Experimental study of aqueous and mineral surface al-aniline and al-2-chloroaniline complexation

• Main Author: Yane, Lawrence.
• Other Authors: Fein, Jeremy (advisor)
• Format: Others
• Language: en
• Published: McGill University 1997
• Subjects: Geochemistry.
• Online Access: http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=27921

In order to model the transport and fate of aniline and chloroaniline in the subsurface, the geochemical reactions between these contaminants and important metals and minerals surfaces must be quantified. === The thermodynamic stabilities of the aqueous and surface aluminum-aniline and aluminum-2-chloroaniline complexes were investigated at 55$ sp circ$C and 80$ sp circ$C. Solubility and adsorption experiments place quantitative constraints on the thermodynamic properties of these complexes. No evidence was found for stable Al-aniline or Al-2-chloroaniline aqueous complexes. Conversely, the adsorption data provide unequivocal evidence for the presence of two distinct surface Al-aniline and A-chloroaniline complexes according to the following reactions: (1) $Aniline sp circ + { equiv}Al(OH) sp circ leftrightarrow { equiv}(AlOH(Aniline) sp circ$; (2) $Aniline sp circ + { equiv}Al(O) sp- leftrightarrow { equiv}AlO(Aniline) sp-$; (3) $Chloroaniline sp circ + { equiv}Al(OH) sp circ leftrightarrow { equiv}AlOH(Chloroaniline) sp circ$; (4) $Chloroaniline sp circ + { equiv}Al(OH sb2) sp+ leftrightarrow { equiv}AlOH sb2(Chloroaniline) sp+$. === A constant capacitance model is used to quantify the stability constants for reactions (1) - (4), and the results yield equilibrium constant values of 10$ sp{2.09}$, 10$ sp{2.67}$, 10$ sp{2.87}$ and 10$ sp{2.30}$ respectively. These results indicate that mineral surface complexation can significantly affect total aniline and chloroaniline budgets.