Removal of Cu (II) and Pb (II) from aqueous solution using engineered iron oxide nanoparticles

Nano-sized Fe3O4 and Fe2O3 were synthesized using a precipitation method. The nanomaterials were tested as adsorbents for the removal of both Cu2 + and Pb2 + ions. The nanomaterials were characterized using X-ray powder diffraction to determine both the phase and the average grain size of the synthesized nanomaterials. Batch pH studies were performed to determine the optimum binding pH for both the Cu2 + and Pb2 + to the synthesized nanomaterials. The optimum binding was observed to occur at pH 4 and above. Time dependency studies for Cu2 + and Pb2 + showed the binding occurred within the first 5 min of contact and remained constant up to 2 h of contact. Isotherm studies were utilized to determine the binding capacity of each of the nanomaterials for Cu2 + and Pb2 +. The binding capacity of Fe3O4 with Cu2 + and Pb2 + was 37.04 mg/g and 166.67 mg/g, respectively. The binding capacities of the Fe2O3 nanomaterials with Cu2 + and Pb2 + were determined to be 19.61 mg/g and 47.62 mg/g, respectively. In addition, interference studies showed no significant reduction in the binding of either Cu2 + or Pb2 + to the Fe3O4 or Fe2O3 nanomaterials in the presence of solutions containing the individual ions Na+, K+, Mg2 + and Ca2 + or a solution consisting of a combination of all the aforementioned cations in one solution.