The study was aimed at evaluating the catalytic and photocatalytic properties of lignite fly ash samples, S1 and S2, from the Pilsen Power Station (Teplárna Plzeň) collected using electrostatic precipitators with relatively high contents of Fe2O3 (6.0–7.4%) and TiO2 (4.6–4.8%). Iron oxides are used often as heterogeneous Fenton(-like) reaction catalysts in certain compositions, as they have iron oxides and oxo-hydroxides attached to catalyst supports with developed contact surfaces, such as zeolites [1,2]. TiO2 is the most studied photocatalyst for the photocatalytic oxidation of gaseous volatile organic compounds (VOCs) [3]. Experimental tests investigating the catalytic oxidation of the textile dye Acid Orange 7 in aqueous solutions, using the heterogenous Fenton-like system (H2O2/fly ash) and the photocatalytic oxidation of acetone vapors in the UV-A/fly ash system, were carried out. In water treatment trials, adsorption and Fenton-like experiments were carried out in parallel, under similar treatment conditions. The adsorption of the VOC was characterized by its concentration in the reactor’s effluent growing with the adsorbent saturation with the acetone vapors. Once the studied sample of fly ash had accumulated a certain amount of acetone, the UV-A light was switched on to start the photocatalytic oxidation reaction. The results showed moderate catalytic and negligible photocatalytic properties of S1 and S2 in the studied systems, although they exhibited certain adsorption properties. Surprisingly, S2 showed a noticeably stronger catalytic ability in the Fenton-like system than S1, despite having an almost 2.6 times lower surface area at a similar chemical composition. The fly ashes were also used for zeolite synthesis [4]. They were subsequently tested in ion exchange with respect to ammonium cations and showed abilities close to those of a commercial zeolite specimen.
Author Contributions
Conceptualization, J.B., N.D., and M.K.; methodology, J.B., N.D., and M.K.; formal analysis, J.B., N.D., L.P., and M.K.; investigation, D.N., J.B., N.D., and M.K.; resources, L.P., M.V., and S.P.; writing—original draft preparation, N.D. and M.K.; writing—review and editing, N.D., and S.P.; visualization, J.B., N.D., and M.K.; supervision, N.D. and S.P.; funding acquisition, M.V., and S.P. All authors have read and agreed to the published version of the manuscript.
Funding
This work has received funding from the European Union’s Horizon 2020 Research and Innovation Programme, ERA-NET Confund on Raw Materials (ERA-MIN3) via the project ABtomat (JTC-2021_131).
Data Availability Statement
Data supporting the results presented can be provided upon request to the corresponding author.
Conflicts of Interest
The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.
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