Synthesis and characterisation of modified magnetite super paramagnetic nano composite for removal of toxic metals from ground water

In this study a novel type of EDTA-Surface functionalized Si-coated magnetite nano particles were synthesized. Being hexadentate ligand EDTA (ethylene-di-ammine tetra acetic acid) has a higher rate of chelation or complication with toxic metals thus enhancing the removal efficiency of nanosorbents. Magnetite nanoparticles (Fe₃O₄) were synthesized by a simple chemical co-precipitation route and silica-coating on its surface was done by hydrolysis of tetraethoxy silane (TEOS). EDTA was functionalised on the surface of Si-coated magnetite nanoparticles in acidic medium (PH=4–4.6) through a complex reaction mechanism. The resultant nanosorbents were well dispersed in water. Their surface morphology was studied by SEM which also showed nanoparticles had the mean diameter 12-13nm. XRD result showed the prominent peak of Fe₃O₄ at 2Θ=35° and its cubic spinel structure.

FT-IR spectra revealed that fictionalization of ethylene-diammine tetra acetic acid on the surface of Si-coated Fe₃o₄ was successfully done as characteristics peak-of –COOH was depicted clearly. The chemical composition were determined by EDX and the relative ratio of O, Fe, Si and C elements clearly indicated the successful preparation of surface functionalized magnetite nano particles. Their magnetic property was determined by VSM and result showed that the nano particles were super paramagnetic and inert silica coating and fictionalization did not reduce the magnetic property markedly. Finally it was tested with.1M standard CuSO₄ solution for the adsorption of copper and found that only.11 gram nonabsorbent was able to adsorb copper up to 66% from the solution in less than 15 minutes. Result was obtained by optimizing PH-(6) and at room temperature.