Carbon and hydrogen isotope fractionation of phthalates during photocatalysis reactions in aqueous solution containing Fe(III) complexes or iron minerals

Ning Min; Jun Yao; Hao Li; Junjie Zhu; Steffen Kümmel; Oliver J Lechtenfeld; Thomas Schaefer; Hartmut Herrmann; Hans Hermann Richnow

doi:10.1016/j.watres.2023.120740

Carbon and hydrogen isotope fractionation of phthalates during photocatalysis reactions in aqueous solution containing Fe(III) complexes or iron minerals

Water Res. 2023 Oct 12:247:120740. doi: 10.1016/j.watres.2023.120740. Online ahead of print.

Authors

Ning Min¹, Jun Yao², Hao Li³, Junjie Zhu³, Steffen Kümmel⁴, Oliver J Lechtenfeld⁴, Thomas Schaefer⁵, Hartmut Herrmann⁵, Hans Hermann Richnow⁶

Affiliations

¹ School of Water Resources and Environment and Research Center of Environmental Science and Engineering, Sino-Hungarian Joint Laboratory of Environmental Science and Health, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian District, 100083 Beijing, China; Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany.
² School of Water Resources and Environment and Research Center of Environmental Science and Engineering, Sino-Hungarian Joint Laboratory of Environmental Science and Health, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian District, 100083 Beijing, China. Electronic address: [email protected].
³ School of Water Resources and Environment and Research Center of Environmental Science and Engineering, Sino-Hungarian Joint Laboratory of Environmental Science and Health, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian District, 100083 Beijing, China.
⁴ Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany.
⁵ Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany.
⁶ School of Water Resources and Environment and Research Center of Environmental Science and Engineering, Sino-Hungarian Joint Laboratory of Environmental Science and Health, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian District, 100083 Beijing, China; Helmholtz Centre for Environmental Research - UFZ, Permoserstr. 15, 04318 Leipzig, Germany; Isodetect GmbH, Deutscher Platz 5b, 04103 Leipzig. Germany. Electronic address: [email protected].

PMID: 39492359
DOI: 10.1016/j.watres.2023.120740

Abstract

The hydrogen and carbon isotope fractionation factor (ε²H, ε¹³C) of dimethyl-, diethyl‑ and dibutyl phthalic acid ester during photosensitized degradation by artificial sunlight with Fe(III) ions and iron minerals (hematite, goethite and magnetite) in aqueous solution were examined by compound-specific isotope analysis (CSIA) in order to analyze the degradation mechanism. Hematite does not catalyze photosensitized degradation of phthalates. The correlation of ²H and ¹³C isotope fractionation (Λ = Δδ²H/Δδ¹³C) of phthalates with increasing chain length (dimethyl-; diethyl‑; and dibutyl-) were compared with values of the ∙OH radical model reaction with the aromatic ring as well as acidic and alkaline hydrolysis. The Λ values of die photosensitized reaction of diethyl phthalate with goethite (-5.1 ± 1.8) and magnetite (-18.9 ± 3.9) show a large difference compared to Fe(III) solutions (4.7 ± 0.9 to 4.8 ± 1.0) suggesting specific reaction mechanisms. The fractionation factors determined here have potential to characterize the degradation of phthalates catalyzed by photo-induced reaction of Fe(III), goethite and magnetite in natural system and in remediation approaches.

Keywords: Compound specific isotope analysis; Fe-minerals; Photochemistry; Photosensitized degradation; Phthalates.