Department for Sustainability, ENEA-Italian National Agency for the New Technologies, Energy and Sustainable Economic Development-Casaccia Research Centre, Via Anguillarese 301, I 00123, Rome, Italy.
Department of Electrıcal Electronıc and Computer Engıneerıng, University of Catania, Viale Andrea Doria 6, I 95125, Catania, Italy.
Environ Sci Pollut Res Int. 2018 Dec;25(34):33992-34004. doi: 10.1007/s11356-018-3193-6. Epub 2018 Oct 2.
This paper investigates dynamic variation in the morphologic distribution of dense non-aqueous phase liquids (DNAPLs), which take into account the coupled mass transfer. Experiments were carried out in a 2D tank representing a reconstructed aquifer model. DNAPL dissolution rates were investigated over a wide range of DNAPL saturations, several source configurations, and different hydraulic conditions. Morphometric indexes are presented that take into consideration further factors affecting the dissolution process. Local information regarding transport parameters related to the characteristics of the medium was obtained through a neural network and an optimization algorithm applied to experimental tracer tests. The history of DNAPL source architecture, in terms of saturation, indentation grade, and orientation, was determined by image analysis. Dissolved concentrations were registered and mass transfer rate coefficients were obtained for a wide range of source-zone configurations. A statistical analysis was performed to develop a constitutive equation that is descriptive of the mass transfer rate as a function of source-zone metric characteristics. A new empirical dissolution model using the proposed morphometric parameters is presented and compared with other models. The mass transfer correlation reported incorporates morphometric parameters and considers the complex and variable architecture of non-miscible contaminants. The proposed correlation can be used for an initial assessment of non-aqueous phase liquid (NAPL) dissolution rates over a wide range of saturation (residual and non-residual) conditions and different aqueous phase velocities within the NAPL source zone.
本文研究了考虑耦合传质作用的稠密非水相液体（DNAPL）形态分布的动态变化。实验在一个代表重建含水层模型的二维水箱中进行。在广泛的 DNAPL 饱和度、几种源配置和不同水力条件下，研究了 DNAPL 的溶解速率。提出了形态计量指标，考虑了影响溶解过程的其他因素。通过神经网络和优化算法应用于实验示踪试验，获得了与介质特性有关的传输参数的局部信息。通过图像分析确定了 DNAPL 源结构的历史，包括饱和度、凹陷等级和方向。记录了溶解浓度，并获得了广泛的源区配置的传质速率系数。进行了统计分析，以建立一个描述传质速率作为源区度量特征函数的本构方程。提出并比较了一种使用所提出的形态计量参数的新经验溶解模型。报告的传质相关性包含形态计量参数，并考虑了不可混溶污染物的复杂和可变结构。所提出的相关性可用于在广泛的饱和度（残余和非残余）条件和非水相液体源区内不同的水相速度下，对非水相液体（NAPL）溶解速率进行初步评估。
