Macroscopic and vibration spectroscopic evidence for specific bonding of arsenate on gibbsite.
The As(V) adsorption onto gibbsite under different experimental conditions was examined. Macroscopic data suggests strong As(V) bonding on gibbsite possibly via a bidendate binuclear complexation mechanism. The As(V) adsorption was quantified with the charge distribution multi-site ions complexation (CD-MUSIC) model distributing the anion charge over 0- and 1-planes according to the modified Pauling's bond valence theory. In the dual-adsorbates system of As(III) and As(V), the As(III) adsorption was predicted up to pH 8 utilizing the binding constants derived for single-adsorbate data. However, with pH > 8, the modeled As(III) adsorption data is overestimating the experimental values.
Weerasooriya
R
R
Lehrstuhl für Angewandte Geologie, Universität Erlangen-Nürnberg, Schlossgarten 5, 91054 Erlangen, Germany. rohan@geol.uni-erlangen.de, rweerasooriya@hotmail.com
Tobschall
H J
HJ
Wijesekara
H K D K
HK
Bandara
A
A
D000327:Adsorption; D000536:Aluminum Hydroxide / Q000737:chemistry*; D001149:Arsenates / Q000737:chemistry*; D002849:Chromatography, Gas; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008956:Models, Chemical; D017550:Spectroscopy, Fourier Transform Infrared
D001149:Arsenates; D000536:Aluminum Hydroxide; C025657:arsenic acid