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Peter Christie - One of the best experts on this subject based on the ideXlab platform.
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effects of edta and low molecular weight organic acids on Soil Solution properties of a heavy metal polluted Soil
Chemosphere, 2003Co-Authors: Y M Luo, Peter Christie, M H WongAbstract:A pot experiment was conducted to study the effects of EDTA and low molecular weight organic acids (LMWOA) on the pH, total organic carbon (TOC) and heavy metals in the Soil Solution in the rhizosphere of Brassica juncea grown in a paddy Soil contaminated with Cu, Zn, Pb and Cd. The results show that EDTA and LMWOA have no effect on the Soil Solution pH. EDTA addition significantly increased the TOC concentrations in the Soil Solution. The TOC concentrations in treatments with EDTA were significantly higher than those in treatments with LMWOA. Adding 3 mmol kg(-1) EDTA to the Soil markedly increased the total concentrations of Cu, Zn, Pb and Cd in the Soil Solution. Compared to EDTA, LMWOA had a very small effect on the metal concentrations. Total concentrations in the Soil Solution followed the sequence: EDTA >> citric acid (CA) approximately oxalic acid (OA) approximately malic acid (MA) for Cu and Pb; EDTA >> MA >> CA approximately OA for Zn; and EDTA >> MA >> CA > OA for Cd. The labile concentrations of Cu, Zn, Pb and Cd showed similar trends to the total concentrations.
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changes in Soil Solution zn and ph and uptake of zn by arbuscular mycorrhizal red clover in zn contaminated Soil
Chemosphere, 2001Co-Authors: Xiaolin Li, Peter ChristieAbstract:Abstract Red clover plants inoculated with Glomus mosseae were grown in a sterile pasture Soil containing 50 mg Zn kg −1 in ‘Plexiglas’ (acrylic) containers with nylon net partitions (30 μm mesh) designed to separate the Soil into a central root zone and two outer zones for hyphal growth with no root penetration. Two porous plastic Soil moisture samplers were installed in each pot, one in the root compartment and the other in one of the hyphal compartments. The Soil in the outer compartments was amended with one of the four application rates of Zn (as ZnSO 4 ) ranging from 0 to 1000 mg kg −1 . Non-mycorrhizal controls were included, and there were five replicates of each treatment in a randomised block in a glasshouse. Uninoculated plants received supplementary P to avoid yield limitation due to low Soil P status. Plants grew in the central compartment for nine weeks. Soil moisture samples were collected 4, 24 and 62 days after sowing to monitor changes in the Zn concentration and pH of the Soil Solution. At harvest, the mean mycorrhizal infection rate of inoculated plants ranged from 29% to 34% of total root length and was little affected by Zn application. Root and shoot yields were not affected by mycorrhizal infection. Plant Zn concentration and uptake were lower in mycorrhizal plants than non-mycorrhizal controls, and this effect was more pronounced with increasing Zn application rate to the Soil. Soil Solution Zn concentrations were lower and pH values were higher in mycorrhizal treatments than non-mycorrhizal controls and the mycorrhiza effect was more pronounced at higher Zn application rates. The protective effect of mycorrhiza against plant Zn uptake may have been associated with changes in Zn solubility mediated by changes in the Soil Solution pH, or by immobilisation of Zn in the extraradical mycelium.
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Soil Solution zn and ph dynamics in non rhizosphere Soil and in the rhizosphere of thlaspi caerulescens grown in a zn cd contaminated Soil
Chemosphere, 2000Co-Authors: Peter Christie, A J M BakerAbstract:Abstract Temporal changes in Soil Solution properties and metal speciation were studied in non-rhizosphere Soil and in the rhizosphere of the hyperaccumulator Thlaspi caerulescens J. & C. Presl (population from Prayon, Belgium) grown in a Zn- and Cd-contaminated Soil. This paper focuses on Soil Solution Zn and pH dynamics during phytoextraction. The concentration of Zn in both non-rhizosphere and rhizosphere Soil Solutions decreased from 23 mg/l at the beginning to 2 mg/l at the end of the experiment (84 days after transplanting of seedlings), mainly due to chemical sorption. There was no significant difference in overall Zn concentration between the planted and the unplanted Soil Solutions (P > 0.05). Soil Solution pH decreased initially and then increased slightly in both planted and unplanted Soil zones. From 60 to 84 days after transplanting, the pH of the rhizosphere Soil Solution was higher than that of non-rhizosphere Soil Solution (P
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influence of lime stabilized sewage sludge cake on heavy metals and dissolved organic substances in the Soil Solution
Humic Substances Peats and Sludges#R##N#Health and Environmental Aspects, 1997Co-Authors: Yongming Luo, Peter ChristieAbstract:A randomised block glasshouse experiment was carried out in which barley plants (Hordeum vulgare L.) were grown for 40 days after seed germination in two contrasting arable Soils following incorporation of a lime stabilized sewage sludge cake at rates equivalent to 0, 30, 90 and 120 t fresh product ha−1. Some short term effects of the sludge product on dissolved organic substances (DOS) and heavy metal concentrations in the Soil Solution were studied. Soil Solution (passed through a < 0.20 μm pore size filter) was extracted from Soil sub samples (500 g from each pot) by a centrifugation and Filtration method. The Solution was analyzed immediately for DOS (predicted by absorbance at 360 nm) and for four heavy metals (Cu, Zn, Ni, and Cr). Concentrations of Cd and Pb were too low to be detected. The concentrations of DOS increased significantly in both Soils with increasing application rate of the sludge material. Increasing the application rate also led to an increase in the concentrations of Cu, Ni, and Cr in the Soil Solution, although the proportions of the metals applied that were found in the Soil Solution were small. The sludge product had no overall effect on the concentrations of Zn in the Soil Solution. The effect on Soil Solution concentrations of DOS and Cu, Ni, and Cr was related to Soil type. Significant positive correlations between each of these three metals and DOS were also observed. The findings indicate that DOS derived from the sewage sludge may have affected the concentrations of Cu, Ni, and Cr in the Soil Solution and that these metals may be mobile, largely as metal-organic complexes in the Soils.
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effect of alkaline stabilized sewage sludge solids on chemical speciation and plant availability of cu and zn in the rhizosphere Soil Solution
1997Co-Authors: Yongming Luo, Peter ChristieAbstract:Perennial ryegrass (Lolium perenne cv. Magella) was grown in a glasshouse experiment in which nylon mesh bags separated the Soil into ‘rhizosphere’ and ‘non-rhizosphere’ zones. The Soil was mixed with four application rates of an organic fertiliser made by mixing sewage sludge cake with cement kiln dust and composting. Soil Solution was obtained by low speed centrifugation and filtration after addition of water (1:1 Soil:Solution ratio). A resin exchange method was used to distinguish between labile and non-labile forms of dissolved copper (Cu) and zinc (Zn). Soil Solution pH, electrical conductivity (EC), absorbance at 360 nm (A360) and Cu and Zn were determined, together with plant (shoot + root) Cu and Zn concentration and uptake.
Ping Liang - One of the best experts on this subject based on the ideXlab platform.
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stress corrosion cracking of x80 pipeline steel in simulated alkaline Soil Solution
Materials & Design, 2009Co-Authors: Ping Liang, Xu ChenAbstract:Abstract The stress corrosion cracking susceptibility of X80 steel under applied cathodic potentials in a simulated Soil Solution was investigated using slow strain rate tensile tests. The fracture surfaces were observed by scanning electron microscopy. No apparent change of reduction in area was found at −775 mV in contrast to the open circuit potential. Many dimples were visible on both fracture surfaces. However, when the applied potentials were lower than −1000 mV, the SCC susceptibility increased as a result of evolution hydrogen, which diffuses into the steel. Pitts were found to be an important factor in the initiation of cracks.
Wilcke Wolfgang - One of the best experts on this subject based on the ideXlab platform.
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Dissolved phosphorus in Soil Solution of the Jena Experiment (Main Experiment, year 2002)
PANGAEA, 2015Co-Authors: Oelmann Yvonne, Rosenkranz Stephan, Wilcke WolfgangAbstract:This data set contains measurements of dissolved phosphorus (total dissolved nitrogen: TDP, dissolved inorganic phosphorus: PO4P and dissolved organic phosphorus: DOP) in samples of Soil water collected in 2002 from the main experiment plots of a large grassland biodiversity experiment (the Jena Experiment; see further details below). In the main experiment, 82 grassland plots of 20 x 20 m were established from a pool of 60 species belonging to four functional groups (grasses, legumes, tall and small herbs). In May 2002, varying numbers of plant species from this species pool were sown into the plots to create a gradient of plant species richness (1, 2, 4, 8, 16 and 60 species) and functional richness (1, 2, 3, 4 functional groups). Plots were maintained by bi-annual weeding and mowing. Glass suction plates with a diameter of 12 cm, 1 cm thickness and a pore size of 1–1.6 µm (UMS GmbH, Munich, Germany) were installed in April 2002 in depths of 10, 20, 30 and 60 cm to collect Soil Solution. Manual Soil matric potential measurements were used to regulate the vacuum system. The sampling bottles were continuously evacuated to a negative pressure between 50 and 350 mbar, such that the suction pressure was about 50 mbar above the actual Soil water tension. Thus, only the Soil leachate was collected. Cumulative Soil Solution was sampled bi-weekly, in 2002 at the 23.10.2002; 05.11.2002; 20.11.2002; 05.12.2002; and 28.12.2002, and analyzed for dissolved inorganic P (PO4P) and total dissolved phosphorus (TDP). Inorganic phosphorus concentrations in the Soil Solution were measured photometrically with a continuous flow analyzer (CFA SAN++, Skalar [Breda, The Netherlands]). Ammonium molybdate catalyzed by antimony tartrate reacts in an acidic medium with phosphate and forms a phospho-molybdic acid complex. Ascorbic acid reduces this complex to an intensely blue-colored complex. Total dissolved P in Soil Solution was analyzed by irradiation with UV and oxidation with K2S2O8 followed by reaction with ammonium molybdate (Skalar catnr. 503-553w/r). As the molybdic complex forms under strongly acidic conditions, we could not exclude the hydrolysis of labile organic P compounds in our samples. Furthermore, the molybdate reaction is not sensitive for condensed phosphates. The detection limits of both TDP and PO4P were 0.02 mg P l-1 (CFA, Skalar). Dissolved organic P (DOP) in Soil Solution was calculated as the difference between TDP and PO4P. In a low number of samples, TDP was equal to or smaller than PO4P; in these cases, DOP was assumed to be zero
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Dissolved phosphorus in Soil Solution of the Jena Experiment (Main Experiment, year 2003)
PANGAEA, 2015Co-Authors: Oelmann Yvonne, Rosenkranz Stephan, Wilcke WolfgangAbstract:This data set contains measurements of dissolved phosphorus (total dissolved nitrogen: TDP, dissolved inorganic phosphorus: PO4P and dissolved organic phosphorus: DOP) in samples of Soil water collected in 2003 from the main experiment plots of a large grassland biodiversity experiment (the Jena Experiment; see further details below). In the main experiment, 82 grassland plots of 20 x 20 m were established from a pool of 60 species belonging to four functional groups (grasses, legumes, tall and small herbs). In May 2002, varying numbers of plant species from this species pool were sown into the plots to create a gradient of plant species richness (1, 2, 4, 8, 16 and 60 species) and functional richness (1, 2, 3, 4 functional groups). Plots were maintained by bi-annual weeding and mowing. Glass suction plates with a diameter of 12 cm, 1 cm thickness and a pore size of 1–1.6 mm (UMS GmbH, Munich, Germany) were installed in April 2002 in depths of 10, 20, 30 and 60 cm to collect Soil Solution. Manual Soil matric potential measurements were used to regulate the vacuum system. The sampling bottles were continuously evacuated to a negative pressure between 50 and 350 mbar, such that the suction pressure was about 50 mbar above the actual Soil water tension. Thus, only the Soil leachate was collected. Cumulative Soil Solution was sampled bi-weekly, in 2003 at the 07.03.2003; 24.03.2003; 07.04.2003; 22.04.2003; 07.05.2003; 20.05.2003; 03.06.2003; 28.07.2003; 12.09.2003; 22.09.2003; 07.10.2003; and 21.10.2003, and analyzed for dissolved inorganic P (PO4P) and total dissolved phosphorus (TDP). Inorganic phosphorus concentrations in the Soil Solution were measured photometrically with a continuous flow analyzer (CFA SAN++, Skalar [Breda, The Netherlands]). Ammonium molybdate catalyzed by antimony tartrate reacts in an acidic medium with phosphate and forms a phospho-molybdic acid complex. Ascorbic acid reduces this complex to an intensely blue-colored complex. Total dissolved P in Soil Solution was analyzed by irradiation with UV and oxidation with K2S2O8 followed by reaction with ammonium molybdate (Skalar catnr. 503-553w/r). As the molybdic complex forms under strongly acidic conditions, we could not exclude the hydrolysis of labile organic P compounds in our samples. Furthermore, the molybdate reaction is not sensitive for condensed phosphates. The detection limits of both TDP and PO4P were 0.02 mg P l-1 (CFA, Skalar). Dissolved organic P (DOP) in Soil Solution was calculated as the difference between TDP and PO4P. In a low number of samples, TDP was equal to or smaller than PO4P; in these cases, DOP was assumed to be zero
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Dissolved phosphorus in Soil Solution of the Jena Experiment (Main Experiment, year 2004)
PANGAEA, 2015Co-Authors: Oelmann Yvonne, Rosenkranz Stephan, Wilcke WolfgangAbstract:This data set contains measurements of dissolved phosphorus (total dissolved nitrogen: TDP, dissolved inorganic phosphorus: PO4P and dissolved organic phosphorus: DOP) in samples of Soil water collected in 2004 from the main experiment plots of a large grassland biodiversity experiment (the Jena Experiment; see further details below). In the main experiment, 82 grassland plots of 20 x 20 m were established from a pool of 60 species belonging to four functional groups (grasses, legumes, tall and small herbs). In May 2002, varying numbers of plant species from this species pool were sown into the plots to create a gradient of plant species richness (1, 2, 4, 8, 16 and 60 species) and functional richness (1, 2, 3, 4 functional groups). Plots were maintained by bi-annual weeding and mowing. Glass suction plates with a diameter of 12 cm, 1 cm thickness and a pore size of 1–1.6 µm (UMS GmbH, Munich, Germany) were installed in April 2002 in depths of 10, 20, 30 and 60 cm to collect Soil Solution. Manual Soil matric potential measurements were used to regulate the vacuum system. The sampling bottles were continuously evacuated to a negative pressure between 50 and 350 mbar, such that the suction pressure was about 50 mbar above the actual Soil water tension. Thus, only the Soil leachate was collected. Cumulative Soil Solution was sampled bi-weekly, in 2004 at the 15.01.2004; 30.01.2004; 12.02.2004; 27.02.2004; 09.03.2004; 25.03.2004; 21.04.2004; 07.05.2004; and 24.05.2004, and analyzed for dissolved inorganic P (PO4P) and total dissolved phosphorus (TDP). Inorganic phosphorus concentrations in the Soil Solution were measured photometrically with a continuous flow analyzer (for samples collected until spring 2004: CFA SAN++, Skalar [Breda, The Netherlands]; for samples collected later: CFA Autoanalyzer [Bran&Luebbe, Norderstedt, Germany]). Ammonium molybdate catalyzed by antimony tartrate reacts in an acidic medium with phosphate and forms a phospho-molybdic acid complex. Ascorbic acid reduces this complex to an intensely blue-colored complex. Total dissolved P in Soil Solution was analyzed by irradiation with UV and oxidation with K2S2O8 followed by reaction with ammonium molybdate (Skalar catnr. 503-553w/r). As the molybdic complex forms under strongly acidic conditions, we could not exclude the hydrolysis of labile organic P compounds in our samples. Furthermore, the molybdate reaction is not sensitive for condensed phosphates. The detection limits of both TDP and PO4P were 0.02 mg P l-1 (CFA, Skalar) and 0.04 mg P l-1 (Autoanalyzer, Bran&Luebbe). Dissolved organic P (DOP) in Soil Solution was calculated as the difference between TDP and PO4P. In a low number of samples, TDP was equal to or smaller than PO4P; in these cases, DOP was assumed to be zero
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Seasonally aggregated values of dissolved inorganic phosphorus in Soil Solution of the Jena Experiment (Main Experiment, year 2005)
PANGAEA, 2015Co-Authors: Oelmann Yvonne, Wilcke WolfgangAbstract:This data set contains measurements of inorganic phosphorus in samples of Soil Solution collected in 2005 from the main experiment plots of a large grassland biodiversity experiment (the Jena Experiment; see further details below) that have been aggregated to seasonal values. In the main experiment, 82 grassland plots of 20 x 20 m were established from a pool of 60 species belonging to four functional groups (grasses, legumes, tall and small herbs). In May 2002, varying numbers of plant species from this species pool were sown into the plots to create a gradient of plant species richness (1, 2, 4, 8, 16 and 60 species) and functional richness (1, 2, 3, 4 functional groups). Plots were maintained by bi-annual weeding and mowing. Glass suction plates with a diameter of 12 cm, 1 cm thickness and a pore size of 1–1.6 µm (UMS GmbH, Munich, Germany) were installed in April 2002 in depths of 10, 20, 30 and 60 cm to collect Soil Solution. Manual Soil matric potential measurements were used to regulate the vacuum system. Manual Soil matric potential measurements were used to regulate the vacuum system. The sampling bottles were continuously evacuated to a negative pressure between 50 and 350 mbar, such that the suction pressure was about 50 mbar above the actual Soil water tension. Thus, only the Soil leachate was collected. Cumulative Soil Solution was sampled biweekly and analyzed for dissolved inorganic P (PO4P). Here volume-weighted mean values are provided as aggregated seasonal values (spring = March to May, summer = June to August, fall = September to November, winter = December to February) for 2005 in spring, and winter. To calculate these values, the sampled volume of Soil Solution is used as weight for P concentrations of the respective sampling date. Inorganic phosphorus concentrations in the Soil Solution were measured photometrically with a continuous flow analyzer (CFA Autoanalyzer [Bran&Luebbe, Norderstedt, Germany]). Ammonium molybdate catalyzed by antimony tartrate reacts in an acidic medium with phosphate and forms a phospho-molybdic acid complex. Ascorbic acid reduces this complex to an intensely blue-colored complex. As the molybdic complex forms under strongly acidic conditions, we could not exclude the hydrolysis of labile organic P compounds in our samples. Furthermore, the molybdate reaction is not sensitive for condensed phosphates. The detection limits of both TDP and PO4P were 0.04 mg P l-1 (Autoanalyzer, Bran&Luebbe)
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Seasonally aggregated values of dissolved inorganic phosphorus in Soil Solution of the Jena Experiment (Main Experiment, year 2003)
PANGAEA, 2015Co-Authors: Oelmann Yvonne, Wilcke WolfgangAbstract:This data set contains measurements of inorganic phosphorus in samples of Soil Solution collected in 2003 from the main experiment plots of a large grassland biodiversity experiment (the Jena Experiment; see further details below) that have been aggregated to seasonal values. In the main experiment, 82 grassland plots of 20 x 20 m were established from a pool of 60 species belonging to four functional groups (grasses, legumes, tall and small herbs). In May 2002, varying numbers of plant species from this species pool were sown into the plots to create a gradient of plant species richness (1, 2, 4, 8, 16 and 60 species) and functional richness (1, 2, 3, 4 functional groups). Plots were maintained by bi-annual weeding and mowing. Glass suction plates with a diameter of 12 cm, 1 cm thickness and a pore size of 1–1.6 µm (UMS GmbH, Munich, Germany) were installed in April 2002 in depths of 10, 20, 30 and 60 cm to collect Soil Solution. Manual Soil matric potential measurements were used to regulate the vacuum system. Manual Soil matric potential measurements were used to regulate the vacuum system. The sampling bottles were continuously evacuated to a negative pressure between 50 and 350 mbar, such that the suction pressure was about 50 mbar above the actual Soil water tension. Thus, only the Soil leachate was collected. Cumulative Soil Solution was sampled biweekly and analyzed for dissolved inorganic P (PO4P). Here volume-weighted mean values are provided as aggregated seasonal values (spring = March to May, summer = June to August, fall = September to November, winter = December to February) for 2003 in spring, fall, and winter. To calculate these values, the sampled volume of Soil Solution is used as weight for P concentrations of the respective sampling date. Inorganic phosphorus concentrations in the Soil Solution were measured photometrically with a continuous flow analyzer (CFA SAN++, Skalar [Breda, The Netherlands]). Ammonium molybdate catalyzed by antimony tartrate reacts in an acidic medium with phosphate and forms a phospho-molybdic acid complex. Ascorbic acid reduces this complex to an intensely blue-colored complex. As the molybdic complex forms under strongly acidic conditions, we could not exclude the hydrolysis of labile organic P compounds in our samples. Furthermore, the molybdate reaction is not sensitive for condensed phosphates. The detection limits of both TDP and PO4P were 0.02 mg P l-1 (CFA, Skalar)
A J M Baker - One of the best experts on this subject based on the ideXlab platform.
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Soil Solution zn and ph dynamics in non rhizosphere Soil and in the rhizosphere of thlaspi caerulescens grown in a zn cd contaminated Soil
Chemosphere, 2000Co-Authors: Peter Christie, A J M BakerAbstract:Abstract Temporal changes in Soil Solution properties and metal speciation were studied in non-rhizosphere Soil and in the rhizosphere of the hyperaccumulator Thlaspi caerulescens J. & C. Presl (population from Prayon, Belgium) grown in a Zn- and Cd-contaminated Soil. This paper focuses on Soil Solution Zn and pH dynamics during phytoextraction. The concentration of Zn in both non-rhizosphere and rhizosphere Soil Solutions decreased from 23 mg/l at the beginning to 2 mg/l at the end of the experiment (84 days after transplanting of seedlings), mainly due to chemical sorption. There was no significant difference in overall Zn concentration between the planted and the unplanted Soil Solutions (P > 0.05). Soil Solution pH decreased initially and then increased slightly in both planted and unplanted Soil zones. From 60 to 84 days after transplanting, the pH of the rhizosphere Soil Solution was higher than that of non-rhizosphere Soil Solution (P
Xu Chen - One of the best experts on this subject based on the ideXlab platform.
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stress corrosion cracking of x80 pipeline steel in simulated alkaline Soil Solution
Materials & Design, 2009Co-Authors: Ping Liang, Xu ChenAbstract:Abstract The stress corrosion cracking susceptibility of X80 steel under applied cathodic potentials in a simulated Soil Solution was investigated using slow strain rate tensile tests. The fracture surfaces were observed by scanning electron microscopy. No apparent change of reduction in area was found at −775 mV in contrast to the open circuit potential. Many dimples were visible on both fracture surfaces. However, when the applied potentials were lower than −1000 mV, the SCC susceptibility increased as a result of evolution hydrogen, which diffuses into the steel. Pitts were found to be an important factor in the initiation of cracks.
