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Removal of heavy metals from treated wood using biological methods
2005 - IRG/WP 05-50226
Heavy metals were removed from wood treated with copper based preservatives using brown-rot fungus Fomitopsis palustris. The amount of effective elements removed by treatment methods was examined. The relationship between oxalic acid concentration and the amount of heavy metals removed from each treated wood was also investigated. The relationship between fungus weight and removal rate was also included. The removal rates of heavy metals were examined at the different mass of chips and different retention rates and different specimen sizes. Effective element removal rate of preservative-treated wood was compared with different cultivation methods. Based on the results of lab-scale experiment, an air lifting bioreactor was employed for its large-scale operation. The efficiency of bioreactor was evaluated.
Dong-won Son, Dong-heub Lee


Protection of Ochroma pyramidale from fungal decay with N,N-napthaloylhyroxylamine
1998 - IRG/WP 98-30182
Fungal decay of wood in service results in billions of dollars (U.S.) in losses annually. Recent environmental restrictions, both U.S. and international, are limiting and eliminating the use of broad-spectrum, heavy metal biocides for wood preservation. Restrictions result primarily from problems with disposal. New wood preservatives need to be developed and tested which specifically target key elements in the sequence of fungal decay mechanisms. Our laboratory has been experimenting with chemicals which inhibit pectin hydrolysis during incipient brown-rot and white-rot decay in southern pine sapwood (Inter. Biodeter. Biodegrad. 39:103). In the present paper these results are extended to include the tropical hardwood Ochroma pyramidale (balsa). Balsa blocks (24x18x12mm) were exposed to two brown-rot fungi and one white-rot fungus in ASTM soil block tests for 10 weeks. CCA (6.4 km/m3 ) was compared with the calcium binding agent N,N-napthaloylhydroxylamine (NHA; 1.6, 3.2 & 6.4 km/m3 ) in leached and unleached blocks. CCA protected balsa with minimal weight loss (> 7.4%) with no leaching effects. NHA (6.4 km/m3 ) protected balsa (0.3-1.2%) weight loss but leaching raised the weight losses to 25% with the brown-rot fungus Tyromyces palustris. We conclude that NHA can protect balsa against G. trabeum and T. versicolor with comparable efficiency to CCA (leached and unleached) but not T. palustris.
F Green III, T L Highley


Effect of EDTA on removal of CCA from treated wood
2002 - IRG/WP 02-50182
Since substantial amounts of chromated copper arsenate (CCA) remain in the wood for many years, the disposal of CCA-treated wood causes escalating environmental concerns. Additionally, wood waste is generated when treated wood is put into service, for which environmentally benign disposal technologies need to be developed. Novel approaches to remove copper, chromium, and arsenic from CCA-treated waste wood are needed to overcome such environmental concerns. Acid extraction, one of the most extensively used methods, has been studied by several researchers for removal of copper, chromium, and arsenic from CCA-treated wood. In this study, EDTA (ethylenediaminetetraacetic acid) extraction of copper, chromium, and arsenic from CCA- treated wood was evaluated using batch-leaching experiments. EDTA is one of the most common chelator used to bind the metal ions in extremely stable complexes in heavy metal contaminated soils and thus to remediate such substrates. EDTA forms water soluble complexes with many metal ions and it is used to release for the various metals. In the study, chips and sawdust containing CCA were processed by EDTA extraction to remove the metal elements present in the form of oxides. CCA-treated wood samples were extracted with four different concentrations of EDTA (0.0, 0.01, 0.1, and 1.0%) for 4 and 24 hours at room temperature. Exposing CCA-treated chips and sawdust to EDTA extraction enhanced removal of CCA components compared to extraction by deionized water. Grinding CCA-treated wood chips into 40-mesh sawdust provided greater access to and release of CCA components. Extraction with 1% EDTA solution for 24 h released 60% copper, 13% chromium, and 25% arsenic from treated chips. EDTA extraction of treated sawdust samples resulted in 93% copper, 36% chromium, and 38% arsenic release. The pH of EDTA solutions ranged from 2.2 to 3.2, providing acid conditions, which facilitate release of copper element. The results suggest that EDTA extraction removes significant quantities of copper from CCA-treated wood. Thus, EDTA could be important in the remediation of wood waste treated with the newest formulations of organometallic copper compounds and other water-borne wood preservatives containing copper.
S N Kartal


Bioassays for rapid assessment of heavy metal toxicity in seawater
1998 - IRG/WP 98-50112
In evaluating the effect of CCA leachate on the establishment of fouling communities on wood exposed in the sea, three organisms were assessed as biological indicators of heavy metal toxicity. These were two macroalgae, Fucus serratus and Undaria pinnatifida. and the motile protist thraustochytrid, Schizochytrium aggregatum. The choice of these organisms for the tests carried out was based on the need for rapid methodology and relative simplicity in their isolation and cultivation. The two test algae were collected locally on the south coast of England, cleaned of surface contamination and prepared for release of their respective reproductive spore types. Toxic effects of a range of concentrations of CCA leachate were then measured in terms of spore/zygote germination using simple microscopic observations after 3-4 days incubation. The thraustochytrid was obtained from stock cultures held at the University of Portsmouth. The zoosporic stage in the life cycle of this organism was used to indicate the toxic effects of copper ions in seawater-based medium by measuring loss in motility over a 20 minute period. Data were collected using motion analysis equipment. Subsequent recovery of zoospores after 1 hour exposure to different copper levels was determined. Non-motile stages of the life cycle of thraustochytrid isolates were also used to determine copper toxicity. Tolerance of these organisms to heavy metals in CCA leachates will be discussed.
C J Brown, R L Fletcher, R A Eaton


Equilibrium distribution of toxic elements in the burning of impregnated wood
2001 - IRG/WP 01-50172
The current work focuses on predicting the behavior of arsenic, chromium, and copper in the burning of impregnated wood. A theoretical method is used to study the chemistry of the system, with special interest directed towards the vaporization tendency of the potentially toxic elements. The core of the study is the global equilibrium analysis that simultaneously takes into consideration all chemical reactions. The results of the present study indicate that chromium and copper are unlikely to volatilize at combustion temperatures. Arsenic appears to be more volatile. Nevertheless, the prediction showed that it may be captured by calcium of the wood ash, and small amounts are likely to dissolve in the slag-phase of the ash. It may also form non-volatile compounds with magnesium, copper, and chromium and other elements of the impregnated wood, which efficiently hinders its emissions as gaseous species.
K Sandelin, R Backman


Environmental fate of copper-based wood preservatives in different soil substrates - Part 2: Study of the metal sorption and migration potential under simulated rainfall
1998 - IRG/WP 98-50101-21 b
In order to examine the potential environmental impact of spillages of the saltborne wood preservative CCA in treatment plants, four large scale experiments are set-up so as to follow the water transport and ion mobility in various field soils. A plastic container is filled with a sand, silt, clay and potting soil, made up at their respective bulk density and wetted to a given moisture content. Using a rain simulator on top, a homogeneous spillage of a ready-to-use CCA solution is applied, followed by a rainfall simulation after 3 days and a 3 weeks redistribution period. Soil augers that are taken prior to each new perturbance reveal the distribution and migration pattern of the heavy metals. Copper and arsenic are strongly adsorbed in the upper soil layers, depending on the soil characteristics. Chromium, however, is percolated easily through the soil column and is readily extractable from the soil using pure water.
G M F Van Eetvelde, R Hartmann, J M Mwangi, H S Öztürk, M Stevens


Fungal biodegradation of CCA-treated wood wastes
2011 - IRG/WP 10-50276
Fungal biodegradation could be employed as a pretreatment method to alleviate problems caused by landfill disposal of CCA-treated wood wastes (e.g. a shortage of landfill space and a release of leacheate). It could be used to decrease the volume of waste and to remove metals from waste simultaneously. We have screened hundreds of decay fungi, including fungi isolated from CCA-treated wood in service, in search of the CCA-tolerant fungal isolates. The decay capacity of the tolerant isolates was determined by the AWPA method, and the amount of CCA components removed during decay process was also investigated. A total of five isolates was confirmed that they have notable capacity to degrade treated wood and to remove CCA components. Among them, Crustoderma sp. KUC8611 effectively decayed treated wood causing mass loss of up to 60%. Biodegradation with F. palustris showed extensive leaching of chromium trioxide and arsenic pentoxide (up to 77%), but only moderate leaching of copper oxide (up to 32%). It was confirmed that these high removal capacity of chromium trioxide and arsenic pentoxide had high logarithm regression relationships with oxalic acid produced in decayed wood. In this paper, we discuss the potential of fungal biodegradation of CCA-treated wood wastes based on our relevant research results.
Gyu-Hyeok Kim, Yong-Seok Choi, Jae-Jin Kim


Laboratory study of toxicity or tolerance of CCA preservative and heavy metal constituents copper, chromium and arsenic to Malaysian tropical fungi
2011 - IRG/WP 11-30579
CCA preservative and its constituent heavy metal tolerance and toxicity to 3 Malaysian isolates Phialophora fastigiata (soft rot fungus), Paecilomyces variotii (mould fungus) and an unidentified white rot Basidiomycete, was investigated by the modified ‘Strange-Smith’ agar-well-plate technique with 1.6% CCA concentration and the malt-agar-plate bioassay technique with a range of CCA and constituent metal salt concentrations of 0.0024 – 5%m/m. Daily linear hyphal extension was measured between 6 and 22 days depending on relative fungal growth rates. The slow growing Phialophora fastigiata sustained mean daily hyphal growth (mm) at relatively higher concentrations of CCA preservative (toxic limits: 0.24 – 0.48%m/m) and their heavy metal constituents (copper-salt: 5.0 – 10.0%m/m; chromium-salt: 0.076 – 0.24%m/m) than the faster growing mould isolate Paecilomyces variotii (CCA: 0.019 – 0.076%m/m; chromium-salt: 0.076 – 0.24%m/m) and the white rot Basidiomycete of intermediate growth rate (CCA: 0.076 – 0.24%m/m; copper-salt: 0.076 – 0.24%m/m; chromium-salt: 0.0095 – 0.019%m/m) except for arsenic-salt (Phialophora fastigiata: 0.076 – 0.24%m/m; Paecilomyces variotii: 0.48 – 0.95%m/m; Basidiomycete: 0.24 – 0.48%m/m). The results showing varying efficacies (toxicity versus tolerance) in vitro of CCA and their metal constituents between these fungi can have implications to ground-contact wood protection capabilities of CCA.
A H H Wong, T Mark Venås, N Morsing, C C L Tan, P K F Chong


Scale-up of a chemical process for copper-based preservative-treated wood wastes recycling
2012 - IRG/WP 12-50286
In recent years, the development of appropriate wood waste disposal options has been encouraged by severe regulations and expensive fees associated with wastes landfilling or burning. An efficient and economically attractive leaching process was developed at laboratory scale (200 mL) for CCA-, ACQ- and CA-treated wood wastes recycling. This leaching process consisted of three leaching steps of 2 hours each, at 75°C with a sulfuric acid concentration at 9.8 g/L followed by three water-rinsing steps. The objective of this study was to investigate a possible application of this process to various mixtures of copper-based preservatives-treated wood wastes at pilot scale (80 L). The mixture of copper-based preservative-treated wood wastes was defined in order to represent wood waste stream evolution in the next decades. At the end of the leaching process, more than 98% of arsenic, 89% of chromium and 99% of copper were removed from a mixture of treated wood. Metal concentrations of the effluents produced during leaching steps were higher than regulations for effluents discharge in urban sewer. Leachate treatment by precipitation-coagulation was highly efficient and achieved more than 98% metal removal. The remaining arsenic, chromium and copper concentrations of the final effluents satisfied Quebec City municipal effluent discharge regulations. Chemicals consumption (sulfuric acid, ferric chloride, sodium hydroxide) depends of the mixture composition of treated wood. Remediation costs (total direct, indirect and general costs) ranged from $140 to $180 per metric ton of treated wood (ttw) depending on percentage of CCA-treated wood in the mixture. The use of wood residue for energy production represents an operating income estimated at $155/ttw (considering an energetic value of $13 per GJ).
L Coudert, L Gastonguay, J F Blais, G Mercier, P Cooper, P Morris, A Janin, N Reynier


Effect of silver nanoparticles on the rate of heat transfer to the core of the medium-density fiberboard mat
2014 - IRG/WP 14-40653
Effect of silver nanoparticles on the rate of heat transferred to the core section of medium-density fiberboard (MDF) mat was studied here. A 400 ppm aqueous nanosilver suspension was used at three consumption levels of 100, 150, and 200 mL/kg based on the weight of dry wood fibers; the results were then compared with the control MDF panels. The size range of silver nanoparticles was 30-80 nm. Results showed that the uniform and even dispersion of nanoparticles throughout the MDF-matrix significantly contributed to the faster transfer of heat to the core section. As to the loss of mat water content after the first 3 – 4 minutes under the hot press, the core temperature slightly decreased in the control panels. However, heat-transferring property of silver nanoparticles contributed in keeping the core temperature rather constant in the NS150 and 200 treatments. As to the de-polymerization of part of the resin in the surface layers of the mat due to the rapid absorption of heat from hot plates by the nanoparticles, it can be concluded that the optimum nano-suspension content should not necessarily be the highest one.
H Reza Taghiyari, O Schmidt, E Bari, P M Tahir, A Karimi, P Nouri, A Jahangiri


Possible regulatory status of treated wood waste and implications
1998 - IRG/WP 98-50101-07
In relation to the European Community or the French regulations, treated wood waste can get two different regulatory status: <<recycled product or fuel>> or <<waste>>. Then, into the waste status, two categories are possible for these residues: <<domestic waste and assimilated>> or <<hazardous waste>>. These different status and categories are important for the environmental issue of treated wood waste management. But they also can have strong economical implications, linked to the waste management cost on one hand and on the materials image on the other hand. On the basis of the EC regulations, up to now, no treated wood waste is namely quoted as <<hazardous waste>>. However, through the classification criteria defined by different EC directives, creosote or heavy metals treated wood waste could be to considered that way. The technical arguments for such a classification and the practical implications are discussed.
G Deroubaix


Temperature influence on the growing velocity and cellulolytic activities of Poria placenta strains from several locations
1986 - IRG/WP 2263
The differences observed on the FPRL 280 Poria Placenta strain at several Research European Laboratories for determining up the fungicide effectiveness of wood preservative has carry us to do a comparative study about the cellulolytic activity and growth velocity of each of this strains at different temperatures (22, 24 and 28°C). The results show significative differences when the temperature is changed.
A M Navarrete, M T De Troya


Monographic card on Antrodia serialis
1984 - IRG/WP 1145
G Seehan


Research on the effects of wood preservatives on the physical and mechanical properties of Iranian beech (Fagus orientalis Lipsky)
1985 - IRG/WP 3351
This research work was conducted with the aim of using preservatives such as Basilit and Wolman Salts with Iranian beech and to study any physical and mechanical changes these might have on the beech species of Iran. Samples were divided into three groups; one group were used as untreated controls, the second group was treated with Basilit and the third group was treated with Wolmanit. Results obtained according to the AFNOR French system of standards were: (1) After 140 days the moisture content of each group had reached 7.3%. (2) Samples with Wolmanit absorbed twice as much as those with Basilit and the two groups has some differences in specific gravity. (3) The volumetric shrinkage of wood preserved with Wolmanit was one fifth of that treated with Basilit. (4) In bending tests the samples treated with Wolmanit had more strength up to point of rupture than those preserved with Basilit. (5) The modulus of elasticity was more in samples preserved with Basilit than in those preserved with Wolmanit. (6) In compression parallel to the grain the samples impregnated with Basilit had more resistance than in those impregnated with Wolmanit. (7) In tension tests, the samples preserved with Basilit were stronger than those treated with Wolmanit. (8) In impact bending tests, the Basilit samples were stronger than the the Wolmanit ones. (9) In hardness tests, the resistance to indentation was less with the samples treated with Basilit than with those treated with Wolmanit; the Basilit seems to make the wood softer and from this result this type of treated wood could be recommended for use by carpenters and in woodworking shops.
P Niloufari


Effect of fatty acid removal on treatability of Douglas-fir
1993 - IRG/WP 93-40008
Treatment of Douglas-fir with chromated-copper-arsenate (CCA) poses a major challenge. Several hypotheses based on the anatomical aspects as well as chemical reactivity of the preservative formulations with cell wall constituents and deposits have been proposed. Techniques to prevent pit aspiration or slow fixation reactions have, however, not significantly improved treatment. The presence of high molecular weight fatty acids have been reported to be responsible for higher hydrophobicity in some wood species. These acids can react with Cu+2/Cr+3 ions to form insoluble metallic soaps, thereby immobilizing Cu/Cr and increasing wood hydrophobicity by a mechanism similar to that employed in paper sizing. The effect of fatty acids on treatability was explored by removing these components via several extraction methods. In general, extracted wood had higher gross solution absorptions and chemical retentions, but preservative penetration was largely unaffected. The results suggest that removal or disruption of fatty acids can improve treatability of Douglas-fir heartwood.
S Kumar, J J Morrell


The effect of sapwood on the rate of deterioration of fence posts
1986 - IRG/WP 1277
In order to evaluate the effect of the presence of sapwood on the rate of deterioration of fence posts, 30 specimens with and without sapwood of Eucalyptus citriodora, Eucalyptus paniculata, Eucalyptus saligna and Eucalyptus tereticornis were exposed in three test sites in the State of São Paulo, Brazil. The results of the inspection carried out in 1985, after 5 years of exposure, are reported in the present paper.
M S Cavalcante, G A C Lopez, E S F Mucci, R G Montagna


Report on the monographic card on Coriolus versicolor
1972 - IRG/WP 111
C Jacquiot


Report on the status of collaborative experiments within the Sub-group on Basidiomycete tests
1983 - IRG/WP 2194
This report summarises the results of co-operative work carried out within the Sub-Group on Basidiomycete tests up to December 1982. The principle findings are recorded in the Conclusions Section. Work intended between IRG-13 in Turkey and IRG-14 in Australia is cited under Future Programme. An Annex provides a response sheet for existing and new participants to notify their contributions.
A F Bravery


Non-enzymatic Gloeophyllum trabeum decay mechanisms: Further study
2001 - IRG/WP 01-10395
Information will be presented on the mechanisms involved in, and potential application of, non-enzymatic wood decay by brown rot decay fungi. Specifically, the hypothesized role of low molecular weight phenolate derivatives will be discussed in relation to non-enzymatic degradation of wood. The mechanism of binding of iron by cellulose, and binding and reduction of iron by fungal derivatives and model compounds is examined. Positive and negative aspects of potential application of these compounds in the generation of free radicals will be discussed.
B Goodell, J Jellison


Differences in feeding activity among colonies of Formosan subterranean termite Coptotermes formosanus Shiraki
1983 - IRG/WP 1202
Feeding activities of 7 colonies of the Formosan subterranean termite, Coptotermes formosanus Shiraki, were examined. Wood-consumption rates among colonies differed significantly, ranging from 23.80-78.48 mg/g/day. This large intraspecific variation raised a question of whether differences in feeding activity reported for other termite species were due to interspecific differences. When rates were expressed as mg wood consumed by one g termite per day (mg/g/day), termites of larger body weight appeared to consume less wood. This negative correlation, however, was not significant when rates were expressed as mg wood consumed by an individual per day (mg/worker/day).
N-Y Su, J P La Fage


Development of novel techniques for evaluating the feeding rate of Limnoria lignorum with specific reference to temperature influences
1999 - IRG/WP 99-10325
The faecal pellet production of Limnoria lignorum placed into repli-dish chambers containing seawater and a small chip of untreated Corsican pine (Pinus nigra) was observed. The repli-dishes were kept at a range of constant temperatures between 10 and 25°C and the number of faecal pellets produced by each of the animals was monitored. It was found that faecal pellet length generally increased with gut length and that temperature had no effect on the faecal pellet length. There was considerable variation in faecal pellet production rates, both from day to day for any particular animal and from animal to animal. Faecal pellet production rate was generally highest between 15 and 21°C and decreased above 22°C. The production of faecal pellets tended to decrease during moulting. Gut passages per day increased from 1.1 at 13°C to 3.4 at 21°C followed by a decrease to 1.6 at 25°C.
A Praël, S M Cragg, R A Eaton


Molecular studies on isolates of Serpula lacrymans
1989 - IRG/WP 1421
The major protein species present in detergent extracts of 14 different Serpula lacrymans isolates have been compared, by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), with a standard strain, viz. Serpula lacrymans FPRL 12C. Following silver staining of SDS gels the major protein species identified in 12 isolates were similar to those found in the standard strain. However differences were found when the final two isolates were compared with FPRL 12C, both isolates had extra molecular species not present in 12C and both were lacking some present in the standard strain. Comparison of the protein species identified in Serpula lacrymans isolates with those identified in extracts of other fungal organisms, viz. brown and white rot causing basidiomycetes and non-basidiomycetes indicated that the Serpula isolates were more similar to each other than to other organisms. Some molecular differences could be identified when individual isolates were cultured on different media, i.e. liquid culture or agar, only minor differences were seen when individual isolates were subcultured. These results indicate that whilst care must be taken to ensure as near identical conditions as possible for culture of organisms if their molecular species are to be compared by SDS-PAGE and silver staining, consistent results can be obtained using this technique. The technique may therefore offer a method of distinguishing between isolates, strains and species of wood decay basidiomycetes, and identifying new isolates.
A Vigrow, D Button, J W Palfreyman, B King, B M Hegarty


The effect of didecyldimethylammonium chloride on growth of different strains of mould fungus Gliocladium roseum
1995 - IRG/WP 95-10105
The tolerance and degrading ability of different strains of Gliocladium roseum towards didecyldimethylammonium chloride (DDAC) were studied. All four of the strains of Gliocladium roseum were tolerant to DDAC and after their growth on amended malt agar, the retention of DDAC in the medium was reduced.
Yu Zheng, J N R Ruddick


The effect of temperature on the rate of fixation of an alkyl ammonium compound (AAC) wood preservative
1984 - IRG/WP 3293
The rate of fixation of an alkyl ammonium compound wood preservative was measured by soaking samples of wood wool in various preparations of the preservative for arbitrary times followed by immediate leaching in water. The wood wool was then analysed for residual preservative. The results indicated that fixation was very rapid and increased at higher temperatures.
P Vinden


Monographic information on Serpula (Poria) incrassata according to the "Model Questionnaire for preparation of monographic cards for wood-destroying fungi"
1980 - IRG/WP 160
J G Palmer, W E Eslyn


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