[PO-D2] Poster Session 2

[P2-29] Aquatic pollutant removal by adsorption in zeolite structures: An experimental and molecular simulation study

^○Mate Erdos¹, Nan Jiang², Sebastian G. J. Heijman², Othonas A. Moultos¹ (1.Process & Energy Department, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Netherlands, 2.Department of Water Management, Faculty of Civil Engineering and Geosciences, Delft University of Technology, Netherlands)

Water contamination with micropollutants poses a serious threat to public health and the ecosystem. Technologies based on adsorption are widely used to remove micropollutants (inorganic and organic) from wastewater. Zeolites show a promising potential as adsorbents in these applications. Zeolites are crystalline, microporous aluminosilicates with well-defined 3-dimensional structure, composed of tetrahedral SiO₄ and AlO₄ clusters connected to each other by shared oxygen atoms. To compensate the charge imbalance caused by the aluminum content of the framework, exchangeable cations (usually alkali and alkaline earth cations) are located in the cavities of the structure. By removing the aluminum content of the framework the hydrophobicity of the zeolite can be increased, providing favorable adsorption characteristic to organic molecules. In this study, the effect of aluminium content of zeolite structures for aquatic pollutant removal are investigated. To that end, molecular simulations using Monte Carlo method are performed. In comparison with experimental methods, these simulation techniques can provide fundamental understanding of the nano scale behavior of the system which is crucial for designing new materials.
In this study, two types of zeolites (FAU, BEA) with different aquatic pollutants (2,4,6-trichlorophenol, triclosan) are investigated experimentally and with simulations. The simulated and experimentally measured results show qualitative agreement. To obtain insights into the adsorption mechanisms, radial distribution functions, and the distribution of adsorbates are calculated for each structure. The preferred adsorption sites and configuration of adsorbates (e.g., pi-pi stacking, H-bonding) are identified for each adsorbates and structures. Based on the simulation and experimental results the relationship of aluminium content and adsorption affinity can be determined and the performance of the different zeolites can be evaluated.