Ibuprofen is one of the most widely used pharmaceuticals, and due to its inefficient removal by conventional wastewater treatment, it can be found in natural surface waters at high concentrations. Recently, we demonstrated that the TpBD-(CF3)2 covalent organic framework (COF) can adsorb ibuprofen from ultrapure water with high efficiency. Here, we investigate the performance of the COF for the extraction of ibuprofen from natural water samples from a lake, river, and estuary. In general, the complexity of the natural water matrix induced a reduction in the adsorption efficiency of ibuprofen as compared to ultrapure water. The best performance, with over 70% adsorption efficiency, was found in lake water, the sample which featured the lowest pH. According to the theoretical calculations, ibuprofen more favorably interacts with the COF pores in the protonated form, which could partially account for the enhanced adsorption efficiency found in lake water. In addition, we explored the effect of the presence of competing pharmaceuticals, namely, acetaminophen and phenobarbital, on the ibuprofen adsorption as binary mixtures. Acetaminophen and phenobarbital were adsorbed by TpBD-(CF3)2 with low efficiency and their presence led to an increase in ibuprofen adsorption in the binary mixtures. Overall, this study demonstrates that TpBD-(CF3)2 is an efficient adsorbent for the extraction of ibuprofen from natural waters as well.

Centre for Scientific and Technical Research on Arid Regions Omar El Bernaoui CRSTRA University Campus Med Kheider BP 1682 R P Biskra 07000 Algeria

Faculty of Mathematics and Physics Charles University Ke Karlovu 3 121 16 Prague Czech Republic

International Iberian Nanotechnology Laboratory Avenida Mestre José Veiga 4715 330 Braga Portugal

National Polytechnic School Environmental Engineering Department Laboratory of Sciences and Environmental Techniques 10 Avenue Hacen Badi BP182 El Harrach Algiers 16200 Algeria

Organic Chemistry Natural Products and Food Stuffs Research Unit Department of Chemistry University of Aveiro Campus Universitário de Santiago 3810 193 Aveiro Portugal