Speciation of arsenic and chromium in the leachate from chromated copper arsenate (CCA) type C treated southern pine (Pinus spp.)

Abstract

Abstract A 558-h laboratory leaching test (AWPA E-11) was carried out on both commercially and laboratory chromated copper arsenate (CCA) type C-treated southern pine. Arsenic, chromium, and copper concentrations in the leachate collected were examined. Leaching of chromium and copper from CCA-treated wood cubes were nearly undetectable using flame atomic absorption spectroscopy after 174 and 366 h, respectively. Less than 10% of the total chromium in the leachate was present as hexavalent chromium [Cr(VI)] after leaching for 30 h. Selective ion-exchange chromatography was used to speciate arsenic in the leachate. In the first 270 h, approximately 70–90% of the total arsenic in the leachate was inorganic pentavalent arsenic [As(V)] and 10–30% was inorganic trivalent arsenic [As(III)].