Removal of heavy metals by using magnetically reusable Fe3O4@ZnO nanocomposites from Andrographis paniculata leaf extract: a greener way to remove industrial effluents

The ability to repurpose adsorbent was critical for making the sewage treatment system both premium and environmentally beneficial. Toxic metals ions [Pb(II), Cr(II), and Cd(II)] were removed from effluent discharge using Fe3O4/ZnO nanoparticles as sorbent materials. Chemical affinity, zero potentials, XRD, FTIR, and TEM were used to explore the structural and interfaces adsorption process of Fe3O4/ZnO composite in this study. Experiments on absorption, desorption, and recycling were performed. The findings demonstrate that perhaps the toxic metals substituted for H in the Fe–O–H structure and formed the Zn–O–Me structure, implying that metal elimination was accomplished through ion exchange. Cd(II), Pb(II), and Cr(IV) had 99.81%, 99.76%, 98.1%, respectively,adsorptive degradation efficiency. The Langmuir model was shown to be the best fit for describing the absorption on the surface of Fe3O4/ZnO nanoparticles based on the stability data processing. The kinetic parameters of toxic metal ions on the surface of Fe3O4/ZnO composites were relatively similar to the pseudo-second-order concept, according to the kinetics investigations. The trials proved that reprocessing the Fe3O4/ZnO sorbent extracted from water by a magnetic material was a viable option for removing pollutants in an environmentally acceptable and effective manner.