Study on Hazard Analysis of Chromium-leached for CCA-Treated Wood

• Main Authors: Pie-Hua Wu, 巫沛華
• Other Authors: Wen-Tien Tsai
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/25512996406372265725

碩士 === 國立屏東科技大學 === 木材科學與設計系所 === 99 === Chromated copper arsenate (CCA) is a common wood preservative. However, Taiwan has banned the use of the product for some constructions on April 1, 2007 because it is a human carcinogen and possibly poses a potential risk to groundwater. As a result, CCA-treated wood as a solid waste will be concerned with its treatment and disposal in the current and future. In the present study, the experimental CCA-treated wood materials were tested using the toxicity characteristic leaching procedure (TCLP) and isothermal shaking water bath test leaching procedure to identify chromium concentrations by colorimetric and inductively coupled plasma-mass spectrometry (ICP-MS) methods. It was found that all of leached chromium concentrations were below the official standard designated by the Environmental Protection Administration. Furthermore, the results of the leaching experiments showed that the pH of the leachants, and density and particle size of CCA-treated woods have significant effects on the leaching process, higher leached metal concentrations in light and small size woods and low pH environment. Based on the experimental results, it was suggested that the CCA-treated woods should be separated from woody waste. The segregated CCA-treated woods were further treated using extraction to reduce their toxic metal hazards prior to the recycling or the reuse as energy sources.