Triclosan removal using high-silica zeolites: A novel insight via statistical physics modelling

This research describes the application of a double molecular stacking model, based on statistical physics theory, to analyze and explain the adsorption mechanism of triclosan on different high-silica zeolites. Modelling results indicated that molecules of this pollutant were adsorbed via different configurations on surfaces of tested zeolites where non-parallel, parallel, and mixed orientations occurred depending on tested systems. The adsorption capacities to remove triclosan from water using high-silica zeolites depended on their composition and textural parameters where the best zeolite showed a high surface area. Calculated adsorption energies ranged from 15 to 26 kJ/mol for all tested systems. This modelling approach indicated that triclosan separation mechanism was controlled by physical interactions where hydrogen bonding and van der Waals forces played a relevant role to remove this pollutant. A thermodynamic analysis of these adsorption systems was also performed. These theoretical results contribute to characterize the adsorption properties and mechanism of high-silica zeolites to remove toxic organic compounds from water.