Synthesis, characterization, and application of polypyrrole/Fe3O4 nanocomposite for removal of Ni(II) ions from water and wastewaters

The purpose of this research work is to investigate the sorption characteristic of Polypyrrole/Fe3O4 (PPy/Fe3O4) nanocomposite (NC) for the removal of Ni(II) ions from aqueous solutions. The adsorbent was characterized using SEM, FTIR, and XRD. The SEM micrographs show the formation of PPy/Fe3O4 NC within 32-41 nm in size which has been homogeneously dispersed. The sorption of Ni(II) ions by a batch method was carried out and the optimum conditions were investigated. To determine the optimal conditions for adsorption, the effect of important parameters such as pH, contact time, initial concentration of Ni(II), amount of adsorbent, and temperature were investigated. Two models, Lagergren and pseudo-second order have been tested to track the kinetics of the removal process. Adherence of the adsorption process from pseudo-second-order kinetics and chemical adsorption was proved. The Langmuir and Freundlich were employed for the treatment of the equilibrium adsorption data and yielded a good fit with the Freundlich isotherm model. The PPy Fe3O4 NC has considerable Langmuir adsorption capacity to Ni(II) removal 250.0 mg/g. The adsorption process was exothermic with a negative value of Delta H degrees (- 21.9 kJ/mol) and spontaneous in nature (Delta G degrees = - 7.03 kJ/mol). The results have established the good potentiality of the Polypyrrole/Fe3O4 NC to remove Ni(II) from aqueous solutions.