Your search resulted in 727 documents. Displaying 25 entries per page.
Soft rot and bacterial decay in preservative treated eucalypt power transmission poles
1982 - IRG/WP 1155
Bacterial type decay was observed in CCA and PCP treated eucalypt power transmission poles. Detailed observations made with the SEM revealed bacterial colonisation and decay, especially in fibres. Plug samples taken from poles throughout Queensland were examined for preservative retention and presence of soft-rot decay. The severity of decay was different according to location, retention and species.
L E Leightley
Diffusion of a copper naphthenate/boron paste through Douglas fir heartwood
1991 - IRG/WP 3671
Groundline wraps are an important portion of the remedial treatment strategies for protecting utility poles in North America from surface decay. The compositions of these wraps have recently shifted away from pentachlorophenol and creosote to formulations containing copper naphthenate and boron. These formulations have not yet been extensively tested, although the chemicals have been used for many years in other applications. Radial and longitudinal diffusion of the components of a copper naphthenate/boron paste was studied in Douglas-fir heartwood blocks at 30 and 60% moisture content. Longitudinal orientation and higher moisture levels resulted in greater diffusion of both components. Boron diffused faster than copper naphthenate over the 6 month test period, but the degree of copper movement was substantial. The results suggest that this copper/boron paste can readily diffuse through normally refractory heartwood. Field trials are underway to evaluate the biological efficacy of this formulation.
P G Forsyth, J J Morrell
Influence of variable lignin content amongst hardwoods on soft-rot susceptibility and performance of CCA preservative
1982 - IRG/WP 1151
This paper presents the outline of an argument, based on both new and established data, which relates varying lignin content to variation of soft-rot susceptibility between hardwood species and of performance of CCA preservatives in controlling soft-rot. Although more data need to be generated to prove this relationship, sufficient evidence exists for the hypothesis to be given close attention, particularly as it may provide the link between previous and apparently conflicting theories which attempted to explain the disparate performance of CCA in hardwoods. There are some difficulties in presenting the argument in logical sequence at this stage, so the approach taken has to follow the sequence of events which led to the present conclusions. The paper should therefore be considered as a preliminary draft which may be subject to modification especially as it does not follow a conventional format.
J A Butcher, T Nilsson
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
The growth and metal content of plants grown in soil contaminated by a copper/chrome/arsenic wood preservative
1977 - IRG/WP 3110
Salts of copper, chromium and arsenic are used together in water soluble formulations for the preservation of wood against insect and fungal attack. Copper/chrome/arsenic (CCA) preservatives are of proven efficacy and, used correctly, ensure a useful service life for timber for 30 years or more with little, if any, attendant threat to the environment from the treated wood itself. The preservative treatment site can, however, provide a point of entry for the preservative into the general environment by way of spills and leaks of the treating fluid and run off from treated wood, with resultant contamination of the surrounding soil. The possible effects of the CCA salts on plant growth and metals uptake are the subject of this paper. In a series of greenhouse pot experiments the effects of varying concentrations of CCA in soil on the germination, growth and cropping of beans, carrots and tomatoes was studied. Crops produced by the plants were analysed for their copper, chromium and arsenic contents. Additionally, grasses were grown to assess possible land reclamation difficulties. It was found that soil having a combined copper, chromium and arsenic concentration of approximately 7000 ppm completely inhibited the growth of all the plants tested, while certain concentrations below this inhibited or retarded growth to some degree. Carrots grown in soil containing approximately 1000 ppm Cu, Cr, As (200 ppm As) produced crops containing nearly twice the current recommended limit for arsenic in food. Relating the levels of CCA used in the experimentally dosed soil with the amounts found in soil samples taken from preservative treatment sites, it is apparent that many contaminated areas would not support plant life. Less heavily contaminated soil will support growth and may give rise to crops with arsenic levels higher than those deemed to be safe.
C Grant, A J Dobbs
Comments on soft rot attack in timbers treated with CCA preservatives: A document for discussion
1982 - IRG/WP 1167
This paper is not based on any particular results but rather on several observations of soft-rot during many years of studies, and on a review of the existing literature. The short time available has unfortunately not permitted a detailed review of the literature. Data and knowledge of important facts are lacking for several aspects of soft-rot attack and for reactions occurring in the wood as a result of the treatment with CCA preservatives. This has made several assumptions necessary and a number of suggestions are being made which are not backed up by results. But this document may nevertheless provide a basis for discussions. Hypothesis: (1) Soft rot attack in low susceptibility wood species is prevented at CCA levels which are too low for preventing growth of soft-rot fungi. (2) High susceptibility hardwood species are only temporarily protected by high retentions of CCA. The concentrations of CCA required are so high that they will be expected to considerably effect the grawth of soft-rot fungi. (3) Formation of T-branches is induced by a chemical factor, most probably of carbohydrate nature, in the wood cell walls. (4) The number of sites where this chemical factor occurs is depending on the carbohydrate/lignin ratio. Few sites occur in high lignin timbers whereas a high number of sites can be expected in low lignin timbers. (5) CCA treatment masks or modifies the sites so that the penetrating hyphae are unable to detect them. The masking is complete in timbers with a high lignin content whereby soft-rot attack is prevented. Only partial masking occurs in hardwoods with a low content of lignin which will allow soft-rot attack to occur. But the soft-rot decay rate is such hardwoods treated to high retentions of CCA will be reduced because of the toxic effects of the preservative.
The movement of iron into field test stakes
1987 - IRG/WP 2284
Failed and sacrificial stakes recovered from the Westham Island field test site were examined for their iron content. Varying amounts were recorded, which were greatest in the failed stakes. The possible role of the iron taken up by the below ground portion of the stakes, in accelerating the decay process and/or the preservative leaching is under investigation. The reaction of the iron with the chrome azurol S reagent normally used to assess copper penetration, has important implications when measuring the penetration of chromated-copper and ammoniacal copper preservatives in field test material.
J N R Ruddick, P I Morris
Changes of copper and chromium content after leaching in wood impregnated with the CCB and CB preservatives
2000 - IRG/WP 00-50147
The objective of the study was impregnated with CCB and CB preservatives pine wood of moisture content varying from 12% to 55% subjected to leaching. Losses of copper and chromium were determined for individual layers of wood up to 3 cm from the girth. The results were compared to the total amount of metals determined in water extracts. The degree of leaching of metal ions from wood of 55% moisture content was higher than for air-dry wood. Spectrophotometric analysis of individual layers of wood after leaching revealed in some cases the increase of metal ions concentration in deeper layers.
CCB Preservative treatment of split muli (Melocanna baccifera ) bamboo by soaking process
2006 - IRG/WP 06-40336
This study was carried out in order to investigate the retention of chemicals inside the split muli ( Melocanna baccifera ) bamboo after preservative treatment by soaking process. Treatment with 10% aqueous solution of CCB (copper-chrome-boron) was applied in split bamboo of two sizes (1/4 part and 1/8 part) at three different moisture contents and five time periods (24, 48, 72, 96, 120 hours). It was found that maximum retention was found in split bamboo both ¼ part and 1/8 part at 15% moisture content. Due to more exposed area 1/8 part split bamboo attained more chemicals than ¼ part split. It was found that after 72 hours soaking the retention of the chemicals were 8.82 Kg /m3 and 11.46 Kg/M3 for ¼ and 1/8 split bamboo respectively which is sufficient to protect split bamboo in outdoor condition.
K Akhter, M H Chowdhury
Effect of barriers on moisture content of treated and non-treated utility poles
2007 - IRG/WP 07-40369
The potential for non-biocidal barriers to slow moisture sorption was investigated using butt treated western redcedar poles immersed in either water or moist soil over a 2 year period. Moisture sorption was initially slowed by the barriers, but openings at the bottoms of the barriers eventually allowed moisture to migrate upward. Moisture levels in wrapped poles eventually reached those found in non-wrapped poles. Despite the apparent lack of difference in moisture content, the barriers other useful attributes including limiting loss of preservative and restricting access of soil fungi to the wood surface may make them attractive in some applications.
C S Love, J J Morrell
Effects of acetic acid and nitric acid pre-treatment on copper content of spruce wood treated with CBA-A and CCA
2008 - IRG/WP 08-40406
This work investigates the effects of nitric acid and acetic acid on compression strength values and copper retention contents of refractory spruce wood (Picea oriental L.) treated with the waterborne preservative Copper azole, (CBA-A, Tanalith-E 3492) and copper / chrom / arsenic (CCA). Before the CBA-A and CCA treatment, the samples were immersed in 500 ml of nitric and acetic acid solutions for two different durations (3 and 6 hours). A 2 % active ingredient solutions of CBA-A and CCA were applied for use in vacuum treatment of the sapwood samples. According to the results, average copper contents of the specimens were higher than that of the control groups except of the 3-hours nitric acid treatment in CCA and CBA-A impregnation. Acetic acid exhibited better performance than nitric acid although it was used at lower concentration. The highest copper content values were obtained in the variations of the 6-hours acetic acid pre-treatments for both CCA and CBA-A impregnations. Compression strength values generally slightly increased compared to the control groups.
S Yildiz, E Dizman, Ü C Yildiz
Quantification of copper and chromium in field stakes after different exposure times: Remaining metal content and distribution
2013 - IRG/WP 13-50291
In order to determine the distribution of copper and chromium as well as their remaining concentration EN 252 specimens and thicker pine sapwood stakes (non standard format) were treated with a commercial CC salt in a vacuum pressure process. The stakes were installed in the test field of the Institute of Wood Research, Hamburg, in August 2010. In all cases three stakes were removed after 4, 8, 12, 16 and 20 months of exposure, whereby the metal content was analysed after sample preparation. Based on these data and under consideration of the analytical values of unexposed stakes the remaining metal content was calculated for the above and in ground section. The results illustrate that 84 % of the copper remained in the full EN 252 samples and 77 % in the non standard stakes whereas the chromium content corresponds to 95 % and 85 %, respectively. On the other hand the data illustrate that in both sample sizes the highest copper and chromium amount was found in the above ground portion after exposure.
T Liese, M Bahmani, E Melcher
Preliminary study of the fungicidal and structural variability in copper naphthenates and naphthenic acids
1996 - IRG/WP 96-30114
Copper naphthenates, an oil-borne wood preservative listed by the American Wood-Preservers' Association (AWPA), is manufactured by complexing copper(II) with naphthenic acids. Prior to AWPA listing as a wood preservative, field experiments showed that copper naphthenates generally had good stability and were active against wood-destroying organisms. Recently, however, there have been reports of some copper naphthenate-treated poles rapidly failing. One possible explanation for the varying effectiveness could be that the structure, and resulting biological activity, of the naphthenic acids used to make copper naphthenate may vary. To test this hypothesis several naphthenic acids and copper naphenates were obtained and their fungicidal activity against three wood-destroying fungi measured. In addition, the chemical structure of the naphthenic acids were examined by proton- and carbon- NMR. Different activities were observed, especially against a copper-tolerant fungus. Some apparent correlations were seen between the fungicidal activity and chemical structures for the few samples studied.
T Schultz, D D Nicholas, L L Ingram Jr, T H Fisher
Sequestration of copper ions by the extracellular mucilaginous material (ECMM) of two wood rotting basidiomycetes
2004 - IRG/WP 04-10533
The radial growth rate of colonies originating from either whole or ECMM-free inocula of Coriolus versicolor was investigated. The presence of ECMM allowed colonies to maintain higher growth rates than those form ECMM-free inocula up to 2 mM CuSO4 in the medium. The ECMM of C. versicolor and G. trabeum was able to reduce the diffusion of copper ions in solution. The ‘raw’ ECMM of both fungi had a greater ability to reduce the diffusion of copper ions than ECMM which had been subject to dialysis to remove soluble, low molecular weight components. The ‘insoluble’ fraction of ECMM for both species was more effective than the ‘soluble’ fraction at reducing the diffusion of copper ions. It is concluded that ECMM confers some protection to hyphae against the toxic effects of copper ions on growth in vivo and that this due to the binding of copper ions to both the polysaccharide and to low molecular weight components of the ECMM
D Vesentini, D J Dickinson, R J Murphy
Moisture content levels and decay of hemlock
1986 - IRG/WP 1287
As a model of decay conditions of wooden members in wooden houses, a decay test was set up in which samples of western hemlock (Tsuga heterophylla) under 4 moisture levels were examined. Each week the samples were weighed and if the weights indicated that their moisture contents were lower than the expected levels, distilled water was added. Every 8 weeks 3 samples from each condition were oven dried at 60°C for 48 hours, up to 48 weeks. After 48 weeks, 3 samples from each condition were oven dried every 16 weeks. The results obtained were as follows: After examining the samples for 96 weeks at 27°C, the mean weight loss of the hemlock samples kept at about 50-100% moisture content level was larger than those of the other levels. If the samples were dried every 8 weeks, the amount of decay in them was not significant. Decay was also not significant in the samples kept at approximately 20-30% moisture content level.
Influence of different fixation and ageing procedures on the leaching behaviour of copper from selected wood preservatives in laboratory trials
2003 - IRG/WP 03-20264
The paper focuses on the role of different parameters, such as fixation, sample size, wood species, and leaching in internationally standardized ageing procedures for wood preservatives from Europe, Japan and the United States. The leaching protocols used were EN 84, JIS K 1571 and AWPA E11 protocols. The wood species were Scots pine, Sugi and Southern Yellow Pine respectively. Three types of commercially important copper-based wood preservatives were used as model formulations, namely copper/copper-HDO, ammoniacal copper/quat and CCA. The most important factors determining the extent of copper leaching in the different lab trials were the sample size (volume/surface ratio) and the fixation conditions prior to leaching. On the other hand, the wood species and the leaching protocol itself were found to have only minor influence on the copper leaching rate in the test methods included in this study.
J Habicht, D Häntzschel, J Wittenzellner
New technique to analyze impregnation processes
1988 - IRG/WP 2304
Equipment has been developed to measure liquid flow in wood during impregnation processes. Basic principles of flow measurements using directly heated negative temperature coefficient thermistors, and some characteristics of the hardware developed are presented in this paper.
J P Hösli
Soil virulence tests using Scots pine sapwood
1973 - IRG/WP 222
Following the tests reported in Document No: IRG/WP/210, in which soils from different laboratories were investigated for virulence, supplementary tests have been carried out using Scots pine sapwood and an extended incubation period.
J K Carey, J G Savory
Types of decay observed in CCA-treated pine posts in horticultural situations in New Zealand
1984 - IRG/WP 1226
The few reported failures of 11-12-year-old horticultural posts in New Zealand in 1982 were caused by brown-rot. A subsequent survey of CCA-treated posts in all the major horticultural areas has revealed decay of many posts. A microscopic examination of these posts has shown decay by brown-rot, white-rot, soft-rot and bacteria. Several types of bacterial decay have been observed.
J A Drysdale, M E Hedley
International collaborative laboratory comparison of two wood preservatives against subterranean termites: Third update and first report
1996 - IRG/WP 96-10174
At the 24th annual meeting of IRG in Orlando, USA, in May 1993 an international subterranean termite laboratory bioassay to compare the various preferred termite protocols used by IRG termitologists was initiated. The author was nominated to co-ordinate this comparative laboratory evaluation of two wood preservatives, copper-chrome-arsenic (CCA) and copper naphthenate (Cu-Na) against the subterranean termites used as test termites in Australia, France, Japan, Thailand, United Kingdom and the Unites States of America. Solutions of these two wood preservatives were prepared and impregnated into Pinus radiata wood blocks to obtain loading of 0.0, 0.5, 1.0, 2.0 and 4.0 kg/m³ respectively. All preservative treatments were carried out at the Division of Forestry and Forest Products in Melbourne. The treated specimens were dispatched to the participating researchers who subjected these specimens to attack by their test termite species, and have now returned the specimens to Melbourne. This paper reports the amount of wood consumed and the mean mass loss (%) on both treated and untreated wood blocks by the termites in the various laboratory bioassays.
J R J French
Electrodialytic remediation of creosote and CCA treated timber wastes
2002 - IRG/WP 02-50190
There is a growing concern about the environmental issue of impregnated timber waste management, since an increase in the amount of waste of treated wood is expected over the next decades. Presently, no well-documented treatment technique is yet available for this type of waste. Alternative options concerning the disposal of treated wood are becoming more attractive to study, especially the ones that may promote its re-use. Inside this approach, the electrodialytic process (ED) seems a promising technique for removal of preservative chemicals from treated wood waste. The method uses a direct electric current and its effects in the matrix as the “cleaning agent”, combining the electrokinetic movement (mainly due to electromigration, but also electro-osmosis and electrophoresis), with the principle of electrodialysis. This work reports results from the application of the electrodialytic process to an out-of-service Portuguese creosote and CCA-treated Pinus pinaster Ait. railway sleeper and pole. The behaviour of the process is described and the main results discussed. The average removal rate, estimated in accordance with prEN 12490, for creosote from treated timber waste was around 40 %.. For CCA treated timber waste, experimental conditions that could optimise the process efficiency (e.g. current density, time) were studied. The highest removal rates obtained until now, in our studies, were 93 % of Cu, 95 % of Cr and 99 % of As for sawdust using 2.5 % oxalic acid (w/w) as the assisting agent. For CCA treated wood waste in the form of chips, the best removal rates obtained until now were 84 % of Cu, 91 % of Cr and 97 % of As.
E P Mateus, A B Ribeiro, L Ottosen
Fungicidal activity of some organic solvents, copper carboxylates and their complexes with 2-aminoethanol
1997 - IRG/WP 97-30136
We evaluated the activity of eight organic solvents against wood - rotting fungus Trametes versicolor in order to choose the most appropriate one for rapid screening tests of some copper(II) carboxylates and their adducts with 2-aminoethanol. Their activity against the selected fungus was classified in the following order: chloroform > N,N-dimethylformamide > acetonitrile > methanol > dimethyl sulfoxide > ethanol > acetone. The non-polar white spirit did not dissolve in the growth medium and the results could not be directly compared with the results for other solvents. As an appropriate solvent for screening of the tested copper(II) carboxylates, dimethyl sulfoxide (DMSO) was chosen. Minimal inhibitory concentration against Trametes versicolor of the screened carboxylates was in the concentration range of 1x10-4 to 1x10-3 mol/l. Coordinated amine ligands slightly, and not significantly, decreased fungicidal properties of the tested carboxylates.
M Petric, F Pohleven
Co-operative research project on L-joint testing. Sampling after 8 months exposure
1983 - IRG/WP 2208
It was anticipated in Document No IRG/WP/2192 that exposure of L-joints by the European co-operators would take place on 1 April 1983. Where L-joints were exposed at this time, sampling after 8 months exposure is due on 1 December 1983. The present document draws attention to relevant previous documents which describe the sampling methods to be adopted. It also provides Tables for recording the results.
J K Carey, A F Bravery
Comparison of the agar-block and soil-block methods used for evaluation of fungitoxic value of QAC and CCA wood preservatives
1994 - IRG/WP 94-20039
The modyfied agar-block and soil-block methods were used for comparing the fungitoxic value of QAC and CCA type preservatives against Coniophora puteana and Coniophora olivacea The mass loss and moisture contents of wood were analysed.
J Wazny, L J Cookson
An investigation of the effects of pre-steaming on the treatment of sawn spruce timber with Celcure A, a copper-chrome-arsenic preservative
1981 - IRG/WP 3150
Difficulties in the treatment of spruce using standard vacuum/pressure techniques with both water-borne and organic solvent preservatives are well known. We have evaluated the influence of steaming on treatability with a waterborne CCA preservative.
C R Coggins