Abstract
The complexation of sulfate ions at the goethite-water interface has been studied by equilibrium measurements at 298.2 ± 0.5 K and by infrared spectroscopy. A unified set of data from potentiometric titrations and batch adsorption experiments were evaluated according to an extended Constant Capacitance Model. The obtained equilibrium model consists of two outer-sphere complexes: ≡FeOH 2 +, SO 4 2− (log β 1,1,1(intr) out = 8.3 ± 0.03) and ≡FeOH 2 +, HSO 4 − (log β 2,1,1(intr) out = 13.5 ± 0.07) and an inner capacitance, C 1, of 4.5 and an outer capacitance, C 2, of 1.8. The outer-sphere model was confirmed by the infrared data and adsorption experiments at different ionic strengths. Furthermore, the infrared measurements provided direct evidence for protonation of the sulfate ions at the interface.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
