• Environmental Analysis Health and Toxicology
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• v.22 no.4
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• pp.339-348
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• 2007

A laboratory experiment was conducted to study the characteristics of leaching of Cr, Cu, and As from chromated topper arsenate (CCA)-treated wood. The wood species tested was hemlock spruce ($10\;cm\;{\times}\;10\;cm\;{\times}\;10\;cm\;tube$). The leaching experiment was conducted over 60 days using I L of leachants whose pHs were adjusted to 2.0, 3.7, and 1.6, respectively with nitric acid, and also using lake water, according to the OECD guideline. Each leachate was analyzed for Cr and Cu using flame-AAS, and for As using vapor generation-AAS. Three metals were loathed at the highest levels at pH 2.0 but almost at similar levels at the other conditions. Cumulative quantifies over 60 days of a leaching period were in order of As>Cu>Cr. As was predicted to leach with an increase in flux over a 10 year period, while Cr and Cu fluxes were predicted to decrease with time. This result suggest that arsenic can pose a health risk to humans over a long period of time, when CCA-treated wood is used for building facilities (e.g., playgrounds, residential purposes, etc.) with which humans frequently contact.

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.340-346
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• 2009

Chromated copper arsenate (CCA) is a chemical wood preservative that has been intensively used to protect wood from decay during the last few decades. CCA is widely used to build structures such as decks, fences, playgrounds and boardwalks. However, structures constructed of CCA-treated wood have caused adverse environmental effects due to leaching of Cr, Cu and As into surrounding soils. This research was conducted to monitor the vertical and horizontal distribution of Cr, Cu and As in soils adjacent to CCA-treated wood structures in Korea. Two structures constructed with CCA-treated wood were selected at Hongcheon and Chuncheon in Gangwon Province, South Korea. Eleven soil profile samples were collected at depths of 0 to 80 cm at each site, while 12 surface soil samples were collected at distances of 0 to 200 cm from each structure. The soil chemical properties, soil particle size distribution and total metal concentrations were then determined. The results revealed that soils near CCA-treated wood structures were generally contaminated with Cr, Cu and As when compared to the background concentration of each metal. In addition, the concentrations of Cr, Cu and As in soils decreased as the vertical and horizontal distance from the structure increased. Further studies should be conducted to evaluate the mobility and distribution of these metals in the environment as well as to develop novel technologies for remediation of CCA contaminated soils.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.60-67
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• 2010

Although several studies have reported that Cr, Cu and As can leach from CCA-treated woods, few studies have been conducted on this topic in Korea. Therefore, this study was conducted to monitor Cr, Cu and As leaching from CCA-treated wood products and to develop a rapid identification method for CCA-treated wood products by using indicators such as PAN stain. Soil samples were collected at depths of 0-70 cm and wood samples were collected by thickness of wood layer. The soil and wood samples were then digested and analyzed for Cr, Cu and As concentrations using an atomic absorption spectrometer. The As and Cu concentrations decreased sharply with depth from 34.38 and 33.65 mg $kg^{-1}$ at 0-1 cm to 1.72 and 7.84 mg $kg^{-1}$ at 70 cm, respectively. In general, As was more mobile than Cr and Cu in the soil. For wood samples, the Cr, Cu and As concentrations were higher in the outer layer (0-0.5cm) than the inner layers (0.6-4.5cm). Evaluation of rapid identification methods revealed that 100% acetone with 0.1% PAN indicator was the best combination for detection of CCA-treated wood in the field.

• Journal of Soil and Groundwater Environment
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• v.11 no.1
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• pp.54-64
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• 2006

Chromated copper arsenate (CCA), a wood preservative, has been widely used to protect wood products from attacks by bacteria, fungi and insects. However, the use of CCA is currently forbidden or limited to some applications in many countries because the toxic elements (Cr, Cu, and As) of CCA are released into the environments during outdoor uses, which may cause adverse health effects on humans and ecological systems. This study was conducted to investigate the distributions of chromium, copper and arsenic in soils adjacent to two CCA-treated wood structures. In a 7 month old pond entry structure, ten surface soil samples (0-2.5 cm) were collected at lateral distances of 0, 0.5, and 1 m from the stairway, and nine surface soil samples were collected beneath the deck. Nine top soil samples were taken from a 2 year old sound barrier structure at lateral distances of 0, 1, and 2 m. Background surface soil samples were also collected from each structure. Samples were analyzed for some physicochemical properties such as pH, electrical conductivity, organic matter content, and soil texture. Following the extraction of the elements with a microwave digestion system, samples were analyzed for Cr, Cu, and As. The concentrations of the three elements in soils adjacent to the structures were significantly elevated compared to the background levels, indicating that the elements have been leached out of the structures. Released e1ements showed lateral concentration gradients within 1 m. The elevations of the three elements in soils underneath the deck did not seem different (background-corrected concentrations: Cr, 5.01 mg/kg; Cu, 5.50 mg/kg; As, 4.91 mg/kg), while the elements in soils near the sound barrier were elevated in the order of As>Cu>Cr with measured concentrations of 49.7, 44.7 and 52.5 mg/kg, respectively. Background As, Cu, and Cr concentrations near the sound barrier were 9.88, 30.8, and 46.5 mg/kg, respectively. These results showed that CCA constituents are released into the environment and it is suggested that risk assessment need to be conducted to investigate harmful effects of the released elements on humans and ecological systems.

• Journal of the Korean Wood Science and Technology
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• v.37 no.2
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• pp.137-140
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• 2009

Chromated copper arsenate (CCA), a long history of successful preservative, have raised environmental concerns. Adsorption characteristics of domestic soils for chromium, copper, and arsenic were assessed by measuring distribution coefficient ($K_d$) values of these metal components in a laboratory scale. The results revealed that $K_d$ values were higher in chromium, followed by arsenic and copper in soil matrix. Different soil matrixes resulted in varying mobilities of CCA components. The values of $K_d$ for all three metals increased with organic matter contents. The results suggest that the mobility of metal components may be very limited to the surface area adjacent to CCA-treated wood due to their fairly large distribution coefficient ($K_d$). However, the metal components would be persistent and accumulated in the soil, resulting in high chemical concentration in service area of treated wood.

• Journal of the Korean Wood Science and Technology
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• v.35 no.1
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• pp.73-80
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• 2007

This study was carried out to separate the heavy toxic metals in eco-building materials by low-temperature pyrolysis, especially arsenic (As) compounds in CCA wood preservative as a solid in char. The pyrolysis was carried out to heat the CCA-treated Hemlock at $280^{\circ}C$, $300^{\circ}C$, $320^{\circ}C$, and $340^{\circ}C$ for 60 mins. Laboratory scale pyrolyzer composed of [preheater$\rightarrow$pyrolyzer$\rightarrow$1st water scrubber$\rightarrow$2nd bubbling flask with 1% $HNO_3$ solution$\rightarrow$vent], and was operated to absorb the volatile metal compound particulates at the primary water scrubber and the secondary nitric acid bubbling flask with cooling condenser of $4^{\circ}C$ under nitrogen stream of 20 mL/min flow rate. And the contents of copper, chromium and arsenic compounds in its pyrolysis such as carbonized CCA treated wood, 1st washing and 2nd washing liquors as well as its raw materials, were determined using ICP-AES. The results are as follows : 1. The yield of char in low-temperature pyrolysis reached about 50 percentage similar to the result of common pyrolytic process. 2. The higher the pyrolytic temperature was, the more the volatiles of CCA, and in particular, the arsenic compounds were to be further more volatile above $320^{\circ}C$, even though the more repetitive and sequential monitorings were necessary. 3. More than 85 percentage of CCA in CCA-treated wood was left in char in such low-temperature pyrolytic condition at $300^{\circ}C$. 4. Washing system for absorption of volatile CCA in this experiment required much more contacting time between volatile gases and water to prevent the loss of CCA compounds, especially the loss of arsenic compound. 5. Therefore, more complete recovery of CCA components in CCA-treated wood required the lower temperature than $320^{\circ}C$, and the longer contacting time of volatile gases and water needed the special washing and recovery system to separate the toxic and volatile arsenic compounds in vent gases.

• Journal of the Korean Wood Science and Technology
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• v.13 no.2
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• pp.35-44
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• 1985

The purposes of this study were, first, to investigate retention levels of toxic elements and oxide individual plies for each panel and, second, to examine disproportioning of individual toxic elements Thirty five water gum plywood panels were treated with a copper-chromium-arsenic preservative (CCA) by the soaking process as the treament time were applied. Such individual plies at a distance of 2.5cm, 7.5cm from the edge were assayed for CuO, $CrO_3$, and $As_2O_5$ on the basis of copper, chromium and arsenic content by Atomic Absorption Spectrophotometry. In these experiments, 12mm thickness plywood panels made of water gum, which were selling, were selected for the preservative treatment. Treating solutions were prepared for 10%, dilute solution of copper-chromium-arsenic preservative and then 1, 3, 6, 12 and 24 hours soaking trements in CCA preservative were applied. The results obtained are as follows: 1. The retention of total oxide in the face and back plies (1+7) retained more than the retention of total oxide in the other plies. The total oxide retention for the individual plies except the face and back plies (1+7) was showed in the following orders; cross plies (3+5), cross plies (2+6), core ply (4). 2. The retentions of total oxide increased as the increase of treatment time. The CCA treated plywood retained high levels of total oxide retention in the face and back plies (1+7). 3. All the retentions in the face and back plies (1+7) is over 5Kg/$m^3$, New Zealand Timber Preservation Standards Specification, and after 6 hours, the retentions in the cross plies (3+5) is over 4. The relative penetration of copper, chromium, and arsenic were not affected by the treatment time. The proportion of arsenic decreased in relation to both copper and chromium and the proportion of copper increased in relation to both chromium and arsenic. 5. A disproportioning of copper, chromium occurred with longer distance from edge, and with longer distance from edge the leachability resistance of CCA treated specimens decreased. After 6 hours (soaking time), the proportion of active elements at a distance of 2.5cm from the edge was consistent. And after 24 hours-soaking, the proportion of active elements at a distance of 7.5cm from the edge was consistent.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.11
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• pp.1102-1110
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• 2008

This research was performed to analyze the characteristics of wood wastes from origin and to suggest grade-classification for them. Korean proximate analysis was conducted, and heating value, heavy metals and Cl concentrations were analyzed for gradeclassification. Wood wastes were sampled from forest, living, construction and demolition, and industrial areas with origin. Moisture content of most wood wastes was ranged in 5$\sim$10%. VS (volatile solids) and ash contents of them showed > 95% and < 5%, respectively. Most wood wastes except wood for growing mushroom permitted the standard (low heating value $\geq$ 3,500 kcal/kg) for refusederived fuel. CCA (Cr, Cu, As) concentration of wood wastes used in bench, wasted fishing boat, and railroad crosstie was higher than that of the other ones. Cl content showed approximately 1.3% in wood box for fish and $\leq$ 0.2% in the other wood wastes. Cl content of all wood wasted used in this research permitted the standard (Cl $\leq$ 0.2%, dry weight basis) for refuse-derived fuel. If the wood wastes were classified in 3-grade, plywoods would be in 2nd grade, and MDF (medium density fiber), wooden bench, painted electric wire drum, wasted fishing boat, and railroad crosstie be in 3rd grade.