Adsorption mechanism of gallium(III) and indium(III) onto {gamma}-Al{sub 2}O{sub 3}
- National Taiwan Univ., Taipei (Taiwan, Province of China)
- National Lien-Ho Coll. of Technology and Commerce, Miao-Li (Taiwan, Province of China). Dept. of Environmental Engineering
The transport of heavy metals in the aquatic environment has long been the primary interest of environmental engineers and geochemists. The adsorption mechanism of trivalent Ga and In onto {gamma}-Al{sub 2}O{sub 3} was investigated using a triple-layer model simulation and pressure-jump technique. Bidentate Ga{sup 3+} and In{sup 3+} and monodentate GaOH{sup 2+}/InOH{sup 2+} are the most likely surface species responsible for Ga(III)/In(III) adsorption. Sorption of Ga(III) and In(III) can be interpreted as an associative process. The adsorption pathway is a two-step mechanism: proton release from surface hydroxyl group(s) followed by coordination of Ga(III)/In(III) species to the depronated site(s). Intrinsic adsorption rate constants cannot be estimated with a liner free-energy relationship between the adsorption rate constant and the rate of water exchange, which is developed solely based on the dissociative sorption mechanism of divalent ions.
- Sponsoring Organization:
- National Science Council, Taipei (Taiwan, Province of China)
- OSTI ID:
- 483813
- Journal Information:
- Journal of Colloid and Interface Science, Vol. 188, Issue 1; Other Information: PBD: 1 Apr 1997
- Country of Publication:
- United States
- Language:
- English
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