Kinetics and Mechanism of Fixation of Cu-Cr-As Wood Preservatives. Pt. I. pH Behaviour and General Aspects on Fixation

Dahlgren, Sven-Eric; Hartford, Winslow H.

doi:10.1515/hfsg.1972.26.2.62

Cited by 52 publications

(21 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Upon contact of the CCA solution with the wood, a series of fixation reactions is initiated. Pizzi [3][4][5][6][7] and Dahlgren [8][9][10] proposed mechanisms describing this process and their work was recently summarised by Humphrey [2] as: (i) adsorption of Cr(VI) (as HCrO 4 À ) onto functional groups in the wood structure; (ii) the slow reduction of Cr(VI) to Cr(III); (iii) complexation of Cu 2+ with lignin and holocellulose; and (vi) formation of precipitates, e.g., CrAsO 4 and Cr(VI) oxides. Other compounds, including CuCrO 4 and Cu 3 (AsO 4 ) 2 , are possible in the final product through the combination of Cr(VI), Cu(II), and As(VI).…”

Section: Chromated Copper Arsenatementioning

confidence: 99%

Formation of dioxins and furans during combustion of treated wood

Tame

Dlugogorski

Kennedy

2007

Progress in Energy and Combustion Science

108

View full text Add to dashboard Cite

Section: Chromated Copper Arsenatementioning

confidence: 99%

Formation of dioxins and furans during combustion of treated wood

Tame

Dlugogorski

Kennedy

2007

Progress in Energy and Combustion Science

108

View full text Add to dashboard Cite

“…The hexavalent chromium in the preservative solution fixes or binds the arsenic and copper to the wood. The reduction of Cr(VI) to Cr(III) in the wood fiber matrix results in the formation of many sparingly soluble precipitates, including CrAsO 4 , Cu(OH)CrAsO 4 , CuCrO 4 , and other wood-chromium complexes (Dahlgren and Hartford, 1972;Greaves, 1974;Bull et al, 2000). The bulk of the fixation process occurs within a few days, with the rate of chromium fixation depending on environmental factors such as temperature (Cooper et al, 1997).…”

Section: Introductionmentioning

confidence: 99%

Hexavalent Chromium Reduction in Soils Contaminated with Chromated Copper Arsenate Preservative

Song

Townsend

Solo‐Gabriele

et al. 2006

Soil and Sediment Contamination: An International Journal

View full text Add to dashboard Cite

The toxicity and mobility of chromium in the environment greatly depends upon its speciation. The reduction of hexavalent chromium to trivalent chromium in a soil environment was examined by spiking three soil types (sandy, clayey, and organic soils) with a common wood preservative solution known as chromated copper arsenate (CCA). Chromium in the CCA preservative solution exists in the hexavalent form. The total and hexavalent chromium concentrations (mg/kg) were measured over a period of 11 months. Leachable chromium concentrations (mg/L) were assessed using the synthetic precipitation leaching procedure (SPLP). The degree and rate of hexavalent chromium reduction were similar for the sand and clayey soil, but much greater for the organic soil. Most of the chromium reduction occurred within the first month of the experiment. At the end of the experiment, approximately 50% of the hexavalent chromium was converted to the trivalent form in the sand and clayey soils. Hexavalent chromium concentrations were below detection in the organic soil at the end of the experiment. Nearly all of the chromium observed in the SPLP leachates was in the form of hexavalent chromium. Chromium leaching was thus greatest in the sand and clay soils where the hexavalent chromium persisted. The results indicate that hexavalent chromium in soils can persist for considerable time periods, in particular in soils with low organic matter content.

show abstract

“…Studies on the preservation do not supply wide and exhaustive information on this subject since generally the formulations are investigated as a whole (Nicholas and Preston 1984). By treating wood with a preservative formulation, for instance CCA namely Chromated Copper Arsenate, a decrease of the pH value occurs (Dahlgren and Hartford 1972;Pizzi 1982;Cooper and Ung 1992). This change is attributed to cation exchange reactions of copper and specific wood components as suggested indirectly by anatomical examinations with colorimetric techniques (Bland 1963).…”

Section: Introductionmentioning

confidence: 99%