Inorganic Ligand Effects on Pb(II) Sorption to Goethite (α-FeOOH)

Adsorption of Sulfate and Copper(II) on Goethite in Relation to the Changes of Zeta Potentials

“…7 and 9), and the decrement becomes smaller if the supporting electrolyte of 0.01 M NaNO 3 is added. These are generally opposite to those reported previously (7,8,27). Satisfactory explanation cannot be given at this stage.…”

“…In SO 2− 4 -free systems, ≡FeOCu + is the dominant species; however, at higher SO 2− 4 concentrations (>0.25 mM), the complex ≡FeOHCuSO 4 is dominant at pH < 5. On the other hand, Ostergren et al (27) found that enhanced affinity of Pb-SO 2− 4 complexes relative to free Pb 2+ for goethite surface is responsible at least in part to reducing the electrostatic barrier that Pb(II) must overcome when sorbing to a positive surface (pH < pH zpc ). In contrast, increased SO …”

“…The strong ionic strength dependence of SO 4 binding continues even in the recent spectroscopic studies; e.g., the diffuse reflectance spectra (24) and in situ attenuated total reflection-FTIR data (25,26). Such discrepancies may be due to differences in analytical tools or disagreements about peak identification (27).…”

In situ Fourier-transform infrared spectroscopy studies of inorganic ions adsorption on metal oxides and hydroxides

“…Thus, the subtraction of the spectra recorded with and without metal leads to the spectrum of the sulfate bonded with the metal ion. Ostergren et al [60] identified the ternary complex as (≡Fe-O) 2 Pb-OSO 3 , which is in agreement with the following similar study by Elzinga et al [30].…”

“…3), according to an IS complex with a C 3v symmetry, two Lorentzians for the split ν 3 (1055 and 1130 cm -1 ) and a Lorentzian for ν 1 (975 cm -1 ). Spectra recorded on sulfate-treated goethite [11,60] were very similar to those obtained on hematite [12] but two Gaussian peaks attributed to an OS complex (degenerated ν 3 at 1108 cm -1 and ν 1 at 975 cm -1 ) were included along the Gaussian peaks coming from an IS complex with a C 2v (C 1 ) symmetry (ν 3 at 1170, 1133 and 1055 cm -1 , and ν 1 at 922 cm -1 ) (Fig. 4).…”