Molecular insights on the adsorption of some pharmaceutical residues from wastewater on kaolinite surfaces

Non-negligible concentrations of chemicals products are often contained in worldwide wastewaters. Although they can be eco-toxic, generally poorly removed water treatment plants. Their accumulation the environment has become a crucial problem since present serious risk to flora and fauna. An important fraction these molecules pharmaceuticals, including ibuprofen, paracetamol, aspirin, diclofenac –anti-inflammatory drugs, carbamazepine, diazepam – anti epileptic medications. adsorption onto clay minerals particularly on kaolinite offers an efficient cheap perspective for wastewaters depollution. In this work, we investigated mechanisms eventual competition by means density functional theory calculations. We show that compounds adsorb more favorably than (0 0 1) basal aluminol-terminated surface mainly through hydrogen, ?, London interactions. The most strongly adsorbed molecule is with energy ?159.4 kJ.mol?1, while less diazepam, ?96.8 kJ.mol?1. This latter only dispersion Also, presents no generating toxic by-products that, heating 360 K, all desorbed, which demonstrates regenerability material. Hence, interesting candidate pharmaceutical removal from addition, unravel molecules, offering better understanding common mineral.