Your search resulted in 553 documents. Displaying 25 entries per page.
Weathering of copper-amine treated wood
2000 - IRG/WP 00-40155
Copper ethanolamine (Cu-EA) treated southern pine (SP) were artificially weathered with a QUV Weathering Tester. The weathering regime was composed of a continuous UV-light irradiation for 2 hours followed by a water spray for 18 minutes for a total time of 1200 hours. The changes on the surface of the weathered samples were characterized by Fourier transform infrared spectroscopy (FTIR) analysis, color and contact angle measurements. FTIR indicates that Cu-EA treatment can retard the surface degradation during weathering. The reduction of the peak intensity at 1510 cm-1, characteristic of the wood lignin was less pronounced for Cu-Ea treated wood than for untreated or ethanolamine treated wood. This reduction in 1510 cm-1 intensity decreases with the increase of copper EA retention in treated wood. The color change expressed by the value of DE indicated that untreated and Cu-EA treated wood change color rapidly during the first 200 hours irradiation and the color change remained relatively constant thereafter. The values of DE for untreated and ethanolamine treated sample were higher than the values of Cu-Ea treated. Changes in the lightness of wood samples were also observed with the duration of irradiation. The lightness of untreated and Cu-MEA treated samples decreased during the first 100-hour weathering. These samples regained their lightness after 100 hours irradiation. For samples treated with copper concentration above 0.25%, the change in lightness was rather small. The contact angle measurement indicates that the wettability of wood surface increases with the duration of QUV exposure. Untreated and MEA treated wood samples changed contact angles rapidly, and The contact angle of untreated and ethanol amine treated samples dropped from about 75"5 degree to zero after 600 hours artificial weathering. Treatment with Cu-MEA can slow the decreasing in contact angle. After 1200 hours, the contact angle of Cu-EA treated wood dropped from 100 to a minimum between 25 and 60 degree. As the copper concentration increases, the rate of changing contact angle decreases. This study suggests that a copper amine treatment increases the hydrophobic and the resitance to photodegradation.
J Zhang, D P Kamdem
Microwave treatment to Accelerated fixation of copper-ethanolamine (Cu-EA) treated wood
2004 - IRG/WP 04-40271
This study evaluated the use of microwave post-treatment to accelerate fixation of copper-ethanolamine (Cu-EA) treated 19 mm southern yellow pine sapwood cubes. Cubes were pressure treated at 3.2 and 6.4 kg/m3 Cu retention target, after which they were microwave post treated during different duration periods. An accelerated AWPA leaching test was conducted during 300 hours to determine the amount of copper leached after the microwave treatment. The amount of copper leached was reduced 40 % after 5-min microwave treatment. The moisture content and the temperature of the cubes were monitored during the microwave treatment. This study clearly demonstrated that post-microwave treatment could be used effectively to reduce the amount of copper leached after 300 hours accelerated leaching test. Further work is needed to determine the effect of the sample size, the power and duration of the microwave treatment on copper leachability.
Jinzhen Cao, D P Kamdem
Microdistribution of Copper in Copper-Ethanolamine (Cu-EA) Treated Southern Yellow Pine (Pinus spp.) related to density distribution
2004 - IRG/WP 04-40270
The relationship between copper absorption and density distribution in wood cell walls was investigated in this study. The density distribution on layer level was obtained from two approaches: (1) calculation by using data obtained from literature; (2) microdistribution of carbon and oxygen atoms in the wood cell. The microdistribution of carbon and oxygen in untreated southern yellow pine (Pinus spp.) sapwood, as well as copper in cell walls of copper-ethanolamine (Cu-EA) treated wood was determined by scanning electron microscopy coupled with energy dispersive X-Ray analysis (SEM-EDXA). Both approaches for density distribution led to the same result: the density was higher in the compound middle lamella (ML) and cell corners (CC) than in the secondary wall. The concentration / intensity of Cu, C and O in the cell wall follow the same trend as the density distribution; suggesting that density may play a major role in SEM-EDXA study of the distribution of metal-containing wood preservatives within the wood cell wall.
Jinzhen Cao, D P Kamdem, E Pasek
FTIR characterization of copper ethanolamine - wood interaction
1999 - IRG/WP 99-20154
The interaction of copper ethanolamine (Cu-EA) and wood components was studied by using Fourier transform infrared spectroscopy (FTIR). In Cu-EA treated wood, significant reduction was noticed on the band attributed to carbonyl vibration from carboxylic groups at 1735±5 cm-1 and an increase in band intensity was obtained from carbonyl in carboxylate at 1595±5 cm-1. The same observation was made in Cu-EA treated holocellulose. Cu-EA treated lignin resulted in a reduction in the aromatic ester band at 1710±5 cm-1 and an increase in carbonyl from carboxylate at 1595±5 cm-1. Bands at 1370 cm-1 and 1221 cm-1 assigned to phenolic hydroxyl groups, exhibited a decrease in intensity after the treatment. From these data, it is concluded that Cu-EA interact with carboxylic groups, phenolic hydroxyl groups and ester groups from lignin to form copper carboxylate and phenolate complexes.
Jun Zhang, D P Kamdem
Copper leaching from copper-ethanolamine treated wood during exposure to terrestrial microorganisms
2013 - IRG/WP 13-30621
Copper-ethanolamine based wood preservatives are still the most important solutions for protection of wood in ground applications in Europe. Wood in ground is exposed to variety of organisms, which can act synergistically. In order to simulate these conditions in laboratory, Scots pine (Pinus sylvestris) specimens impregnated with copper-ethanolamine preservative of three different concentrations (cCu = 0.125%; 0.25% and 0.5%) were exposed to three different soils according to the ENV 807 procedure for periods between 12 weeks and 32 weeks. After respective periods of exposure, samples were isolated and their mass loss, bending strength and modulus of elasticity were determined. In the final step remaining copper in the samples was determined. The results showed that in spite of the prominent copper leaching, tested copper-ethanolamine treated wood exhibited good performance in ground applications. Furthermore, it is evident, that there is a good correlation between mechanical properties and mass loss determined, regardless of the chemical treatment applied.
M Humar, N Thaler, B Lesar
Improved PEC preservatives with added biocides
1985 - IRG/WP 3322
Biocidal chemicals have been incorporated into formulations within the broad framework of pigment emulsified creosote (PEC) to provide novel potential multi-purpose preservatives. Preparations of PEC plus TCMTB, Boracol 40, copper ethanolamine nonanoate, Quatramine 80, arsenic trioxide, Troysan Polyphase, and CCA have been formulated and assessed for preserving ability in soil-jar and Accelerated Field Simulator tests. In addition, a cationic oil-in-water emulsion preservative combination of PEC and CCA (PECCA), and an anionic formulation of TCMTB with PEC (PECBUS) have been manufactured in 400 L quantities to treat hardwood pole stubs and pine posts. The results indicate the potential of these improved second generation PEC-based preservatives to provide low-creosote containing treatments able to protect commodities against biodeterioration as well as provide dry, clean surfaces.
H Greaves, C-W Chin, J B Watkins
Evaluation of wood treated with copper-based preservatives for Cu loss during exposure to heat and copper-tolerant Bacillus licheniformis
1999 - IRG/WP 99-20155
Copper-based wood preservatives need to be effective against exposure to all types of microorganisms. Wood treated with six copper-based preservatives was exposed to 121°C and 20 psi pressure for 15 minutes under standard autoclave conditions and the copper-tolerant bacterium, Bacillus licheniformis CC01, for 10 d at 28°C and 150 rpm. Sixteen to 37 percent of the copper was released from the wood during autoclaving, with copper citrate demonstrating the highest percent loss. Forty-four to 82 percent of the copper remaining in the samples following autoclaving was removed during exposure to the bacterium in liquid culture; copper naphthenate in oil and ACQ-D had losses of eighty percent or greater of the remaining copper. The bacterium removed as much or more total copper in 4 of 6 gas-sterilized samples (85-94%) than the cumulative effects of steam-sterilization and the bacterium on treated samples. Copper loss from in-service treated wood compromises the efficacy of copper-based wood preservatives.
D M Crawford, C A Clausen
EPR investigations of interactions between ammoniacal Cu(II) octanoate and wood
1996 - IRG/WP 96-30110
Ammoniacal solutions of copper(II) octanoate [ C u . h l f . 2 . r h l f.(O2CC7H15)4], interactions of these solutions with wood and wood components, and leaching of copper(II) octanoate from impregnated wood samples, have been studied by electron paramagnetic resonance (EPR) method. It is still not clear if in the Cu(II) octanoate - water - ammonia system, Cu(II) remains in a (copper(II) octanoate - ammonia) complex. The majority of leached Cu(II) with distilled water and a solution simulating acid precipitations was washed out in the first five hours of leaching procedure (up to 35% of initial Cu(II)). Time dependence studies of interactions of ammoniacal Cu(II) octanoate with wood, cellulose and brown rotted lignin showed, that the fastest and most significant was the reaction with lignin. Cu(II) is immobilised also on cellulose. A significant contribution of ammonia evaporation to the fixation mechanism of the preservative was observed as well.
F Dagarin, M Petric, F Pohleven, M Sentjurc
The course of fixation of Cu-Cr-As wood preservatives
1972 - IRG/WP 307
Copper-chrome-arsenic (CCA) preservatives in contact with wood result in an instant extensive increase of pH, because of ion-exchange and adsorption reactions with the wood. During precipitation of the active elements the pH continuously increases but reaches a maximum, when all chrome is consumed. Some of the early reaction products are unstable and slowly convert via dissolution into stable compounds. The conversion proceeds by proton liberating as well as proton consuming reactions. The pH therefore alternatively decreases and increases until the reactions cease after several months. The final equilibrium fixation products are: ion-exchange fixation of Cu to the wood CrAsO4, Cu(OH)CuAsO4 and Cr(OH)3. The chrome fixation is 2nd order with respect to hexavalent chrome in the liquid phase, four regions with distinct chrome fixation rate constants were found. A hypothesis is given for the mechanism of fixation.
Determination of ethanolamine in impregnated wood
2000 - IRG/WP 00-20198
Leaching of copper based preservatives from wood is usually prevented by adding chromium compounds to copper containing formulations. It seems that suitable substitutes for chromium fixation agents may be amines. In this paper, we report our results on interactions between copper(II) octanoate and ethanolamine (C2H7NO, 2-aminoethanole) with wood or its components. A part of ethanolamine from a wood preservative chemically reacts with wood and does not evaporate from it. This can be seen from retentions and from the changes of FTIR spectra of treated wood. We assume that ethanolamine mainly reacts with hemicelluloses and lignin complex. The unevaporated part of ethanolamine is even higher (for 2%) in the presence of copper(II) octanoate. We think that this difference originates from ethanolamine, which is complexed to copper(II) octanoate. Ethanolamine in wood can be easily determined with the indicator bromphenol blue in ethanol/acetic acid aqueous solution. Wood with ethanolamine turns blue while wood without ethanolamine remains yellow.
M Humar, M Petric
Influence of carboxylic acids on LEACHING of copper amine based preservatives
2005 - IRG/WP 05-30365
The importance of chromium free preservatives is increasing. Leaching of copper from wood preserved with such solutions is still higher compared to leaching from wood impregnated with copper chromium ones. In order to decrease leaching, different carboxylic acids (octanoic, 2-etilheksanoic, decanoic) were added to copper/amine/boron aqueous solutions. Experiment of leaching of copper from Norway spruce (Picea abies) was performed according to the modified standard procedure (EN 1250). Results presented in this paper showed, that carboxylic acids significantly improve copper fixation. The best one was determined at specimens impregnated with the preservative solutions consisting of copper, ethanolamine, boric acid and octanoic acid.
M Humar, P Kalan, F Pohleven
Environmental fate of copper-based wood preservatives in different soil substrates - Part 1: Screening of the metal adsorption potential
1998 - IRG/WP 98-50101-21 a
In treatment plants, spillage of wood preservatives onto soil may be of environmental concern. This potential soil contamination served as an objective for a screening study. Three different mineral soils, a mineral substrate and two horticultural substrates are examined for their sorptive potential of copper through mixing with wood preservative solutions. Depending on the soil/substrate characteristics and the chemical nature of the preservatives used, copper is adsorbed to a higher extent with increasing concentration of the test solution. Soils with low organic matter and clay content show an upper limit of adsorption, irrespective of the product tested. The other soil types clearly exhibit a levelling-out effect from 2 to 4 hours on, often correlating with the initial metal concentration of the product though dependent on the chemical nature and buffering capacity of the active ingredients.
G M F Van Eetvelde, J M Mwangi, F Tack, R Hartmann, M Stevens
Microwave digestion of preserved wood for the determination of Cu, Cr, As, B and P in quality control
1991 - IRG/WP 2364
A microwave digestion method for the determination of copper, chromium, arsenic, boron and phosphorus in preserved woods is described. Samples were digested with nitric acid in pressure-relief type teflon PFA vessels by microwave heating in a commercial laboratory microwave oven. Fast, efficient and complete digestion was achieved within 29 min for 12 samples. The digestion time compared favourably with the 2 h required for conventional procedures. Furthermore the consumption of reagents was reduced significantly. The resulting solutions were analysed by inductively coupled plasma atomic emission spectrometry, but the solutions are also suitable for atomic absorption spectrometry.
N Bernth, L B Sheard
Studies of the mechanism of chromated-copper preservative. Fixation using electron spin resonance
1992 - IRG/WP 92-3701
Two softwoods and one hardwood species were treated with chromium trioxide, copper sulphate, chromated-copper wood preservative (CCA). The treated wood samples were analyzed during fixation by electron spin resonance (ESR). ESR spectra indicated that more than one Cr(V) species was generated from Cr(VI) soon after CCA treatment. The Cr(V) signal became strong within increased several hours followed by the gradual decay of Cr(V) accompanying with generation of single broad Cr(III) species. Cr(V) signal still remained at least up to six months after the treatment. ESR spectral parameters from Cu(II) signal consisted of a quadruplet at lower field with a unresolved absorption of higher field, suggesting a evidence of a dX²-Y² ground state of Cu2+ ions bound in inner-sphare complexes with "O4" ("O6") ligands arranged in square planar cordination (distorted octahedral) cordination. Cu(II) signal did not change significantly during fixation.
K Yamamoto, J N R Ruddick
The content and mobility of copper, chromium and arsenic in the soil of a wood preserving plant using CCA
1998 - IRG/WP 98-50122
Analyses were carried out on soil and water samples obtained from a wood preserving plant using CCA-type preservatives. The plant has been in operation since 1969. The soil samples were obtained on 8 points from 4 different depths. The estimation of the type of soil was followed by investigations of copper, chromium and arsenic contents, and the mobility of these elements. The soil samples were also analyzed for their organic material and carbon contents. Water sample, obtained from a well within the area of the plant, and wood samples, from trees grown in the area, were also analyzed using Atomic Absorption Spectroscopy. In the desorption tests using acidic medium soils yielded among 1 and 513 mg/kg As, between 6 and 1945 mg/kg Cu, between 21 and 2400 mg/kg Cr; using distilled water they yielded between 1 and 23 mg/kg Cr; Cu concentration remained below the detection limit of the method applied.
N Erdin, S N Kartal, A Dilek Dogu, M O Engür
Determination of bis-(N-cyclohexyl-diazeniumdioxy)-copper in different matrices by photometer, thermal energy analyzer and HPLC
1999 - IRG/WP 99-20179
For the quantitative analysis of bis (N-cyclohexyl-diazeniumdioxy)-copper (Cu-HDO) three analytical methods are used. The employment of the different methods depends on the matrices involved. For several years now, the colorimetric determination of Cu-HDO by photometer has been applied to solutions and concentrates of wood preservatives. In principle, the technique consists of a quantitative conversion of Cu-HDO into a Fe-complex and the measurement by photometer compared to a calibration curve in a range of 20 to 220 mg Cu-HDO per liter. The colorimetric technique is unsuited to extracts of complicated materials such as soil or wood because of disturbances due to other ingredients of these matrices. Further, the method is not suitable for samples with a concentration below 10 mg Cu-HDO per liter. In the case of difficult analytical problems in the determination of Cu-HDO (e.g. soil or air from working areas) another technique, involving the detection by Thermal Energy Analyzer (TEA), is applied. In the first step of the method, Cu-HDO sets nitrogen monoxide (NO) free by a reduction reaction with NaI / acetic acid / sulphuric acid in a laboratory converter. A helium gas flow transfers the nascent NO into the TEA. There, NO is detected by chemiluminescence which originates from its reaction with ozone. The large expenditure of work and the high costs of the instrumental equipment are handicaps for a wide use of the analysis by TEA. A new technique based on the widespread analytical system HPLC was therefore developed to determine Cu-HDO in the important matrix wood. The chipped wood sample is first leached by a mixture of methanol p.a. and 0,05 M KH2PO4-solution at room temperature and the content of the active substance subsequently analysed in the filtered extract by HPLC with UV-detection. The concentration is calculated on the basis of external standard calibration. In studies carried out on impregnated pine samples (pinus sylvestris) in different laboratories, percentage recoveries for Cu-HDO of more than 80% were achieved.
J Wittenzellner, W Hettler, M Maier
A comparison of the leaching resistance of copper 2-ethanolamine and copper ethylenediamine treated Scots pine
2000 - IRG/WP 00-30233
The depletion of copper from copper 2-ethanolamine and copper ethylenediamine treated Scots pine blocks was investigated. A greater leaching resistance was found for copper 2-ethanolamine, which retained ca. 86% and ca. 50% copper after water and buffer leaching, respectively. Leached amine treated blocks also contained significant residual amine. This was consistent with other observations linked to the formation of amine acid salts in amine treated wood. The results also suggested that significant loss of copper, due to formation of copper acetate can occur.
Xiao Jiang, J N R Ruddick
Addition of boron compounds and octanoic acid for improvement of biocidal properties and copper fixation at copper-ethanolamine based wood preservatives
2006 - IRG/WP 06-30408
Copper-ethanolamine based wood preservatives became important active substance (formulation) for wood protection, novelty. As copper itself can not ensure sufficient protection against wood destroying organisms and fixation in wood we combine it with other biocides like ethanolamine, boron and octanoic acid. This investigates were performance on spruce wood impregnated with different combination of copper-ethanolamine, boron and octanoic acid in aqueous solution. Copper fixation was determined according to the modified ENV 1250 standard method, while fungicidal testing against Trametes versicolor, Gloeophyllum trabeum and Antrodia vaillantii were performed according to the mini block procedure and termiticidal activity was determined using Kalotermes flavicollis. The results showed that addition of boron increases copper leaching, but on the contrary improves efficacy against wood decay fungi and termites. On the other hand, addition of octanoic acid improves copper fixation, and slightly decreases effectiveness against copper tolerant fungi.
F Pohleven, M Humar
Influence of ethanolamine on lignin depolymerization and copper leaching from treated Norway spruce and beech wood
2007 - IRG/WP 07-30423
Copper-ethanolamine based wood preservatives are replacing several classical copper-chromium based solutions, due to foreseen ban of chromium. Fixation of copper-ethanolamine based wood preservatives is not as good as fixation of copper-chromium ones. The main object of this manuscript was to prove, that ethanolamine is the prime reason for insufficient fixation of copper-ethanolamine formulations. Ethanolamine causes depolymerization of lignin, what consequences in increased leaching. In order to prove that presumption, Norway spruce (Picea abies) and Beech (Fagus sylvatica) wood specimens were impregnated with three different aqueous solutions consisting of copper-ethanolamine and additives/co-biocides of three different concentrations. After four weeks of fixation, those specimens were leached for seven days. Mass change after leaching was measured gravimetrically. Modulus of elasticity (MoE) was determined using non-destructive technique. In parallel, copper, nitrogen and carbon contents were analysed in leachates and carbon and nitrogen content were measured in leached and un-leached wood blocks as well. The results showed that presence of ethanolamine in preservative solutions caused MoE change. In leachates significantly increased carbon as well as copper contents was determined. There was good correlation between organic carbon in leachates and copper leaching. The main source of organic carbon was wood components. Therefore, we believe, that our hypothesis of ethanolamine induced lignin depolymerization is confirmed.
M Humar, B Bucar, M Zupancic, D Žlindra, F Pohleven
Toward an assessment of copper bioavailability in treated wood
2010 - IRG/WP 10-20445
Many modern wood preservative systems rely on copper (Cu). Some oxalate-producing fungi detoxify Cu by immobilizing it in crystals, and this may decrease its physiological availability (bioavailability). Cu bioavailability may also decrease during wood treatment. Cu retention in wood, however, is typically measured as a weight-to-volume concentration without an estimate of its bioavailability and without assessment of its relative contribution to preservative efficacy. We have begun assessing bioavailability of Cu in treated wood, using oxalate to pretreat wood and exposing wood to colonization by a fungus moderately-tolerant of Cu. In our first efforts, we treated Cu-impregnated wood with gradients of sodium oxalate and exposed rinsed wood in soil-block microcosms to Serpula himantioides. Cu ethanolamine (C-EA)-treated wood effectively prevents decay by S. himantioides, but toxicity can be overcome above a threshold level of oxalate pretreatment. In agar microcosms, C-EA wood stimulates oxalate production by S. himantioides, but the concentration of induced oxalate remains below the threshold determined in the soil-block trial and decay is low. We are working to improve the sensitivity of this biologically-relevant assay, but wish to share the idea with treaters and others with applied aspirations so that any emerging approach might better serve the wood protection community.
J S Schilling, J J Inda
Adsorption of ACQ components in wood
2010 - IRG/WP 10-30522
To investigate the chemical adsorption capacity of copper-monoethanolamine (Cu-Mea) components on wood, the Na+ cation exchange capacity (CEC) of red pine (Pinus resinosa Ait.) was determined and compared to the adsorption capacity of free Mea and Cu-Mea complexes. The CEC increased with increasing pH. Free Mea adsorption as a function of pH followed the sodium adsorption curve except at pH over 9, when it exceeded the CEC. Cu-Mea adsorbed up to the CEC at pH 9.0-9.5 apparently as Cu(Mea)+, whereas the complex in solution is predominantly of the form Cu(Mea)2+. For the quaternary ammonium compound, alkyl dimethyl benzyl ammonium chloride (ADBAC) adsorption isotherm showed two different adsorption mechanisms into wood: ion exchange reaction at low concentration and hydrophobic interaction at high concentration. ADBAC adsorbed at solution concentrations below a critical concentration (hemi-micelle concentration) had high leaching resistance while ADBAC adsorbed into wood at above the critical micelle concentration (CMC) had low leaching resistance. The CMC decreased with addition of Mea and Cu-Mea. The anion, Cl- of ADBAC was only adsorbed at solution concentrations above the CMC and was easily leached out. The adsorption capacity of ADBAC into wood by cation exchange reaction did not achieve the cation exchange capacity (CEC) of wood. However, the total adsorption of ADBAC and Cu achieve the CEC of wood in the presence of copper amine, and ADBAC competes with copper to occupy the same sites in wood.
Myung Jae Lee, P Cooper
Influence of wood swelling agents on penetration and copper leaching of copper-ethanolamine based wood preservatives
2011 - IRG/WP 11-30556
Copper ethanolamine based preservatives are currently the most important solutions for impregnation of wood in ground contact in Europe. One of the issues related to those and similar water based solutions is insufficient penetration to refractory wood species like Norway spruce. In order to elucidate this issue, commercial copper ethanolamine based solution was supplemented with five different wood swelling agents (ammonia, ethylene glycol, DMSO, formic acid and triethanolamine) of three different concentrations (2.5%, 5% and 10%). Norway spruce wood specimens were impregnated with those solutions, and uptakes of preservative solutions and depth of penetration was determined. Furthermore, copper leaching according to the ENV 1250-2 procedure was determined as well. The results showed that triethanolamine and formic acid were found very effective and improved penetration of copper ethanolamine wood preservative to wood. On the other hand, addition of those two preservatives increased copper leaching from impregnated wood.
M Humar, N Thaler, B Lesar
A case study of investigating fungi that affect traditional Japanese shake roof with/without copper plates
2013 - IRG/WP 13-10810
A Japanese traditional shake roof is made from split logs. To keep the roof long, copper (Cu) plates are often inserted between the shakes. It has been thought that Cu elements from copper plates would flow out when a shake roof is exposed to rain and inhibit growth of wood rotting fungi. Actually there are some examples where the Cu plates seem to be effective in preventing fungal damage, but on the other hands, there are also cases that significant rot is observed even with insertion of Cu plates. It is important to look at what is going on in such wooden roofs, by describing levels of damage of rot and investigating fungal species, which are involved in the damage. In this study, we investigated a case of shake roof where Cu plate usage seemed to have inhibited wood rot. Wooden parts away from copper plates were decayed with deep cracks, and wooden parts under a copper plate have been preserved well and maintained its original form. Wooden samples, which did not have significant decay visually, were taken from the areas just under copper plates. Also wooden samples, which had severe decay, were taken from areas without copper plates. Filamentous fungi in both types of samples were identified using a cultivation method on malt extract agar (MA) medium and a non-cultural method, the next generation sequencing method. Fungal strains were isolated on MA plates from ethanol-sterilized wooden pieces and non-sterilized pieces respectively, to see fungal species rich on the surface and inside the wooden pieces. Surface sterilization resulted in a big difference from the results obtained with non-sterilized samples. But for now it is unclear whether there are difference in fungal species between the samples taken from the areas adjacent to Cu plates and samples taken from the areas without Cu plates. By using next generation sequencing technology, 12826 (Sample 1, away from copper plates) and 7086 sequences (Sample 2, just under a copper plate) were yielded. ITS DNA sequences from Sample 1 (samples taken from areas without Cu plates) were divided into 3 groups. The main group (11619 sequences) was highly-homologous to species classified as wood rot fungi. The other groups were classified as ascomycetes. On the other hand, ITS DNA sequences from Sample 2 (samples taken from the areas adjacent to Cu plates) were divided into many groups but all the sequences were classified as ascomycetes. Such difference may reflect the states of wood rot, between the Cu plus and Cu minus samples examined in this study.
T Wada, Y Fujiwara, Y Fujii, R Kigawa
Performance of untreated wood and wood impregnated with copper-ethanolamine based preservative solutions in Northern Adriatic Sea
2013 - IRG/WP 13-30623
Sea water applications of wood are among the most challenging ones. Impregnated wood is exposed to leaching and to variety of marine borers, Limnoria sp. and Teredo sp. being the most important. In the present research, durability of pine wood impregnated with copper-amine based preservative solution (Silvanolin) of different concentrations, exposed to the sea water, was investigated according to the EN 275 standard. Performance of Silvanolin treated wood was compared to performance of naturally durable wood (Quercus sp., Castanea sativa, Larix decidua). After 10 months, 18 months and 32 months of exposure, the samples were isolated and assessed. From the presented results it can be clearly seen, that durable wood species were completely degraded after 10 months of exposure. On the other hand, it is evident that Silvanolin prolongs the service life of exposed wood in the sea. The specimens impregnated with the lowest concentration of the preservative solution (cCu = 0.31 %) were only slightly decayed. At specimens, impregnated with higher concentrations of copper (cCu > 0.31 %) almost no defects were observed as a results of exposure to marine borers.
M Humar, M Petrič, J Adamek, B Lesar
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