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• 1. [Article] Interactions of ammoniacal copper zinc arsenate (ACZA) with Douglas-fir

  Tests were conducted to determine the effect of ACZA composition on fixation and the roles of adsorption and precipitation in fixation. The sites of copper and zinc adsorption within the treated wood and ...

  Citation × Citation Citation Abstract Copy Title: Interactions of ammoniacal copper zinc arsenate (ACZA) with Douglas-fir Author: Lebow, Stan T., Morrell, Jeffrey J. Tests were conducted to determine the effect of ACZA composition on fixation and the roles of adsorption and precipitation in fixation. The sites of copper and zinc adsorption within the treated wood and the bonding environment of adsorbed copper were also examined. The results generally support the finding that arsenic fixation occurs by precipitation of metal/arsenate complexes. Arsenic leaching was minimized with high solution ratios of metal oxide:arsenic pentoxide, and with formulations containing zinc. Zinc precipitated the majority of arsenic when ammonia was allowed to evaporate from the treating solution. The metal cations were leach-resistant regardless of ACZA formulation because of their low water solubility and their ability to adsorb to the wood. Copper was readily adsorbed by lignin and by model compounds that possessed phenolic hydroxyl groups, which suggests that phenolic hydroxyl groups were the primary reaction sites. Fourier Transform Infrared (FTIR) and Fast Atom Bombardment (FAB) mass spectroscopy analysis also supported this conclusion. Multiple copper species and increased free radical content were detected within lignin that had adsorbed copper. Adsorption of copper and zinc has important ramifications for arsenic fixation. Title: Interactions of ammoniacal copper zinc arsenate (ACZA) with Douglas-fir Author: Lebow, Stan T., Morrell, Jeffrey J. Tests were conducted to determine the effect of ACZA composition on fixation and the roles of adsorption and precipitation in fixation. The sites of copper and zinc adsorption within the treated wood and the bonding environment of adsorbed copper were also examined. The results generally support the finding that arsenic fixation occurs by precipitation of metal/arsenate complexes. Arsenic leaching was minimized with high solution ratios of metal oxide:arsenic pentoxide, and with formulations containing zinc. Zinc precipitated the majority of arsenic when ammonia was allowed to evaporate from the treating solution. The metal cations were leach-resistant regardless of ACZA formulation because of their low water solubility and their ability to adsorb to the wood. Copper was readily adsorbed by lignin and by model compounds that possessed phenolic hydroxyl groups, which suggests that phenolic hydroxyl groups were the primary reaction sites. Fourier Transform Infrared (FTIR) and Fast Atom Bombardment (FAB) mass spectroscopy analysis also supported this conclusion. Multiple copper species and increased free radical content were detected within lignin that had adsorbed copper. Adsorption of copper and zinc has important ramifications for arsenic fixation. Close