The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Françoise M. Robert - One of the best experts on this subject based on the ideXlab platform.
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Phytoremediation of petroleum hydrocarbons in tropical Coastal Soils II. microbial response to plant roots and contaminant
Environmental Science and Pollution Research, 2004Co-Authors: Ryan K. Jones, Wenhao H. Sun, Chung-shih Tang, Françoise M. RobertAbstract:Goal, Scope and Background The goal of this study was to understand the interaction between plants and microorganisms during petroleum-hydrocarbon bioremediation in Pacific Islands Coastal Soils. Total bacteria and hydrocarbon-degrading microorganisms population dynamics were examined in the rhizospheres of tropical trees and shrubs, which were evaluated for their phytoremediation potential in a greenhouse experiment. The respective and combined effects of plant roots and diesel contaminant on the microbial populations were determined in relation to diesel fuel depletion. An increase in the size of the hydrocarbon-degrading populations of microbes, elicited by rhizodeposition, is generally regarded as conducive to an enhanced degradation of petroleum hydrocarbon pollutants in vegetated soil. Methods The soil was a Coastal sandy loam (pH 7.8) which was artificially contaminated with 10 g of No. 2 diesel fuel/kg soil or left uncontaminated. The pots were irrigated with fertilizer and 1% NaCl. The enumerations were carried out in the contaminated and uncontaminated rhizospheres of three trees, kiawe (Prosopis pallida) , milo (Thespesia populnea) , and kou (Cordia subcordata) and three shrubs, beach naupaka (Scaevola sericea) , false sandalwood ( Myoporum sandwicense) , and oleander (Nerium oleander ). Unplanted control Soils were included in the experiment. Total bacteria and phenanthrene-degrading bacteria were enumerated on plates. Diesel- and pristane-de-grading microorganisms were enumerated by the most-probable-number technique in tissue-culture plates. Results and Discussion All four types of microorganisms responded to the rhizosphere of the 6 plants in uncontaminated soil and to the diesel contaminant in unplanted soil. In contaminated rhizospheres, no effect of the plant on the hydrocarbon-degrader numbers was visible. Total bacteria responded more to the plant roots than to the contaminant. The phenanthrene-degrading bacteria and pristane-degrading microorganisms were more influenced by the contaminant than by the plants. The diesel-degrading microorganisms were equally stimulated by the plants and the contaminant. The numbers of hydrocarbon degraders were similar in the contaminated rhizospheres of the three effective plants (kiawe, kou, and milo) and in those of the three ineffective shrubs. Conclusion The results suggest the quality of the rhizodeposition is plant-dependent and governs the type of diesel-degrader populations that will be enhanced by a given plant. Recommendations and Outlook In the proposed phytoremedia-tion-benefit model plant roots maintain high levels of hydrocarbon degraders in uncontaminated soil. When the root enters a contaminated zone of soil, those hydrocarbon degraders that prefer the contaminant would switch to the contaminant as a carbon source, effectively removing the hydrocarbons. If the root exudates and the contaminant are equally attractive to the hydrocarbon degraders, the contaminant degradation would be less effective.
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Phytoremediation of petroleum hydrocarbons in tropical Coastal Soils II. microbial response to plant roots and contaminant
Environmental science and pollution research international, 2004Co-Authors: Ryan K. Jones, Wenhao H. Sun, Chung-shih Tang, Françoise M. RobertAbstract:Goal, Scope and Background. The goal of this study was to understand the interaction between plants and microorganisms during petroleum-hydrocarbon bioremediation in Pacific Islands Coastal Soils. Total bacteria and hydrocarbon-degrading microorganisms population dynamics were examined in the rhizospheres of tropical trees and shrubs, which were evaluated for their phytoremediation potential in a greenhouse experiment. The respective and combined effects of plant roots and diesel contaminant on the microbial populations were determined in relation to diesel fuel depletion. An increase in the size of the hydrocarbon-degrading populations of microbes, elicited by rhizodeposition, is generally regarded as conducive to an enhanced degradation of petroleum hydrocarbon polutants in veaetated soil.
Yongming Luo - One of the best experts on this subject based on the ideXlab platform.
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the distribution and morphology of microplastics in Coastal Soils adjacent to the bohai sea and the yellow sea
Geoderma, 2018Co-Authors: Qian Zhou, Zhenfei Dai, Chuancheng Fu, Chen Tu, Yuan Li, Haibo Zhang, Yang Zhou, Yongming LuoAbstract:Abstract Microplastics ( 3000 km of coastline in Shandong province, east China, adjacent to both the Bohai Sea and the Yellow Sea coastlines under different land use management. Microplastics were separated from the soil samples using a continuous flow and floating separation apparatus. The shape type, size, abundance, spatial distribution, polymer composition and surface morphology of the microplastics were identified by a range of advanced microscopic and micro-analytical methods. The analytical results show that seven shape types, namely foams, pellets, fragments, flakes, fibers, films and sponges, were present in the beach Soils. The polymer composition of the microplastics included polyethylene, polypropylene, polystyrene, polyether urethane and a polymer blend of both polyethylene and polypropylene. Approximately 60% of the observed microplastics had a size range
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magnetic characterization of distinct soil layers and its implications for environmental changes in the Coastal Soils from the yellow river delta
Catena, 2018Co-Authors: Haibo Zhang, Yongming LuoAbstract:Abstract The Soils in the Yellow River Delta (YRD) were formed through the deposition of the Yellow River sediments under complicated hydrodynamic conditions, resulting in large variability in soil properties. In this study, environmental magnetic analyses were conducted on four typical soil profiles and one high resolution soil profile with distinct soil layers to examine the soil formation process and to track the environmental changes. The results showed that the red clay layer (RCL) in the YRD soil profiles had unique magnetic properties, which could be clearly separated from the yellow silt layer (YSL) at frequency dependent susceptibility (χfd%) > 6%, susceptibility of anhysteretic remanent magnetization (χARM) > 250 × 10− 8 m3 kg− 1, χARM/magnetic susceptibility (χlf) > 5, χARM/saturated isothermal remanent magnetization (SIRM) > 45 × 10− 5 m A− 1 and SIRM/χlf
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characteristics of residual organochlorine pesticides in Soils under different land use types on a Coastal plain of the yellow river delta
Environmental Geochemistry and Health, 2016Co-Authors: Haibo Zhang, Yongming Luo, Qian Zhou, Xiaobing Chen, Peter ChristieAbstract:The residual levels of organochlorine pesticides (OCPs) were examined in Soils covering five types of land use along a salinity gradient on the Yellow River Delta. The most prominent OCPs were dichlorodiphenyltrichloroethane (∑DDT, arithmetic mean = 5.11 μg kg−1), hexachlorocyclohexane (∑HCH, 1.69 μg kg−1) and ∑endosulfan (10.4 μg kg−1). The spatial variability of OCPs composition shifted from γ-HCH and o,p′-DDT dominated pesticides in Coastal Soils to p,p′-DDE dominated pesticides in inland Soils. In different land-use types, the percentages of β-HCH and p,p′-DDE are characterized by more recalcitrant components in decreasing order of vegetable fields, cereal fields, cotton fields, wetlands and tidal flats with increasing soil salinity. However, the less recalcitrant components, γ-HCH and o,p′-DDT, showed an opposite trend. Endosulfan sulfate predominated in all land-use types. Residual levels of β-HCH were affected by soil organic matter. The correlations between γ-HCH and clay content and between p,p′-DDE, o,p′-DDT and salinity might associate with the influence of sediment cotransport by the Yellow River and the density of anthropogenic activities in Coastal region. Depth distribution of the OCPs in typical soil profiles also implied that local historical usage and sediment transport by the Yellow River both affected the OCPs residual in this region.
Haibo Zhang - One of the best experts on this subject based on the ideXlab platform.
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the distribution and morphology of microplastics in Coastal Soils adjacent to the bohai sea and the yellow sea
Geoderma, 2018Co-Authors: Qian Zhou, Zhenfei Dai, Chuancheng Fu, Chen Tu, Yuan Li, Haibo Zhang, Yang Zhou, Yongming LuoAbstract:Abstract Microplastics ( 3000 km of coastline in Shandong province, east China, adjacent to both the Bohai Sea and the Yellow Sea coastlines under different land use management. Microplastics were separated from the soil samples using a continuous flow and floating separation apparatus. The shape type, size, abundance, spatial distribution, polymer composition and surface morphology of the microplastics were identified by a range of advanced microscopic and micro-analytical methods. The analytical results show that seven shape types, namely foams, pellets, fragments, flakes, fibers, films and sponges, were present in the beach Soils. The polymer composition of the microplastics included polyethylene, polypropylene, polystyrene, polyether urethane and a polymer blend of both polyethylene and polypropylene. Approximately 60% of the observed microplastics had a size range
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magnetic characterization of distinct soil layers and its implications for environmental changes in the Coastal Soils from the yellow river delta
Catena, 2018Co-Authors: Haibo Zhang, Yongming LuoAbstract:Abstract The Soils in the Yellow River Delta (YRD) were formed through the deposition of the Yellow River sediments under complicated hydrodynamic conditions, resulting in large variability in soil properties. In this study, environmental magnetic analyses were conducted on four typical soil profiles and one high resolution soil profile with distinct soil layers to examine the soil formation process and to track the environmental changes. The results showed that the red clay layer (RCL) in the YRD soil profiles had unique magnetic properties, which could be clearly separated from the yellow silt layer (YSL) at frequency dependent susceptibility (χfd%) > 6%, susceptibility of anhysteretic remanent magnetization (χARM) > 250 × 10− 8 m3 kg− 1, χARM/magnetic susceptibility (χlf) > 5, χARM/saturated isothermal remanent magnetization (SIRM) > 45 × 10− 5 m A− 1 and SIRM/χlf
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characteristics of residual organochlorine pesticides in Soils under different land use types on a Coastal plain of the yellow river delta
Environmental Geochemistry and Health, 2016Co-Authors: Haibo Zhang, Yongming Luo, Qian Zhou, Xiaobing Chen, Peter ChristieAbstract:The residual levels of organochlorine pesticides (OCPs) were examined in Soils covering five types of land use along a salinity gradient on the Yellow River Delta. The most prominent OCPs were dichlorodiphenyltrichloroethane (∑DDT, arithmetic mean = 5.11 μg kg−1), hexachlorocyclohexane (∑HCH, 1.69 μg kg−1) and ∑endosulfan (10.4 μg kg−1). The spatial variability of OCPs composition shifted from γ-HCH and o,p′-DDT dominated pesticides in Coastal Soils to p,p′-DDE dominated pesticides in inland Soils. In different land-use types, the percentages of β-HCH and p,p′-DDE are characterized by more recalcitrant components in decreasing order of vegetable fields, cereal fields, cotton fields, wetlands and tidal flats with increasing soil salinity. However, the less recalcitrant components, γ-HCH and o,p′-DDT, showed an opposite trend. Endosulfan sulfate predominated in all land-use types. Residual levels of β-HCH were affected by soil organic matter. The correlations between γ-HCH and clay content and between p,p′-DDE, o,p′-DDT and salinity might associate with the influence of sediment cotransport by the Yellow River and the density of anthropogenic activities in Coastal region. Depth distribution of the OCPs in typical soil profiles also implied that local historical usage and sediment transport by the Yellow River both affected the OCPs residual in this region.
Ryan K. Jones - One of the best experts on this subject based on the ideXlab platform.
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Phytoremediation of petroleum hydrocarbons in tropical Coastal Soils II. microbial response to plant roots and contaminant
Environmental Science and Pollution Research, 2004Co-Authors: Ryan K. Jones, Wenhao H. Sun, Chung-shih Tang, Françoise M. RobertAbstract:Goal, Scope and Background The goal of this study was to understand the interaction between plants and microorganisms during petroleum-hydrocarbon bioremediation in Pacific Islands Coastal Soils. Total bacteria and hydrocarbon-degrading microorganisms population dynamics were examined in the rhizospheres of tropical trees and shrubs, which were evaluated for their phytoremediation potential in a greenhouse experiment. The respective and combined effects of plant roots and diesel contaminant on the microbial populations were determined in relation to diesel fuel depletion. An increase in the size of the hydrocarbon-degrading populations of microbes, elicited by rhizodeposition, is generally regarded as conducive to an enhanced degradation of petroleum hydrocarbon pollutants in vegetated soil. Methods The soil was a Coastal sandy loam (pH 7.8) which was artificially contaminated with 10 g of No. 2 diesel fuel/kg soil or left uncontaminated. The pots were irrigated with fertilizer and 1% NaCl. The enumerations were carried out in the contaminated and uncontaminated rhizospheres of three trees, kiawe (Prosopis pallida) , milo (Thespesia populnea) , and kou (Cordia subcordata) and three shrubs, beach naupaka (Scaevola sericea) , false sandalwood ( Myoporum sandwicense) , and oleander (Nerium oleander ). Unplanted control Soils were included in the experiment. Total bacteria and phenanthrene-degrading bacteria were enumerated on plates. Diesel- and pristane-de-grading microorganisms were enumerated by the most-probable-number technique in tissue-culture plates. Results and Discussion All four types of microorganisms responded to the rhizosphere of the 6 plants in uncontaminated soil and to the diesel contaminant in unplanted soil. In contaminated rhizospheres, no effect of the plant on the hydrocarbon-degrader numbers was visible. Total bacteria responded more to the plant roots than to the contaminant. The phenanthrene-degrading bacteria and pristane-degrading microorganisms were more influenced by the contaminant than by the plants. The diesel-degrading microorganisms were equally stimulated by the plants and the contaminant. The numbers of hydrocarbon degraders were similar in the contaminated rhizospheres of the three effective plants (kiawe, kou, and milo) and in those of the three ineffective shrubs. Conclusion The results suggest the quality of the rhizodeposition is plant-dependent and governs the type of diesel-degrader populations that will be enhanced by a given plant. Recommendations and Outlook In the proposed phytoremedia-tion-benefit model plant roots maintain high levels of hydrocarbon degraders in uncontaminated soil. When the root enters a contaminated zone of soil, those hydrocarbon degraders that prefer the contaminant would switch to the contaminant as a carbon source, effectively removing the hydrocarbons. If the root exudates and the contaminant are equally attractive to the hydrocarbon degraders, the contaminant degradation would be less effective.
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Phytoremediation of petroleum hydrocarbons in tropical Coastal Soils II. microbial response to plant roots and contaminant
Environmental science and pollution research international, 2004Co-Authors: Ryan K. Jones, Wenhao H. Sun, Chung-shih Tang, Françoise M. RobertAbstract:Goal, Scope and Background. The goal of this study was to understand the interaction between plants and microorganisms during petroleum-hydrocarbon bioremediation in Pacific Islands Coastal Soils. Total bacteria and hydrocarbon-degrading microorganisms population dynamics were examined in the rhizospheres of tropical trees and shrubs, which were evaluated for their phytoremediation potential in a greenhouse experiment. The respective and combined effects of plant roots and diesel contaminant on the microbial populations were determined in relation to diesel fuel depletion. An increase in the size of the hydrocarbon-degrading populations of microbes, elicited by rhizodeposition, is generally regarded as conducive to an enhanced degradation of petroleum hydrocarbon polutants in veaetated soil.
Chung-shih Tang - One of the best experts on this subject based on the ideXlab platform.
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Phytoremediation of petroleum hydrocarbons in tropical Coastal Soils II. microbial response to plant roots and contaminant
Environmental Science and Pollution Research, 2004Co-Authors: Ryan K. Jones, Wenhao H. Sun, Chung-shih Tang, Françoise M. RobertAbstract:Goal, Scope and Background The goal of this study was to understand the interaction between plants and microorganisms during petroleum-hydrocarbon bioremediation in Pacific Islands Coastal Soils. Total bacteria and hydrocarbon-degrading microorganisms population dynamics were examined in the rhizospheres of tropical trees and shrubs, which were evaluated for their phytoremediation potential in a greenhouse experiment. The respective and combined effects of plant roots and diesel contaminant on the microbial populations were determined in relation to diesel fuel depletion. An increase in the size of the hydrocarbon-degrading populations of microbes, elicited by rhizodeposition, is generally regarded as conducive to an enhanced degradation of petroleum hydrocarbon pollutants in vegetated soil. Methods The soil was a Coastal sandy loam (pH 7.8) which was artificially contaminated with 10 g of No. 2 diesel fuel/kg soil or left uncontaminated. The pots were irrigated with fertilizer and 1% NaCl. The enumerations were carried out in the contaminated and uncontaminated rhizospheres of three trees, kiawe (Prosopis pallida) , milo (Thespesia populnea) , and kou (Cordia subcordata) and three shrubs, beach naupaka (Scaevola sericea) , false sandalwood ( Myoporum sandwicense) , and oleander (Nerium oleander ). Unplanted control Soils were included in the experiment. Total bacteria and phenanthrene-degrading bacteria were enumerated on plates. Diesel- and pristane-de-grading microorganisms were enumerated by the most-probable-number technique in tissue-culture plates. Results and Discussion All four types of microorganisms responded to the rhizosphere of the 6 plants in uncontaminated soil and to the diesel contaminant in unplanted soil. In contaminated rhizospheres, no effect of the plant on the hydrocarbon-degrader numbers was visible. Total bacteria responded more to the plant roots than to the contaminant. The phenanthrene-degrading bacteria and pristane-degrading microorganisms were more influenced by the contaminant than by the plants. The diesel-degrading microorganisms were equally stimulated by the plants and the contaminant. The numbers of hydrocarbon degraders were similar in the contaminated rhizospheres of the three effective plants (kiawe, kou, and milo) and in those of the three ineffective shrubs. Conclusion The results suggest the quality of the rhizodeposition is plant-dependent and governs the type of diesel-degrader populations that will be enhanced by a given plant. Recommendations and Outlook In the proposed phytoremedia-tion-benefit model plant roots maintain high levels of hydrocarbon degraders in uncontaminated soil. When the root enters a contaminated zone of soil, those hydrocarbon degraders that prefer the contaminant would switch to the contaminant as a carbon source, effectively removing the hydrocarbons. If the root exudates and the contaminant are equally attractive to the hydrocarbon degraders, the contaminant degradation would be less effective.
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Phytoremediation of petroleum hydrocarbons in tropical Coastal Soils II. microbial response to plant roots and contaminant
Environmental science and pollution research international, 2004Co-Authors: Ryan K. Jones, Wenhao H. Sun, Chung-shih Tang, Françoise M. RobertAbstract:Goal, Scope and Background. The goal of this study was to understand the interaction between plants and microorganisms during petroleum-hydrocarbon bioremediation in Pacific Islands Coastal Soils. Total bacteria and hydrocarbon-degrading microorganisms population dynamics were examined in the rhizospheres of tropical trees and shrubs, which were evaluated for their phytoremediation potential in a greenhouse experiment. The respective and combined effects of plant roots and diesel contaminant on the microbial populations were determined in relation to diesel fuel depletion. An increase in the size of the hydrocarbon-degrading populations of microbes, elicited by rhizodeposition, is generally regarded as conducive to an enhanced degradation of petroleum hydrocarbon polutants in veaetated soil.