| 摘要: | 摘要： •Shows the effects of temperature, time and addition of lime.•Temperature is important, but time is surprisingly little.•Dechlorination makes lower TEQ removal compared with mass removal.•Unexpectedly, addition of lime results in lower PCDD/F removal efficiency. Removal and destruction of dioxin-like congeners, including polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs), from fly ash were investigated at varying pyrolysis temperatures and reaction times and using calcium-based additives. Destruction efficiencies based on TEQ and mass both increase with rising treatment temperature. However, additional low chlorinated PCDD/Fs were formed significantly by dechlorination of high chlorinated PCDD/Fs, at pyrolysis temperatures of 250 and 300°C. Surprisingly, lower destruction efficiencies were realized in the presence of Ca-based additive, compared with those without additive, and TEQ values of fly ash into which CaO was introduced increased, compared with the raw ash, due to significant formation of low chlorinated PCDD/Fs (4–5 Cl). However, complex interactions among unburned carbon, sulfur and metals in the fly ash collected in this study make it difficult to pinpoint the exact causes. The results obtained in this study indicate that degradation and formation of dioxin-like congeners take place simultaneously in pyrolysis process, such as formation of low chlorinated PCDD/Fs via dechlorination of highly chlorinated PCDD/Fs.
其他題名： Chemosphere
出版者： Kidlington: Elsevier Ltd
出版日期： 2013-08-01
出處： Chemosphere (Oxford), 2013-08, Vol.92 (7), p.857-863
版權： 2013 Elsevier Ltd
版權： 2014 INIST-CNRS
版權： Copyright © 2013 Elsevier Ltd. All rights reserved.
識別號： ISSN: 0045-6535
識別號： ISSN: 1879-1298
識別號： EISSN: 1879-1298
識別號： DOI: 10.1016/j.chemosphere.2013.04.042
識別號： PMID: 23714152
識別號： CODEN: CMSHAF |
