Changes in Cr speciation in unfiltered leachates (pH 6.5–6.9) from the bleach/scrub method showed that CrVI concentrations either stabilized or declined over a Cabergoline of 11 d as CrVI reduction to CrIII occurred (Fig. 3). However, the CrVI concentration in leachate from sample D continued to increase, reaching 832 μg/L after 11 d. Taylor et al. (2001) reported that bleach containing sodium hypochlorite (NaClO) and sodium percarbonate (Na2CO3·1.5H2O2) resulted in accelerated Cr leaching from CCA-wood, with up to 62% being CrVI. Maas et al. (2002) tested the effect of three wood cleaning products on CrVI formation in leachate from 8.5-year old CCA-wood, showing disodium peroxydicarbonate (C2Na2O6) and NaClO producing up to 160 μg/L CrVI.
Fig. 3. Changes in CrVI concentrations in unfiltered leachates over an 11-d period from six pieces of CCA-wood that were cleaned using the bleach/scrub method.Figure optionsDownload full-size imageDownload as PowerPoint slide