Evaluation of the Environmental Fate of a Semivolatile Transformation Product of Ibuprofen Based on a Simple Two-Media Fate Model

Abstract

Partitioning between surface waters and the atmosphere is an important process, influencing the fate and transport of semi-volatile contaminants. In this work, a simple methodology that combines experimental data and modeling was used to investigate the degradation of a semi-volatile pollutant in a two-phase system (surface water + atmosphere). 4-Isobutylacetophenone (IBAP) was chosen as a model contaminant; IBAP is a toxic transformation product of the non-steroidal, anti-inflammatory drug ibuprofen. Here, we show that the atmospheric behavior of IBAP would mainly be characterized by reaction with •OH radicals, while degradation initiated by •NO3 or direct photolysis would be negligible. The present study underlines that the gas-phase reactivity of IBAP with •OH is faster, compared to the likely kinetics of volatilization from aqueous systems. Therefore, it might prove very difficult to detect gas-phase IBAP. Nevertheless, up to 60% of IBAP occurring in a deep and dissolved organic carbon-rich water body might be eliminated via volatilization and subsequent reaction with gas-phase •OH. The present study suggests that the gas-phase chemistry of semi-volatile organic compounds which, like IBAP, initially occur in natural water bodies in contact with the atmosphere is potentially very important in some environmental conditions.

Assessing the Photodegradation Potential of Compounds Derived from the Photoinduced Weathering of Polystyrene in Water

“…•-, or volatilise to the gas phase where it would react with • OH (g) , similarly to other semivolatile compounds (Arsene et al, 2022). The overall scenario is depicted in Scheme 1a, and two specific scenarios are illustrated in Scheme 1b.…”

“…Starting from AcPh in water (AcPh w ) at initial concentration C o , the kinetic system depicted in Scheme 1 gives the time trends for [AcPh w ] and [AcPh g ] (w = water phase, g = gas phase) described by Eqs. ( 2), (3), which are solutions of differential equations and were derived in similar way as Arsene et al (2022) (see Scheme 1 for the meaning of the different parameters):…”

Possible Effects of Changes in Carbonate Concentration and River Flow Rate on Photochemical Reactions in Temperate Aquatic Environments

“…The biological elimination of biorecalcitrant CECs from surface-water environments is usually as problematic as it is in WWTPs, thus abiotic processes play an important role in the attenuation of these compounds. Abiotic processes include hydrolysis, partitioning to other phases (e.g., sediments or the gas phase) that are possibly followed by transformation [6], and aqueous-phase photodegradation [7].…”