The Experts below are selected from a list of 3276 Experts worldwide ranked by ideXlab platform
João Henrique Zimnoch Dos Santos - One of the best experts on this subject based on the ideXlab platform.
-
Synthesis of zirconocene-based silica phases and evaluation in lindane and Heptachlor Epoxide adsorption/desorption
Journal of colloid and interface science, 2005Co-Authors: Ana Maria Geller, Fernanda Chiarello Stedile, Maria Do Carmo Ruaro Peralba, Tânia Mara Pizzolato, João Henrique Zimnoch Dos SantosAbstract:Abstract Silica (350 m2 g−1) was chemically modified with Cp2ZrCl2 and (nBuCp)2ZrCl2 by grafting. Hybrid silica bearing surface indene groups was synthesized by the sol–gel method, followed by metallation with ZrCl4⋅2THF. The resulting phases were characterized by Rutherford backscattering spectrometry (RBS), 13C and 29Si magic angle spin nuclear magnetic resonance, X-ray photoelectron spectroscopy, and diffuse reflectance infrared Fourier transform spectroscopy. According to RBS measurements, metal content was 0.2- to 0.3-wt% Zr/SiO2 for the grafted systems and 4.5-wt% Zr/SiO2 for the phase prepared by the sol–gel method. The solid phases were evaluated for the adsorption/preconcentration of lindane and Heptachlor Epoxide from aqueous solution. For comparative reasons, the commercial LC-18 phase was also evaluated. Analyte concentration was monitored by gas chromatography electron capture detection. For the grafted phases, the coordination sphere around the metal center seems not to influence the adsorption/desorption properties of these phases vis-a-vis the studied analytes. In the case of the phases prepared by the sol–gel method, recovery results were comparable to those observed for LC-18. Experiments using ZrO2 and ZrO2/SiO2 phases led to lower recovery results.
-
synthesis of zirconocene based silica phases and evaluation in lindane and Heptachlor Epoxide adsorption desorption
Journal of Colloid and Interface Science, 2005Co-Authors: Ana Maria Geller, Fernanda Chiarello Stedile, Maria Do Carmo Ruaro Peralba, Tânia Mara Pizzolato, João Henrique Zimnoch Dos SantosAbstract:Abstract Silica (350 m2 g−1) was chemically modified with Cp2ZrCl2 and (nBuCp)2ZrCl2 by grafting. Hybrid silica bearing surface indene groups was synthesized by the sol–gel method, followed by metallation with ZrCl4⋅2THF. The resulting phases were characterized by Rutherford backscattering spectrometry (RBS), 13C and 29Si magic angle spin nuclear magnetic resonance, X-ray photoelectron spectroscopy, and diffuse reflectance infrared Fourier transform spectroscopy. According to RBS measurements, metal content was 0.2- to 0.3-wt% Zr/SiO2 for the grafted systems and 4.5-wt% Zr/SiO2 for the phase prepared by the sol–gel method. The solid phases were evaluated for the adsorption/preconcentration of lindane and Heptachlor Epoxide from aqueous solution. For comparative reasons, the commercial LC-18 phase was also evaluated. Analyte concentration was monitored by gas chromatography electron capture detection. For the grafted phases, the coordination sphere around the metal center seems not to influence the adsorption/desorption properties of these phases vis-a-vis the studied analytes. In the case of the phases prepared by the sol–gel method, recovery results were comparable to those observed for LC-18. Experiments using ZrO2 and ZrO2/SiO2 phases led to lower recovery results.
Ryuichiro Kondo - One of the best experts on this subject based on the ideXlab platform.
-
Biodegradation of Heptachlor and Heptachlor Epoxide-contaminated soils by white-rot fungal inocula.
Environmental science and pollution research international, 2014Co-Authors: Adi Setyo Purnomo, Surya Rosa Putra, Kuniyoshi Shimizu, Ryuichiro KondoAbstract:The ability of certain white-rot fungi (WRF) inocula to transform Heptachlor and Heptachlor Epoxide and its application in artificially contaminated soil were investigated. Fungal inoculum of Pleurotus ostreatus eliminated approximately 89 % of Heptachlor after 28 days of incubation, and chlordene was detected as the primary metabolite. The fungal inoculum of Pleurotus ostreatus had the highest ability to degrade Heptachlor Epoxide; approximately 32 % were degraded after 28 days of incubation, and Heptachlor diol was detected as the metabolite product. Because Pleurotus ostreatus transformed Heptachlor into a less toxic metabolite and could also effectively degrade Heptachlor Epoxide, it was then selected to be applied to artificially contaminated soil. The spent mushroom waste (SMW) of Pleurotus ostreatus degraded Heptachlor and Heptachlor Epoxide by approximately 91 and 26 %, respectively, over 28 days. This finding indicated that Pleurotus ostreatus SMW could be used to bioremediate Heptachlor- and Heptachlor Epoxide-contaminated environments.
-
biotransformation of Heptachlor and Heptachlor Epoxide by white rot fungus pleurotus ostreatus
International Biodeterioration & Biodegradation, 2013Co-Authors: Adi Setyo Purnomo, Toshio Mori, Surya Rosa Putra, Ryuichiro KondoAbstract:Abstract The ability of Pleurotus ostreatus to transform Heptachlor as well as Heptachlor Epoxide was investigated. Heptachlor was eliminated completely by this fungus in potato dextrose broth (PDB) and high nitrogen (HN) media during a 14 d incubation period. Heptachlor Epoxide was detected as the main metabolite besides chlordene and 1-hydoxychlordene. Based on identification of the metabolites, transformation of Heptachlor was proposed which was initially metabolized by epoxidation, dechlorination and hydrolysis. This fungus was also capable of degrading Heptachlor Epoxide which is a recalcitrant metabolite of Heptachlor. Approximately 9%, 8% and 31% of Heptachlor Epoxide was eliminated by P. ostreatus in low nitrogen (LN), HN, and PDB media during 14 days of incubation, respectively. After acetylation, the metabolite, 2,3-dihydroxyHeptachlor (Heptachlor diol), was detected in the PDB medium cultures, suggesting the hydrolysis reaction occurred in the Epoxide ring. This indicated that P. ostreatus is a potential source for transformation of Heptachlor as well as Heptachlor Epoxide.
-
Bioconversion of Heptachlor Epoxide by Wood-Decay Fungi and Detection of Metabolites
Advanced Materials Research, 2012Co-Authors: Peng Fei Xiao, Toshio Mori, Ryuichiro KondoAbstract:Although Heptachlor Epoxide is one of the most persistent organic pollutants (POPs) that cause serious environmental problems, there is very limited information of the biodegradation of Heptachlor Epoxide by microorganisms, and no systematic study on the metabolic products and pathway of endrin by microorganisms has been conducted. Wood-decay fungi can degrade a wide spectrum of recalcitrant organopollutants, including polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated biphenyls (PCBs). In this study, 18 wood-decay fungi strains of genus Phlebia were investigated for their ability to degrade Heptachlor Epoxide, and Phlebia acanthocystis, Phlebia brevispora, Phlebia lindtneri and Phlebia aurea removed about 16, 16, 22 and 25% of Heptachlor Epoxide, respectively, after 14 days of incubation. Heptachlor diol and 1-hydroxy-2,3-epoxychlordene were detected in these fungal cultures as metabolites by gas chromatography and mass spectrometry (GC/MS), suggesting that the hydrolysis reaction in the Epoxide ring and substitution of chlorine atom with hydroxyl group in C1 position occur in bioconversion of Heptachlor Epoxide by selected wood-decay fungi, respectively. This is the first report describing the metabolites of Heptachlor Epoxide by microorganisms.
-
metabolism of organochlorine pesticide Heptachlor and its metabolite Heptachlor Epoxide by white rot fungi belonging to genus phlebia
Fems Microbiology Letters, 2011Co-Authors: Peng Fei Xiao, Toshio Mori, Ichiro Kamei, Ryuichiro KondoAbstract:White rot fungi of the genus Phlebia have demonstrated a high capacity to degrade organic pollutants, including polychlorinated dibenzo-p-dioxins and polychlorinated biphenyls. In this study, we evaluated the ability of 18 white rot fungi species of genus Phlebia to degrade Heptachlor and Heptachlor Epoxide, and described the metabolic pathways by selected white rot fungi. Phlebia tremellosa, Phlebia brevispora and Phlebia acanthocystis removed about 71%, 74% and 90% of Heptachlor, respectively, after 14 days of incubation. A large amount of Heptachlor Epoxide and a small amount of 1-hydroxychlordene and 1-hydroxy-2,3-epoxychlordene were detected as metabolic products of Heptachlor from most fungal cultures. The screening of Heptachlor Epoxide-degrading fungi revealed that several fungi are capable of degrading Heptachlor Epoxide, which is a recalcitrant metabolite of Heptachlor. Phlebia acanthocystis, P. brevispora, Phlebia lindtneri and Phlebia aurea removed about 16%, 16%, 22% and 25% of Heptachlor Epoxide, respectively, after 14 days of incubation. Heptachlor diol and 1-hydroxy-2,3-epoxychlordene were produced in these fungal cultures as metabolites, suggesting that the hydrolysis and hydroxylation reaction occur in the Epoxide ring and in position 1 of Heptachlor Epoxide, respectively.
Ana Maria Geller - One of the best experts on this subject based on the ideXlab platform.
-
Synthesis of zirconocene-based silica phases and evaluation in lindane and Heptachlor Epoxide adsorption/desorption
Journal of colloid and interface science, 2005Co-Authors: Ana Maria Geller, Fernanda Chiarello Stedile, Maria Do Carmo Ruaro Peralba, Tânia Mara Pizzolato, João Henrique Zimnoch Dos SantosAbstract:Abstract Silica (350 m2 g−1) was chemically modified with Cp2ZrCl2 and (nBuCp)2ZrCl2 by grafting. Hybrid silica bearing surface indene groups was synthesized by the sol–gel method, followed by metallation with ZrCl4⋅2THF. The resulting phases were characterized by Rutherford backscattering spectrometry (RBS), 13C and 29Si magic angle spin nuclear magnetic resonance, X-ray photoelectron spectroscopy, and diffuse reflectance infrared Fourier transform spectroscopy. According to RBS measurements, metal content was 0.2- to 0.3-wt% Zr/SiO2 for the grafted systems and 4.5-wt% Zr/SiO2 for the phase prepared by the sol–gel method. The solid phases were evaluated for the adsorption/preconcentration of lindane and Heptachlor Epoxide from aqueous solution. For comparative reasons, the commercial LC-18 phase was also evaluated. Analyte concentration was monitored by gas chromatography electron capture detection. For the grafted phases, the coordination sphere around the metal center seems not to influence the adsorption/desorption properties of these phases vis-a-vis the studied analytes. In the case of the phases prepared by the sol–gel method, recovery results were comparable to those observed for LC-18. Experiments using ZrO2 and ZrO2/SiO2 phases led to lower recovery results.
-
synthesis of zirconocene based silica phases and evaluation in lindane and Heptachlor Epoxide adsorption desorption
Journal of Colloid and Interface Science, 2005Co-Authors: Ana Maria Geller, Fernanda Chiarello Stedile, Maria Do Carmo Ruaro Peralba, Tânia Mara Pizzolato, João Henrique Zimnoch Dos SantosAbstract:Abstract Silica (350 m2 g−1) was chemically modified with Cp2ZrCl2 and (nBuCp)2ZrCl2 by grafting. Hybrid silica bearing surface indene groups was synthesized by the sol–gel method, followed by metallation with ZrCl4⋅2THF. The resulting phases were characterized by Rutherford backscattering spectrometry (RBS), 13C and 29Si magic angle spin nuclear magnetic resonance, X-ray photoelectron spectroscopy, and diffuse reflectance infrared Fourier transform spectroscopy. According to RBS measurements, metal content was 0.2- to 0.3-wt% Zr/SiO2 for the grafted systems and 4.5-wt% Zr/SiO2 for the phase prepared by the sol–gel method. The solid phases were evaluated for the adsorption/preconcentration of lindane and Heptachlor Epoxide from aqueous solution. For comparative reasons, the commercial LC-18 phase was also evaluated. Analyte concentration was monitored by gas chromatography electron capture detection. For the grafted phases, the coordination sphere around the metal center seems not to influence the adsorption/desorption properties of these phases vis-a-vis the studied analytes. In the case of the phases prepared by the sol–gel method, recovery results were comparable to those observed for LC-18. Experiments using ZrO2 and ZrO2/SiO2 phases led to lower recovery results.
Philip A Spear - One of the best experts on this subject based on the ideXlab platform.
-
occurrence and distribution of organochlorine pesticides lindane p p ddt and Heptachlor Epoxide in surface water of china
Environment International, 2008Co-Authors: Jin Lu, Huaidong Zhou, Shengbiao Huang, Zijian Wang, Philip A SpearAbstract:Persistent organochlorine pesticides pollutants (OCPs) have been reported to occur at relatively high concentrations in some Chinese waters. In order to map the distribution of organochlorine pesticides in the surface water throughout China, samples were collected from over 600 sites in seven major river basins and three main internal rivers drainage areas during 2003 and 2004. The surface water samples were analyzed for the representative organochlorine pesticides contaminants including lindane (gamma-HCH), p,p '-DDT and Heptachlor Epoxide. In general, the most frequently detected compound was lindane, being detected in 83.9% of samples (mean =31.3 ng/l; range <0.17-860 ng/l), and the highest concentration was present in the Yellow River basin. p,p,p '-DDT was detected in 63.1% of the samples collected (mean=14.6 ng/l; range <0.14-368 ng/l) with the highest concentration present in the Huaihe River basin. Heptachlor Epoxide was detected in only 9.3% of water samples (range <0.11-10 ng/l). Measured concentrations for the three compounds were low and rarely exceed the environment quality standard for surface water of China. Lindane was more frequently detected at much higher concentrations in the rivers of northern China compared with those of southern China. The sites with higher concentration of lindane and p,p '-DDT mainly occurred in the Yellow River and Huaihe River basins, so the results of this investigation indicate that the organochlorine pesticide contamination of Yellow River and Huaihe River basins should be of particular concern relative to the other basins. When compared with other regions of the world, it appears that the Chinese surface water is moderately polluted by lindane and p,p'-DDT. (c) 2008 Elsevier Ltd. All rights reserved.
-
Occurrence and distribution of organochlorine pesticides - lindane, p,p '-DDT, and Heptachlor Epoxide - in surface water of China
Environment international, 2008Co-Authors: Jijun Gao, Huaidong Zhou, Shengbiao Huang, Zijian Wang, Linghua Liu, Xiaoru Liu, Philip A SpearAbstract:Persistent organochlorine pesticides pollutants (OCPs) have been reported to occur at relatively high concentrations in some Chinese waters. In order to map the distribution of organochlorine pesticides in the surface water throughout China, samples were collected from over 600 sites in seven major river basins and three main internal rivers drainage areas during 2003 and 2004. The surface water samples were analyzed for the representative organochlorine pesticides contaminants including lindane (gamma-HCH), p,p '-DDT and Heptachlor Epoxide. In general, the most frequently detected compound was lindane, being detected in 83.9% of samples (mean =31.3 ng/l; range
Fernanda Chiarello Stedile - One of the best experts on this subject based on the ideXlab platform.
-
Synthesis of zirconocene-based silica phases and evaluation in lindane and Heptachlor Epoxide adsorption/desorption
Journal of colloid and interface science, 2005Co-Authors: Ana Maria Geller, Fernanda Chiarello Stedile, Maria Do Carmo Ruaro Peralba, Tânia Mara Pizzolato, João Henrique Zimnoch Dos SantosAbstract:Abstract Silica (350 m2 g−1) was chemically modified with Cp2ZrCl2 and (nBuCp)2ZrCl2 by grafting. Hybrid silica bearing surface indene groups was synthesized by the sol–gel method, followed by metallation with ZrCl4⋅2THF. The resulting phases were characterized by Rutherford backscattering spectrometry (RBS), 13C and 29Si magic angle spin nuclear magnetic resonance, X-ray photoelectron spectroscopy, and diffuse reflectance infrared Fourier transform spectroscopy. According to RBS measurements, metal content was 0.2- to 0.3-wt% Zr/SiO2 for the grafted systems and 4.5-wt% Zr/SiO2 for the phase prepared by the sol–gel method. The solid phases were evaluated for the adsorption/preconcentration of lindane and Heptachlor Epoxide from aqueous solution. For comparative reasons, the commercial LC-18 phase was also evaluated. Analyte concentration was monitored by gas chromatography electron capture detection. For the grafted phases, the coordination sphere around the metal center seems not to influence the adsorption/desorption properties of these phases vis-a-vis the studied analytes. In the case of the phases prepared by the sol–gel method, recovery results were comparable to those observed for LC-18. Experiments using ZrO2 and ZrO2/SiO2 phases led to lower recovery results.
-
synthesis of zirconocene based silica phases and evaluation in lindane and Heptachlor Epoxide adsorption desorption
Journal of Colloid and Interface Science, 2005Co-Authors: Ana Maria Geller, Fernanda Chiarello Stedile, Maria Do Carmo Ruaro Peralba, Tânia Mara Pizzolato, João Henrique Zimnoch Dos SantosAbstract:Abstract Silica (350 m2 g−1) was chemically modified with Cp2ZrCl2 and (nBuCp)2ZrCl2 by grafting. Hybrid silica bearing surface indene groups was synthesized by the sol–gel method, followed by metallation with ZrCl4⋅2THF. The resulting phases were characterized by Rutherford backscattering spectrometry (RBS), 13C and 29Si magic angle spin nuclear magnetic resonance, X-ray photoelectron spectroscopy, and diffuse reflectance infrared Fourier transform spectroscopy. According to RBS measurements, metal content was 0.2- to 0.3-wt% Zr/SiO2 for the grafted systems and 4.5-wt% Zr/SiO2 for the phase prepared by the sol–gel method. The solid phases were evaluated for the adsorption/preconcentration of lindane and Heptachlor Epoxide from aqueous solution. For comparative reasons, the commercial LC-18 phase was also evaluated. Analyte concentration was monitored by gas chromatography electron capture detection. For the grafted phases, the coordination sphere around the metal center seems not to influence the adsorption/desorption properties of these phases vis-a-vis the studied analytes. In the case of the phases prepared by the sol–gel method, recovery results were comparable to those observed for LC-18. Experiments using ZrO2 and ZrO2/SiO2 phases led to lower recovery results.