Volatilization of hazardous hydrophobic organic compounds is often observed in many water, wastewater and soil treatment (bio)processes. Several models have been developed to quantify and predict gas-liquid pollutant transfer, being the proportionality coefficient model (PCM) one of the most commonly used, particularly in wastewater treatment. The PCM is based on the use of oxygen as a reference compound, which has a low resistance to the transfer in the gas phase. However, this resistance might be important for (semi-)volatile organic compounds – or (semi-)VOCs, which may render the use of the PCM model inaccurate. This study proposes an experimental methodology and a modeling approach for the use of the two-reference compound model (2RCM) that considers both the liquid-side and the gas-side resistances, by using water and oxygen as references. Results showed that the 2RCM predicts more accurately the overall mass transfer coefficients than the PCM for a VOC and two semi-VOCs tested in this study. In addition, the 2RCM was found to be a more robust method to estimate mass transfer coefficient of any compound and its use can be extrapolated to all substances. Finally, the relevance and limitations of both models was established.

在许多水、废水和土壤处理（生物）过程中经常观察到有害疏水性有机化合物的挥发。已经开发了几种模型来量化和预测气液污染物转移，其中比例系数模型 (PCM) 是最常用的模型之一，特别是在废水处理中。PCM 是基于使用氧气作为参考化合物，它对气相中的转移具有低阻力。然而，这种阻力对于（半）挥发性有机化合物或（半）VOC 可能很重要，这可能会导致 PCM 模型的使用不准确。本研究提出了一种实验方法和建模方法，用于使用水和氧气作为参考，同时考虑液体侧和气体侧阻力的双参考复合模型 (2RCM)。结果表明，对于本研究中测试的一种 VOC 和两种半 VOC，2RCM 比 PCM 更准确地预测了整体传质系数。此外，发现 2RCM 是一种更可靠的方法来估计任何化合物的传质系数，并且它的用途可以外推到所有物质。最后，确定了两种模型的相关性和局限性。