Fe3O4@SiO2@THPP (MSTHPP) nanocomposite was prepared as an adsorbent for the removal of lead ions. The structural characteristics of this nanocomposite were determined using Fourier transform-infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy, x-ray diffraction, vibrating sample magnetometry (VSM), and N2 adsorption-desorption analyses. SEM images showed that the magnetic nanoparticles have uniform morphologies with a mean size of 20 nm. The magnetic properties of the synthesized nanocomposite were measured on a VSM with maximum saturation magnetization values of 40 emug1 and 10 emug1 for Fe3O4@SiO2 and MSTHPP nanocomposites, respectively. MSTHPP has been efficiently used to remove lead ions from aqueous solutions. After the lead sorption process, the nanocomposite was magnetically separated from the mixture and showed good reusability. The effects of pH, contact time, adsorbent dosage and initial concentration of lead in the removal of lead were investigated. Optimization of the parameters was performed by using Taguchi design method to obtain the maximum removal efficiency. The optimized condition can be achieved when pH, contact time, adsorbent dosage and initial concentration of lead are 5.3 min, 30 min, 50 mg, 20 ppm, respectively. The M, MS, and MSTHPP lead removal efficiency was found to be 18%, 25%, and 97%, respectively.
