Matching periodate peak absorbance by far UVC at 222 nm promotes the degradation of micropollutants and energy efficiency.

Periodate (PI)-based advanced oxidation processes have gained increasing interest. This study for the first time elevates the light-activation capacity of PI by using far UVC at 222 nm (UV ₂₂₂ /PI) without extra chemical inputs. The effectiveness and the underlying mechanisms of UV ₂₂₂ /PI for the remediation of micropollutants were studied by selecting atenolol (ATL) as a representative. PI possessed a high molar absorption coefficient of 9480-6120 M ^-1 cm ^-1 at 222 nm in the pH range of 5.0-9.0, and it was rapidly decomposed by UV ₂₂₂ with first-order rate constants of 0.0055 to 0.002 s ^-1 . ATL and the six other organic compounds were effectively degraded by the UV ₂₂₂ /PI process under different conditions with the fluence-based rate constants generally two to hundred times higher than by UVA photolysis. Hydroxyl radical and ozone were confirmed as the major contributors to ATL degradation, while direct photolysis also played a role at higher pH or lower PI dosages. Degradation pathways of ATL were proposed including hydroxylation, demethylation, and oxidation. The high energy efficiency of the UV ₂₂₂ /PI process was also confirmed. This study provides a cost-effective and convenient approach to enhance PI light-response activity for the treatment of micropollutants.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier B.V. All rights reserved.)