Removal of copper, chromium and arsenic from preservative-treated wood by chemical extraction-fungal bioleaching.
Large volumes of preservative-treated wood containing toxic Cr, Cu and As salts are decommissioned worldwide. This study investigated the effectiveness of solid-state fermentation with copper-tolerant brown-rot fungi for the remediation of wood treated with chromated copper arsenate (CCA) and acid copper chromate (ACC) formulations. Treatment of CCA- and ACC-wood with the most effective strain, Antrodia vaillantii FRLP-14G, attained extensive leaching of As and/or Cr, but Cu elimination was poor (<18%). Additional research showed that a variety of organic acids, including citrate, are effective Cu extractants. Based on these findings, a process combining chemical extraction and subsequent fungal treatment was developed that proved highly effective in removing inorganic pollutants from CCA-wood. Extraction of CCA-wood with citric acid (30 mM, pH 3.10) followed by a 28-day solid-state fermentation period removed 87% Cu, 80% Cr, and 100% As. These results indicate the potential of the two-stage process for the remediation of preservative-treated wood.
Sierra-Alvarez
Reyes
R
Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ 85721-0011, USA. rsierra@email.arizona.edu
D055491:Antrodia / Q000378:metabolism*; D001149:Arsenates / Q000378:metabolism; D001151:Arsenic / Q000302:isolation & purification* / Q000378:metabolism; D002857:Chromium / Q000302:isolation & purification* / Q000378:metabolism; D017608:Chromium Compounds / Q000378:metabolism; D003300:Copper / Q000302:isolation & purification* / Q000378:metabolism; D005285:Fermentation; D055441:Poria / Q000378:metabolism*; D014934:Wood / Q000032:analysis* / Q000382:microbiology
D001149:Arsenates; D017608:Chromium Compounds; D002857:Chromium; C040890:chromated copper arsenate; D003300:Copper; C028801:chromium trioxide; D001151:Arsenic; C030973:cupric oxide