Surface Complexation of Calcium Minerals in Aqueous Solution: 4. The Complexation of Alizarin Red S at Fluorite–Water Interfaces

✍ Scribed by Liuming Wu; Willis Forsling; Allan Holmgren

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 197 KB
• Volume: 224
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1999.6692

✦ Synopsis

The complexation of Alizarin Red S (ARS) at the surface of hydrous fluorite particles has been investigated by means of potentiometric titrations, adsorption experiments, and zeta-potential measurements in 0.1 mol dm(-3) KCl ionic medium at 25.0 degrees C, as well as by UV/visible specular reflectance, FT-IR, and FT-Raman spectroscopy. Chemical reaction models describing the equilibria of ARS (HA(2-)) at the aqueous fluorite surfaces ( identical withX) have been established as follows: Experimental data were evaluated using the computer program FITEQL on the basis of a constant capacitance model for the electric double layer. Surface complexation mechanisms involving the R-SO(3)(-), R-beta-OH, and R-alpha-OH active groups of the ARS molecule are proposed to describe coordination to the fluorite surface. Copyright 2000 Academic Press.