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BACKGROUND Low‐cost biosorbent (derived from peanut shells) with abundant oxygen‐containing functional groups can effectively adsorb the naproxen drug in solution. This study aimed to explore the main interactions responsible for adsorbing naproxen and develop several conventional methods for identifying primary adsorption mechanism. Some important operation parameters strongly effecting the adsorption process and mechanism were investigated and discussed. RESULTS: A fast adsorption equilibrium can be reached at approximately 120 min. The Langmuir maximum adsorption capacity of biosorbent towards naproxen (Qomax; mg g−1) was 55.1 mg g−1. The study of adsorption thermodynamics indicated that the adsorption process was spontaneous (∆G° ≈ −21 kJ mol−1) and exothermic (∆H° = −14.9 kJ mol−1), and van der Waals force played an important role in the adsorption mechanism. Another important contribution of n–π interaction between the carbonyl groups on the biosorbent's surface and the aromatic rings in naproxen molecules was confirmed by Fourier‐transform infrared spectroscopy and a traditional method. Such n–π interaction cannot be well performed when carbonyl groups were oxidized into carboxylic groups under H2O2 treatment. Peanut shells exhibited an excellent adsorption capacity to various pollutants such as lead (Qomax = 167 mg g−1), cadmium (103 mg g−1), cobalt (88.8 mg g−1), diclofenac (56.1 mg g−1), and bisphenol A (24.5 mg g−1). CONCLUSIONS: Simple methods were developed to identify the important role of van der Waals force and n–π interaction in the adsorption process of naproxen. Such methods might be applied to identify the similar adsorption mechanisms of other aromatic adsorbates onto other materials with similar properties. Peanut shells can serve as a promising biosorbent for eliminating naproxen and other pollutants from water environment. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

In this study, new luminescent coordination polymers containing cadmium ions, 1,10-phenanthroline and benzene-1,3,5-tricarboxylic acid ligands were synthesised under hydrothermal conditions. The structure of the synthesised Cd(II) CPs was investigated by X-ray diffraction, scanning electron microscope, matrix-assisted laser desorption ionisation mass spectrometry, elemental analysis, thermogravimetric analysis and Fourier transform infrared spectroscopy. In addition, the adsorption and sensing applications of Cd(II) CPs were investigated. The removal of diclofenac, an organic micropollutant, from aqueous systems was investigated for the adsorption application of Cd(II) CPs. The adsorption isotherms fitted the Langmuir model better than the Freundlich model. Adsorption equilibrium was reached after 240 min at pH 6.5 and 298 K, resulting in a maximum adsorption capacity of 1822 mg/g. In the other analytical application of Cd(II) CPs, the detection of Cu2+ and Ni2+ cations in aqueous medium was investigated based on their fluorescence properties. According to the results Cd(II) CPs have better sensitivity and selectivity. The fluorescence intensity of Cd(II) CPs decreased linearly due to the quenching mechanism. The K SV values were calculated to be 1.82 × 108 M−1 for Cu2+ and 8.2 × 108 M−1 for Ni2+. The limits of detection Cu2+ and Ni2+ cations for Cd(II) CPs were calculated to be 2.78 × 10−8 and 6.15 × 10−9 M, respectively. The detection of Cu2+ and Ni2+ ions was performed with a fast response, a wide linear range and a very low detection limit and could be used on real water samples without any matrix interference. [Display omitted] • Cd(II) CPs were hydrothermally synthesized with a mixed ligand. • Cd(II) CPs have used removal of diclofenac and detection of Cu2+ and Ni2+. [ABSTRACT FROM AUTHOR]