Contaminant transport in soil: A comparison of the Theory of Porous Media approach with the microfluidic visualisation

S M Seyedpour; M Janmaleki; C Henning; A Sanati-Nezhad; T Ricken

doi:10.1016/j.scitotenv.2019.05.095

Contaminant transport in soil: A comparison of the Theory of Porous Media approach with the microfluidic visualisation

Sci Total Environ. 2019 Oct 10:686:1272-1281. doi: 10.1016/j.scitotenv.2019.05.095. Epub 2019 May 16.

Authors

S M Seyedpour¹, M Janmaleki², C Henning³, A Sanati-Nezhad⁴, T Ricken⁵

Affiliations

¹ Institute of Mechanics, Structural Analysis and Dynamics, Faculty of Aerospace Engineering and Geodesy, University of Stuttgart, 70569 Stuttgart, Germany; Institute of Mechanics, Structural Analysis, and Dynamics, TU Dortmund University, 44227 Dortmund, Germany. Electronic address: seyedmorteza.seyedpour@tu-dortmund.de.
² BioMEMS and Bioinspired Microfluidic Laboratory, Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Canada; Center for BioEngineering Research and Education, University of Calgary, Calgary, Canada. Electronic address: mohsen.janmaleki@ucalgary.ca.
³ Institute of Mechanics, Structural Analysis and Dynamics, Faculty of Aerospace Engineering and Geodesy, University of Stuttgart, 70569 Stuttgart, Germany. Electronic address: carla.henning@isd.uni-stuttgart.de.
⁴ BioMEMS and Bioinspired Microfluidic Laboratory, Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Canada; Center for BioEngineering Research and Education, University of Calgary, Calgary, Canada. Electronic address: amir.sanatinezhad@ucalgary.ca.
⁵ Institute of Mechanics, Structural Analysis and Dynamics, Faculty of Aerospace Engineering and Geodesy, University of Stuttgart, 70569 Stuttgart, Germany. Electronic address: tim.ricken@isd.uni-stuttgart.de.

PMID: 31412523
DOI: 10.1016/j.scitotenv.2019.05.095

Abstract

Visualisation of the groundwater flow and contaminant transport can play a significant role for a better understanding of contaminant fate, which helps decision-makers and contaminated site planners to choose and implement the best remediation strategies. In this paper, a microfluidic chip coated with nanoclay was developed to mimic soil behaviour. Scanning electron microscopy (SEM) images and Fourier-transform infrared spectroscopy (FTIR) analysis confirmed that all the features and surfaces are coated with nanoclay. The change of contact angle for the native polydimethylsiloxane (PDMS) from 151^° ± 4^° to 73^° ± 6^° for modified ones is indicative of a considerable shift to hydrophilic behaviour. Moreover, the transport process in the developed chip was simulated utilising the Theory of Porous Media (TPM) and computational fluid dynamic (CFD) approaches. Although the results of both numerical approaches are in good agreement with experiments, the Root Mean Square Error (RMSE) of the predicted contaminant concentration by TPM at two observation points is less than that of CFD.

Keywords: Computational fluid dynamic (CFD); Contaminant transport; Microfluidics; Nanoclay; Polydimethylsiloxan (PDMS); Theory of Porous Media (TPM).