Expeditious removal of PCDD/Fs from industrial waste incinerator fly ash using electrogenerated homogeneous Ag(II) ions

• PCDD/Fs removal is more important due to toxic to human and environment.
• Electro-generation of Ag(II) is more favored at low temperature (20 °C).
• Solution 1,2,3,4-TCDD removed 99.75% in 10 s using free electro-generated Ag(II) ions.
• Fly ash contains PCDD/Fs removed 89% in 10 s using electro-generated Ag(II) ions.

This paper summarizes the removal of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in fly ash obtained from industrial waste incinerators using electrochemically-generated homogeneous Ag(II) ion as a mediator. The initial Ag(II) generation experiment showed higher oxidation efficiency (0.018 M out of the 0.025 M) of Ag(II) at a lower temperature (20 °C), which decreases with increasing temperature. Then, the reaction between electrogenerated Ag(II) ion and dioxins was operated at 20 °C using a batch reactor for further analysis. First, an experiment examining the removal of a commercial pure 2,3,7,8-TCDD congener solution with a feed concentration of 2.4 ng/L in a batch reactor for a 10 s using electrogenerated Ag(II) revealed 99.75% removal with a resulting concentration of 1.48 pg/L according to high-resolution gas chromatograph/high-resolution mass spectrometry (HRGC/HRMS) analysis (calculated using the UN-EPA method of 1613b). Similar experimental conditions for the removal of fly ash from incinerators with a feed concentration of 58 pg-TEQ/g resulted in 6.68 pg-TEQ/g, which is an approximately 89% removal efficiency for 10 s reaction duration. The developed method is quite promising for the very short time (10 s, first time), removal of dioxins in fly ash from an industrial incinerator.

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