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Christian Adam - One of the best experts on this subject based on the ideXlab platform.

  • Chromium (VI) in Phosphorus Fertilizers determined with the diffusive gradients in thin-films (DGT) technique
    Environmental Science and Pollution Research, 2020
    Co-Authors: Christian Vogel, Marie C. Hoffmann, Oliver Krüger, Vadim Murzin, Wolfgang Caliebe, Christian Adam
    Abstract:

    Phosphorus (P) Fertilizers from secondary resources became increasingly important in the last years. However, these novel P-Fertilizers can also contain toxic pollutants such as chromium in its hexavalent state (Cr(VI)). This hazardous form of chromium is therefore regulated with low limit values for agricultural products even though the correct determination of Cr(VI) in these Fertilizers may be hampered by redox processes, leading to false results. Thus, we applied the novel diffusive gradients in thin-films (DGT) technique for Cr(VI) in Fertilizers and compared the results with the standard wet chemical extraction method (German norm DIN EN 15192) and Cr K-edge X-ray absorption near-edge structure (XANES) spectroscopy. We determined an overall good correlation between the wet chemical extraction and the DGT method. DGT was very sensitive and for most tested materials selective for the analysis of Cr(VI) in P-Fertilizers. However, hardly soluble Cr(VI) compounds cannot be detected with the DGT method since only mobile Cr(VI) is analyzed. Furthermore, Cr K-edge XANES spectroscopy showed that the DGT binding layer also adsorbs small amounts of mobile Cr(III) so that Cr(VI) values are overestimated. Since certain types of the P-Fertilizers contain mobile Cr(III) or partly immobile Cr(VI), it is necessary to optimize the DGT binding layers to avoid aforementioned over- or underestimation. Furthermore, our investigations showed that the Cr K-edge XANES spectroscopy technique is unsuitable to determine small amounts of Cr(VI) in Fertilizers (below approx. 1% of Cr(VI) in relation to total Cr).

  • Thermodynamic properties of calcium alkali phosphates Ca(Na,K)PO_4
    Journal of Materials Science, 2020
    Co-Authors: Hannes Herzel, Christian Adam, Klaus-dieter Grevel, Franziska Emmerling, Edgar Dachs, Artur Benisek, Juraj Majzlan
    Abstract:

    Calcium alkali phosphates Ca(Na,K)PO_4 are main constituents of bioceramics and thermochemically produced Phosphorus Fertilizers because of their bioavailability. Sparse thermodynamic data are available for the endmembers CaNaPO_4 and CaKPO_4. In this work, the missing data were determined for the low-temperature phase modifications of the endmembers CaNaPO_4 and CaKPO_4 and three intermediate Ca(Na,K)PO_4 compositions. Standard enthalpy of formation ranges from − 2018.3 ± 2.2 kJ mol^−1 to − 2030.5 ± 2.1 kJ mol^−1 and standard entropy from 137.2 ± 1.0 J mol^−1 K^−1 to 148.6 ± 1.0 J mol^−1 K^−1 from sodium endmember β-CaNaPO_4 to potassium endmember β′-CaKPO_4. Thermodynamic functions are calculated up to 1400 K for endmembers and the sodium-rich intermediate phase β-Ca(Na_0.93K_0.07)PO_4. Functions above 640 K are extrapolated because of the phase transition from low- to high-temperature phase. Impurities in the synthesized intermediate phases γ-Ca(Na_0.4K_0.6)PO_4 and γ-Ca(Na_0.35K_0.65)PO_4 and one additional phase transition around 500 K impeded the determination of high-temperature thermodynamic functions. In general, data for phase transition temperatures agree with the previously reported phase diagrams.

  • chemical state of chromium sulfur and iron in sewage sludge ash based Phosphorus Fertilizers
    ACS Sustainable Chemistry & Engineering, 2015
    Co-Authors: Christian Vogel, Martin Radtke, Uwe Reinholz, Franz Schafers, Christian Adam
    Abstract:

    As an essential element of all life forms, Phosphorus (P) is vital to the fertilizer industry. With decreasing quantity and quality of phosphate rock resources, recycling P-Fertilizers from wastewater is of increasing interest. The P-fertilizer products of a recently developed thermochemical process for P recovery from sewage sludge ash (SSA) were investigated by chromium, sulfur, and iron K-edge X-ray near-edge structure (XANES) spectroscopy. This paper focuses the formation and prevention of toxic chromium(VI) and toxic sulfides during the thermochemical processes. Reducing conditions prevent the oxidation of chromium(III) in the SSA to toxic chromium(VI). Sulfides formed under the reducing conditions are nontoxic iron sulfides. Hematite (Fe2O3) present in the SSA is reduced to magnetite (Fe3O4). A gentle post-treatment at 400 °C under oxidizing conditions converts the iron sulfides into plant-available iron sulfates. This oxidative post-treatment does not form undesired chromium(VI) compounds.

  • spectroscopic investigation in the mid and far infrared regions of Phosphorus Fertilizers derived from thermochemically treated sewage sludge ash
    Applied Spectroscopy, 2011
    Co-Authors: Christian Vogel, Anka Kohl, Christian Adam
    Abstract:

    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.

Muhammad Farooq Qayyum - One of the best experts on this subject based on the ideXlab platform.

  • co composts of sewage sludge farm manure and rock phosphate can substitute Phosphorus Fertilizers in rice wheat cropping system
    Journal of Environmental Management, 2020
    Co-Authors: Rabia Abdur Rehman, Muhammad Farooq Qayyum
    Abstract:

    Abstract In the present study, various co-composts of sewage sludge (SS), farm manure (FM) and rock phosphate (RP) were prepared and their influence on Phosphorus (P) uptake, soil P restoration and growth of rice crop and residual effect on wheat crop were investigated. The treatments comprised of T1 (control, no amendment), T2 (452 kg Nitrophos ha−1, T3 (724 kg SS50:FM50 ha-1), T4 (594 kg SS100:FM0 ha−1), T5 (728 kg SS25:FM25:RP50 ha−1), T6 (726 kg SS5O:FM25:RP25 ha-1), T7 (508 kg SS75:FM0:RP25 ha−1), and T8 (546 kg SS50:FM0:RP50 ha−1). The post-experimental soil samples were analyzed for pH, EC, OM, Olsen's P. The plant samples (grains and straw of both crops) were analyzed for concentrations of P, and heavy metals. The P adsorption by post-wheat composts-amended soil was tested through Langmuir, and Freundlich adsorption isotherms. The investigated parameters (biomass, grain and straw yield, plant height and P concentrations in plant parts) were significantly increased in all composts as compared to the control treatment. The P uptake by the plants was higher in compost treatments as compared to the control and NP that shows long-term residual effect of applied composts. The maximum grain yield (1.63 Mg ha−1) was obtained in T5 followed by T6 (1.52 Mg ha−1). The P concentration in rice grains were recorded in the trend as T8 (2.55%) > T6 (2.24%) > T4 (1.92%) = T3 (1.88%) > T7 (1.62%). It is evident that the combined application of FM (25%) and RP (50%) enhanced the effect of SS (25%) in terms of P bioavailability and yield parameters and can be effectively used as P fertilizer.

Christian Vogel - One of the best experts on this subject based on the ideXlab platform.

  • Chromium (VI) in Phosphorus Fertilizers determined with the diffusive gradients in thin-films (DGT) technique
    Environmental Science and Pollution Research, 2020
    Co-Authors: Christian Vogel, Marie C. Hoffmann, Oliver Krüger, Vadim Murzin, Wolfgang Caliebe, Christian Adam
    Abstract:

    Phosphorus (P) Fertilizers from secondary resources became increasingly important in the last years. However, these novel P-Fertilizers can also contain toxic pollutants such as chromium in its hexavalent state (Cr(VI)). This hazardous form of chromium is therefore regulated with low limit values for agricultural products even though the correct determination of Cr(VI) in these Fertilizers may be hampered by redox processes, leading to false results. Thus, we applied the novel diffusive gradients in thin-films (DGT) technique for Cr(VI) in Fertilizers and compared the results with the standard wet chemical extraction method (German norm DIN EN 15192) and Cr K-edge X-ray absorption near-edge structure (XANES) spectroscopy. We determined an overall good correlation between the wet chemical extraction and the DGT method. DGT was very sensitive and for most tested materials selective for the analysis of Cr(VI) in P-Fertilizers. However, hardly soluble Cr(VI) compounds cannot be detected with the DGT method since only mobile Cr(VI) is analyzed. Furthermore, Cr K-edge XANES spectroscopy showed that the DGT binding layer also adsorbs small amounts of mobile Cr(III) so that Cr(VI) values are overestimated. Since certain types of the P-Fertilizers contain mobile Cr(III) or partly immobile Cr(VI), it is necessary to optimize the DGT binding layers to avoid aforementioned over- or underestimation. Furthermore, our investigations showed that the Cr K-edge XANES spectroscopy technique is unsuitable to determine small amounts of Cr(VI) in Fertilizers (below approx. 1% of Cr(VI) in relation to total Cr).

  • Medium-scale Plant Experiment of Sewage Sludge-based Phosphorus Fertilizers from Large-scale Thermal Processing
    Communications in Soil Science and Plant Analysis, 2019
    Co-Authors: Daniel Steckenmesser, Christian Vogel, Diedrich Steffens
    Abstract:

    ABSTRACTPhosphorus (P) recycling from sewage sludge for agricultural needs has to meet requirements for agricultural implementation, such as short and long-term P-plant-availability under field con...

  • chemical state of chromium sulfur and iron in sewage sludge ash based Phosphorus Fertilizers
    ACS Sustainable Chemistry & Engineering, 2015
    Co-Authors: Christian Vogel, Martin Radtke, Uwe Reinholz, Franz Schafers, Christian Adam
    Abstract:

    As an essential element of all life forms, Phosphorus (P) is vital to the fertilizer industry. With decreasing quantity and quality of phosphate rock resources, recycling P-Fertilizers from wastewater is of increasing interest. The P-fertilizer products of a recently developed thermochemical process for P recovery from sewage sludge ash (SSA) were investigated by chromium, sulfur, and iron K-edge X-ray near-edge structure (XANES) spectroscopy. This paper focuses the formation and prevention of toxic chromium(VI) and toxic sulfides during the thermochemical processes. Reducing conditions prevent the oxidation of chromium(III) in the SSA to toxic chromium(VI). Sulfides formed under the reducing conditions are nontoxic iron sulfides. Hematite (Fe2O3) present in the SSA is reduced to magnetite (Fe3O4). A gentle post-treatment at 400 °C under oxidizing conditions converts the iron sulfides into plant-available iron sulfates. This oxidative post-treatment does not form undesired chromium(VI) compounds.

  • spectroscopic investigation in the mid and far infrared regions of Phosphorus Fertilizers derived from thermochemically treated sewage sludge ash
    Applied Spectroscopy, 2011
    Co-Authors: Christian Vogel, Anka Kohl, Christian Adam
    Abstract:

    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.

Rabia Abdur Rehman - One of the best experts on this subject based on the ideXlab platform.

  • co composts of sewage sludge farm manure and rock phosphate can substitute Phosphorus Fertilizers in rice wheat cropping system
    Journal of Environmental Management, 2020
    Co-Authors: Rabia Abdur Rehman, Muhammad Farooq Qayyum
    Abstract:

    Abstract In the present study, various co-composts of sewage sludge (SS), farm manure (FM) and rock phosphate (RP) were prepared and their influence on Phosphorus (P) uptake, soil P restoration and growth of rice crop and residual effect on wheat crop were investigated. The treatments comprised of T1 (control, no amendment), T2 (452 kg Nitrophos ha−1, T3 (724 kg SS50:FM50 ha-1), T4 (594 kg SS100:FM0 ha−1), T5 (728 kg SS25:FM25:RP50 ha−1), T6 (726 kg SS5O:FM25:RP25 ha-1), T7 (508 kg SS75:FM0:RP25 ha−1), and T8 (546 kg SS50:FM0:RP50 ha−1). The post-experimental soil samples were analyzed for pH, EC, OM, Olsen's P. The plant samples (grains and straw of both crops) were analyzed for concentrations of P, and heavy metals. The P adsorption by post-wheat composts-amended soil was tested through Langmuir, and Freundlich adsorption isotherms. The investigated parameters (biomass, grain and straw yield, plant height and P concentrations in plant parts) were significantly increased in all composts as compared to the control treatment. The P uptake by the plants was higher in compost treatments as compared to the control and NP that shows long-term residual effect of applied composts. The maximum grain yield (1.63 Mg ha−1) was obtained in T5 followed by T6 (1.52 Mg ha−1). The P concentration in rice grains were recorded in the trend as T8 (2.55%) > T6 (2.24%) > T4 (1.92%) = T3 (1.88%) > T7 (1.62%). It is evident that the combined application of FM (25%) and RP (50%) enhanced the effect of SS (25%) in terms of P bioavailability and yield parameters and can be effectively used as P fertilizer.

Sayed Roholla Mousavi - One of the best experts on this subject based on the ideXlab platform.

  • effect of bio phosphate and chemical Phosphorus fertilizer accompanied with foliar application of micronutrients on yield quality and Phosphorus and zinc concentration of maize
    The Journal of Agricultural Science, 2011
    Co-Authors: Mohammad Galavi, Khatoon Yosefi, Mahmod Ramrodi, Sayed Roholla Mousavi
    Abstract:

    Field experiment was conducted at Kerman Agricultural and Natural Resources Research Centre (Iran) during 2008-2009 to evaluate the effect of bio-fertilizer, Phosphorus and foliar application of micronutrients on dry matter accumulation, yield, and Phosphorus and zinc concentration of maize (Zea mays L.). A split plot experiment based on randomized complete blocks design (RCBD) with four replications was followed in the study. The micronutrients foliar application in two levels (foliar application and non foliar application) were the main plots, and four levels of phosphate (T1: 0 (no fertilizer), T2: 100 kg ha-1 P2O5, T3: 100g bio-phosphate, T4: 100g bio-phosphate with 50 kg ha-1 P2O5) as the sub plots. Results showed that micronutrients foliar application and biological and chemical Phosphorus Fertilizers had a significant influence on dry matter accumulation. The maximum dry matter accumulation was obtained by applying 50 kg/ha P2O5 plus bio-fertilizer. Grain yield, 1000-seed weight and protein content of grain were significantly affected by micronutrients and Phosphorus Fertilizers treatments. Micronutrients foliar application and Phosphorus Fertilizers interaction had no significantly effect on grain yield, 1000-seed weight and grain protein content. Grain Phosphorus and zinc concentration where significantly increased by application of micronutrients and Phosphorus Fertilizers.