The Experts below are selected from a list of 240 Experts worldwide ranked by ideXlab platform
James F. Barker - One of the best experts on this subject based on the ideXlab platform.
-
oxidation kinetics of polycyclic aromatic hydrocarbons by permanganate
Chemosphere, 2010Co-Authors: Steven P Forsey, Neil R Thomson, James F. BarkerAbstract:Abstract The reactivity of permanganate towards polycyclic aromatics hydrocarbons (PAHs) is well known but little kinetic information is available. This study investigated the oxidation kinetics of a selected group of coal Tar Creosote compounds and alkylbenzenes in water using permanganate, and the correlation between compound reactivity and physical/chemical properties. The oxidation of naphthalene, phenanthrene, chrysene, 1-methylnaphthalene, 2-methylnaphthalene, acenaphthene, fluorene, carbazole isopropylbenzene, ethylbenzene and methylbenzene closely followed pseudo first-order reaction kinetics. The oxidation of pyrene was initially very rapid and did not follow pseudo first-order kinetics at early times. Fluoranthene was only partially oxidized and the oxidation of anthracene was too fast to be captured. Biphenyl, dibenzofuran, benzene and tert -butylbenzene were non-reactive under the study conditions. The oxidation rate was shown to increase with increasing number of polycyclic rings because less energy is required to overcome the aromatic character of a polycyclic ring than is required for benzene. Thus the rate of oxidation increased in the series naphthalene
-
Natural attenuation of a plume from an emplaced coal Tar Creosote source over 14 years
Journal of Contaminant Hydrology, 2008Co-Authors: M Fraser, James F. Barker, Barbara J. Butler, F Blaine, S Joseph, C CookeAbstract:Abstract An emplaced source of coal Tar Creosote within the sandy Borden research aquifer has documented the long-term (5140 days) natural attenuation for this complex mixture. Plumes of dissolved chemicals were produced by the essentially horizontal groundwater flowing at about 9 cm/day. Eleven chemicals have been extensively sampled seven times using a monitoring network of ∼ 280, 14-point multilevel samplers. A model of source dissolution using Raoult's Law adequately predicted the dissolution of 9 of 11 compounds. Mass transformation has limited the extent of the plumes as groundwater has flowed more than 500 m, yet the plumes are no longer than 50 m. Phenol and xylenes have been removed and naphthalene has attenuated from its maximum extent on day 1357. Some compound plumes have reached an apparent steady state and the plumes of other compounds (dibenzofuran and phenanthrene) are expected to continue to expand due to an increasing mass flux and limited degradation potential. Biotransformation is the major process controlling natural attenuation at the site. The greatest organic mass lost is associated with the high solubility compounds. However, the majority of the mass loss for most compounds has occurred in the source zone. Oxygen is the main electron acceptor, yet the amount of organics lost cannot be accounted for by aerobic mineralization or partial mineralization alone. The complex evolution of these plumes has been well documented but understanding the controlling biotransformation processes is still elusive. This study has shown that anticipating bioattenuation patterns should only be considered at the broadest scale. Generally, the greatest mass loss is associated with those compounds that have a high solubility and low partitioning coefficients.
-
Migration and natural fate of a coal Tar Creosote plume: 1. Overview and plume development
Journal of Contaminant Hydrology, 1999Co-Authors: Mark W.g. King, James F. BarkerAbstract:A volume of sand containing coal Tar Creosote was emplaced below the water table at CFB Borden to investigate natural attenuation processes for complex biodegradable mixtures. Coal Tar Creosote is a mixture of more than 200 polycyclic aromatic hydrocarbons, heterocyclic compounds and phenolic compounds. A representative group of seven compounds was selected for detailed study: phenol, m-xylene, naphthalene, phenanthrene, 1-methylnaphthalene, dibenzofuran and carbazole. Movement of groundwater through the source led to the development of a dissolved organic plume, which was studied over a 4-year period. Qualitative plume observations and mass balance calculations indicated two key conclusions: (1) compounds from the same source can display distinctly different patterns of plume development and (2) mass transformation was a major influence on plume behaviour for all observed compounds.
-
Migration and natural fate of a coal Tar Creosote plume. 2. Mass balance and biodegradation indicators
Journal of Contaminant Hydrology, 1999Co-Authors: Mark W.g. King, James F. Barker, John F. Devlin, Barbara J. ButlerAbstract:Abstract A source of coal Tar Creosote was emplaced below the water table at CFB Borden to investigate natural attenuation processes for complex biodegradable mixtures. A mass balance indicated that ongoing transformation occurred for seven study compounds. Phenol migrated as a discrete slug plume and almost completely disappeared after 2 years, after being completely leached from the source early in the study. The m -xylene plume migrated outward to a maximum distance at approximately 2 years, and then receded back towards the source as the rate of mass flux out of the source decreased to below the overall rate of plume transformation. Carbazole showed similar behaviour, although the reversal in plume development occurred more slowly. The dibenzofuran plume remained relatively constant in extent and mass over the last 2 years of monitoring, despite constant source input over this period, providing evidence that the dibenzofuran plume was at steady state. Meanwhile, the naphthalene and 1-methylnaphthalene plumes continued to advance and increase in mass over the observation period, although at a decreasing rate. The phenanthrene plume was also subject to transformation, although measurement of the rate was less conclusive due to the higher proportion of sorbed mass for this compound. Three lines of evidence are presented to evaluate whether the observed plume mass loss was due to microbial biodegradation. Measurement of redox-sensitive parameters in the vicinity of the plume showed the types of changes that would be expected to occur due to plume biodegradation: dissolved oxygen and SO 4 2− decreased in groundwater within the plume while significant increases were noted for Fe 2+ , Mn 2+ and methane. Further evidence that plume mass loss was microbially-mediated was provided by the accumulation of aromatic acids within the plume. Measurements of phospholipid fatty acids (PLFA) in aquifer material indicated that microbial biomass and turnover rate were greater within the plume than outside: also consistent with biodegradation. Study results highlight the potential for utilizing natural attenuation as a site cleanup approach for dissolved phase plumes from complex organic mixture like coal Tar Creosote.
-
2. Mass balance and biodegradation indicators
1999Co-Authors: Mark W.g. King, James F. Barker, John F. Devlin, Barbara J. ButlerAbstract:A source of coal Tar Creosote was emplaced below the water table at CFB Borden to investigate natural attenuation processes for complex biodegradable mixtures. A mass balance indicated that ongoing transformation occurred for seven study compounds. Phenol migrated as a discrete slug plume and almost completely disappeared after 2 years, after being completely leached from the source early in the study. The m-xylene plume migrated outward to a maximum distance at approximately 2 years, and then receded back towards the source as the rate of mass flux out of the source decreased to below the overall rate of plume transformation. Carbazole showed similar behaviour, although the reversal in plume development occurred more slowly. The dibenzofuran plume remained relatively constant in extent and mass over the last 2 years of monitoring, despite constant source input over this period, providing evidence that the dibenzofuran plume was at steady state. Meanwhile, the naphthalene and 1-methylnaphthalene plumes continued to advance and increase in mass over the observation period, although at a decreasing rate. The phenanthrene plume was also subject to transformation, although measurement of the rate was less conclusive due to the higher proportion of sorbed mass for this compound. Three lines of evidence are presented to evaluate whether the observed plume mass loss was due to microbial biodegradation. Measurement of redox-sensitive parameters in the vicinity of the plume showed the types of changes that would be expected to occur due to plume biodegradation: dissolved oxygen and SO 2y decreased in groundwater within the plume while significant increases were noted for Fe 2q , 4
Peter Grathwohl - One of the best experts on this subject based on the ideXlab platform.
-
time scales of organic contaminant dissolution from complex source zones coal Tar pools vs blobs
Journal of Contaminant Hydrology, 2002Co-Authors: C Eberhardt, Peter GrathwohlAbstract:Abstract Groundwater contamination due to complex organic mixtures such as coal Tar, Creosote and fuels is a widespread problem in industrialized regions. Although most compounds in these mixtures are biodegradable, the contaminant sources are very persistent for many decades after the contamination occurred (e.g., more than 100 years ago at gasworks sites). This limited bioavailability is due to slow dissolution processes. This study presents results from a large scale tank experiment (8 m long) on the long-term (354 days) dissolution kinetics of BTEX and PAHs from a 2.5 m long coal Tar pool and 0.5 m long (smear) zone containing coal Tar blobs distributed in a coarse sand. The results indicate (1) that Raoult's law holds for estimation of the saturation aqueous concentrations of the coal Tar constituents, (2) that for the dissolution of smear zones longer than approximately 0.1 m and with more than 3–5% residual saturation, the local equilibrium assumption is valid and (3) that although very small (
-
Time scales of organic contaminant dissolution from complex source zones: coal Tar pools vs. blobs.
Journal of contaminant hydrology, 2002Co-Authors: C Eberhardt, Peter GrathwohlAbstract:Groundwater contamination due to complex organic mixtures such as coal Tar, Creosote and fuels is a widespread problem in industrialized regions. Although most compounds in these mixtures are biodegradable, the contaminant sources are very persistent for many decades after the contamination occurred (e.g., more than 100 years ago at gasworks sites). This limited bioavailability is due to slow dissolution processes. This study presents results from a large scale tank experiment (8 m long) on the long-term (354 days) dissolution kinetics of BTEX and PAHs from a 2.5 m long coal Tar pool and 0.5 m long (smear) zone containing coal Tar blobs distributed in a coarse sand. The results inidicate (1) that Raoult's law holds for estimation of the saturation aqueous concentrations of the coal Tar constituents, (2) that for the dissolution of smear zones longer than approximately 0.1 m and with more than 3-5% residual saturation, the local equilibrium assumption is valid and (3) that although very small (< 0.1 mm), the transverse vertical dispersivity dominates the pool dissolution processes. Typical time scales for removal of the pollutants from the blob zone and the pool are in the order of a few weeks to more than 10,000 years, respectively.
Paes, Juarez Benigno - One of the best experts on this subject based on the ideXlab platform.
-
Corrosividade causada por soluções produzidas com creosoto vegetal
Revista Árvore, 2002Co-Authors: Paes, Juarez Benigno, Vital, Benedito Rocha, Lucia, Ricardo Marius DellaAbstract:Esta pesquisa teve como objetivo avaliar a corrosividade de soluções preservativas preparadas com creosoto vegetal. Por destilação do alcatrão vegetal, obteve-se o creosoto vegetal bruto, recuperado à temperatura de 110–255 ºC. Uma fração deste destilado foi lavada com solução a 9% de bicarbonato de sódio, obtendo-se o creosoto vegetal purificado. Ambas as frações foram enriquecidas com 3% de naftenato de cobre; 3% de naftenato de zinco; 3% de naftenato de cobalto; 2% de TBTO; 2% de tribromofenato de tributil-estanho; 2% de pentaclorofenol; ou 0,4% de trióxido de arsênico. Foram preparadas 16 soluções preservativas, sendo 14 enriquecidas, além do creosoto vegetal bruto e do creosoto vegetal purificado. Placas de aço SAE 1006 foram expostas por 6 horas às temperaturas de 25, 45 e 100 ºC, à ação corrosiva dessas soluções. A corrosividade das soluções de creosoto vegetal foi comparada à corrosividade causada pelo creosoto mineral. As soluções preparadas com creosoto vegetal purificado foram menos corrosivas que suas similares preparadas com creosoto vegetal bruto, sem, no entanto, atingir a baixa corrosividade do creosoto mineral.The objective of this research was to evaluate the corrosiveness of preservative solutions prepared with wood Tar Creosote. By distilling of wood Tar, crude wood Tar Creosote was recovered at a temperature of 100–255 ºC. A fraction of this product was washed with a solution of sodium bicarbonate at 9%, resulting in purified wood Tar Creosote. Both fractions were enriched with 3% copper naphtenate, 3% zinc naphtenate, 3% cobalt naphtenate, 2% TBTO, 2% tributhyl-tin tribromophenate, 2% pentachlorophenol, or with 0.4% arsenic trioxide. A total of 16 preservative solutions were prepared of which 14 were enriched, besides the crude wood Tar Creosote and the purified wood Tar Creosote. SAE 1006 steel plates were exposed for 6 hours at temperatures of 25, 45 and 100 ºC, to the corrosive action of those solutions. The corrosiveness of wood Tar Creosote solutions was compared with that caused by coal Tar Creosote. The solutions with purified wood Tar Creosote were less corrosive than similar solutions prepared with crude wood Tar Creosote, although being more corrosive than the coal Tar Creosote
-
Corrosion caused by solutions produced with wood Tar Creosote
Sociedade de Investigações Florestais, 2002Co-Authors: Paes, Juarez Benigno, Vital, Benedito Rocha, Della Lucia, Ricardo Marius, Della Lucia, Terezinha Maria CastroAbstract:Esta pesquisa teve como objetivo avaliar a corrosividade de soluções preservativas preparadas com creosoto vegetal. Por destilação do alcatrão vegetal, obteve-se o creosoto vegetal bruto, recuperado à temperatura de 110-255 ºC. Uma fração deste destilado foi lavada com solução a 9% de bicarbonato de sódio, obtendo-se o creosoto vegetal purificado. Ambas as frações foram enriquecidas com 3% de naftenato de cobre; 3% de naftenato de zinco; 3% de naftenato de cobalto; 2% de TBTO; 2% de tribromofenato de tributil-estanho; 2% de pentaclorofenol; ou 0,4% de trióxido de arsênico. Foram preparadas 16 soluções preservativas, sendo 14 enriquecidas, além do creosoto vegetal bruto e do creosoto vegetal purificado. Placas de aço SAE 1006 foram expostas por 6 horas às temperaturas de 25, 45 e 100 ºC, à ação corrosiva dessas soluções. A corrosividade das soluções de creosoto vegetal foi comparada à corrosividade causada pelo creosoto mineral. As soluções preparadas com creosoto vegetal purificado foram menos corrosivas que suas similares preparadas com creosoto vegetal bruto, sem, no entanto, atingir a baixa corrosividade do creosoto mineral.The objective of this research was to evaluate the corrosiveness of preservative solutions prepared with wood Tar Creosote. By distilling of wood Tar, crude wood Tar Creosote was recovered at a temperature of 100-255 ºC. A fraction of this product was washed with a solution of sodium bicarbonate at 9%, resulting in purified wood Tar Creosote. Both fractions were enriched with 3% copper naphtenate, 3% zinc naphtenate, 3% cobalt naphtenate, 2% TBTO, 2% tributhyl-tin tribromophenate, 2% pentachlorophenol, or with 0.4% arsenic trioxide. A total of 16 preservative solutions were prepared of which 14 were enriched, besides the crude wood Tar Creosote and the purified wood Tar Creosote. SAE 1006 steel plates were exposed for 6 hours at temperatures of 25, 45 and 100 ºC, to the corrosive action of those solutions. The corrosiveness of wood Tar Creosote solutions was compared with that caused by coal Tar Creosote. The solutions with purified wood Tar Creosote were less corrosive than similar solutions prepared with crude wood Tar Creosote, although being more corrosive than the coal Tar Creosote
-
Effects of the purification and enrichment of wood Tar Creosote on preservation of Eucalyptus grandis wood, after 48 months of field testing
Sociedade de Investigações Florestais, 2002Co-Authors: Paes, Juarez Benigno, Vital, Benedito Rocha, Della Lucia, Ricardo Marius, Della Lucia, Terezinha Maria CastroAbstract:O objetivo deste trabalho foi avaliar a eficiência da purificação e do enriquecimento do creosoto vegetal contra xilófagos, após 48 meses de instalação do ensaio de campo. Por destilação do alcatrão vegetal, obteve-se o creosoto vegetal bruto (creosoto 1), recuperado à temperatura de 110-255 °C. Uma fração dos destilados foi lavada com solução a 9% de bicarbonato de sódio, para obter o creosoto vegetal purificado (creosoto 2). Os creosotos 1 e 2 foram enriquecidos com 3% de naftenato de cobre; 3% de naftenato de zinco; 3% de naftenato de cobalto; 2% de TBTO; 2% de tribromofenato de tributil-estanho; 2% de pentaclorofenol; ou 0,4% de trióxido de arsênico. Estacas obtidas do alburno de Eucalyptus grandis foram tratadas pelo processo de célula cheia. A eficiência das soluções de creosoto vegetal foi comparada com a do creosoto mineral. O ensaio foi instalado em três localidades (Viçosa, Ponte Nova e Leopoldina). Os resultados indicam que o creosoto 2 + pentaclorofenol foi superior aos creosotos 1 e 2 + TBTO, aos creosotos 1 e 2 + naftenato de zinco e ao creosoto 1 puro, sendo semelhante ao creosoto mineral. O creosoto 2 foi superior ao creosoto 1 apenas para a localidade de Leopoldina. De modo geral, a vida média da madeira não-tratada ficou entre 12 e 24 meses, a da madeira tratada com o creosoto 1 + TBTO entre 24 e 37 meses e a da tratada com o creosoto 1 + naftenato de zinco entre 37 e 48 meses e a com o creosoto 1 + naftenato de cobalto, creosoto 2 puro e creosoto 2 + naftenato de zinco ou TBTO foi de 48 meses. No atual estágio da pesquisa, não é possível estimar a vida média da madeira tratada com as demais soluções preservativas testadas, pois ainda não atingiram os 60% das estacas quebradas.The objective of this work was to evaluate the efficiency of purifying and enriching wood Tar Creosote against wood decay after 48 months in field testing. By distillation of wood Tar, the crude wood Tar (Creosote 1) was recovered at a temperature of 110-255 °C. A fraction of the distilled was washed with a solution of sodium bicarbonate at 9%, resulting in purified wood Tar Creosote (Creosote 2). Creosotes 1 and 2 were enriched with 3% copper naphtenate; 3% zinc naphtenate; 3% of cobalt naphtenate; 2% TBTO; 2% tributil-tin tribromophenate; 2% pentachlorophenol; or 0.4% arsenic trioxide. Stakes of Eucalyptus grandis sapwood were treated by following the full cell process. The efficiency of wood Tar Creosote solutions was compared with that of coal Tar Creosote. The essay was established in three locations (Viçosa, Ponte Nova and Leopoldina -Minas Gerais, Brazil). The results showed that Creosote 2 + pentaclorofenol was superior to Creosotes 1 and 2 + TBTO, to Creosotes 1 and 2 + zinc naftenato and to pure Creosote 1, being similar to coal Tar Creosote. Creosote 2 was superior to Creosote 1, only in Leopoldina. In general, the average life of untreated wood was between 12 and 24 months. The average life of wood treated with Creosote 1 + TBTO was between 24 and 37 months, while that ofwood treated with Creosote 1 + zinc naftenato, between 37 and 48 months and that of wood treated with Creosote 1 + cobalt naftenato, pure Creosote 2, Creosote 2 + zinc naftenato or + TBTO was 48 months. At this stage of research it is not possible to estimate the treated wood average life, as compared with the other tested preservative solutions, it since 60% of the stakes did not break
-
Corrosão de parafusos fixados à madeira tratada com soluções de creosoto vegetal
Revista Árvore, 2002Co-Authors: Paes, Juarez Benigno, Vital, Benedito Rocha, Lucia, Ricardo Marius DellaAbstract:O objetivo desta pesquisa foi avaliar a corrosão de parafusos auto-rosqueáveis fixados à madeira tratada com soluções preservativas preparadas com creosoto vegetal, em condições de campo. Obteve-se o creosoto vegetal bruto por meio da destilação à temperatura de 110 – 255ºC do alcatrão vegetal. Uma fração dos destilados foi lavada com solução a 9% de bicarbonato de sódio, obtendo-se o creosoto vegetal purificado. Ambas as frações foram enriquecidas com 3% de naftenato de cobre; 3% de naftenato de zinco; 3% naftenato de cobalto; 2% de TBTO; 2% de tribromofenato de tubutil-estanho; 2% de pentaclorofenol; ou 0,4% de trióxido de arsênico. Foram preparadas 16 soluções, sendo 14 enriquecidas, além do creosoto vegetal bruto e do creosoto vegetal purificado. Estacas confeccionadas com madeira de alburno de Eucalyptus grandis foram tratadas pelo processo de célula- cheia (processo Bethell). Após o tratamento, parafusos auto-rosquéaveis de ferro zincado foram fixados às estacas. O ensaio foi instalado em três localidades da Zona da Mata de Minas Gerais (Viçosa, Ponte Nova e Leopoldina). A corrosividade das soluções de creosoto vegetal foi comparada à causada pelo creosoto mineral. As soluções preparadas com creosoto vegetal purificado foram menos corrosivas que suas similares preparadas com creosoto vegetal bruto, assemelhando-se ao creosoto mineral.The objective of this research was to evaluate the corrosion of screws fixed into wood treated with preservative solutions of wood Tar Creosote. The crude wood Tar Creosote was obtained through distillation of wood Tar at 110 - 255ºC. A fraction of this product was washed with a solution of sodium bicarbonate at 9%, resulting in purified wood Tar Creosote. Both fractions were enriched with 3% of copper naphtenate, 3% of zinc naphtenate, 3% of cobalt naphtenate, 2% of TBTO, 2% of tributhyl-tin tribromophenate, 2% of pentachlorophenol, or with 0.4% of arsenic trioxide. A total of 16 preservative solutions were prepared, of which 14 were enriched, besides the crude wood Tar Creosote and the purified wood Tar Creosote. Stakes made of Eucalyptus grandis sapwood were treated following the full-cell process (Bethell's process). After the stakes treatment, screws of iron covered with zinc were fixed into the wood stakes. The assay was carried out in three locations (Viçosa, Ponte Nova and Leopoldina - in Zona da Mata, Minas Gerais, Brazil). The corrosiveness of solutions of wood Tar Creosote was compared with the one caused by coal Tar Creosote. The solutions with purified wood Tar Creosote were less corrosive than those prepared with crude wood Tar Creosote, being similar to the coal Tar Creosote
-
Corrosion of screws fixed into wood treated with wood Tar Creosote solutions
Sociedade de Investigações Florestais, 2002Co-Authors: Paes, Juarez Benigno, Della Lucia, Ricardo Marius, Benedito Rocha Vital, Della Lucia, Terezinha Maria CastroAbstract:O objetivo desta pesquisa foi avaliar a corrosão de parafusos auto-rosqueáveis fixados à madeira tratada com soluções preservativas preparadas com creosoto vegetal, em condições de campo. Obteve-se o creosoto vegetal bruto por meio da destilação à temperatura de 110 - 255ºC do alcatrão vegetal. Uma fração dos destilados foi lavada com solução a 9% de bicarbonato de sódio, obtendo-se o creosoto vegetal purificado. Ambas as frações foram enriquecidas com 3% de naftenato de cobre; 3% de naftenato de zinco; 3% naftenato de cobalto; 2% de TBTO; 2% de tribromofenato de tubutil-estanho; 2% de pentaclorofenol; ou 0,4% de trióxido de arsênico. Foram preparadas 16 soluções, sendo 14 enriquecidas, além do creosoto vegetal bruto e do creosoto vegetal purificado. Estacas confeccionadas com madeira de alburno de Eucalyptus grandis foram tratadas pelo processo de célula- cheia (processo Bethell). Após o tratamento, parafusos auto-rosquéaveis de ferro zincado foram fixados às estacas. O ensaio foi instalado em três localidades da Zona da Mata de Minas Gerais (Viçosa, Ponte Nova e Leopoldina). A corrosividade das soluções de creosoto vegetal foi comparada à causada pelo creosoto mineral. As soluções preparadas com creosoto vegetal purificado foram menos corrosivas que suas similares preparadas com creosoto vegetal bruto, assemelhando-se ao creosoto mineral.The objective of this research was to evaluate the corrosion of screws fixed into wood treated with preservative solutions of wood Tar Creosote. The crude wood Tar Creosote was obtained through distillation of wood Tar at 110 - 255ºC. A fraction of this product was washed with a solution of sodium bicarbonate at 9%, resulting in purified wood Tar Creosote. Both fractions were enriched with 3% of copper naphtenate, 3% of zinc naphtenate, 3% of cobalt naphtenate, 2% of TBTO, 2% of tributhyl-tin tribromophenate, 2% of pentachlorophenol, or with 0.4% of arsenic trioxide. A total of 16 preservative solutions were prepared, of which 14 were enriched, besides the crude wood Tar Creosote and the purified wood Tar Creosote. Stakes made of Eucalyptus grandis sapwood were treated following the full-cell process (Bethell's process). After the stakes treatment, screws of iron covered with zinc were fixed into the wood stakes. The assay was carried out in three locations (Viçosa, Ponte Nova and Leopoldina - in Zona da Mata, Minas Gerais, Brazil). The corrosiveness of solutions of wood Tar Creosote was compared with the one caused by coal Tar Creosote. The solutions with purified wood Tar Creosote were less corrosive than those prepared with crude wood Tar Creosote, being similar to the coal Tar Creosote
Della Lucia, Terezinha Maria Castro - One of the best experts on this subject based on the ideXlab platform.
-
Corrosion caused by solutions produced with wood Tar Creosote
Sociedade de Investigações Florestais, 2002Co-Authors: Paes, Juarez Benigno, Vital, Benedito Rocha, Della Lucia, Ricardo Marius, Della Lucia, Terezinha Maria CastroAbstract:Esta pesquisa teve como objetivo avaliar a corrosividade de soluções preservativas preparadas com creosoto vegetal. Por destilação do alcatrão vegetal, obteve-se o creosoto vegetal bruto, recuperado à temperatura de 110-255 ºC. Uma fração deste destilado foi lavada com solução a 9% de bicarbonato de sódio, obtendo-se o creosoto vegetal purificado. Ambas as frações foram enriquecidas com 3% de naftenato de cobre; 3% de naftenato de zinco; 3% de naftenato de cobalto; 2% de TBTO; 2% de tribromofenato de tributil-estanho; 2% de pentaclorofenol; ou 0,4% de trióxido de arsênico. Foram preparadas 16 soluções preservativas, sendo 14 enriquecidas, além do creosoto vegetal bruto e do creosoto vegetal purificado. Placas de aço SAE 1006 foram expostas por 6 horas às temperaturas de 25, 45 e 100 ºC, à ação corrosiva dessas soluções. A corrosividade das soluções de creosoto vegetal foi comparada à corrosividade causada pelo creosoto mineral. As soluções preparadas com creosoto vegetal purificado foram menos corrosivas que suas similares preparadas com creosoto vegetal bruto, sem, no entanto, atingir a baixa corrosividade do creosoto mineral.The objective of this research was to evaluate the corrosiveness of preservative solutions prepared with wood Tar Creosote. By distilling of wood Tar, crude wood Tar Creosote was recovered at a temperature of 100-255 ºC. A fraction of this product was washed with a solution of sodium bicarbonate at 9%, resulting in purified wood Tar Creosote. Both fractions were enriched with 3% copper naphtenate, 3% zinc naphtenate, 3% cobalt naphtenate, 2% TBTO, 2% tributhyl-tin tribromophenate, 2% pentachlorophenol, or with 0.4% arsenic trioxide. A total of 16 preservative solutions were prepared of which 14 were enriched, besides the crude wood Tar Creosote and the purified wood Tar Creosote. SAE 1006 steel plates were exposed for 6 hours at temperatures of 25, 45 and 100 ºC, to the corrosive action of those solutions. The corrosiveness of wood Tar Creosote solutions was compared with that caused by coal Tar Creosote. The solutions with purified wood Tar Creosote were less corrosive than similar solutions prepared with crude wood Tar Creosote, although being more corrosive than the coal Tar Creosote
-
Effects of the purification and enrichment of wood Tar Creosote on preservation of Eucalyptus grandis wood, after 48 months of field testing
Sociedade de Investigações Florestais, 2002Co-Authors: Paes, Juarez Benigno, Vital, Benedito Rocha, Della Lucia, Ricardo Marius, Della Lucia, Terezinha Maria CastroAbstract:O objetivo deste trabalho foi avaliar a eficiência da purificação e do enriquecimento do creosoto vegetal contra xilófagos, após 48 meses de instalação do ensaio de campo. Por destilação do alcatrão vegetal, obteve-se o creosoto vegetal bruto (creosoto 1), recuperado à temperatura de 110-255 °C. Uma fração dos destilados foi lavada com solução a 9% de bicarbonato de sódio, para obter o creosoto vegetal purificado (creosoto 2). Os creosotos 1 e 2 foram enriquecidos com 3% de naftenato de cobre; 3% de naftenato de zinco; 3% de naftenato de cobalto; 2% de TBTO; 2% de tribromofenato de tributil-estanho; 2% de pentaclorofenol; ou 0,4% de trióxido de arsênico. Estacas obtidas do alburno de Eucalyptus grandis foram tratadas pelo processo de célula cheia. A eficiência das soluções de creosoto vegetal foi comparada com a do creosoto mineral. O ensaio foi instalado em três localidades (Viçosa, Ponte Nova e Leopoldina). Os resultados indicam que o creosoto 2 + pentaclorofenol foi superior aos creosotos 1 e 2 + TBTO, aos creosotos 1 e 2 + naftenato de zinco e ao creosoto 1 puro, sendo semelhante ao creosoto mineral. O creosoto 2 foi superior ao creosoto 1 apenas para a localidade de Leopoldina. De modo geral, a vida média da madeira não-tratada ficou entre 12 e 24 meses, a da madeira tratada com o creosoto 1 + TBTO entre 24 e 37 meses e a da tratada com o creosoto 1 + naftenato de zinco entre 37 e 48 meses e a com o creosoto 1 + naftenato de cobalto, creosoto 2 puro e creosoto 2 + naftenato de zinco ou TBTO foi de 48 meses. No atual estágio da pesquisa, não é possível estimar a vida média da madeira tratada com as demais soluções preservativas testadas, pois ainda não atingiram os 60% das estacas quebradas.The objective of this work was to evaluate the efficiency of purifying and enriching wood Tar Creosote against wood decay after 48 months in field testing. By distillation of wood Tar, the crude wood Tar (Creosote 1) was recovered at a temperature of 110-255 °C. A fraction of the distilled was washed with a solution of sodium bicarbonate at 9%, resulting in purified wood Tar Creosote (Creosote 2). Creosotes 1 and 2 were enriched with 3% copper naphtenate; 3% zinc naphtenate; 3% of cobalt naphtenate; 2% TBTO; 2% tributil-tin tribromophenate; 2% pentachlorophenol; or 0.4% arsenic trioxide. Stakes of Eucalyptus grandis sapwood were treated by following the full cell process. The efficiency of wood Tar Creosote solutions was compared with that of coal Tar Creosote. The essay was established in three locations (Viçosa, Ponte Nova and Leopoldina -Minas Gerais, Brazil). The results showed that Creosote 2 + pentaclorofenol was superior to Creosotes 1 and 2 + TBTO, to Creosotes 1 and 2 + zinc naftenato and to pure Creosote 1, being similar to coal Tar Creosote. Creosote 2 was superior to Creosote 1, only in Leopoldina. In general, the average life of untreated wood was between 12 and 24 months. The average life of wood treated with Creosote 1 + TBTO was between 24 and 37 months, while that ofwood treated with Creosote 1 + zinc naftenato, between 37 and 48 months and that of wood treated with Creosote 1 + cobalt naftenato, pure Creosote 2, Creosote 2 + zinc naftenato or + TBTO was 48 months. At this stage of research it is not possible to estimate the treated wood average life, as compared with the other tested preservative solutions, it since 60% of the stakes did not break
-
Corrosion of screws fixed into wood treated with wood Tar Creosote solutions
Sociedade de Investigações Florestais, 2002Co-Authors: Paes, Juarez Benigno, Della Lucia, Ricardo Marius, Benedito Rocha Vital, Della Lucia, Terezinha Maria CastroAbstract:O objetivo desta pesquisa foi avaliar a corrosão de parafusos auto-rosqueáveis fixados à madeira tratada com soluções preservativas preparadas com creosoto vegetal, em condições de campo. Obteve-se o creosoto vegetal bruto por meio da destilação à temperatura de 110 - 255ºC do alcatrão vegetal. Uma fração dos destilados foi lavada com solução a 9% de bicarbonato de sódio, obtendo-se o creosoto vegetal purificado. Ambas as frações foram enriquecidas com 3% de naftenato de cobre; 3% de naftenato de zinco; 3% naftenato de cobalto; 2% de TBTO; 2% de tribromofenato de tubutil-estanho; 2% de pentaclorofenol; ou 0,4% de trióxido de arsênico. Foram preparadas 16 soluções, sendo 14 enriquecidas, além do creosoto vegetal bruto e do creosoto vegetal purificado. Estacas confeccionadas com madeira de alburno de Eucalyptus grandis foram tratadas pelo processo de célula- cheia (processo Bethell). Após o tratamento, parafusos auto-rosquéaveis de ferro zincado foram fixados às estacas. O ensaio foi instalado em três localidades da Zona da Mata de Minas Gerais (Viçosa, Ponte Nova e Leopoldina). A corrosividade das soluções de creosoto vegetal foi comparada à causada pelo creosoto mineral. As soluções preparadas com creosoto vegetal purificado foram menos corrosivas que suas similares preparadas com creosoto vegetal bruto, assemelhando-se ao creosoto mineral.The objective of this research was to evaluate the corrosion of screws fixed into wood treated with preservative solutions of wood Tar Creosote. The crude wood Tar Creosote was obtained through distillation of wood Tar at 110 - 255ºC. A fraction of this product was washed with a solution of sodium bicarbonate at 9%, resulting in purified wood Tar Creosote. Both fractions were enriched with 3% of copper naphtenate, 3% of zinc naphtenate, 3% of cobalt naphtenate, 2% of TBTO, 2% of tributhyl-tin tribromophenate, 2% of pentachlorophenol, or with 0.4% of arsenic trioxide. A total of 16 preservative solutions were prepared, of which 14 were enriched, besides the crude wood Tar Creosote and the purified wood Tar Creosote. Stakes made of Eucalyptus grandis sapwood were treated following the full-cell process (Bethell's process). After the stakes treatment, screws of iron covered with zinc were fixed into the wood stakes. The assay was carried out in three locations (Viçosa, Ponte Nova and Leopoldina - in Zona da Mata, Minas Gerais, Brazil). The corrosiveness of solutions of wood Tar Creosote was compared with the one caused by coal Tar Creosote. The solutions with purified wood Tar Creosote were less corrosive than those prepared with crude wood Tar Creosote, being similar to the coal Tar Creosote
C Eberhardt - One of the best experts on this subject based on the ideXlab platform.
-
time scales of organic contaminant dissolution from complex source zones coal Tar pools vs blobs
Journal of Contaminant Hydrology, 2002Co-Authors: C Eberhardt, Peter GrathwohlAbstract:Abstract Groundwater contamination due to complex organic mixtures such as coal Tar, Creosote and fuels is a widespread problem in industrialized regions. Although most compounds in these mixtures are biodegradable, the contaminant sources are very persistent for many decades after the contamination occurred (e.g., more than 100 years ago at gasworks sites). This limited bioavailability is due to slow dissolution processes. This study presents results from a large scale tank experiment (8 m long) on the long-term (354 days) dissolution kinetics of BTEX and PAHs from a 2.5 m long coal Tar pool and 0.5 m long (smear) zone containing coal Tar blobs distributed in a coarse sand. The results indicate (1) that Raoult's law holds for estimation of the saturation aqueous concentrations of the coal Tar constituents, (2) that for the dissolution of smear zones longer than approximately 0.1 m and with more than 3–5% residual saturation, the local equilibrium assumption is valid and (3) that although very small (
-
Time scales of organic contaminant dissolution from complex source zones: coal Tar pools vs. blobs.
Journal of contaminant hydrology, 2002Co-Authors: C Eberhardt, Peter GrathwohlAbstract:Groundwater contamination due to complex organic mixtures such as coal Tar, Creosote and fuels is a widespread problem in industrialized regions. Although most compounds in these mixtures are biodegradable, the contaminant sources are very persistent for many decades after the contamination occurred (e.g., more than 100 years ago at gasworks sites). This limited bioavailability is due to slow dissolution processes. This study presents results from a large scale tank experiment (8 m long) on the long-term (354 days) dissolution kinetics of BTEX and PAHs from a 2.5 m long coal Tar pool and 0.5 m long (smear) zone containing coal Tar blobs distributed in a coarse sand. The results inidicate (1) that Raoult's law holds for estimation of the saturation aqueous concentrations of the coal Tar constituents, (2) that for the dissolution of smear zones longer than approximately 0.1 m and with more than 3-5% residual saturation, the local equilibrium assumption is valid and (3) that although very small (< 0.1 mm), the transverse vertical dispersivity dominates the pool dissolution processes. Typical time scales for removal of the pollutants from the blob zone and the pool are in the order of a few weeks to more than 10,000 years, respectively.
