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Synthesis And Performance Of A Nano-Fe~0Complex Chelating Adsorbent

Posted on:2014-05-20Degree:MasterType:Thesis
Country:ChinaCandidate:Y M LiuFull Text:PDF
GTID:2251330422950241Subject:Environmental Engineering
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In the paper, the nano-Fe0complex chelating adsorbent (Fe0/PEI, Fe0/PP) was synthesizedby cross-linking reaction of nano-Fe0with polyethyleneimine (PEI) and polyethylenepolyamine (PP), respectively. The optimum synthetic conditions, the properties of thecomplex chelating adsorbent on the removal of Cr6+, Pb2+, Ni2+and the removal mechanismwere studied. The physicochemical structures and morphology of Fe0/PEI and Fe0/PP werecharacterized by FT-IR, SEM, XRD and XPS. The results showed that the optimum syntheticconditions is that glutaraldehyde act as cross-linking agent, PEI or PP: nano-Fe0is1:4(w:w),20℃and stirring for4h. The chelating adsorptions tended toward equilibrium at60min andthe monolayer adsorption saturation capacity (Q0) of Fe0/PEI and Fe0/PP for Cr6+were165.25and138.65mg·g-1respectively at20℃. Adsorption kinetic data were found to follow thepseudo second-order model and the equilibrium data fitted very well with the Langmuirequation. Intra-particular diffusion could be accepted as the primary rate determining step.Thermodynamic parameters, involving△H,△S and△G were also calculated fromgraphical interpretation of the experimental data. Negative values of△G indicated thatchalating adsorption processes for Cr6+were spontaneous. The maximum capacity ofadsorption occurred under intermediately acidic conditions. The mechanism research showedthat Cr6+was reducted to Cr3+by the nano-Fe0in Fe0/PEI and Fe0/PP, meanwhile nano-Fe0was oxidated to Fe3O4.
Keywords/Search Tags:Polyethyleneimine, Polyethylene Polyamine, Chelation, Nano-Fe~0, Cr6+
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