Efficient removal of Ag+ and Cu2+ using imine-modified/mesoporous silica-coated magnetic nanoparticles

The present work focuses on the synthesis and application of imine-modified silica-coated magnetic (IM-SCM) nanoparticles. The X-ray diffraction (XRD) tests indicated the presence of highly crystalline cubic spinel magnetite both before and after coating with the silica. The FTIR spectra also proved the successful surface coating and imine-modification of the Fe3O4 nanoparticles. Further investigations were performed to examine the capability of the modified IM-SCM nanoparticles for simultaneous removal of Ag+ and Cu2+ from the water samples. Atomic absorption spectrometry was used for ion determination. The best operating conditions for removing the target ions were a pH=5-9 and a stirring time=30 min. Only 20 mL of 3M nitric acid was used for stripping the ions using the IM-SCM nanoparticles. The resulting data were found to fit well with the Langmuir model, and the maximum capacity of the adsorbent was determined to be 270.3 (± 1.4) mg and 256.4 (± 0.9) mg of Ag+ and Cu2+ /g of IM-SCM, respectively. The adsorbent was successfully used for simultaneously removing the target ions from the wastewater samples.