• Journal of the Korean Wood Science and Technology
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• v.33 no.6 s.134
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• pp.87-94
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• 2005

This study was carried out to investigate the effect of soil types and soil properties on wood preservative leaching. Radiata pine (Pinus radiata Don.) sapwood stakes, which had been treated with 2.0%(w/v) CCA, were leached for 12 weeks by a common laboratory method in four different soils and for 14 days by the AWPA standard leaching method in water. The physical and chemical properties of the four soils were determined, and the percent leaching of the individual component of CCA was correlated with the various soil properties. The data show that leaching of preservative chemicals from treated wood exposed to soil is influenced by the type of soil. The preservative leaching was greater when wood was exposed to water than when the wood was in contact with water-saturated soil. The greatest chromium, copper and arsenic leaching from CCA-treated stakes were observed in the sandy loam, loam, and sand, respectively, and the least amount of leaching of CCA components occurred in the silty loam. The leaching of preservative components from treated wood is extremely complex and appears to be influenced differently by the soil properties. The extent of copper leaching from CCA treated wood appears to be related to exchangeable Mg and sum of bases. There is a reasonably good relationship between chromium leaching and exchangeable Mg, and between arsenic leaching and exchangeable K, soil Ni, Mn, Fe, Cr, or Cu content. Since this study was conducted based on laboratory leaching method using small cross-sectional dimensions; thus, data obtained from this experiment should not be used to predict leaching characteristics from commercial-size wood used in real situation. Accordingly, further studies are necessary using outdoor ground-contact leaching.

• Journal of the Korean Wood Science and Technology
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• v.19 no.2
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• pp.65-71
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• 1991

본 연구는 CCA 처리재의 재건조(再乾燥)시 적용된 건조 스케쥴 (통상(通常) 열기건조(熱氣乾燥)와 고온건조(高溫乾燥) 스케쥴)이 처리재의 휨강도(强度) 성질에 미치는 영향을 고찰하고자 수행되었다. 탄성계수(彈性係數)(MOE), 그리고 비파괴시험(非破壞試驗)에 의해 얻어진 동적(動的) 탄성계수 (Dynamic MOE) 및 대수감쇠율(對數減衰率)(Logarithmic decrement) 은 처리후 재건조에 의해 큰 영향을 받지 않았다. 반면에 적용된 건조 스케쥴에 관계없이 재건조시 심각한 파괴계수(破壞係數)(MOR)의 감소가 파괴계수 분포의 모든 영역에서 초래되었다. 그러나 통상 열기건조(최대 건구온도=$71^{\circ}C$)와 고온건조(건구온도=$110^{\circ}C$) 서로간에는 감소의 정도에 큰 차이가 없었다. 따라서, 처리재의 재건조사 심각한 파괴계수의 감소가 용인(容認)되지 않는다면 CCA로 처리된 Lodgepole pine 각재의 재건조는 미국 연방 임산물 시험장의 Lodgepole pine의 통상 열기건조 스케쥴 (T9-C3) 보다 온화(溫和)한 조건으로 실시되어야 할 것이다.

• Proceedings of the KWS Conference
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• 1999.05a
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• pp.285-287
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• 1999

• Journal of Korea Foresty Energy
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• v.23 no.2
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• pp.29-33
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• 2004

This study was carried out to find out safety disposal methods of waste CCA treated wood. The heavy metals of remnant were analyzed after combustion of CCA treated wood at different temperatures. Arsenic volatilized temperature was detected. The removal rate of heavy metals by acid in the ash were examined. Through this study, we could conclude that in order to protect volatilize arsenic, combustion of CCA treated wood should be do under the $300^{\circ}C$. But when CCA treated wood combustion under $300^{\circ}C$, it's weight-loss rate was $55\%$, so land reclamation dependence will be increased. When CCA treated wood combustion at high temperature, the land reclamation dependence could be reduced, but the arsenic that volatilize into the atmosphere should be captured. When it bums with high temperature, the ash contains lots of copper and chromium, so removal of heavy metals should be conducted.

• Korean Journal of Agricultural Science
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• v.22 no.1
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• pp.42-48
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• 1995

With the aim to investigation of decay resistance and optimum concentration in chrome-copper-arsenic(CCA) preservative treatment on the imported softwoods from Siberia and North america, preservative absorption after CCA impregnation, weight losses and degradation patterns by decay fungi were examined. The density and latewood rate of Siberia softwoods(Spruce and Larch) were higher than those of North america softwoods(Douglas-fir and Western hemlock), resulting in the decrease of the CCA preservative absorption in the Siberia softwoods. In the case of untreated softwoods, decay resistance against Coriolus versicolor was lower than against Tyromyces palustris. For CCA treated softwoods, preservative effectiveness increased with increase in concentration of CCA solution. When treated with 0.7% CCA solution, efficiency value was more than 80 and 90 for C. versicolor and T. palustris, respectively. From this results, in the CCA preservative treatment for imported softwoods, it can be concluded that optimum concentration of CCA solution is approximately 0.7%. The absorption of CCA preservative distributed in the range of 3.8 and $5.5kg/m^3$. After exposure to testing fungi, in the untreated softwoods, bore holes formed in the cell walls and bordered pits, moreover, bordered pit canals enlarged by the fungi. However, 0.5% CCA treated softwoods was almost no deterioration in the cell walls and bordered pits due to decay.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.528-536
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• 2002

As one step for the safety performance of LNG storage tank, the change in fracture toughness within the X-grooved weld heat-affected zone (HAZ) of newly developed 9% Ni steel, which was submerged arc (SA)-welded, was investigated. Both crack initiation fracture toughness and crack arrest fracture toughness were evaluated by the crack tip opening displacement (CTOD) tests and compact crack arrest (CCA) tests. As the evaluated region approached the fusion line, each test result shorted different tendency, that is, crack initiation toughness decreased while crack arrest toughness increased. The results were discussed through the observation of the microstructural change.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.48-53
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• 2014

Rocket, held using the CCA for the mission, a plurality of recording devices, and navigation equipment. In case of a projectile which is entered the water after fired into the air, after performing stages and fairing separated in flight to enter the underwater. It is caused by the explosion of gunpowder mainly, vibration phenomenon of a large transition is induced structurally very, also on entering the water, have a significant shock structurally separated. If shock is transmitted directly to the CCA through the body, it can be caused malfunction of payloads, resulting in failure of the mission of the projectile. In order to ensure the stability against shock, in this paper, Calculating a target resonacne frequency of the CCA, and verified through modal test and analysis. Maximum acceleration position of CCA is checked by SRS analysis. In addition, effectiveness of shock isolation system through shock analysis.

• Journal of the Korean Wood Science and Technology
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• v.33 no.6 s.134
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• pp.95-100
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• 2005

The using amount of preservative-treated wood equipments has been increased. Specially, chromate copper arsenate (CCA) has been widely used to exterior wood. We are faced to the disposal problem after service period of CCA treated wood due to its toxic heavy metals. For the disposal of end-used treated wood, land-filling and incinerating methods are mainly applied. The essential problem of incinerating is an arsenic release into atmosphere. Low pyrolysis is suggested as the methods of protecting arsenic release during incineration. The heavy metals were recovered after combustion of the treated wood at the low temperature which arsenic can not released. The recovery amounts of effectiveness compounds was determined in various solvents (citric acid, nitric acid, sulfuric acid, acetic acid, phosphoric acid) and different temperature (300, 400, $500^{\circ}C$). The higher temperature was applied, the more copper was recovered. The chromium was difficult to be recovered on the carbonized CCA treated wood at 0.5% acid concentration. The recovery mass of arsenic decreased on the higher combustion treated wood. The recovery of chromium was difficult due to the chemical change of the chromium arsenate during pyrolysis.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1071-1079
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• 2011

In this study, coal combustion ash (CCA) was evaluated for its stabilization effect on acidic mine waste with column experiment. Total of six treatments were installed depending on mixing ratio between coal wastes and CCA (0, 20, 40%) and mixing method (completely mixing and layered). Artificial acidic rain (pH 5.6) was used for feeding solution with flow rate of $0.05mL\;min^{-1}$. Result showed that higher pH of leachate was observed as more CCA was mixed. The highest pH in leachate was measured when 40% of CCA was mixed with coal waste (pH of 5.8). Also, complete mixing with CCA and coal waste was more effective to increase the pH of leachate than layered treatment. Regarding the reduction of soluble Fe amount, the highest efficiency (78%) was observed when 20% of coal ash was completely mixed with mine waste. Based on those result, optimum mixing ratio of coal ash with mine waste can be ranged 20-40% depending on environmental circumstances in the field.

• Journal of the Korean Wood Science and Technology
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• v.39 no.6
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• pp.481-489
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• 2011

This study was conducted to evaluate the pressure treatment characteristics of Japanese red pine and Japanese larch skin timber with ACQ-2, CUAZ-2 and CuHDO-1. The effect of moisture content (MC) on preservative treatability was investigated for Japanese red pine sapwood and Japanese larch heartwood, and fixation characteristics of CCA alternatives was also evaluated. Japanese red pine sapwood, which was dried below 30 percent MC, was fully penetrated with preservatives, and minimum requirement of preservative retention for the hazard class H3 was achieved. Through measuring preservative retention gradient in Japanese red pine sapwood, it was confirmed that the retention gradient of CuHDO-1 was steeper than that of both ACQ-2 and CUAZ-2. In particular, it was intensified at a higher MCs of wood samples (25∼30%). Japanese larch heartwood did not meet the minimum requirement of penetration and retention for the hazard class H3 over the range of pretreatment MCs tested. With presteaming under $121^{\circ}C$ for 12 hours, the treatability of Japanese larch heartwood was enhanced to meet the minimum requirement for the hazard class H3. The fixation rate of copper was much more faster under drying condition compared with nondrying condition; more than 95% of copper were fixed in 3~6 days and 1 day under drying conditions in Japanese red pine sapwood and Japanese larch heartwood, respectively. After 3-week fixation period at ambient temperature, the amount of mobile copper in treated wood sample that remains available for leaching from treated wood was the highest in the wood samples treated with ACQ-2, followed by CuHDO-1 and CUAZ-2. It was proportional to the amount of copper in treating solution.