Department of Chemistry, Faculty of Chemistry, "Alexandru Ioan Cuza" University of Iasi, 11 Carol I, 700506Iasi, Romania.
Integrated Centre of Environmental Science Studies in the North Eastern Region (CERNESIM), "Alexandru Ioan Cuza" University of Iasi, 11 Carol I, 700506Iasi, Romania.
Environ Sci Technol. 2022 Nov 15;56(22):15650-15660. doi: 10.1021/acs.est.2c04867. Epub 2022 Oct 14.
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 NO 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 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.
水体与大气之间的分配是一个重要的过程，影响着半挥发性污染物的归宿和传输。在这项工作中，采用了一种将实验数据和模型相结合的简单方法，研究了半挥发性污染物在两相体系（地表水+大气）中的降解情况。4-异丁基苯乙酮（IBAP）被选为模型污染物；IBAP 是一种非甾体抗炎药布洛芬的有毒转化产物。研究表明，IBAP 的大气行为主要受与 OH 自由基反应的控制，而由 NO 引发或直接光解的降解则可以忽略不计。本研究强调了 IBAP 与 OH 的气相反应比从水相系统中可能的蒸发动力学更快。因此，可能很难检测到气相中的 IBAP。然而，在一个深层且富含有机碳的水体中，多达 60%的 IBAP 可能会通过蒸发和随后与气相 OH 的反应而被消除。本研究表明，对于像 IBAP 这样最初存在于与大气接触的天然水体中的半挥发性有机化合物的气相化学，在某些环境条件下可能具有非常重要的意义。
