The influence of electrodialytic remediation on dioxin (PCDD/PCDF) levels in fly ash and air pollution control residues

• Published in: Chemosphere
• Main Authors: Dias-Ferreira, Celia, Kirkelund, Gunvor M., Jensen, Pernille E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: PERGAMON-ELSEVIER SCIENCE LTD 2016
• Subjects: SOLID-WASTE INCINERATORS; HEAVY-METALS; CHINA; MANAGEMENT; PLANT; Greenland
• Online Access: http://hdl.handle.net/10773/19364; https://doi.org/10.1016/j.chemosphere.2016.01.061

Fly ash and Air Pollution Control (APC) residues collected from three municipal solid waste incinerators in Denmark and Greenland were treated by electrodialytic remediation at pilot scale for 8-10 h. This work presents for the first time the effect of electrodialytic treatment on polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF), and how these levels impact on the valorization options for fly ash and APC residue. PCDD/PCDF levels in the original residues ranged between 4.85 and 197 ng g(-1), being higher for the electrostatic precipitator fly ash. The toxic equivalent (TEQ) varied ten fold, ranging 0.18-2.0 ng g(-1) I-TEQ with penta and hexa-homologs being most significant for toxicity. After the electrodialytic treatment PCDD/PCDF levels increased in the residues (between 1.4 and 2.0 times). This does not mean PCDD/PCDF were synthesized, but else that soluble materials dissolve, leaving behind the non-water soluble compounds, such as PCDD/PCDF. According to the Basel Convention, PCDD/PCDF levels in these materials is low (<15 mu g WHO-TEQ kg(-1)) and the fly ash and APC residue could eventually be valorized, for instance as construction material, provided end-of-waste criteria are set and that a risk assessment of individual options is carried out, including the end-of-life stage when the materials become waste again. (C) 2016 Elsevier Ltd. All rights reserved.