The mechanism of sulfate adsorption on goethite was investigated in situ using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. Sulfate adsorption was investigated at ionic strengths between 0.005 and 0.1 M, reactant concentrations between 5 and 500 µM, and pH values between 3.5 and 9.0. It was determined that sulfate forms both outer-sphere and inner-sphere surf...

-Competitive adsorption between glyphosate and phosphate on goethite was evaluated. The influence of background electrolyte on the adsorption of glyphosate and phosphate was also investigated by using 0.01 M KC1, 0.1 M KC1 and 0.01 M CaCI 2 as background electrolytes. Experiments showed that phosphate displaced adsorbed glyphosate from goethite, whereas glyphosate did not displace phosphate. Re...

The aqueous solubility of oxyanion (e.g. phosphates and arsenates), and thereby their mobility, bioavailability (phosphates) and toxicity (arsenates), in soils and sediments is dependent upon their chemical speciation. In complex, multicomponent systems, equilibrium modelling can be a useful tool to predict chemical speciation. When establishing a model, it is essential to understand the intera...

In order to better understand the influence and mechanism of soil-derived humic acid (SHA) on adsorption of P onto particles in soils, the amounts of PO4 adsorbed by synthetic goethite (a-FeOOH) were determined at different concentrations of SHA, pH, ionic strength and order of addition of adsorbents. Addition of SHA can significantly reduce the amount of PO4 adsorption as much as 27.8%. Both g...

Phenolic compounds are one class of organic contaminants with high toxicity. In the present work, we study the degradation of 3,5-dimethylphenol (3,5-DMP) in heterogeneous phase with Fe(III)(hydr)oxides (goethite). The transformation of 3,5-DMP in aqueous suspension has been investigated under monochromatic irradiation at 365 nm. The disappearance of 3,5DMP was efficient upon irradiation of 3,5...

The adsorption of diclofenac (DCF), one of the widely used non-steroidal anti-inflammatory drugs, onto the surface of goethite was investigated with batch experiments. The adsorption at different pH values (5.3, 7.4, and 10.0) were well fitted with the pseudo-second-order model. The results showed that the adsorption of DCF onto goethite was strongly depended on solution pH. The amount of adsor...

This research probes the mechanisms of Zn adsorption on hydrated oxides of iron (HFO and goethite) using XAS. A systematic investigation reveals that Zn2+ upon sorption to HFO retains its hydration shell (N∼ 6 oxygens, R∼ 2.18 Å), irrespective of pH and adsorbate loading. Furthermore, the absence of second-shell contributions in combination with the temperature dependence of the structural para...

We have performed extended X-ray absorption fine structure (EXAFS) analysis for artificial Cr-goethite to elucidate the local structure around Cr in Cr-goethite. The spectra were obtained using synchrotron radiation X-rays at the Photon Factory in Tsukuba. The first shell contributions were isolated by Fourier filtering the EXAFS data, and the inverse Fourier transformed single-shell data were ...

Limpet teeth are striking examples of a biological fibrous nanocomposite consisting of goethite mineral within a polymeric chitin matrix. The mechanical function of limpet teeth is critically dependent on the efficient composite behaviour of goethite, formed as distinct discontinuous nanofibres, reinforcing the matrix. The mechanical properties of discrete volumes from a limpet tooth measured u...

Hematite and goethite are the two most abundant iron oxides in natural environments. Their formation is controlled by multiple environmental factors; therefore, their relative concentration has been used widely to indicate climatic variations. In this study, we aimed to test whether hematite and goethite growth is influenced by ambient magnetic fields of Earth-like values. Ferrihydrite was aged...