ± 10% for heat-treated samples. This treatment may modified the durability from non resistant to moderate/resistant species depending on fungus species as defined in the ASTM 2017 standard. The data from the bending test indicate that such treatment may create a 10 to 50% reduction in MOR and deflection which will limits the use of such wood for structural purposes.
D P Kamdem, A Pizzi, R Guyonnet, A Jermannaud
Natural durability transfer from sawmill residues of white cypress (Callitris glaucophylla). - Part 1: Optimisation of the extraction conditions
2000 - IRG/WP 00-30238
As the first phase of a large project aimed at recovering 'waste' durability components from sawmill residues of Callitris glaucophylla, several solvents and extraction methods were evaluated, initially in the laboratory and then at pilot industrial scale. Extracts were compared by crude total dissolved solids content, by chemical analysis using GC-MS and LC-MS, and by laboratory bioassays against termites and decay fungi. Solvent polarity was more important than extraction method: polar solvents extracted greater total amounts, and were comparable to non-polar solvents in extract activity against decay. The latter produced greater specific activity against termites. Drying of sawdust before extraction reduced the yield of some volatile extractive components, but activity was not seriously affected. Extractive components fractionated by column chromatography exhibited a wide range of bioactivities. GC-MS and LC-MS analytical techniques were used to characterise the most active fractions, in which l-citronellic acid and several terpenoids were abundant.
M J Kennedy, Hui Jiang, L M Stephens
Alternative technologies for wood wastes recycling - Part A: Supercritical extraction of PAH compounds from wood wastes
1998 - IRG/WP 98-50101-18 a
Alternative technologies have been investigated to detoxify treated wood. Two classes of organic compounds are studied. Creosote-treated wood are classified in France as dangerous wood wastes. A conventional incineration could be provided for these wood wastes but the cost of this elimination could be very high (> 2000 FFR/ton). For these reasons, we have tested two kinds of new processes as alternative ways. The developed strategy is described in this paper and illustrated by a few examples. Part A - The first one is based on the use of supercritical fluid as C02 to solubilize organic compounds as organochlorine compounds and Polycyclic Aromatic Hydrocarbons (creosote) from treated wood. Kinetics results of this extractive process are presented on the basis of 200 g of wood.
L Schrive, C Perre, G Labat
Recovery of copper, chromium, and arsenic compounds from the waste preservative-treated wood
1991 - IRG/WP 3651
In Japan, about 40 percents of waste wood is incinerated and the residue is dumped into the landfill site. The waste preservative-treated wood, which is mixed in nontreated wood, is incinerated in the same way, too. However, it will cause the serious problems that the gases contained with high concentration arsenic compounds are discharged from the smokestacks of the incineration facilities and the toxic water with high concentrations of copper, chromium, and arsenic compounds is discharged around landfill sites because the residue contains a lot of these compounds. To solve these problems, it is necessary to develop a method to recover these compounds from the waste preservative-treated wood. In this paper, extraction experiments of copper, chromium, and arsenic compounds from treated wood were carried out and evaluated as a method to recover these compounds. Through the experiments, suitable extractant, its concentration, and extraction conditions such as the temperature, extraction time, and the size of test wood piece were obtained. As the results of these experiments, Cr, Cu, and As compounds in the test wood piece were completely recovered into the extractant under the suitable conditions.
A Honda, Y Kanjo, A Kimoto, K Koshii, S Kashiwazaki
A comparison of analytical techniques
1995 - IRG/WP 95-20061
This paper compares carefully-controlled weight retentions and analysis by XRF, ICP, combustion methods and a new extraction procedure for the new preservative, Copper(II) Dimethyldithiocarbamate (CDDC). Various experimental parameters such as particle size and drying conditions were investigated. In general, the correlations between and among the procedures are very high. The extraction-colorimetric procedure developed for assay of CDDC was verified by comparison to AWPA Standard analytical techniques.
A C Gallacher, C R McIntyre, M H Freeman, D K Stokes, W B Smith
Aureobasidium or Hormonema? A Genetic Approach.
2004 - IRG/WP 04-10529
Aureobasidium pullulans is the main organism causing disfigurement of coatings on wood and the surface of exposed timber. This disfigurement of timber in-service is referred to as “bluestain in-service”. A. pullulans is also associated with the sapstaining of dead wood in the forest and in-service. A. pullulans is noted for its highly variable growth forms (polymorphisms). This variability presents problems when identifying environmental isolates, due to the morphological similarity of other blue stain fungi, mainly Hormonema dematioides. Molecular analysis has proven to be both accurate and reliable in distinguishing between these two morphologically similar bluestain fungi. The method was devised as part of a bigger research project designed to look in detail at the polymorphisms and physiology of Aureobasidium-type fungi. The establishment of a working library of strains and isolates was aided by many members of the International Research Group on Wood Preservation. The devised method illustrated the existing problem of distinguishing between A. pullulans and H. dematioides. The protocol has been devised to simplify what can be a long complicated procedure. By sequencing direct from amplified PCR (Polymerase Chain Reaction) products, there is no need for cloning large DNA fragments into vectors, followed by sequencing. The extraction method offered here will give DNA of sufficient purity to allow for further genetic analysis if required. This method allows consistent differentiation between isolates of A. pullulans and H. dematioides. Aureobasidium pullulans is the main organism causing disfigurement of coatings on wood and the surface of exposed timber. This disfigurement of timber in-service is referred to as “bluestain in-service”. A. pullulans is also associated with the sapstaining of dead wood in the forest and in-service. A. pullulans is noted for its highly variable growth forms (polymorphisms). This variability presents problems when identifying environmental isolates, due to the morphological similarity of other blue stain fungi, mainly Hormonema dematioides. Molecular analysis has proven to be both accurate and reliable in distinguishing between these two morphologically similar bluestain fungi. The method was devised as part of a bigger research project designed to look in detail at the polymorphisms and physiology of Aureobasidium-type fungi. The establishment of a working library of strains and isolates was aided by many members of the International Research Group on Wood Preservation. The devised method illustrated the existing problem of distinguishing between A. pullulans and H. dematioides. The protocol has been devised to simplify what can be a long complicated procedure. By sequencing direct from amplified PCR (Polymerase Chain Reaction) products, there is no need for cloning large DNA fragments into vectors, followed by sequencing. The extraction method offered here will give DNA of sufficient purity to allow for further genetic analysis if required. This method allows consistent differentiation between isolates of A. pullulans and H. dematioides.
M J Ray, D J Dickinson, M Buck
Investigation of CCA fixation in wood by sequential extraction. I Determination of CCA component fixation and preliminary extraction results
2002 - IRG/WP 02-50188
The fixation of CCA-C preservative was investigated in sapwood of red pine (Pinus resinosa Ait.), trembling aspen (Populus tremuloides Michx.) and red maple (Populus tremuloides Michx.) at target retentions of 4.0, 6.4, 9.6 and 30.0 kg/m3. Treated wood sawdust was water extracted at close time intervals during the fixation and analyzed for the contents of unfixed hexavalent chromium, total Cr, Cu and As. Fixation curves are similar for red pine and aspen. Chromium fixation is extremely fast in red maple, while significant amounts of unfixed arsenic were present at the time of complete reduction of chromium. In all investigated species, the rate of As fixation increases with the strength of the treating solution, while the rate of Cu fixation decreases. Results of two sequential extraction sequences applied on CCA-C treated wood sawdust, with a range of inorganic and organic solvents, applied in order to dissolve / release one fixation product at the time, are presented. The total content of removed components was analyzed by ICP- AES and content of hexavalent chromium by diphenylcarbazide coloririmetric method. The results of sequential extractions indicate that selective removal of CCA fixation products can be achieved, and this approach may be applied for the investigation of fixation mechanisms. Further research is needed to better understand the particular influence of each of the investigated variables on the course of fixation.
S Radivojevic, P A Cooper
Anti-fungal properties of pyrolytic oils derived from softwood bark
2000 - IRG/WP 00-30218
Thermal decomposition of balsam fir and white spruce mixed bark residues at 450°C and under vacuum (< 20 kPa abs.) results in high yields of pyroligneous liquors rich in phenolic content. This vacuum pyrolysis process has been scaled-up to a pyrolysis plant with a feed capacity of 3.5 t/h of softwood bark, which is the largest plant of this type in the world. The pyrolytic aqueous condensates have been tested for their anti-fungal properties. One of the major objectives of this study was to identify which groups of chemical compounds were the most active to inhibit the growth of wood decay fungi. The fractionation of the pyrolytic aqueous phase in four distinct parts was accomplished by a liquid-liquid extraction method. The four fractions were named F1 (ether extractibles), F2 (ethyl acetate extractibles), F3 (neutral compounds) and F4 (phenolic compounds). Petri tests were conducted using two brown rot fungi (P. placenta and G. trabeum) and two white rot fungi (I. lacteus and T. versicolor). The composition of these fractions was analysed by GC/MS. Fraction F1, with concentrations of organic acids, phenols and derivatives (3.0% by weight), benzenediols (3.9% by weight), and a variety of other products (quinones, furans, etc.), was the most promising to inhibit the growth of decay fungi, while fraction F3 showed no inhibitive effect in the Petri dish agar test. C. versicolor was most sensitive to these fractions, while I. lacteus was the least. The addition of CuSO4 to the water soluble organics improved their ability against decay.
D Mourant, Dian-Qing Yang, Xiao Lu, C Roy
Proposal for a method aiming at the quantification of the impact of wood extraction in Life Cycle Assessment
1998 - IRG/WP 98-50113
Life Cycle Assessment has been accepted as an instrument for the assessment of the environmental impact of products. Characterisation factors for impact assessment of emissions from products have been established. To date no characterisation factor exists for the extraction of biotic resources, for example wood. Since the main disadvantage of using wood as a material lies in the extraction of resources, in view of the rapidly declining world forest resources, this implies that complete LCA studies for such products are not possible. In order to amend this gap, the Centre of Environmental Science and the Centre for Energy Conservation and Environmental Technology in the Netherlands have published a study on development of a methodology for incorporation of extraction of biotic resources, with two case studies on timber and fish (Sas et al., 1997). TNO has now proposed several adaptations to this method. The principle of the method, using indicators for selective harvesting and for degradation of ecosystems remained the same. It is recognized that more work needs to be dedicated to updating and improvement of the quality of the data used. The aim of this paper is to present a case study on a Norway spruce and a Meranti wood product to show the potential of this new method. This may serve as a basis for discussion and as an example for testing the applicability of the proposed method. It is hoped that this will stimulate further research activities in this area.
P Esser, E Van der Voet
Effect of remediation on the release of copper, chromium, and arsenic from particleboard made from CCA treated wood
2001 - IRG/WP 01-50170
This study sought to determine the effect of remediation with oxalic acid (OA) extraction and Bacillus licheniformis fermentation on the release of copper, chromium, and arsenic from particleboard made from remediated wood particles and also investigates durability of the particleboard against white and brown- rot fungi. Particleboard samples were manufactured using untreated, CCA-treated, OA-extracted, and bioremediated southern yellow pine particles. Results shows that oxalic acid extraction and bioremediation by B. licheniformis significantly increased removal of elements from CCA-treated wood particles. The particleboards containing OA-extracted and bioremediated particles showed generally high leaching losses of remaining elements. Exposure of particleboard samples to decay fungi indicated that Gloeophyllum trabeum caused greater weight losses in all samples than Postia placenta. In general, leached samples from all particleboard types had greater weight losses than unleached samples. CCA particleboard samples were the most resistant to fungal degradation.
S N Kartal, C A Clausen
The extraction of boron from treated wood for quantitative analysis: A comparison of procedures
1992 - IRG/WP 92-2414
The extraction of boron preservative from treated rubberwood and scots pine samples was compared using methods based on refluxing and extraction in 1N NaOH or distilled water at 80°C. The extract solutions were analysed by Inductively Coupled Plasma spectroscopy (ICP/AES). A simple extraction procedure based on immersion of wood samples of approximate dimension 2 x 1 x 1 cm³ in distilled water at 80°C was found to give boron retention values comparable to values calculated from solution absorption and values from analysis of the internal standard extract (refluxed). The practical advantages of the simple hot distilled water extraction method are outlined.
R J Murphy, D J Dickinson, P W McCormack, M K Lung
Treatment and recycle of CCA hazardous waste
1993 - IRG/WP 93-50007
Chromated copper arsenate containing hazardous materials is generated from the manufacture, treatment of the wood, and from the wood itself, after its life cycle. Laboratory treating of these wastes has resulted in materials suitable for recycle or disposal as non-hazardous residues. The extraction, by both acidic and ammoniacal routes, of CCA production and treating plant waste materials has been done. Complete extraction of the CCA components is found for strongly acidic reagents. For the ammoniacal systems with various chelating compounds, a variety of results are obtained, ranging from no extraction to nearly complete. Fixative techniques for residues generated from the production of arsenic acid were developed such that the treated wastes pass the U.S. Environmental Protection Agency's Toxic Characteristic Leaching Procedure (TCLP). The burning of CCA treated wood was also investigated. The laboratory experiments show no copper and chromium loss. Experiments with low air flows indicate conditions for which arsenic volatilization approaches zero, i.e., in excess of 1100°C. The resulting ash made of chromium, copper and arsenic compounds offers a feed stream for obtaining these materials.
E A Pasek, C R McIntyre
Quantitative Determination of Cyproconazole in Wood treated with Tanalith CY
2007 - IRG/WP 07-20369
The HPLC method has been widely applied to quantitative determination of cyproconazole in preservative solutions. However, HPLC assay has not been successfully employed to determine cyproconazole content in treated wood. Some extractives from treated wood hinder cyproconazole determination because they have a similar retention time to that of cyproconazole on an HPLC chromatogram. In addition, large peaks of wood extractives appearing at early retention time also affect the determination of cyproconazole. In this paper, the application of solid-phase extraction to remove wood extractives that interfere with cyproconazole determination was investigated. Wood flour from four wood species, namely Japanese cedar, Japanese larch, Yezo spruce and Western hemlock, were treated with Tanalith CY containing copper oxide and cyproconazole as active ingredients. About 1 g of the treated flour was extracted for 2 hours in an ultrasonic bath with 10-50 ml of methanol containing tebuconazole that was used as an internal standard. Methanol extracts were removed with a solid-phase extraction cartridge (Oasis MCX) and finally cyproconazole and tebuconazole were collected. These azoles were then dissolved in a mobile phase for the HPLC analysis and concentrations of the azoles were determined using the software that came with the HPLC system. The results of the HPLC analysis indicate that solid-phase extraction is useful for removing wood extractives that hinder cyproconazole determination. The results also suggest that the volume of methanol solution for cyproconazole extraction from treated wood does not affect cyproconazole determination when tebuconazole is used as the internal standard. Ten ml of methanol is sufficient to get reproducible results for one gram of wood flour.
I Momohara, T Miyauchi, M Mori
Rapid Microwave-Assisted Acid Extraction of Metals from Chromated Copper Arsenate (CCA)-Treated Southern Pine Wood
2009 - IRG/WP 09-50262
The effects of acid concentration, reaction time, and temperature in a microwave reactor on recovery of CCA-treated wood were evaluated. Extraction of copper, chromium, and arsenic metals from chromated copper arsenate (CCA)-treated southern pine wood samples with three different acids (i.e., acetic acid, oxalic acid, and phosphoric acid) was investigated using in microwave reactor. Oxalic acid was effective in removing 100% of the chromium and arsenic at 160°C and 30 min., and acetic acid could remove 98% of the copper and arsenic at the same conditions. Oxalic acid greatly improved the extraction efficiency of arsenic and chromium when time was prolonged from 10 min. to 30 min. Acetic acid also showed improved ability to remove arsenic and copper when the reaction temperature was increased from 90°C to 160°C.
Bin Yu, Chung Y Hse, T F Shupe
Factors affecting sodium hypochlorite extraction of CCA preservative components from out of service treated wood for recycling
2009 - IRG/WP 09-50263
Significant amounts of chromated copper arsenate (CCA) treated wood products such as utility poles and residential constructions remain in service. There is an increasing public concern about environmental contamination from CCA treated wood when it is removed from service for reuse or recycling, placed in landfills or burned in commercial incinerators. In this paper, we investigate the effects of time, temperature and extractant concentration on chromium oxidation and extraction of CCA-C components from treated wood using sodium hypochlorite. Of the conditions evaluated, reaction of milled wood with sodium hypochlorite for one hour at room temperature followed by heating at 75°C for two hours gave the highest extraction efficiency. An average of 95 % Cr, 99 % Cu and 96 % As could be removed from CCA-C treated milled wood by this process. Most of the extracted chromium was oxidized to the hexavalent state and could therefore be recycled in CCA treating solution. Sodium hypochlorite extracting solutions could be reused several times to extract CCA components from new treated wood samples.
E D Gezer, P A Cooper
Microwave-Assisted Organic Acids Extraction of Chromate Copper Arsenate (CCA)-Treated Southern Pine
2010 - IRG/WP 10-50267
The extraction effects of acid concentration, reaction time and temperature in a microwave reactor on recovery of CCA-treated wood were evaluated. Extraction of copper, chromium, and arsenic metals from chromated copper arsenate (CCA)-treated southern pine wood samples with two different organic acids (i.e., acetic acid and oxalic acid) was investigated using a microwave reactor. Oxalic acid was effective in removing 100% of the chromium and arsenic at 160ºC and 30 min. reaction time. Acetic acid could remove 98% of the copper and arsenic at the same condition. Oxalic acid significantly improved the extraction efficiency of arsenic and chromium when time was prolonged from 10min. to 30min. The HSAB (Pearson acid base concept) concept was applied to explain why oxalic acid removed more chromium and less copper compared with acetic acid. Acetic acid also showed an improved ability to remove arsenic and copper when the reaction temperature was increased from 90ºC to 160ºC.
Bin Yu, Chung Y Hse, T F Shupe
Investigating extraction of bifenthrin from composite wood products
2011 - IRG/WP 11-20467
Bifenthrin is added to resin prior to lay-up of plywood and laminated veneer lumber to provide termite protection. Analysis of this chemical in resins can be challenging. The potential for using ground wood in place of sawn material to recover bifenthrin was investigated using laminated veneer lumber composed of Douglas-fir veneers analyzed by three laboratories. Although the results differed among the laboratories, bifenthrin recoveries were almost always higher from ground wood. The results suggest that this method could be modified to allow the use of ground wood if the target retentions were also increased. Other modifications to the standard that could improve bifenthrin recovery and the reproducibility of the method are also suggested.
J J Morrell, L Bell, J Norton, C Shaw
Extraction and analysis of DNA from green and seasoned timber as basic methods for determination of wood species and origin
2013 - IRG/WP 13-20523
Against the background of the European timber trade regulation EUTR, commenced to law by March 2013, the determination of wood species and tracing of its origin is getting a great importance. A promising approach for establishing fast and reliable tracking systems for wood products is DNA analysis. A critical point is the extraction of analysable DNA from the wood and its lignified cell walls. Thus, aim of the work was the analysis of DNA content in different areas of the cross section of green and dry, well-seasoned wood from pine, spruce and beech, using quantitative, real-time PCR analysis. DNA from green timber was successfully extracted and amplified with primer set ycf3hm at all three wood species and zones of cross-section. Whereas the results with pine and spruce confirmed the expectation, that the DNA content decreases from cambium to pith, this was not observed with beech. DNA detection with 20 year old well-seasoned wood was successful only with beech. Further systematic studies are necessary to get better information about the influence of wood processing and ageing on DNA quantity and quality.
K Jacobs, H Mende, W Scheiding
Removal of nano- and micronized-copper from treated wood by chelating agents
2013 - IRG/WP 13-50294
Micronized and nano-copper (Cu)-based and arsenic and chromium-free systems have received much attention for wood protection in recent years. Because they have different fixation, and micro-distribution properties, such copper systems may be more or less subject to release using known remediation methods than soluble forms of Cu. This study evaluated Cu recovery from wood treated with micronized- or nano-Cu via chemical extraction, and determined optimum release rates of Cu from micronized- and nano-Cu-treated wood compared with the release rates from soluble Cu-based wood preservatives. Chemical remediation in the study included chelating agents EDTA, oxalic acid, bioxalate, and D-gluconic acid at different durations, pH, and concentration levels to remove Cu from treated wood along with distilled water as controls. Cu removal rates increased from around 60% to over 95% when bioxalate was employed in the extraction process for all extraction durations. In extractions of nano CuO-treated wood for 24h, oxalic acid was able to remove 95% of Cu; however, bioxalate was able to remove somewhat less Cu. Bioxalate was, on the other hand, more effective than oxalic acid in removing Cu from ACQ-D, MCQ, MCA, CA-C and Cu-Et-treated wood. D-gluconic acid extractions resulted in the lowest Cu removal rate for nano-CuO. As the pH of D-gluconic acid was reduced from 10 to 2, the percentage Cu removal considerably was improved except for nano CuO. Results suggested that there is no distinctive difference in Cu removal rates among ACQ-D/MCQ, CA-C/MCA and Cu-Et wood preservatives. Nano-CuO was found to be resistant against EDTA extractions. Since it is a weak, noncorrosive, nonvolatile, nontoxic, biodegradable and inexpensive organic acid, D-gluconic acid can be used as an alternative to commercial EDTA and bioxalate in chemical remediation of Cu-treated waste wood.
S N Kartal, E Terzi, B Woodward, C A Clausen, S T Lebow