Phosphorus (P) fixation is a global problem for soil fertility and negatively impacts agricultural productivity. This study characterizes P desorption of already fixed by using KCl, KNO3, histidine, malic acid as inorganic organic compounds, which are quite common in soil. Goethite, gibbsite, ferrihydrite, well hydroxide mixtures with varying Fe- Al-ratio were selected model substances crystall...

The crystallochemical characterization of magnetic spinels prepared from aqueous solution has been studied primarily by electron microscopy and 5 Fe Mossbauer spectroscopy. . Two synthetic routes investigated : 7Fe have been t : method 1; partial oxidation of Fell solutions " in the presence of NO;; at 100°C, O C , and method 2; reaction of hydrated Fe oxide (ferrihydrite) with Fell ions at roo...

Anthropogenic organoarsenic compounds which were used such as agrochemicals, pesticides, and herbicides can have a potential as a source of arsenic pollution in water. In the process, the adsorption of arsenic onto mineral surface in soil may play an important role to affect arsenic distribution in solid-water interface. However, adsorption structures of organoarsenic compounds on the iron-(oxy...

Ferrihydrite was exposed to U(VI)-containing cement leachate (pH 10.5) and aged to induce crystallization of hematite. A combination of chemical extractions, TEM, and XAS techniques provided the first evidence that adsorbed U(VI) (≈3000 ppm) was incorporated into hematite during ferrihydrite aggregation and the early stages of crystallization, with continued uptake occurring during hematite rip...

The mechanisms of photodegradation of binary iron- and uranium-citrate and ternary iron-uranium-citrate complexes were elucidated. Citric acid degradation products were identified by HPLC and GC, and the metal precipitates were identified by XRD and EXAFS. Photodegradation of a binuclear iron-citrate complex occurred as a result of two one-electron oxidations of citric acid with the formation o...

This review focuses on the detailed characterization of proton and metal reactivity on the surface of bacteriogenic iron oxides (BIOS). This substance is composed of a highly porous matrix of ferrihydrite intermixed with intact and fragmented Gallionella ferruguinea cells. Studies concerning proton and metal cation binding to the BIOS were designed to assess their surface chemical heterogeneity...

Previous studies demonstrated the environmental and economic benefits of treating lead(II)-contaminated water streams with ferrihydrite in multiple equilibrium sorption stages. In this work, multistage ferrihydrite sorption systems were evaluated for their effectiveness in reducing single-solute zinc(II) (Zn(II)) concentrations in contaminated water streams to very low levels. As for lead(II) (...

Magnetotactic bacteria biosynthesize magnetite nanocrystals (magnetosomes) with high chemical purity, species-specific crystal morphology on shape and size, and narrow size distribution. These magnetosomes allow the bacteria to orient and navigate along the geomagnetic field lines. The interest in these bacteria has recently increased because of the potential biomedical applications of the magn...