Transformation and stabilization of heavy metals during pyrolysis of organic and inorganic-dominated sewage sludges and their mechanisms
Copyright © 2022 Elsevier Ltd. All rights reserved.
| Veröffentlicht in: | Waste management (New York, N.Y.). - 1999. - 150(2022) vom: 01. Aug., Seite 57-65 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2022
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| Zugriff auf das übergeordnete Werk: | Waste management (New York, N.Y.) |
| Schlagworte: | Journal Article Heavy metals Pyrolysis Sewage sludge Stabilization Transformation Metals, Heavy Sewage Soil Charcoal mehr... |
| Zusammenfassung: | Copyright © 2022 Elsevier Ltd. All rights reserved. Improperdisposal of sludge will release heavy metals contained in sludge into soils or waters which could further move through the food chain, posing a risk to human health. Understanding the transformation and stabilization of heavy metals (HMs) during pyrolysis is of great value for safe disposal of sludge. Herein, municipal sewage sludge (MSS, organic-dominated) and pharmacy sludge (PS, inorganic-dominated) were pyrolyzed to investigate the effects of organic and inorganic components and temperature on the stabilization of HMs in sludges. The results showed that pyrolysis can promote the transition of HMs from mobile fractions to stable fractions. Compared to MSS and PS, the potential ecological risk index of biochar derived from MSS and PS decreased by 95.51% and 85.05%, respectively, after pyrolysis at 800 °C. The stabilization of HMs in MSS was mainly due to the complexation reactions between metals and amide functional groups (-CO-NH-) during pyrolysis. Moreover, the mechanism of HMs stabilization in PS lied in the formation of a stable crystal-structure such as copper iron oxide (Cu6Fe3O7) and copper iron phosphate (Cu2Fe5(PO4)6, Cu3Fe4(PO4)6) with iron-containing minerals after high-temperature pyrolysis. The results of this study indicated that the organic and inorganic components of sludge play different roles in the stabilization and transformation of HMs during pyrolysis, which provided a scientific basis for the ecotoxicity reduction of HMs and safe disposal of sludge |
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| Beschreibung: | Date Completed 15.08.2022 Date Revised 15.08.2022 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1879-2456 |
| DOI: | 10.1016/j.wasman.2022.06.023 |