Ultrasound-enhanced electrokinetic remediation for removal of Zn, Pb, Cu and Cd in municipal solid waste incineration fly ashes
Copyright © 2018 Elsevier Ltd. All rights reserved.
| Veröffentlicht in: | Waste management (New York, N.Y.). - 1999. - 75(2018) vom: 15. Mai, Seite 226-235 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2018
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| Zugriff auf das übergeordnete Werk: | Waste management (New York, N.Y.) |
| Schlagworte: | Journal Article Electrokinetic Heavy metals Low-frequency ultrasound MSWI fly ashes Remedial efficiency Coal Ash Metals, Heavy Particulate Matter Solid Waste mehr... |
| Zusammenfassung: | Copyright © 2018 Elsevier Ltd. All rights reserved. Low-frequency ultrasound generated by a transducer was investigated to activate the raw municipal solid waste incineration (MSWI) fly ashes in the electrokinetic process, aiming at enhancing heavy metal (HM) removal and achieving better remedial efficacy. The maximum removal efficiencies of 69.84%, 64.24%, 67.74% and 59.93% were obtained in the orthogonal tests of ultrasonication for Zn, Pb, Cu and Cd, respectively. The acoustic time of 30 min and controlling temperature of 45 °C in the operating parameters were quantitatively determined to optimize the ultrasonication of the MSWI fly ash matrices. The changes of acoustic time had a significant effect on the extraction efficiencies of all the four heavy metal elements in the sonication optimal experiments. The longer running time was preferred for the pretreatment of the fly ashes in according to the marginal mean removal results. The voltage gradient of 2 V/cm was most likely to improve the removals of four HMs during the electrokinetics in the range of 0.5-2 V/cm. The synergetic application of acidification and ultrasonication for the media treatment was demonstrated to be most effective in enhancing the remedial efficiencies in the further electrokinetic experiments compared with the other activation systems. Correspondingly, the leaching concentrations of Zn, Pb, Cu and Cd in the samples were reduced by 85.92%, 98.22%, 88.53% and 98.34%, respectively. The contaminants were continuously extracted from the solid grains of the fly ashes by the protonic attack and bubble implosion. The obtained risk-assessment-code values indicated the adoption of AUS-EKR system reduced the environmental toxicity for the fly ashes to the maximum extent |
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| Beschreibung: | Date Completed 13.08.2018 Date Revised 02.12.2018 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1879-2456 |
| DOI: | 10.1016/j.wasman.2018.01.029 |