Synthesis and characterization of absorbents based on 1-hydroxypropyl, 3-methylimidazole derivatives and sulphonated poly (ether ether ketone)

Adsorption is a preferred decontamination process for the treatment of industrial effluents, and various materials have been developed for this purpose. In the present work, esters based on sulfonated poly(ether ketone)/ionic liquids were prepared and their structures were evaluated by Fourier transform Infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopies. Batch adsorption experiments were carried out on a mixed solution comprising Pb²⁺, Cu²⁺, Cd²⁺ and Zn²⁺ ions with concentration ranging from 4 to 10 μg L^-1. The adsorption affinity of the esters expressed as the equilibrium metal ions uptake capacity, q_e (mg g^-1) was in the order: Pb²⁺ (6.2), Cd²⁺ (5.1), Cu²⁺ (2.8) and Zn²⁺ (0.8). It was interesting to observe the low values of qe of all adsorbents for Zn²⁺, which is advantageous in the treatments of wastewater as Zn²⁺ present in high concentration and could reduce the ion exchange capacity of the adsorbent largely toward other metal ions pollutant. Esterification with ionic liquids open the opportunity to upcycle polymer wastes that can be sulfonated, such as polystyrene, PEEK and its cross-linked form.