Importance of PCDD/F molecules’ polarizability and steric hindrance on their adsorption onto zeolites in a standard EN1948-1 sampling device for incinerator emission monitoring

• Published in: Chemosphere (Oxford) Vol. 259; p. 127457
• Main Authors: Schäf, Oliver, Tortet, Laurence, Simon-Masseron, Angélique, Patarin, Joël, Defour, Stephanie, Blanc, Rosine, Coste, Christophe, Zerega, Yves
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2020; Elsevier
• Subjects: Analytical chemistry; Chemical Sciences; Emission monitoring; PCDD/F; POP; Selective adsorbent; Waste incinerator; Zeolite; POP; PCDD/F; Selective adsorbent; Zeolite; Emission monitoring; Waste incinerator
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2020.127457

Currently, polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) monitoring at stationary sources uses short- and long-term sampling methods compliant with EN1948 standard. The XAD-2 resin is exposed to gas stream for 3–4 weeks (long term), and subsequently analysed in an accredited laboratory for 2 weeks. With the aim of developing an on-line mass spectrometer device using adsorption onto a set of different zeolites as specific adsorbents prior to mass analysis, the paper proposes to firstly test zeolites within the methods compliant with EN1948 standard. In addition to the non-specific external surface adsorption, zeolites possess micropores for adsorbing molecules specifically. Zeolites allowing selective adsorption of only tetra- and penta-chlorinated toxic congeners (TeCDD/F, PeCDD/F) were exposed to the gas flow of a household waste incinerator. As the extraction method of EN 1948 standard does not allow us to discern the two types of adsorption, the adsorbents have been tested at a sampling point located before the last filter. With high congener concentrations, it is expected that the dynamic adsorption properties of the zeolites can be deduced from the breakthrough of some congeners. The electronic interactions between zeolite surface area and PCDD/F involve the polarizability of the molecules. Thanks to the congener breakthrough comparing two zeolite structure types, it has been deduced that toxic TeCDD/F and PeCDD/F were adsorbed in the micropores of FAU-NaX zeolite due to steric compatibility of these congeners. Moreover, the partition of congeners between the condensate and gas phase was elucidated by considering the polarizability of PCDD/F molecules. [Display omitted] •Zeolites are non-conventional adsorbent for PCDD/F adsorption.•Zeolites are exposed to incinerator gas flux.•PCDD/F polarizability governs congener partition between condensates and gas phase.•Electronic interactions between FAU-NaX and PCDD/F involve molecule polarizability.•TeCDD/F and PeCDD/F congeners are adsorbed in FAU-NaX micropores.