Your search resulted in 247 documents. Displaying 25 entries per page.
Economical analysis of the chemicals used on remediation copper, chromium and arsenic from out of service CCA-treated utility poles in Turkey
2004 - IRG/WP 04-50217
There are 20.7 million hectare forested area in Turkey. However, the wood products supplies do not meet demand. One of the wooden products is the utility poles. In Turkey, impregnation of utility poles has been started since 1960's and 5 million utility poles have been used until today since then. Although life time of the utility poles may vary depending on climatic conditions, average service time of utility poles used in Turkey is about 25 years. Therefore, it is estimated that each year 200.000 m3 utility poles are out-of-service and they need to be replaced. In recent years, because of the unwanted effects of out-of-service CCA treated utility poles either during their storage or being recycled, there is a urgent needs to find a way removing Copper, Chrome and Arsenic from out-of-service CCA treated utility poles. For this purpose, many scientists have been studying on remediation of CCA treated wood. In this study, oleic acid, chromotropic acid and citric acid were used to remove Cu, Cr and Ar from CCA treated wood samples. The objective of this study is to determine the chemical that provides the maximum Cu, Cr and Ar removal from CCA treated wood as well as the cost effective one.
E D Gezer, D Toksoy, Ü C Yildiz
Analysis of tebuconazole in wood treated with Tanalith™ E
1999 - IRG/WP 99-20158
A simple gas chromatographic method for determining tebuconazole in Tanalith™ E treated wood is described. A two step sequential extraction procedure with methanol was used. Sample extracts were analysed without cleanup or concentration using capillary column GC with thermionic specific detection. The performance of the method was assessed using radiata pine (Pinus radiata) sapwood, radiata pine heartwood, and spotted gum (Corymbia citriodora) sapwood as substrates. Recoveries from fortified samples ranged from 97% to 103%. The precision of the method was assessed by analysing a number of actual treated wood samples over a range of retention levels, which produced relative standard deviations in the range of 3% to 8%.
D E Ferlazzo
The applicability of life cyle analysis and alternative methods in the wood preservation industry
1994 - IRG/WP 94-50023
In the Netherlands, several case studies have been performed using the life cycle analysis method (LCA). This type of research is aimed at an inventory and classification (sometimes including also evaluation) of the environmental impacts of a product, from the raw material to waste stage ("cradle to grave" approach). In a LCA each environmental impact is assessed in terms of, for example, mass of raw material use (kg), energy consumption (MJ), emissions (COx, NOX, SOx, etc.) and final waste (in kg). The critical point in an LCA is the definition of comparable "functional units" for similar products made of different materials with different service lifes. As the LCA method has often proved to be very complex, lime-consuming, expensive and difficult to interpret and translate into practically usefull results, alternative methods are developed. Three methods are described and compared on the basis of various examples. It is hoped that this may be of use as a starting point for further discussion on the suitability of applying the LCA on (preservative treated) timber products.
P Esser, J Cramer
Utilization of curcumin for detection of presence of boron in wood
1982 - IRG/WP 3191
It has been shown that curcumin is not a reliable reagent for detecting boron in wood that has been attacked by fungi
Results of chemical analyses in the field of wood preservation in the Bundesanstalt für Materialprüfung
1973 - IRG/WP 321
The results of qualitative and quantitative chemical analyses of wood preservatives are often the basis for evaluating the various works in the field of wood preservation. In the past 10 to 15 years a number of such works was carried out in the Bundesanstalt fur Materialprüfung, Berlin-Dahlem, dealing with the identification and effectiveness of wood preservatives and with methods of wood preservation. Fundamental realisations were made which will be summarised below. It seems advisable to differentiate between inorganic and organic chemical wood preservatives and methods of analyses. These are two distinct fields which differ also with regard to the analytical techniques applied.
H J Petrowitz
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
Penetration analysis of two common bamboo species - borak and jawa of Bangladesh
2002 - IRG/WP 02-40247
Preservative treatment of two bamboo species, namely borak (Bambusa balcooa Roxb.) and jawa (Bambusa salarkhanii Alam) was carried out with chromated copper boron (CCB) preservative by dipping method. The variation in preservative penetration between the two different species was determined. It was found that preservative penetrates into borak quicker than into jawa and easier into air-dried bamboo than into green one.
M O Hannan, A K Lahiry, N M Islam
Draft economic plan for the IRG for the period 1993-1997
1993 - IRG/WP 93-60004
Finite element analysis of boron diffusion in wooden poles
2003 - IRG/WP 03-40263
The problem of describing the migration of dissolved boron in wood is treated with special reference to the commonly used remedial treatment of wooden poles. The governing equations are derived and discussed together with some of the material parameters required. The equations are solved by the finite element method and finally, results showing the effect of different treatment strategies are presented.
K Krabbenhøft, P Hoffmeyer, C G Bechgaard, L Damkilde
Conforming to european standards for preservative-treated timber: Specifying with confidence
2000 - IRG/WP 00-20194
A four-year collaborative study between four industrial partners and BRE has assessed timber treated by current UK industrial practices in the light of current European Standards. Data were collected for CCA and creosote treated timber components, and compared with the requirements laid out in EN351-1 and -2. A number of difficulties were encountered that have been described in previous IRG papers (98-20150, 99-20156), such as the poor reproducibility of chemical analyses and variable timber density. This paper describes the conclusions of our collaboration, focusing on the application of the findings and how to overcome any difficulties encountered. The data collected allowed the calculation of figures that have been submitted for inclusion into the UK's proposed national code for preservative-treated timber (DD239). An example is the recommendation of new minimum retention figures for creosote-treated commodities. This paper describes the factors that will enable UK specifiers to use the European Standards with confidence and greater understanding of how they map onto traditional methods of specification. In addition valuable lessons have been learnt applicable to the industry world wide.
E D Suttie, R J Orsler
Quantitative determination of Chromium: A comparison of three instruments
1995 - IRG/WP 95-50053
A comparison is made between three instruments for measuring levels of chromium in the leachate of copper-chrome-arsenic (CCA) treated timber. These include an atomic absorption spectrophotometer, an inductively coupled plasma spectrometer and the RQflexâ. The RQflexâ is a new hand-held instrument which measures chromium by dipping a ReflectoquantÒ strip into the leachate and inserting the strip into the RQflexâ. Readings are determined reflectometrically following a reaction between chrome and the Reflectoquantâ strip. It provides an inexpensive and quick technique which is used in this paper to determine the degree of preservative fixation prior to the removal of CCA treated timber from drip pads of wood treatment sites. The results indicate that RQflexâ is a suitable instrument for the rapid assessment of chromium levels in rain wash off from treated timber. A comparison is given of the economics and accuracy of the instruments for measuring chromium.
S Walley, P R S Cobham, P Vinden
Electron microscopic detection and chemical analysis of three-lamellar structures in wood-destroying fungi
1984 - IRG/WP 1240
In the course of transmission electron microscopical investigations of pine wood decay by various brown- and white-rot fungi extracellular three-lamellar structures (TLS) formed by the fungi were found in specimens stained with ruthenium red. These structures occured in the lumen of the wood cell surrounding the hypha at the outermost layer of the fungal cell wall. In the course of the investigations these structures were also detected in fungi cultivated with glucose on a rotary shaker, where they showed forms similar to tubuli and vesicles. The three-lamellar structures formed by the white-rot fungus Sporotrichum pulverulentum, which were contained in the outermost cell wall layer, were isolated by disintegration of the fungal pellet and subsequent digestion of the fungal cell wall by snail enzyme. It was found that these structures are resistant to the enzymatic digestion and are composed of 80 to 90% carbohydrates, mainly consisting of glucose monomeres, 5 to 10% proteins, containing 5 fractions with molecular weights between 30000 and 200000, and finally 5 to 10% lipids which do not contain any phospholipid.
R Foisner, K Messner, H Stachelberger, M Röhr
Observations on the failure of anti-sapstain treated timber under non-drying conditions
1990 - IRG/WP 1437
A range of bacteria and yeasts were isolated from antisapstain treated timber and fresh sawdust. Solution samples containing 100 ppm of TCMTB in a nutrient medium were inoculated with these organisms and incubated at 25°C for 5 days. The levels of TCMTB remaining in solution were determined by HPLC analysis after this time. Results indicated high losses of active ingredient for a range of organisms. These results suggest that active biodetoxification of organic biocides could occur in a short period of time during storage of antisapstain treated timber under favourable conditions. The implications of these results are discussed.
G R Williams
Detection of defects in standing poles by X-ray techniques
1980 - IRG/WP 2132
The application of X-ray techniques to wood pole inspection procedures has been evaluated. Internal defects were accurately identified using X-ray inspection methods. These methods and their possible influence on the safety and economic aspects of wood pale utilization are discussed.
W D Gardner, R S Johnstone, W Pitt
Collaborative field experiment: Analysis of copper and chromium in stakes of the four reference timbers
1982 - IRG/WP 3213
The stakes analysed belong to the Swedish set of the four reference timbers of the collaborative field experiment (Document No: IRG/WP/367). Before the field exposure 60 mm were cut off the end of each stake. This was done in order to be able to carry out chemical analyses as well as different types of testing. Some of the material has been used in softrot tests (Document No: IRG/WP/1151).
Collaborative soft rot tests: 2nd interim report
1975 - IRG/WP 258
J G Savory, J K Carey
A bibliography of organic solvent-based wood preservatives
1973 - IRG/WP 322
Comparative studies on the distribution of lignin and CCA elements in birch using electron microscopic X-ray microanalysis
1987 - IRG/WP 1328
The microdistribution of metal preservatives in treated wood has received considerable research over the last two decades. Despite this, little effort seems to have been made to try and correlate the distribution of CCA elements with respect to naturally occurring wood cell wall components in wood. In the present preliminary study an attempt is made to relate the distribution of lignin in-situ with that of CCA elements. For the study matched samples of Betula verrucosa were first either mercurized to specifically label the lignin or vacuum impregnated with a commercial 2% K33 CCA preservative solution. Thereafter using SEM-EDXA, the relative distribution of labelled lignin and CCA elements were compared for both different cell types and cell wall regions. Results showed the relative microdistribution of CCA to follow closely that of the lignin distribution. Regions showing high lignin levels showed high CCA levels and vice-versa. Highest CCA and lignin levels were recorded in the vessel, fibre and ray middle lamella cell corners regions while the lowest levels were detected in the fibre (S2) secondary walls. Both the low lignin level (and syringyl type) and CCA uptake in fibre S2 walls would seem in close agreement with the known high susceptibility of these elements to soft rot attack in both treated and untreated birch. Comparisons made between the lignin content of the S2 layer for birch fibres and other known soft rot resistant species (e.g. Alstonia scholaris) showed great differences, with the latter showing much higher lignin (ca 3x) levels.
G F Daniel, T Nilsson
Ultrastructural and TEM-EDAX studies on the degradation of CCA treated radiata pine by tunnelling bacteria
1985 - IRG/WP 1260
An ultrastructural study was carried out on bacterial attacked Pinus radiata stakes treated with a high level (24.7 kg/m³) of Tanalith NCA preservative. The purpose of the investigation was to determine whether the organism possessed intracellular and/or extracellular detoxification mechanisms in order to overcome the high levels of copper, chrome and arsenic present within the wood fibre walls. Correlated T.E.M. and T.E.M.-EDAX studies showed most of the preservative elements to remain outside the bacteria associated with bacterial tunnel wall and cross-wall extracellular secretions. T.E.M.-EDAX showed the levels of preservative elements present in the tunnel walls and cross walls to often greatly exceel that recorded in neighbouring S2 cell wall regions, while studies on the bacteria showed that only copper and very low levels of chromium and arsenic had entered the cells. Observations suggested that the metals found within the cells were associated with electron-dense deposits or inclusions within the nuclear region or cell cytoplasm, the deposits often containing high levels of phosphorus and calcium together with lesser levels of other cations. The study also provided evidence for the direct visualisation of CCA preservative elements within fibre walls using T.E.M. without any form of secondary chemical enhancing, and in addition, considerable new information on the nature and structure of the single celled, Gram-negative, motile bacteria involved in the decay.
G F Daniel, T Nilsson
Moulds and indoor climate in Denmark
2003 - IRG/WP 03-10488
Just like in many other countries after the oil crisis in 1972 Danish houses were tightened with the result that the relative air humidity rose considerably. The Ministry of Energy also demanded a lowering of the indoor temperature from 25°C to 20°C with the result that the relative air humidity rose even more. According to the latest survey 10% of Danish buildings are infected with moulds. Moulds occur in the indoor environment e.g. when humid air condensates on cold outer walls or in connection with water damage which is insufficiently dried out. In our analyses we always try to determine moulds both to genus and species. During our surveys in August 2001 and February 2002 we found 50 different species of moulds in Danish houses. The species Penicillium chrysogenum was dominating in both spring and autumn. Aspergillus versicolor was also present in spring and autumn but in smaller numbers. Cladosporium herbarum was most common during autumn. Stachybotrys chartarum was rather rare, maybe because it is closely connected to gypsum boards. It is very important to identify the moulds to species which is shown by the following case study. In a house where the sewer had been punctured in connection with establishment of district heating, 150 cubic metres of water had poured into the crawl space. We were called in by the occupant because she felt ill and there was a strong mouldy smell. We immediately asked her to move, with the result that her health improved almost instantly. She was so sensible that even the delivery of mail in her mailbox made her ill. A blood-test showed that she was sensitised to Trichoderma viride and Penicillium chrysogenum. The latter was found in large amounts in her house. We know that it is now possible to repair the house so that non-sensitised persons will be able to live there, but not the former occupant who will react to even small traces of allergen which are still there. After the repair we have different methods of quality control. It is now evident that some remedies and methods will kill the spores others the mycelium and yet others both. Some methods have a lasting effect, others do not. Our methods of quality control are either contact-samples with Petri dishes where mould colonies are counted and identified to species or a test for ATP or the Mycometer-test where the enzyme β-N-acetylhexosaminidase specific to fungi is measured. The Petri dish method measures the number of living spores, while the two other methods measure the amount of mycelium. However it seems that ATP in the mycelium is broken down faster than the enzyme measured by the Mycometer-test. Therefore it becomes difficult to decide whether the mycelium is living, partly dead or completely dead, when the repair work is going to be approved.
J Bech-Andersen, S A Elborne
X-ray analysis of selected anatomical structures in copper/chrome/arsenic treated wood
1973 - IRG/WP 320
Application of analytical electron microscopy to problems in wood preservation has been very limited. Indeed, less than ten workers appear to have published their results using the technique, and of these' only two papers deal with energy dispersion procedures in the scanning electron microscope; the others employ the more familiar wavelength dispersive methods of the electron probe.
Exposure monitoring of creosote vapors
1989 - IRG/WP 3511
Creosote oils contain hundreds of compounds. During impregnation and handling of treated wood the main component in the vapors released in air is naphthalene. Other main components are alkyl naphthalenes, indene, phenol and its methyl derivatives, benzothiophene, diphenyl, acenaphthalene and fluorene. In the measurement of creosote vapors, naphthalene can be used as an indicator agent. One of the major urinary metabolites of naphthalene is 1-naphthol. To explore the relation between naphthalene concentration in the air and 1-naphthol in the urine of exposed workers we monitored air concentrations and collected urine samples from six men over a working week. 1-Naphthol concentrations in urine samples were analyzed by GC as a pentafluorobenzylbromide derivative. The average concentration of 1-naphthol in the Monday morning samples was 0.1 mg/l, in the Monday afternoon 3.1 mg/l, in the Friday morning 0.4 mg/l and in the Friday afternoon 2.9 mg/l.
P Heikkilä, M Loutamo, V Riihimäki, M Romo
How best to specify retentions of preservative treatments: kg/m3 or % (m/m)
1998 - IRG/WP 98-20151
When specifying treatments according to the European Standard EN 351-1, retentions in the analytical zone are based on the amount of product found to be effective in biological tests; this is expressed in terms of the retention of the product per unit volume (kg/m3) for penetrating treatments and per unit area (g/m2) for superficial treatments. However, to check whether the retentions have been achieved, chemical analyses are carried out where the results are initially expressed as% (m/m). In converting results from% (m/m) to kg/m3 , a value for the density of the wood must be applied that is closely associated with the sample of wood taken for chemical analysis. This is difficult to achieve and it has been suggested that the results from biological tests and the associated retention values be expressed in% (m/m) to avoid this difficulty. For treatments applied by penetrating treatment processes, expression of the retention of a wood preservative product as% (m/m) reduces error. The initial dry weight of the test specimens affects the relationship between retentions expressed as kg/m3 and% (m/m) because heavier test specimens take up less treating solution. The change in the method of expressing the retention of a wood preservative product to% (m/m) is unlikely to have any major effect on the results within a wood species. However, the change reduces the difference between the retentions which are effective in Scots pine sapwood and beech against attack by Coriolus versicolor. Use of% (m/m) instead of g/m2 offers no advantages for superficial treatment processes.
J K Carey
Analysis of creosote posts after 40 years of exposure
1994 - IRG/WP 94-50035
In the early 1950s The Western European Institute for Wood Preservation (WEI) started a program for testing creosote and salt treated posts in three exposure sites in Europe. Of these only the site in Simlångsdalen in south western Sweden remains today. The purpose with this investigation was to demonstrate which creosote components are still retained in the posts after 40 years of exposure and which components have migrated or evaporated. Three posts, impregnated with three different creosotes, from the site in Simlångsdalen have been studied. The retention, composition and distribution of creosote in the posts have been determined and compared with data on the original creosote. After 40 years of exposure creosote loss is greatest in the post impregnated with creosote containing the highest fraction of low-boiling constituents. The loss is greatest in the top sections of all three posts. The concentrations of low-boiling compounds (b.p. < 270°C), e.g. naphthalene and 2-methylnaphthalene are very low. The residual creosotcs have the greatest percentage of high-boiling constituents (> 315°C), especially phenanthrene and anthracene (b.p. 340°C). The soil close to those posts which were "over-loaded" with creosote during the treatment process, contains increased concentrations primarily of the heavier components fluoranthene, pyrene and chrysene. The small number of posts analyzed limits the possibility to generalize the conclusions.
G Bergqvist, S Holmroos