CCA-treated Wood Research Articles

Characteristics of chromated copper arsenate-treated wood ash

The combustion of recovered wood from construction and demolition waste as biomass fuel is a common practice. When chromated copper arsenate (CCA)-treated wood is present as part of the wood fuel mix, concentrations of arsenic, chromium, and copper become elevated in the ash. The objectives of this study were to estimate the fraction of CCA-treated wood needed to cause the ash to fail regulatory guidelines and to test a series of solvents for the purpose of extracting the metals from the ash. Ash samples were prepared in an industrial furnace using samples of CCA-treated wood, mixtures of CCA-treated wood and untreated wood, and recycled wood waste collected at construction and demolition recycling facilities. Regulatory guidelines were evaluated by measuring total metals concentrations (using neutron activation analysis) and by conducting standardized leaching tests (toxicity characteristic leaching procedure (TCLP) and synthetic precipitation leaching procedure (SPLP)) on the ash. Ten different solvents, ranging from distilled water to strong acids, were also tested for their ability to extract metals. Results of this study indicate that metal concentrations (chromium plus copper plus arsenic) can be as high as 36% of the ash by weight for treated wood samples containing high retention levels (40 kg/m 3) of CCA. All ash samples from the combustion of 100% CCA-treated wood and mixtures containing 5% CCA-treated wood leached enough arsenic (and sometimes chromium) to be characterized as a hazardous waste under US regulations. Concentrated nitric acid, which was the most effective solvent tested, was capable of removing between 70 and 100% of the copper, between 20 and 60% of the chromium, and 60 and 100% of the arsenic for samples characterized by low retention levels. A particular finding of interest was the efficiency of distilled water and other weak solvents to extract measurable amounts of chromium, especially for ash samples containing low retention levels of CCA. Citric acid was particularly effective at removing arsenic (between 40 and 100%) for ash samples produced from wood containing low CCA retention levels.

Special Treatment: Disposing of CCA-Treated Wood

Research ArticleOpen AccessSpecial treatment: disposing of CCA-treated wood. W C Holton W C Holton Search for more papers by this author Published:1 June 2001https://doi.org/10.1289/ehp.109-a274Cited by:3AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit FiguresReferencesRelatedDetailsCited by Fukuyama T, Ueda H, Hayashi K, Tajima Y, Shuto Y, Kosaka T and Harada T (2008) Sensitizing Potential of Chromated Copper Arsenate in Local Lymph Node Assays Differs with the Solvent Used, Journal of Immunotoxicology, 10.1080/15476910802085715, 5:2, (99-106), Online publication date: 1-Jan-2008. Solo-Gabriele H, Townsend T, Hahn D, Moskal T, Hosein N, Jambeck J and Jacobi G (2004) Evaluation of XRF and LIBS technologies for on-line sorting of CCA-treated wood waste, Waste Management, 10.1016/j.wasman.2003.09.006, 24:4, (413-424), Online publication date: 1-Jan-2004. Moskal T and Hahn D (2016) On-Line Sorting of Wood Treated with Chromated Copper Arsenate Using Laser-Induced Breakdown Spectroscopy, Applied Spectroscopy, 10.1366/000370202760355316, 56:10, (1337-1344), Online publication date: 1-Oct-2002. Vol. 109, No. 6 June 2001Metrics About Article Metrics Publication History Originally published1 June 2001Published in print1 June 2001 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

Special treatment: disposing of CCA-treated wood.

Research ArticleOpen AccessSpecial treatment: disposing of CCA-treated wood. W C Holton W C Holton Search for more papers by this author Published:1 June 2001https://doi.org/10.1289/ehp.109-a274Cited by:3AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit FiguresReferencesRelatedDetailsCited by Fukuyama T, Ueda H, Hayashi K, Tajima Y, Shuto Y, Kosaka T and Harada T (2008) Sensitizing Potential of Chromated Copper Arsenate in Local Lymph Node Assays Differs with the Solvent Used, Journal of Immunotoxicology, 10.1080/15476910802085715, 5:2, (99-106), Online publication date: 1-Jan-2008. Solo-Gabriele H, Townsend T, Hahn D, Moskal T, Hosein N, Jambeck J and Jacobi G (2004) Evaluation of XRF and LIBS technologies for on-line sorting of CCA-treated wood waste, Waste Management, 10.1016/j.wasman.2003.09.006, 24:4, (413-424), Online publication date: 1-Jan-2004. Moskal T and Hahn D (2016) On-Line Sorting of Wood Treated with Chromated Copper Arsenate Using Laser-Induced Breakdown Spectroscopy, Applied Spectroscopy, 10.1366/000370202760355316, 56:10, (1337-1344), Online publication date: 1-Oct-2002. Vol. 109, No. 6 June 2001Metrics About Article Metrics Publication History Originally published1 June 2001Published in print1 June 2001 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

WRESTLING WITH THE PLAGUES OF WOOD

A S CONCERNS ABOUT THE SAFETY of chemically treated wood increase, researchers are seeking alternative ways to preserve wood. About 80% of wood used in the U.S. is treated with chromated copper arsenate (CCA). This mixture of the oxides of chromium, copper, and arsenic imparts a familiar green color to wood, which is obvious in newly installed decks or telephone poles. The American Council on Science & Health, a consumer education consortium, says CCA-treated wood poses no known health hazard. Studies by the Environmental Protection Agency have concluded that the CCA-treated wood does not pose unreasonable risks. But recent developments have placed CCA-treated wood under siege. Last month, for example, a lawsuit filed in U.S. District Court in Miami against producers and distributors of CCA-treated wood claims the product is unsafe and seeks, among other demands, medical monitoring of people who come in contact with it. The complaint cites a study by the University of ...

Leachability and decay resistance of particleboard made from acid extracted and bioremediated CCA-treated wood

Composite manufacturing appears to be one of the most suitable recycling options for chromated copper arsenate (CCA)-treated waste wood. However, in many applications it would be beneficial to remove much or all of the CCA from the wood prior to composite production. This paper evaluates the effect of remediation processes, namely oxalic acid (OA) extraction and Bacillus licheniformis fermentation, on leaching of copper, chromium, and arsenic from particleboard made from remediated wood particles and also investigates decay resistance of the particleboard. Oxalic acid extraction and bioremediation by B. licheniformis affected the chemical properties of wood particles and significantly increased leaching of elements from CCA-treated wood particles. The particleboard containing OA-extracted and bioremediated particles showed generally high leaching losses of remaining elements. Exposure of particleboards to decay fungi in soil block tests indicated that boards containing CCA-treated particles were most resistant to fungal degradation. Also, for a given board type, Gloeophyllum trabeum resulted in greater weight losses than Postia placenta and Trametes versicolor after 12-week exposure. We concluded that bioremediation of CCA-treated wood is a promising method of safely reusing treated fiber, although chemical extraction diminished the properties of composites prepared from this material.

Study of Extraction of Metals from CCA-Treated Wood with Supercritical CO2Containing Acetylacetone: Extraction of Cu by Continuous Addition of Acetylacetone

Although waste CCA-treated wood containing toxic heavy metals (Cu, Cr, and As) can contaminate soil and be hazardous to human health, there is currently no reliable detoxification technique. To solve this problem requires a method for extracting the toxic metals from such wood. We have previously shown that supercritical CO2 with initially added acetylacetone (AA) as a chelating agent achieved a Cu extraction ratio of up to 71.0%. The purpose of this study was to explore conditions for improving the extraction efficiency of Cu: that is, to extract Cu by using supercritical CO2 with continuously added AA and to investigate the effect of the flow rate and AA/CO2 mixing ratio on the extraction behavior. The highest ratio we obtained for Cu was 89.4% at 14.7 MPa and 423.2 K with a flow rate of 0.40 mol/min and a mixing ratio of 4.8 mL of AA/mol of CO2. We found that the extraction process consisted of static and dynamic extraction stages and that a high flow rate produced a high extraction rate. After the extraction had proceeded for a while, the extraction rate decreased because of the decrease in the residual metal in the wood.

00/03489 Total recycling of CCA-treated wood waste by low-temperature pyrolysis

00/03489 Total recycling of CCA-treated wood waste by low-temperature pyrolysis

Copper Accumulation in the Digestive Caecae of Limnoria quadripunctata Holthius (Isopoda: Crustacea) Tunnelling CCA-Treated Wood in Laboratory Cultures

Summary To investigate the mechanisms by which the isopod Limnoria tolerates copper, chromium and arsenic when tunnelling CCA-treated wood in the marine environment, digestive caecae of specimens of L. quadripunctata from CCA-treated and untreated Pinus sylvestris sapwood were examined using transmission electron microscopy (TEM) and energy dispersive X-ray detection (EDX). Copper-containing granules were found to be present in the small cells of the digestive caecae (midgut) of Limnoria from both treated and untreated wood. However, individuals tunnelling treated timber contained a greater number of granules, with six types of morphology being distinguished of which only two were present in Limnoria from untreated wood. The presence of copper-containing granules in Limnoria from untreated timber may be explained by the ability of this isopod to acquire and store copper from seawater for use in enzymes and blood pigments. The increased number of copper granules in individuals tunnelling treated wood was believed to result from elevated levels of this element in the food substrate. This ability to store copper allows these organisms to tolerate this metal in the wood substrate and may explain how this organism is able to attack CCA-treated wood in service. No chromium, or arsenic, was detected in the digestive caecal cells.

CCA removal from treated wood using a dual remediation process

Novel approaches to remediate chromated-copper-arsenate (CCA)-treated waste wood are needed to divert this material from landfills. In this study, CCA-treated wood wafers were treated with a two-step remediation process to remove copper, chromium and arsenic. Process conditions, involving an acid extraction and bacterial culture with a metal-tolerant bacterium, were optimized. It was determined that 18 h of exposure to 1.0% oxalic acid was an optimal exposure time for the size of wood used in this study. Oxalic acid concentration was then varied to determine optimal concentration for metal removal. Increasing concentrations of oxalic acid removed increasing quantities of copper, chromium and arsenic. Acid extraction at 0.80% and bacterium exposure resulted in a total reduction of 78% copper, 97% chromium and 93% arsenic. An 0.8% of oxalic acid followed by bacterial culture with Bacillus licheniformis CC01 afforded the best conditions for maximum removal of copper, chromium, and arsenic from treated wood w...

CCA removal from treated wood using a dual remediation process

Novel approaches to remediate chromated-copper-arsenate (CCA)-treated waste wood are needed to divert this material from landfills. In this study, CCA-treated wood wafers were treated with a two-step remediation process to remove copper, chromium and arsenic. Process conditions, involving an acid extraction and bacterial culture with a metal-tolerant bacterium, were optimized. It was determined that 18 h of exposure to 1.0% oxalic acid was an optimal exposure time for the size of wood used in this study. Oxalic acid concentration was then varied to determine optimal concentration for metal removal. Increasing concentrations of oxalic acid removed increasing quantities of copper, chromium and arsenic. Acid extraction at 0.80% and bacterium exposure resulted in a total reduction of 78% copper, 97% chromium and 93% arsenic. An 0.8% of oxalic acid followed by bacterial culture with Bacillus licheniformis CC01 afforded the best conditions for maximum removal of copper, chromium, and arsenic from treated wood with minimal exposure of the wood fiber to acid conditions.

Chromated Copper Arsenate-Treated Wood in Recovered Wood

Wood represents approximately 25% of the C&D waste stream, and a possible limitation to wood recycling is the presence of CCA-treated wood. Research was performed to measure the percentage of chromated copper arsenate (CCA)-treated wood present in recovered wood stockpiles at construction and demolition (C&D) waste recycling facilities in Florida. Because of the elevated levels of chromium, copper, and arsenic in CCA-treated wood the presence of this material in C&D-recovered wood waste limits possible management options. Quantifying the fraction of C&D wood waste comprised of CCA-treated wood is a necessary first step in addressing this issue. Shredded wood samples were collected from the 12 C&D recycling facilities in Florida in an effort to quantify the fraction of recovered wood that was treated with the waterborne preservative CCA. The samples were further size reduced and mixed, and ultimately ashed at 550°C in a laboratory furnace. Copper and chromium concentrations in the ash were measured using a flame atomic absorption spectrophotometer. These concentrations were used to calculate the amount of CCA-treated wood present in the original wood samples. The average percentage of 0.25-pcf standard retention, Type C, CCA-treated wood was estimated to be 6.5% based on copper and 5.9% based on chromium. In addition to providing needed measurements of CCA wood presence in C&D-recovered wood, this paper presents a methodology for estimating CCA wood amounts at other locations. Key words: Construction and demolition waste; CCA; chromium; copper; waste wood; recycling; treated wood; wood; solid waste

Disposal practices and management alternatives for CCA-treated wood waste

Limited information is available about the ultimate fate of chromated copper arsenate (CCA)-treated wood waste upon disposal. This lack of information, coupled with concerns over potential environmental impacts, has prompted the current investigation, which focuses on establishing an inventory for this waste stream and identifying alternatives to current disposal practices. The state of Florida (USA) was utilized as a case study for this investigation. The results indicate that approximately 300 metric tonnes of the chemical were disposed of in Florida during 1996. By the year 2006 this figure will quadruple and by 2016 it will reach a value of 2700 metric tonnes. The majority of CCA-treated wood waste is processed through construction and demolition recycling facilities, resulting in a wood waste composition containing on average 6% CCA-treated wood. The primary market for wood waste in Florida is energy recovery and, as a consequence, the majority of CCA-treated wood waste is inadvertently burned for energy recovery purposes. Recommendations for handling this waste stream are discussed. Recommendations include options for waste minimization, reuse, recycling, and ultimate disposal.

Disposal practices and management alternatives for CCA-treated wood waste

Limited information is available about the ultimate fate of chromated copper arsenate (CCA)-treated wood waste upon disposal. This lack of information, coupled with concerns over potential environmental impacts, has prompted the current investigation, which focuses on establishing an inventory for this waste stream and identifying alternatives to current disposal practices. The state of Florida (USA) was utilized as a case study for this investigation. The results indicate that approximately 300 metric tonnes of the chemical were disposed of in Florida during 1996. By the year 2006 this figure will quadruple and by 2016 it will reach a value of 2700 metric tonnes. The majority of CCA-treated wood waste is processed through construction and demolition recycling facilities, resulting in a wood waste composition containing on average 6% CCA-treated wood. The primary market for wood waste in Florida is energy recovery and, as a consequence, the majority of CCA-treated wood waste is inadvertently burned for energy recovery purposes. Recommendations for handling this waste stream are discussed. Recommendations include options for waste minimization, reuse, recycling, and ultimate disposal.

Low-temperature pyrolysis of CCA-treated wood: thermogravimetric analysis

A thermo-analytical study of untreated and chromated copper arsenate (CCA) treated wood samples is performed in order to obtain a better understanding of the low-temperature pyrolysis of CCA-treated wood waste in an inert atmosphere. The type of wood used in this study is Pinus sylvestris sapwood. The influence of the presence of CCA and the heating rate on the pyrolytic behaviour of wood samples is studied, as well as the release of volatile compounds and metals (Cr, Cu, As) during the pyrolysis process. This paper shows that CCA has a significant influence on the thermal behaviour of wood samples, which is more pronounced the higher the CCA concentration of the sample is. The temperature at the onset of pyrolysis, as well as the temperature where the maximum rate of decomposition occurs, are lowered by the CCA treatment. The final char yield (including the metals) is higher and the rate of weight loss is much more peaked for CCA-treated wood. It could be postulated that the CCA compounds act as promotors of the pyrolysis reactions favouring the formation of char. For higher heating rates, there is a shift of the DTG peak to higher temperatures for both untreated and CCA-treated wood samples. Within the accuracy of the evolved gas analysis (EGA) method applied, it is observed that the presence of CCA does not significantly influence the type and relative amount of measured volatiles. The volatilisation of metal compounds is shown to be strongly dependent on temperature and residence time of the wood sample at a given temperature. A critical point (10 min at 400°C) exists, below which the release of Cr and Cu is negligible and the release of As is below 10%. Above this critical point (longer times at 400°C), there is a dramatic increase in metal release for all three metals. The CCA concentration itself also has an influence in the sense that higher concentrations in the original sample give higher relative concentrations of metals in the resulting pyrolysis residue.

Accumulation of metals in consumers associated with chromated copper arsenate-treated wood panels

Metals leached from chromated copper arsenate (CCA)-treated wood, taken up by epibiota and trophically transferred to their motile consumers or taken up directly by the consumers, were measured in caged organisms exposed to treated and untreated wood panels for 3 months. Epibiota on treated panels had more copper and arsenic than epibiota on untreated panels, and amphipods living on the former had elevated copper. However, metal concentrations in grass shrimp ( Palaemonetes pugio) and two teleost fish, the naked goby ( Gobiosoma bosci) and mummichog ( Fundulus heteroclitus), were unaffected by CCA-treated wood exposure. In addition, there was no evidence of biomagnification in the consumers other than the amphipods. Thus, trophic transfer was not demonstrated to the consumers, suggesting that the treated wood was not presenting a hazard to higher trophic levels. Fish may have more efficient mechanisms for regulating metal levels in their tissues. ©

Prevention of Colony Foundation by Cryptotermes brevis and Remedial Control of Drywood Termites (Isoptera: Kalotermitidae) with Selected Chemical Treatments

A wooden trap-block bioassay, tested over 2 flight seasons, was found to be a suitable colonization platform for Cryptotermes brevis (Walker) dealates. A crevice designed into trap blocks Was the preferred locus for nuptial chamber construction by dealates. Lone heterosexual pairs were found in 52%of chambers containing live termites. Of colonies containing brood, 80%were headed by lone heterosexual pairs. The broods in 4- or 6-mo-old C. brevis colonies were small, with ≤3 eggs, larvae, or a combination. In 1995, a choice test of disodium octaborate tetrahydrate (DOT) solution, chromium copper arsenate (CCA), and water-treated (control) trap blocks was exposed to swarming C. brevis . Four months after swarming ceased, live dealates and brood were recovered from nuptial chambers in control blocks, but not from DOT or CCA-treated blocks. These results indicated that DOT and CCA-treated wood surfaces were unpreferred substrates for colony foundation by C. brevis , but that these deposits were not toxic to dealates as demonstrated by their survival in neighboring control blocks. In 1996, no-choice tests were conducted using trap blocks partially treated with DOT solution or water (control). Live dealates, heterosexual dealate pairs, and brood were detected in all control treatments at 6 mo. The mean number of nuptial chambers and live termites was not significantly different among the control treatments. The number of nuptial chambers in all DOT treatments, however, was significantly lower compared with control blocks and no live termites were found in any DOT-treated blocks. These results demonstrate that partial DOT deposits deterred C. brevis dealates from colonizing blocks. Choice tests also were conducted in 1996. A silica gel-pyrethrin dust, spinosad suspension concentrate (SC), and DOT dust were applied to trap block tops and tested against control blocks. Significantly fewer nuptial chambers and live termites were found in silica gel-treated blocks compared with neighboring controls. Although the number of nuptial chambers was reduced significantly in spinosad-treated blocks compared with control blocks, there was no significant difference in the number of live termites. No live termites were detected in either DOT-dusted trap blocks or in adjacent control blocks, implying that dealates searching for colonization sites were intoxicated by DOT dust and unable to colonize neighboring control blocks. In remedial control tests, mature colonies of C.brevis and Incisitermes snyderi (Light) in naturally infested wood were exposed to single-point gallery injections of spinosad SC or surface applications of aqueous DOT. Infested wood members were bisected, and the resultant halves differentially treated with chemical or water. Member halves were destructively censused at 28-33 d and 97-109 d after treatment with spinosad and DOT, respectively. Spinosad-treated halves yielded 92-100% mortality in 8 of 9 wood members containing either I. snyderi or C. brevis infestations. Surface applications of DOT caused partial and sporadic mortality. Mortality ranged from 1 to 88% for I.snyderi and was significantly greater overall compared with water-injected halves, whereas mortality in C. brevis infestations treated with DOT ranged from 0 to 35%.Mortality in water-treated half members ranged from 0 to 9%.Results of remedial control tests demonstrate the advantages of intragallery applications over surface-only treatments for drywood termite infestations.

The Extent of Benthic Impacts of CCA-Treated Wood Structures in Atlantic Coast Estuaries

To ascertain the extent of impacts from CCA-treated wood bulkheads, we sampled sediments along 10-m transects from these bulkheads and from reference sites (either bulkheads made of other materials or unbulkheaded areas nearby) and analyzed the fine fraction for metals. We ascertained metal content in resident biota, and analyzed species richness, Shannon-Wiener diversity index, and biomass of the benthic community. We found accumulation of metals in the fine-grained portion of nearby sediments and reduction in the biotic community nearby (generally at 0 and 1 m); such gradients were generally not seen in reference transects. At two of the sites there was evidence for secondary reduction of the community out further to 3 or 10 m, where the metals in the fines were lower but the percent fines was greatly increased. At all the other sites, impacts were generally limited to 0 and 1 m. The lack of reduction at further distances at the other sites is attributed to factors such as the age of the bulkheads, high energy of the environment, or nature of the sediments at those sites.

Removal of CCA from treated wood by oxalic acid extraction, steam explosion, and bacterial fermentation

Most preservative-treated wood produced and consumed in the United States is treated with toxic inorganic compounds containing copper, chromium, and arsenic. Because chromated copper arsenate (CCA) is fixed to the wood, CCA-treated wood has not been considered toxic or hazardous and it is currently disposed of in approved landfills. Growing public concern about environmental contamination from treated wood combined with the removal of greater quantities of CCA-treated wood from service have presented a disposal challenge for this fiber source. In this study, CCA-treated wood was processed by acid extraction, steam explosion, and bacterial fermentation and evaluated for removal of copper, chromium, and arsenic. Copper was the easiest to remove by these treatments and chromium the most resistant to removal. Exposing CCA-treated wood to steady-state bacterial growth by continuous culture with Bacillus licheniformis CC01 did not enhance removal of CCA components compared to standard mixed culture when acid extraction preceded bacterial fermentation. Nor did steam explosion, alone or in conjunction with acid extraction and bacterial fermentation, enhance removal of CCA components; the chromium and arsenic components resisted removal. Grinding CCA-treated wood chips into 20-mesh sawdust provided greater access to and removal of CCA components by all processes. However, grinding the chips was unnecessary if they were treated with acid prior to bacterial fermentation. Extraction with oxalic acid as a precursor to bacterial fermentation with B. licheniformis CC01 removed 90% copper (CuO), 80% chromium (CrO3), and 100% arsenic (As2O5) from treated chips. The combination of acid extraction and bacterial fermentation removed 80–100% of these metals from CCA-treated wood.

Oxidation of Wood Components During Chromated Copper Arsenate (CCA-C) Fixation

Pre-extracted radial sections of southern yellow pine sapwood were treated with CCA-C and analyzed by x-ray photoelectron spectroscopy (xps). The ratio of CI (carbon bonded only to carbon and/or hydrogen) to C2 (carbon bonded to one oxygen with a single bond) was used to determine the progress of oxidation of wood components during CCA fixation. This ratio increased after treating times of 10 minutes and 60 minutes and decreased after 180 minutes soaking suggesting that oxidation of C2 predominates on initial contact with CCA solution but oxidation of CI (lignin) becomes more important with extended exposure to the treating solution. Oxidation of C2 to C3 (carbon bonded to two oxygens or a carbonyl group) was demonstrated by in situ trapping of C3 with ethylene glycol as it was formed. Further oxidation of C3 to C4 (carboxylic carbon) was not observed in the xps spectra, consistent with the findings of others. The hypothesis that rapid decarboxylation results in loss of C4 as evolved CO2 is supported by the observation that the C4 component of untreated wood was reduced by more than 90% after 10 minutes of CCA soaking followed by high temperature fixation and by the observation of CO2 evolution during early stages of accelerated fixation. The Cr(2p) spectra of CrVI and CrIII were established at 580.2 and 577.8 eV respectively. Accelerated fixation of CCA-C treated specimens resulted in a very high degree of reduction of CrVI to CrIII. XPS Cu (2p3/2) peaks were established at 935.1 for CCA-C, 935.3 for Cu(OH)2, and 933.7 for CuO. Cu (2p3/2) peaks in CCA-treated wood were shown at 932.9 with no satellite peaks for the 10-60 minutes soaking in CCA series, and at 933.9 and 936.4 with satellite at 941-948 for the 3 hours soaking time. The latter are attributed to complexed copper oxide and hydroxide forms of CuII. Peaks attributed to CuII hydroxides were shown to diminish in leached samples.

Surface characterization of chromated copper arsenate (CCA)-treated red maple

Red maple wood blocks were treated with chromated copper arsenate (CCA) preservative. The surface quality of both treated and untreated wood was characterized by various analytical techniques. Environmental scanning electron microscopy (ESEM) showed deposits of metal oxides on the cell wall of CCA-treated wood. X-ray photoelectron spectroscopy (XPS) indicated a higher oxygen/carbon ratio on the surface for CCA-treated wood than for untreated controls or water-treated samples. The surface of CCA-treated wood was rougher than that of untreated and water-treated wood. Higher contact angles for CCA-treated wood with water, glycerol, and phenol-formaldehyde adhesive compared with untreated wood indicated poor wettability and a hydrophobic surface, which may partially explain why composites made of CCA-treated wood exhibit low performance, particularly in exterior applications.