Acrylic acid copolymers as adsorbent materials for the removal of anti-inflammatory pharmaceuticals from synthetic biomedical wastewaters

Abstract In this experimental study, the use of acrylic acid, and 1-vinylimidazole as monomers for the synthesis of one polymer (PVI) and one copolymer (PVI-co-PAA) was examined using trimethylolpropane trimethacrylate as the cross-linking agent. The synthesized polymeric materials were characterized using Fourier transform infrared spectroscopy (FTIR), BET analysis, Thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) and were evaluated towards their adsorption efficiency for the removal of two non-steroidal anti-inflammatory drugs, ibuprofen (IBU) and diclofenac (DCF), from single-component aqueous solutions. Parameters like pH, contact time, initial concentration of the drug and temperature were examined for their possible effect to the process. Acidic conditions appear to favor the uptake of the studied compounds. Moreover, the adsorption equilibrium data were fitted to Langmuir and Freundlich models calculating the maximum adsorption capacity, while Langmuir model exhibited a better fit indicating monolayer coverage of the pharmaceuticals onto the surface of synthesized derivatives. Furthermore, increase of temperature from 25 to 65 ℃ caused an enhancement of the adsorption ability, for both polymeric materials. while thermodynamic analysis revealed the spontaneous and endothermic nature of the process.