Synthesis of magnetic CMC bionanocomposite containing a novel biodegradable nanoporous polyamide selectively synthesized in ionic liquid as green media: Investigation on Nd+3, Tb+3, and Dy+3 rare earth elements adsorption

In this research study, the carboxymethyl chitosan/poly(pyrimidine-thiophene-amide)/Ni0.2Zn0.2Fe2.6O4 (CMC/P(PTA)/Ni0.2Zn0.2Fe2.6O4) was prepared as a novel magnetic bionanocomposite adsorbent. FE-SEM, EDX, NMR, XRD, FT-IR, and VSM techniques were applied for the analyses of the products. The adsorption behavior of the prepared bionanocomposite was investigated towards Nd+3, Tb+3, and Dy+3 as adsorbates. The adsorption process was evaluated considering the influence of independent parameters including pH of the solution, contact time, adsorbent dosage, initial metal ions concentration, and ionic strength. The adsorption efficiency values of 98.15, 97.6, and 99.42% were respectively obtained for Nd+3, Tb+3, and Dy+3 at optimum conditions of pH = 5.5, 30 mg/L of the ions, adsorbent dosage of 0.06 g, and contact time of 90 min. The data of the adsorption equilibrium of the ions were fitted well by Freundlich model. Kinetic studies showed that Nd+3, Tb+3, and Dy+3 adsorption followed both pseudo-second-order (PSO) and intra-particle diffusion (IPD) kinetic models. The values of ΔH° indicated that the ions adsorption process onto the bionanocomposite was endothermic, and the ΔG° values revealed that it was spontaneous at higher temperature. The CMC/P(PTA)/Ni0.2Zn0.2Fe2.6O4 could be regenerated by 0.2 M HNO3 and its separation was viable utilizing a magnetic field with the saturation magnetization value of 14.88 emu/g. •The novel biodegradable poly(pyrimidine-thiophene-amide) P(PTA) was synthesized.•NMR analysis confirmed that the P(PTA) was synthesized successfully.•The magnetic carboxymethyl chitosan/P(PTA) was prepared by the gelation method.•The saturation magnetization value of the bionanocomposite was 14.88 emu/g.•Freundlich model fitted the adsorption equilibrium data of Nd+3, Tb+3, and Dy+3.