Your search resulted in 42 documents. Displaying 25 entries per page.
Alternative technologies for wood wastes recycling - Part B: Biotreatment of PCP- and creosote-treated wood
1998 - IRG/WP 98-50101-18 b
Alternative technologies have been investigated to detoxify treated wood. Two classes of organic compounds are studied. Creosote-treated wood are classified in France as dangerous wood wastes. A conventional incineration could be provided for these wood wastes but the cost of this elimination could be very high (> 2000 FFR/ton). For these reasons, we have tested two kinds of new processes as alternative ways. The developed strategy is described in this paper and illustrated by a few examples. Part B - The second one is based on an oxidative degradation of organic compounds directly in the wood: oxidative degradation by fungi. Few examples are presented in this paper. Three fungi are tested directly on treated wood. High levels of contaminants are tested around 0.6 g of PCP/kg and 3.7 g of 8 PAH/kg of wood. Few oxidation products generated by this biological treatment are identified. An ecotoxicological assessment is performed to validate this process. Technical feasibility of these developed processes as well as economic aspects are discussed,
S Legay, P Marchal, G Labat
Alternative technologies for wood wastes recycling - Part A: Supercritical extraction of PAH compounds from wood wastes
1998 - IRG/WP 98-50101-18 a
Alternative technologies have been investigated to detoxify treated wood. Two classes of organic compounds are studied. Creosote-treated wood are classified in France as dangerous wood wastes. A conventional incineration could be provided for these wood wastes but the cost of this elimination could be very high (> 2000 FFR/ton). For these reasons, we have tested two kinds of new processes as alternative ways. The developed strategy is described in this paper and illustrated by a few examples. Part A - The first one is based on the use of supercritical fluid as C02 to solubilize organic compounds as organochlorine compounds and Polycyclic Aromatic Hydrocarbons (creosote) from treated wood. Kinetics results of this extractive process are presented on the basis of 200 g of wood.
L Schrive, C Perre, G Labat
Borates and their biological applications
1998 - IRG/WP 98-30178
This paper reviews some of the many biological applications of borates. Boron is a ubiquitous element found widely distributed in the environment and is a normal component of a healthy diet. Elemental boron does not exist in nature, but is always found combined with oxygen in compounds called borates. Boron is an essential micronutrient for plants, and there is evidence to suggest that boron is of nutritional importance, if not essential, for humans. Borates possess biostatic activity which enabled their use in medicine and has allowed their continued development as preservatives. The essentiality of boron in plants has led to extensive biological use in agriculture. The biostatic properties at high doses have enabled their use in biodeterioration control, against insects, fungi, algae and bacteria. Some use is currently being made of borates for insect control in the home. The application of borates to crops, to alleviate boron deficiency, has resulted in recognized increases in quality and yield. Consideration of the relative safety and effectiveness of borates as biocides, is expected to lead to an increase in the use of these products in the future.
J D Lloyd
Chemical analysis for TBTN in LOSP-treated wood and preservative fluids
1994 - IRG/WP 94-20027
Tributyltin napthenate (TBTN) is being substituted for tributyltin oxide (TBTO) in LOSP preservative formulations because its lower reactivity/better stability allows co-formulation with synthetic pyrethroids. Better stability may reduce molecular degradation both in-service and during analysis. It was considered necessary to check whether TBTO analysis methods were suitable for use on TBTN treated wood. Five analytical methods for TBTO in wood were applied to TBTN-treated pine sapwood, and evaluated for recovery, accuracy and precision. It was found that treated wood could be oven-dried before analysis, eliminating the need to run parallel moisture content determinations. The best performing method involved extraction of TBTN from oven-dry treated wood with acidified ethanol followed by AAS determination of tin. Performance was checked on freshly-treated and aged material.
D P Wraight, M J Kennedy
1983 - IRG/WP 3268
Rapid analytical methods for wood waste - An overview
1998 - IRG/WP 98-50104
The proper handling of wood after service is a today's problem. Untreated wood could be reused or may be used as fuel. For treated wood special care is demanded to avoid environmental impacts. Thus, analytical methods are requested to detect rapidly whether and to what extend wood is contaminated, covering a wide spectrum of organic and inorganic agents used during the last 50 years. Traditional methods can not meet today's requirements due to their time consumption or high detection limits. Modern analytical techniques are widely used in research and industry, but their application for wood waste is still difficult due to the complex and differing organic structure of wood. An overview on analytical methods, their chances and limits will be given. In particular it is reported on a joint research programme initiated by the German Environment Foundation. The program aims at the development of a single or combined method that is able to detect both, organic and inorganic contaminations in wood in industrial scale. This technique shall be suitable for the entrance control at waste disposal sites as well as the controlled demolition. The most promising techniques for fast analises are based on Laser-Plasma-Atomic-Emmission-Spectroscopy for inorganic agents and Ion-Mobility-Spectroscopy for organic agents.
A Peylo, R-D Peek
Soil chemistry and wood decay
1978 - IRG/WP 2109
Soil is a most complex biological, chemical and physical material; its study is effectively a separate branch of science but almost entirely in relation to ist ability to grow plants - this paper is intendet just to note some known facets that might have relevance to the decay of wood and the performance of wood preservatives.
E A Hilditch
Accelerated laboratory soil contact decay test using soil amended with composted wood
2004 - IRG/WP 04-20284
The effect of amending soil with wood compost on the decay rate of wood wafers in contact with the unsterile soil, as measured by radial compression strength loss, was explored. It was found that the addition of composted wood to the soil significantly increased the wood decay rate. The reason for this acceleration in wood decay is not entirely clear, but appears to be at least partially associated with the fungal inoculum provided by the wood compost. These results indicate that this method may be useful in the development of accelerated soil contact decay tests.
D D Nicholas, H Borazjani, T Schultz
Copper naphthenate: An analysis of the materials found in the worldwide marketplace using a new analytical technique
2000 - IRG/WP 00-30224
Naphthenic acid has been recovered from products of petroleum refining for well over 100 years. The metal soaps, specifically copper and zinc naphthenate, have been evaluated and used as commercial wood preservatives for in excess of 60 years. Most of the early data supporting the continued use of copper naphthenate as a wood preservative was based on materials manufactured from naturally occurring naphthenic acid derived from petroleum. Recent work investigating pesticide label claims for materials asserting to be naphthenic acid salts of copper has in fact shown the presence of many synthetic carboxylic acids as substitutes for naphthenic acid. Additionally, some earlier efficacy studies indicated that non-naphthenate salts of copper actually seemed to promote decay in laboratory tests. This work investigates several sources of copper naphthenate in commercial markets and investigates a novel analytical technique and a modification of this technique to characterize the copper naphthenates found in commercial use worldwide. The basic analytical technique was recently published as an appendix to the American Wood Preservers' Association P-5 (Methods for Chemical Analysis) Sub-Committee annual report to assure compliance with the AWPA P8 Standard.
J A Brient, R E Moyer, M H Freeman, H Jiang
Natural weathering of wood in a sunny climate effects on surface chemistry and paint adhesion
1997 - IRG/WP 97-20109
Radiata pine veneers and blocks were exposed to natural weathering under Australian summer conditions over a period of 30 days. Infrared spectroscopy revealed that there was perceptible surface delignification after 4 hours exposure, substantial surface delignification after 3 days exposure and almost complete surface delignification after 6 days. Viscometry determinations on holocellulose samples from weathered veneers and unweathered controls indicated significant depolymerisation of cellulose after short periods of weathering. A tape test was used to assess the adhesion of acrylic latex primers to weathered blocks. The adhesion of exterior acrylic primers decreased on weathered wood surfaces and was significantly lower on specimens that were weathered for 5 to 10 days. An oil-modified acrylic primer showed greater adhesion to weathered wood surfaces. Primer adhesion was lower on weathered radial surfaces than on similarly exposed tangential surfaces. The practical implications of these findings for the coating of exterior wood with acrylic latex primers and the development of photoprotective treatments for wood are discussed briefly.
P D Evans, P D Thay, K J Schmalzl
Development of a turbidity method for the determination of water repellent in CCA treatment solutions
2000 - IRG/WP 00-40177
The use of aqueous water repellent emulsion formulations has increased significantly in the wood treatment industry. These are primarily used to enhance the weathering characteristics of wood products treated with water borne preservatives systems used in exterior above ground exposures. However, they are also used in pole treatments to improve the climbing characteristics and in low VOC millwork treatments. With the increase in water repellent treated wood production there was a requirement to develop analytical methods for the determination of the water repellent concentration in treatment solutions for quality control at wood treatment facilities. Various methods were examined for the determination of water repellent emulsions in wood treatment solutions. Of the methods considered the turbidity method was found the best suited for routine quality control at treated wood production facilities. The effects of emulsion concentration and particle size on the turbidity measurements were evaluated.
P J Walcheski, L Jin
The environmental chemistry of chromium: Science vs. U.S. law
1993 - IRG/WP 93-50014
The cooperation which existed among chromium chemical producers, industrial health laboratories, and governmet agencies was destroyed after 1970 by the advent of environmental activism and regulatory legislation. As prewar plants had been found to pose a serious cancer risk, this fact was the basis of EPA regulations, especially during the term of Joe Califano in HEW under Jimmy Carter. However, as health problems were identified by industry, the legal implications soon became apparent, and corporate scientists could release information only after clearance. This destroyed the free exchange of information necessary to the solution of scientific problems. Within the past few years, the closure of allied plants, the resolution of some superfund litigation, plus the release of records to the historical files at the Chemical Heritage Foundation, has clarified the scientific record. The following will be discussed: (1) The tendency of the present legal system to exaggerate risk. (2) Actual risks involved from inhalation, skin contact, and effluents. (3) the application of these principles to production, use and disposal of CCA and CCA-treated wood.
W H Hartford
Analysis of water repellents in wood treated with water borne formulations using FTIR
2000 - IRG/WP 00-40176
The use of aqueous water repellent emulsion formulations has increased significantly in the wood treatment industry. These products are primarily used to enhance the weathering characteristics of wood products treated with water borne preservatives systems used in exterior above ground applications. They are also used in pole treatments to improve climbing characteristics and in low VOC millwork treatments. With the increasing usage of such products. there has been a need to develop analytical methods for the determination of the water repellent in treated wood products to ensure product quality and to aid in the development of enhanced water repellent formulations. A method for the determination of the water repellent concentration in wood was developed using Fourier transform infrared spectroscopy (FTIR). The wood samples were extracted and prepared for the FTIR scans using a liquid cell. The water repellent concentration was determined by using the intensity of the hydrocarbon C-H stretch adsorption. Methods for correcting or eliminating the interference from non-water repellent components in the wood extracts were developed.
P J Walcheski, L Jin
Silafluofen: Novel chemistry and versatility for termite control
1995 - IRG/WP 95-30069
A novel silicon - containing insectizide, HOE 084498 ('Silafluofen'), with a favourable toxicological profile, has shown activity against a broad spectrum of agricultural and environmental health pests. Results from laboratory and field studies around the world have demonstrated that silafluofen is effective at protecting timber from attack by various species of termite and wood-boring beetle. As a termiticide, silafluofen, applied as a dust-toxicant, may suppress/eliminate Coptotermes sp. Ongoing field trials in France, in cooperation with CTBA, indicate that silafluofen, injected directly into masonry, has controlled Reticulitermes santonensis. No signs of termite activity have been observed in the treated part of an infested house since the application was made, 2 years ago.
A J Adams, A Jermannaud, M-M Serment
Natural Durability studies and Changes in wood chemistry of some Ghanaian hardwoods during decay by white- and brown-rot fungi
2004 - IRG/WP 04-10542
The natural decay resistance of Esa (Celtis mildbraedii), Wawabima (Sterculia rhinopetela) and Dahoma (Piptadeniastrum africanum) obtained from Ghana was determined according to BS EN 113 (1997). Esa was found not durable to the white-rot, but very durable to the brown-rot; Wawabima was very durable to both white- and brown-rots; and Dahoma was durable to the white-rot, and very durable to the brown-rot. The natural durability ratings for the timbers in accordance with BS EN 350-1 (1994) are: Esa 5, Wawabima 1, and Dahoma 2. Changes in chemical composition of Esa (which has the lowest durability), when exposed to the different decay fungi at various stages of decay, were studied using HPLC, FT-IR and gravimetric methods. Results of the gravimetric and FT-IR analysis suggested that, generally, the white-rot fungi (Trametes versicolor and Phanerochaete chrysosporium) degraded the cellulose, hemicelluloses and lignin simultaneously. The brown-rot fungus (Coniophora puteana) however, degraded the cellulose and hemicellulose and left the lignin virtually untouched. The HPLC results revealed that Trametes versicolor and Phanerochaete chrysosporium degraded the cellulose component (glucose) and the main hemicellulose component (xylose and mannose) at similar rates. However, the brown-rot fungus, Coniophora puteana degraded mannose faster than glucose and xylose. Changes in the components of the branch chains of the hemicelluloses were found to be different according to the various fungi. However, in all cases, rhamnose was consumed faster than the other components, arabinose, galactose and 4-O-methyl-glucuronic acid, at the early stages of decay.
Zeen Huang, K Maher, S A Amartey
Optimisation of an analytical method for the determination of total fluoride in preservative-contaminated soils using water steam distillation and an ion-selective electrode
1999 - IRG/WP 99-20153
This paper describes a simple modified procedure for the quantitative fluoride determination of different origin in a soil matrix using a water steam distillation and an ion-selective electrode. Distillation methods generally require a preliminary preparation step like fusing. The modified method presented here is based on the direct distillation of fluoride so that no further sample preparation is necessary. The separation is carried out in a perchloric acid medium and the analysis takes place by means of a reduced Total Ionic Adjustment Buffer (TISAB) solution. This technique allows also the application of a battery equipment, i. e. simultaneous distillation will be possible. Using a 2-flask system approximately 10 soil samples with two parallels can be analysed per day. The adaptation of the test method, possible checked parameters of influence, the obtained results and observed problems are discussed. The results showed that in general satisfying (>90%) recovery rates can be received.
On the nature of the tertiary wall in wood cells. Summary of lecture given at 9th Annual Meeting, Noordwijk-aan-Zee, Holland
1977 - IRG/WP 169
During recent discussions on the possible causes of failure of treated hardwood species by soft rot fungi, the uneven micro distribution of toxic components was found to be of importance; this might be attributed to a restricted diffusion of the preservative from the cell lumina into the cell wall.·In this context, the nature of the tertiary wall as the inner lining of wood cells merits special attention. In the following, the present knowledge concerning the wall layer is summarized.
A comparison of analytical techniques
1995 - IRG/WP 95-20061
This paper compares carefully-controlled weight retentions and analysis by XRF, ICP, combustion methods and a new extraction procedure for the new preservative, Copper(II) Dimethyldithiocarbamate (CDDC). Various experimental parameters such as particle size and drying conditions were investigated. In general, the correlations between and among the procedures are very high. The extraction-colorimetric procedure developed for assay of CDDC was verified by comparison to AWPA Standard analytical techniques.
A C Gallacher, C R McIntyre, M H Freeman, D K Stokes, W B Smith
Wood preservation requirements in Queensland, Australia
1983 - IRG/WP 3227
In Queensland the preservative treatment and utilization of timber must comply with the Timber Users' Protection Act. Preservative retention levels and penetration patterns must be complied with. Analytical zones are specified for removing samples for chemical analysis of preservative retention. The required retention levels have been expressed as percent weight of oven dry wood weight. This specification has allowed the same retention figures to be equally effective in preserving timber species of differing densities.
L E Leightley, M J Kennedy
The role of toilet paper in studies of desert subterranean termites in Arizona, USA
2000 - IRG/WP 00-10375
Toilet paper rolls were used as a substrate for observing foraging activity of Heterotermes aureus (Snyder) and Gnathamitermes perplexus (Banks) in the Sonoran Desert of Arizona. Foraging was minimal during the winter months, increased in the spring, was high but erratic in the summer, and then was moderate again in the fall. H. aureus foraged within a temperature range of 7.6° to 47°C, G. perplexus foraged within a range of 9° to 49°C. Temperature had the greatest influence on the number of foragers appearing at the soil surface. Rainfall (and resulting soil moisture) greatly affected foraging in the summer. Density of H. aureus foragers was estimated to be 4.31 x 106, while the density of G. perplexus was about twice that of H. aureus. Density of H. aureus colonies was ca. 190.4 colonies/hectare with an average of 22,632 foragers/colony and an average foraging territory of 12.5m2. Together, these two species transported soil to the soil surface at a combined rate of 744.2kg/hectare/year. Both species brought up soil richer in clay and added significant quantities of organic carbon, nitrogen, PO4, Na, Mg, and soluable salts, while H. aureus alone increased soil K.
M I Haverty
A comparison of analytical and visual techniques used for assessment of weathering properties of chromium and copper azole treated timber
1994 - IRG/WP 94-20023
The weathering properties of preservative treated timber were studied by measuring surface lignin loss and by microscopic examination after weathering, and results were related to qualitative assessments of visual appearance after weathering. Measurement of relative rates of delignification of untreated and preservative treated timber obtained by FTIR analysis, and weight loss determined on thin veneers, correlates well with visual assessments of comparative rates of weathering on solid timber exposed to natural weathering in service. Copper Azole treated timber and timber treated with chromium based preservatives showed good resistance to weathering.
J A Cornfield, M D C Hale, G Fettis
Diagnostics methods and routes proposalsto define selective sorting of demolition wood wastes
2001 - IRG/WP 01-50177
Wood wastes are more and more often used in different wood waste valorisation industries (panels, wood energy, cement factories, ...). These industries are in progress to include in their processes, wood wastes coming from demolition wood. A state of the art and an analysis have been made to propose : (1) diagnostics methods to carry out a classification of wood wastes on demolition sites and in the sorting sites based on analytical methods, (2) routes to carry out the classification of wood wastes (according to products present in wood wastes : biocides, finishing products, and according to French regulation requirements). Some proposals are discussed.
G Labat, E Bucket, C Fréret, G Deroubaix
Effect of soil chemistry and physical properties on wood preservative leaching
1998 - IRG/WP 98-50111
When treated wood is placed in contact with soil, complicated mass transfer and chemical reactions occur which causes the preservative components to leach from the wood. There are several factors that are known to affect the amount of chemical leached from wood. These are properties of the preservative and carrier, preservative retention, degree of fixation, exposure time, grain orientation, surface area of the product, wood species, and site factors. With regard to site factors, the chemical and physical properties of soil play an important role in the depletion of biocides from treated wood. The effect of soil properties on the leaching of wood preservatives has only been studied to a limited degree but appears to be a major factor in the performance of treated wood. In this study the effect of five soils with widely different physical and chemical properties on the leaching of chromated copper arsenate (CCA-C), pentachlorophenol (Penta) and didecyldimethylammonium chloride (DDAC) from southern pine was evaluated.
Joan-Hao Wang, D D Nicholas, L S Sites, D E Pettry
Water analysis in chemicals, wood or chemically treated wood using a new analytical method for selective water detection
2006 - IRG/WP 03-30391
Water or moisture content analysis can be a challenging task in many applications. However, knowing accurately the type of water which can be found in a given sample or product can provide important information about a chemical compound used for wood treatment and especially about the treated wood sample. Moisture content in wood plays an important role in fungal growth and it needs to be extensively monitored. In this study, a new method for the moisture content or trace water analysis will be reviewed. The principle of the method, the main components of the device, the advantages and disadvantages of the method called Selective Water Detection System (SWDE), will be reviewed and presented. Probe molecules and wood samples will be used to explain and examine the type of information one can get using this analytical method. The method can provide information about how water is bonded to a substrate and what type of interactions water has in a sample. This information can be used to evaluate the structure of a chemical used in wood preservation, monitor the water repellency, or determine the type of chemical compound present on the treated wood (e.g. hydration number, weakly or strongly bonded water molecules, etc.). Probe molecules based on boron, commonly used as wood preservative will be used to explain and describe the instrument capabilities and the type of scientific information which can be obtained.
R Craciun, D Taylor
Chelator-Mediated Fenton Chemistry in Wood Degraded by Fungi
2007 - IRG/WP 07-10618
Wood specimens were colonized by individual isolates of brown rot, white rot, soft rot and blue (sap) stain fungi. Ethyl acetate extracts of the ground wood were analyzed for their iron-reducing capabilities using a ferrozine-based assay. Extracts from wood colonized by brown rot fungi showed a significantly greater iron-reducing capability than extracts from wood colonized by white rot fungi or non-decay fungi. The ability of brown rot fungi to produce compounds, and/or modify the wood components, that reduce iron is of relevance to the “chelator-mediated Fenton mechanism” that has been advanced as a theory in the non-enzymatic degradation of wood by the brown rot fungi.
B Goodell, G Daniel, J Jellison, Yuhui Qian