Adsorption Properties Of Pb Research Articles

The adsorption properties of Pb(II) and Cd(II) on functionalized graphene prepared by electrolysis method

The functionalized graphene (GNS PF6) was fabricated by simple and fast method of electrolysis with potassium hexafluorophosphate solution as electrolyte under the static potential of 15 V. The characterization results of transmission electron microscopy, atom force microscopy, X-ray photoelectron spectroscopy, X-ray powder diffraction, Raman spectroscopy and thermogravimetric analysis indicate that graphite rod was completely exfoliated to graphene layer containing 30 wt.% PF 6ˉ with the average thickness ca. 1.0 nm. Our sample of GNS PF6 was developed for the removal of Pb(II) or Cd(II) ions from water, and the determined adsorption capacities are 406.6 mg/g (pH = 5.1) for Pb(II) and 73.42 mg/g (pH = 6.2) for Cd(II), which is much higher than that by our previous sample of GNS C8P and carbon nanotube. The adsorption processes reach equilibrium in just 40 min and the adsorption isotherms are described well by Langmuir and Freundlich classical isotherms models.

Lead(II) Adsorption from Aqueous Solution by Poly(ethylene terephthalate)-g-Acrylamide Fibers

In this study, a reactive fibrous adsorbent was prepared by graft copolymerization of Acrylamide (AAm) onto poly(ethylene terephthalate) (PET) fibers and the adsorption properties of Pb(II) ion from aqueous solution by the reactive fibers were examined by batch equilibration technique. The effects of graft yield, pH, adsorption time, initial ion concentration and adsorption temperature on the adsorption amount of Pb(II) ion was studied. The results show that the adsorption amounts of Pb(II) ion increased with grafting yield, shaking time, initial ion concentration and adsorption temperature. Adsorption of Pb(II) ion was strongly affected by pH. A Lagergren pseudo-second-order was the model that best described the adsorption mechanism. It was found that the adsorption isotherm of the Pb(II) ion fit Langmuir-type isotherms. From the Langmuir equation the adsorption capacity was found as 39.57 mg/g fiber for Pb(II) ion for the copolymer with a graft yield of 15.7%. Quantitative desorption of Pb(II) from reactive fibers were found to be 96% by 5 M HNO3. Five adsorption–desorption cycles demonstrated that the reactive fibers were suitable for repeated use without considerable change in adsorption capacity. The results of the thermodynamic study indicated that the adsorption processes was endothermic and spontaneous.