Journalartikel

Jahr der Veröffentlichung: 2022

Seiten: 1123-1133

Zeitschrift: Journal of Plant Nutrition

Bandnummer: 45

Heftnummer: 8

ISSN: 0190-4167

eISSN: 1532-4087

DOI Link: https://doi.org/10.1080/01904167.2021.1994595

Verlag: Taylor and Francis Group

Abstract: 
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 degrees C and subsequent thermochemical treatment of the LTC product with Na additives (TCT) at 950 degrees 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 similar to 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.

Harvard-Zitierstil: Steckenmesser, D., Vogel, C., Herzel, H., Felix, R., Adam, C. and Steffens, D. (2022) Thermal treatment of sewage sludge for phosphorus fertilizer production: a model experiment, Journal of Plant Nutrition, 45(8), pp. 1123-1133. https://doi.org/10.1080/01904167.2021.1994595

APA-Zitierstil: Steckenmesser, D., Vogel, C., Herzel, H., Felix, R., Adam, C., & Steffens, D. (2022). Thermal treatment of sewage sludge for phosphorus fertilizer production: a model experiment. Journal of Plant Nutrition. 45(8), 1123-1133. https://doi.org/10.1080/01904167.2021.1994595