Co-pyrolysis of sewage sludge/cotton stalks with K2CO3 for biochar production : Improved biochar porosity and reduced heavy metal leaching
Copyright © 2021 Elsevier Ltd. All rights reserved.
| Veröffentlicht in: | Waste management (New York, N.Y.). - 1999. - 135(2021) vom: 11. Nov., Seite 199-207 |
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| Weitere Verfasser: | , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2021
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| Zugriff auf das übergeordnete Werk: | Waste management (New York, N.Y.) |
| Schlagworte: | Journal Article Biochar Co-pyrolysis Cotton stalks K(2)CO(3) activation Sewage sludge Metals, Heavy Sewage biochar Charcoal |
| Zusammenfassung: | Copyright © 2021 Elsevier Ltd. All rights reserved. The co-pyrolysis of sewage sludge and biomass is considered a promising technique for reducing the volume of sewage sludge, adding value, and decreasing the risk associated with this waste. In this study, sewage sludge and cotton stalks were pyrolyzed together with different amounts of K2CO3 to evaluate the potential of chemical activation using K2CO3 for improving the porosity of the biochar formed and immobilizing the heavy metals present in it. It was found that K2CO3 activation effectively improved the pore structure and increased the aromaticity of the biochar. Moreover, K2CO3 activation transformed the heavy metals (Cu, Zn, Pb, Ni, Cr, and Cd) into more stable forms (oxidizable and residual fractions). The activation effect became more pronounced with increasing amount of added K2CO3, eventually resulting in a significant reduction in the mobility and bioavailability of the heavy metals in the biochar. Further analysis revealed that, during the co-pyrolysis process, K2CO3 activation resulted in a reductive atmosphere, increased the alkalinity of the biochar, and led to the formation CaO, CaCO3, and aluminosilicates, which aided the immobilization of the heavy metals. K2CO3 activation also effectively reduced the leachability, and thus, the environmental risks of the heavy metals. Thus, K2CO3 activation can improve the porosity of the biochar derived from sewage sludge/cotton stalks and aid the immobilization of the heavy metals in it |
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| Beschreibung: | Date Completed 19.10.2021 Date Revised 19.10.2021 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1879-2456 |
| DOI: | 10.1016/j.wasman.2021.08.042 |