Degradation, boosted with Fe ²⁺ ions, of ethylene glycol in oxygen-saturated aqueous solutions using the H ₂ O ₂ /UV-C oxidation system: a kinetic study

Ethylene glycol (EG) is commonly found as the main organic contaminant in airport runoff water during the cold season due to its use in the composition of de-icing fluids. Despite relatively low acute and chronic toxicity, EG may lead to a rapid growth of undesirable microbial biofilms in water bodies, thus reducing the concentration of dissolved oxygen and suppressing biodiversity. EG degradation using hydrogen peroxide activated with UV‑C light (H2O2/UV‑C) is a promising method of solving this problem because H2O2 serves as a cheap and green oxidant and provides complete EG mineralization in aqueous solutions. This paper describes the results of the in-depth study on the effect of adding Fe2+ ions and saturating the reaction solution with oxygen on EG degradation in the H2O2/UV system, showing the synergistic effect of both these factors on boosting the rate of EG removal and the depth of its mineralization. Comprehensive analysis of EG degradation and individual oxidation of key EG intermediates using TOC and HPLC methods revealed the roles of Fe2+ ions and dissolved oxygen in the synergistic effect and allowed us to clarify the main pathways of EG degradation in this system.