Kinetics of Cr(III) Adsorption/Desorption at the γ-Al2O3/Water Interface by the Pressure-Jump Technique

✍ Scribed by Kuen-Sen Chang; Cheng-Fang Lin; Dar-Yuan Lee; Shang-Lien Lo; Tatsuya Yasunaga

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 359 KB
• Volume: 165
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1994.1218

✦ Synopsis

Mechanistic information regarding (\mathrm{Cr}) (III) adsorption onto (\gamma-\mathrm{Al}{2} \mathrm{O}{3}) was obtained using the triple layer model (TLM) in conjunction with experimental data gathered using the pressurejump technique. Adsorption data and TLM simulation results suggest the formation of both mono- and bidentate inner-sphere (\mathrm{Cr}^{3+}) or (\mathrm{CrOH}^{2+}) complexes at the surface of (\gamma-\mathrm{Al}{2} \mathrm{O}{3}). The mechanism of (\mathrm{Cr}) (III) sorption was interpreted as proton release from surface hydroxyl group(s) followed by the attachment of (\mathrm{Cr}^{3+}) or (\mathrm{CrOH}^{2+}) to form bidentate (SO) ()_{2} \mathrm{Cr}^{+})and monodentate (\mathrm{SOCrOH}^{+}). The binding constant of (\mathrm{Cr}^{3+}) or (\mathrm{CrOH}^{2+}) with deprotonated reacting site(s) simulated using the TLM and equilibrium sorption data was in excellent agreement with that determined from kinetic results, verifying the proposed reaction mechanisms. (1994 Academic Press, lnc.