“box behenken design optimization for heavy metal sorption on novel magnetic amino/thiol functionalized nanoparticles'

In this study, a novel amino/thiol functionalized superparamagnetic nanoparticle was synthesized and applied as an effectual nanosorbent to uptake pb2+ and cd2+. to synthesize the amino/thiol magnetic nanoparticles (fe3o4@sio2-n2s), fe3o4@sio2 was functionalized by thio-(3-glycidyloxopropyl)trimethoxysilan (glymo-s) and modified by ring-opening reaction between glymo-s and ethylenediamine. the magnetic nanoparticles (mnps) were characterized by transmission electron microscopy (tem), field emission scanning electron microscopy (fe-sem), x-ray powder diffraction (xrd), thermo gravimetric analysis (tga), vibrating sample magnetometer (vsm) and fourier transform infrared spectroscopy (ft-ir) and confirmed the presence of nitrogen and sulfur containing functional groups on fe3o4@sio2 mnps. to investigate the effective parameters and optimize the removal conditions, the box behnken design (bbd) based on response surface methodology (rsm) was applied. in optimum conditions fe3o4@sio2-n2s adsorbed pb2+ (93.5 mg g-1) and cd2+ (80.64 mg g-1) at ph 7, adsorbent dosage 16 mg and contact time 55 min. the data revealed the heavy metal ions removal followed the pseudo-second-order kinetic model (r2 = 0.98) and langmuir isotherm (r2 = 0.99). the fe3o4@sio2-n2s mnps can simultaneously adsorb pb2+, cd2+ and cu2+. the reusability of fe3o4@sio2-n2s was utilized at five cycles and removal of pb2+ and cd2+ conserved above 90%. the results show that the novel amino/thiol functionalized mnps can successfully apply as an efficient and reusable nanosorbent with a high adsorption rate in removing heavy metal ions from wastewater.