• Title/Summary/Keyword: 방부

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The Heavy Metals Recovery from Carbonized CCA Treated Wood (CCA방부목재의 탄화가 중금속 회수에 미치는 영향)

  • Son, Dong-won;Cheon, Seon-Hae;Lee, Myung Jae;Lee, Dong-heub
    • 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.

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Strength Property of the Incised Larix (Larix kaempferi Carr.) Round Posts treated with CCA (인사이징 처리 낙엽송 CCA-방부원주목의 강도 성능 평가)

  • Park, Jun-Chul;Kim, Sang-Woo;Ryu, Jae-Yun;Hong, Soon-Il
    • Journal of the Korean Wood Science and Technology
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    • v.36 no.3
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    • pp.85-92
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    • 2008

  • Strength of logs and round posts is compared and analyzed to estimate the strength of the incised Larix round posts treated with CCA in this paper. There is no significant difference in MOR of logs and round posts. However, in the incised Larix round posts treated with CCA MOE is decreased to about 9%, and there is 29% reduction in MOR as strength ratio is 0.71. When calculating the allowable bending stress of incised round type round posts, not in nominal 2-in timbers, an adjustment factor for MOE and bending strength is proposed as 0.91 and 0.71, respectively. Logs, round posts and the incised Larix round posts treated with CCA do not show significant difference in nail withdrawal load. There is almost no difference between incised Larix round posts treated with CCA and round posts in the shear strength of bolted joint. When calculating the allowable shear stress of bolted joint, it is conformed that considering the application of incising factor is not necessary.

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