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In addition to the combustion of vegetation, fires at the wildland-urban interface (WUI) burn structural mate-rials, including chromated copper arsenate (CCA)-treated wood. This study identifies, quantifies, and charac-terizes Cr-, Cu-, and As-bearing incidental nanomaterials (INMs) in WUI fire ashes collected from three residential structures suspected to have originated from the combustion of CCA-treated wood. The total elemental concentrations were determined by inductively coupled plasma-time of flight-mass spectrometry (ICP-TOF-MS) following acid digestion. The crystalline phases were determined using transmission electron micro-scopy (TEM), specifically using electron diffraction and high-resolution imaging. The multi-element single particle composition and size distribution were determined by single particle (SP)-ICP-TOF-MS coupled with agglomerative hierarchical clustering analysis. Chromium, Cu, and As are the dominant elements in the ashes and together account for 93%, 83%, and 24% of the total mass of measured elements in the ash samples. Chromium, Cu, and As phases, analyzed by TEM, most closely match CrO3, CrO2, eskolaite (Cr2O3), CuCrO2, CuCr2O4, CrAs2O6, As2O5, AsO2, claudetite (As2O3, monoclinic), or arsenolite (As2O3, cubic), although a bona fide phase identification for each particle was not always possible. These phases occur predominantly as het-eroaggregates. Multi-element single particle analyses demonstrate that Cr occurs as a pure phase (i.e., Cr oxides) as well as in association with other elements (e.g., Cu and As); Cu occurs predominantly in association with Cr and As; and As occurs as As oxides and in association with Cu and Cr. Several Cr, Cu, and As clusters were identified and the molar ratios of Cr/Cu and Cr/As within these clusters are consistent with the crystalline phases identified by TEM as well as their heteroaggregates. These results indicate that WUI fires can lead to significant release of CCA constituents and their combustio

The physico-chemical factors affecting the distribution, behavior and speciation of chromium (Cr), copper (Cu) and arsenic (As) was investigated at a former wood impregnation site (Fredensborg, Denmark). Forty soil samples were collected and extracted using a sequential extraction technique known as the Chemometric Identification of Substrates and Element Distributions (CISED) and a multivariate statistical tool (redundancy analysis) was applied. CISED data was linked to water-extractable Cr, Cu and As and bioavailable Cu as determined by a whole-cell bacterial bioreporter assay. Results showed that soil pH significantly affected the solid phase distribution of all three elements on site. Additionally, elements competing for binding sites, Ca, Mg and Mn in the case of Cu, and P, in the case of As, played a major role in the distribution of these elements in soil. Element-specific distributions were observed amongst the six identified soil phases including residual pore salts, exchangeable, carbonates (tentative designation), Mn-Al oxide, amorphous Fe oxide, and crystalline Fe oxide. While Cr was strongly bound to non-extractable crystalline Fe oxide in the oxic top soil, Cu and notably, As were associated with readily extractable phases, suggesting that Cu and As, and not Cr, constitute the highest risk to environmental and human health. However, bioavailable Cu did not significantly correlate with CISED identified soil phases, suggesting that sequential extraction schemes such as CISED may not be ideally suited for inferring bioavailability to microorganisms in soil and supports the integration of receptor-specific bioavailability tests into risk assessments as a complement to chemical methods.

The physico-chemical factors affecting the distribution, behavior and speciation of chromium (Cr), copper (Cu) and arsenic (As) was investigated at a former wood impregnation site (Fredensborg, Denmark). Forty soil samples were collected and extracted using a sequential extraction technique known as the Chemometric Identification of Substrates and Element Distributions (CISED) and a multivariate statistical tool (redundancy analysis) was applied. CISED data was linked to water-extractable Cr, Cu and As and bioavailable Cu as determined by a whole-cell bacterial bioreporter assay. Results showed that soil pH significantly affected the solid phase distribution of all three elements on site. Additionally, elements competing for binding sites, Ca, Mg and Mn in the case of Cu, and P, in the case of As, played a major role in the distribution of these elements in soil. Element-specific distributions were observed amongst the six identified soil phases including residual pore salts, exchangeable, carbonates (tentative designation), Mn-Al oxide, amorphous Fe oxide, and crystalline Fe oxide. While Cr was strongly bound to non-extractable crystalline Fe oxide in the oxic top soil, Cu and notably, As were associated with readily extractable phases, suggesting that Cu and As, and not Cr, constitute the highest risk to environmental and human health. However, bioavailable Cu did not significantly correlate with CISED identified soil phases, suggesting that sequential extraction schemes such as CISED may not be ideally suited for inferring bioavailability to microorganisms in soil and supports the integration of receptor-specific bioavailability tests into risk assessments as a complement to chemical methods.

This paper evaluated the precision of predictions for chromated copper arsenate preservative retention in wood using X-ray fluorescence and near infrared diffuse reflectance. The quality of the predictions were compared with each other and with retention values obtained experimentally by gravimetric method, atomic absorption and total ash content. Coefficients of determination between the K-Alpha fluorescence intensities and near infrared diffuse reflectance with regard to conventional methods were between 0,909 and 0,986. The results can be considered acceptable for predictive purposes or even good for quality control purposes. In turn, the prediction errors were better than obtained by several studies., Se realizó un análisis comparativo de la precisión de los resultados en la determinación de la retención de óxidos de cobre, cromo y arsénico en madera impregnada con arseniato de cobre cromatado entre fluorescencia de rayos X y espectrometría de reflectancia difusa de infrarrojos cercanos. Los resultados de la calidad de las predicciones fueron comparados entre sí y con valores de retención obtenidos experimentalmente por método gravimétrico, absorción atómica y por cenizas resultantes de su calcinación. Los resultados del coeficiente de determinación del análisis de regresión entre la intensidad de fluorescencia de rayos X de las líneas K-Alpha y entre el espectro de reflectancia difusa de infrarrojos con respecto a la retención medida por métodos convencionales se encontraron en un rango de 0,909 a 0,986. Los resultados obtenidos pueden ser considerados aceptables para fines predictivos o incluso adecuados para propósitos de control de calidad. A su vez, al ser comparados por sus niveles de error de estimación, estos resultados fueron mejores que los obtenidos por otros estudios similares.

This paper evaluated the precision of predictions for chromated copper arsenate preservative retention in wood using X-ray fluorescence and near infrared diffuse reflectance. The quality of the predictions were compared with each other and with retention values obtained experimentally by gravimetric method, atomic absorption and total ash content. Coefficients of determination between the K-Alpha fluorescence intensities and near infrared diffuse reflectance with regard to conventional methods were between 0,909 and 0,986. The results can be considered acceptable for predictive purposes or even good for quality control purposes. In turn, the prediction errors were better than obtained by several studies., Se realizó un análisis comparativo de la precisión de los resultados en la determinación de la retención de óxidos de cobre, cromo y arsénico en madera impregnada con arseniato de cobre cromatado entre fluorescencia de rayos X y espectrometría de reflectancia difusa de infrarrojos cercanos. Los resultados de la calidad de las predicciones fueron comparados entre sí y con valores de retención obtenidos experimentalmente por método gravimétrico, absorción atómica y por cenizas resultantes de su calcinación. Los resultados del coeficiente de determinación del análisis de regresión entre la intensidad de fluorescencia de rayos X de las líneas K-Alpha y entre el espectro de reflectancia difusa de infrarrojos con respecto a la retención medida por métodos convencionales se encontraron en un rango de 0,909 a 0,986. Los resultados obtenidos pueden ser considerados aceptables para fines predictivos o incluso adecuados para propósitos de control de calidad. A su vez, al ser comparados por sus niveles de error de estimación, estos resultados fueron mejores que los obtenidos por otros estudios similares.

This paper evaluated the precision of predictions for chromated copper arsenate preservative retention in wood using X-ray fluorescence and near infrared diffuse reflectance. The quality of the predictions were compared with each other and with retention values obtained experimentally by gravimetric method, atomic absorption and total ash content. Coefficients of determination between the K-Alpha fluorescence intensities and near infrared diffuse reflectance with regard to conventional methods were between 0,909 and 0,986. The results can be considered acceptable for predictive purposes or even good for quality control purposes. In turn, the prediction errors were better than obtained by several studies., Se realizó un análisis comparativo de la precisión de los resultados en la determinación de la retención de óxidos de cobre, cromo y arsénico en madera impregnada con arseniato de cobre cromatado entre fluorescencia de rayos X y espectrometría de reflectancia difusa de infrarrojos cercanos. Los resultados de la calidad de las predicciones fueron comparados entre sí y con valores de retención obtenidos experimentalmente por método gravimétrico, absorción atómica y por cenizas resultantes de su calcinación. Los resultados del coeficiente de determinación del análisis de regresión entre la intensidad de fluorescencia de rayos X de las líneas K-Alpha y entre el espectro de reflectancia difusa de infrarrojos con respecto a la retención medida por métodos convencionales se encontraron en un rango de 0,909 a 0,986. Los resultados obtenidos pueden ser considerados aceptables para fines predictivos o incluso adecuados para propósitos de control de calidad. A su vez, al ser comparados por sus niveles de error de estimación, estos resultados fueron mejores que los obtenidos por otros estudios similares.

This paper evaluated the precision of predictions for chromated copper arsenate preservative retention in wood using X-ray fluorescence and near infrared diffuse reflectance. The quality of the predictions were compared with each other and with retention values obtained experimentally by gravimetric method, atomic absorption and total ash content. Coefficients of determination between the K-Alpha fluorescence intensities and near infrared diffuse reflectance with regard to conventional methods were between 0,909 and 0,986. The results can be considered acceptable for predictive purposes or even good for quality control purposes. In turn, the prediction errors were better than obtained by several studies., Se realizó un análisis comparativo de la precisión de los resultados en la determinación de la retención de óxidos de cobre, cromo y arsénico en madera impregnada con arseniato de cobre cromatado entre fluorescencia de rayos X y espectrometría de reflectancia difusa de infrarrojos cercanos. Los resultados de la calidad de las predicciones fueron comparados entre sí y con valores de retención obtenidos experimentalmente por método gravimétrico, absorción atómica y por cenizas resultantes de su calcinación. Los resultados del coeficiente de determinación del análisis de regresión entre la intensidad de fluorescencia de rayos X de las líneas K-Alpha y entre el espectro de reflectancia difusa de infrarrojos con respecto a la retención medida por métodos convencionales se encontraron en un rango de 0,909 a 0,986. Los resultados obtenidos pueden ser considerados aceptables para fines predictivos o incluso adecuados para propósitos de control de calidad. A su vez, al ser comparados por sus niveles de error de estimación, estos resultados fueron mejores que los obtenidos por otros estudios similares.

The interactions of co-present Cr(VI) and As(V), and the influences of humic acid and bicarbonate in the process of Cr(VI) and As(V) removal by Fe-0 were investigated in a batch setting using simulated groundwater with 5 mM NaCl, 1 mM Na2SO4, and 0.8 mM CaCl2 as background electrolytes at an initial pH value of 7. Cr(VI) and As(V) were observed to be subject to different impacts induced by co-existing As(V) or Cr(VI), humic acid and bicarbonate, originating from their distinct removal mechanisms by Fe-0. Cr(VI) removal is a reduction-dominated process, whereas As(V) removal principally involves adsorption onto iron corrosion products. Experimental results showed that Cr(VI) removal was not affected by the presence of As(V) and humic acid. However, As(V) removal appeared to be inhibited by co-present Cr(VI). When the Cr(VI) concentration was 2, 5, and 10 mg/L, in the absence of humic acid and bicarbonate, As(V) removal rate constants were decreased by 27.9\%, 49.0\%, and 61.2\%, respectively, which probably resulted from competition between Cr(VI) and As(V) for adsorption sites of the iron corrosion products. Furthermore, the presence of humic acid significantly varied As(V) removal kinetics by delaying the formation and aggregation of iron hydroxides due to the formation of soluble Fe-humate complexes and stably dispersed fine iron hydroxides colloids. In the presence of bicarbonate, both Cr(VI) and As(V) removal was increased and the inhibitory effect of Cr(VI) on As(V) removal was suppressed, resulting from the buffering effects and the promoted iron corrosion induced by bicarbonate, and the formation of CaCO3 in solution, which enhanced As(V) adsorption. (C) 2009 Elsevier Ltd. All rights reserved.

The interactions of co-present Cr(VI) and As(V), and the influences of humic acid and bicarbonate in the process of Cr(VI) and As(V) removal by Fe-0 were investigated in a batch setting using simulated groundwater with 5 mM NaCl, 1 mM Na2SO4, and 0.8 mM CaCl2 as background electrolytes at an initial pH value of 7. Cr(VI) and As(V) were observed to be subject to different impacts induced by co-existing As(V) or Cr(VI), humic acid and bicarbonate, originating from their distinct removal mechanisms by Fe-0. Cr(VI) removal is a reduction-dominated process, whereas As(V) removal principally involves adsorption onto iron corrosion products. Experimental results showed that Cr(VI) removal was not affected by the presence of As(V) and humic acid. However, As(V) removal appeared to be inhibited by co-present Cr(VI). When the Cr(VI) concentration was 2, 5, and 10 mg/L, in the absence of humic acid and bicarbonate, As(V) removal rate constants were decreased by 27.9\%, 49.0\%, and 61.2\%, respectively, which probably resulted from competition between Cr(VI) and As(V) for adsorption sites of the iron corrosion products. Furthermore, the presence of humic acid significantly varied As(V) removal kinetics by delaying the formation and aggregation of iron hydroxides due to the formation of soluble Fe-humate complexes and stably dispersed fine iron hydroxides colloids. In the presence of bicarbonate, both Cr(VI) and As(V) removal was increased and the inhibitory effect of Cr(VI) on As(V) removal was suppressed, resulting from the buffering effects and the promoted iron corrosion induced by bicarbonate, and the formation of CaCO3 in solution, which enhanced As(V) adsorption. (C) 2009 Elsevier Ltd. All rights reserved.

The interactions of co-present Cr(VI) and As(V), and the influences of humic acid and bicarbonate in the process of Cr(VI) and As(V) removal by Fe-0 were investigated in a batch setting using simulated groundwater with 5 mM NaCl, 1 mM Na2SO4, and 0.8 mM CaCl2 as background electrolytes at an initial pH value of 7. Cr(VI) and As(V) were observed to be subject to different impacts induced by co-existing As(V) or Cr(VI), humic acid and bicarbonate, originating from their distinct removal mechanisms by Fe-0. Cr(VI) removal is a reduction-dominated process, whereas As(V) removal principally involves adsorption onto iron corrosion products. Experimental results showed that Cr(VI) removal was not affected by the presence of As(V) and humic acid. However, As(V) removal appeared to be inhibited by co-present Cr(VI). When the Cr(VI) concentration was 2, 5, and 10 mg/L, in the absence of humic acid and bicarbonate, As(V) removal rate constants were decreased by 27.9\%, 49.0\%, and 61.2\%, respectively, which probably resulted from competition between Cr(VI) and As(V) for adsorption sites of the iron corrosion products. Furthermore, the presence of humic acid significantly varied As(V) removal kinetics by delaying the formation and aggregation of iron hydroxides due to the formation of soluble Fe-humate complexes and stably dispersed fine iron hydroxides colloids. In the presence of bicarbonate, both Cr(VI) and As(V) removal was increased and the inhibitory effect of Cr(VI) on As(V) removal was suppressed, resulting from the buffering effects and the promoted iron corrosion induced by bicarbonate, and the formation of CaCO3 in solution, which enhanced As(V) adsorption. (C) 2009 Elsevier Ltd. All rights reserved.

The aim of this investigation was to determine the occurrence of As, Cu, Cr and Zn in the soil at an abandoned wood preservation unit and to examine some possible extractants for the contaminants in the soil. The mean As content of the contaminated surface soils (0-10 cm) was 186 mg kg(-1), where as the mean concentrations of Cu, Cr and Zn in soils from the contaminated area were 26, 29 and 91 mg kg(-1), respectively. The elevated As content in the mineral soils is related to adsorption of inorganic As phases in the fine grained fractions, which are characterised by large surface area and high positive surface charge under the current acidic conditions. Cu and Cr were found to be rather mobile, which is reflected in their lower abundance in soils and significant accumulation in sediments in the drainage leaving the area. The fine fraction of the soil (<0.125 mm) has an average metal content increased by nearly 34% as compared to the <2-mm fraction conventionally used for the analysis and assessment of soil contamination. The <2-mm fraction constitutes approximately 65% of the total weight while the fine fraction (< 0.125 mm) constitutes approximately 10%. These facts, taken together, are essential for the choice of remediation measures. Oxalate solutions have been tested as extractants for soil remediation. Dark acid oxalate extraction dissolves the amorphous Al- and Fe-oxides and hydroxides and mobilises the adsorbed inorganic As species. Oxalate also acts as a ligand for the cationic heavy metals, releasing them from exchangeable sites. With a three-step sequential leaching, up to 98-99% of the metals could be removed. At lower concentrations and higher pH, the leaching decreased to approximately 70%., QC 20100525

Timber bridge components are treated with chromated copper arsenate type C (CCA), pentachlorophenol or creosote to preserve the life of the structure from a few years to many decades, resulting in reduced transportation infrastructure costs and increased public safety. However, small amounts of the preservative are lost over time. This report describes the concentration of wood preservativeslost to adjacent environments and the biological responses to these preservatives as environmental contaminents. Six bridges in several states were examined for risk assessment.