TY - JOUR
A1 - Dombinov, V.
A1 - Herzel, Hannes
A1 - Meiller, M.
A1 - Müller, F.
A1 - Willbold, S.
A1 - Zang, J. W.
A1 - da Fonseca-Zang, W. A.
A1 - Adam, Christian
A1 - Klose, H.
A1 - Poorter, H.
A1 - Jablonowski, N. D.
A1 - Schrey, S. D.
T1 - Sugarcane bagasse ash as fertilizer for soybeans: Effects of added residues on ash composition, mineralogy, phosphorus extractability and plant availability
N2 - Sugarcane bagasse is commonly combusted to generate energy. Unfortunately, recycling strategies rarely consider the resulting ash as a potential fertilizer. To evaluate this recycling strategy for a sustainable circular economy, we characterized bagasse ash as a fertilizer and measured the effects of co-gasification and co-combustion of bagasse with either chicken manure or sewage sludge: on the phosphorus (P) mass fraction, P-extractability, and mineral P phases. Furthermore, we investigated the ashes as fertilizer for soybeans under greenhouse conditions. All methods in combination are reliable indicators helping to assess and predict P availability from ashes to soybeans. The fertilizer efficiency of pure bagasse ash increased with the ash amount supplied to the substrate. Nevertheless, it was not as effective as fertilization with triple-superphosphate and K2SO4, which we attributed to lower P availability. Co-gasification and co-combustion increased the P mass fraction in all bagasse-based ashes, but its extractability and availability to soybeans increased only when co-processed with chicken manure, because it enabled the formation of readily available Ca-alkali phosphates. Therefore, we recommend co-combusting biomass with alkali-rich residues to increase the availability of P from the ash to plants.
KW - Combustion and gasification
KW - Phosphate extractability and availability
KW - X-ray diffraction (XRD)
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-567632
DO - https://doi.org/10.3389/fpls.2022.1041924
SN - 1664-462X
VL - 13
SP - 1
EP - 13
PB - Frontiers Media
CY - Lausanne
AN - OPUS4-56763
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Herzel, Hannes
T1 - Thermochemical P recycling from ash by AshDec ® process
N2 - Klärschlammaschen können eine hohe Phosphatkonzentration aufweisen und stellen damit einen geeigneten Sekundärrohstoff für die Produktion von Phosphatdüngemitteln dar. Bisher wird dieses Potential der Klärschlammaschen für die Phosphor-Rückgewinnung jedoch kaum genutzt, da die in den Aschen enthaltenen Phosphate für Pflanzen kaum verfügbar und die Aschen teilweise mit toxischen Schwermetallen belastet sind.
Im AshDec®-Verfahren wird die Klärschlammaschen im Drehrohrofen im Temperaturbereich 800-1000°C unter Zugabe von Alkali-Additiven (bsp. Na2CO3) thermochemisch behandelt, um ein wirksames und schadstoffarmes Phosphatdüngemittel herzustellen. Aktuell bereitet die Firma Emter GmbH den Bau der ersten großtechnischen AshDec®-Anlage mit einer Kapazität von 30.000 Jahrestonnen Klärschlammasche am Standort ihrer Klärschlammverbrennungsanlage (Altenstadt / Oberbayern) vor. Die erste Ausbaustufe dieser Anlage wird durch das BMBF-Projekt R-Rhenania im Rahmen der Förderinitiative RePhoR begleitet.
T2 - Wastewater, Water and Resource Recovery (Workshop)
CY - Online meeting
DA - 11.04.2022
KW - Phosphorus recovery
KW - Heavy metal removal
KW - Ashdec
PY - 2022
AN - OPUS4-54727
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - THES
A1 - Herzel, Hannes
T1 - Phase reaction during thermochemical treatment of sewage sludge and biomass ashes with alkali compounds to increase nutrient plant availability
N2 - Das Element Phosphor ist für Pflanzen, Tiere und Menschen essenziell. Um die Phosphorversorgung für Pflanzen in der Landwirtschaft zu gewährleisten, werden Phosphordünger eingesetzt. Die Nährstoffe werden hauptsächlich durch Wirtschaftsdünger (Gülle, Jauche, Stallmist) zurückgeführt. Zusätzlich werden in der konventionellen Landwirtschaft mineralische Phosphordünger eingesetzt, die vorwiegend aus dem fossilen Rohstoff Phosphorit gewonnen werden. Um die Abhängigkeit von fossilen Rohstoffen zu reduzieren, sollen nährstoffhaltige Rest- und Abfallstoffe zur Phosphordünger aufbereitet werden. In Abwasserkläranlagen fällt phosphorreicher Klärschlamm als Abfallstoff an. Der größte Anteil des Klärschlammes wird in Steinkohlekraftwerken, Zementwerken oder in Monoklärschlammverbrennungsanlagen verbrannt. Die Klärschlammaschen aus den Monoverbrennungsanlagen enthalten bis zu 12 Gew.-% Phosphor und sind daher für die Düngerherstellung geeignet.
Ein geeignetes Verfahren zur Aufbereitung der Klärschlammaschen ist die thermochemische Behandlung im Drehrohrofen. Mit dem sogenannten AshDec®-Prozess, kann ein Phosphordünger hergestellt werden. Aktuell wird eine großtechnische Anlage in Altenstadt (Bayern) geplant, die im Jahr 2023 den Betrieb aufnehmen soll. Der zentrale Bestandteil ist die Phasenumwandlung von schlecht pflanzenverfügbaren Phosphaten in der Klärschlammasche (vorwiegend das Calciumphosphat Whitlockit und Aluminiumphosphat) zu gut pflanzenverfügbaren Calciumalkaliphosphaten im Produkt. Um dies zu erzielen, werden die Aschen mit Natrium- und/oder Kalium-Verbindungen gemischt und einer thermochemischen Behandlung bei 800-1000 °C zugeführt. Um die Pflanzenverfügbarkeit und Düngewirkung von Phosphaten abschätzen zu können, ist die chemische Extraktionsmethode mit neutraler Ammoniumcitratlösung geeignet.
In der Dissertation werden die (Phosphor-)Phasenreaktionen und die Prozessbedingungen des thermochemischen Verfahrens untersucht, um das Verfahren gezielt zu modifizieren und die Wirtschaftlichkeit zu steigern. Die Zielphasen der thermochemischen Behandlung sind die Calciumalkaliphosphate CaNaPO4 und CaKPO4, und deren Mischphasen Ca(Na,K)PO4, welche in der Publikation 3.1 synthetisiert wurden. Für diese Calciumalkaliphosphate wurden die thermodynamischen Daten der Standardbildungsenthalpie, Standardentropie, Wärmekapazität und die Wärmemenge der Phasenumwandlung bestimmt (Publikation 3.1).
Bei der thermochemischen Behandlung von Klärschlammaschen wurden als Additive Natrium- und Kaliumsulfat bei verschiedenen Temperaturen getestet. Der Einsatz von Kaliumadditiven ist erwünscht, um den Marktwert des Produktes durch die Produktion eines Phosphor-Kalium-Düngers zu erhöhen. Zusätzlich wird eine möglichst geringe Prozesstemperatur angestrebt, bei der die erwünschten Calciumalkaliphosphate gebildet werden.
In den Publikationen 3.2 und 3.3 wird gezeigt, dass für Klärschlammaschen eine komplette Phasenumwandlung zu Calciumnatriumphosphaten ab 875 °C in Laborversuchen (Korundtiegel) mit dem Additiv Natriumsulfat erzielt werden kann. Der Einsatz von Kaliumsulfat erforderte notwendige Reaktionstemperaturen von über 1100 °C. Diese
unterschiedlichen Reaktionstemperaturen hängen mit den Schmelzpunkten von Natriumsulfat (890 °C) und Kaliumsulfat (1070 °C) zusammen. Um Kaliumsulfat in den Prozess bei niedrigen Temperaturen zu integrieren, wurden Natriumsulfat und Kaliumsulfat vor der Behandlung gemischt. Dies führte zu einer Schmelzpunkterniedrigung und resultierte in Reaktionstemperaturen zwischen 900 °C bis 1000 °C für die untersuchten Mischungen von Natrium- und Kaliumsulfat (Publikation 3.3).
Die Zusammensetzung der Calciumalkaliphosphate Ca(Na,K)PO4 war anders als erwartet. Bei der Phasenanalytik stellte sich heraus, dass bei geringem und mittlerem Anteil von Kaliumsulfat im Alkali-Additiv nur Calciumnatriumphosphate mit sehr geringen Kaliumgehalten gebildet wurden. Erst bei einem hohen Anteil von Kaliumsulfat in der Mischung der Alkalisulfate konnten kaliumhaltige Calciumalkaliphosphate nachgewiesen werden (u.a. (Ca0.9Mg0.1)(Na0.6K0.4)PO4). Dieser geringere Einbau von Kalium in die Calciumalkaliphosphate hängt mit den zusätzlich stattfindenden Reaktionen zwischen den Alkalien und den Silikaten zusammen. Es ist bekannt, dass die zugegebenen Alkalisulfate zuerst mit Silikaten und anschließend mit den Phosphaten reagieren. Silikate bauen bevorzugt Kalium ein, deswegen konnten erst kaliumhaltige Phosphate gebildet werden, wenn die Reaktion mit den Silikaten abgeschlossen war. Dies führte zu einem geringeren Kaliumanteil in den gebildeten Phosphaten im Vergleich zum Kaliumanteil der verwendeten Alkaliadditive. Das in Silikaten gebundene Kalium ist wahrscheinlich schlecht für die Pflanzen verfügbar. Dies könnte den Einsatz der produzierten Phosphor-Kalium-Dünger einschränken. Der bevorzugte Kaliumeinbau in Silikaten konnte auch in Kalkulationen mit den thermodynamischen Daten aus der Publikation 3.1 gezeigt werden.
Mittels Phasenanalytik vor und nach der chemischen Extraktion, konnte die Zugehörigkeit zu verschiedenen Modifikationen der Calciumalkaliphosphaten sicher bestimmt werden und eine ungefähre Zusammensetzung dieser Calciumalkaliphosphate abgeschätzt werden. So konnte nachgewiesen werden, dass die Modifikation vom CaNaPO4 ungefähr 10 % Magnesium einbauen kann. Wenn mehr Magnesium eingebaut wird, bildet sich die Phase (Ca,Mg)NaPO4, die eine vergleichbare Struktur wie die bekannte Phase (Ca0.72Mg0.28)NaPO4 aufweist. Dieses magnesiumreiche Calciumnatriumphosphat entstand vermutlich, wenn entweder erhöhte Anteile an Kalium eingebaut wurden (Ca0.8Mg0.2)(Na0.85K0.15)PO4 (Publikation 3.3) oder die Phasenumwandlung vom Calciumphosphat Whitlockit zum Calciumalkaliphosphat CaNaPO4 noch nicht abgeschlossen war (Publikation 3.2). Wenn mehr Kalium eingebaut wird, dann entsteht eine Phase (u.a. (Ca0.9Mg0.1)(Na0.6K0.4)PO4) ähnlich zu den Mischphasen aus der Publikation 3.1.
In den Publikationen 3.4 und 3.5 wurden keine Klärschlammaschen untersucht, sondern Biokohlen aus Modellklärschlämmen (Publikation 3.5) und Biomasseaschen (Publikation 3.4) aus der Vergasung oder Verbrennung einer Mischung aus Zuckerrohrbagasse und Hühnertrockenkot. Die thermochemischen Produkte der Biokohlen bzw. Biomasseaschen enthielten das gewünschte CaNaPO4 und hatten eine hohe Düngewirkung in Pflanzenwachstumsversuchen mit Sojapflanzen bzw. Gräsern.
KW - AshDec
KW - Recycling fertilizer
KW - Calcium alkali phosphate
PY - 2020
SP - 1
EP - 186
CY - Jena
AN - OPUS4-54724
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Herzel, Hannes
A1 - Aydin, Zeynep
A1 - Adam, Christian
T1 - Crystalline phase analysis and phosphorus availability after thermochemical treatment of sewage sludge ash with sodium and potassium sulfates for fertilizer production
N2 - Phosphorus rich sewage sludge ash is a promising source to produce phosphorus recycling fertilizer. However, the low plant availability of phosphorus in these ashes makes a treatment necessary. A thermochemical treatment (800–1000 °C) with alkali additives transforms poorly plant available phosphorus phases to highly plant available calcium alkali Phosphates (Ca,Mg)(Na,K)PO4. In this study, we investigate the use of K2SO4 as additive to produce a phosphorus potassium fertilizer in laboratory-scale experiments (crucible). Pure K2SO4 is not suitable as high reaction temperatures are required due to the high melting point of K2SO4.
To overcome this barrier, we carried out series of experiments with mixtures of K2SO4 and Na2SO4 resulting in a lower economically feasible reaction temperature (900–1000 °C). In this way, the produced phosphorus potassium fertilizers (8.4 wt.% K, 7.6 wt.% P) was highly plant available for phosphorus indicated by complete extractable phosphorus in neutral ammonium citrate solution. The added potassium is, in contrast to sodium, preferably incorporated into silicates instead of phosphorus phases. Thus, the highly extractable phase (Ca,Mg)(Na,K)PO4 in the thermochemical products contain less potassium than expected. This preferred incorporation is confirmed by a pilot-scale trial (rotary kiln) and thermodynamic calculation.
KW - Phosphorus recovery
KW - Recycling fertilizer
KW - Calcium alkali phosphate
KW - Silicate
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-536276
DO - https://doi.org/10.1007/s10163-021-01288-3
SN - 1611-8227
IS - 23
SP - 2242
EP - 2254
PB - Springer
AN - OPUS4-53627
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Herzel, Hannes
A1 - Dombinov, V.
A1 - Vogel, Christian
A1 - Willbold, S.
A1 - Levandowski, G. V.
A1 - Meiller, M.
A1 - Müller, F.
A1 - Zang, J. W.
A1 - da Fonseca-Zang, W. A.
A1 - Jablonowski, N. D.
A1 - Schrey, S. D.
A1 - Adam, Christian
T1 - Soybean Fertilized by P-Phases from Bagasse-Based Materials: P-Extraction Procedures, Diffusive Gradients in Thin Films (DGT), and X-ray Diffraction Analysis (XRD)
N2 - The Brazilian sugarcane industry produced around 173 million tons (Mt) of bagasse in 2018. Bagasse is a by-product of juice extraction for ethanol and sugar production and is combusted in order to generate power, producing up to 10 Mt of ash per year. This ash contains various concentrations of plant nutrients, which allow the ash to be used as a crop fertilizer. However, the concentration and extractability of phosphorus (P), an essential plant nutrient, are low in bagasse ash. To increase the P content, we co-gasified and co-combusted bagasse with P-rich chicken manure. The resulting ash was thermochemically post-treated with alkali additives (Na2SO4 and K2SO4) to increase the availability of P to plants. We aimed to: (i) investigate the effect of thermochemical post-treatment of co-gasification residue and co-combustion ash on P availability to soybeans, (ii) explore the potential of chemical extraction methods (citric acid, neutral ammonium citrate, formic acid, and Mehlich-I) and diffusive gradients in thin films (DGT) to predict the availability of P to soybeans, and (iii) identify the responsible P-phases using X-ray diffraction . We evaluated P availability to soybeans growing in Brazilian Oxisol soil in two independent greenhouse pot experiments. The positive effect of thermochemical treatment on P availability from gasification residue was confirmed through the observation of increased P uptake and biomass in soybean plants. These findings were confirmed by chemical extraction methods and DGT. The gasification residue contained whitlockite as its main P-bearing phase. Thermochemical post-treatment converted whitlockite into highly soluble CaNaPO4. In contrast, co-combustion ash already contained highly soluble Ca(Na,K)PO4 as its main P-bearing phase, making thermochemical post-treatment unnecessary for increasing P availability. In conclusion, increased extractability and availability of P for soybeans were closely connected to the formation of calcium alkali phosphate. Our findings indicate that this combined methodology allows for the prediction of P-fertilization effects of ash.
KW - Sugar cane bagasse
KW - Chicken manure ash
KW - Thermochemical treatment
KW - Nutrient
KW - Plant availability
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509735
DO - https://doi.org/10.3390/agronomy10060895
VL - 10
SP - 895
EP - 6
PB - MDPI
AN - OPUS4-50973
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Herzel, Hannes
A1 - Grevel, K.-D.
A1 - Emmerling, Franziska
A1 - Dachs, E.
A1 - Benisek, A.
A1 - Adam, Christian
A1 - Majzlan, J.
T1 - Thermodynamic properties of calcium alkali phosphates Ca(Na,K)PO4
N2 - Calcium alkali phosphates Ca(Na,K)PO4 are main constituents of bioceramics and thermochemically produced phosphorus fertilizers because of their bioavailability. Sparse thermodynamic data are available for the endmembers CaNaPO4 and CaKPO4. In this work, the missing data were determined for the low-temperature phase modifications of the endmembers CaNaPO4 and CaKPO4 and three intermediate Ca(Na,K)PO4 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 b-CaNaPO4 to potassium endmember b0-CaKPO4.
Thermodynamic functions are calculated up to 1400 K for endmembers and the sodium-rich intermediate phase b-Ca(Na0.93K0.07)PO4. Functions above 640 K are extrapolated because of the phase transition from low- to high-temperature phase. Impurities in the synthesized intermediate phases c-Ca(Na0.4K0.6)PO4 and c-Ca Na0.35K0.65)PO4 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.
KW - Formation enthalpy
KW - Heat capacity
KW - Phase transformation
KW - Bioceramics
KW - Phosphorus fertilizer
KW - Entropy
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-507640
DO - https://doi.org/10.1007/s10853-020-04615-5
VL - 55
SP - 8477
EP - 8490
PB - Springer
AN - OPUS4-50764
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Herzel, Hannes
A1 - Stemann, J.
A1 - Simon, Sebastian
A1 - Adam, Christian
T1 - Comparison of thermochemical treatment of sewage sludge ash with sodium sulphate in laboratory-scale and pilot-scale experiments
N2 - There is an ongoing debate on European scale concerning the criticality of phosphorus. In Switzerland and Germany, phosphorus recovery from phosphorus-rich waste streams will become obligatory. Sewage sludge ash is rich in phosphorus and may become an important secondary feedstock. Thermochemical treatment of sewage sludge ash with sodium sulphate under reducing conditions was shown to remove heavy metals from the solid product and produce the fully plant available crystalline phase CaNaPO4. Pilot-scale experiments in a rotary kiln were carried out at temperatures between 750 and 1000 °C and were compared to laboratory-scale experiments with crucibles. Process upscaling was successfully demonstrated but a series of differences were noticed: In comparison to laboratory-scale, solubility of phosphorus in samples from pilot-scale experiments was lower at all chosen treatment temperatures because of shorter retention time and incomplete decomposition of sodium sulphate. X-ray diffraction analysis revealed remaining phase fractions of whitlockite (Ca3-x(Mg,Fe)x(PO4)2) and sodium sulphate from the starting materials in products and thus indicated incomplete reaction. In contrast to the results of laboratory-scale experiments, the crystalline phase CaNaPO4 was clearly absent in the products from the rotary kiln but instead a Mg-bearing phase (Ca,Mg)NaPO4 was formed. Laboratory-scale experiments confirmed (Ca,Mg)NaPO4 is an intermediate phase between whitlockite and CaNaPO4. However, both crystalline phases are characterized by high plant availability. It was shown that heavy metal removal increased at higher temperatures whereas solubility and thus plant availability of phosphorus already reached its maxima at temperatures of 950 °C in pilot-scale and 875 °C in laboratory-scale experiments.
KW - Crystalline phase identification
KW - Heavy metal removal
KW - Phosphorus availability
KW - Process upscaling
KW - Recovery
KW - Rhenanite
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-524084
DO - https://doi.org/10.1007/s13762-021-03252-y
VL - 19
IS - 3
SP - 1997
EP - 2006
PB - Springer
AN - OPUS4-52408
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Leers, K.
A1 - Arnold, U.
A1 - Herzel, Hannes
A1 - Adam, Christian
A1 - Burkhardt, J.
T1 - Thermochemically Treated Sewage Sludge Ash From Pilot-Scale Production as P-Fertilizer for Spring Wheat and Maize in Different Soil Conditions
N2 - Background
P-fertilizers made from sewage sludge ash (SSA) may be suitable substitutes for rock phosphate (RP)-based fertilizers and contribute to sustainable use of waste. In this context, the thermochemical AshDec treatment of SSA (TC-SSA) has been continuously improved and has emerged as a possible method to produce plant-available and low-pollutant P-fertilizers. Aim Evaluation of the P-fertilizer efficacy of TC-SSA produced in pilot trials in vegetation experiments with different plants, soils, and fertilizer doses.
Methods
TC-SSA was tested in pot experiments for spring wheat and maize on different soils and at two doses (0.2 and 0.4 g fertilizer P pot−1) and is compared to untreated SSA (USSA), RP, Struvite, triple superphosphate (TSP), and a control without P-fertilization (Zero P). Pot experiments are complemented by an analysis of fertilizer P-solubility.
Results
P-solubility of SSA with different extraction methods increased due to the thermochemical treatment, whereas the water-insoluble property remained. In contrast to RP or USSA, TC-SSA enriched calcium–acetate–lactate extractable soil P to the same extent as TSP. Plant biomass and P-uptake increased with TC-SSA compared to Zero P, RP, and USSA and were in most cases equal to TSP fertilization under different soil conditions. In contrast, the effects of RP and USSA varied among soils but, mostly, did not exceed plant biomass and P-uptake of the unfertilized control.
Conclusion
TC-SSA has an increased fertilizer efficacy compared to USSA and is an effective P-fertilizer for spring wheat and maize in different soil conditions.
KW - Phosphorus
KW - Fertilizer
KW - Thermochemical
KW - Maize
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648251
DO - https://doi.org/10.1002/jpln.70035
SN - 1522-2624
VL - 189
IS - 1
SP - 81
EP - 93
PB - Wiley-VCH
AN - OPUS4-64825
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Steckenmesser, D.
A1 - Vogel, Christian
A1 - Herzel, Hannes
A1 - Félix, R.
A1 - Adam, Christian
A1 - Steffens, D.
T1 - Thermal treatment of sewage sludge for phosphorus fertilizer production: a model experiment
N2 - Phosphorus (P) resource availability and quality is declining and recycling P-fertilizers from waste materials are becoming increasingly important. One important secondary P resource is sewage sludge (SSL) where P is often bound as aluminum phosphate (Al-P), iron phosphate (Fe-P) and polyphosphate (poly-P), respectively. Thermal treatment in different ways is a promising way in P recycling to produce highly plant-available P-fertilizers. To investigate mechanisms behind transformation of hardly available P-species toward plant-available P forms we treated a model SSL containing different kinds of defined P sources by low-temperature conversion (LTC) at 500 °C and subsequent thermochemical treatment of the LTC product with Na additives (TCT) at 950 °C, respectively. Pot experiments with ryegrass were carried out to determine the plant availability of P of the different treatments. The poly-P (here pyrophosphates) based fertilizers had a very high plant availability after both thermal treatments. During LTC treatment the plant availability of the Fe-P and Al-P variants increased because of the Formation of Fe(II) phosphates and/or pyro-/polyphosphates. Especially the formation of Al-polyphosphate shows a high plant availability. The subsequent TCT further increased strongly the plant availability of the Fe-P variants because of the formation of highly plant-available CaNaPO4. Thus, a direct TCT without prior LTC probably also produce CaNaPO4 and is recommended for Fe-P based SSL. However, a molar Ca/P ratio of � 1 in the fertilizer is favorable for CaNaPO4 formation. Thus, the knowledge on the source of primary P in SSL is essential for choosing the accurate thermal treatment method to produce highly plant-available P-fertilizers from SSL.
KW - Phosphorus
KW - Sewage sludge
KW - X-ray diffraction
KW - X-ray absorption near-edge structure (XANES) spectroscopy
KW - Fertilizer
PY - 2021
DO - https://doi.org/10.1080/01904167.2021.1994595
SN - 0190-4167
VL - 45
IS - 8
SP - 1123
EP - 1133
PB - Taylor & Francis Online
AN - OPUS4-53755
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Vogel, Christian
A1 - Helfenstein, J.
A1 - Massey, M.
A1 - Sekine, R.
A1 - Kretzschmar, R.
A1 - Beiping, L.
A1 - Peter, T.
A1 - Chadwick, O.
A1 - Tamburini, F.
A1 - Rivard, C.
A1 - Herzel, Hannes
A1 - Adam, Christian
A1 - Pradas del Real, A.
A1 - Castillo-Michel, H.
A1 - Zuin, L.
A1 - Wang, D.
A1 - Félix, R.
A1 - Lassalle-Kaiser, B.
A1 - Frossard, E.
T1 - Microspectroscopy reveals dust-derived apatite grains in acidic, highly-weathered Hawaiian soils
N2 - Dust deposition is an important source of phosphorus (P) to many ecosystems. However, there is little evidence of dust-derived P-containing minerals in soils. Here we studied P forms along a well-described climatic Gradient on Hawaii, which is also a dust deposition gradient. Soil mineralogy and soil P forms from six sites along the climatic gradient were analyzed with bulk (X-ray diffraction and P K-edge X-ray absorption near edge structure) and microscale (X-ray fluorescence, P K-edge X-ray absorption near edge structure, and Raman) analysis methods. In the wettest soils, apatite grains ranging from 5 to 30 μm in size were co-located at the micro-scale with quartz, a known continental dust indicator suggesting recent atmospheric deposition. In addition to co-location with quartz, further evidence of dust-derived P included backward trajectory modeling indicating that dust particles could be brought to Hawaii from the major global dust-loading areas in central Asia and northern Africa. Although it is not certain whether the individual observed apatite grains were derived from long-distance transport of dust, or from local dust sources such as volcanic ash or windblown fertilizer, these observations offer direct evidence that P-containing minerals have reached surface layers of highly-weathered grassland soils through atmospheric deposition.
KW - Phosphorus
KW - soil
KW - microspectroscopy
KW - Raman spectroscopy
KW - XANES spectroscopy
KW - x-ray diffraction
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-511522
DO - https://doi.org/10.1016/j.geoderma.2020.114681
SN - 0166-0918
SN - 1872-6259
VL - 381
SP - 114681-1
EP - 114681-11
PB - Elsevier
CY - Amsterdam
AN - OPUS4-51152
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -