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  • 1
    Language: English
    In: Geoderma, Dec, 2014, Vol.235-236, p.127(6)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.geoderma.2014.07.003 Byline: Dorit Julich, Stefan Gath Abstract: Metallic nanoparticles have special physical and chemical properties which determine a particular behavior in environmental systems and organisms. While several studies investigated the differences in the toxicity of metallic nanoparticles compared to their ionic forms or salts, there is little knowledge about processes in complex environmental media. For instance, the sorption processes in soils crucially influence accumulation, transport and/or release into other media (water, biota, etc.). Our study assessed the sorptivity of copper oxide nanoparticles (CuO-NPs) in comparison to copper ions (Cu.sup.2+) in batch experiments. The results showed significant differences in the solid to liquid distribution at equilibrium and indicated much stronger sorption of CuO-NPs at soil components compared to Cu.sup.2+. The sorption isotherms of both variants were fitted to the Freundlich equation showing clear differences of the Freundlich parameters K.sub.F and n. The values for Cu.sup.2+ sorption were in the range of agricultural soils in Germany (log K.sub.F : 2.6-4.1, n: 0.9-1.6). On the contrary the isotherms for the CuO-NP experiments were strongly shifted to the solid phase (log K.sub.F : 4.0-9.0, n: 1.3-3.7). Both Cu.sup.2+ and CuO-NP sorptions (expressed as log K.sub.F) were significantly correlated (P〈0.05) to pH, carbonates, soil organic carbon and amorphous Fe in the soils. However, a larger data set is needed to generate reliable statistical results. Further, more research is required to identify reasons for the detected differences in sorption behavior between nanoparticulate copper and copper ions. Article History: Received 6 September 2013; Revised 23 June 2014; Accepted 6 July 2014
    Keywords: Nanoparticles -- Chemical Properties ; Nanoparticles -- Comparative Analysis ; Copper Oxides -- Chemical Properties ; Copper Oxides -- Comparative Analysis ; Soils -- Chemical Properties ; Soils -- Comparative Analysis ; Soil Carbon -- Chemical Properties ; Soil Carbon -- Comparative Analysis
    ISSN: 0016-7061
    Source: Cengage Learning, Inc.
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  • 2
    Language: English
    In: Journal of Plant Nutrition and Soil Science, June 2017, Vol.180(3), pp.407-417
    Description: Phosphorus (P) is primarily transported in soil through preferential flow pathways (PFP), which can rapidly move water and matter bypassing large portions of the soil. This study investigated the composition of P forms in PFPs and soil matrix in two profiles at a forested hillslope in the Thuringian Forest (Central Germany), in order to evaluate (1) the effect of PFPs on the distribution of P fractions in forest soils, and (2) how hillslope position influences P fractions and other chemical parameters. To characterize water and mass fluxes in the profiles, flow pathways were visualized using dye tracer experiments. Stained and unstained soil material was sampled to assess differences of chemical parameters in the PFPs and soil matrix, and tested for correlations between chemical parameters to determine the factors influencing P fractions in soils. The results revealed significantly higher P contents (total P and most P fractions) in the upslope profile compared to the downslope profile. This accumulation effect in the upper profile was also observed for C, N, Fe, and Mn. The distribution of flow patterns also differed between the two profiles with stronger vertical infiltration into mineral soil and more preferential flow along stones and roots in the upslope profile compared to the downslope profile. However, the observed difference could not be addressed to hillslope effects as both test plots were located in mid‐slope position, but were strongly influenced by spatial heterogeneity (., micro‐relief). Furthermore, no statistically significant accumulation effect of P or other elements in PFPs compared to soil matrix was found. At the test site, the combination of high stone content with low potential for P sorption, and predominance of near‐surface lateral flow, appears to have hampered the development of gradients in chemical parameters between PFPs and soil matrix.
    Keywords: Phosphorus Fractions ; Forest Soil ; Hillslope Processes ; Preferential Flow ; Pfp
    ISSN: 1436-8730
    E-ISSN: 1522-2624
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  • 3
    Language: English
    In: Geoderma, December 2014, Vol.235-236, pp.127-132
    Description: Metallic nanoparticles have special physical and chemical properties which determine a particular behavior in environmental systems and organisms. While several studies investigated the differences in the toxicity of metallic nanoparticles compared to their ionic forms or salts, there is little knowledge about processes in complex environmental media. For instance, the sorption processes in soils crucially influence accumulation, transport and/or release into other media (water, biota, etc.). Our study assessed the sorptivity of copper oxide nanoparticles (CuO-NPs) in comparison to copper ions (Cu ) in batch experiments. The results showed significant differences in the solid to liquid distribution at equilibrium and indicated much stronger sorption of CuO-NPs at soil components compared to Cu . The sorption isotherms of both variants were fitted to the Freundlich equation showing clear differences of the Freundlich parameters and . The values for Cu sorption were in the range of agricultural soils in Germany (log : 2.6–4.1, : 0.9–1.6). On the contrary the isotherms for the CuO-NP experiments were strongly shifted to the solid phase (log : 4.0–9.0, : 1.3–3.7). Both Cu and CuO-NP sorptions (expressed as log ) were significantly correlated (P 〈 0.05) to pH, carbonates, soil organic carbon and amorphous Fe in the soils. However, a larger data set is needed to generate reliable statistical results. Further, more research is required to identify reasons for the detected differences in sorption behavior between nanoparticulate copper and copper ions.
    Keywords: Copper Nanoparticles ; Copper ; Sorption ; Freundlich Isotherm ; Agriculture
    ISSN: 0016-7061
    E-ISSN: 1872-6259
    Source: ScienceDirect Journals (Elsevier)
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  • 4
    Language: English
    In: Water, Air, & Soil Pollution, 2012, Vol.223(7), pp.3589-3599
    Description: The validation of metal balancing tools is usually based on the comparison of simulated versus observed data. In our study, we applied a set of different relative and absolute criteria to evaluate the performance of the model Assessment Tool for Metals in Soils. In this process, the uncertainty of the model output and the sensitivity of model parameters were also assessed. The study includes data from 123 agricultural used top soils which are characterized by the application of different fertilizers (mineral and farmyard fertilizers, sewage sludge) resulting in diverse metal inputs into the soil. Although the most common validation criteria (coefficient of determination, error ratio between prediction and observation) indicated a good model performance in predicting the metal contents over a simulation period, the absolute measure (mean absolute difference between prediction and observation) showed that the informational value of the validation results was limited for several sites. Therefore sites with short simulation periods and/or low metal inputs are not suitable for validation, because the model uncertainty covers the metal concentration changes. Excluding such sites from the validation statistics led to evaluable and quite better validation results. Although the calculated output uncertainty was low, a further reduction can be realized by improving the database for the identified sensitive parameters (initial soil metal content and fertilizers metal concentration).
    Keywords: Efficiency criteria ; Validation ; Model uncertainty ; Sensitivity analysis ; Heavy metals
    ISSN: 0049-6979
    E-ISSN: 1573-2932
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  • 5
    Language: English
    In: Forests, 01 June 2017, Vol.8(6), p.206
    Description: Phosphorus (P) export from forest soils is mainly driven by storm events, which induce rapid flow processes by preferential flow bypassing large parts of the soil matrix. However, little is known about the dynamics, magnitude, and driving processes of P exports into surface waters. In this paper, we present the results of a monitoring study in a small forested catchment (21 ha) situated in the low mountain ranges of Saxony, Germany. During the fixed schedule-sampling (weekly to bi-weekly sampling frequency for a three-year period), a mean total-P concentration of 8 μg·L−1 was measured. However, concentrations increased up to 203 μg·L−1 during individual storm flow events. Based on the analyzed concentrations and continuously measured discharge we calculated mean annual export rates of 19 to 44 g·ha−1·a−1 for the weekly sampling frequency with different load calculation methods. If events are included into the annual load calculation, the mean annual export fluxes can be up to 83 g·ha−1·a−1 based on the different load calculation methods. Predictions of total-P export rates based on a sampling strategy which does not consider short-term changes due to factors such as storms will substantially underestimate P exports.
    Keywords: Forested Catchments ; Phosphorus Exports ; Load Calculations ; Forestry
    E-ISSN: 1999-4907
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  • 6
    Language: English
    In: Forests, 01 December 2016, Vol.8(1), p.19
    Description: The transport of nutrients in forest soils predominantly occurs along preferential flow pathways (PFP). This study investigated the composition of phosphorus (P) forms in PFPs and soil matrix in several temperate beech forests with contrasting soil P contents in Germany. The PFPs were visualized using dye tracer experiments. Stained and unstained soil was sampled from three profile cuts per plot and analyzed for P fractions. The results show that labile P concentrations were highest in the O-layer and had the same range of values at all sites (240–320 mg·kg−1), although total P (TP) differed considerably (530–2330 mg·kg−1). The ratio of labile P to TP was significantly lower in the P-rich soil compared to the medium and P-poor soils. By contrast, the ratio of moderately labile P to TP was highest at the P-rich site. The shifts in P fractions with soil depth were generally gradual in the P-rich soil, but more abrupt at the others. The contents of labile and moderately labile P clearly differed in PFPs compared to soil matrix, but not statistically significant. The studied soils are characterized by high stone contents with low potential for P sorption. However, indications were found that labile organically bound P accumulates in PFPs such as biopores.
    Keywords: Phosphorus Fractions ; Forest Soil ; Preferential Flow ; Pfp ; Forestry
    E-ISSN: 1999-4907
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  • 7
    Language: English
    In: 2015
    Keywords: Soil Organic Carbon ; Data Collection ; Sorption ; Sorption ; Sorption Isotherms ; Toxicity ; Agricultural Soils ; Cupric Oxide ; Freundlich Isotherm ; Copper ; Nanoparticles ; Carbonates ; Copper Nanoparticles ; Iron
    Source: AGRIS (Food and Agriculture Organization of the United Nations)
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  • 8
    Dissertation
    Dissertation
    Molecular Diversity Preservation International (MDPI)
    Language: English
    Description: The transport of nutrients in forest soils predominantly occurs along preferential flow pathways (PFP). This study investigated the composition of phosphorus (P) forms in PFPs and soil matrix in several temperate beech forests with contrasting soil P contents in Germany. The PFPs were visualized using dye tracer experiments. Stained and unstained soil was sampled from three profile cuts per plot and analyzed for P fractions. The results show that labile P concentrations were highest in the O-layer and had the same range of values at all sites (240–320 mg·kg−1), although total P (TP) differed considerably (530–2330 mg·kg−1). The ratio of labile P to TP was significantly lower in the P-rich soil compared to the medium and P-poor soils. By contrast, the ratio of moderately labile P to TP was highest at the P-rich site. The shifts in P fractions with soil depth were generally gradual in the P-rich soil, but more abrupt at the others. The contents of labile and moderately labile P clearly differed in PFPs compared to soil matrix, but not statistically significant. The studied soils are characterized by high stone contents with low potential for P sorption. However, indications were found that labile organically bound P accumulates in PFPs such as biopores.
    Keywords: Info:Eu-Repo/Classification/Ddc/630 ; Ddc:630 ; Phosphorfraktionen ; Waldboden ; Vorzugsstrom ; Pfp ; Tu Dresden ; Publikationsfonds ; Phosphorus Fractions ; Forest Soil ; Preferential Flow ; Pfp ; Tu Dresden ; Publishing Fund
    Source: Networked Digital Library of Theses and Dissertations
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  • 9
    Language: English
    Description: Phosphorus (P) export from forest soils is mainly driven by storm events, which induce rapid flow processes by preferential flow bypassing large parts of the soil matrix. However, little is known about the dynamics, magnitude, and driving processes of P exports into surface waters. In this paper, we present the results of a monitoring study in a small forested catchment (21 ha) situated in the low mountain ranges of Saxony, Germany. During the fixed schedule-sampling (weekly to bi-weekly sampling frequency for a three-year period), a mean total-P concentration of 8 μg·L−1 was measured. However, concentrations increased up to 203 μg·L−1 during individual storm flow events. Based on the analyzed concentrations and continuously measured discharge we calculated mean annual export rates of 19 to 44 g·ha−1·a−1 for the weekly sampling frequency with different load calculation methods. If events are included into the annual load calculation, the mean annual export fluxes can be up to 83 g·ha−1·a−1 based on the different load calculation methods. Predictions of total-P export rates based on a sampling strategy which does not consider short-term changes due to factors such as storms will substantially underestimate P exports.
    Keywords: Info:Eu-Repo/Classification/Ddc/630 ; Ddc:630 ; Bewaldete Einzugsgebiete ; Phosphorexporte ; Lastberechnungen ; Technische Universität Dresden ; Publikationsfond ; Forested Catchments ; Phosphorus Exports ; Load Calculations ; Technische Universität Dresden ; Publishung Fund
    Source: Networked Digital Library of Theses and Dissertations
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  • 10
    Language: English
    In: Journal of Plant Nutrition and Soil Science, August 2016, Vol.179(4), pp.425-438
    Description: Understanding and quantification of phosphorus (P) fluxes are key requirements for predictions of future forest ecosystems changes as well as for transferring lessons learned from natural ecosystems to croplands and plantations. This review summarizes and evaluates the recent knowledge on mechanisms, magnitude, and relevance by which dissolved and colloidal inorganic and organic P forms can be translocated within or exported from forest ecosystems. Attention is paid to hydrological pathways of P losses at the soil profile and landscape scales, and the subsequent influence of P on aquatic ecosystems. New (unpublished) data from the German Priority Program 1685 “” were added to provide up‐to‐date flux‐based information. Nitrogen (N) additions increase the release of water‐transportable P forms. Most P found in percolates and pore waters belongs to the so‐called dissolved organic P (DOP) fractions, rich in orthophosphate‐monoesters and also containing some orthophosphate‐diesters. Total solution P concentrations range from ca. 1 to 400 µg P L, with large variations among forest stands. Recent sophisticated analyses revealed that large portions of the DOP in forest stream water can comprise natural nanoparticles and fine colloids which under extreme conditions may account for 40–100% of the P losses. Their translocation within preferential flow passes may be rapid, mediated by storm events. The potential total P loss through leaching into subsoils and with streams was found to be less than 50 mg P m a, suggesting effects on ecosystems at centennial to millennium scale. All current data are based on selected snapshots only. Quantitative measurements of P fluxes in temperate forest systems are nearly absent in the literature, probably due to main research focus on the C and N cycles. Therefore, we lack complete ecosystem‐based assessments of dissolved and colloidal P fluxes within and from temperate forest systems.
    Keywords: Forest Ecosystem ; Phosphorus ; Fluxes ; Soil ; Processes ; Hydrology
    ISSN: 1436-8730
    E-ISSN: 1522-2624
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