Sequential electrodialytic recovery of phosphorus from low-temperature gasification ashes of chemically precipitated sewage sludge
Copyright © 2016 Elsevier Ltd. All rights reserved.
Veröffentlicht in: | Waste management (New York, N.Y.). - 1999. - 60(2017) vom: 05. Feb., Seite 211-218 |
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1. Verfasser: | |
Weitere Verfasser: | , , , |
Format: | Online-Aufsatz |
Sprache: | English |
Veröffentlicht: |
2017
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Zugriff auf das übergeordnete Werk: | Waste management (New York, N.Y.) |
Schlagworte: | Journal Article Electrodialysis Heavy metals Iron phosphates Low-temperature gasification Phosphorus Sewage sludge ash Aluminum Compounds Ferric Compounds Phosphates mehr... |
Zusammenfassung: | Copyright © 2016 Elsevier Ltd. All rights reserved. Phosphorus recycling from secondary materials like sewage sludge ashes offers an alternative to mining of phosphates from primary resources and a mean to counteract the current phosphorous rock depletion concern. A separation of P from the bulk ash is normally required, due to its low plant availability and the presence of heavy metals. Previously, more than 80% of P was recovered from incineration sewage sludge ashes using a two-compartment electrodialytic cell. In contrast, the recovery was below 30% for ashes from low-temperature gasification using the same setup. The low recovery was due to a high presence of Al- and Fe(III)-P bindings. In the present study, an electrodialytic process combining sequentially a pair of two-compartment cells allowed a recovery of up to 70% of phosphorus from these ashes. The use of a second cell, where the ash was suspended in an alkaline solution, allowed the P solubilisation from aluminium and ferric phosphates. In addition, P was separated from most metals as they became insoluble under the prevailing chemical environment. The obtained ratio of Al, Fe, Mg and most heavy metals to P was comparable to wet process phosphoric acid. Therefore, this sequential process was found to be suitable to recycle P and potentially use it in the production of common fertilizers like diammonium phosphate |
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Beschreibung: | Date Completed 21.06.2017 Date Revised 21.06.2017 published: Print-Electronic Citation Status MEDLINE |
ISSN: | 1879-2456 |
DOI: | 10.1016/j.wasman.2016.11.030 |