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  • Adam, Christian (49)
  • Vogel, Christian (24)
  • Krüger, Oliver (11)
  • Peplinski, Burkhard (9)
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  • Herzel, Hannes (6)
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  • Simon, Franz-Georg (5)
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  • Zeitschriftenartikel (48)
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Referierte Publikation

  • ja (49) (entfernen)

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  • Sewage sludge ash (21)
  • Phosphorus recovery (9)
  • Phosphorus (6)
  • Thermochemical treatment (6)
  • Soil (4)
  • Aluminium phosphate (3)
  • Fertilizer (3)
  • Klärschlammasche (3)
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  • Raman microspectroscopy (3)
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Organisationseinheit der BAM

  • 4 Material und Umwelt (34)
  • 4.4 Thermochemische Reststoffbehandlung und Wertstoffrückgewinnung (33)
  • 1 Analytische Chemie; Referenzmaterialien (5)
  • 1.3 Strukturanalytik (4)
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  • 5.6 Glas (3)
  • 1.4 Prozessanalytik (2)
  • 4.3 Schadstofftransfer und Umwelttechnologien (2)
  • 1.0 Abteilungsleitung und andere (1)
  • 4.0 Abteilungsleitung und andere (1)
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Nanocrystalline and stacking-disordered beta-cristobalite AlPO4 chemically stabilized at room temperature: synthesis, physical characterization, and X-ray powder diffraction data (2017)
Peplinski, Burkhard ; Adamczyk, Burkart ; Formanek, P. ; Meyer, Christian ; Krüger, O. ; Scharf, Holger ; Reinsch, Stefan ; Ostermann, Markus ; Nofz, Marianne ; Jäger, Christian ; Adam, Christian ; Emmerling, Franziska
This paper reports the first successful synthesis and the structural characterization of nanocrystalline and stacking-disordered β-cristobalite AlPO4 that is chemically stabilized down to room temperature and free of crystalline impurity phases. Several batches of the title compound were synthesized and thoroughly characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy mapping in SEM, solid-state 31P nuclear magnetic resonance (31P-NMR) spectroscopy including the TRAPDOR method, differential thermal analysis (DTA), gas-sorption methods, optical Emission spectroscopy, X-ray fluorescence spectroscopy, and ion chromatography. Parameters that are critical for the synthesis were identified and optimized. The synthesis procedure yields reproducible results and is well documented. A high-quality XRD pattern of the title compound is presented, which was collected with monochromatic copper radiation at room temperature in a wide 2θ range of 5°–100°.
Characterization of phosphorus compounds in soils by deep ultraviolet (DUV) Raman microspectroscopy (2017)
Vogel, Christian ; Ramsteiner, M. ; Sekine, R. ; Doolette, A. ; Adam, Christian
Deep ultraviolet Raman microspectroscopy was successfully investigated as a new approach to analyze the chemical state of phosphorus compounds directly in soil. We demonstrate that ultraviolet excitation has the advantage to avoid the interference with the strong fluorescence, which occurs in the visible spectral range caused by organic matter in soils. Furthermore, the spatial resolution of <1 μm2 enables the detection of very small phosphorus particles. For some organic phosphorus compounds (β-glycerophosphate, aminomethylphosphonic acid), sample cooling to -100 °C is found to strongly reduce the rate of degradation induced by the illumination with the ultraviolet excitation light. However, phytic acid and adenosine monophosphate degraded even with cooling. Our results reveal the capability of deep ultraviolet Raman microspectroscopy as a high-resolution benchtop imaging technique for the analysis of local interactions between soil compounds with the potential to become an analytical key to improve the understanding of transformation mechanisms of phosphates as well as other mineral phases in soils.
Determination of phosphate phases in sewage sludge ash-based fertilizers by Raman microspectroscopy (2013)
Vogel, Christian ; Adam, Christian ; McNaughton, D.
The chemical form of phosphate phases in sewage sludge ash (SSA)-based fertilizers was determined by Raman microspectroscopy. Raman mapping with a lateral resolution of 5 × 5 µm² easily detected different compounds present in the fertilizers with the help of recorded reference spectra of pure substances. Quartz and aluminosilicates showed Raman bands in the range of 450-520 cm-1. Phosphates with apatite structure and magnesium triphosphate were determined at around 960 and 980 cm-1, respectively. Furthermore, calcium/magnesium pyrophosphates were detected in some samples.
Phosphorus availability of sewage sludge-based fertilizers determined by the diffusive gradients in thin films (DGT) technique (2017)
Vogel, Christian ; Sekine, R. ; Steckenmesser, D. ; Lombi, E. ; Steffens, D. ; Adam, Christian
The plant-availability of phosphorus (P) in fertilizers and soil can strongly influence the yield of agricultural crops. However, there are no methods to efficiently and satisfactorily analyze the plant-availability of P in sewage sludge-based P fertilizers except by undertaking time-consuming and complex pot or field experiments. We employed the diffusive gradients in thin films (DGT) technique to quantify the plant P availability of various types of P fertilizers with a novel focus on sewage sludge-based P fertilizers. Mixtures of fertilizer and soil were incubated for 3 weeks at 60% water holding capacity. DGT devices were deployed at the beginning of the incubation and again after 1, 2, and 3 weeks. Two weeks of incubation were sufficient for the formation of plant-available P in the fertilizer/soil mixtures. In a pot experiment, the DGT technique predicted maize (Zea mays L.) biomass yield and P uptake significantly more accurately than standard chemical extraction tests for P fertilizers (e.g., water, citric acid, and neutral ammonium citrate). Therefore, the DGT technique can be recommended as a reliable and robust method to screen the performance of different types of sewage sludge-based P fertilizers for maize cultivation minimizing the need for time-consuming and costly pot or field experiments.
Determination of chromium (VI) in primary and secondary fertilizer and their respective precursors (2017)
Krüger, Oliver ; Fiedler, F. ; Adam, Christian ; Vogel, Christian ; Senz, R.
Hexavalent chromium species (Cr(VI)) are often carcinogenic, of high acute toxicity, highly mobile, and thus pose a severe risk to health and environment. Fertilizers usually contain significant amounts of chromium. Therefore, a reliable analysis of chromium and the fraction of Cr(VI) are crucial for safe use of fertilizers. This problem is expected to increase in the future, since more and more recycled fertilizers emerge due to increasing fertilizer demand and respective supply risks. However, existing analytical methods have been developed for conventional fertilizers and have to be tested whether they are suitable for the new materials. Thus, we performed a wet-chemical extraction for Cr(VI) on several matrices as well as respective quality control experiments including spiking with Cr(III) and Cr(VI)compounds. We found the Cr(VI) amounts to be below 2 mg/kg except for a thermally post-treated sewage sludge ash (SSA) that showed 12.3 mg/kg. The presence of organic matter e.g. in sludge or precipitated struvite caused a reduction of spiked Cr(VI) and thus no satisfying recovery for Quality control. Cr(VI) reduction was also observed for SSA, presumably due to the presence of Fe(II) compounds. Even though the tested procedure can be hampered in some recycled fertilizer matrices, it might be adapted to be applicable also for these complex samples.
Combining diffusive gradients in thin films (DGT) and spectroscopic techniques for the determination of phosphorus species in soils (2019)
Vogel, Christian ; Sekine, R. ; Steckenmesser, D. ; Lombi, E. ; Herzel, Hannes ; Zuin, L. ; Wang, D. ; Felix, R. ; Adam, Christian
A wide range of methods are used to estimate the plant-availability of soil phosphorus (P). Published research has shown that the diffusive gradients in thin films (DGT) technique has a superior correlation to plant-available P in soils compared to standard chemical extraction tests. In order to identify the plantavailable soil P species, we combined DGT with infrared and P K- and L2,3-edge X-ray adsorption near edge structure (XANES) spectroscopy. This was achieved by spectroscopically investigating the dried binding layer of DGT devices after soil deployment. All three spectroscopic methods were able to distinguish between different kinds of phosphates (poly-, trimeta-, pyro- and orthophosphate) on the DGT binding layer. However, infrared spectroscopy was most sensitive to distinguish between different types of adsorbed inorganic and organic phosphates. Furthermore, intermediates of the time-resolved hydrolysis of trimetaphosphate in soil could be analyzed.
Chemical state of mercury and selenium in sewage sludge ash based P-fertilizers (2016)
Vogel, Christian ; Krüger, Oliver ; Herzel, Hannes ; Amidani, L. ; Adam, Christian
Phosphorus-fertilizers from secondary resources such as sewage sludge ash (SSA) will become more important in the future as they could substitute conventional fertilizers based on the nonrenewable resource phosphate rock. Thermochemical approaches were developed which remove heavy metals from SSA prior to its fertilizer application on farmlands. We analyzed the chemical state of mercury and selenium in SSA before and after thermochemical treatment under different conditions for P-fertilizer production by X-ray absorption near edge structure (XANES) spectroscopy. In some incineration plants the mercury loaded carbon adsorber from off-gas cleaning was collected together with the SSA for waste disposal. SSAs from those plants contained mercury mainly bound to carbon/organic material. The other SSAs contained inorganic mercury compounds which are most probably stabilized in the SSA matrix and were thus not evaporated during incineration. During thermochemical treatment, carbon-bound mercury was removed quantitatively. In contrast, a certain immobile fraction of inorganic mercury compounds remained in thermochemically treated SSA, which were not clearly identified. HgSe might be one of the inorganic compounds, which is supported by results of Se K-edge XANES spectroscopy. Furthermore, the chemical state of selenium in the SSAs was very sensitive to the conditions of the thermochemical treatment.
Air and chlorine gas corrosion of different silicon carbides analyzed by nano-Fourier-transform infrared (nano-FTIR) spectroscopy (2018)
Vogel, Christian ; Hermann, P. ; Kästner, B. ; Adamczyk, Burkart ; Hoehl, A. ; Ulm, G. ; Adam, Christian
The present study shows the potential of high-resolution imaging and nano-Fourier-transform infrared (nano-FTIR) spectroscopy for corrosion science. The protective oxidation layers of different chlorine-gas treated silicon carbides (SiCs) were characterized with these techniques. A nitrified SiC showed the highest resistant strength against chlorine corrosion at 1000 °C compared to the other SiCs. Nano-FTIR spectroscopy with a lateral resolution below 40 nm detected differences in the crystallinity of the bulk-SiC and in the transitional region to the protective layer. Furthermore, high-resolution imaging provides deep insight in the interfacial layer between bulk-SiC and the protective oxidation layer on sub-micrometer scale.
Spectroscopic investigation in the mid- and far-infrared regions of phosphorus fertilizers derived from thermochemically treated sewage sludge ash (2011)
Vogel, Christian ; Kohl, Anka ; Adam, Christian
Inorganic phosphorus and nitrogen-phosphorus-potassium (NPK) fertilizers based on phosphates from thermochemically treated sewage sludge ash were analyzed using mid-infrared (mid-IR) and far-infrared (FIR) spectroscopy. The different compounds present in the fertilizers were qualitatively determined with the help of recorded reference spectra of pure substances. Differentiation between various phosphates and other compounds such as sulfates, nitrates, and oxides was possible using combined interpretation of the mid-IR and FIR spectra. The results are in agreement with previous X-ray diffraction (XRD) measurements of the same samples. The main phosphate phases detected were NH4H2PO4, MgHPO4·3H2O, Mg3(PO4)2, Ca5(PO4)5Cl, CaHPO4·2H2O, Ca(H2-PO4)2·H2O, and AlPO4. Furthermore, K2SO4, NH4NO3, Fe2O3, and SiO2 were identified in the IR spectra. However, ammonium and sulfate compounds were only identified in the mid-IR region but were not detectable in the FIR region.
Heavy metal removal from sewage sludge ash analyzed by thermogravimetry (2011)
Vogel, Christian ; Adam, Christian ; Unger, M.
A high temperature (1000 °C) thermochemical process for heavy metal removal from sewage sludge ash via the chloride pathway was investigated by thermogravimetry/differential thermal analysis (TG/DTA). TG and DTA measurements gave information about secession and evaporation of water, HCl, and heavy metal chlorides at different temperatures. Additionally, gaseous water and hydrochloric acid which occurred in the process were detected by an FT-IR detector that was coupled to the TG/DTA-system. Heavy metal chlorides which were also formed in the process cannot be detected by this technique. For that reason the outlet gas of the TG/DTA-system was discharged into washing flasks filled with water for absorption. The washing flasks were replaced in temperature steps of 50 °C and the heavy metal concentrations of the solutions were determined by ICP-OES. The temperature-dependent formation/evaporation of different heavy metal chlorides was analyzed and compared for two different thermochemical processes using magnesium chloride hydrate or calcium chloride hydrate as Cl-donors. In both cases evaporation of Cd, Cu, Pb, and Zn was observed from 600 °C, whereas As, Cr, and Ni remained in the solid state. The results were discussed against the background of thermodynamic calculations.
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